Effects of alpha-tocopherol antioxidant on fracture strength and adhesion of endodontically treated teeth restored after dental bleaching.

This study evaluated the effect of different concentrations of alpha-tocopherol in gel form on fracture strength, hybrid layer formation, and microtensile bond strength of endodontically treated teeth bleached with 40% hydrogen peroxide (H2 O2 ). Sixty bovine incisors were randomized into one of six groups (n = 10 incisors per group) defined by the interventions carried out after endodontic treatment. In the control group, no additional intervention was carried out, while all teeth in the five intervention groups were bleached with 40% H2 O2 and subsequently treated with alpha-tocopherol at concentrations of 15% (15AT), 20% (20AT), or 25% (25AT), with 10% sodium ascorbate (10SA), or with nothing (40HP). Fracture strength was evaluated in a mechanical testing machine, hybrid layer formation was assessed using scanning electron microscopy, and bond strength was determined using microtensile bond-strength testing. Data were analyzed using Kruskal-Wallis and Dunn's tests. No statistically significant difference regarding fracture strength was observed among groups. Hybrid layer formation was greater in the 15AT group than in groups 40HP and 10SA. Teeth in groups 15AT, 20AT, and 25AT demonstrated higher bond strength than teeth in groups 40HP and 10SA. Alpha-tocopherol, preferably at 15%, effectively reverses the deleterious effects, of bleaching, on hybrid layer formation and bond strength to dentin.

Role of testosterone and androgen receptor in periodontal disease progression in female rats.

BACKGROUND: Sex hormone therapy has strict recommendations in the treatment of postmenopausal symptoms, in which testosterone (TES) replacement may play a potential role. However, it remains unclear whether TES affects the course of chronic inflammation and alveolar bone loss in females. Herein, we investigated the role of androgen receptor and TES on the inflammatory response and alveolar bone resorption associated with ligature-induced periodontal disease in female rats. METHODS: Fifty female Holtzman rats were divided in five groups (n = 10/group): androgen receptor antagonist (flutamide); estrogen receptor antagonist (fulvestrant); TES supplementation; aromatase inhibitor (anastrozole); and TES plus anastrozole. Periodontitis was induced by ligatures around the lower first molars for 2 weeks. Twenty animals (n = 10/group) were used as untreated ligated or non-ligated controls. Bone loss and the number of osteoclasts were measured through radiographic and immunohistochemical analysis, respectively. Inflammatory cytokines, chemokines and bone markers were measured by multiplex immunoassay and ELISA in serum samples and periodontal tissues. RESULTS: The blockage of androgen receptor significantly increased radiographic bone loss and tissue levels of IL-1α (P <0.05), IL-1ß (P <0.001) and IL-10 (P <0.01) compared with the periodontitis group. Testosterone supplementation significantly increased EGF levels in tissue samples, whereas when combined with aromatase inhibitor anastrozole significantly increased both EGF and VEGF (P <0.05). None of the treatment conditions significantly impacted the number of osteoclasts compared with the periodontitis group. CONCLUSIONS: Androgen receptor activation is an important factor in the regulation of several inflammatory markers, and its blockage significantly increases bone loss.

Anatomia aplicada às técnicas cirúrgicas periodontais / Anatomy applied to periodontal surgical techniques: a literature review

Em algumas situações clínicas, durante o tratamento da doença periodontal ou de defeitos relacionados à posição, quantidade e espessura dos tecidos gengivais, se faz necessária a aplicação de técnicas cirúrgicas para intervenção terapêutica dessas diferentes condições. Porém, para a correta execução desses procedimentos, o conhecimento anatômico se faz extremamente necessário, pois, em algumas situações, estruturas nobres podem estar presentes na área de intervenção cirúrgica. Dessa forma, o objetivo deste estudo foi realizar uma revisão das estruturas anatômicas da cavidade oral que podem interferir na aplicação de técnicas cirúrgicas periodontais. Dentre os procedimentos cirúrgicos praticados em Periodontia, os retalhos, os enxertos e a cirurgia de cunha distal são os mais críticos para a possível lesão de estruturas nobres. Estruturas vasculares, nervos e ductos de glândulas salivares encontram-se associados às regiões próximas da gengiva inserida, que é a área de interesse em uma abordagem cirúrgica periodontal. Dessa forma, o completo conhecimento da presença e localização dessas estruturas auxilia na prevenção de acidentes cirúrgicos durante a cirurgia periodontal.

In some clinical situation during the periodontitis treatment and/or morphological mucogingival defect treatment related with the position, size and thickness of the gingival tissue, the application of surgical techniques for treating these different conditions is necessary. However, for the correct execution of these procedures, the anatomical knowledge of structures is necessary due the fact that in some situations noble structures may be present in the surgical field. Thus, the aim of this study was to review the anatomical structures of the oral cavity. That can interfere the periodontal surgery techniques. Among the surgical procedures practiced in Periodontics, the opening of flaps, grafts and distal wedge surgeries are the most critical for the possible injury to noble structures. Vessels, nerves, ducts of salivary glands are adjacent with regions of the attached gingiva, which is the area of interest in a periodontal surgical approach. Thus, the complete knowledge of the presence and location of these structures helps in preventing surgical accidents during periodontal surgery.