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Aim: To evaluate the healing outcomes in non-molar post-extraction sockets filled with deproteinized bovine bone mineral with collagen (DBBM-C) as a function of time., Materials and Methods: Patients in need of non-molar tooth extraction were randomly allocated into one of three groups according to the total healing time (A-3 months; B-6 months; C-9 months). The effect of alveolar ridge preservation (ARP) therapy via socket filling using DBBM-C and socket sealing with a porcine collagen matrix (CM) was assessed based on a panel of clinical, digital, histomorphometric, implant-related, and patient-reported outcomes., Results: A total of 42 patients completed the study (n = 14 in each group). Histomorphometric analysis of bone core biopsies obtained at the time of implant placement showed a continuous increase in the proportion of mineralized tissue with respect to non-mineralized tissue, and a decrease in the proportion of remaining xenograft material over time. All volumetric bone and soft tissue contour assessments revealed a dimensional reduction of the alveolar ridge overtime affecting mainly the facial aspect. Linear regression analyses indicated that baseline buccal bone thickness is a strong predictor of bone and soft tissue modelling. Ancillary bone augmentation at the time of implant placement was needed in 16.7% of the sites (A:2; B:1; C:4). Patient-reported discomfort and wound healing index scores progressively decreased over time and was similar across groups., Conclusions: Healing time influences the proportion of tissue compartments in non-molar post-extraction sites filled with DBBM-C and sealed with a CM. A variable degree of alveolar ridge atrophy, affecting mainly the facial aspect, occurs even after performing ARP therapy. These changes are more pronounced in sites exhibiting thin facial bone (≤1 mm) at baseline (Clinicaltrials.gov NCT03659617)., (© 2022 The Authors. Journal of Clinical Periodontology published by John Wiley & Sons Ltd.)

This study evaluated a panel of clinical, dimensional, volumetric, implant-related, histomorphometric, and patient-reported outcome measures (PROMs) following reconstruction of dehiscence defects in extraction sockets with a minimally invasive technique using particulate bone allograft and a nonresorbable dense polytetrafluoroethylene (dPTFE) membrane. Subjects (n = 17) presenting severe buccal dehiscence defects at the time of single-rooted tooth extraction participated in the study. The mean vertical dimension of the dehiscence defects at baseline was 5.76 ± 4.23 mm. Subjects were followed up at 1, 2, 5, and 20 weeks postoperatively. The dPTFE barrier was gently removed at 5 weeks. CBCT and intraoral scans were obtained at baseline and at 20 weeks. A bone core biopsy sample was harvested at 24 weeks (before implant placement). Linear radiographic measurements revealed a mean increase in buccal bone height from baseline to 20 weeks (5.66 ± 5.1 mm; P < .0001). A total alveolar bone volume gain of 9.12% was observed. Although approximately half of the sites required some degree of additional bone augmentation at the time of implant placement, all implants were placed in a favorable restorative position with adequate primary stability. Histomorphometric analyses revealed a mean mineralized tissue area of 31.04% ± 15.22%, and the proportions of remaining allograft material and nonmineralized tissue were 16.23% ± 10.63% and 52.71% ± 9.53%, respectively. All implants survived up to 12 months after placement. PROMs were compatible with minimal discomfort at different postoperative stages and a high level of overall satisfaction upon study completion. This study demonstrated that the reconstructive procedure employed was successful and predictable in treating large, postextraction alveolar ridge deformities to optimize tooth replacement therapy with implant-supported prostheses.

Purpose: This study sought to define the tissue responses at different implant-abutment interfaces by studying bone and peri-implant mucosal changes using a 5-year prospective randomized clinical trial design study. The conus interface was compared with the flat-to-flat interface and platform-switched implant-abutment systems., Materials and Methods: One hundred forty-one subjects were recruited and randomized to the three treatment groups according to defined inclusion and exclusion criteria. Following implant placement and immediate provisionalization in healed alveolar ridges, clinical, photographic, and radiographic parameters were measured at 6 months and annually for 5 years. The calculated changes in marginal bone levels, peri-implant mucosal zenith location, papillae lengths, and peri-implant Plaque Index and bleeding on probing were statistically compared., Results: Forty-eight conus interface implants, 49 flat-to-flat interface implants, and 44 platform-switched implants were placed in 141 subjects. Six platform-switched interface and eight flatto- flat interface implants failed, most of them within 3 months. After 5 years, 33 conical interface, 28 flat-to-flat interface, and 27 platform-switched interface implants remained for evaluation. Calculation of marginal bone level change showed a mean marginal bone loss of -0.16 ± 0.45 (-1.55 to 0.65), -0.92 ± 0.70 (-2.90 to 0.20), and -0.81 ± 1.06 (-3.35 to 1.35) mm for conical interface, flat-to-flat interface, and platform-switched interface implants, respectively (P < .0005). The peri-implant mucosal zenith changes were minimal for all three interface designs (0.10 mm and +0.08 mm, P > .60). Only 16% to 19% of the surfaces had presence of bleeding on probing, with no significant differences (P > .81) between groups. Interproximal tissue changes were positive and similar among the implant interface designs., Conclusion: Over 5 years, the immediate provisionalization protocol resulted in stable peri-implant mucosal responses for all three interfaces. Compared with the flat-to-flat and platform-switched interfaces, the conical interface implants demonstrated significantly less early marginal bone loss. The relationship of marginal bone responses and mucosal responses requires further experimental consideration.

Alveolar ridge preservation (ARP) therapy is indicated to attenuate the physiologic resorptive events that occur as a consequence of tooth extraction with the purpose of facilitating tooth replacement therapy. This randomized controlled trial was primarily aimed at testing the efficacy of ARP as compared with unassisted socket healing. A secondary objective was to evaluate the effect that local phenotypic factors play in the volumetric reduction of the alveolar bone. A total of 53 subjects completed the study. Subjects were randomized into either the control group, which involved only tooth extraction (EXT n = 27), or the experimental group, which received ARP using a combination of socket grafting with a particulate bone allograft and socket sealing with a nonabsorbable membrane (dPTFE) following tooth extraction (ARP n = 26). A set of clinical, linear, volumetric, implant-related, and patient-reported outcomes were assessed during a 14-wk healing period. All linear bone assessments (horizontal, midbuccal, and midlingual reduction) revealed that ARP is superior to EXT. Likewise, volumetric bone resorption was significantly higher in the control group (mean ± SD: EXT = -15.83% ± 4.48%, ARP = -8.36% ± 3.81%, P < 0.0001). Linear regression analyses revealed that baseline buccal bone thickness is a strong predictor of alveolar bone resorption in both groups. Interestingly, no significant differences in terms of soft tissue contour change were observed between groups. Additional bone augmentation to facilitate implant placement in a prosthetically acceptable position was deemed necessary in 48.1% of the EXT sites and only 11.5% of the ARP sites ( P < 0.004). Assessment of perceived postoperative discomfort at each follow-up visit revealed a progressive decrease over time, which was comparable between groups. Although some extent of alveolar ridge remodeling occurred in both groups, ARP therapy was superior to EXT as it was more efficacious in the maintenance of alveolar bone and reduced the estimated need for additional bone augmentation at the time of implant placement (ClinicalTrials.gov NCT01794806).

Purpose: The implant-abutment interface may affect peri-implant mucosal architecture, and influence health and esthetics. The goal of this 1-year follow-up report of a 5-year clinical investigation was to examine the peri-implant mucosal tissue responses to different implant-abutment interface designs., Materials and Methods: Subjects requiring an anterior maxillary implant were recruited. Tooth extractions, with or without preservation or ridge augmentation procedures, were performed as required. After 5 months of healing, one of three different implant-abutment combinations (conical interface [CI] n = 48); flat-to-flat interface [FI] n = 49); or platform switch interface [PS] n = 44) was placed and provisionalized. Twelve weeks later, permanent crowns were placed and data gathered throughout the first year. Peri-implant mucosal architecture and bone levels were evaluated clinically, photographically, and radiographically., Results: At 1 year, seven FI and six PS implants failed and two FI and two PS implant participants were lost to follow-up, resulting in survival rates of 100% (CI), 85.7% (FI), and 86.4% (PS) (90.8% overall). Marginal bone level changes were -0.22 mm (CI, P < .05), -1.2 mm (FI, P < .05), and -1.32 mm (PS, P < .05) after 1 year. Marginal bone level stability (≤ 0.5-mm bone loss or gain) was recorded for 87% (CI), 8% (FI), and 27% (PS) of implants. Measurement of midbuccal mucosal zenith and papilla positions revealed no change in the mucosal positions and 0.2 to 0.3 mm of gain in papilla dimensions in all groups., Conclusion: Significant differences in marginal bone loss were observed among the three implant-abutment interfaces. At 1 year follow-up, changes in the buccal mucosal zenith position or papilla dimensions were not discernable. A continued longitudinal evaluation of peri-implant bone and mucosal changes around these different interfaces is ongoing.