Effects of Bdellovibrio bacteriovorus HD100 on experimental periodontitis in rats.

AIM: The aim of this study was to evaluate the effects of Bdellovibrio bacteriovorus HD100 on experimental periodontitis (EP) in rats. METHODS: Thirty-two rats were divided into four groups: control, C-HD100 (B. bacteriovorus), EP, and EP-HD100. On day 0, EP was induced by the placement of cotton ligatures around the mandibular first molars (MFMs) in the EP and EP-HD100 groups. In the C-HD100 and EP-HD100 groups, suspensions containing 1 × 109  PUF/ml of B. bacteriovorus HD100 were topically administered to the subgingival region of MFMs on days 0, 3, and 7. Animals were euthanized on day 14. Morphometrics analyses were performed in hemimandibles. The levels of tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, monocyte chemoattractant protein (MCP)-1, IL-10, IL-1ß, transforming growth factor beta (TGF-ß), macrophage colony-stimulating factor (M-CSF) and regulated on activation and normal T cell expressed and secreted (RANTES) were determined by enzymatic immunoassays in gingival tissues. Beta defensin (BD)-1, BD-2, and BD-3, Toll-like receptors (TLR)-2 and TLR-4, and a cluster of differentiation (CD)-4, CD-8 and CD-57 were analyzed by immunohistochemistry in hemimandibles. Data were statistically analyzed. RESULTS: The EP group showed greater alveolar bone loss than EP-HD100 (p < .05). The EP-HD100 group showed higher levels of MCP-1, RANTES, IL-10, and TGF-ß, lower levels of TNF-α than the EP group (p < .05). No differences were observed in IL-1ß, IL-6, and M-CSF levels between EP and EP-HD100 groups. The C-HD100 group had higher IL-6, TNF-α, RANTES, and MCP-1 levels than the control group (p < .05). Regarding BD, the EP-HD100 group showed a larger immunolabeling pattern for BD-1, BD-2, and BD-3 than the EP group (p < .05). No significant differences in the immunolabeling pattern were observed for TLR-2, TLR-4, CD-4, CD-8, and CD-57 between EP and EP-HD100 groups. CONCLUSION: The topical use of B. bacteriovorus HD100 reduces alveolar bone loss, increases expression of BD, and modulates the cytokines levels on periodontal tissues in rats with EP.

Effect of thermo-mechanical cycling and chlorhexidine on the bond strength of universal adhesive system to dentin.

OBJECTIVES: This study evaluated the influence of thermo-mechanical cycling (TMC) on the bond strength (BS) of a universal adhesive system (UAS - Adper Single Bond Universal, 3M ESPE) to dentin treated or not with 0.2% chlorhexidine (CHX). METHODS: Eighty human molars were flattened until reach the dentin and separated into 4 groups according to the bonding protocol: ENR Group: 37% phosphoric acid + 3-step etch-and-rinse adhesive system (ENR); UAS Group: UAS in self-etch mode; ENR + CHX Group: 37% phosphoric acid + CHX + ENR; UAS + CHX Group: CHX + UAS in self-etch mode. After treatments, teeth were restored (Filtek Z350, 3M ESPE). Samples (n = 10) were submitted to aging process: stored in distilled water at 37°C/30 days or TMC (ERIOS - 98N/1.6Hz + thermal cycling 5/37/55 °C - 1,200,000 cycles). Specimens were sectioned into sticks (1.0 mm2) and submitted to the microtensile test (Mechanical Test Machine - 0.5 mm/min). Fracture patterns and hybrid layer integrity were analyzed under Stereomicroscope and Scanning Electron Microscopy (SEM). RESULTS: The BS results (3-way ANOVA, Bonferroni's test, α = 5%) showed that groups treated with CHX presented higher BS values than control groups; significant in all cases (p < .05), except for ENR submitted to TMC (p > .05). When CHX was applied and samples were cycled, UAS revealed higher BS (p < .05) than ENR. After TMC, cohesive fractures increased for UAS, regardless of CHX application. SEM analysis demonstrated different hybridization patterns for the adhesive systems tested. CONCLUSION: The performance of the universal adhesive system used in self-etch mode was better than that of the 3-step etch-and-rinse adhesive system. CLINICAL SIGNIFICANCE: Universal adhesive systems have been developed in order to simplify the dentin hybridization protocol. It is important to determine the longevity of the adhesive interface using these bonding materials after chewing.

Uso da matriz derivada do esmalte (mde) associada ao vidro bioativo no tratamento de defeitos infra-ósseos: uma revisão de literatura / Use of enamel matrix derivate (EMD) associated with bioactive glass in the treatment of intraosseous defects: A Literature Review

A regeneração periodontal tem como objetivo recuperar as estruturas perdidas (osso alveolar, cemento e ligamento periodontal) como sequelas da doença periodontal. O conhecimento da Matriz Derivada do Esmalte (MDE) tem na literatura uma ampla aplicação, porém sua relação direta associada aos vidros bioativos é pouco caracterizada em todas suas vias, nesse contexto este estudo teve como proposta baseada numa revisão literária por meio de bases de dados (Pubmed, Scielo, lilacs), discutir aspectos importantes sobre a avaliação da efetividade clínica do vidro bioativo em combinação com a MDE (Emdogain) principalmente em defeitos infra-ósseos. O Emdogain (EMD) sozinho ou em associação a outros biomaterais de enxertia parece promover ganhos na regeneração tecidual de tecidos perdidos pela periodontite, porém sua associação tem-se poucos resultados significativos que justifiquem sua ampla utilização, sua indicação deve estar baseada em um bom diagnóstico periodontal e da morfologia do defeito infraósseo. Assim, tornam-se necessários mais estudos para elucidar interações e mecanismos celulares envolvidos no complexo de ação para justificar o seu uso.(AU)

Periodontal regeneration aims to recover the lost structures (alveolar bone, cementum and periodontal ligament) as sequelae of periodontal disease. The knowledge derived from the enamel matrix (EMD) is in the literature a wide application, but its direct relationship associated with bioactive glass is poorly characterized in all its way in this context this study was proposed based on a literature review through databases (Pubmed, Scielo, lilacs), discuss important aspects of the evaluation of the clinical effectiveness of bioactive glass in combination with EMD (Emdogain) mainly intraosseous defects.Emdogain (EMD) alone or in association with other biomaterials of grafting appears to promote gains in the tissue regeneration of lost tissues by periodontitis, but its association has few significant results that justify its wide use, its indication must be based on a good periodontal diagnosis and infraosseous defect morphology. Thus, further studies are needed to elucidate interactions and cellular mechanisms involved in the action complex to justify its use.(AU)