Impact of surface characteristics on the peri-implant microbiome in health and disease.

BACKGROUND: Because little is known about the impact of implant surface modifications on the peri-implant microbiome, we aimed to examine peri-implant communities in various surface types in order to better understand the impact of these surfaces on the development of peri-implantitis (PI). METHODS: One hundred and six systemically healthy individuals with anodized (AN), hydroxyapatite-coated (HA), or sandblasted acid-etched (SLA) implants that were >6 months in function were recruited and categorized into health (H) or PI. Peri-implant biofilm was analyzed using 16S rRNA gene sequencing and compared between health/disease and HA/SLA/AN using community-level and taxa-level metrics. RESULTS: Healthy implants did not demonstrate significant differences in clustering, alpha- or beta-diversity based on surface modification. AN and HA surfaces displayed significant differences between health and PI (p < 0.05); however, such a clustering was not evident with SLA (p > 0.05). AN and HA surfaces also differed in the magnitude and diversity of differences between health and PI. Six species belonging to the genera Shuttleworthia, Scardovia, and Prevotella demonstrated lower abundances in AN implants with PI, and 18 species belonging to the genera Fretibacterium, Tannerella, Treponema, and Fusobacterium were elevated, while in HA implants with PI, 20 species belonging to the genera Streptococcus, Lactobacillus, Veillonella, Rothia, and family Ruminococcaceae were depleted and Peptostreptococcaceae, Atopobiaceae, Veillonellaceae, Porphyromonadaceae, Desulfobulbaceae, and order Synergistales were enriched. CONCLUSIONS: Within the limitations of this study, we demonstrate that implant surface can differentially modify the disease-associated microbiome, suggesting that surface topography must be considered in the multi-factorial etiology of peri-implant diseases.

Stability of peri-implantitis surgical reconstructive therapy-a (> 2 years) follow-up of a randomized clinical trial.

OBJECTIVES: This follow-up study aimed to report the 24- and 30-month outcomes of a cohort previously enrolled in a randomized clinical trial on surgical reconstructive treatment of peri-implantitis. METHODS: Twenty-four patients were diagnosed with peri-implantitis and treated with surgical reconstructive therapy with or without the adjunctive use of Er:YAG laser. Within-group and between-group comparisons were tested with mixed model with repeated measures. RESULTS: Regarding peri-implant pocket depth (PPD) reduction (control vs. laser test group) between 6 months (- 1.85 vs. - 2.65 mm) and 30 months (- 1.84 vs. - 3.04 mm), the laser group showed statistically significant changes but not the control group. In terms of radiographic marginal bone loss (RMBL) at 6 months (- 1.1 vs. - 1.46 mm) to 24 months (- 1.96 vs. - 2.82 mm), both groups showed statistical difference compared to baseline. The six explanted implants all were featured by severe peri-implantitis and mostly with no or limited keratinized tissue (< 2 mm) at baseline and membrane exposure after surgery. Among the 15 retained cases, eight cases achieved more than 50% peri-implant bone level gain. CONCLUSIONS: Within the limitation and follow-up time frame of this trial, the outcome of the surgical reconstructive therapy sustained or improved in most of the cases. However, 25% of the implants with severe peri-implantitis failed 2 years after the surgical reconstructive therapy. The use of Er:YAG laser favors PPD reduction in the longer term up to 30 months. CLINICAL RELEVANCE: Longer-term follow-up on reconstructive therapy of peri-implantitis revealed sustained or improved stability in certain cases, but the survival of implants with severe peri-implantitis has its limitation, especially when there is limited keratinized tissue (< 2 mm or no KT). TRIAL REGISTRATION: Clinical Trials Registration Number: NCT03127228 and HUM00160290.

Impact of the periodontal phenotype in premolar and molar sites on bone loss following full-thickness mucoperiosteal flap: A 1-year prospective clinical trial.

BACKGROUND: Full-thickness mucoperiosteal flap (FTF) elevation could potentially affect the periodontium of the involved teeth; it is not clear if the periodontal phenotype of teeth involved in a FTF may influence these changes. The aim of this study was to evaluate the impact of FTF on teeth periodontium, as well as assessing the impact of periodontal phenotype on bone remodeling. METHODS: In this single arm prospective clinical trial, 26 subjects and a total of 52 adjacent teeth were included. Patients receiving implant surgery in the posterior area, at the time of implant site preparation, an FTF was extended one tooth mesial and distal to the planned site, and the flap was elevated both facially and lingually. Vertical and horizontal bone linear changes were measured on both adjacent teeth, using superimposed cone-beam computerized tomography (CBCT) images taken prior to implant placement (T0) and at 12 months (T1). Baseline digital scans of models and DICOM files were superimposed to assess the periodontal phenotype. RESULTS: Vertical bone changes from T0 to T1 were statistically significant (P = 0.013), with changes were significantly higher at the mesial (-0.31 ± 0.30 mm) and facial (P < 0.05) sites. Horizontal dimensional changes 5 mm subcrestally were similar among different locations (P = 0.086) and the bone width loss was higher closest to the crest (P = 0.001). No correlation was found between soft tissue thickness and bone changes. However, bone thickness at baseline appears to influence the extent of horizontal bone remodeling. Overall, the magnitude of bone loss either vertically or horizontally was clinically insignificant (≤0.4 mm). A preventive effect against bone loss maybe expected with bone thickness > 2 mm. CONCLUSION(S): Marginal bone changes in maxillary and mandibular posterior teeth following FTF at 12 months are very minimal, and mainly influenced by bone rather than soft tissue thickness. Overall, FTF does not seem to have deleterious effects on adjacent teeth periodontium.

Association between peri-implantitis and cardiovascular diseases: A case-control study.

BACKGROUND: This study assesses the association between peri-implantitis and cardiovascular diseases (CVD). METHODS: One hundred and twenty-eight patients with dental implants were recruited to evaluate the prevalence of peri-implantitis in patients with or without CVD (CVD group, n = 82, control group, n = 46, respectively). Diagnosis of peri-implantitis followed the 2017 World Workshop guidelines and the severity was defined as mild, moderate, and severe form when the radiographic bone loss (RBL) was <2, 2 to 4, and >4 mm. Multivariable logistic regression was performed to test the association between two diseases. RESULTS: A trend of higher prevalence of peri-implantitis defined by detectable RBL beyond the physiologic bone remodeling was found in the CVD group (64.6%) when compared with the controls (56.5%). A significant higher prevalence (48.8%) of moderate to severe peri-implantitis was identified in CVD compared with controls(30.4%) with a significant crude association between moderate to severe peri-implantitis and CVD (odds ratio = 2.18, 95% CI, 1.02 to 4.67; P = 0.04). The CVD group had a trend of higher prevalence of deep pockets (≥7 mm) and higher numbers of sites with bleeding on probing  (>66%) when compared with controls (P > 0.05). However, after controlling for multiple confounders including age, hypertension, smoking, family history of heart attack, and periodontitis, the significant association was not found. CONCLUSIONS: CVD group had significantly higher prevalence of moderate to severe peri-implantitis (RBL ≥2 mm). The association between the two diseases did not exist after controlling multiple confounders for CVD. Future studies with a larger sample size controlling for the patient- and implant-related confounders are needed to better understand the link between peri-implantitis and CVD.

Ultrasonographic evaluation of edentulous crestal bone topography: A proof-of-principle retrospective study.

OBJECTIVE: Edentulous crestal bone ridge assessment, an essential task for planning of implant and bone regenerative procedures, is performed through radiographs. Ultrasonography, providing point of care and cross-sectional images without radiation, could be an adjunct for this purpose. The aim was to investigate the feasibility of ultrasound (US) in assessing bone ridge width (BRW) and crestal bone surface quality (CBSQ) compared with cone beam computed tomography (CBCT). STUDY DESIGN: Records of patients who were planned for implant placement in at least 1 healed edentulous ridge space with available CBCT and US images were included. The BRWs at 1, 2, and 3 mm from the crest were measured and compared. The CBSQ agreement evaluated using a 3-tier grading system was calculated. RESULTS: A total of 45 sites were included. The mean correlation of BRW was 0.97. The mean BRW differences ranged from 0.048 mm (95% confidence interval, -0.69 to 0.78 mm) at the 1-mm level to 0.18 mm (95% confidence interval, -0.92 to 1.3 mm) at the 3-mm level. There was a 91% agreement in CBSQ between the 2 methods. CONCLUSIONS: Preliminary data with a limited clinical sample size suggested that US is feasible in evaluating crestal BRW and surface quality assessment compared with CBCT.

Impact of mucosal phenotype on marginal bone levels around tissue level implants: A prospective controlled trial.

BACKGROUND: The aim of this 1-year prospective clinical trial was to compare clinical parameters and marginal bone levels (MBLs) around tissue level implants with a partially smooth collar between patients with thin (≤2 mm) and thick (>2 mm) vertical mucosal phenotypes. METHODS: Thirty patients needing a single dental implant were recruited and allocated to thin (n = 14) or thick (n = 16) phenotype groups. Post-restoration, clinical (probing depth, recession, width of keratinized mucosa, bleeding on probing, suppuration, implant mobility, plaque index, and gingival index) and radiographic bone level measurements were recorded at different timepoints for 1 year. RESULTS: Twenty-six patients (13 per group) completed the 1-year examination. No implants were lost (100% survival rate). There were no significant differences (P >0.05) between thin and thick vertical mucosal phenotypes for any clinical parameter or for the radiographic MBL. CONCLUSIONS: Tissue level implants at 1 year of function placed in thin vertical mucosa achieved similar clinical parameters and radiographic MBLs as those in thick tissue. The formation of the peri-implant supracrestal tissue height plays a key role in MBL than mucosal thickness in tissue level implant.