DOI: 10.11607/jomi.2022.6.ePages 1093, Language: English
DOI: 10.11607/jomi.10210Pages 1095-1099, Language: English
When a clinician sees a patient with a complication, they often go through a Bayesian style of logic, most likely without even knowing it. They assess whether they have seen the complication before, provide an intervention based on historical knowledge of what leads to improvement, and then later assess how the intervention is performed. This process, which is routine in clinical practice, can be mathematically extended into an alternative way of performing statistical analyses to assess clinical research. However, this process is contrary to the most common statistical methods used in dental research: frequentist statistics. Though powerful, frequentist methods come with advantages and disadvantages. Bayesian statistics are an alternative method, one that mirrors how we as researchers think and process new information. In this primer, a walkthrough of Bayesian statistics is performed by constructing priors, defining the likelihood, and using the posterior result to draw conclusions on parameters of interest. The motivating example for this walkthrough was a Bayesian analog to logistic regression, fit using a simulated dental-related dataset of 50 patients who received a dental implant—classified as either within or outside normal limits—from practitioners who did or did not receive a training course in implant placement. The results of the Bayesian and traditional frequentist logistic regression models were compared, resulting in very similar conclusions regarding which parameters seemed to be strongly associated with the outcome.
DOI: 10.11607/jomi.9756Pages 1100-1109, Language: English
Purpose: To systematically measure the survival rate of implants placed pre- and post-radiotherapy.
Materials and Methods: After performing a systematic literature exploration of 10 databases, observational and quasi-experimental studies and case series estimating the survival of dental implants in patients with head and neck cancer placed before, after, and without radiotherapy were included, with no limit on language or year of publication. The Joanna Briggs Institute Critical Appraisal was used to assess the risk of bias in eligible studies.
Results: During the first screening phase, 3,445 studies were found, among which 16 met the inclusion criteria. The median follow-up period was 60 months (range: 1 to 168 months). Seven (43.7%) articles had a moderate risk of bias, four (25%) had a high risk of bias, and five (31.3%) had a low risk of bias. The survival rate for post-radiotherapy, pre-radiotherapy, and without-radiotherapy implants was 80% to 100%, 89.4% to 97%, and 92.2% to 100%, respectively.
Conclusion: Despite the alterations caused by ionizing radiation in peri-implant tissues, dental implants placed pre- and post-radiotherapy had high survival rates, similar to those placed without radiotherapy, which helps improve the condition of life of patients with head and neck cancer.
Keywords: dental implant, survival rate, head and neck cancer, radiotherapy, systematic review
DOI: 10.11607/jomi.9656Pages 1110-1118, Language: English
Purpose: To evaluate an alternative cutting, progressive thread design to increase primary stability in low-density bone.
Materials and Methods: Four different implants with different macrogeometries (Nobel Biocare Active [NA] Internal RP implants [4.3 × 11.5 mm], Straumann BLX Roxolid RB implants [4.5 × 10 mm], Astra Tech Implant EV implants [4.2 × 11 mm], and PrimeTaper [PT 4.2 × 11 mm]) were placed in simulated osteotomies and extraction sockets in synthetic bone (Sawbones) according to the manufacturers’ protocol. Insertion torque and ISQ values were measured using Implantmed Plus motor and Ostell IDX, respectively. Insertion time was recorded. Average values were calculated and compared using ANOVA and Tukey test.
Results: Insertion torque (range: 5 to 44 Ncm) increased with increasing synthetic bone density for all implants. Different ISQ values in synthetic low-density bone were not observed in higher-density synthetic bone. Insertion torque of all implants was reduced when implants were placed in simulated sockets compared to simulated osteotomies. In both low-density and higher-density synthetic bone, the primary stability of PrimeTaper implants with cutting and progressive thread design was equivalent to that of the Nobel Biocare NobelActive implant with compressive thread design and greater than the BLX implant with compressive thread design.
Conclusion: Different implant macrogeometries obtain relatively high primary stability in low-density bone when measured by ISQ. Doublethread implant designs reduce insertion times in higher-density bone. A cutting and progressive compressing thread design provides density-sensing performance compared to aggressive condensing thread designs. This macrogeometry can achieve high primary stability associated with modest insertion torque compared to aggressive threaded implant designs known to attain the highest insertion torque. The presence of multiple cutting threads may offer advantages in obtaining primary stability in low-density bone.
Keywords: dental implant, in vitro, insertion torque, macrogeometry, primary stability
DOI: 10.11607/jomi.9635Pages 1119-1137, Language: English
Purpose: To summarize the evidence and determine the most effective impression technique for implant-supported prostheses in terms of accuracy, time efficiency, and patient preference in partially and completely edentulous arches.
Materials and Methods: The searches were performed independently up to April 30, 2021 by two review authors through the Cochrane Oral Health Review, MEDLINE/PubMed, LILACS, and Science Direct databases. Moreover, manual and gray literature searches were performed to identify further potential reviews. Only English language–based systematic reviews with and without meta-analyses evaluating the different dental implant impression techniques were included. The outcomes assessed were accuracy, time efficiency, and patient preference. The methodologic quality of the included reviews was investigated by using the R-AMSTAR tool, and the degree of overlap of primary studies was assessed by calculating the percentage of corrected covered area (CCA) as proposed by Pieper et al.64
Results: The qualitative analysis included a total of 28 reviews, 8 of which included meta-analyses, published between 2008 and 2021, involving a total of 42 clinical trials and 203 laboratory studies. Digital vs conventional implant impression techniques were compared in 17 reviews, different digital impressions in 3 reviews, and different conventional impression techniques in the remaining reviews. Overall, the methodologic quality assessed by using the R-AMSTAR tool was moderate (mean: 26.7 ± 5.5) with slight overlap of primary studies (CCA; 5.23%).
Conclusion: Within an overall moderate methodologic quality, the digital implant impressions showed favorable outcomes in terms of accuracy, time efficiency, and patient preference in partially edentulous arches involving three or fewer implants. However, the accuracy of full-arch digital impressions involving multiple implants is not satisfactory and needs significant improvements. Hence, future studies following stringent guidelines and robust methodology are recommended to substantiate the findings of this overview and provide a high level of evidence.
Keywords: accuracy, conventional implant impression, digital implant impression, evidence-based dentistry, implant, overlap, patient preference, tertiary research, systematic review, R-AMSTAR
DOI: 10.11607/jomi.9692Pages 1138-1144, Language: English
Purpose: To compare the clinical outcomes of autogenous and allogeneic demineralized dentin matrices loaded with recombinant human bone morphogenetic protein-2 (rhBMP-2; auto- and allo-DDM/rhBMP-2) by measuring the buccal marginal bone resorption around dental implants.
Materials and Methods: This retrospective study included patients who underwent dental implant placement with auto-DDM/rhBMP-2 as the control group and allo-DDM/rhBMP-2 as the experimental group. The primary outcome was buccal marginal bone resorption on CBCT. The resorption was calculated during T0 (from surgery to prosthetic loading), T1 (during the first year after loading), and T2 (during the second year after loading). The secondary outcome was the histologic analysis of five specimens of each group, obtained during the prosthetic procedure.
Results: Among the 103 implants, 61 and 42 implants were placed with auto- and allo-DDM/rhBMP-2 matrices, respectively. The resorptions of all periods were similar between the groups (T0: 0.65 ± 0.71 and 0.67 ± 0.81 mm, T1: 0.55 ± 0.60 and 0.59 ± 0.81 mm, and T2: 0.29 ± 0.45 and 0.20 ± 0.30 mm with auto- and allo-DDM/rhBMP-2, respectively). The histologic and histomorphometric analysis revealed similar osteoinductive aspects and proportions of new bone between the groups.
Conclusion: Allo-DDM/rhBMP-2 showed comparable outcomes in terms of buccal marginal bone resorption to auto-DDM/rhBMP-2 during the second year after loading.
Keywords: allogeneic, bone substitutes, demineralized dentin matrix, dental implant, rhBMP-2
DOI: 10.11607/jomi.9629Pages 1145-1150, Language: English
Purpose: To investigate the effects of injectable platelet-rich fibrin (i-PRF) on implant stability.
Materials and Methods: A total of 40 implants (BEGO Semados RS/RSX implants, BEGO Implant System) were surgically placed in 15 patients between the ages of 25 and 67 years who had mandibular edentulous areas. After the implant sockets were prepared with the appropriate protocol, i-PRF was applied to the implant surface and socket with the help of a 5-cc sterile syringe in the study group, and implants were placed without i-PRF in the control group. In the research process, the resonance frequency analysis (RFA) method was used to measure implant stability. The implant stability quotient (ISQ) values were determined during the time of the operation and at the first, second, and fourth weeks.
Results: The results obtained after the stability measurement periods showed that the decrease in the mean ISQ values in the control group was statistically significant in the first week. Evaluations made in the following weeks were not statistically significant. The study group showed an increase in ISQ values during the measurement periods, and the increases in the second and fourth weeks were statistically significant.
Conclusion: I-PRF had positive effects on early implant stability, and i-PRF can be safely used in dental implant surgery and promotes bone healing around dental implants.
Keywords: injectable platelet-rich fibrin, primary implant stability, resonance frequency analysis
DOI: 10.11607/jomi.9626Pages 1151-1159, Language: English
Purpose: To evaluate the effects of ultraviolet (UV) treatment and alendronate immersion on the osseointegration of dental implants and mucosal attachment of dental implant abutments using a mongrel dog model.
Materials and Methods: A total of 48 sandblasted, large-grit, acid-etched (SLA) titanium dental implants and 48 machined surface healing abutments in four male mongrel dogs were prepared. Implants and healing abutments were divided into four groups (n = 12 per group). The control (CON) group did not undergo additional surface treatments. The UV group was treated with UV for 15 minutes, and the alendronate-immersed (AN) group was soaked in 10–3 M alendronate for 24 hours. The UV treatment and alendronate soaking (UVAN) group was treated with alendronate, followed by UV irradiation. All implants were placed in the mandible of mongrel dogs, and the animals were sacrificed at 4 and 8 weeks postoperatively. Bone-to-implant contact (BIC), bone density, and connective tissue attachment were measured.
Results: In cortical bone, the UV group exhibited significantly higher BIC compared to the CON and AN groups (P < .05). In contrast, the AN and UVAN groups did not have significantly higher BIC. In the trabecular bone, there was no statistical difference between the groups. No significant increase in bone density and connective tissue attachment was shown in any group.
Conclusion: UV treatment of SLA surface implants significantly increased osseointegration in cortical bone. The alendronate immersion did not increase osseointegration, and there was no synergic effect with UV treatment. Further, UV treatment and alendronate immersion of machined healing abutments did not significantly increase connective tissue attachment.
Keywords: alendronate, connective tissue attachment, dental implant, dental implant abutment, osseointegration, ultraviolet
DOI: 10.11607/jomi.9642Pages 1160-1168, Language: English
Purpose: To evaluate the influence on peri-implant soft and hard tissues of one-piece implants with a convergent hyperbolic profile collar placed at different depths with respect to the bone crest.
Materials and methods: Six dogs were included in the experiment. Three months after mandibular tooth extractions, two one-piece implants carrying a 2.8-mm-high convergent hyperbolic profile collar were placed in the alveolar crest with the coronal margin of the rough surface either 0.8 mm (test-1) or 1.8 mm (test-2) deeper with respect to the bone crest (Ct0). Two similar implants were instead placed flush to Ct0 as controls (control-1 and control-2, respectively). Healing screws were connected, and nonsubmerged healing was allowed. After 4 months, block sections were harvested, and histologic slides were prepared in a buccolingual plane.
Results: In the histologic analyses, both the buccal crest and coronal level of osseointegration were located more coronally at the test compared to the control implants concerning the implant. However, the buccal bone crest with respect to Ct0 presented a loss of 0.8 ± 0.4 mm at the test-1 and 0.5 ± 0.4 mm at the control-1 implants (P = .028), and a loss of 2.0 ± 1.0 mm and 0.7 ± 0.4 mm at the test-2 and control-2 implants (P = .028), respectively. At the control implants, the collars were exposed above the peri-implant mucosa, while those of the test implants were not. However, the coronal level of the peri-implant mucosa with respect to Ct0 was located more apically at the test compared to the control implants.
Conclusion: The placement of implants with a hyperbolic convergent profile collar in the subcrestal position resulted in higher buccal bone resorption and more soft tissue recession compared to the crestal implants with respect to the level of the bone crest at placement.
Keywords: animal study, bone resorption, histology, juxta-crestal, soft tissues
DOI: 10.11607/jomi.9674Pages 1169-1175, Language: English
Purpose: To assess the thickness of the palatal bone wall of maxillary anterior teeth in relation to age, sex, and tooth type.
Materials and Methods: A total of 100 CBCT images of patients ≥ 18 years of age were used. The thickness of the palatal bone at the maxillary canines and incisors was assessed perpendicular to the long axis of the teeth at three locations: 4 mm apical to the cementoenamel junction (CEJ; MP1), halfway between the CEJ and the root apex (MP2), and at the root apex (MP3).
Results: At the MP1 site, 96% of the maxillary anterior teeth had a palatal bone thickness of < 1 mm, with a mean thickness of 0.5 mm. At the MP2 and MP3 sites, 86% and 100% of the teeth had ≥ 1 mm bone thickness, and the means were 2 and 5 mm, respectively. There were no significant differences among the age or gender groups. Maxillary canines showed significantly greater bone thickness than maxillary incisors, particularly at MP2 and MP3 sites.
Conclusion: Most of the examined teeth had thin palatal bone at the MP1 measurement site, and maxillary canines showed significantly thicker palatal bone than maxillary incisors. This finding should be considered when treatment planning for immediate implants in the maxillary anterior segment.
Keywords: CBCT, cone beam computed tomography, lingual bone wall thickness, immediate implants
DOI: 10.11607/jomi.9632Pages 1176-1185, Language: English
Purpose: To evaluate root-analog implants (RAIs) fabricated by selective laser melting (SLM).
Materials and Methods: Two types of implants (a maxillary right first molar RAI and a screw-cylinder–type molar implant) were designed using CAD software. Both implant types were fabricated with the SLM technique using Ti-6Al-4V powder. The stress distribution and micromotion of the implants were evaluated using finite element analysis, and the mechanical properties of the printed implants (relative density and compression test), surface properties of an SLM-fabricated specimen (morphology, roughness, and contact angle test), and biocompatibility of an SLM-fabricated specimen (osteoblast attachment, metal ion precipitation analysis, cell viability, and osteogenic gene expression) were evaluated.
Results: The RAI model exhibited better stress distribution and less micromotion than the screw-cylinder implant model. The screw-cylinder implant was better than the RAI at withstanding pressure, but both implant types could withstand masticatory forces. The densities of both implant types were similar to those of the bulk materials. Block samples made using the same SLM technique as the RAI exhibited good surface properties and excellent biocompatibility.
Conclusion: The properties of the molar RAI fabricated with the SLM technique suggest that it may have potential for future clinical use, but this will need to be verified by in vivo studies.
Keywords: biocompatibility, finite element analysis, mechanical properties, root-analog implant, selective laser melting, surface properties
DOI: 10.11607/jomi.9907Pages 1186-1194, Language: English
Purpose: To study the influence of insertion depth and implant angulation on the 3D trueness of models obtained with different impression techniques.
Materials and Methods: Four different reference models (model 1: parallel, depth of 1.5 mm; model 2: parallel, depth of 4 mm; model 3: 20-degree angle, depth of 1.5 mm; and model 4: 20-degree angle, depth of 4 mm) of partially edentulous maxillae were generated by altering implant angulations and subgingival depths. All scans of reference models were done with a laboratory scanner, and obtained data were exported into standard tessellation language format to be used as virtual reference images. Impressions were obtained from each reference model via three conventional techniques (closed tray [CT], non-hexed open tray [NHOT], and hexed open tray [HOT]) and one digital technique (intraoral scanning [IOS]). A total of 160 impressions were made. The reference and experimental scan data were superimposed by using the best-fit alignment algorithm. Angular (AD), linear (LD), and 3D (RMS) deviations were computed, and obtained data were statistically analyzed.
Results: In premolar implant sites, AD and LD values were significantly affected by model type (P ≤ .001 for AD and LD) and impression technique (P = .001 for AD, P = .002 for LD). However, no significant interaction was detected (P = .703 for AD, P = .768 for LD). Model 1 (0.44 ± 0.25 for AD, 7.79 ± 6.29 for LD) and the NHOT technique (0.49 ± 0.43 for AD, 9.04 ± 8.14 for LD) exhibited the lowest mean AD and LD values. In molar implant sites, AD and LD values were significantly affected by model type (P ≤ .001 for AD and LD) and impression technique (P ≤ .001 for AD and LD), as well as by their interaction terms (P = .037 for AD, P = .005 for LD). Considering interaction terms, while the highest and lowest mean AD values were exhibited by IOS-model 4 (1.56 ± 0.25) and NHOTmodel 2 (0.46 ± 0.28), respectively, the highest and lowest mean LD values were exhibited by CT-model 4 (41.40 ± 14.48) and NHOT-model 2 (8.03 ± 4.86), respectively. RMS estimate values were significantly influenced by model type (P ≤ .001) and impression technique (P ≤ .001), as well as by their interaction terms (P = .019). The highest and lowest mean RMS values were exhibited by IOS-model 4 (70.02 ± 4.74) and NHOT-model 2 (25.96 ± 17.67), respectively.
Conclusion: In the case of angulated and deeply placed implants, splinted NHOT and HOT techniques can be recommended for better trueness.
Keywords: 3D compare, 3D deviation, impression, superimposition, trueness
DOI: 10.11607/jomi.9684Pages 1195-1201, Language: English
Purpose: To compare the axial and nonaxial retention forces of different milled bar attachment designs for maxillary implant overdentures.
Materials and Methods: Four implants were placed in the canine and second premolar areas of an edentulous maxillary ridge model and connected to a cobalt-chromium milled bar either with or without Locator attachments. According to the type of bar and overlying housing, the following groups (n = 10 each) were investigated: group 1 (MWM) = milled bar without attachments and metal housing; group 2 (MWP) = milled bar without attachments and PEEK housing; group 3 (MAM) = milled bar with Locator attachments and metal housing; and group 4 (MAP) = milled bar with Locator attachments and PEEK housing. Axial and nonaxial (anterior, posterior, and lateral) retention forces were measured both at baseline and after wear simulation, then compared between groups and dislodging directions.
Results: MAM showed the highest axial (53.20 ± 2.28 N) and nonaxial (anterior [33.80 ± 1.48 N], posterior [37.60 ± 2.07 N], and lateral [34.40 ± 1.67 N]) retention forces at baseline, followed by MAP, then MWM, and MWP (P < .001). MAP showed the highest axial (42.80 ± 2.28 N) and nonaxial (anterior [24.00 ± 1.58 N], posterior [29.40 ± 2.07 N], and lateral [27.80 ± 1.64 N]) retention forces after wear simulation, followed by MAM, then MWP, and finally MWM (P < .001). MAM showed the highest axial (25.25 ± 2.45 N) and nonaxial (anterior [28.29 ± 4.03 N], posterior [24.40 ± 3.25 N], and lateral [25.55 ± 1.65 N]) retention loss, followed by MWM, then MAP, and finally MWP (P < .001). For all groups, the highest retention forces were noted with axial dislodging, followed by posterior dislodging, then lateral dislodging, and finally vertical dislodging (P < .001).
Conclusion: Milled bars with PEEK housings and Locator attachments for maxillary implant overdentures were associated with the highest axial and nonaxial retention forces after wear simulation, while milled bars with metal housing and no attachments showed the lowest forces. Milled bars with metal housing and attachments showed the highest retention loss, while milled bars with PEEK housing with no attachments showed retention gain.
Keywords: attachments, axial, implant, maxillary, milled bar, overdentures, retention
DOI: 10.11607/jomi.9682Pages 1202-1209, Language: English
Purpose: To evaluate the influence of the milliamperage and artifact reduction (AR) tool on the diagnosis of buccal and lingual peri-implant dehiscences related to titanium-zirconia (Ti-Zr) and zirconia (Zr) implants using CBCT images.
Materials and Methods: Ti-Zr and Zr implants were alternately inserted in 20 sites in the posterior region of three human mandibles that presented intact cortical (control) bones or simulated buccal and/or lingual peri-implant dehiscences. CBCT images were acquired with an OP300 Maxio unit, varied milliamperage (5 and 8 mA), and the use of AR tool. Three oral radiologists assessed the presence of dehiscences using a 5-point scale. The area under the receiver operator characteristic curve (Az), sensitivity, and specificity of each group (control and dehiscence) were obtained and compared using multiway ANOVA (α = .05).
Results: The milliamperage and the AR tool did not influence the diagnosis of dehiscences, and there were no differences between the buccal and lingual cortices (P > .05). However, Zr implants showed a higher sensitivity (0.67 to 0.89) and lower specificity (0.26 to 0.44) than Ti-Zr implants (0.19 to 0.44 and 0.93 to 1.00, respectively; P < .05). Az values did not differ between the implant types (P > .05).
Conclusions: Dehiscences were more detectable when related to Zr implants, while the absence of dehiscences was more correctly visualized adjacent to Ti-Zr implants. The use of varied milliamperages and the AR tool did not affect the diagnosis of peri-implant dehiscences, regardless of the involved cortical (buccal or lingual) bones.
Keywords: artifacts, cone beam computed tomography, dental implant, diagnosis, zirconia
DOI: 10.11607/jomi.9643Pages 1210-1216, Language: English
Dental implants present a viable treatment option for the replacement of partial and full edentulism. Since their initial creation in the 1960s, implants have proceeded to become popular among both patients and dental practitioners due to their high success and survival rates. Despite the promising results, there remains some patient hesitation toward the acceptance of implant treatment. This hesitance mainly stems from four key factors that have greatly influenced patient decision-making: financial barriers, awareness and cultural sensitivity issues, treatment timespan, and the varying possible complications. Financial barriers generally arise from the lack of insurance benefits for the surgical aspect of treatment and the differing socioeconomic statuses of the patient population. Though dental implants have become more widespread, public knowledge of the matter is still insufficient. Patients may have altered conceptions of the procedure due to insufficiently credible information sources. In addition, dental practitioners need to consider the cultural restrictions that may be existent for some patients. The long timespan of the dental implant treatment, including healing time, may result in some patients opting for fixed or removable prostheses, which have comparatively shorter treatment spans. Biomechanical overload, infection, and inflammation are varying types of complications that alter osseointegration, ultimately leading to many complications, such as peri-implantitis. These universal barriers may hinder patient acceptance of implant treatment. However, as dental health care professionals, it is important to understand this hesitance and help mitigate these obstacles through patient education and continual reassurance and support.
Keywords: edentulism, peri-implantitis, socioeconomic status, success, survival, tooth loss
DOI: 10.11607/jomi.8855Pages 1217-1222, Language: English
Purpose: To evaluate the fracture load of monolithic, single-tooth implant-supported crowns cemented on solid or Ti-base (Variobase C) abutments.
Materials and Methods: Besides abutment types (solid and Ti-base abutments), two ceramic systems (IPS e.max CAD and Zirconia inCoris ZI) and two occlusal thicknesses (0.5 and 1.5 mm) were also investigated in this study. In total, eight groups (n = 8) with 64 maxillary second premolar crowns were fabricated. All the crowns were cemented with resin cement, and the screw accesses in Ti-base groups were sealed with composite resin. After mechanical cycling, the specimens were submitted to fracture load test with the maximum force recorded in Newtons (N). Three-way analysis of variance (ANOVA) and Tukey post hoc test were used for statistical analyses (α = .05).
Results: Both the abutment type (P = .0001) and the ceramic system (P = .0001) significantly affected the results. Screw-access channels reduced the fracture load of crowns by half compared to those cemented on solid abutments. The 1.5-mm and 0.5-mm zirconia crowns placed on solid abutments had similar highest fracture loads, while the e.max CAD groups positioned on Ti-base abutments showed significantly lower values compared with other groups.
Conclusion: The screw access reduces the resistance of crowns supported by Ti-base abutments compared to crowns cemented on solid abutments. The inCoris ZI showed a higher fracture load than the IPS e.max CAD regardless of the abutment type and thickness.
Keywords: abutment, CAD/CAM, dental implant, fracture load, lithium disilicate, restoration, zirconia
DOI: 10.11607/jomi.7198Pages 1223-1231, Language: English
Purpose: To compare three different types of custom-made root-analog immediate (RAI) dental implants.
Materials and Methods: Patients with fractured and/or nonrestorable teeth with uncompromised periodontal ligaments were included in the study. The exclusion criteria were as follows: any uncontrolled systemic disease, bruxism, poor oral hygiene, active periodontal disease, and/or chronic marginal periodontitis. CBCT scans of the teeth were taken, and the datasets were used to reconstruct 3D models that were transferred to 3D modeling software to design the RAIs. Group 1 (GR1) consisted of zirconia RAIs manufactured using a computer numerical control (CNC) machine, group 2 (GR2) consisted of titanium RAIs formed by using a CNC machine, and group 3 (GR3) consisted of titanium RAIs manufactured by using direct laser metal sintering (DLMS) technology, all of which were placed immediately after tooth extraction. Primary stability was measured by using Periotest M. Metal-ceramic single crowns were cemented 3 months later. All implants were evaluated clinically and radiologically 1 year after implant placement.
Results: A total of 51 patients (18 men, 33 women) aged between 18 and 66 years (average 34.2 years) were included in the study. In 4 patients, RAIs could not be placed due to the lack of primary stability, and they were excluded. In the remaining 47 patients, the custom-made RAIs (GR1: n = 21, GR2: n = 17, GR3: n = 18, total: n = 56) were placed into fresh extraction sockets immediately after tooth extraction for each patient. Primary stability was achieved. Periotest values (PTV) were between –1.4 and –6.2 (mean –3.3). The mean initial PTV (PTV0) was –2.3 ± 1.8 for the failed implants and –4.5 ± 0.8 for the surviving implants. PTV0 was an independent risk factor (HR 3.61, 95% CI: 1.56–8.35, P = .004) for survival rate, which was 33.3%, 70.6%, and 44.4% for GR1, GR2, and GR3, respectively. The overall survival rate was 48.2%. There was no significant difference between the groups regarding the probability of survival (P = .051). The survival rate was significantly lower for anterior RAIs (P < .001). Clinically healthy gingival margins were observed without any signs of periodontitis or implant mobility, and the mean PTV was –4.0 ± 1.9 in surviving implants, whereas the mean marginal bone loss was 1.3 ± 0.6 mm (median, 0.8; 95% CI: 0.1–3.4) at the 1-year follow-up.
Conclusion: This study was the first attempt to compare different RAI manufacturing techniques and biomaterials in the literature. Although the probability of survival was not statistically significant between the groups, the survival rate in GR2 was higher than in the other two groups. Nevertheless, the overall survival rate was significantly lower (48.2%) than in the previous reports. Primary stability was an independent risk factor for failure. Further studies with the minimized variables between groups should be designed for precise results.
Keywords: anatomical, custom-made, dental implant, immediate, root analog, titanium, zirconia
DOI: 10.11607/jomi.9713Pages 1232-1243, Language: English
Purpose: To evaluate a novel proof-of-principle technique of simultaneous bone regeneration and implant placement in severely damaged sockets.
Materials and Methods: This study consisted of patients who required a single implant and presented with severe facial bone loss. Individuals were randomly assigned to either the immediate or delayed implant placement protocol. Socket reconstruction and simultaneous implant placement were performed through periostealguided bone regeneration. Implants were encased in a customized shield of autogenous cortical bone harvested from an adjacent site. Re-entry surgery was performed at 12 to 18 weeks. Peri-implant tissues and pink esthetics were assessed following established success criteria.
Results: Of the 34 patients treated, 28 patients—consisting of 15 women and 13 men with an average age of 50.8 ± 4.5 years—continued to the final follow-up. All individuals showed new facial cortical bone regeneration at second-stage implant surgery after an average healing time of 14.9 ± 2.2 weeks (range: 12 to 18 weeks). Implants remained stable after loading. Success rates were 100% at 12 months. Mean pink esthetic score (PES) was 7.8 ± 1.2 (range: 6 to 9 on a scale of 0 to 10). Linear regression analysis showed that provisionalization and attachment loss are independent risk factors affecting pink esthetics (P < .01). Mild and moderate/severe attachment loss decrease pink esthetic scores by 0.9 and 1.7 points, respectively (95% CI: 0.2–1.5; P < .01). The use of provisional restorations improves pink esthetic scores by 1.6 points (95% CI: 0.8–2.4; P < .001). A PES > 7 was four and five times more likely to be expected for delay and immediate implants, respectively, if the implant had a provisional restoration delivered post–second-stage (RR = 4 to 5; 95% CI: 1–31; P = .07; P = .02). Cramér’s V test showed a strong association between lack of implant provisionals and low pink esthetic scores (≤ 7, value = 0.7; P = .02). Facial implant transparency at follow-up was absent, and all implants had a band of keratinized tissue > 2 mm.
Conclusion: Facial bone regeneration and simultaneous implant placement is feasible in severely damaged sockets through periosteal-guided bone regeneration after a short healing period following immediate or delayed protocols. The assisted regenerated intrasocket bone allows for functional implant stability. Adjacent tooth attachment loss and lack of implant provisionalization negatively impacts pink esthetics. The proposed approach decreases costs, morbidity, and treatment duration and eliminates the need for multi-stage approaches.
DOI: 10.11607/jomi.9613Pages 1244-1249, Language: English
Purpose: This study evaluated the effect of two photobiomodulation therapy protocols on bone regeneration in criticalsize bone defects grafted with inorganic bovine bone.
Materials and Methods: A critical-size defect was created in 30 adult male rat calvaria, which were divided equally and randomly into three experimental groups (n = 10): (1) DBBM (deproteinized bovine bone mineral); (2) DBBM + PBMT 4 J (4 J; photobiomodulation therapy; GaAlAs, 730 nm, 100 mW, 140 J/cm2); and (3) DBBM + PBMT 6 J (6 J; GaAlAs, 730 nm, 100 mW, 210 J/cm2). Animals were euthanized after 30 days. The neoformed bone area (NBA), linear bone extension (LBE), and area of the remaining particles (ARP) were evaluated. The data were subjected to nonparametric Kolmogorov-Smirnov test and ANOVA, followed by Tukey post hoc test to identify differences between the groups (P < .05).
Results: The 6 J group showed the highest average NBA (48.57% ± 28.22%) and demonstrated a statistically significant difference in NBA and LBE. A higher mean ARP was found in the DBBM group (38.73 ± 6.95) than in the groups irradiated by photobiomodulation therapy, with statistically significant differences (P < .05).
Conclusion: The 6 J protocol showed the best results, promoting greater bone formation with greater resorption of residual particles.
Keywords: biomaterials, bone regeneration, bone substitutes, lasers
DOI: 10.11607/jomi.9735Pages 1250-1255, Language: English
Purpose: The objective of this study was to compare marginal bone loss (MBL) and clinical complications between surviving implants (SIs) and recently placed implants (RIs) splinted together to support a fixed partial restoration (FPR).
Materials and Methods: This retrospective study employed the medical records of patients treated with implant-supported FPRs in the Maccabi-Dent Dental Clinic. Patients were included if they were over the age of 18 years, were treated with RIs adjacent to existing SIs that had previously supported FPRs for more than 1 year, and the RIs and SIs were splinted to support new FPRs. Patients who did not receive annual follow-up or whose records had nondiagnostic radiographs or lacked sufficient restorative data were excluded. MBL was assessed at the last available radiograph and compared to one taken 1 year after loading the splinted RIs and SIs together. Clinical complication data were gathered from patient records.
Results: The medical records of 1,907 patients treated with a total of 7,306 implants were examined. Data from 187 implants were extracted from 46 patient records that met the inclusion criteria, with 96 RIs and 91 SIs supporting 56 FPRs. Mean followup was 39 ± 17.5 months. During the follow-up, two implants failed. The overall survival rate was 98.94% (98.96% in RIs and 98.91% in SIs), and the mean MBL in all implants was 0.41 ± 0.58 mm (0.4 ± 0.53 mm in RIs and 0.42 ± 0.45 mm in SIs). Peri-implantitis was reported in eight (4.3%) implants (four RIs and four SIs), screw loosening was reported in nine (4.8%) implants (three RIs and six SIs), ceramic chipping was reported in three (5.3%) restorations supported by four RIs and six SIs, and decementation was reported in one (1.8%) restoration supported by one RI and one SI. There was no statistically significant difference in survival rate, MBL, peri-implantitis, or screw loosening between RIs and SIs.
Conclusion: There was no statistically significant difference in MBL or clinical complications between RIs and SIs. Splinting RIs and SIs for new prosthetic restoration support is a reasonable treatment choice with a high implant survival rate, low incidence of complications, and acceptable MBL.
Keywords: implant complications, implant survival, marginal bone loss, old implants, splinted implant
DOI: 10.11607/jomi.9803Pages 1256-1260, Language: English
Large mandibular defects in children are an uncommon but challenging problem for surgeons to solve. The time-honored options of autologous bone grafts are seldom a viable option, as suitable donor sites are unavailable. Osteoinductive morphogens may yet provide a solution in these cases. A large mandibular tumor in a child 10 years of age necessitated the resection of the entire dentate portion of the mandible. The defect was reconstructed at a second stage with a composite graft of human transforming growth factor-β3 (hTGF-β3), human demineralized bone matrix, and 12 g of autologous bone harvested from the posterior iliac crest. A mature ossicle suitable for the placement of osseointegrated implants developed in the erstwhile defect, and an implant-supported dental prosthesis was placed. The patient has been followed up into adulthood. Facial growth has proceeded unhindered, and the patient has maintained full oral and dental function. This case reports the long-term result of an uncommon condition treated with a novel method. The longterm follow-up of this patient provides evidence to dispel some of the concerns for the use of osteoinductive proteins in children. A composite graft of osteogenic morphogens, osteocompetent autologous cells, and mineralized and demineralized matrices—as opposed to osteogenic morphogens used solo—may improve clinical bone regeneration.
Keywords: tissue engineering, human, mandible, transforming growth factor-β3, osseointegrated implants
DOI: 10.11607/jomi.9602Pages 1261-1267, Language: English
Purpose: To evaluate the effect of a simple nonsurgical procedure for the treatment of peri-implantitis.
Materials and Methods: A total of 30 implants across 24 patients diagnosed with moderate to advanced peri-implantitis were treated using a chitosan brush with adjunctive chemicals, ie, 3% hydrogen peroxide and a tetracycline slurry. The treatment was performed a total of three times, with intervals of approximately 3 weeks.
Results: Results showed improvement in both the clinical attachment level (CAL) and bleeding on probing score between the baseline and the re-examinations between 9 months and up to 43 months (mean 26.8 months) after treatment. The mean CAL at baseline was 3.4 mm (range: 1 to 8 mm), while the mean CAL during the final examination was 1.4 mm (range: 0 to 5 mm), demonstrating a mean reduction of CAL of 2 mm (range: 1 to 7 mm; P < .001). Of the analyzed implant sites, 72% demonstrated radiographic signs of osseous defect fill varying between 0.1 and 2.2 mm (mean: 1.0 mm).
Conclusion: The results show that this novel treatment strategy may serve as a nonsurgical alternative to reduce parameters of inflammation around implants with moderate to advanced peri-implantitis.
Keywords: peri-implantitis, decontaminants, retrospective, case series