Rogério Lacerda dos Santos

Cytotoxicity of intermaxillary orthodontic elastics of different colors: an in vitro study

Objectives: Natural latex does not fall into the category of materials known to be entirely inoffensive. The purpose of this in vitro study was to test the hypothesis that there is no difference in the cytotoxicity between elastics of different colors and those from different manufacturers. Material and Methods: Different latex intraoral elastics of different colors (5/16 = 7.9 mm, mean load) were compared. The sample was divided into 7 groups of 24 elastics each: Group T (TP Orthodontics, natural latex elastics, control); Groups U1, U2, U3, U4, U5 and U6 (Uniden, natural latex elastics and colored elastics, namely, green, pink, yellow, red and purple, respectively). Cytotoxicity assays were performed by using cell culture medium containing epithelioid-type cells (Hep-2 line) derived from human laryngeal carcinoma. The cytotoxicity was evaluated by using the dye-uptake test, which was employed at two different moments (0 and 24 h). Data were compared by analysis of variance (ANOVA) and Tukeys test (p<0.05). Results: There was statistically significant difference (p<0.05) between Group T and all other groups (U1, U2, U3, U4, U5 and U6) at 0 and 24 h. No statistically significant difference (p<0.05) was found between Groups U1 and U5, U1 and U6, U2 and U3, U2 and U4, U2 and U5, U2 and U6, U3 and U4, U3 and U5, U3 and U6, U4 and U5, U4 and U6, and U5 and U6 at 0 and 24 h. Conclusions: The TP Orthodontics elastics promoted less cell lysis compared to the Uniden elastics regardless of their color.

Estudo comparativo in vitro da resistência ao cisalhamento da colagem e do índice de remanescente adesivo entre os compósitos Concise e Fill Magic

AIM: to compare the shear bond strength and adhesive remnant index (IRA) between the composites Concise and Fill Magic Orthodontic. METHODS: the sample consisted of 24 cattle permanent low incisors divided in two groups. In the first group 12 brackets were bonded with the Concise composite and in the second group 12 with the Fill Magic Orthodontic composite. The tests of the shear and the evaluation of the ARI were developed with the whole sample. RESULTS AND CONCLUSION: there were not significant statistic differences between the composites in the two evaluated items.

Immunosuppressants: implications in Orthodontics

INTRODUCTION: There are medications capable of affecting bone metabolism and the rate of tooth movement. Among these medications are the immunosuppressants, which act by repressing the action of T lymphocytes, however they can cause bone loss and consequently lead to osteoporosis. Osteoporosis is a common complication following kidney, heart, liver or lung transplantation. The immunosuppressant treatment for preventing organ rejection after transplantation, in general, includes glucocorticoids, cyclosporine, tacrolimus, and sirolimus. All these drugs can have jeopardizing effects on bone mineral homeostasis and consequently influence tooth movement. In recent years, however, the increasing use of immunosuppressants has raised questions about their effects on bone metabolism in patients undergoing orthodontic treatment. OBJECTIVE: The objective of this review study was to inform orthodontists about the influence of immunosuppressants on bone metabolism and tooth movement.

Discrepancia Dentaria de Bolton y Finalización de Ortodoncia: Consideraciones Clínicas

Las discrepancias entre el tamano mesiodistal de los dientes superiores e inferiores, asi como sus efectos sobre la oclusion han sido reportadas desde mediados del siglo XX. El objetivo de este estudio fue determinar la importancia de la aplicacion del analisis de discrepancias dentaria de Bolton con finalidad ortodontica. Fueron seleccionados casos de pacientes de raza blanca de ambos sexos, con edades comprendidas entre 12 y 25 anos. El analisis de las discrepancias dentarias fue realizado en la fase previa al tratamiento y posterior a la contencion. Como criterio basico para la inclusion en la muestra de pacientes en el pre-tratamiento deberian presentar todos los dientes permanentes (de primeros molares a primeros molares del lado opuesto, en ambos arcos). Fueron eliminados los casos que presentaron dientes con grandes destrucciones, restauraciones inadecuadas y dientes mal posicionados donde no fue posible la medicion adecuada entre los puntos de contacto. La medicion del tamano mesiodistal de los dientes se realizo con un caliper (Odin, Alemania), precision de 0,01 mm, por un solo examinador, previamente calibrado para realizar este procedimiento. Se midio el diametro mesiodistal mayor de todos los dientes. Las relaciones totales y anteriores fueron calculadas por las formulas respectivas, segun lo propuesto por Bolton (1958). Al finalizar, los casos mostraron que una discrepancia dentaria de Bolton maxilar o mandibular por exceso o falta dentaria, puede ser compensada por la alteracion en la forma del arco, dimension vestibulolingual y por la inclinacion axial de los dientes anteriores, utilizadas en conjunto o aisladamente en la arcada, sin perjuicio estetico y funcional.

Dentofacial characteristics of patients with Angle Class I and Class II malocclusions

Results: The results showed statistically significant differences for the measurements H.SN, Cx, UL-S, and IMPA between Groups I, II-1 and II-2 (p < 0.05). Measurements LL-S and MLA showed statistically significant difference between Groups I and II-1 only (p < 0.05). On the other hand, no statistically significant differences were found for measurement NLA among the 3 groups (p < 0.05).