In Vitro Physico-Chemical Characterization and Standardized In Vivo Evaluation of Biocompatibility of a New Synthetic Membrane for Guided Bone Regeneration.

This study's aim was to evaluate the biocompatibility and bioabsorption of a new membrane for guided bone regeneration (polylactic-co-glycolic acid associated with hydroxyapatite and ß-tricalcium phosphate) with three thicknesses (200, 500, and 700 µm) implanted in mice subcutaneously. Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and the quantification of carbon, hydrogen and nitrogen were used to characterize the physico-chemical properties. One hundred Balb-C mice were divided into 5 experimental groups: Group 1-Sham (without implantation); Group 2-200 µm; Group 3-500 µm; Group 4-700 µm; and Group 5-Pratix®. Each group was subdivided into four experimental periods (7, 30, 60 and 90 days). Samples were collected and processed for histological and histomorphometrical evaluation. The membranes showed no moderate or severe tissue reactions during the experimental periods studied. The 500-µm membrane showed no tissue reaction during any experimental period. The 200-µm membrane began to exhibit fragmentation after 30 days, while the 500-µm and 700-µm membranes began fragmentation at 90 days. All membranes studied were biocompatible and the 500 µm membrane showed the best results for absorption and tissue reaction, indicating its potential for clinical guided bone regeneration.

Clinical efficacy of xenogeneic collagen matrix in the treatment of gingival recession: a systematic review and meta-analysis.

Objective: The aim of this systematic review (SR) was to evaluate the effects of xenogenic collagen matrix (XCM) on the outcomes of clinical treatments of patients with Miller class-I or -II gingival recessions. Materials and methods: Articles that were published before March 2018 were electronically searched in four databases without any date or language restrictions and manually searched in regular journals and gray literature. The eligibility criteria comprised randomized controlled trials (RCTs) and prospective controlled trials with follow-up periods of 6 months or more that compared the performance of XCM in the treatment of Miller class-I or -II gingival recessions. This SR was registered in PROSPERO under number CRD42018106118. Results: Nine RCTs published between 2010 and 2018 were included in this SR. The percentage of root coverage (RC) was significantly higher (p = .0003) when gingival recessions were treated with XCM when compared to coronally advanced flap (CAF) alone. In addition, the parameters of keratinized mucosa width (KMW) (p = .006) and gingival thickness (GT) (p = .0003) were also improved when the XCM was used in comparison to the CAF alone. There was not a statistically significant difference (p = .22) between the clinical attachment level (CAL) achieved with the use of XCM and that achieved with CAF alone. RC with the use of XCM, when compared to connective tissue grafts (CTGs) (p = .09) and enamel matrix derivative (EMD) (p = .62), there was no significant difference; however, XCM yielded lower RC than CTG in the treatment of Miller class-I or -II gingival recessions. Conclusions: Based on both the individual studies' outcomes and the pooled estimates, it can be concluded that the use of XCM improves the RC, KMW and GT in the treatment of gingival recessions when compared to CAF alone and may be a viable alternative to use of CTG.