Several treatment modalities have been proposed to regenerate bone, including guided bone regeneration (GBR) where barrier membranes play an important role by isolating soft tissue and allowing bone to grow. Not all membranes biologically behave the same way, as they differ from their origin and structure, with reflections on their mechanical properties and on their clinical performance. Collagen membranes have been widely used in medicine and dentistry, because of their high biocompatibility and capability of promoting wound healing. Recently, collagen membranes have been applied in guided bone regeneration with comparable outcomes to non-resorbable membranes. Aim of this work is to provide a review on the main features, application, outcomes, and clinical employment of the different types of collagen membranes. Comparisons with non-resorbable membranes are clarified, characteristics of cross-linked collagen versus native collagen, use of different grafting materials and need for membrane fixation are explored in order to gain awareness of the indications and limits and to be able to choose the right membrane required by the clinical condition.

Background and objectives: Periodontitis is a multifactorial chronic inflammatory infectious disease in which an infection is necessary, but not sufficient, for development of the condition. Individual susceptibility strictly linked to the immune and inflammatory response of the organism must also be present. Low-grade inflammation (LGI) is a systemic status of chronic sub-clinical production of inflammatory factors. This condition represents a risk factor for many chronic diseases including diabetes, cardiovascular disease, cerebrovascular disease, neurodegenerative disease and cancer. This scoping review aims to clarify, summarize and disseminate current knowledge on the possible link between periodontitis, LGI and systemic health. Materials and Methods: PRISMA Extension for Scoping Reviews guidelines were followed. An ad-hoc created keyword string was used to search the electronic databases of PubMed/Medline, Embase, The Cochrane Library and ClinicalTrials.gov. A hand search of specialized journals and their reference lists was also performed. Results: 14 studies that respected eligibility criteria were selected and analyzed. There is emerging evidence of strong links between periodontitis, LGI and systemic health. On the one hand, periodontitis influences the systemic status of LGI and on the other hand, the systemic production of inflammatory factors affects periodontitis with a bidirectional connection. Conclusions: LGI and the subsequent onset of a systemic inflammatory phenotype can be considered the common substrate of many chronic inflammatory diseases including periodontitis, with multiple mutual connections between them. Understanding of the biological principles and mechanisms underlying such a complex interrelationship could lead to significant improvements in the field of personalized diagnostics and therapeutic protocols.

Background: The main therapeutic approach for periodontal diseases is mechanical treatment of root surfaces via scaling and root planing (SRP). Multicenter clinical trials have demonstrated that the adjunctive use of a chlorhexidine (CHX) chip is effective in improving clinical results compared to SRP alone. However, some recent studies failed to confirm these clinical results, and conflicting results were reported regarding the effects of the CHX chip on subgingival microflora. The aim of this study was to provide further data on the clinical and microbiologic effects of CHX chips when used as an adjunct to SRP.Methods: A total of 116 systemically healthy individuals with moderate to advanced periodontitis, aged 33 to 65 years, were recruited from the Departments of Periodontology of four Italian universities. For each subject, two experimental sites were chosen that had probing depths (PD) ≥5 mm and bleeding on probing (BOP) and were located in two symmetric quadrants. These two sites were randomized at the split‐mouth level, with one receiving SRP treatment alone and the other receiving treatment with SRP plus one CHX chip (SRP + CHX). PD, relative attachment level (RAL), and BOP were evaluated at baseline, prior to any treatment, and after 3 and 6 months. Supragingival plaque and the modified gingival index were evaluated at baseline and after 15 days and 1, 3, and 6 months. Subgingival microbiologic samples were harvested at baseline and after 15 days and 1, 3, and 6 months, cultured for total bacterial counts (TBCs), and investigated by polymerase chain reaction analysis for the identification of eight putative periodontopathogens.Results: When all of the pockets were considered, the PD and RAL were significantly less at 3 and 6 months compared to the baseline scores (P <0.01) for both treatments. Moreover, the PD was reduced in the SRP + CHX treatment group compared to the SRP treatment group at 3 and 6 months, whereas the RAL was similar for both treatments at 3 months and was reduced in the SRP + CHX treatment group at 6 months. The differences in PD reductions between the treatments were 0.30 and 0.55 mm at 3 and 6 months, respectively (P <0.01); for the RAL gain, the differences were 0.28 and 0.64 mm, respectively (P <0.001). The TBCs decreased significantly with both treatments. A similar, although less evident, pattern was noted when only the pockets with an initial PD ≥7 mm were considered. The percentage of sites positive for BOP was similar between the treatments at each time point. At 15 days and 1 month, the TBC for the SRP + CHX treatment group was significantly lower than for the SRP treatment group (P <0.01 and P <0.05, respectively). Over time, both treatments generally reduced the percentages of sites positive for the eight putative periodontopathic bacteria, although greater reductions were seen often for the SRP + CHX treatment group.Conclusions: The adjunctive use of the CHX chip resulted in a significant PD reduction and a clinical attachment gain compared to SRP alone. These results were concomitant with a significant benefit of SRP + CHX treatment on the subgingival microbiota.

Background: The aim of the present study was to assess the additional clinical benefit of autogenous cortical bone particulate (ACBP) when added to enamel matrix derivative (EMD), compared to EMD alone, in the treatment of deep periodontal intraosseous defects.Methods: A total of 28 intraosseous lesions in 27 patients with advanced periodontitis were included in this controlled clinical trial and randomly assigned to the EMD group (14 defects) or to the EMD + ACBP group (14 defects). Immediately before surgery (baseline) and after 6 and 12 months, probing depth (PD), clinical attachment level (CAL), and gingival recession (REC) were recorded. Radiographic depth of the defect (DEPTH) was also measured at baseline and 12 months post‐surgery.Results: At 6 and 12 months, PD and CAL significantly improved from baseline in both groups (P <0.000). No significant differences in terms of CAL gain and PD reduction were detected between groups. However, defect distribution according to CAL gain was significantly different between groups (P <0.05). DEPTH significantly decreased from baseline to 12 months in both groups (P <0.000); between‐group differences were not significant. At 12 months, a significantly greater REC increase in the EMD group (1.1 ± 0.7 mm) compared to the EMD + ACBP group (0.3 ± 0.8 mm) was observed (P <0.05).Conclusions: Both EMD and EMD + ACBP treatments led to a significant improvement in clinical and radiographic parameters at follow‐up with respect to presurgery condition. The combined approach resulted in reduced post‐surgery recession and increased proportion of defects with substantial CAL gain (≥6 mm).