Murilo Priori Alcalde1, Marco Antonio Hungaro Duarte1, Clovis Monteiro Bramante1, Bruno Carvalho de Vasconselos2, Mario Tanomaru-Filho3, Juliane Maria Guerreiro-Tanomaru3, Jader Camilo Pinto3, Marcus Vinicius Reis Só4, Rodrigo Ricci Vivan5. 1. Department of Restorative Dentistry, Dental Materials and Endodontics, Bauru Dental School, University of São Paulo, Dr Otávio Pinheiro Brisolla 9-75, Bauru, São Paulo, 17012-901, Brazil. 2. Department of Endodontics, Federal University of Ceará, Campus Sobral. Cel. Stanislau Frota St, Sobral, Ceará, Brazil. 3. Department of Restorative Dentistry, Araraquara Dental School, São Paulo State University, R. Humaitá, 1680, Araraquara, São Paulo, Brazil. 4. Department of Restorative Dentistry, Federal University of Rio Grande do Sul, Paulo Gama Av., 110, Porto Alegre, Rio Grande do Sul, Brazil. 5. Department of Restorative Dentistry, Dental Materials and Endodontics, Bauru Dental School, University of São Paulo, Dr Otávio Pinheiro Brisolla 9-75, Bauru, São Paulo, 17012-901, Brazil. rodrigo.vivan@fob.usp.br.
Abstract
OBJECTIVES: The aim of this study was to evaluate the cyclic and torsional fatigue resistance of the reciprocating single-file systems Reciproc Blue 25.08 (VDW GmbH, Munich, Germany), Prodesign R 25.06 (Easy Dental Equipment, Belo Horizonte, Brazil), and WaveOne Gold 25.07 (Dentsply/Tulsa Dental Specialties, Tulsa, OK, USA). MATERIALS AND METHODS: Sixty reciprocating instruments of the systems Reciproc Blue R25 (RB #25 .08 taper), Prodesign R (PDR #25 .06 taper), and WaveOne Gold (WOG #25 .07 taper) (n = 20) were used. Cyclic fatigue resistance testing was performed by measuring the time to failure in an artificial stainless steel canal with a 60° angle of curvature and a 5-mm radius located 5 mm from the tip (n = 10). The torsional test (ISO 3630-1) evaluated the torque and angle of rotation at failure of new instruments (n = 10) in the portion 3 mm from the tip. The fractured surface of each fragment was also observed using scanning electron microscopy (SEM). In addition, a supplementary examination was performed to measure the cross-sectional area of each instrument 3 and 5 mm from the tip. The data were analyzed using one-way ANOVA and Tukey's test, and the level of significance was set at 5%. RESULTS: The cyclic fatigue resistance values of PDR 25.06 were significantly higher (P < 0.05). RB 25.08 showed higher fatigue resistance than WOG 25.07 (P < 0.05). The torsional test showed that PDR 25.06 had lower torsional strength (P < 0.05). No differences were observed between RB 25.08 and WOG 25.07 (P > 0.05). PDR 25.06 showed higher angular rotation values than RB 25.08 and WOG 25.07 (P < 0.05). RB 25.08 presented higher angular rotation than WOG 25.07 (P < 0.05). The cross-sectional area analysis showed that PDR 25.06 presented the smallest cross-sectional areas at 3 and 5 mm from the tip (P < 0.05). CONCLUSION: PDR 25.06 presented the highest cyclic fatigue resistance and angular rotation until fracture compared to RB 25.08 and WOG 25.07. In addition, RB 25.08 and WOG 25.07 had higher torsional strength than PDR 25.06. CLINICAL RELEVANCE: In endodontic practice, thermally treated reciprocating instruments have been used for the root canal preparation of curved and constricted canals; therefore, these instruments should present high flexibility and suitable torsional strength to minimize the risk of instrument fracture.
OBJECTIVES: The aim of this study was to evaluate the cyclic and torsional fatigue resistance of the reciprocating single-file systems Reciproc Blue 25.08 (VDW GmbH, Munich, Germany), Prodesign R 25.06 (Easy Dental Equipment, Belo Horizonte, Brazil), and WaveOne Gold 25.07 (Dentsply/Tulsa Dental Specialties, Tulsa, OK, USA). MATERIALS AND METHODS: Sixty reciprocating instruments of the systems Reciproc Blue R25 (RB #25 .08 taper), Prodesign R (PDR #25 .06 taper), and WaveOne Gold (WOG #25 .07 taper) (n = 20) were used. Cyclic fatigue resistance testing was performed by measuring the time to failure in an artificial stainless steel canal with a 60° angle of curvature and a 5-mm radius located 5 mm from the tip (n = 10). The torsional test (ISO 3630-1) evaluated the torque and angle of rotation at failure of new instruments (n = 10) in the portion 3 mm from the tip. The fractured surface of each fragment was also observed using scanning electron microscopy (SEM). In addition, a supplementary examination was performed to measure the cross-sectional area of each instrument 3 and 5 mm from the tip. The data were analyzed using one-way ANOVA and Tukey's test, and the level of significance was set at 5%. RESULTS: The cyclic fatigue resistance values of PDR 25.06 were significantly higher (P < 0.05). RB 25.08 showed higher fatigue resistance than WOG 25.07 (P < 0.05). The torsional test showed that PDR 25.06 had lower torsional strength (P < 0.05). No differences were observed between RB 25.08 and WOG 25.07 (P > 0.05). PDR 25.06 showed higher angular rotation values than RB 25.08 and WOG 25.07 (P < 0.05). RB 25.08 presented higher angular rotation than WOG 25.07 (P < 0.05). The cross-sectional area analysis showed that PDR 25.06 presented the smallest cross-sectional areas at 3 and 5 mm from the tip (P < 0.05). CONCLUSION: PDR 25.06 presented the highest cyclic fatigue resistance and angular rotation until fracture compared to RB 25.08 and WOG 25.07. In addition, RB 25.08 and WOG 25.07 had higher torsional strength than PDR 25.06. CLINICAL RELEVANCE: In endodontic practice, thermally treated reciprocating instruments have been used for the root canal preparation of curved and constricted canals; therefore, these instruments should present high flexibility and suitable torsional strength to minimize the risk of instrument fracture.
Entities:
Keywords:
Cyclic fatigue; NiTi alloy; Reciprocating motion; Thermal treatment
Authors: Maria Guiomar Azevedo Bahia; Marta C C Melo; Vicente Tadeu Lopes Buono Journal: Oral Surg Oral Med Oral Pathol Oral Radiol Endod Date: 2005-09-30
Authors: Rafaela Andrade de Vasconcelos; Sarah Murphy; Claudio Antonio Talge Carvalho; Rajiv G Govindjee; Sanjay Govindjee; Ove A Peters Journal: J Endod Date: 2016-03-15 Impact factor: 4.171