Resumo

SALLES, Alexandre Azevedo et al. Temperature rise on the root surface during cervical preparation using LA Axxess bur - an in vitro study. RSBO (Online) [online]. 2010, vol.7, n.2, pp. 193-199. ISSN 1984-5685.

INTRODUCTION AND OBJECTIVE: There is very little information on the scientific literature regarding the temperature rise on the outer root surface during cervical preparation using LA Axxess burs. The aim of this in vitro study was to investigate the effect, regarding the temperature variation, of the diameter of the LA Axxess bur and the type of movement applied during cervical preparation of mesiobuccal (MB) and mesiolingual (ML) root canals of extracted mandibular human molars. MATERIAL AND METHODS: 30 extracted mandibular human molars were randomly divided into three experimental groups according to the diameter of the bur to be used: 20/.06, 35/.06 and 45./06. A single operator applied the following movements on the samples during cervical preparation: 1) continuous movement in the MB root canal; 2) intermittent movement in the ML root canal. Each movement lasted 5 seconds. Temperature variation was measured by a thermocouple fixed on the root and connected to a digital thermometer. Variation temperature data was analyzed through ANOVA test with significance level of 5% in relation to the independent variables: diameter of the bur and type of movement. RESULTS: The diameter of the bur did not influence on the temperature rise. The continuous movement showed a higher significant rise on the outer root temperature than the intermittent movement. CONCLUSION: The use of LA Axxess burs on cervical preparation during 5 seconds is safe in relation to the temperature rise regardless the diameter of the bur and the type of movement applied.

Palavras-chave : root canal; cervical preparation; type of instrument.