EPA Consensus Project Paper: The Influence of Prosthetic Factors on the Incidence of Peri-implantitis Around Single Implants: A Systematic Review.

INTRODUCTION: The purpose of this systematic review was to evaluate how prosthetic factors affect the incidence of peri-implantitis in patients treated with single implant restorations. METHODS: Electronic and manual search of two indexed databases up to April 2023 were conducted, to identify clinical studies reporting on the effect of different prosthetic factors on the incidence of peri-implantitis around single implants and with at least 1 year follow-up. The risk of bias was assessed with the Joanna Briggs Institute critical appraisal checklist, the ROB2 and the ROBINS-I tools. RESULTS: From the 521 screened articles, 11 studies (1 randomized controlled trial, 7 cross-sectional, 3 retrospective) met the inclusion criteria. Based on three studies, emergence angle⟩30°, convex emergence profile and external connection are associated with a higher incidence of peri-implantitis. Nine studies pertaining to the effect of retention type on the prevalence of peri-implantitis reported conflicting results. Six out of eleven included studies presented some risk of bias. CONCLUSIONS: There is insufficient evidence regarding the influence of prosthetic factors on the incidence of peri-implantitis around single implants. Further studies are needed to draw definitive conclusions on this issue.

Evaluation of Monomer Elution and Surface Roughness of a Polymer-Infiltrated Ceramic Network CAD-CAM Material After Er,Cr:YSGG Laser-assisted Tooth Bleaching.

PURPOSE: The aim of this in vitro study was to examine the effect of Er,Cr:YSGG laser-assisted tooth bleaching treatment on the elution of monomers and surface roughness of a hybrid computer-aided design-computer-aided manufacturing (CAD-CAM) material, and to compare it with a resin composite for direct restorations. METHODS AND MATERIALS: Forty specimens of a hybrid CAD-CAM material (Enamic) and forty of a conventional resin composite (Tetric) were fabricated and randomly divided into four groups (n=10). Half of the specimens of each material were stored in distilled water and the other half in artificial saliva for 7 days. At the end of this period, the storage medium was analyzed by high-performance liquid chromatography (HPLC), and the surface roughness parameters of the specimens were evaluated by optical imaging noncontact interferometric profilometry. Afterwards, half of the specimens of each tested material received a conventional in-office tooth bleaching treatment and the other half an Er,Cr:YSGG laser-assisted bleaching treatment, and then they were again incubated in distilled water and artificial saliva for an additional 7-day time period. At the end of this period, the effect of the bleaching treatments on elution of monomers and surface roughness of the tested materials was evaluated. RESULTS: Bisphenol A (BPA), urethane dimethacrylate (UDMA), triethylene glycol dimethacrylate (TEGDMA), and bisphenol A-glycidyl dimethacrylate (BisGMA) were eluted from the conventional resin composite into both the solutions tested. Only TEGDMA was eluted from the hybrid CAD-CAM material. However, no statistically significant differences were found among the surface roughness parameters of both materials. Both the conventional and Er,Cr:YSGG laser-assisted tooth bleaching treatments affected the monomer elution from the composite resin. However, there were no statistically significant differences (p<0.05) between the treatments. CONCLUSIONS: According to the results of this study, tooth bleaching with Er,Cr:YSGG laser or conventional technique is safe, even if the bleaching agent comes in contact with hybrid CAD-CAM restorations.

The Influence of Smoking on the Peri-Implant Microbiome.

Smokers are at high risk for 2 bacterially driven oral diseases: peri-implant mucositis and peri-implantitis. Therefore, the purpose of this investigation was to use a deep-sequencing approach to identify the effect of smoking on the peri-implant microbiome in states of health and disease. Peri-implant biofilm samples were collected from 80 partially edentulous subjects with peri-implant health, peri-implant mucositis, and peri-implantitis. Bacterial DNA was isolated and 16S ribsomal RNA gene libraries sequenced using 454-pyrosequencing targeting the V1 to V3 and V7 to V9 regions. In total, 790,692 classifiable sequences were compared against the HOMD database for bacterial identification. Community-level comparisons were carried out using UniFrac and nonparametric tests. Microbial signatures of health in smokers exhibited lower diversity compared to nonsmokers, with significant enrichment for disease-associated species. Shifts from health to mucositis were accompanied by loss of several health-associated species, leading to a further decrease in diversity. Peri-implantitis did not differ significantly from mucositis in species richness or evenness. In nonsmokers, by contrast, the shift from health to mucositis resembled primary ecological succession, with acquisition of several species without replacement of pioneer organisms, thereby creating a significant increase in diversity. Again, few differences were detected between peri-implantitis and mucositis. Thus, our data suggest that smoking shapes the peri-implant microbiomes even in states of clinical health, by supporting a pathogen-rich community. In both smokers and nonsmokers, peri-implant mucositis appears to be a pivotal event in disease progression, creating high-at-risk-for-harm communities. However, ecological succession follows distinctly divergent pathways in smokers and nonsmokers, indicating a need for personalized therapeutics for control and prevention of disease in these 2 cohorts.

Patient-specific analysis of periodontal and peri-implant microbiomes.

Periodontally involved teeth have been implicated as 'microbial reservoirs' in the etiology of peri-implant diseases. Therefore, the purpose of this investigation was to use a deep-sequencing approach to identify the degree of congruence between adjacent peri-implant and periodontal microbiomes in states of health and disease. Subgingival and peri-implant biofilm samples were collected from 81 partially edentulous individuals with periodontal and peri-implant health and disease. Bacterial DNA was isolated, and the 16S rRNA gene was amplified and sequenced by pyrotag sequencing. Chimera-depleted sequences were compared against a locally hosted curated database for bacterial identification. Statistical significance was determined by paired Student's t tests between tooth-implant pairs. The 1.9 million sequences identified represented 523 species. Sixty percent of individuals shared less than 50% of all species between their periodontal and peri-implant biofilms, and 85% of individuals shared less than 8% of abundant species between tooth and implant. Additionally, the periodontal microbiome demonstrated significantly higher diversity than the implant, and distinct bacterial lineages were associated with health and disease in each ecosystem. Analysis of our data suggests that simple geographic proximity is not a sufficient determinant of colonization of topographically distinct niches, and that the peri-implant and periodontal microbiomes represent microbiologically distinct ecosystems.