Survival and mechanical complications of single- and multiple-unit cement-retained posterior implant-supported restorations with custom CAD/CAM Atlantis titanium abutments: An up to 10-year retrospective analysis.

PURPOSE: To evaluate the survival of and incidence of mechanical complications with single- and multiple-unit cement-retained posterior implant-supported restorations with custom CAD/CAM Atlantis titanium abutments (Dentsply Sirona, Charlotte, NC, USA). MATERIALS AND METHODS: This retrospective clinical study analysed 196 Astra Tech OsseoSpeed TX Internal Hexagon implants (Dentsply Sirona) placed in 85 patients between January 2011 and January 2021. Customised Atlantis titanium abutments and cement-retained metal-ceramic crowns were employed. The clinical outcomes recorded were implant and abutment survival rates, and mechanical complications. The results were analysed according to implant length and diameter, arch, implant position and single- or multiple-unit restoration. RESULTS: Over the observation period (up to 10 years), implant and abutment survival rates were 98.5% and 100.0%, respectively. The mean observation period for the single- and multiple-unit implant-supported restorations was 106.00 ± 20.84 months, with a minimum of 41 months and a maximum of 120 months. For the 67 single-unit and 129 multiple-unit posterior implant-supported restorations, four mechanical complications were recorded: two cases of screw loosening, one case of chipping or fracture of veneering materials, and one case of crown decementation. No screw or abutment fractures were observed. CONCLUSIONS: According to the results of this retrospective clinical study, cement-retained posterior implant-supported restorations with custom CAD/CAM Atlantis titanium abutments showed high survival rates over a follow-up period of up to 10 years. No statistically significant differences were recorded when comparing implant position, implant diameter, implant length, single- versus multiple-unit restoration and arch.

Photo/mechanical and physical implant surface decontamination approaches in conjunction with surgical peri-implantitis treatment: A systematic review.

AIM: To evaluate the efficacy of adjunctive/alternative photo/mechanical and physical implant-surface decontamination approaches compared to standard instrumentation in conjunction with surgical peri-implantitis treatment. MATERIALS AND METHODS: Randomized controlled clinical trials (RCTs) and controlled clinical trials investigating the efficacy of adjunctive or alternative photo/mechanical/physical measures for implant surface decontamination in conjunction with surgical peri-implantitis treatment without (PICOS 1) or with (PICOS 2) additional decontamination methods performed in test and control groups with changing inflammation parameters were covered. Changes in bleeding scores (i.e., bleeding index, or bleeding on probing [BOP]), suppuration, and probing depth (PD) were considered the primary outcomes. RESULTS: Six articles describing five original RCTs were eligible for analysis. Based on two RCTs, the adjunctive/alternative use of air polishing with glycine or erythritol powder did not improve BOP reduction compared to standard instrumentation (PICOS 1). Based on one RCT, alternative use of titanium brushes resulted in significantly higher BOP reduction compared to either air polishing or standard instrumentation (PICOS 1). During reconstructive therapy and as an adjunct to implantoplasty, use of a titanium brush did not have any benefit on the BOP and mean PD reductions compared to the control group (i.e., implantoplasty + mechanical and chemical implant surface decontamination; one RCT; PICOS 2). Use of the Er:YAG laser resulted in significantly higher PD reduction after 6 months (one RCT), whereas no difference between the test and respective controls could be detected after 1 and 2 years (one RCT). Additionally, the use of the Er:YAG laser was not associated with improved BOP reductions over respective controls (two RCTs; PICOS 2). CONCLUSIONS: Owing to the limited available data, clinical efficacy of photo/mechanical and physical implant surface decontamination in conjunction with surgical peri-implantitis therapy is inconclusive. However, titanium brushes may be beneficial in reducing signs of inflammation.

The therapeutic potential of regulatory T lymphocytes in periodontitis: A systematic review.

This systematic review aimed to: (a) generate a descriptive synthesis of preclinical studies assessing the therapeutic potential of regulatory T lymphocytes (Tregs) to arrest periodontitis, (b) evaluate the methodological heterogeneity of the reviewed animal studies and (c) assess the risk of bias (RoB) of the included studies. The electronic search for animal studies included the MEDLINE, EMBASE, Web of Science and LILACS databases. In addition, a manual search assessed the high-ranked scientific journals in "periodontics/immunology" and the references listed in the included studies. There were no language, year or publication status restrictions. Two independent reviewers selected and extracted the data, and Cohen's Kappa coefficient was calculated to determine the inter-examiner agreement. The Systematic Review Center for Laboratory Animal Experimentation's (SYRCLE) tool was used to assess the RoB. A total of 21 of the 425 studies obtained from the database search were included. Treg function was mainly described in Porphyromonas gingivalis-induced periodontitis (57.1%) in mice (76.2%), where Treg suppression was strongly related to disease progression and Treg induction was strongly related to immuno-inflammatory response reduction. Of those 21 studies, eight included eight animal experiments using three distinct therapeutic approaches, including: P. gingivalis-driven immunization (n = 3), retinoic acid inoculation (n = 2) and anti-inflammatory molecules in polymeric carriers (n = 3), which could modulate the Treg activity through cytokine production (interleukin-10 and transforming growth factor-ß1), CC-chemokine- and CC-chemokine receptor-mediated chemoattraction (CCL22 and CCR4) or Th17-associated receptor activator of nuclear factor κB ligand (RANKL) downregulation. However, the studies with animal experiments did not specify the randomization sequences and housing conditions that were used, and therefore, 42.11% of the entries were rated as unclear RoB. Distinct therapeutic strategies involving Tregs could potentially suppress the immuno-inflammatory response and restore alveolar bone homeostasis during periodontitis. Nevertheless, important methodological variability, poor reporting of treatment effect estimates and unclear RoB suggest using caution when assessing the results of these studies.

Use of Biologic Agents to Promote Bone Formation in Implant Dentistry: A Critical Assessment of Systematic Reviews.

PURPOSE: The use of biologic agents is emerging in bone regeneration procedures due to their ability to increase cellular events in wound healing and therefore to obtain more predictable outcomes. Hence, the aim of the present study was to critically evaluate the methodology of systematic reviews investigating biologic agents in promoting bone formation and implant site development. MATERIALS AND METHODS: A literature search for systematic reviews with and without meta-analyses was performed in Medline, Embase, and the Cochrane database, as well as in journals with high impact factors in periodontics and implant dentistry. Titles, abstracts, and full-text articles were analyzed for potential inclusion. Three guidelines--AMSTAR, R-AMSTAR, and the checklist proposed by Glenny et al--were utilized to analyze their methodologic quality. Two calibrated reviewers performed all data extraction and appraisal. Cohen's kappa coefficients were calculated to appraise the interexaminer agreement. RESULTS: A total of 12 systematic reviews, 3 with meta-analyses, were evaluated. Platelet-rich derivatives and BMP-2 were the most widely studied biologic agents and sinus augmentation was the most common procedure evaluated. The R-AMSTAR mean score was 28 (range 14-38) and none of the systematic reviews analyzed met all of the items. In the AMSTAR checklist, the mean score was 5.75 (range 2-9) and the only item met by all the systematic reviews was the a priori design. The Glenny et al checklist mean score was 8.6 (range 4-13) and two items, "focused question" and "to identify all relevant studies," were met by all systematic reviews. CONCLUSION: Systematic reviews on biologic agents demonstrate substantial methodologic variability. Therefore, caution must be exercised when interpreting their findings.