Resumo

ANDRADE, Débora Cintra; TOLEDO, Bruno Alves de Souza  e  FABIO, PICOLI. Reduction in the degree of curvature of the mesial canals of lower molars after coronal flaring with stainless steel or niti rotary instruments. RGO, Rev. gaúch. odontol. (Online) [online]. 2013, vol.61, n.2, pp. 187-192. ISSN 1981-8637.

Objective This study assessed different flaring methods for eliminating coronal interferences in root canals of lower motors by analyzing the reduction in the degree of canal curvature after instrumentation. Methods Forty mesial roots of lower molars were used. The mesiobuccal and mesiolingual canals were irrigated with an aqueous solution of 1% NaOCl and explored throughout. Standardized radiographs were taken with K files #10 inside the canals for assessment of the original degree of curvature before the following instrumentation: Group I - Hedströen files and Gates-Glidden burs; Group II - LA Axxess burs; Group III - rotary nickel-titanium (NiTi) K3 files; Group IV - CP-Drill burs. The roots were radiographed again with K #10 files inside after the instrumentation for assessment of the new degrees of curvature. The mean degrees of curvature of the mesiobuccal and mesiolingual canals before and after instrumentation were calculated. Reduction in the degree of canal curvature was given by the difference between the degrees before and after instrumentation. Results Statistical analyses showed that all study method were capable of reducing the degree of curvature of the root canals by removing coronal interferences. Conclusion The LA Axxess burs were the most efficient study instruments for removing the anatomic coronal interferences, reducing the degree of curvature of the mesial canals by a mean of 11.52º.

Palavras-chave : Dental instruments.; Endodontics.; Root canal preparation..