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Purpose: Maxillary sinus floor augmentation is a safe and predictable technique used to increase
bone volume under sinus cavity for implant placement in atrophic posterior maxilla before
implant placement. Despite conflicting results concerning the new bone formation rates with or
without a barrier membrane, the benefits of using a collagen membrane to cover the lateral bone
window has been demonstrated, in order to prevent bone substitute particles dislodgement that
may occur from the sinus cavity through the sinus antrostomy towards the oral mucosa, and to
significantly reduce the postoperative swelling and pain reactions. The purpose of this case series
is to present a sling suture technique used to stabilize the collagen membrane against the lateral
bone window so as to improve the bone substitute stability inside the sinus cavity. Materials and
Methods: Maxillary sinus floor augmentation with lateral approach using sling suture technique
to maintain the collagen membrane against the lateral bone window was performed in 17 patients
(8 women/ 9 men, mean age: 58.2 years). Postoperative cone-beam computed tomography
(CBCT) images up to 6-month follow-up were performed to control the bone graft stability at the
level of the lateral antrostomy. The clinical postoperative pain and swelling were assessed
through a Visual Analogue Scale (VAS) questionnaire from level 1 (low), level 5 (acceptable), to
level 10 (high) at one week postoperative. Results: No bone substitute displacement was
observed for all clinical cases on the CBCT images at 6-month postoperative. The pain and
swelling level observed at one-week post operative were significantly low (respectively
1.6±1.0/2.1± 0.9). Conclusions: Within the limits of this case series, the use of sling suture
technique to maintain the barrier membrane at the level of the lateral bone window in case of
maxillary sinus floor augmentation with lateral approach surgery revealed to be a predictable
protocol to prevent bone substitute displacement outside the sinus cavity.
Purpose: To evaluate bone preservation and aesthetic recovery between the socketshield
technique (SST) with different labial bone plate thicknesses and the
conventional immediate implant technique (CIIT). Materials and Methods: Patients
who underwent immediate implant placement in the anterior region were divided into
three groups: the SST with a thick-wall phenotype (> 1 mm) (SSTA group), the SST
with a thin-wall phenotype (< 1 mm) (SSTB group) and the CIIT with a thick-wall
phenotype (> 1 mm) (CIIT group). Radiological images and clinical photos were
collected before surgery and immediately and six months postoperatively. The labial
bone width and labial bone width change (BWC), labial bone volume change (BVC),
pink aesthetic score (PES) and complication rate were evaluated among the three
groups. Statistical analysis was performed using SPSS software. Results: Twenty
people in each group (60 people total) were enrolled in this six-month retrospective
study. The BWC in the SSTA group (0.22-0.30 mm) and the SSTB group (0.18-0.33
mm) was less than that in the CIIT group (0.61-0.80 mm, p<0.004). The SSTA group
and the SSTB group had a lower BVC (24.08 vs. 21.14 vs. 54.81, p=0.004) and
greater PES (11.75 vs. 11.65 vs. 10.65, p=0.009) than the CIIT group. No
complications occurred among these patients. Conclusions: With the limitations of
this study, we can conclude that the SST is a reliable method for preserving bone and
achieving satisfactory aesthetic outcomes. The labial bone plate phenotype associated
with the SST has minimal impact on both clinical and radiological outcomes.
Purpose: The purpose of this study was to examine the mechanical influence of
edentulous mandibular morphology on peri-implant bone in implant prosthetics by
finite element analysis. Materials and Methods: Computed tomographic data from 25
patients with edentulous mandibles were selected and the radius of mandibular
curvature and the height of the mandible at the midline were measured in order to
clarify the morphological characteristics of the mandible. From the measurement, two
patients with the smallest and largest radii of the mandible were selected. Two types of
three-dimensional finite element models consisting of the edentulous mandible (small
and large radius), superstructure (a cantilever bridge), implants, and abutments were
created. Four implants were inserted between the right and left mental foramina. The
upper surface of the mandibular condyle was constrained, and a vertical load of 100 N
was applied on the occlusal surface of the right first molar. Three-dimensional finite
element analysis of each model was performed to examine the mechanical influence of
the edentulous mandibular morphology on the peri-implant bone. Results: Measurement
of mandibular morphology in CT images indicated that the lower the mandibular height
was, the larger was the radius of the anterior mandibular curvature. Finite element
analysis revealed that a higher equivalent stress was generated in the peri-implant bone
of the model with a larger radius of curvature than that of the model with a smaller
radius of curvature. The highest equivalent stress in the mandible was generated in the
distal margin of the peri-implant bone posterior to the loaded side of the large radius of
curvature model. Conclusions: The mandibular morphology had a mechanical influence
on the peri-implant bone.
Purpose: This study aimed to assess the accuracy and precision of prosthetically-driven
implant placement achieved through static computer-aided implant surgery. The primary
objective was to analyze the linear and angular deviations of dental implants in patients
treated at a university dental clinic. Various types of surgical techniques and templates
were utilized to optimize implant positioning. Materials and Methods: A total of fiftythree
dental implants were included in this study. The implants were positioned using
either tooth-supported templates or tooth-tissue-supported templates with fixation pins.
Two distinct guided surgery approaches were used, these being pilot drill guided and
fully guided. Three-dimensional (3D) data from the implant planning phase was
superimposed with the 3D data from the final implant positions using the ‘Treatment
Evaluation’ tool within CoDiagnostix. implant planning software (Straumann AG).
This enabled the automatic calculation of deviations in implant placement accuracy.
Results: Average angular deviation observed was 3.90 degrees. For linear deviations,
the mean 3D deviation at the most coronal point of the implants was 1.04 mm, while at
the implant apex it was 1.56 mm. Conclusion: This research demonstrates the
feasibility of a digital workflow for guided implant surgery, offering a promising
treatment option. Nonetheless, it is important to note that deviations do occur, with the
apical region of the implant being the most affected area. Care should be taken,
particularly in cases of limited bone availability.
Purpose: Marginal bone resorption (MBR) around oral implants may sometimes be a selflimiting
condition due to balancing immunological reactions against the utilized materials,
rather than a progressive bacterial infection. Contrary to previous assumptions from ligature
induced experimental peri-implantitis studies, our recent 8-week experiment showed that
marginal ligatures per se trigger an inflammatory immune response, resulting in bone
resorption around implants in absence of a plaque. The present study aims to investigate
whether this inflammatory/immunological reaction attenuates or progresses toward implant
failure after a longer healing time, 12 weeks. Materials and Methods: Sterile silk ligatures
were placed around the top of titanium (Ti) implants and compressed against the femoral
cortical bone plate of 6 rabbits. A non-ligated implant was used as control. After 12 weeks of
submerged healing, ground sections of implants and surrounding tissues were investigated
with light microscopy. The marginal soft tissues were also analyzed using selected qPCR
markers. Results: Histologically, the ligatures were outlined by immune cells, including
multinucleated giant cells (MNGC), with adjacent fibrous encapsulation and resorbed
peripheral bone that contrasted from the osseointegrated non-ligated control implants. The
difference in expression of qPCR markers was not significant, but >2-fold upregulation of
markers CD11b, IL1b, ARG1, NCF1, CD4 and >2-fold downregulation of CD8 indicated a
mild, focal inflammatory/immune response against the ligatures compared to controls, with
upregulation of M1 and M2 macrophages, neutrophils and helper T-cells and downregulation
of killer T cells. Further, the bone formation markers OC and ALPL were >2 fold down
regulated, consistent with the lack of osseointegration of the ligatures, compared to control
implants. Conclusions: Marginal silk ligatures per se trigger an inflammatory/immune
response and aseptic bone resorption around oral implants. Compared to our previous 8-week
study, the inflammatory reaction against the silk appears to attenuate with time, with only a
mild persisting inflammation that may block osseointegration and instead maintains a fibrous
tissue encapsulation type reaction. This may explain why traditional ligature experiments
have required regular exchange of ligatures in order for the bone resorption to progress.
Purpose: Laser-created titanium surface topographies enhance soft tissue attachment and implant
stability. However, knowledge about the underlying mechanisms governing the tissue-level
reaction is lacking. The objective of this study was to examine the behavior and function of
human gingival fibroblasts growing on healing abutments with or without laser-textured
topography. Materials and methods: Human primary gingival connective tissue fibroblasts were
cultured on healing abutments with machined or laser-textured (Laser-Lok, BioHorizons)
surfaces. Cellular and molecular responses were evaluated by cell density assay (WST-1),
fluorescence microscopy, qRT-PCR, and detachment test. Results: The machined surface showed
mono-directional traces and scratches from milling, whereas the laser-textured surface showed a
distinct morphology consisting of mono-directional meso-scale channels (15 μm pitch) and
woven, oblique micro-ridges formed within the channel. There were no differences in initial
fibroblast attachment, subsequent fibroblast proliferation, nor collagen production between the
machined and laser-textured surfaces. Fibroblasts growing on laser-textured surface spread
mono-directionally along the meso-channels, while cells growing on machined surfaces spread
randomly. Fibroblasts on laser-textured surfaces were 1.8-times more resistant to detachment
than those on machined surfaces. An adhesive glycoprotein (fibronectin) and trans-membrane
adhesion linker gene (integrin beta-1) were upregulated on laser-textured surfaces. Conclusions:
The increased fibroblast retention, uniform growth, increased transcription of cell adhesion
proteins compellingly explain the enhanced tissue-level response to laser-created, hybrid textured
titanium surfaces. These results provide a cellular and molecular rationale for the tissue
reaction to this unique surface and support its extended use from implant fixtures and healing
abutments to diverse prosthetic components where enhanced soft tissue responses would be
Schlagwörter: Laser-Lok, microchannels, abutments, implant, soft tissue attachment, laser-textured
Purpose: To investigate the effect of lateral sinus floor elevation (LSFE) on sinus membrane
(SM) thickness and sinus health in mucosa thickness less and more than 5 mm. Materials and
Methods: LSFE was performed in a prospective controlled clinical trial on two groups with less
than and more than 5 mm (group A & B) SM thickness and followed for 6 months. Using
preoperative and 6-month postoperative CBCT and clinical evaluation, SM thickness changes
(primary outcome variable), sinus health, augmented bone height, and length (augmentation
adequacy), membrane–related variables, and operation time were measured. Results: Forty
unilateral sinus augmentations (A:20, B:20) with simultaneous installation of 52 fixtures were
performed on 40 subjects (72.5% males, mean age of 48.8±7.6). The mean preoperative and 6-
month SM thicknesses in group A and group B were 1.4±0.9 and 1.3±0.6 mm, and 6.8±1.0 and
3.4±1.7 mm, respectively. The mean postoperative SM thickness significantly decreased
(P<0.001) only in group B. The mean SM thickness changes also revealed a noticeable
difference between the two groups (P<0.001). Augmentation adequacy and membrane
perforation rate were similar in both groups. Clinical and radiographic rhinosinusitis was not
detected in any of the patients. Bleeding during separation and resistance to elevation in group B
were significantly higher than in group A (P=0.003, P=0.001). Surgical time in group B (12.08 ±
8.26 minutes) was longer than in group A (8.64 ± 3.70 minutes), without reaching a significant
level (P=0.097). Conclusions: LSFE in thickened mucosa (≤10 mm) and thinner mucosa (≤5
mm) does not cause abnormal changes in the sinus membrane and sinus health. LSFE in
thickened mucosa results in adequate sinus augmentation. Thickened SM also shows a
significant thickness reduction. The thickened membrane does not appear to be a
contraindication to SFE.
Schlagwörter: Sinus floor elevation, Schneiderian membrane, sinus membrane, mucosal thickness, ostium patency
Purpose: To investigate the esthetic outcomes based on the color differences in zirconia of
varying thickness, resin cement color, and types of titanium implant surface treatments.
Materials and Methods: Twenty-eight HTMZ specimens were arranged into four groups based
on zirconia thickness: 1.0, 1.5, 2.0, and 2.5 mm (n=7). Each group was tested using two resin
cement colors (n=7) (clear and opaque) in combination with six surface-treated titanium groups
(n=7): untreated titanium (UT), anodization (AN), 50-μm alumina airborne-particle abrasion
followed by AN (SBAN), AN followed by 50-μm alumina airborne-particle abrasion (ANSB),
95% hydrofluoric acid followed by AN (HFAN), and AN followed by 95% hydrofluoric acid
(ANHF) for the 48 experimental groups, and using composite resin (n=7) (A2D) for the four
control groups. All the specimens were measured using a spectrophotometer and subsequently
compared with composite resin (control) with the corresponding zirconia thickness to establish
the color differences. A color difference of <2.7 was considered clinically acceptable. The data
obtained were statistically analyzed using the analysis of variance and post hoc test (p=0.05).
Results: Zirconia thickness, resin cement color, and type of titanium implant surface treatment
significantly affected the observed color differences (p<0.05). When using 2.5-mm HTMZ with
clear resin cement on AN, UT, SBAN, HFAN, and ANSB, the mean color differences obtained
were below the clinically acceptable values. However, when using 2.5-mm HTMZ with clear
resin cement on AN, UT, and SBAN, the 95% confidence intervals of color differences obtained
were below the clinically acceptable values. Conclusions: HTMZ with a minimum thickness of
2.5 mm and clear resin cement on AN, UT, and SBAN groups potentially result in acceptable
color matching with 95% confidence intervals.
Schlagwörter: anodize, cement, ceramic, color, spectrophotometer, zirconia
Purpose: Despite the high clinical accuracy of dynamic navigation, inherent sources of error
exist. The purpose of this study was to improve the accuracy of dynamic navigated surgical
procedures in the edentulous maxilla by identifying the optimal configuration of intra-oral
points that results in the lowest possible registration error for direct clinical implementation.
Materials and Methods: Six different 4-area configurations were tested by 3 operators against
positive and negative controls (8-areas and 3-areas, respectively) using a skull model. The
two dynamic navigation systems (X-Guide® and NaviDent®) and the two registration
methods (bone surface tracing and fiducial markers) produced four registration groups. The
accuracy of the registration was checked at the frontal process of the zygoma. Intra- and
inter- operator reliability for each registration group were reported. Multiple comparisons
were conducted to find the best configuration with the minimum registration error. Results:
Ranking revealed one configuration in the tracing groups (Conf.3) and two configurations in
the fiducial groups (Conf.3 and Conf.5) that had the best accuracy. When the inferior surfaces
of the zygomatic buttress were excluded, fiducial registration produced better accuracy with
both systems (p 0.006 and <0.0001). However, tracing 1 cm areas at these surfaces bilaterally
resulted in similar registration accuracy as placing fiducial markers there (p 0.430 and 0.237).
NaviDent® performed generally better (p 0.049, 0.001 and 0.002) albeit having a wider
margin of uncertainty in the obtained values. Changing the distribution of the 4 tracing areas
or fiducial markers had a less pronounced effect with X-Guide® than with the NaviDent®
system. Conclusion: For edentulous maxillary surgeries, 4 fiducial markers placed according
to configuration 3 or 5 result in the lowest registration error. Where implants are being placed
bilaterally, an additional 2 sites may reduce the error further. For bilateral zygomatic implant
placement, it is optimal to place 2 fiducials on the inferior surfaces of the maxillary
tuberosities, other 2 on their buccal surfaces, and 2 on the anterior labial surface of the
alveolar bone. Utilising the inferior zygomatic buttress is recommended over the inferior
maxillary tuberosities in other types of maxillary surgeries.
Schlagwörter: Dynamic Navigation, Fiducial, Implants, Maxilla, Registration, Tracing
Background: Simvastatin (SMV), a lipid lowering drug, can modulate the process of bone regeneration at the molecular and cellular levels. Its effect on the osseointegration of implants has been studied extensively on animals with assuring results with limited research on human subjects.
Aim: To estimate the effect of simvastatin gel in the osseointegration of dental implants using bone scintigraphy,
Materials and Methods: 20 participants with missing mandibular first molars and D2 type bone were assigned equally to Group A receiving 1.2% simvastatin and Group B receiving Placebo gels during the placement of implants. The participants were subjected to bone scintigraphy to determine the osteoblastic activity at baseline, 30th day and 90th day after implant placement.
Results: Group A revealed a significant increase in osteoblastic activity between baseline, day 30 and 90 (P<.05) with a higher mean of 100.06±21.644% on day 30. Group B revealed a significant increase in osteoblastic activity only between baseline and day 30, and baseline and day 90 (P<.05) whereas there was no difference between day 30 and 90 (P>.05) with a higher mean of 79.20±18.255% on day 30. Bivariate analysis at different time periods revealed a significant difference between groups A and B on day 30.
Conclusion: Implants placed with 1.2% simvastatin gel showed enhanced osteoblastic activity on the fourth week of implant placement, indicating faster rate of osseointegration at an early stage.
Schlagwörter: Simvastatin, Osseointegration, Osteoblastic activity
Purpose: This in-vitro study aims to investigate whether the wettability of two zirconia implant
disk surfaces is affected by glycine and erythritol air-polishing, using saline, bovine serum
albumin, bovine thrombin, and bovine artificial blood as the testing mediums. Materials and
Methods: Zirconia disks were provided by two implant companies: SDS. (Swiss Dental
Solutions, Plymouth, MA, USA) (n=6) and Patent. (Zircon Medical AG, Altendorf,
Switzerland) (n=6). Surface parameters (Sa, Sz, Sdr, Ssk, Sku, and Spd) were measured to
determine their initial surface roughness. Air-polishing was completed using glycine or erythritol
powders using the AIRFLOW. PERIO device (Manufactured by Electro Medical Systems
(EMS)). The wettability of the disk surfaces was evaluated by the contact angle analysis applied
on treated and untreated disks using four wetting solutions, saline, bovine serum albumin (BSA),
bovine thrombin, and bovine artificial blood. In total, 720 contact angle measurements were
completed with n=30 per group. Statistical analysis was performed using the one-way analysis of
variance and post-hoc Tukey HSD test. Results: The results indicate SDS. has a greater
wettability than Patent. before and after air-polishing. The wettability of surfaces treated with
glycine was hydrophobic in some cases. Erythritol increased the surface wettability of zirconia
disks compared to glycine. BSA and bovine artificial blood had lower contact angles than saline
and bovine thrombin for both untreated disks. Conclusions: The initial wettability of zirconia
disks differs between manufacturers, and air-polishing with erythritol powder increases the
wettability of zirconia implant disks for saline, bovine serum, bovine thrombin, and bovine
Schlagwörter: contact angle, erythritol, glycine, wettability, zirconia
Purpose: To evaluate the influence of immediate loading on osseointegration and bone density of
implants installed in a healed alveolar bone crest and supporting single crowns. Materials and
Methods: Two solid titanium transmucosal mini-screws were inserted in the distal regions of the
mandible in 14 patients. One mini-implant was immediately functionally loaded, whereas the other was
left unloaded. After two months of healing, biopsies were retrieved and new bone, old bone, and total
bone (new and old bone) were assessed. Results: Histological examination was performed on biopsies
This peer-reviewed, accepted manuscript will undergo final editing and production prior to print publication.
from 12 patients (n=12). New bone-to-implant contact percentage (BIC%) was 40.3 ± 16.8 % and 55.1
± 19.1 % (p=0.043) at the unloaded and loaded sites, respectively, while the total BIC% was 44.9 ±
17.0 % and 59.5 ± 18.8 %, respectively (p=0.034). The new bone density was 45.9 ± 11.6 % and 45.9 ±
16.7 % in the unloaded and loaded implants, respectively (p=0.622). Conclusions: Immediate loading
positively affected bone apposition on the implant surface, while no effect on bone density was
observed after 2 months of healing.
Schlagwörter: immediate dental implant loading, implant supported prosthesis, clinical trial, osseointegration, biopsy
Purpose: This retrospective clinical follow-up study assesses double-crown retained implanttooth-
supported removable partial dentures (DCR-ITSRPDs) survival, evaluates abutment
survival and identifies first aftercare measures. Materials and Methods: The influence of various
factors on the survival of the DCR-ITSRPDs and the abutments were observed in this
retrospective clinical follow-up study using Kaplan-Meier estimate. In addition, the first occurred
aftercare measure per prosthesis was evaluated. Results: 47 DCR-ITSRPDs were investigated
(mean observation: 4.3 ± 3.8 years; max. 14.3 years) out of which three (6.4%) had to be
replaced. The 5- and 10- year survival probability for DCR-ITSRPDs was 100% and 75%. A total
of 297 abutments (120 natural teeth and 177 dental implants) were observed, of which 22 (7.4%;
6 teeth and 16 implants) failed. The 5- and 10-year survival probability for teeth was 90.2% and
for dental implants 90.4% and 76.3%. Conclusion: DCR-ITSRPDs are a successful and durable
treatment option for patients with substantially reduced residual dentitions. Both, prostheses and
abutments show good survival times after 5- and 10-years in function. The patient associated
factors tested showed no influence on the survival of DCR-ITSRPs and abutments. Peri implant
infection was the decisive factor for abutment loss, therefore, regular dental prophylaxis and
examinations are of major importance.
Schlagwörter: removable dental prosthesis, double crown, dental implants, tooth-implant supported, survival
Purpose: The objective of this systematic review is to assess the impact of implant placemen at different periods on the aesthetic and clinical outcomes, in the aesthetic zone. Material and Methods: Literature screening was conducted in PubMed, ScienceDirect and Cochrane library databases. Relevant articles were chosen according to selection criteria and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data was collected from studies published from 2017-2022 in English. Results: Nine articles were included, where a total of 495 implants were placed, from which 250 were immediate, 109 early, and 136 delayed. Immediate implants showed no statistical difference in Pink Esthetic Score (PES) contrasted to delayed implants. Immediate implants showed significantly higher PES in comparison to early implants (MD= -0.76 with 95% CI= -1.50 to -0.02; P=0.04). The probing depth (PD) was considerably greater in the immediate implants when compared to delayed (MD= -0.62 with 95% CI= -1.05 to -0.18; P=0.005), and the plaque index (PI) was statistically greater in early implants compared to immediate implants (MD= 0.15 with 95% CI= 0.11 to 0.19; P<0.00001). All other soft tissue outcomes showed equal results. The marginal bone level (MBL) loss was statistically higher in early implants compared to immediate implants (MD= 0.09 with 95% CI= 0.02 to 0.16; P=0.02). Conclusions: immediate implants had significantly superior PES, marginal bone loss, and plaque index results when compared to early implants. The probing depth was significantly higher in the immediate group compared to the delayed group. All other outcomes showed no significant difference between the three implant groups. It is important to highlight the limitations of this review such as the small number of studies included and the few reports on aesthetic indices.
Schlagwörter: dental implant; endosseous dental implant therapy; dental implantation, endosseous; esthetics, dental.
Purpose: The aim of this multi-center cohort study in private practices was to retrospectively determine the Cumulative Survival Rate (CSR) and the marginal bone level change (ΔMBL) around novel hybrid design Tissue-Level (TL) dental implants supporting multiple screw-retained restorations. These implants feature a platform-switched transgingival region at the crestal margin designed to support marginal bone stability and implant survival. Materials and Methods: Implant CSRs were analyzed at implant and patient level using Kaplan-Meier. ΔMBL was measured by comparison of peri-apical radiographs available both at loading and at a follow-up visit with an improved standardized digital methodology based on image gray levels. ΔMBL outcomes were subject to linear mixed regression to identify potential risk factors. Results: A total of 301 TL implants in 69 patients with an average age of 62.6 ± 11.7 years (36-87 years) at the time of implantation were considered for the analysis. All 301 implants were successfully restored and loaded. The 54-month CSRs at the implant and patient levels were 98.9% 95%CI=[96.7;99.6] and 95.3% 95%CI=[86.1;98.5], respectively. ΔMBL after a mean follow-up of 22 ± 10.7 months after loading was 0.00 mm ± 0.57 mm. None of the implant sites showed a marginal bone loss exceeding 1.5 mm. Multivariate regression analysis revealed a significant association between ΔMBL and the loading protocol (p=0.027), but not between ΔMBL and age or transgingival height. Conclusions: The high cumulative survival rates and stable peri-implant marginal bone levels support the use of recent TL implants, with a hybrid design inherited from bone level implant-abutment connection, as a suitable treatment option for restoring partially or fully edentulous patients with a good mid-term prognosis. These results should be complemented by future prospective studies also in a real-world multi-center setup in private practices representing the daily realities of implant treatment.
Schlagwörter: dental implants, retrospective study, cumulative survival rate, marginal bone level, real-world evidence, hybrid design
Natural Coral Particles (NCPs) are a suitable scaffold material for Guided Bone Regeneration (GBR) procedures; it combines the placement of a bone substitute supporting a barrier membrane. Due to increasing sea pollution and the declarations of endangered coral species (KYOTO 1997), they are no longer suitable for the medical industry. Novel domestic corals have been grown under controlled conditions to produce cultivated coral graft (CCG) material. This study aimed to evaluate a new CCG in an in vivo experimental GBR procedure. The calvarias of 8 rabbits were surgically exposed, and circular defects 8 mm in diameter were prepared. One defect was filled with CCG particles (experimental group); the contralateral defect (control group) was spontaneously filled by blood clot. The defects were covered with a collagen membrane. Animals were euthanized after 8 weeks. Histological observations of the defects showed similar bone growth patterns in both experimental and control osteotomies. In the experimental defects, no traces of coral particles were observed. Histometric analysis showed denser bone in the pristine zone (65-66%) than in the peripheral zone for both the control (50%) and experimental defects (31%) (P= NS). The new bone percentage was reduced from the peripheral zone toward the middle and the center of the defect (31%, 32% and 27%, respectively) as the distance from the peripheral pristine bone borders increased. The existing data support the complete degradation of CCG as space-maintaining scaffold for GBR procedures.
Schlagwörter: coral, graft, animal study, GBR, bone, rabbit
Purpose: To assess the handling properties and clinical function of a new class of material, a so-called mineral-organic bone adhesive (Tetranite; TN), which as yet has no precedent in orthopedic or oral and maxillofacial surgery, for clinically unstable implants placed in immediate extraction sockets and immediately temporized in the anterior maxilla. Materials and Methods: A cohort of up to 15 patients requiring between one and four immediate dental implants placed into maxillary extraction sockets from canine to canine were eligible for inclusion. Implants had to be unstable with an insertion torque of < 15 Ncm. Implants were then stabilized using TN, which was allowed to set before reassessing stability using both torque and resonance frequency measurements. Implant stability quotients (ISQs) taken after TN setting were compared to ISQs taken prior to its application, and the implants had to demonstrate resistance to a forward torque of 20 Ncm to be considered stable. ISQs were monitored at 1 week and 1, 3, 7, and 12 months postplacement. In addition, peri-implant tissue health was monitored, adverse events were recorded, and implant success was determined at 1 year postplacement. Results: Eleven patients received a total of 14 implants. Three out of the first 6 implants failed within 1 month (50%), and thus a protocol amendment was made to remove steps considered potentially destructive to the bonding process. As a result of these amendments, only 1 further failure was experienced for the next 8 implants placed (12.5%). Mean ISQ data averaged for buccolingual and mesiodistal measurements demonstrated a baseline value before TN application of 59.1 Ncm (SD: ± 9.7; range 40.5 to 73.0). After final setting of the TN, mean ISQ measured 71.9 Ncm (± 6.5; 56.0 to 80.0). At 3 months, just prior to restoration placement, mean ISQ measured 71.0 Ncm (± 6.6; 57.0 to 78.0). Thereafter, the mean ISQ continued to increase at both the 7- and 12-month follow-ups with scores of 78.9 (± 4.6; 72.0 to 84.5) and 80.3 (± 3.8; 74.5 to 85.0), respectively. The surviving 10 implants went on to be fully restored and remained in function beyond the end of the study period to yield a final success rate of 71.4%. Conclusions: The purpose of a first-in-human study is to demonstrate an extrapolation of preclinical data into the controlled human clinical arena. It is an opportunity to learn what does and does not translate well from experimental data. In that regard, the current pilot study can be deemed a complete success. The implant survival rate of 71.4%, while disappointing, should be considered in light of the protocol amendments identified, the user handling experience learned, and the opportunity to modify the material to better perform in the human patient, as all represent important lessons learned. The notable increase in ISQ sheds light on the nature by which the glue was substituted for bone to yield a stable implant by the end of the study period.
Schlagwörter: bone glue, mineral organic bone adhesive, Tetranite, dental implant, primary stability
Purpose: The objective of this systematic review is to assess the impact of implant placemen at different periods on the aesthetic and clinical outcomes, in the aesthetic zone. Material and Methods: Literature screening was conducted in PubMed, ScienceDirect and Cochrane library databases. Relevant articles were chosen according to selection criteria and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data was collected from studies published from 2017-2022 in English. Results: Nine articles were included, where a total of 495 implants were placed, from which 250 were immediate, 109 early, and 136 delayed. Immediate implants showed no statistical difference in Pink Esthetic Score (PES) contrasted to delayed implants. Immediate implants showed significantly higher PES in comparison to early implants (MD= -0.76 with 95% CI= -1.50 to -0.02; P=0.04). The probing depth (PD) was considerably greater in the immediate implants when compared to delayed (MD= -0.62 with 95% CI= -1.05 to -0.18; P=0.005), and the plaque index (PI) was statistically greater in early implants compared to immediate implants (MD= 0.15 with 95% CI= 0.11 to 0.19; P<0.00001). All other soft tissue outcomes showed equal results. The marginal bone level (MBL) loss was statistically higher in early implants compared to immediate implants (MD= 0.09 with 95% CI= 0.02 to 0.16; P=0.02). Conclusion: immediate implants had significantly superior PES, marginal bone loss, and plaque index results when compared to early implants. The probing depth was significantly higher in the immediate group compared to the delayed group. All other outcomes showed no significant difference between the three implant groups. It is important to highlight the limitations of this review such as the small number of studies included and the few reports on aesthetic indices.
Purpose: This prospective study evaluated the marginal bone level and periodontal parameters 6 years after placement of a convergent transmucosal neck implant. Materials and Methods: In total, 71 implants were placed in 60 patients. Of these, 52 implants were placed with a flapless technique and with the convergent neck exposed for 1.0 mm (early and delayed placement), while 19 implants were placed immediately after extraction (immediate placement). At least 3 months after insertion, customised abutments were applied and provisional resin crowns were cemented, while being careful to prevent any tissue compression. After 3 weeks, definitive metal-ceramic crowns were designed with the finishing line at the soft tissue level and free from any compression. The implant survival rate at 6 years, marginal bone level changes (MBL, mm), and Pink Esthetic Score (PES) were evaluated. Gingival phenotype was determined before the implant surgeries (thin/thick). A three-level hierarchical model was examined with a random intercept and random slope on follow-up time at the patient level, and a random intercept at the implant level. Results: In all, 57 patients with 67 implants reached the 6 year point; 3 (5.0%) dropped out. The implant survival rate was 100%. ΔMBL T0-T24 was 0.58 mm (95% CI 0.48, 0.68), while ΔMBL T24-T72 was 0.33 mm (95% CI 0.19, 0.47). PES improved steadily from 6 to 48 months (+0.96; 95% CI 0.71, 1.20), with overall stability at 72 months. No correlation between MBL and PES was observed. A significant association was found between the gingival phenotype and less MBL variation. Greater implant diameter offered more MBL stability after 3 years, but lower PES values. Conclusion: The use of convergent transmucosal neck implants placed with a flapless transmucosal approach with the crown margin positioned at the gingival level preserved marginal bone and guided gingival morphology for up to 72 months. The gingival phenotype was the parameter that most affected the soft and hard tissues. In the long term, implant placement timing was not related to MBL.
Background: Platelet-rich fibrin (PRF) is used to prepare "sticky bone" by combining it with bone-graft material. The present study investigated the ability of different bone grafts to absorb growth factors from the PRF and release them over time. Methods: Human blood was collected from 10 healthy volunteers for liquid PRF preparation. Bovine bone, allograft (mineralized and demineralized), and synthetic bone were each mixed with the PRF to prepare a sticky bone. All sticky bone samples were incubated for up to 4 days and the absorption and release pattern kinetics of two selective growth factors within the PRF (Platelet-Derived Growth Factor and bone morphogenetic protein 2) were quantified with immunofluorescence staining and ELISA. Results: All the tested bone graft materials adsorbed the examined growth factors from the PRF. β-TCP showed the highest adsorption levels, followed by the xenograft, and the allografts showed the lowest adsorption levels. Furthermore, PDGF showed a fast release pattern from the grafts, whereas BMP2 was released at a later stage. Similar to the adsorption pattern, the β-TCP and xenograft were better able to sustain the release of the PRF growth factors from the graft than the allografts. Conclusions: The adsorption of PDGF and BMP2 differ between graft materials, with superior results for βTCP, followed by xenograft and lastly the allograft materials.
Purpose. The purpose of this clinical study was to determine the accuracy of dental implant placement by using haptic robotic guidance in a large clinical series. Material and Methods. In a prospective single-arm clinical study, 108 patients received 273 individual endosteal implants. A virtual preoperative restorative and surgical plan was created from a cone beam computed tomography (CBCT) scan and matched to the surgical workspace on the day of surgery via either a tooth-based or a bone-based fiducial splint. Intraoperatively, the surgeon manipulated a handpiece attached to haptic robotic guidance arm. A variety of drills and implants were used in this series. Both the osteotomy and the implant placement were guided by 3D haptic constraints according to the virtual plan. A postoperative CBCT scans permitted the calculation of the deviations of the actual implant placement compared to the plan for accuracy. Precision was calculated by comparing standard deviations from published literature.
Results. The implants were evenly distributed by jaw with 47% placed in the maxilla and 53% in the mandible. The mean ± standard deviation signed depth deviation was 0.14 ± 0.87 mm proud. The global angular deviation averaged 1.42 ± 1.53 degrees with 95% confidence limits of 1.24 degrees and 1.60 degrees. The crown of the actual placed implant showed an average deviation from the plan of 1.10 ± 0.69 mm and the apex a deviation of 1.12 ± 0.69 mm. Haptic robotic-guidance showed greater precision than freehand, static computer-guided and dynamic computer-guided implant placement. Conclusion. This large clinical series of 273 implants shows a high accuracy of implant placement in comparison to published accuracy for angular deviations for any technology as well as demonstrating statistically greater precision. Long-term clinical studies are necessary to establish the true effect of increased accuracy on clinical outcomes. Using haptic robotic guidance provides accurate implant placement while allowing additional benefits compared to computer-guided surgery, namely full visualization of the surgical field and the ability to change the plan intra-operatively.
Background: The clinical use of bioactive substances, such as growth factors, have significantly increased, however, potential regenerative effects derived from the addition of different growth factors to bone substitutes on maxillary sinus floor augmentation (MSA) procedures is still controversial. This systematic review (SR) aimed at answering the following question: “Do recombinant, purified and concentrated growth factors enhance the regenerative potential of particulate bone graft substitutes in maxillary sinus floor augmentation?”. Methods: Human studies comparing histomorphometric data of the outcomes of interest new bone formation, residual graft material, and fibrous tissue ratio following MSA procedures employing particulate bone grafts/substitutes in combination or not with growth factors were retrieved from PubMed/MEDLINE, Web of Science, Cochrane and Scopus online databases and complemented with a hand search. Controlled studies published in English up to December 2022 and reporting on histomorphometric data expressed as percent volume of the outcomes of interest were considered. Risk of bias was assessed, and a meta-analysis (MA) was performed to investigate the effects of supplementary growth factors on new bone formation, remaining graft particles and fibrous tissue ratio. Results: Data of 613 samples from 477 patients reported in 22 publications were included. MA showed PRP or PRF resulted in 49% more new bone formation than in areas in control groups (P=0.004), and those areas supplemented with growth factors presented 57% less residual graft particles after healing (P<0.0001). A significant (P=0.03) 1.85-fold increase in connective tissue formation was noted in areas treated with rhBMP after healing. Conclusion: The MA provided evidence that selective supplementary growth factors may enhance new bone formation and accelerate particulate graft turnover, while rhBMP may significantly increase connective tissue formation in MSA procedures in humans.
Purpose: to measure the surface temperature distribution after CO2-laser heating of titanium dental implants using different power settings, application intervals and irradiation times. Materials and methods: 10 tissue-level-type titanium implants (Camlog Screw-line Promote Plus 4.3mm x 11mm) were embedded (Epofix, Struers ApS, Copenhagen, Denmark) and irradiated with a carbon-dioxide-laser (Denta II, Lutronic Corporation, Fremont, USA) with a wavelength of 10.6µm and at power levels of 4watts (group 1), 6watts (group 2), 8watts (group 3) and 10watts (group 4). A continuous beam mode (setting I) and non-continuous beam modes with 5second (setting II) and 10second (setting III) pause intervals were used. For each setting, a total irradiation time of 50seconds was used and repeated 10 times. The temperature was measured using external thermocouples (Testo SE & Co. KGaA, Lenzkirch, Germany) in contact with the implant surface at implant shoulder, middle and apex. A linear regression model was used to analyse the data (p = 0.05). Results: Setting I demonstrated the most rapid increase in implant surface temperature in all three test sites as well as the greatest total temperature at 50 seconds of irradiation time. The greater the pause interval (settings II and III) during the 50 seconds of irradiation, the lower the rate of temperature increase as well as the total temperature in all three test sites and with all power levels. The average temperature difference between the apex and shoulder site was significant for test setting III for all groups, but not for any groups in settings I and II. Conclusion: Heating the internal aspect of a dental implant with a CO2-laser produces different temperature distribution profiles depending on the laser power level and the application interval. Laser-beam irradiation leads to a temperature gradient which is greatest at the implant apex and smallest at the implant shoulder.
Background: The preclinical study presented here compared crestal bone loss between titanium implants with a conventional etched surface (SLA type) and others coated with chitosan, after 12 weeks of immediate implantation in the mandible of a canine model. Material and Methods: Forty-eight implants (24 experimental and 24 control) of Ti-Al16-V4 with an internally connected tapered screw design were randomly inserted into six maxillary canines, four per hemiarch. The experimental implants were coated with Chitosan by immersion and sterilization with ethylene oxide. Primary stability was measured using the Osstell® device. No grafting materials were used, and three-dimensional micro-CT measurements included crestal bone volume (CBV) and bone volume change in crestal area (∆CBV), which were considered outcome measures. Parallelized periapical radiographs were also taken at the time of implant placement and after 12 weeks to assess changes in crestal bone levels. Results: In terms of volumetric changes, it was observed, that the experimental group showed better results than the control group (p=0.049 and p=0.303, respectively). Regarding the implantation sites, no significant differences were found between the experimental implants and the control group, only the implants placed at P4 level in the experimental group obtained the best result (p=0.041). The linear data obtained from the periapical radiographs indicated greater bone loss in the control group compared to the experimental group (3.2±0.45 and 2.75±0.55 mm, respectively). Conclusions: Despite the better results obtained for the chitosan-coated surface group, further preclinical studies would be necessary to confirm our results.
Purpose: Clopidogrel is a P2Y12 purinergic receptor inhibitor and a widely prescribed antiplatelet drug for the prevention of atherosclerotic events. Accumulated evidence suggests that purinergic receptors regulate important functions in bone healing and homeostasis. The purpose of the present study was to evaluate the effect of continuous perioperative clopidogrel treatment on osseointegration of titanium implants. Materials and Methods: Thirty two white New Zealand rabbits were randomly assigned in two groups: a clopidogrel group and a control group. Rabbits of the clopidogrel group received daily 3mg/kg of clopidogrel and the control group received vehicle for one week prior to the surgical placement of a titanium implant in their medial femoral condyle; treatment was continued for another six weeks postoperative. At this time, postmortem histologic and histomorphometric evaluation of the implants was performed. Results: Surgical procedures and postoperative period were uneventful and well tolerated by all animals without any surgical wound dehiscence, signs of infection or other complication. No implant failure was observed in any of the groups. Histomorphometric analysis showed that BIC (%) was 48.77% for the clopidogrel group and 34.65% for the control group with statistically significant difference between them (P < 0.001). Moreover, clopidogrel group had significantly greater bone tissue density (40.52 % vs 28.74 %, p<0.001) and mean trabecular thickness (284.7 μm vs 180.7 μm, p<0.001) in proximity to the implant surface, while mean trabecular number had no difference between groups (1.56 vs 1.60, p=0.961). Conclusions: The present study showed that continuous clopidogrel treatment does not negatively affect osseointegration, but rather promotes it in terms of BIC and bone density around the titanium implants. Further studies on the effect of the P2Y12 receptor and its antagonists on peri-implant bone homeostasis may provide useful information or applications for long-term success of dental implant therapy.
Aim: This report stems from a homogeneous patient cohort from two similarly designed prospective controlled studies in the same center on surgical reconstructive treatment of peri-implantitis. The aim of this re-analysis study was exploring prognostic factors associated with surgical outcomes. Materials and methods: Individual patient data of both studies were gathered. The initial study employed a submerged healing approach via primary wound closure with implant supra-structure removal and complete coverage of grafted sites. The second study employed a non-submerged healing protocol in which healing abutments were kept in place and the implant was not fully submerged. Both studies measured all outcomes at similar timepoints throughout 1 year, to include clinical and radiographic defect fill (DF and RDF), reduction of pocket depth (PDR) and bleeding on probing (BOP). Multi-level regression was used for statistical assessment of outcomes, relative to the impact of site-/local-, surgical- and patient-related variables. Results: Overall, 59 implants (30 in submerged and 29 in the non-submerged group) were treated. A statistically significant higher DF (on average 0.9 mm higher), RDF (1.7 mm) and PDR (1.3 mm) were observed when a submerged reconstructive approach was performed, whereas BOP reduction was similar. After controlling for treatment (submerged/non-submerged), there were no other significant associations with patient- (age, gender, smoking, prior periodontitis etc.), or implant-related (previous prosthesis type, arch, KTW, etc.) factors. Conclusion: Within its limitations, we conclude that a submerged reconstructive approach for surgical management of peri-implantitis leads to significantly enhanced clinical and radiographic outcomes when compared to a non-submerged approach.
Purpose: Dental implant manufacturers recommend healing abutments (HA) be used for single-patient use; however, reuse on multiple patients following decontamination and sterilization is common. This study aims to evaluate four decontamination strategies utilizing enzymatic agents, available in most clinical settings, to determine the level to which biomaterial can be removed in a group of previously used HA (uHA). Secondly, to determine the degree to which the decontaminated HA are capable of inducing an inflammatory response in-vitro compared to new, never used HA. Materials and Methods: Fifty HA were collected following 2-4 weeks of intraoral use and distributed randomly into 5 test groups (Group A-E; n = 10/group). Group A: Enzymatic cleaner foam + Autoclave; Group B: Ultrasonic bath with enzymatic cleaner + Autoclave; Group C: Prophy jet + Enzymatic cleaner foam + Autoclave; Group D: Prophy jet + ultrasonic bath with enzymatic cleaner + Autoclave; Group E: Prophy jet + Autoclave. Ten new, sterile HA served as controls (Group “Control”). Residual protein concentration was determined by a Micro BCA protein assay while HA from each group were stained with Phloxine B and macroscopically examined for the presence of debris. To examine the inflammatory potential, human primary macrophages were exposed to HA and supernatant levels of 9 cytokines/chemokines profiles were analyzed using a multiplex bead assay. Results: All test groups presented with differences in the degree of visual decontamination compared to Controls, with Groups D and E displaying the most effective surface debris removaland reduced protein concentration. Of the detoxification strategies, Groups D and E removed the greatest biomaterial while least effective was Group A. However, compared to Controls, multiplex assays revealed high levels of inflammatory cytokine secretion up to 5 days from all Test Groups (A-E) irrespective of the decontamination method used. Conclusion: Our study found that compared to new, never used HA, decontamination of uHA utilizing enzymatic cleaners failed to reestablish inert HA surfaces and prevent an inflammatory immune response in-vitro. Clinicians should not reuse HA even after attempts to decontaminate and sterilize HA surfaces.
Purpose: In the clinical setting, assessing bone quality and quantity at the implant site is the basis to select implant characteristics and the insertion protocol to be applied. However, a quantitative method to classify bone quality and quantity is still lacking. A recently introduced implant placement micromotor that provides site-specific, operator-independent cancellous bone density measurements may be useful for this purpose, but it remains unknown whether this device can detect the presence of a cortical bone layer and measure its thickness and density. Materials and Methods: Thus, an in vitro experiment was performed on six double-layer polyurethane foam blocks mimicking the jaw bone with different cortical thickness/cancellous density combinations. The densities were measured using the micromotor, either removing the cortical layer or leaving it intact, with and without irrigation. Results: The results collected in each condition were compared by means of non-parametric statistical tests. Independent of irrigation, the micromotor detected the cortical layer when it was left intact and accurately estimated its thickness. The micromotor did not discriminate each block from the other ones when they were considered separately, but it did when they were grouped into four or three classes. Conclusion: The present study suggested that the micromotor may represent a valid device to quantitatively assess bone quality and density. If the micromotor can quantitatively distinguish different cortical/cancellous bone combinations in humans, it may be a helpful tool to define finely-tuned, patient-tailored preparations of the implant seat, making teeth rehabilitation in challenging clinical conditions more predictable.
This study aimed assessed the pain, swelling, infection, and alteration in sensation, following the flapless placement of zygomatic implants guided by dynamic navigation. A randomized controlled trial was conducted on 20 patients. In Group 1, the placement of the zygomatic implants was carried out without reflecting a mucoperiosteal flap (flapless), and in Group 2 a mucoperiosteal flap was raised (flapped). In each patient, two zygomatic implants were placed (one on each side) under local anaesthesia, guided by dynamic navigation. Postoperative evaluations included pain (using the visual analogue scale), swelling (using standard measurements), maxillary sinus infection, and alteration of sensation (using mechanical stimuli, thermal threshold detection, and a two-point discrimination test). The assessments were carried out at two days, one week, and then one, two and three months, postoperatively. The implants successfully osseointegrated, except one, in Group 1. Immediate postoperative pain and swelling were both significantly greater in Group 2 (p < 0.01). No alteration in sensation was detected in any case in the two groups. There were three cases of chronic sinusitis: one in the Group 1 and two in Group 2. The flapless placement of zygomatic implants, under local anaesthesia, guided by dynamic navigation, improves postoperative recovery.
DOI: 10.11607/jomi.10490, PubMed-ID: 379108361. Nov. 2023, Sprache: EnglischVan den Borre, Casper / De Neef, Björn / Loomans, Natalie A. J. / Rinaldi, Marco / Nout, Erik / Bouvry, Peter / Naert, Ignace / Van Stralen, Karlijn J. / Mommaerts, Maurice Y.
Purpose: There are few treatment options for oral rehabilitation in patients with advanced maxillary resorption (Cawood-Howell Class V or more). Patient-specific, 3D-printed titanium subperiosteal implants have been described as a potentially valuable alternative solution. Surgeon and patient mediated functional outcomes have been studied and the results are promising. The surrounding soft tissue health has been much less researched. This study aims to evaluate the soft tissue response to the placement of additively manufactured subperiosteal jaw implants (AMSJI®) in the severely atrophic maxilla and to identify possible risk factors for soft tissue breakdown. Materials and methods: An international multicenter study was conducted and fifteen men (mean age 64.62 years, SD ± 6.75) and twenty-five women (mean age 65.24 years, SD ± 6.77) with advanced maxillary jaw resorption (Cawood-Howell Class V or more) were included in this study. General patient data were collected and all subjects were clinically examined. Inclusion criteria were patients who underwent bilateral AMSJI placement® in the maxilla at least a year before and whose surgeon and themselves agreed to participate in the study before their inclusion. Results: A total of forty patients were enrolled with a mean follow-up period of 917 days (SD ± 306.89 days). Primary stability of the implant was achieved postoperatively in all cases, and all implants were loaded with a final prosthesis. At the time of study, only one patient showed mobility of the bilateral AMSJI (more than 1 mm). Exposure of the framework, due to mucosal recession, was seen in 26 patients (65%) and was mainly in the left (21.43%) and right (18.57%) mid-lateral region. Thin biotype and the presence of mucositis were found to be risk factors (p-value < 0.05). Although not significant, smokers had a nearly seven times (Odds ratio 6.88, p=0.08) more risk of developing a recession compared to nonsmokers. Conclusion: Twenty-six (65%) patients presented with a recession in one or (more) of the seven regions after oral rehabilitation with bilateral AMSJI installation. Several risk drivers were evaluated. The collapse of soft tissues around the AMSJI that led to caudal exposure of the arms was correlated with a thin biotype and the presence of mucositis.
Purpose: Reconstruction of atrophied mandible using ridge splitting technique is a challenging procedure. In the present study we demonstrate a modified surgical approach for horizontal ridge augmentation. The technique allows safe manipulation and predictable management of the buccal plate, and avoids secondary surgical site. Materials and Methods: This pilot randomized controlled clinical trial included 24 patients requiring horizontal alveolar ridge augmentation. Patients were assigned to one of the three groups. Group A was treated with the buccal plate repositioning technique (BPR) technique and grafted with silica-calcium-phosphate nanocomposite (SCPC) graft. Group B was similarly managed and grafted using freeze-dried bone-allograft (FDBA). While group C was augmented using mandibular ramus autogenous bone block graft (ABBG). The primary outcome was the coronal crest width measured at 6 months using CBCT. Results: BRT resulted in horizontal augmentation of a mean (4.30mm ± 0.94) for the SCPC group, showing no significant difference to either of the allograft group (4.98mm ± 1.13), or the ABBG group (3.68mm ± 0.27). All augmented ridges allowed for successful implant placement with good primary stability. Conclusion: The BPR technique resulted in horizontal bone gain in extremely narrow alveolar ridge. It allowed implant placement in a vascular cancellous bed protected by intact cortical plate. Different types of bone grafts whether alloplast or allograft, resulted in successful augmentation comparable to that gained from autogenous block grafting.
Introduction: Different surgical procedures have been proposed to achieve successful horizontal ridge reconstruction of the anterior maxilla, most of these procedures require complex surgical stages with morbidity and are time-consuming. Aim: The purpose of this study is to evaluate the efficacy of using a customized xenograft shell with a 1:1 mixture of particulates xenograft and autogenous bone for the reconstruction of horizontally deficient anterior maxillary alveolar ridges. Methods: Cone beam computed tomography (CBCT) images of the atrophic maxilla of eight patients were acquired and generated into 3D models. The data were transferred to a 3D printer and solid models were fabricated. During the surgery, the xenograft blocks were manually sliced and customized on the 3D printed models and fixed then the gap was augmented with a 1:1 xenograft autograft mixture. Results: Clinical assessment showed no adverse effects. However, one patient exhibited wound dehiscence. The mean difference between the preoperative and the six months postoperative showed a net average bone gain by 4.06 mm at 2 mm from the crest and 4.34 mm at 5 mm from the crest, which was statistically significant. On the other hand, a statistically significant graft resorption by 1.41 mm and 2.19 mm at 2 and 5 mm from the crest was found when the mean difference between the immediate and the six months postoperative was calculated. Conclusions: Within the limitations of the study, the use of xenograft shells as a barrier for maxillary alveolar ridge reconstruction is predictable technique however, further investigations regarding the required time for graft consolidation is required.
Purpose: This randomized controlled trial (RCT) aimed to compare treatment time of single-implant crowns for both digital and conventional workflows. In addition, prostheses made of polymer-infiltrated ceramic-network (PICN; Enamic®, Vita, Bad Säckingen, Germany) and lithium disilicate (LS2; NICE®, Straumann AG, Basel, Switzerland) were compared in each group. Materials and Methods: A total of 40 patients (n=40) who needed a single-implant crown on posterior regions were considered and randomly divided into digital workflows (n=20) with an intraoral scanner (IOS, iTero Elements 5D®, Align Technologies, San José, CA, USA) and conventional workflows (n=20) with impressions using polyether (Impregum™ Penta™, 3M ESPE, Landsberg am Lech, Germany). Then, each group was again distributed into 2 subgroups based on the crown materials used: PICN (n=10) and LS2 (n=10). Treatment time was calculated for both digital and conventional workflows. Analysis was done at 5% confidence interval (p-value <0.05). An independent two-sample t-test was used to compare treatment time between the groups. The Kruskal–Wallis test was used to compare clinical try-in time among sub-groups. Any of the implant crowns that had to be remade in each subgroup, were evaluated by the Fisher Exact test. Results: The entire process of digital and conventional workflows required 104.31 ± 20.83 minutes and 153.48 ± 16.35 minutes, respectively. Digital workflows were 39.2% more timesaving than the conventional protocol for the implant single crown treatment (p <0.0001). Conclusions: Both digital and conventional workflow protocols can achieve a successful outcome of single-implant monolithic crowns in posterior areas. The digital protocol yielded a greater time saving over the conventional procedure in data acquisition and laboratory steps while the time for a clinical try-in and delivery were similar.
Dental implants are an established treatment options for varying edentulous conditions and has grown in popularity since the 1990’s. This increased clinical application has evidenced a parallel increase in dental implant related research. The objective of this paper was to perform a comprehensive bibliometric analysis of five dental implantology journals from 1991-2023. Materials and Methods: We performed a search in the ISI Web of Science database between 1991 and 2023 in 5 journals with a focus on dental implantology: Clinical Oral Implant Research, Clinical Implant Dentistry and Related Research, Implant Dentistry, International Journal of Oral and Maxillofacial Implants, and International Journal of Oral Implantology. Results marked as correction, retraction notices, retracted articles, meeting abstract, withdrawn publications were removed from the analysis. The time period analyzed was divided into 4 decades: 1991-2000, 2001-2010, 2011-2020, 2021-2023. Additionally, the top 100 cited papers were also exported separately. Authors and countries with most publications were tabulated from the Web of Science database. VOS Viewer software was used to create network maps of keywords and title word occurrences for each of the time periods. Histcite software was used to analyze number of publications and citation counts. Results: Network maps of keywords and title word occurrences suggested an early focus on osseointegration and titanium implants between 1991-2000. Publications between 2001-2010 saw a focus on in-vivo studies, implant surface and peri-implantitis. Publications post 2011 saw a focus on bone regeneration, complications and zygomatic implants. USA ranked highest in total number of publications in all time periods analyzed. Conclusions: Within the limitations of the study, we reported a comprehensive bibliometric analysis from 1990-2023. We identified trends in keywords and titles of dental implant publications in these journals which mirrored the trends seen in clinical practice.
Purpose. The purpose of this study is to compare the factors of taper, length, angle and number of vertical axial walls that affect the retentive strength of a cemented crown on a partially customizedhybrid abutment in the esthetic zone. Materials and Method. A total of 35 metal copings were used in this study divided into one group with 30 copings cemented to their corresponding 8° tapered abutment with lengths from 3 to 8 mm with 1 mm increments. The remaining five consisted of a standardized metal coping matching a hexagonal abutment with 3 mm vertical axial walls and the sequential removal of 1, 2, and 3 contiguous vertical axial walls. Dislodgment tests were performed for all copings in both groups. Maximum retentive forces were measured in kgF with a conversion factor of 9.807 N to 1 kgF. Results. At each tapered abutment length, the retentive strength increased proportionally and was significantly different from 31.67 ± SD 4.10 kgF to 67.68 ± SD 11.22 kgF, respectively [F (5,24) =20.46, p < 0.001]. An unmodified hexagonal abutment demonstrated the highest retentive strength of 70.15 ± SD 12.97 kgF. Sequential removal of 1, 2, and 3 contiguous vertical axial walls of the hexagonal abutment was 59.89 ± SD 10.06 kgF, 57.01 ± SD 9.62 kgF, and 55.99 ± SD 9.35 kgF, respectively with no significant difference (p > 0.05) in retentive strength. Conclusion. A partially customized abutment with vertical axial walls on one side and a profile reduction on the opposite side can provide comparable retention of cemented copings at 1/3 the length and 1/6 the surface area of an 8 mm high abutment with an 8° taper.
Purpose: The structural and compositional similarities between dentin and alveolar bone formed the basis for utilizing dentin for bone regeneration. Various authors recommended using treated mineralized, partially demineralized, and demineralized dentin grafts over xenografts because of their comparable clinical and radiographic results and lower costs. Therefore, the current study aimed at comparing the effect of untreated mineralized dentin grafts (UMDG) versus xenografts in vertical and horizontal augmentation around dental implants that were immediately placed in the mandibular anterior region. Materials and methods: A total of 56 patients who required immediate dental implant placement in the lower anterior region were randomly allocated to group I (study), where ground dentin was washed with normal saline and placed around the dental implants, and to group II (control), where xenograft was used. The primary implant stability was measured at the time of implant placement. Secondary stability, plaque index (PI), bleeding index (BI), probing depth (PD), and keratinized mucosa width (KMW) were assessed at baseline (time of definitive abutment and temporary crown placement) and then at 3, 6, and 12 months. Pain and the number of analgesics consumed were assessed daily during the first postoperative week. Marginal bone loss (MBL) and radiodensity were assessed radiographically. Results: There were no significant differences between both groups in terms of postoperative pain, the number of analgesic tablets consumed, peri-implant mucositis, or peri-implantitis. Both groups showed comparable results for the PI, BI, and BD. Moreover, there was no statistical difference between both groups with regard to primary implant stability and secondary stability at baseline and 12 months. Group I showed significantly lower secondary stability after loading at 3 and 6 months and significantly greater bone loss and lower bone density before exposure. KMW and MBL after exposure were significantly higher in group I at all time points. Conclusion: Although UMDG showed similar clinical results as xenografts, including primary and secondary implant stability, they had higher resorption rates than xenografts. Therefore, treatment of the dentin graft is required. Thus, the authors do not recommend using untreated mineralized dentin grafts.
Purpose: To quantify the clinical accuracy of a robotically assisted implant guidance system in partially edentulous patients without the use of postoperative cone-beam radiography. Materials and Methods: A total of 10 implants (7 patients) were placed in partially edentulous patients utilizing robotically assisted implant guidance system. Following the implant placement a intraoral scan was performed to register the implant position after attaching a scan body. The virtual plan and the postoperative intraoral scan with the scan bodies were exported as STL files, superimposed and discrepancies were analyzed using Geomagic Control X software. Positional deviations were measured between the midpoint of the platform and apex of the planned and achieved implant positions. Results: Seven of the 10 samples in this study were defined as fully robotically dynamically guided, while 3 were partially robotically guided. For the fully robotic dynamically guided group the mean deviation at the midpoint of the restorative platform of the implant, the apex of the implant, the top of the scanbody, and the mean angular deviation were 1.31mm (SD0.46mm), 1.58mm (SD0.61mm), 1.11mm (SD0.57mm), and 2.34 degrees (SD1.71º), respectively. While for the partially robotic dynamically guided cases it was 1.31mm (SD0.49mm), 1.45mm (SD0.3mm), 1.74mm (SD0.47mm), and 3.75 degrees (SD2.53º). Eight out of the 10 implants (irrespective of full or partial guidance) showed a buccal displacement. Conclusion: Robotic surgery offers a level of accuracy similar to fully guided implant placement, without the need for a physical template, and allowing for changes in the surgical plan at any time. The analytical method described in this study is an effective and radiation free quality control tool that can be used in implant dentistry as well as in other areas of dental research dentistry.
Purpose: The purpose of the study is to investigate the screw loosening and fracture resistance of different hybrid abutment crown restorations after thermomechanical aging. Materials and Methods: Restorations were produced from zirconia, lithium disilicate, and hybrid ceramics with CAD-CAM system (n=10). Restorations and titanium bases (Tibases) were cemented and the abutment screws were torqued to 30 Ncm. They were retorqued after 10 minutes, and removal torque values (RTV) were measured. When 250000 and 500000 cycles of thermomechanical aging were completed, the RTVs were measured again and removal torque loss (RTL) ratios were calculated. The specimens were subjected to fracture resistance test after 750000 cycles of thermomechanical aging. The load at failure was recorded as the fracture resistance (N). The results were statistically analyzed (α=0.05). Results: Aging was effective on the RTVs and RTL ratios (P<0.001). The highest RTV was observed before aging; however, the RTVs significantly decreased and RTL ratios significantly increased after aging (P<0.05). The fracture resistance values significantly differed among the ceramic materials. All lithium disilicate and hybrid ceramic specimens showed restoration fracture, while most of the zirconia specimens were displayed Tibase related failure. Conclusion: Hybrid abutment crowns made of zirconia, lithium disilicate, and hybrid ceramics can withstand the average occlusal forces in the molar region; however ceramic type may affect the failure type. Retightening of the abutment screws after 10 minutes after first tightening and annually may be beneficial to prevent the adverse effects of screw loosening on the integrity of implant-abutment connection.
Purpose: Dental implants are a common method for the treatment of tooth loss, and its accuracy directly affects forward efficacy and stability. This study compared the accuracy of different modalities of dental implant placement (dynamic navigation [DN], fully guided [FG] static navigation, partially guided [PG] static navigation, and free handed [FH]) through a network meta-analysis. Materials and Methods: This study followed the Preferred Reporting Items for Meta-Analyses (PRISMA) guidelines and conducted an electronic literature search (Inception-Oct 2, 2022). The comparison of implant accuracy in all the included randomized controlled trials (RCTs) conformed to at least one of the following: deviation at the crown of the implant, deviation at the apical portion of the implant, or angular deviation of the implant. Results: Twenty-six articles were included for the qualitative analysis (17 RCTs; 3 prospective studies; 6 retrospective studies), and 17 RCTs of which were included for network meta-analysis. The data included in this study had high consistency, and the funnel plot showed that the articles had low publication bias. Compared with FH, FG and DN had higher accuracy in coronal deviation (P<0.05), and FG, DN, and PG had higher accuracy in apical deviation and angular deviation (P<0.05). According to the SUCRA value, FG had the highest accuracy in coronal deviation, while DN had the highest accuracy in apical deviation and angular deviation. Conclusions: According to the results of this literature review, the accuracy of DN, FG, and PG were higher than those of FH. DN showed the highest accuracy in terms of apical deviation and angular deviation. FG had the best control over the coronal deviation. There was no statistical difference between DN and FG in terms of accuracy. Given the limitations of the current study, further validation is required in the future.
Purpose: The primary aim of this study is to evaluate the correspondence between an Artificial Intelligence driven new tool prediction and the clinician’s evaluation in the immediate loading suitability of curves recorded during implant insertion in an in vitro test. The secondary aim is to analyse peak insertion torque (pIT) and variable torque work (VTW) values of the implants used for the in vitro study. Material and methods: The study was performed on artificial bone blocks of solid rigid polyurethane without cortical layer with four different densities. Five types of implants with different macrogeometries were used. A total of 140 implants (7 implants of each type in the four polyurethane blocks) were inserted. Immediately after implant placement the insertion curves were classified by the operator as suitable or non-suitable for immediate loading. In a second moment the same curves were analyzed by the new AIT that classified them as belonging to YES or NO class. For each implant pIT and VTW were also recorded. Results: The correspondence between surgeon and AIT evaluation was 99,3% with only one false-negative reported by the algorithm analysis. The sensitivity resulted 98.95%, the specificity 100%, positive predictive value 100% and negative predictive value 97.8%. Mean pIT of the whole sample was 34.19 + 19.43 Ncm while mean VTW was 2266.89 + 1993.73 Ncm. Statistically significant differences were found between implant systems in the whole sample and when divided by polyurethane block density. Conclusions: AIT showed a high level of accuracy in the prediction of immediate loading suitability of insertion curves examined. All the implants used in the in vitro test were able to reach good levels of primary stability, excluding when inserted in the less dense polyurethane block. Clinical studies conducted in larger samples and with more surgeons involved are necessary to confirm these results.
Purpose: The aim of this study was to investigate the effects of membrane stabilization by suturing the sinus membrane and dental implant insertion on endo-sinus bone formation in lateral sinus lifting performed without grafting. Materials and Methods: Maxillary sinus lift surgery using the lateral approach was performed bilaterally in 30 New Zealand white rabbits. The maxillary sinus areas were divided into control and test groups. In the control group, a titanium screw was placed after sinus membrane elevation, while in the test group, the sinus membrane was sutured to the lateral walls and a titanium screw was placed in the center of the alveolar crest. The animals were sacrificed at 4 and 8 weeks. Samples were collected, and micro-computed tomography (micro-CT) analysis was performed. The volume of newly formed bone, percentage of osseointegration, sinus volume, residual bone height, and protrusion length of the implants were measured using micro-CT analysis. Results: The sinus volume, volume of newly formed bone, and percentage of osseointegration in the test group were significantly higher than those in the control group at 4 weeks (p = 0.01, p = 0.04, p = 0.02, respectively) While the volume of newly formed bone was 17.1 ± 3.08 mm3 in the control group, it was 26.9 ± 14.26 mm3 in the test group at 4 weeks. The volume of newly formed bone was significantly decreased from 26.9 ± 14.26 mm3 to 17 ± 3.66 mm3 at 8 weeks (p = 0.02). No significant difference in residual bone height was found at 4 and 8 weeks (p = 0.07). No significant difference in implant protrusion length was found between the control and test groups (p = 0.18). Protrusion length and new bone formation in the sinus showed a negative relationship (p = 0.01). Conclusion: Suturing the sinus membrane to the lateral sinus wall is an effective approach for increasing osseointegration, bone volume, and sinus volume in the short-term. A slow-absorbing suture material can be used to maintain sinus and bone volumes in the long-term.
Purpose: The aims of the study were to evaluate the clinical performance and the complications of combined tooth-implant supported 3 unit fixed partial dentures in the posterior mandible. Materials and methods: 78 partially edentulous patients in the posterior mandible were recruited for the study (n=26/group). Group 1 served as the control group and received 2 dental implants for supporting 3 unit fixed partial dentures (FPD). Groups 2 and 3 were the experimental groups where an implant was combined with a tooth. As stated by the dental implant company, standard implants (8 mm or longer) were included in Group 2, while short implants (shorter than 8 mm) were included in Group 3. Periapical radiographs were taken for evaluation of marginal bone resorption (CBL). Modified plaque index (MPI), bleeding index (BI) and sulcus depth of abutment teeth was recorded at the time of FPD insertion, 6 months after FPD insertion and annually. Abutment tooth intrusions, cementation failures of the restorations, porcelain chipping/delamination, framework fracture, abutment screw loosening, abutment and abutment screw fracture, implant fracture were also recorded as complications. Results: Statistically significant different was observed between group 1 (.06 .17) and group 2 (.18 .32) and group 1 and group 3 (.17 .30) in terms of MPI (p≤0.05). No difference was observed between group 2 (.11 .34) and group 3(.14 .36) and group 1(.04 .22) and group 2 in terms of BI. There was statistically significant difference in terms of CBL between group 1 (.259 .05 mm) and group 3 (.11 .03 mm), and group 2 (.03 .03 mm) and group 3 (p≤0.05).The mean abutment tooth sulcus depth was 1.11 .31 mm for group 2 and 1.20 .46 mm for group 3. Conclusion: Within the limitations of the current study, it was concluded that combined tooth-implant supported prostheses (CTISP) is a predictable treatment choice in posterior mandible. When CTISP is planned, it is more predictable to use short dental implant rather than a standard-length dental implant.
Purpose: To examine the stresses caused by different All-on-4 surgical techniques—conventional, a combination of monocortical and bicortical, bicortical, and nasal floor elevation—on the implant and the surrounding bone using 3D finite element analysis (FEA). Materials and Methods: A 3D bone model of the atrophic maxilla was created based on CT imaging of the fully edentulous adult patient. All implants used in the models were 4 mm in diameter, and the length was 13 mm in the anterior and 15 mm in the posterior. Implants were applied to four different atrophic maxillary models with the All-on-4 technique: anterior and posterior monocortical implants in the first model, anterior monocortical and posterior bicortical in the second model, anterior and posterior bicortical in the third model, and anterior and posterior bicortical with nasal floor elevation in the fourth model. Eight linear analyses were performed by applying force from both vertical and 45-degree oblique directions to the four models prepared in our study. Results: When the cortical and cancellous bone around the anterior implants was examined, it was observed that the oblique and vertical loading conditions and the stresses around the implant were similar in all models. When the posterior implants were examined, model 1 (ie, anterior and posterior monocortical implants) showed the greatest oblique compression, vertical compression, and vertical tension forces. According to the Von Mises stress (VMS) analysis results for anterior and posterior implants, higher values were observed in model 1 compared to models 3 and 4 under oblique and vertical forces. It was observed that bicortical placement of the implants reduced the stresses on the bone and implant-abutment system but had no significant effect on the stress on the bar. Conclusions: According to the results of our study, in the All-on-4 technique, bicortical placement of the implants reduced the stresses on the bone and implant when the anatomical limitations allowed. In addition, nasal floor elevation can be applied in the atrophic maxilla in appropriate indications.
Purpose: To assess the peri-implant and flap parameters of the prefabricated microvascular fibula flap and determine the dental implant survival rate. Materials and Methods: This retrospective study investigated a cohort of subjects who received prefabricated microvascular fibula flaps at two highly specialized tumor reconstruction centers. The subjects had all suffered atrophy or a large segmental defect of the jaws due to tumor resection or injury. Two independent surgeons determined the dental implant survival rate and assessed the peri-implant parameters and flap parameters during clinical follow-up. Results: In total, 41 subjects were treated with a prefabricated fibula flap between 1999 and 2012. Of these, 17 subjects (10 male, 7 female) with a total of 62 dental implants were examined. The other 24 subjects were unavailable for assessment and had to be excluded. Ten of the 62 dental implants (16.1%) had to be removed due to peri-implantitis before the follow-up assessment. Follow-up assessments were performed at intervals ranging from 2 to 12 years (mean: 7.2 years) after fibula flap transplantation. The dental implant survival rate was found to be 83.9%. A total of 208 dental surfaces were assessed. Overall, 96% of all surfaces had a pocket depth (PD) of ≤ 4 mm and 4% had a pocket depth of > 5 mm. An attachment level (AL) of 3 mm was measured in 48.5% of implants and ≥ 5 mm was measured in 15.9% of implants. Dental implants with a PD > 4 mm showed a significantly higher plaque index (PI) (75%; P = .0057), papillary bleeding index (PBI) (62.5%; P = .0094), and radiologic bone loss (P = .0014) compared to dental implants with a PD ≤ 4 mm. Conclusions: Reconstructive surgery using microvascular fibula flaps represents an alternative tool for oral rehabilitation in subjects suffering from a large segmental defect in the maxillary or mandibular bone compared to the conventional method. However, it appears that the different ossification processes that develop the fibula and the jawbones affect dental implant survival.
Purpose: To compare the standard 360-degree CBCT acquisition protocol to the low dose 180-degree CBCT protocol for implant planning.
Materials and methods: Two groups of patients, each consisting of 35 patients, were included in the study. The first group was imaged with the conventional 360-degree CBCT protocol, and the second group was imaged with the low dose 180-degree CBCT protocol. The primary outcome of this study was the number of scans that needed to be repeated due to poor image quality. In addition, six secondary parameters were evaluated quantitatively and qualitatively.
Results: The results showed that there was no need to repeat any of the CBCT scans that were obtained in either group, which showed that 360-degree and 180-degree protocols had comparable image quality. As for the secondary parameters, the results showed that the evaluators were able to evaluate the six chosen parameters in a comparable manner.
Conclusion: The 180-degree low dose CBCT scan is a viable option for dental implant treatment planning in the posterior mandible as it provides comparable and adequate information regarding accuracy of measurements, identification of critical structures, evaluation of bone quality, and any pathology.
Schlagwörter: CBCT, implant planning, 180-degree, dental implant, ALARA, radiation, low-dose radiation, radiology
Purpose: To examine the changes of dentoalveolar structures and pathologies in the maxillary sinus before and after dental implant surgery alone or with direct vs indirect sinus lifting using CBCT images of the maxillary posterior region. Materials and Methods: Preoperative and postoperative CBCT images of 50 sinus sites and the alveolar bone around 83 implants in 28 patients were evaluated. Maxillary sinus pathologies were classified as mucosal thickening (MT), mucus retention cyst (MRC), polyp, and sinusitis before and after surgery. The changes after surgery were determined to be no change, reduction in pathology, or increase in pathology. Comparisons of pathology changes among the treatment groups were evaluated statistically with chi-square test, McNemar test, and Mann-Whitney U test. Results: Of the 50 sinuses evaluated for the presence of sinus pathology, 24 of 50 did not change postoperatively, the pathology increased in 10 sinuses, and the pathology decreased in 16. When the maxillary sinus regions were evaluated after indirect sinus lifting, direct sinus lifting, and in patients who had only implant surgery, there was no statistically significant difference between pathology distribution in terms of the procedure applied to the sinus (P > .05). However, in the maxillary sinuses with a pathology before implant placement were evaluated postoperatively, a statistically significant difference was found in favor of the presence of a change in pathology (ie, improvement or a decrease; P < .05). The maxillary sinuses without pathology before implant placement showed a statistically significant difference for no change; ie, continuation of the healthy state (P < .05). Conclusion: This study showed that surgical procedures could have a direct effect on the sinus membrane and maxillary sinus. Both the implant procedure and surgical approach may have an effect on maxillary sinus pathology, as well as an increase or decrease of the pathology. Hence, further studies with a longer-term follow-up should be performed to better understand the correlation between implant surgery and pathology.