Pages 163, Language: English
DOI: 10.11607/prd.4525, PubMed ID (PMID): 32032398Pages 165-169, Language: English
It is often difficult to perform the tunnel technique for root coverage and soft tissue augmentation in the mandibular anterior region where there is shallow recession and thin soft tissue, particularly when accompanied by prominent roots and alveolar undercuts. The aim of this report is to present a papilla access technique that facilitates tunnel site preparation and graft placement in such sites. This surgical access method may also be applied to sites where there is moderate to severe recession of the mandibular central incisors, and extension of the tunnel to include both the lateral incisors and canines is desired for augmentation. The papillary access provides improved surgical access for both site preparation and graft placement with reduced risk of perforation or injury to thin tissue.
DOI: 10.11607/prd.4535, PubMed ID (PMID): 32032399Pages 171-179, Language: English
Growth factors have been used in numerous oral applications to aid in bone formation after tooth extraction. Bone morphogenetic proteins (BMPs) are members of the transforming growth factor-b superfamily and are involved in the differentiation of pluripotent mesenchymal cells, leading to new bone formation through osteoblastic induction. This study examined histologic wound healing following extraction and ridge preservation using recombinant human BMP-2 (rhBMP-2) and a collagen sponge. Formation of new vital bone was seen, suggesting that this material is a viable option for ridge preservation in preparation for implant placement.
DOI: 10.11607/prd.4116, PubMed ID (PMID): 32032400Pages 181-190, Language: English
The aim of this histologic, single-blind, parallel, randomized clinical trial was to compare vertical bone augmentation grafting with 100% autogenous bone (group AB) vs 50% deproteinized bovine bone matrix (DBBM)/50% autogenous bone (group BOAB) using the Fence Technique in a two-stage implant placement. A biopsy was performed in the regenerated area at implant insertion 6 months after the augmentation surgery. The results reflect a sample size of four patients treated per group. At implant placement, 6 months after grafting, no significant differences were evident in the histomorphometric comparisons, even if the percentage of residual graft was obviously greater in the BOAB group (P = .0314).
DOI: 10.11607/prd.3597, PubMed ID (PMID): 32032402Pages 193-201, Language: English
This retrospective study evaluated hard and soft tissue response and reported mechanical and technical complications around computer-aided design/ computer-assisted manufactured (CAD/CAM) abutments. A total of 123 patients restored with titanium, gold-hue titanium, and zirconia CAD/CAM abutments were included (N = 291). Each patient was followed up for at least 2 years. Clinical and radiographic parameters were assessed annually and complications were recorded. No implant or reconstruction failures were reported. One fracture of a zirconia abutment occurred. The prosthetic survival rate after 4 years of function for restorations and abutments was 100% and 99.66%, respectively. No significant differences in biologic and radiographic indices were found. The bleeding on probing index was positive at 42% of implant sites, and it had no significant correlation with the overall change in marginal bone level (0.02 mm) of bone gain. The short-term survival of CAD/ CAM abutments was reliable, no matter of the material used for manufacturing.
DOI: 10.11607/prd.4616, PubMed ID (PMID): 32032403Pages 203-210d, Language: English
This investigation was designed to evaluate the healing response of 9.3-μm CO2 laser–assisted periodontal therapy. Five patients presenting with moderate to severe periodontitis, with an initial pocket depth (PD) ≥ 5 mm and with teeth predetermined to be surgically extracted, were enrolled and consented to treatment with full-mouth CO2 laser–assisted therapy. The laser treatment was carried out in the Ultraguide Mode at a setting of 0.25-mm spot size, with an average power of 0.65 to 1.15 watts and 20% mist. The laser tip was passed from the gingival margin and down apically to the base of the pocket with a sweeping L motion. The teeth were intensely scaled with piezoultrasonic instrumentation afterwards. A second pass of the laser tip was performed for the study teeth. At 9 months, all patients were clinically reevaluated. For sites with an initial pocket depth of ≥ 7 mm, a mean PD reduction of 3.97 ± 1.36 mm and a mean clinical attachment level gain of 3.54 ± 1.54 mm were achieved, resulting in a mean PD of 3.91 ± 0.77 mm. En bloc biopsy samples of four teeth were obtained and analyzed; two demonstrated histologic evidence of new bone formation while the other two healed with a long junctional epithelium with minimal inflammatory infiltrate. Further long-term clinical studies are needed to investigate the treatment stability obtained with a 9.3-μm CO2 laser compared to conventional surgical therapy. Nevertheless, the encouraging clinical results indicated that adjunctive use of the 9.3-μm CO2 laser–assisted periodontal therapy can be beneficial for treatment of periodontally compromised patients.
DOI: 10.11607/prd.4296, PubMed ID (PMID): 32032405Pages 213-222, Language: English
This case report aimed to describe a soft tissue approach to restore a buccal soft tissue dehiscence (BSTD) combined with the loss of peri-implant papillae and loss of periodontal attachment on the adjacent teeth. The first step of the proposed approach was the removal of the crown and abutment to leave the interproximal soft tissue to fill the space previously occupied by the crown. After 3 months, during which time the patient was wearing a provisional restoration (a temporary Maryland bridge), the implant site was treated as an edentulous area with a soft tissue augmentation procedure: the most substantial modification with respect to the original connective tissue platform technique was the use of the wide mesial and distal papillae of the implant, once de-epithelialized on the occlusal surface, as a "partial" connective platform to suture the connective grafts and submerge the implant. At the 4-month reevaluation visit, a minor soft tissue defect remained in both apico-coronal and buccolingual dimensions, and thus a second surgery was performed to obtain further soft tissue augmentation. A flapless punch procedure was used to expose the implant head, and after conditioning the augmented peri-implant soft tissue with a new provisional crown, the definitive restoration was delivered. Complete coverage of the BSTD was achieved, and both papillae entirely filled the interproximal spaces. The results were well maintained up to the 5-year follow-up visit.
DOI: 10.11607/prd.4508, PubMed ID (PMID): 32032406Pages 223-230, Language: English
Several approaches for horizontal ridge augmentation have been proposed, including guided bone regeneration (GBR), ridge split, and block grafts. Minimally invasive techniques for horizontal GBR have been introduced to reestablish an adequate bone volume, minimizing tissue trauma and patient morbidity. The present article describes a tunnel technique with a subperiosteal bag for horizontal GBR. A collagen membrane is partially perforated, folded, and sutured to form a bag that is filled with xenogeneic bone graft. The filled bag is inserted into a subperiosteal tunnel such that the perforated side faces the alveolar ridge and the nonperforated side faces the tunnel flap. The main advantage of this approach is the preservation of the periosteum and the enhanced blood supply to the flap, which may contribute to increased favorable wound healing and a reduced risk of flap dehiscence and membrane exposure. This novel tunnel approach for horizontal GBR using a customized bag made from a collagen membrane, specifically adapted and filled with deproteinized bovine bone, resulted in a significant ridge volume gain that allowed implant placement.
DOI: 10.11607/prd.4494, PubMed ID (PMID): 32032408Pages 233-243, Language: English
This study aimed to evaluate with laser Doppler flowmetry (LDF) the effect of topical hyaluronic acid (HA) application on the vascularization of free gingival graft (FGG) donor and recipient sites during the early wound healing period and to investigate the effect of HA application on the dimensional change of the FGG. Forty systemically healthy, nonsmoking patients who required FGG due to insufficient amount of attached gingiva in a partial edentulism were randomly assigned to a study group: test (FGG+HA) or control (FGG alone). The LDF values of the donor and recipient sites were measured in both groups before the operation and at 4, 7, 10, 14, and 30 postoperative days. LDF measurement of the graft was performed as soon as the graft was taken from the palatal site. FGG dimensions (width, height, and thickness) were assessed and recorded at baseline and on day 30, as well as the percentage of the changes in these values. LDF values of the recipient site in the FGG+HA group were found to be statistically higher than those in the control group on days 4 and 7 (P = .013 and P = .020, respectively); however, no differences were found for days 10, 14, and 30. Additionally, no differences were found for the LDF values of the palatal site between the FGG+HA and control groups (P > .05) at all examined time points. The height of the graft measured on day 30 was statistically higher in the FGG+HA than the control group (P < .001). The percentage change in thickness and height of the FGG was statistically lower in the FGG+HA than control group (P = .028 and P < .001, respectively). Application of HA on the recipient bed under the FGG at the first week of healing allows the formation of a well-vascularized layer, which acts as a barrier against tissue tensions by functioning as a scaffold between the recipient bed and FGG, thus reducing the shrinkage of the graft, especially in the vertical direction. This study further showed that the graft taken from the donor site had a remaining blood perfusion value of its own.
DOI: 10.11607/prd.3952, PubMed ID (PMID): 32032409Pages 245-252, Language: English
To correct for angulation discrepancies in the maxilla, implant companies have designed angulated screw channel (ASC) abutments. The design of these abutments allows for the restorative screw channel to be placed up to 25 degrees off the center axis of the implant. Minimal independent research has been published to evaluate the fatigue resistance of this implant-abutment connection. This study evaluated the fracture strength of a newly designed zirconia crown with a 25-degree angulated screw channel (n = 5) vs a straight channel (n = 5). Each specimen was subjected to an off-axis compression load from an MTS cyclic loading machine with a custom-designed indenter simulating a natural dentition. All the 25-degree angulated screw channel specimens failed, with four of the five (80%) catastrophically failing. Four of the five straightchannel specimens failed, with two of the five (40%) catastrophically failing. Results revealed the potential abutment fracture from internal stresses at the screw-zirconia and metallic-zirconia interfaces. Further research is needed to test the use of all-ceramic crowns with the use of the angulated screw channel.
DOI: 10.11607/prd.4210, PubMed ID (PMID): 31714540Pages 253-259, Language: English
In the present study, the authors evaluated the association of canine impaction with different skeletal discrepancies in two planes of space (sagittal and vertical). Cephalometric and orthopantomographic radiographic images of 45 patients with one or more impacted canines were used in this retrospective study. Five radiographic morphologic parameters—ANB angle, canine angulation, angle between the Frankfort horizontal plane and the mandibular plane (FHMP), Wits appraisal analysis, and axial inclination of the maxillary incisors in the sagittal plane—were recorded for comparison. Statistical analysis was performed using SPSS 9.0 statistical package (IBM). Impaction of the maxillary canine was more frequent than mandibular canine impaction in both males and females, and palatal impaction was more common than buccal impaction, with a higher significance in males (64.7%) than in females (50%). In the sagittal relationship, the highest frequency of impacted canines was found in patients with a Class III skeletal discrepancy (44.4%), followed by Class I (28.9%) and Class II division 1 (15.6%), while the lowest frequency was in Class II division 2 (11.1%). Comparison between sexes in the vertical plane showed that impacted canines occurred more frequently in hyperdivergent female faces (51.1%) and hypodivergent male faces (48.9%). The result of this study indicates a statistically significant association of impaction with canine, sagittal, and/ or vertical dentofacial discrepancies. The results also showed a higher risk of having impacted canines in patients with certain dentofacial deformities. Therefore, canine impaction may be used to represent a substitute scale for the study of different malocclusion groups with respect to race and ethnicity.
DOI: 10.11607/prd.4101, PubMed ID (PMID): 32032410Pages 261-270, Language: English
The objective of this study was to verify differences in eye-tracking metrics and subjective smile esthetic ratings between general practitioners, orthodontists, and laypersons in cases of maxillary lateral incisor gingival margin deviations. Unilateral apical and incisal gingival margin deviations of 1, 2, and 3 mm were digitally produced in pictures of a man and a woman smiling. Specific areas of interest (AOIs) were created in each picture. Eye-tracking metric data included the time to first fixation (TFF) and number of fixations (NF). A specific sensor and software were used to acquire information on the eye movements. Data on the smile esthetic ratings were obtained using a visual analog scale (VAS). Analysis of variance and Pearson correlation were applied. The TFF on the AOIs in the mouth was shorter for general practitioners and orthodontists, signifying that general practitioners and orthodontists rapidly perceived the features in these areas, while for laypersons, the TFF was shorter for the AOIs of the eyes (P < .05). The NF was greater on the AOIs in the mouth for general practitioners and orthodontists, whereas to the laypersons, the NF tended to be greater on the AOIs in the eyes. Mean VAS scores differed between observer groups (P < .05). For the male picture, the 1-mm and 2-mm apical gingival margin deviations received the highest scores from the laypersons, while for both female and male pictures, the 1-mm apical deviation received the highest scores from the general practitioners and orthodontists. Higher VAS scores resulted in longer times that general practitioners and orthodontists spent looking at the gingival margin changes. General practitioners and orthodontists differ from laypersons in their perceptions of smile esthetics. Eye-tracking metrics revealed that the AOIs in the mouth aroused greater interest from the general practitioners and orthodontists, and this interest became greater as the gingival margin deviations increased to 3 mm. Laypersons fixated more on the AOIs of the eyes. The VAS scores indicated that general practitioners and orthodontists were more critical than laypersons, accepting smaller deviations in the gingival margins of the maxillary lateral incisors.
DOI: 10.11607/prd.3893, PubMed ID (PMID): 32032411Pages 271-276, Language: English
In order to obtain a more-natural esthetic prothesis, the use of hybrid abutments is becoming widespread in implant dentistry. The aim of this in vitro study was to assess the effects of different surface treatments, as well as the effects of different combinations of surface treatments and cementation protocols, on the shear bond strength between titanium alloy disks and lithium disilicate glass-ceramics. Forty titanium-alloy disks (4 × 6.6 mm) were fabricated using computer-aided designed/computer-assisted manufacturing, and an identical number of lithium disilicate glass-ceramic disks of similar sizes were fabricated by a heat-pressing technique to be attached to the titanium disks. The specimens from each material group were divided into two groups (n = 20 each) according to the surface treatment type: alumina airborne-particle abrasion or etching with hydrofluoric acid. Each group was then divided into two subgroups (n = 10) depending on the resin-cement type: Multilink Hybrid Abutment Cement (Ivoclar Vivadent) or PANAVIA SA Cement Plus (Kuraray). After thermocycling (5,000 cycles), a shear bond strength (SBS) test was conducted using a universal testing machine. Statistical analysis was performed by analysis of one-way analysis of variance and unpaired tests (P < .05). Statistically, the highest SBS values were obtained using airborne-particle abrasion. The surface treatment of titanium alloys by sandblasting led to a higher SBS compared to etching with hydrofluoric acid. The cement type also had a significant influence on SBS results.
DOI: 10.11607/prd.4531, PubMed ID (PMID): 32032413Pages 279-283, Language: English
This investigation has been stimulated by the Osseointegration Foundation, working in conjunction with the Zest Anchors implant company. There are three basic valuable activities that emerge from a professional foundation, which were reflected in this case study. They include disseminating information to practitioners, to persuade young clinicians to become research investigators, and to reach out to patients in need of treatment who cannot afford it without a charitable opportunity.
DOI: 10.11607/prd.4327, PubMed ID (PMID): 32032414Pages 285-291, Language: English
The purpose of this study was to evaluate the effect of implant platformswitching design and abutment materials on the stress distribution around implants. Implants were fixed in epoxy-resin models restoring posterior missing first molars, representing two main groups according to the implant-abutment connection. Each group was subdivided according to the type of abutment material used (titanium or zirconia). Twenty monolithic fully anatomical zirconia crowns were fabricated. Stress analysis was measured around the implants using strain gauges during the static loading of each implant-supported crown. Data were collected, tabulated, and statistically analyzed. Standard implant-abutment connection groups recorded the highest (statistically significant; P < .05) mean strain values compared to platform-switching connection groups. Abutment materials in both groups recorded statistically nonsignificant (P > .05) mean strain values. The platform-switching concept showed better crestal-bone stress distribution around implant-supported restorations. Abutment materials expressed no statistically significant effect on the stress distribution around implant-supported restorations. Zirconia and titanium abutments could withstand the functional loads developed during physiologic chewing in the molar area.
DOI: 10.11607/prd.3932, PubMed ID (PMID): 32032415Pages 293-300, Language: English
This article reports a comprehensive restorative treatment using bulk-fill composites and discusses their properties and clinical performance. A 20-yearold man sought dental treatment due to the dark shade of his smile and multiple old amalgam fillings. Based on clinical and radiographic findings, and the patient's demand for tooth-colored fillings, treatment comprised enamel microabrasion and in-office dental bleaching, followed by the replacement of amalgam fillings by bulk-fill composites. Bulk-fill composites exhibit modifications in the filler size and shape or in the chemistry of monomers that allow them to be applied in thicker layers (4 to 5 mm), creating opportunities for simpler, faster, and more-efficient clinical procedures, as seen in the present report.
Online OnlyDOI: 10.11607/prd.4452, PubMed ID (PMID): 32032401Pages 35-41, Language: English
Inflammatory odontogenic cysts, if not treated, may lead to progression of osteolytic activity, potential paresthesia, and loss of teeth. A 16-year-old female patient was referred by a pediatric dentist for asymptomatic abnormal radiolucency found interproximally to the mandibular left first and second premolars. Radiographic, clinical, and pathologic analyses led to a diagnosis of an inflamed odontogenic cyst (type K09.0) with Actinomyces colonization. The cyst was treated by periodontal regenerative therapy and resulted in successful osseous regeneration. This was a rare case because of the patient's age, the location of the lesion, its association with vital teeth, and its presentation.
Online OnlyDOI: 10.11607/prd.4505, PubMed ID (PMID): 32032404Pages 43-51, Language: English
The aim of this randomized controlled trial was to compare the clinical outcomes of modified coronally advanced tunnel technique (MCAT) with subepithelial connective tissue graft (SCTG) with and without recombinant human plateletderived growth factor-BB (rhPDGF-BB) for mandibular multiple recessions. Twenty-four Miller Class I and III recessions were randomly assigned to a group: test (MCAT+SCTG+rhPDGF-BB) or control (MCAT+SCTG). After 6 months, mean recession-depth reduction was higher in the test group (2.08 ± 0.90 mm) than the control (1.83 ± 0.93 mm). Mean root coverage was achieved, favoring the test group (82.6% ± 23.69%) instead of the control (56.2% ± 28.55%). Complete root coverage for the test group was 58.3%, which was significantly superior to control (16.7%). The use of rhPDGF-BB+SCTG using MCAT offered an advantage of a minimally invasive, predictable method for achieving optimal outcomes.
Online OnlyDOI: 10.11607/prd.4416, PubMed ID (PMID): 32032407Pages 53-63, Language: English
This meta-analysis aimed to evaluate the clinical effectiveness of autologous platelet concentrates (APC) + coronally advanced flap (CAF) (Group A) compared with connective tissue graft (CTG) + CAF (Group B), and CAF alone (Group C), in patients with Miller Class I or II gingival recessions. Relevant articles published before December 2018 were retrieved electronically without date or language restriction and screened according to inclusion criteria. Quantitative meta-analysis was conducted comparing the groups. The inverse variance method was applied in fixed or random effects models according to heterogeneity. Sixteen randomized controlled trials were included. Root coverage (RC), clinical attachment level (CAL), gingival thickness (GT), and probing depth (PD) did not differ significantly between Groups A and B. The keratinized gingival width (KGW) of Group A was significantly less than that of Group B. The RC and GT of Group A were significantly greater than that in Group C. CAL and PD for Group A were lower than for Group C. KGW for Group A did not differ significantly from that of Group C. The results suggested that APC + CAF represents a promising alternative for root coverage for Miller Class I and II gingival recession defects. Nevertheless, CTG + CAF exhibits superior outcomes in terms of KGW. Hence, in scenarios lacking keratinized gingiva (Miller Class II), APC + CAF might not be the most suitable therapeutic choice.
Online OnlyDOI: 10.11607/prd.4258, PubMed ID (PMID): 32032412Pages 65-72, Language: English
Despite the widespread use of cone beam computed tomography (CBCT), few articles have been published to assess the accuracy in detecting alveolar bone defects using different CBCT exposure settings. A human cadaver with rounded bone defects in various locations was scanned using a CBCT scanner at different settings. Four examiners twice studied 1,500 crosssectional digital and printed slices for defect presence, location, and size. High-resolution zoom mode achieved the highest overall accuracy. Moreover, apical location of the defects significantly affected overall accuracy. Bone defect detection depends upon exposure settings of CBCT scans. Exposure settings and field of view dimensions should be individualized per case.
Online OnlyDOI: 10.11607/prd.4359, PubMed ID (PMID): 32032416Pages 73-83, Language: English
This study aimed to create papilla with concentrated growth factor (CGF) in cases in which the interdental papilla was not able to fill the interproximal space (IPS) due to physiologic factors. A three-dimensional digital model of this space with the digital impression obtained from direct intraoral scanning of IPS was created. This study aimed to evaluate the efficacy of CGF in the regeneration of multiple adjacent papillary losses (MAPL), with the change in the IPS area calculated on intraorally scanned images obtained with digital impressions. This study included 160 teeth from 40 patients with 120 papillary losses. Patients were randomly allocated to the test group (TG) (n = 20), with 60 MAPL (three adjacent, lost interdental papillae per patient) receiving minimally invasive surgery with CGF, or the control group (CG) (n = 20), with 60 MAPL without surgery. A total of 480 images were uploaded to a software. The patients' age, gender, Plaque Index, bleeding on probing, and mean probing pocket depth values were evaluated. Papillary area (PA) were calculated between the two central, lateral-central, and lateral-canine teeth at baseline and posttreatment periods of 3, 6, and 12 months in both groups. Papillary filling percentage, keratinized-gingiva width, papillary thickness, thrombocyte, count and mean platelet volume were recorded in TG. Considering the variables in TG and CG, there was no difference in terms of age, gender, and periodontal parameters (P > .05). PA at 3, 6, and 12 months showed statistically significant differences from baseline values in TG (P < .001) but not in CG (P > .05). In TG, a moderate positive correlation was found between the midline papillary thickness and the 3-, 6-, and 12-month filling percentages (r: 0.506, P = .023; r: 0.509, P = .022; and r: 0.515, P = .02, respectively), and a high positive correlation was determined between thrombocyte count and the 6- and 12-month filling percentages (r: 0.733, P < .001; and r: 0.744, P < .001, respectively). CGF provided papillary regeneration in the treatment of MAPL and supported threedimensional structure of the regenerated interdental papilla throughout 1 year.