Angiogenesis preceded bone regeneration around critical- and non-critical-sized calvarial bone defects. Angiogenesis led to full bone formation in non-critical-sized defects.

BackgroundMelatonin has many roles, including bone remodeling and osseointegration of dental implants. The topical application of melatonin facilitated bone regeneration in bone defects. We evaluated the effects of topical application of melatonin on vertical bone augmentation in rat calvaria secluded spaces.Material and MethodsIn total, 12 male Fischer rats were used and two plastic caps were fixed in the calvarium. One plastic cap was filled with melatonin powder and the other was left empty.ResultsNewly generated bone at bone defects and within the plastic caps was evaluated using micro-CT and histological sections. New bone regeneration within the plastic cap was increased significantly in the melatonin versus the control group.ConclusionsMelatonin promoted vertical bone regeneration in rat calvaria in the secluded space within the plastic cap. Key words:Melatonin, bone regeneration, bone defects, secluded space, rat calvarium.

ObjetivesThere have been several systematic reviews(SRs) on whether periodontal treatment for an individual with both periodontal disease and diabetes can improve diabetes outcomes. The purpose of this investigation was to conduct a systematic review (SR) of previous meta-analyses, and to assess the methodological quality of the SRs examining the effects of periodontal treatment and diabetes. (PROSPERO Registration # CRD 42015023470).Study DesignWe searched five electronic databases and identified previous meta-analyses of randomized controlled trials published through July 2015. In cases where the meta-analysis did not meet our criteria, the meta-analyses were recalculated. General characteristics of each included trial were abstracted, analyzed, and compared. The mean difference, 95% confidence intervals (CIs) and the I2 statistic were abstracted or recalculated. The Assessment of Multiple Systematic Reviews Instrument (AMSTAR) was used to assess methodological quality.ResultsOf the 475 citations screened, nine systematic reviews were included. In total, 13 meta-analyses included in nine SRs were examined. In comparability analyses, meta-analyses in four SRs did not meet our criteria, and were recalcuated. Of these 13 meta-analyses, 10 suggested significant effects of periodontal treatment on HbA1c improvement. Mean differences found in the 13 meta-analyses ranged from -0.93 to 0.13. AMSTAR assessment revealed six SRs with moderate and three with high overall quality.ConclusionsWe can conclude that there is a significant effect of periodontal treatment on improvement of HbA1c in diabetes patients, although the effect size is extremely small. In addition to the small effect size, not all SRs could be considered of high quality. Key words:Periodontal treatment, diabetes, HbA1c, systematic review, systematic review of systematic reviews, evidence-based medicine, AMSTAR.

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Background and Objectives The purpose of the present study was to evaluate the methodological quality and risk of bias in systematic reviews (SRs) on the effectiveness of peri‐implantitis treatments. Material and Methods We searched four electronic databases: MEDLINE, Web of Science, Cochrane Database of Systematic Reviews, and EMBASE. Previous SRs focusing on peri‐implantitis treatment published between 2010 and 2017 were identified. After literature screening, eligible SRs were qualitatively assessed using two validated instruments: Assessing the Methodological Quality of Systematic Reviews (AMSTAR2) and Risk Of Bias In Systematic reviews (ROBIS). The characteristics and findings of SRs are also reported. Results A total of 23 SRs formed the basis of this study. Of the 23, six included randomized controlled trials (RCTs) only. Overall, the AMSTAR2 assessment revealed three studies with high and six studies with low methodological quality, and all the other SRs were judged as having critically low methodological quality. ROBIS revealed only one Cochrane review with a low risk of bias and the others with a high risk of bias. In particular, the assessment of non‐randomized studies (NRSIs), appropriateness of ROB assessment, and meta‐analysis did not satisfy the criteria in AMSTAR2 assessment. Furthermore, there were a few SRs that interpreted and discussed the results of risk of bias (ROB) and heterogeneity assessment, together with the impact of treatment. Conclusions Due to the lack of head‐to‐head comparisons conducted in RCTs, review authors need to use other sources of evidence, such as clinical control trials (CCTs), cohort studies (CS), clinical research (CR), and animal studies. The end result is the presentation of low‐quality evidence, with high ROB. Several SRs conducted network meta‐analysis as an alternative to head‐to‐head conventional meta‐analysis of RCTs. We suggest that the best methods to generate, access, and assess evidence in situations where RCT evidence is lacking should be discussed on an urgent basis.

These results indicate that the higher the dose of intermittent PTH administered, the greater the amount of bone formation beyond the skeletal envelop in the rat calvarium.

Periodontitis caused by bacterialinfection gradually progresses accompanied by periodontal tissue destruction. As a result, teeth lose their supporting structures, and this leads to tooth exfoliation. CXC-chemokine receptor 4 (CXCR4) is known to be expressed in lymphocytes, fibroblasts and osteoclasts in periodontal tissues, suggesting that periodontal CXCR4 signaling contributes to alveolar bone resorption in the milieu of periodontitis. However, the role of CXCR4 signaling in the pathogenesis of periodontitis has remained unknown. We established a mouse model of periodontitis by inoculation of Porphyromonas gingivalis (P.g.) into a silk ligature placed around the maxillary molar. Although there was no significant difference in the mechanical sensitivity in the periodontal tissue between P.g. treatment and sham treatment during the experimental period, mechanical allodynia in the periodontal tissue was induced after gingival injection of complete Freund's adjuvant compared with that resulting from sham and P.g. treatment alone. Moreover, CXCR4 neutralization in the periodontal tissue following P.g. treatment enhanced periodontal inflammatory cell infiltration and depressed alveolar bone resorption. These findings suggest that periodontal CXCR4 signaling in several cell types in P.g.-induced periodontal inflammation depresses alveolar bone resorption in periodontitis. CXCR4 signaling might be a target for therapeutic intervention to prevent alveolar bone resorption in periodontitis.

Periodontitis is an inflammatory condition that causes the destruction of the supporting tissues of teeth and is a major public health problem affecting more than half of the adult population worldwide. Recently, members of the herpes virus family, such as the Epstein–Barr virus (EBV), have been suggested to be involved in the etiology of periodontitis because bacterial activity alone does not adequately explain the clinical characteristics of periodontitis. However, the role of EBV in the etiology of periodontitis is unknown. This study aimed to examine the effect of inactivated EBV on the expression of inflammatory cytokines in human gingival fibroblasts (HGFs) and the induction of osteoclast differentiation. We found that extremely high levels of interleukin (IL)-6 and IL-8 were induced by inactivated EBV in a copy-dependent manner in HGFs. The levels of IL-6 and IL-8 in HGFs were higher when the cells were treated with EBV than when treated with lipopolysaccharide and lipoteichoic acid. EBV induced IκBα degradation, NF-κB transcription, and RAW264.7 cell differentiation into osteoclast-like cells. These findings suggest that even without infecting the cells, EBV contributes to inflammatory cytokine production and osteoclast differentiation by contact with oral cells or macrophage lineage, resulting in periodontitis onset and progression.