Evaluation of the friction force generated by monocristalyne and policristalyne ceramic brackets in sliding mechanics

Roberta Ferreira PIMENTEL, Roberto Sotto Maior Fortes de OLIVEIRA, Maria das Graças Afonso Miranda CHAVES, Carlos Nelson ELIAS, Marco Abdo GRAVINA

Objective: To evaluate and compare “in vitro” the maximum friction force generated by three types of esthetic brackets, two types of polycrystalline conventional ceramic brackets (20/40 and InVu) and one type of sapphire monocrystalline bracket (Radiance) in dry and artiicial saliva wet settings. Also, to evaluate the inluence exerted by artiicial saliva on the friction forces of those brackets. Methods: Tests were performed in dry and artiicial saliva wet setting (Oral Balance) by using an EMIC DL 10000 testing machine, simulating a 2 mm slide of 0.019 x 0.025-in rectangular stainless steel wires over the pre-angulated and pre-torqued (right superior canine, Roth prescription, slot 0.022 x 0.030-in) brackets (n = 18 for each bracket). In order to compare groups in dry and wet settings, the ANOVA was used. For comparisons related to the dry versus wet setting, the student t test was used for each group. Results: The results showed that in the absence of saliva the Radiance monocrystalline brackets showed the highest friction coeicients, followed by the 20/40 and the InVu polycrystalline brackets. In tests with artiicial saliva, the Radiance and the 20/40 brackets had statistically similar friction coeicients and both were greater than that presented by the InVu brackets. The artiicial saliva did not change the maximum friction force of the Radiance brackets, but, for the others (20/40 and InVu), an increase of friction was observed in its presence. Conclusion: The InVu brackets showed, in the absence and in the presence of saliva, the lowest friction coeicient.

Keywords: Friction. Orthodontic brackets. In vitro. Biomedical and dental materials. Biomechanics.

How to cite: Pimentel RF, Oliveira RSMF, Chaves MGAM, Elias CN, Gravina MA. Evaluation of the friction force generated by mono and policristalyne ceramic brackets in sliding mechanics. Dental Press J Orthod. 2013 Jan-Feb; 18(1):121-7.

Saturday, November 23, 2024 02:04