Repeated delivery of chlorhexidine chips for the treatment of periimplantitis: A multicenter, randomized, comparative clinical trial.

"This is the peer reviewed version of the following article:Machtei, EE, Romanos, G, Kang, P, et al. Repeated delivery of chlorhexidine chips for the treatment of periimplantitis: A multicenter, randomized, comparative clinical trial. J Periodontol. 2020; 1– 10. https://doi.org/10.1002/JPER.20-0353 which has been published in final form at doi: https://doi.org/10.1002/JPER.20-0353 . This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions."BACKGROUND: Periimplantitis is a challenging condition to manage and is frequently treated using non-surgical debridement. The local delivery of antimicrobial agents has demonstrated benefit in mild to moderate cases of periimplantitis. This study compared the safety and efficacy of Chlorhexidine gluconate 2.5 mg chip (CHX chips) as an adjunctive treatment to sub-gingival debridement in patients afflicted with periimplantitis. METHODS: A multi-center, randomized, single-blind, two-arm, parallel Phase-3 study was conducted. Periimplantitis patients with implant pocket depths (IPD) of 5-8 mm underwent sub-gingival implant surface debridement followed by repeated bi-weekly supra-gingival plaque removal and Chlorhexidine chips application (ChxC group) for 12 weeks, or similar therapy but without application of ChxC (control group). All patients were followed for 24 weeks. Plaque and gingival indices were measured at every visit while IPD, recession and bleeding on probing were assessed at 8,12,16,24 week. RESULTS: 290 patients were included: 146 in the ChxC group and 144 in the control. At 24 weeks, a significant reduction in IPD (p = 0.01) was measured in the ChxC group (1.76 ± 1.13 mm) compared to the control group (1.54 ± 1.13 mm). IPD reduction of ≥2 mm was found in 59% and 47.2% of the implants in the ChxC and control groups, respectively (p = 0.03). Changes in gingival recession (0.29 ± 0.68 mm vs. 0.15 ± 0.55 mm, p = 0.015) and relative attachment gain (1.47 ± 1.32 mm and 1.39 ± 1.27 mm, p = 0.0017) were significantly larger in the ChxC group. Patients in the ChxC group that were <65 years exhibited significantly better responses (p<0.02); likewise, non-smokers had similarly better response (p <0.02). Both protocols were well tolerated, and no severe treatment-related adverse events were recorded throughout the study. CONCLUSIONS: Patients with periimplantitis that were treated with an intensive treatment protocol of bi-weekly supra-gingival plaque removal and local application of Chlorhexidine chips had greater mean IPD reduction and greater percentile of sites with IPD reduction of ≥2 mm. as compared to bi-weekly supra-gingival plaque removal. (Clinicaltrials.gov NCT02080403). This article is protected by copyright. All rights reserved

In vitro evaluation of various bioabsorbable and nonresorbable barrier membranes for guided tissue regeneration

<p>Abstract</p> <p>Background</p> <p>Different types of bioabsorbable and nonresorbable membranes have been widely used for guided tissue regeneration (GTR) with its ultimate goal of regenerating lost periodontal structures. The purpose of the present study was to evaluate the biological effects of various bioabsorbable and nonresorbable membranes in cultures of primary human gingival fibroblasts (HGF), periodontal ligament fibroblasts (PDLF) and human osteoblast-like (HOB) cells <it>in vitro</it>.</p> <p>Methods</p> <p>Three commercially available collagen membranes [TutoDent^®(TD), Resodont^®(RD) and BioGide^®(BG)] as well as three nonresorbable polytetrafluoroethylene (PTFE) membranes [ACE (AC), Cytoplast^®(CT) and TefGen-FD^®(TG)] were tested. Cells plated on culture dishes (CD) served as positive controls. The effect of the barrier membranes on HGF, PDLF as well as HOB cells was assessed by the Alamar Blue fluorometric proliferation assay after 1, 2.5, 4, 24 and 48 h time periods. The structural and morphological properties of the membranes were evaluated by scanning electron microscopy (SEM).</p> <p>Results</p> <p>The results showed that of the six barriers tested, TD and RD demonstrated the highest rate of HGF proliferation at both earlier (1 h) and later (48 h) time periods (<it>P </it>< 0.001) compared to all other tested barriers and CD. Similarly, TD, RD and BG had significantly higher numbers of cells at all time periods when compared with the positive control in PDLF culture (<it>P </it>≤ 0.001). In HOB cell culture, the highest rate of cell proliferation was also calculated for TD at all time periods (<it>P </it>< 0.001). SEM observations demonstrated a microporous structure of all collagen membranes, with a compact top surface and a porous bottom surface, whereas the nonresorbable PTFE membranes demonstrated a homogenous structure with a symmetric dense skin layer.</p> <p>Conclusion</p> <p>Results from the present study suggested that GTR membrane materials, per se, may influence cell proliferation in the process of periodontal tissue/bone regeneration. Among the six membranes examined, the bioabsorbable membranes demonstrated to be more suitable to stimulate cellular proliferation compared to nonresorbable PTFE membranes.</p

Autophagy in periodontitis patients and gingival fibroblasts: unraveling the link between chronic diseases and inflammation

Authors are indebted with Ms Monica Glebocki for extensive editing of the manuscriptBackground: Periodontitis, the most prevalent chronic inflammatory disease, has been related to cardiovascular diseases. Autophagy provides a mechanism for the turnover of cellular organelles and proteins through a lysosome-dependent degradation pathway. The aim of this research was to study the role of autophagy in peripheral blood mononuclear cells from patients with periodontitis and gingival fibroblasts treated with a lipopolysaccharide of Porphyromonas gingivalis. Autophagy-dependent mechanisms have been proposed in the pathogenesis of inflammatory disorders and in other diseases related to periodontitis, such as cardiovascular disease and diabetes. Thus it is important to study the role of autophagy in the pathophysiology of periodontitis. Methods: Peripheral blood mononuclear cells from patients with periodontitis (n = 38) and without periodontitis (n = 20) were used to study autophagy. To investigate the mechanism of autophagy, we evaluated the influence of a lipopolysaccharide from P. gingivalis in human gingival fibroblasts, and autophagy was monitored morphologically and biochemically. Autophagosomes were observed by immunofluorescence and electron microscopy. Results: We found increased levels of autophagy gene expression and high levels of mitochondrial reactive oxygen species production in peripheral blood mononuclear cells from patients with periodontitis compared with controls. A significantly positive correlation between both was observed. In human gingival fibroblasts treated with lipopolysaccharide from P. gingivalis, there was an increase of protein and transcript of autophagy-related protein 12 (ATG12) and microtubule-associated protein 1 light chain 3 alpha LC3. A reduction of mitochondrial reactive oxygen species induced a decrease in autophagy whereas inhibition of autophagy in infected cells increased apoptosis, showing the protective role of autophagy. Conclusion: Results from the present study suggest that autophagy is an important and shared mechanism in other conditions related to inflammation or alterations of the immune system, such as periodontiti

Methodological issues in epidemiological studies of periodontitis - how can it be improved?

Background: This position paper was commissioned by the European Association of Dental Public Health, which has established six working groups to investigate the current status of six topics related to oral public health. One of these areas is epidemiology of periodontal diseases. Methods: Two theses "A systematic review of definitions of periodontitis and the methods that have been used to identify periodontitis" [1] and "Factors affecting community oral health care needs and provision" [2] formed the starting point for this position paper. Additional relevant and more recent publications were retrieved through a MEDLINE search. Results: The literature reveals a distinct lack of consensus and uniformity in the definition of periodontitis within epidemiological studies. There are also numerous differences in the methods used. The consequence is that data from studies using differing case definitions and differing survey methods are not easily interpretable or comparable. The limitations of the widely used Community Periodontal Index of Treatment Need (CPITN) and its more recent derivatives are widely recognized. Against this background, this position paper reviews the current evidence base, outlines existing problems and suggests how epidemiology of periodontal diseases may be improved. Conclusions: The remit of this working group was to review and discuss the existing evidence base of epidemiology of periodontal diseases and to identify future areas of work to further enhance it