Evaluation of factors related to the success of miniscrew-assisted rapid palatal expansion.

OBJECTIVES: To evaluate whether the success of miniscrew-assisted rapid palatal expansion (MARPE), performed in patients with advanced bone maturation is related to factors such as midpalatal suture (MPS) maturation, age, sex, or bicortical mini-implant anchorage. MATERIALS AND METHODS: Twenty-eight cone beam computed tomography (CBCT) scans of adults and post-pubertal adolescents treated by MARPE were included in the sample. CBCT images before (T0) and after expansion (T1) were used to evaluate the skeletal changes and the success or failure of MARPE. Axial images of MPS were extracted from T0 and classified into one of the five maturation stages. The correlation between MARPE success and the factors of age, sex, MPS maturation, and bicortical mini-implant anchorage was investigated. RESULTS: Only the age showed a statistically significant negative correlation with MARPE success and all the skeletal measures. There was an 83.3% success rate among individuals aged 15 to 19 years, 81.8% from 20 to 29 years, and 20% from 30 to 37 years. MPS maturation showed a negative correlation with the expansion effect. Subjects with stages B or C of MPS maturation showed a 100% success rate, followed by stage D (62.5%) and stage E (58.3%). CONCLUSIONS: As age increased, there was a decrease in MARPE success and the skeletal effects of maxillary expansion. Sex and bicortical mini-implant anchorage were not shown to be relevant factors. There was no correlation between MPS maturation and MARPE success; however, it was observed that all cases of MARPE failure were classified as stage D or E of MPS maturation.

Uma nova estratégia para PDT antimicrobiana em Endodontia / A new approach for antimicrobial Endodontic PDT

O presente estudo avaliou diferentes parâmetros como concentração do fotossensibilizador,tempo/energia de irradiação e uso de fibras ópticas, na a PDT para redução bacteriana intracanal.Avaliou-se, in vitro, em cubetas de quartzo contendo concentrações de 50, 100, 150 e 300μM de solução aquosa de Azul de Metileno (AM) a produção de espécies reativas de oxigênio (EROs) em irradiações adicionais de 30s com um laser de diodo emitindo em 660nm. Utilizando-se a mesma metodologia, foi avaliado os efeitos na produção de EROs com e sem o uso de fibra óptica. Concentrações de 50, 150 e 300μM de AM e análise por imagens, avaliaram a formação do fenômeno escudo óptico. Dez incisivos contaminados com P. Aeruginosas bioluminescentes, foram utilizados para analisar as energias/tempo para redução bacteriana intracanal. Imagens obtidas nos dentes avaliaram a contaminação inicial. Os canais foram preenchidos com o fotossensibilizador (PS) eirradiações de 2,4J foram realizadas. A cada irradiação, imagens foram obtidas e a redução bacteriana avaliada. A formação de EROs é maior em concentrações menores do PS, assim como a formação de escudo óptico. O uso de fibra aumenta a formação de ERO quando comparado a irradiação sem fibra. Irradiação com 7J impossibilitou a detecção de biofilme intracanal. A concentração do PS em que há maior eficiência na formação de EROs e menor formação de escudo óptico se encontra entre 50 a 100μM. O uso de fibras ópticas contribui para maior formação de EROs. Energia de irradiação mínima de 7J promove significativa redução bacteriana intracanal.

This study evaluates different approach such as photos sensitizer (PS) concentration, irradiation time/energy, and the use of optical fiber for intracanal microbial reduction. In a quartzcurvet, aqueous solution of Methylene blue at 50, 100, 150 and 300μM was tested for reactive oxygen species production (ROS) after successive irradiations of 30s with a diode laser (660nm,100mW). Using the same methodology, the ROS production was tested using an optical fiber. Image analyses evaluated the presence of optical shield in 3 different concentration of PS. Tencentral incisors were contaminated with bioluminescent P. aeruginosas to test the ideal energy/time for endodontic microbial reduction. Initial contamination was recorded by image after biofilm grown. The root canals were ful filled with Ps and irradiated with successive energiesof 2.4J. After every irradiation new images were recorded to compare the microbial reduction. ROS formation was improved using low concentration of PS, such as optical shield formation. The use of optical fiber did enhance the ROS formation when compared to irradiation with thelaser tip. Energy of 7J was the minimal energy to achieve lost of bioluminescent signal. For more efficient ROS production and minor optical shield presence, a concentration between 50 and 100μM seams to be ideal. The use of an optical fiber improves ROS production. Energy of 7J promotes significative intracanal de contamination.