Effect of nickel-titanium alloys on root canal preparation and on mechanical properties of rotary instruments

Autor(es)

Rodrigo Ricci VIVAN ^[1] ; Vanessa Abreu Sanches Marques COSTA ^[2] ; Leticia Citelli CONTI ^[3] ; Jussaro Alves DUQUE ^[4] ; Clovis Monteiro BRAMANTE ^[5] ; Marcus Vinicius Reis SÓ ^[6] ; Murilo Priori ALCALDE ^[7] ; Marco Antonio Hungaro DUARTE ^[8]

Afiliação do(s) autor(es)

^[1] Universidade de São Paulo. Bauru School of Dentistry. Department of Dentistry, Endodontics, and Dental Materials - Brasil

^[2] Universidade de São Paulo. Bauru School of Dentistry. Department of Dentistry, Endodontics, and Dental Materials - Brasil

^[3] Universidade de São Paulo. Bauru School of Dentistry. Department of Dentistry, Endodontics, and Dental Materials - Brasil

^[4] Universidade de São Paulo. Bauru School of Dentistry. Department of Dentistry, Endodontics, and Dental Materials - Brasil

^[5] Universidade de São Paulo. Bauru School of Dentistry. Department of Dentistry, Endodontics, and Dental Materials - Brasil

^[6] Universidade Federal do Rio Grande do Sul. Department of Endodontics - Brasil

^[7] Universidade de São Paulo. Bauru School of Dentistry. Department of Dentistry, Endodontics, and Dental Materials - Brasil

^[8] Universidade de São Paulo. Bauru School of Dentistry. Department of Dentistry, Endodontics, and Dental Materials - Brasil

• Tipo de documento: Artigo Científico
• Fonte: Brazilian Oral Research; v. 36, 2022-06-10.

Resumo

Abstract The aim of this study was to evaluate the quality of curved root canal preparation, torsional fatigue, and cyclic fatigue of rotary systems manufactured with different NiTi alloys. Ninety single-rooted canals with curvatures of 15° to 30o were scanned and divided into three groups according to the rotary system used: BT-Race (BTR) – 10.06, 35.00, 35.04; SequenceRotaryFile (SRF) – 15.04, 25.06, 35.04; and ProDesignLogic (PDL) – 25.01, 25.06, 35.05. Each system was used on three specimens. The teeth were prepared, scanned, and analyzed to assess increase in volume, transportation, and centering ability of the root canal. Torsional fatigue of glide path instruments (BTR 10.06, SRF 15.04 and PDL 25.01) and cyclic fatigue of the finishing instrument (BTR 35.04, SRF 35.04 and PDL 35.05) were obtained by analyzing completely new instruments (n = 10) and instruments after they had been used three times (n = 10). After the torsional and cyclic fatigue tests, the fractured surface of the new and used instruments were examined by scanning electron microscopy. Increase in volume, canal transportation, and centering ability showed no significant differences among the groups (p > 0.05). The torsional test showed that SRF 15.04 produced the highest torque values for both new and used instruments, followed by PDL 25.01 and BTR 10.06 (p < 0.05). PDL 25.01, both new and used, exhibited higher values of angular deflection followed by SRF 15.04 and BTR 10.06 (p < 0.05). As regards cyclic fatigue, use of PDL 35.05, both new and used, required a longer time and larger number of cycles than did SRF 35.04 and BTR 35.04 (p < 0.05). Clinical use affected the torsional fatigue of BTR; however, cyclic fatigue was not significantly affected (p < 0.05). All rotary systems were able to prepare the curved canals satisfactorily and were used safely on the three specimens. Relative to torsional fatigue, SRF 15.04 exhibited a higher torque, and PDL 25.01, higher angular deflection. BTR 10.06 was the most affected by clinical use. PDL 35.05 showed greater resistance to cyclic fatigue. (AU)

• Processo FAPESP: 16/19956-5 - Análise da qualidade do preparo e do retratamento de diferentes instrumentos associados ou não a diferentes protocolos de agitação do irrigante
• Beneficiário: Jussaro Alves Duque
• Modalidade de apoio: Bolsas no Brasil - Doutorado