Effects of antimicrobial mouthwashes on the human oral microbiome: Systematic review of controlled clinical trials.

OBJECTIVES: This review aimed to assess the impact of mouthwashes on the composition of the human oral microbiome. METHOD: An electronic search algorithm was adapted to MEDLINE-PubMed, Scopus, Embase and ISI Web of Science, and reference lists of relevant sources were manually searched. Inclusion criteria were controlled clinical trials published in English whose population were adult individuals who rinse with antimicrobial mouthwashes and that analysed changes in the oral microbiome by metataxonomy, metagenomics or phylogenetic microarray. Identified studies were screened and assessed following the PRISMA guidelines, and results were compiled into qualitative synthesis of the evidence. RESULTS: Five controlled clinical studies were included. These studies found associations between the daily use of mouthwashes and changes in the oral microbiome, but the nature of the effect varied according to the mouthwash. Chlorhexidine (CHX) rinses lowered microbial diversity. While 7-day use of CHX led to increases in the abundance of Neisseria, Streptococcus and Granulicatella and a decrease in the abundance of Actinomyces, its prolonged use led to widespread reductions in several genera and species. Cetylpyridinium chloride-containing mouthwashes specifically lowered the abundance of gingivitis-associated genera. In contrast, N-acetyl cysteine-based mouthwashes did not promote changes in the oral microbiome. CONCLUSIONS: Despite substantial heterogeneity, we found evidence to support the hypothesis that CHX and CPC mouthwashes promote changes in oral microbial structure and/or reductions in community diversity that favour the resolution of dysbiosis. However, future large population-based studies of adequate duration are needed to fully understand the extent to which antimicrobial mouthwashes modulate the microbiome.

Alterations in macrophage polarization play a key role in control and development of periodontal diseases.

Periodontitis is a chronic inflammatory disease driven by complex interplays between a dysbiotic oral microbiome and a dysregulated host inflammatory response that results in the destruction of the tooth-supporting apparatus. Among the inflammatory cells involved in the pathogenesis of periodontitis, macrophages are recruited early on to sites of periodontal infection. These cells can polarize in different phenotypes that mediate the initiation and resolution of inflammatory responses, as well as in tissue healing. Macrophage phenotypic plasticity is thought to play a critical role in the induction and resolution of inflammation and may be compromised in patients with chronic inflammatory diseases. Here, we reviewed the role of macrophage polarization in periodontal disease and therapy.

Efficacy of stem cells on bone consolidation of distraction osteogenesis in animal models: a systematic review.

Distraction osteogenesis (DO) relies on the recruitment and proliferation of mesenchymal stem cells (MSC) to the target site, where they differentiate into osteoblasts to promote bone formation. Nevertheless, MSC recruitment appears to be slow and limits bone formation in DO defects. Thus, this systematic review aims to evaluate the ability of locally applied MSC to enhance bone formation in DO preclinical models. Databases were searched for quantitative pre-clinical controlled studies that evaluated the effect of local administration of MSC on DO bone formation. Eligible studies were identified and data regarding study characteristics, outcome measures and quality were extracted. Nine studies met the inclusion criteria. Autogenous and xenogenous MSC were used to promote DO bone formation. These included bone marrow-derived MSC, adipose tissue-derived MSC and MSC derived from human exfoliated deciduous teeth. Meta-analysis was not possible due to heterogeneities in study designs. Local MSC implantation was not associated with adverse effects. In 4 out of the 5 studies, locally delivered undifferentiated bone-marrow MSC had a positive effect on DO bone formation. Few studies evaluated the therapeutic effects of MSC from other sources. The adjunct use of biologically active molecules or forced expression of key genes involved in osteogenesis further boosted the ability of bone-marrow MSC to promote DO bone formation. While risk of bias and heterogeneity limited the strength of this systematic review, our results suggest that the use of MSC is safe and may provide beneficial effects on DO bone formation.

Efficacy of stem cells on bone consolidation of distraction osteogenesis in animal models: a systematic review

Abstract Distraction osteogenesis (DO) relies on the recruitment and proliferation of mesenchymal stem cells (MSC) to the target site, where they differentiate into osteoblasts to promote bone formation. Nevertheless, MSC recruitment appears to be slow and limits bone formation in DO defects. Thus, this systematic review aims to evaluate the ability of locally applied MSC to enhance bone formation in DO preclinical models. Databases were searched for quantitative pre-clinical controlled studies that evaluated the effect of local administration of MSC on DO bone formation. Eligible studies were identified and data regarding study characteristics, outcome measures and quality were extracted. Nine studies met the inclusion criteria. Autogenous and xenogenous MSC were used to promote DO bone formation. These included bone marrow-derived MSC, adipose tissue-derived MSC and MSC derived from human exfoliated deciduous teeth. Meta-analysis was not possible due to heterogeneities in study designs. Local MSC implantation was not associated with adverse effects. In 4 out of the 5 studies, locally delivered undifferentiated bone-marrow MSC had a positive effect on DO bone formation. Few studies evaluated the therapeutic effects of MSC from other sources. The adjunct use of biologically active molecules or forced expression of key genes involved in osteogenesis further boosted the ability of bone-marrow MSC to promote DO bone formation. While risk of bias and heterogeneity limited the strength of this systematic review, our results suggest that the use of MSC is safe and may provide beneficial effects on DO bone formation.