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.

We previously generated induced pluripotent stem (iPS) cells from human dental pulp cells of deciduous teeth. Neural crest cells (NCCs) play a vital role in the development of the oral and maxillofacial region. Therefore, NCCs represent a cell source for bone, cartilage, and tooth-related tissue engineering. In this study, we examined whether iPS cells are capable of differentiating into NCCs through modification of the human embryonic stem cell protocol. First, iPS cells were dissociated into single cells and then reaggregated in low-cell-adhesion plates with neural induction medium for 8 days in suspension culture to form neurospheres. The neurospheres were transferred to fibronectin-coated dishes and formed rosette structures. The migrated cells from the rosettes abundantly expressed NCC markers, as evidenced by real-time polymerase chain reaction, immunofluorescence, and flow cytometric analysis. Furthermore, the migrated cells exhibited the ability to differentiate into neural crest lineage cells in vitro. They also exhibited tissue-forming potential in vivo, differentiating into bone and cartilage. Collectively, the migrated cells had similar characteristics to those of NCCs. These results suggest that human dental pulp cell-derived iPS cells are capable of differentiating into NCCs. Therefore, iPS cell-derived NCCs represent cell sources for bone and cartilage tissue engineering.

The transplantation of dedifferentiated fat (DFAT) cells in combination with poly(d,l-lactic-co-glycolic acid) (PLGA) scaffolds has previously been proven as an effective approach in promoting periodontal tissue regeneration in a rat fenestration defect model. The aim of this study was to assess the regenerative potential of DFAT cells in a rat model of three-wall periodontal bone defect. Three-wall bone defects were created bilaterally on the mesial side of rat maxillary first molars and were either left untreated or treated by implantation of PLGA scaffolds with DFAT cells or PLGA alone. Four weeks after surgery, the tissues were processed for micro-computed tomography (micro-CT) and histomorphometric examination. Micro-CT revealed that the PLGA/DFAT group had significantly higher rates of bone regeneration than the other groups, while histomorphometric analysis showed that the PLGA/DFAT group had significantly higher densities of collagen fiber bundles in acellular and cellular cementum than the PLGA group. Moreover, the results indicate that the placement of the PLGA scaffold prevented the downgrowth of the junctional epithelium. These findings suggest that DFAT cells contribute to tissue regeneration in three-wall periodontal defects, while PLGA provides space necessary for periodontal tissue restoration.

This microendoscopic technique proved to be useful for the treatment of lumbar foraminal stenosis.

We used microcomputed tomography(micro-CT) to evaluate the effects of basic fibroblast growth factor (FGF-2) contained in absorbable collagen sponges on angiogenesis and bone regeneration in rat calvarial non-critical-size bone defects. Two symmetrical non-critical-size calvarial bone defects (diameter, 2.7 mm) were created in male Fisher rats. An absorbable collagen sponge with or without FGF-2 (0.1% or 0.3%) was implanted into each defect. Blood vessel volume and bone volume were calculated using software. On day 28, blood vessel volume and bone volume were significantly greater in the 0.3% and 0.1% FGF-2 groups than in the control group. FGF-2 concentration-dependently increased blood vessels and bone formation in non-critical-size bone defects in rat calvaria. (J Oral Sci 56, 17-22, 2014)