Mechanical Properties of the Mandible in Postmenopausal Women Under Aledronate Treatment.

AIMS: This study evaluated the mechanical properties of mandibular bone tissue retrieved from postmenopausal women under alendronate treatment. METHODS: Twenty postmenopausal women were divided into two groups: healthy postmenopausal subjects (control group) and osteoporotic subjects treated with alendronate (alendronate group). Mandibular bone samples were retrieved with a trephine bur at the time of dental implant placement and fixed in 4% formalin. Samples were processed for hard tissue histology, and the bone surface was analyzed for nanohardness measurement. Nanohardness and elastic modulus were evaluated by using a Berkovich tip with elastic modulus of 1.016x106 MPa, Poisson coefficient of 0.3, and a load of 100 mN. Each cycle was configured with a load time of 18 seconds (speed of 1 mN/second), the discharge time of 18 seconds, and a rest time of 5 seconds during indentation at a depth of 10 µm. RESULTS: The control group presented the highest values for nanohardness and elastic modulus (p less than 0.05) in relation to the osteoporotic subjects. CONCLUSIONS: Within the limitations of the study, it can be concluded that treatment with alendronate negatively influenced the mechanical properties of mandibular bone in postmenopausal women by reducing bone nanohardness and elastic modulus.

Estudo da variação da permeabilidade, limpeza e contaminação do sistema de canais radiculares, após o preparo químico-cirúrgico e aplicação de laser de alta intensidade / Study of the variation of permeability, cleaning and contamination of the root canal system after preparation and application of high-intensity

A importância do aumento da permeabilidade e da limpeza da dentina radicular está ligada à melhora da sanificação e obturação do sistema de canais radiculares...

The permeability increasing and the cleanliness of root dentin walls are important to improve the sanitization and root canal filling. Thus, this study aimed to evaluate the variations of root dentin permebility of human teeth, after endodontic preparation followed by Er:YAG and Nd:YAG laser irradiation, using free Technetium-99m radioisotope (99mTc) as tracer. Additionally, SEM images were analyzed to evaluate the cleanliness of dentin walls and possible bacterial adhesion after Enterococcus faecalis inoculation...