Half- and full-grafting alveolar ridge preservation with different sealing materials: A three-arm randomized clinical trial.

OBJECTIVE: The objective of this study is to investigate the effect of different alveolar ridge preservation (ARP) approaches on bone resorption and their potential for facilitating implant placement. MATERIALS AND METHODS: Patients who underwent one or two tooth extractions with a desire for restoration were included in the study. The participants were randomly assigned to one of three groups for ARP. The groups were as follows: (1) Half grafting of bovine bone mineral (DBBM-C) covered with non-resorbable dense polytetrafluoroethylene (dPTFE) membrane (Test 1 group); (2) Half grafting of bovine bone mineral (DBBM-C) covered with collagen membrane (Test 2 group); and (3) Full grafting with collagen membrane (DBBM-C + Collagen membrane) as the Control group. After 6-month healing period, the evaluation encompassed clinical, radiographic, implant-related outcomes, and the factors contributing to hard and soft tissue alterations. RESULTS: Enrollment in this study comprised 56 patients. At the 6-month follow-up, radiographic analysis in computed beam computed tomography images was conducted for 18, 19, and 19 patients with 18, 20, and 20 tooth sites in Test 1, Test 2, and Control groups, respectively. Additionally, a total of 15, 17, and 17 patients with 15, 18, and 17 implants were evaluated. Based on radiographic analysis, all groups showed limited ridge resorption at 1 mm from crest horizontally (Test 1: 1.29 ± 1.37; Test 2: 1.07 ± 1.07; Control: 1.54 ± 1.33 mm, p = 0.328), while the Control group showed greater radiographic bone height gain in mid-crestal part vertically (Test 1: 0.11 ± 1.02; Test 2: 0.29 ± 0.83; Control: -0.46 ± 0.95 mm, p = 0.032). There were no significant intergroup differences in terms of keratinized mucosal width, bone density, insertion torque, and the need of additional bone graft. However, the use of a dPTFE membrane resulted in a significantly higher vertical mucosal thickness (Test 1: 2.67 ± 0.90; Test 2: 3.89 ± 1.08; Control: 2.41 ± 0.51 mm, p < 0.001). CONCLUSIONS: The study showed comparable dimensional preservation with limited vertical shrinkage, while thin buccal bone plate, non-molar sites, and large discrepancy between buccal and palatal/lingual height may contribute to greater shrinkage. Thicker mucosa with dPTFE membrane required further investigation for interpretation. CLINICAL TRIAL REGISTRATION NUMBER: NCT06049823. This clinical trial was not registered prior to participant recruitment and randomization.

Depth of mucosal tunnel in peri-implant health during 12-month follow-up in patients with controlled periodontitis.

BACKGROUND: The association between thickness of peri-implant mucosa, known as mucosal tunnel (MT) and related clinical parameters in bone-level implants has not been investigated. METHODS: Posterior implants, in patients with controlled periodontitis, were evaluated at different time intervals: during uncovering surgery (T0 ), 2-month after uncovering surgery (T2M ) and 12-month after placement (T12M ). Clinical parameters including vertical soft tissue height (VSTH), MT, tooth-implant discrepancy of bone level (DBL), pocket depth (PD), peri-implant marginal bone loss (MBL), emergence profile and emergence angle (EA) were collected, and the correlation were assessed at different time points. RESULTS: Forty-two patients with 60 implants were recruited, and 81.7% of the patients were Stage III-IV, Grade B-C generalized periodontitis. MT presented no significant difference in PD, VSTH, and MBL. Periodontitis Grade C and absence of bone regeneration were significant predictors for deep MT (>3 mm), and 5.850 less EA at mesial side of implants (p = 0.02).The regression of analysis implied the increase of DBL 1 mm would cause 0.26 mm deeper MT, 1.7 times higher risk of having deep MT (p = 0.041; OR = 1.731; 95% CI:1.02-2.93) and 2.1 times higher risk of having circumferential PD > 4 mm (p = 0.019; OR = 2.1; 95% CI:1.13-3.92). CONCLUSIONS: In bone-level implants, a correlation between MT and clinical parameters at 12-month follow-up was not found. However, history of periodontitis Grade C, absence of bone regeneration and tooth-implant discrepancy of bone level might define the depth of MT. Additionally, the depth of MT played a critical role in determining restorative design.

Soft tissue phenotype modification impacts on peri-implant stability: a comparative cohort study.

OBJECTIVES: Soft tissue phenotype modification (STPM) could be performed to maintain peri-implant health. Therefore, the aim of the study was to analyze tissue alteration around implants following soft tissue phenotype modification during implant uncovering surgery. MATERIALS AND METHODS: Patients who had STPM (either pouch roll or modified roll technique) during implant second-stage surgery with at least 12-month follow-up were included. Clinical and radiographic parameters including mucosal tissue thickness (MTT), recession (REC), keratinized mucosa width (KMW), probing pocket depth (PPD), marginal bone loss (MBL), emergence profile, and emergence angle were extracted from 2-week, 2-month, and 12-month visits after second-stage surgery. RESULTS: Twenty-eight patients with 33 implants that fulfilled the inclusion criteria were included. After soft tissue phenotype modification, at 2 weeks, REC was negatively correlated to mean MTT at mid-buccal site (r = - 0.41, p = 0.018) and borderline correlated at mid-lingual site (r = - 0.343, p = 0.051). Stable KMW was maintained from 2 weeks to 12 months with minimal shrinkage rate (3 ~ 14%). MBL change was limited (0.24 ~ 0.47 mm) after STPM. All implants had shallow PPD (≤ 3 mm) with the absence of bleeding on probing. Emergence angle at the mesial side, however, was significantly correlated to surgical techniques, which indicated pouch roll technique would have 6.96 degrees more than modified roll technique (p = 0.024). CONCLUSIONS: Soft tissue phenotype modification, either pouch roll or modified roll technique, during uncovering surgery resulted in favorable clinical outcomes. Thin mucosal tissue thickness and pouch roll technique are the factors related to more recession at 2 weeks. Pouch roll technique could influence the restorative design by having a wide emergence angle at the mesial side. CLINICAL RELEVANCE: Modified and pouch roll techniques during uncovering surgery were viable methods to yield favorable peri-implant health, while the preciseness of pouch roll technique was required to avoid mucosal recession and inadequate restorative design.

The predictive performance of surgical treatment in upper molars with combined bony defect and furcation involvement: a retrospective cohort study.

BACKGROUND: To evaluate the impact of combined defects, bony destruction and furcation involvement, on disease resolution after surgery in terms of pocket elimination, absence of inflammation, furcation improvement and predictive performance. METHODS: Combined bony (intrabony (+) or (-)) and furcation defects (FI degree 1 or 2) at maxillary molars in patients diagnosed as periodontitis stage III to IV, being through periodontal surgery and at least 6 months follow-up were retrospectively screened. Cumulative predictability (CR, %), failure of treatment and the change of clinical parameters from baseline at pre-operative visit to the latest maintenance care, including pocket depth (PD), horizontal and vertical furcation involvement (FI) were analyzed. Failure of treatment with low predictability was defined as residual PD > 4 mm with bleeding on probing during maintenance period. RESULTS: Thirty-three patients with fifty-one combined defects were included. Statistical analysis showed significant overall PD reduction and FI improvement (p < 0.001). Combined FI degree 2 with intrabony (+) defects revealed more horizontal furcation improvement compared with FI degree 2 with suprabony defect (p = 0.007). However, type of combined defects was not relevant to CR (p = 0.702) and PD reduction (p = 0.707). Among all parameters, baseline PD with proximal FI degree 2 was indicated to failure of treatment. CONCLUSIONS: Different types of combined defects, deep baseline pocket and proximal FI degree 2 would compromise the predictability of treatment outcomes in upper molars. Nevertheless, the combination of surgical treatment and strict maintenance care could still yield high predictability and survival rate. TRIAL REGISTRATION: retrospectively registered.