Adjuvant effects of Saccharomyces cerevisiae in the treatment of experimental periodontitis in rats undergoing chemotherapy

Abstract Surgical procedures, radiotherapy, and chemotherapy, individually or in association, are current oncological treatments. Among the most used chemotherapy drugs, 5-fluorouracil (5FU) is an antimetabolite with a broad spectrum of action. This study evaluated the effects of probiotics (PRO) as an adjuvant to the treatment of experimental periodontitis (EP) in rats immunosuppressed with 5FU. Methodology 108 rats were randomly allocated to six different groups: EP; SS - systemic treatment with saline solution (SS); 5FU - systemic treatment with 5FU; 5FU+PRO - systemic treatment with 5FU, followed by the local administration of Saccharomyces cerevisiae ; 5FU+SRP - systemic treatment with 5-FU, followed by scaling and root planing (SRP); and 5FU+SRP+PRO - systemic treatment with 5FU followed by local treatments with SRP and PRO. Immunosuppression was obtained at two points: at the time of ligature installation and after 48 h. Six animals from each group were euthanized at seven, 15, and 30 d and hemimandibles were collected and processed for histopathological, histometric, and immunohistochemical analysis. Data were subjected to statistical analysis (α=5%). Results At 7 d, the 5FU+PRO group showed less bone resorption and better structured connective tissue compared with the EP, SS, 5FU+SRP, and 5FU+SRP+PRO groups. At 15 d, the 5FU+SRP group showed a greater intensity of the inflammatory response (p<0.05). At 30 d, the 5FU+SRP+PRO group showed better structured bone tissue and a higher percentage of bone tissue (PBT) than the EP, SS, 5FU, and 5FU+PRO groups (p<0.05). Conclusion The use of Saccharomyces cerevisiae as monotherapy or as an adjuvant to periodontal therapy may have a positive effect on bone repair in immunosuppressed conditions.

Comparação da expansão óssea promovida pela técnica de osseodensificação com dois tipos de conjunto de fresas / Comparison of bone expansion promoted by the osseodensification technique with two types of drill sets

Introdução: A estabilidade primária é um importante indicador de sucesso da osseointegração. Porém, fatores locais com osso de baixa intensidade podem interferir negativamente na obtenção da estabilidade primária. Objetivo: O presente estudo avaliou o efeito de diferentes direções, velocidades de rotação e sistemas de fresagem na expansão de perfurações e estabilidade de implantes instalados em blocos mimetizando osso do tipo IV. Material e método: Foram instalados 50 implantes em blocos de poliuretano sólido rígido. Esses implantes foram igualmente divididos em cinco grupos (n = 10): 1) Fresa Maximus (utilizadas no sentido horário a 1200rpm); 2) Fresa Maximus (utilizadas no sentido horário a 600rpm); 3) Fresa Neodent (utilizadas no sentido horário a 800rpm); 4) Fresa Neodent (utilizadas no sentido anti-horário a 800rpm); 5) Fresa Neodent (utilizadas no sentido anti-horário a 600rpm). Foram executadas análises de estabilidade dos implantes através de testes de torque de inserção e remoção, além das análises de frequência de ressonância. Adicionalmente, a expansão associada às perfurações promovida pelas brocas foi avaliada por meio de análises tomográficas. Resultado: Verificou-se que os implantes instalados após o preparo da perfuração com as brocas Maximus a 600rpm apresentaram valores de torque de inserção maiores, quando comparados ao grupo de implantes instalados em perfurações confeccionadas com brocas Neodent. Ademais, as brocas Maximus apresentaram valores de expansão maiores que as brocas Neodent. Conclusão: As brocas Maximus são mais eficientes em promover a osseodensificação, e sua utilização está associada ao aumento da estabilidade dos implantes instalados em blocos mimetizando osso do tipo IV.

Introduction: Primary stability is an important indicator to obtain a successful osseointegration. However, local factors like bone with low density can negatively interfere in obtaining primary stability. Objective: This study assessed the effect of different drilling systems, speeds, and movement directions on the expansion of perforations and the stability of implants placed in blocks that mimicked type IV bone. Material and method: Fifty implants were installed in rigid solid polyurethane blocks and equally divided into the following five groups (n = 10): 1) Maximus Driller (on a clockwise direction at 1200rpm); 2) Maximus Driller (on a clockwise direction at 600rpm); 3) Neodent Driller (on a clockwise direction at 800rpm); 4) Neodent Driller (on a counter clockwise direction at 800rpm); 5) Neodent Driller (on a counter clockwise direction at 600rpm). The stability analyses of the implants were performed through insertion and removal torque testing, in addition to resonance frequency analysis. Additionally, the expansion promoted by the drills associated with the perforations was assessed through tomographic analysis. Result: We found that implants placed after drilling preparation with Maximus drills at 600 rpm had higher values of insertion torque than the group of implants installed in drillings made with Neodent drills. In addition, the maximus drills showed higher expansion values than the Neodent drills. Conclusion Maximus drills are more efficient in promoting osseodensification and their use was associated with increased stability of implants installed in blocks that mimicked type IV bone.