Factors influencing outcomes of surgical therapy of peri-implantitis: A secondary analysis of 1-year results from a randomized clinical study.

AIM: To identify predictors of treatment outcomes following surgical therapy of peri-implantitis. MATERIALS AND METHODS: We performed a secondary analysis of data from a randomized controlled trial (RCT) comparing access flap with or without bone replacement graft. Outcomes at 12 months were probing pocket depth (PPD), bleeding on probing (BOP), soft-tissue recession (REC) and marginal bone level (MBL) change. Multilevel regression analyses were used to identify predictors. We also built an explanatory model for residual signs of inflammation. RESULTS: Baseline PPD was the most relevant predictor, showing positive associations with final PPD, REC and MBL gain, and negative association with probability of pocket closure. Smokers presented higher residual PPD. Absence of keratinized mucosa at baseline increased the probability of BOP but was otherwise not indicative of outcomes. Plaque at 6 weeks was detrimental in terms of residual PPD and BOP. Treatment allocation had an effect on REC. Final BOP was explained by residual PPD ≥6 mm and plaque at more than two sites. CONCLUSIONS: Baseline PPD was the most relevant predictor of the outcomes of surgical therapy of peri-implantitis. Pocket closure should be a primary goal of treatment. Bone replacement grafts may be indicated in aesthetically demanding cases to reduce soft-tissue recession. The importance of smoking cessation and patient-performed plaque control is also underlined.

The adjunctive effect of a resorbable membrane to a xenogeneic bone replacement graft in the reconstructive surgical therapy of peri-implantitis: A randomized clinical trial.

AIM: To evaluate the potential adjunctive effect of a resorbable collagen membrane covering a xenogeneic bone replacement graft in the reconstructive surgical therapy of peri-implantitis. MATERIALS AND METHODS: Forty-three patients (43 implants) diagnosed with peri-implantitis associated with intra-bony defects were treated with a surgical reconstructive approach that included a xenogeneic bone substitute material. Additionally, resorbable collagen membranes were placed over the grafting material at sites randomly allocated to the test group; conversely, no membranes were placed in the control group. Clinical outcomes, namely probing pocket depth (PPD), bleeding and suppuration on probing (BoP and SoP), marginal mucosal level (REC) and keratinized mucosa width (KMW), were recorded at baseline and 6 and 12 months after surgery. Radiographic marginal bone levels (MBLs) and patient-reported outcomes (PROs) were assessed at baseline and 12 months. A composite outcome (success) was evaluated at 12 months, which included the absence of BoP/SoP, PPD ≤5 mm and reduction of buccal marginal mucosal level (buccal REC) of ≤1 mm. RESULTS: At 12 months, no implants were lost and treatment success was observed at 36.8% and 45.0% of implants in the test and control groups, respectively (p = .61). Similarly, there were no significant differences between groups in terms of changes of PPD, BoP/SoP, KMW, MBL or buccal REC. Post-surgical complications were observed in the test group only (e.g., soft tissue dehiscence, exposure of particulate bone graft and/or resorbable membrane). Longer surgical times (~10 min; p < .05) and higher levels of self-reported pain at 2 weeks (p < .01) were observed in the test group. CONCLUSIONS: This study failed to demonstrate the presence of added clinical or radiographic benefits of the use of a resorbable membrane to cover a bone substitute material within the reconstructive surgical therapy of peri-implantitis associated with intra-bony defects.

Reconstructive surgical therapy of peri-implantitis: A multicenter randomized controlled clinical trial.

OBJECTIVE: To evaluate the potential benefit of the use of a bone substitute material in the reconstructive surgical therapy of peri-implantitis. METHODS: In this multicenter randomized clinical trial, 138 patients (147 implants) with peri-implantitis were treated surgically, randomized by coin toss to either a control (access flap surgery) or a test group (reconstructive surgery using bone substitute material). Clinical assessments, including probing pocket depth (PPD), bleeding and suppuration on probing (BOP & SOP) as well as soft tissue recession (REC), were recorded at baseline, 6 and 12 months. Marginal bone levels (MBL), measured on intra-oral radiographs, and patient-reported outcomes (PROs) were recorded at baseline and 12 months. No blinding to group allocation was performed. The primary outcome at 12 months was a composite measure including (i) implant not lost, (ii) absence of BOP/SOP at all aspects, (iii) PPD ≤5 mm at all aspects and (iv) ≤1 mm recession of mucosal margin on the buccal aspect of the implant. Secondary outcomes included (i) changes of MBL, (ii) changes of PPD, BOP%, and buccal KM, (iii) buccal REC and (iv) patient-reported outcomes. RESULTS: During follow-up, four implants (one in the test group, three in the control group) in four patients were removed due to disease progression. At 12 months, a total of 69 implants in the test and 68 implants in the control group were examined. Thus, 16.4% and 13.5% of implants in the test and control group, respectively, met all predefined criteria of the composite outcome. PPD reduction and MBL gain were 3.7 mm and about 1.0 mm in both groups. Reduction in mean BOP% varied between 45% (test) and 50% (control), without significant differences between groups. Buccal REC was less pronounced in the test group (M = 0.7, SD = 0.9 mm) when compared to controls (M = 1.1, SD = 1.5 mm). PROs were favorable in both groups without significant differences. One case of allergic reaction to the antibiotic therapy was recorded. No other adverse events were noted. CONCLUSIONS: Surgical therapy of peri-implantitis effectively improved the clinical and radiographic status at 12 months. While the use of a bone substitute material did not improve reductions of PPD and BOP, buccal REC was less pronounced in the test group. Patient satisfaction was high in both groups.

Buccal soft tissue dehiscence defects at dental implants-associated factors and frequency of occurrence: A systematic review and meta-analysis.

AIM: To identify the factors associated with buccal peri-implant soft tissue dehiscences (BSTDs) and their frequency of occurrence. MATERIALS AND METHODS: Randomized controlled trials, controlled clinical trials, cohort studies, and case series assessing the frequency of occurrence of BSTD were included. BSTD was defined as an apical migration of the peri-implant soft tissues of ≥1 mm from the baseline examination (final restoration) or in comparison with the adjacent or contralateral natural tooth. Frequency distributions of BSTD related to the presence or absence of any surgical, prosthetic, or anatomic factor that may have contributed to the development of BSTD were recorded. Random-effects meta-analyses using odds ratios (OR) were performed to investigate the association of certain factors with the development of BSTD. RESULTS: Twenty-four articles were finally included belonging to 22 clinical investigations. Patients at higher risk of developing BSTD were associated with thin biotype (OR = 2.85 [1.40, 5.8], n = 5, p = .003) and with buccally placed implants (OR = 14.37 [4.58, 45.14], n = 3, p ≤ .001). Patients without connective tissue grafting (CTG) had greater odds of developing BSTD (OR = 9.00 [3.11, 26.02], n = 5, p ≤ .001), while buccal bone plate thickness of <1 mm and immediately placed implants were not associated with greater BSTD (OR = 1.29 [0.35, 4.77], n = 2, p = .704 and OR = 1.56 [0.46, 5.26], n = 4, p = .477, respectively). The frequency of occurrence of BSTD varied across the included studies with a range from 0% to 61%. CONCLUSIONS: Thin tissue biotype and buccally placed implants were associated with BSTD, whereas CTG seemed to have a protective effect. Thin buccal plates and immediately placed implants did not demonstrate a higher risk of BSTD.

Efficacy of keratinized mucosal augmentation with a collagen matrix concomitant to the surgical treatment of peri-implantitis: A dual-center randomized clinical trial.

AIM: The aim of this study was to evaluate the efficacy of a xenogeneic collagen matrix to augment the width of keratinized mucosa (KM), concomitantly to the surgical treatment of peri-implantitis, when compared to the use of an autologous soft tissue graft. MATERIAL AND METHODS: In this 12-month parallel-arm randomized controlled clinical trial, patients with peri-implantitis were randomly assigned, one month after non-surgical therapy, to surgical resective treatment of peri-implantitis consisting on an apically positioned flap (APF) in combination with a KM augmentation procedure, either with an autologous free gingival graft (FGG) or a collagen matrix (CM). Primary outcomes were the increase in the width of KM and probing pocket depth (PPD) reduction at 12 months. As secondary outcomes, peri-implant radiographic and patient-reported outcomes were assessed. RESULTS: The intention-to-treat population consisted of 49 subjects, assigned to either the APF + FGG (n = 23) or APF + CM (n = 26) group. PPDs were reduced by 1.6 mm (SD 1.0) and 1.7 mm (SD 1.2), respectively, being these differences non statistically significant (p = .782). However, the increase in KM was significantly higher in the APF + FGG compared with APF + CM (2.5 mm [SD 1.6] vs. 1.6 mm [SD 1.2], respectively (p = .033). CONCLUSION: The tested surgical modalities resulted in similar improvements of the clinical parameters. Both free gingival graft and collagen matrix significantly increased the peri-implant keratinized mucosa, but this KM gain was significantly higher with the free gingival graft. Use of CM, however, was better appreciated by the patients, in terms of pain perception and analgesic consumption, although the surgical time was similar.

Factors associated with the presence of peri-implant buccal soft tissue dehiscences: A case-control study.

BACKGROUND: To identify factors associated with the presence of buccal soft tissue dehiscences (BSTD). METHODS: This cross-sectional observational study assessed 52 cases (CAS) with a minimum of 24 months of loading, with the presence of a BSTD, defined as an exposure of the prosthetic abutment, the implant neck or the implant surface in the anterior maxillae or mandible (premolar-premolar) and 52 carefully selected controls (CON) matched for age and years in function, being the only difference between groups the BSTD. Clinical parameters and radiographic findings from periapical radiographs and Cone Beam Computed Tomographies (CBCT) were analyzed to assess their association with the occurrence of BSTD using a multivariate regression model. RESULTS: The CAS had a mean keratinzed mucosa (KM) of 1.65 ± 1.31 mm, whereas in the CON KM was 3.27 ± 1.28 mm (P = 0.001). Probing depths were similar in both groups, whereas bleeding on probing and plaque scores were higher in the CAS (P = 0.001). Mean bone level scores in the CAS were 1.71 ± 1.04 mm, and 1.27 ± 1.01 mm in CON (P = 0.143). The first bone to implant contact at the buccal aspect was 4.85 ± 3.12 mm in CAS and 2.15 ± 3.44 mm in CON (P = 0.001). CAS were 1.48 ± 0.93 mm outside the alveolar envelope, whereas the CON were 0.46 ± 0.77 mm. Implants buccally positioned in the CBCT's were 34 times more likely to belong to the case group. The presence of >2 mm of KM at the time of evaluation, presence of adjacent natural teeth, cemented restorations and two-piece implants were protective factors. CONCLUSION: The bucco-palatal implant position was the most relevant factor related to the presence of BSTD.

Efficacy of reconstructive surgical therapy at peri-implantitis-related bone defects. A systematic review and meta-analysis.

OBJECTIVES: The present systematic review aimed at evaluating the efficacy of reconstructive surgical therapy at peri-implantitis-related bone defects. METHODS: Studies reporting on outcomes of reconstructive surgery at peri-implantitis-related bone defects at 12 months were identified through an electronic search. Following data extraction, two different sets of meta-analyses were performed. Primarily, controlled studies were used to evaluate the potential benefit of reconstructive surgical therapy over controls. Secondly, overall outcome of reconstructive surgical therapy was assessed by comparing baseline values with outcomes at 12 months. Results were expressed as weighted mean differences (WMD) or risk ratios (RR). Heterogeneity was described by I2 and prediction intervals. RESULTS: The potential benefit of reconstructive techniques over control procedures was evaluated in three studies, representing a total of 116 implants. Altogether, 16 studies reported on the outcome of reconstructive measures at 12 months after surgery. The meta-analyses identified a larger improvement in marginal bone levels (MBL, WMD = 1.7 mm) and in defect fill (WMD = 57%) for test procedures, but found no differences for clinical measures (reduction of probing depth (PD) and bleeding on probing (BOP). Changes of clinical attachment and soft tissue levels were not considered. In terms of overall outcome, therapy resulted in improved MBL (WMD = 2.0 mm) and CAL (WMD = 1.8 mm), in recession (WMD = 0.7 mm), in reduced PD (WMD = 2.8 mm) and in reduced BOP (Implants: RR = 0.4/Sites: RR = 0.2). None of the included studies addressed patient-reported outcome measures. CONCLUSIONS: The available evidence on reconstructive therapy at peri-implantitis-related defects is limited by (a) the low number of controlled studies, (b) the lack of controlled studies for commonly used procedures, (c) the heterogeneity between studies and (d) the choice of outcome measures. A high variability for predicted outcomes at 12 months was noted. The interpretation of the demonstrated larger MBL gain for test procedures is difficult as graft material may not be distinguishable from newly formed bone. Potential aesthetic and patient-reported advantages remain to be demonstrated.