A Comparative Study of a New Microtensile Testing Device for Dental Research
Gustavo Rivera *
Department of Operative Dentistry, School of Dentistry, Catholic University of Brasília, Brasília, D. F., Brazil
Lilian Marly de Paula
Department of Operative Dentistry, School of Dentistry, University of Brasília, Brasília, D. F., Brazil
Tien Li An
Department of Orthodontics, School of Dentistry, University of Brasília, Brasília, D. F., Brazil
Fernanda Cristina Pimentel Garcia
Department of Operative Dentistry and Dental Materials, School of Dentistry, University of Brasília, Brasília, D. F., Brazil
Paulo Márcio Yamaguti
University of Brasília, Brasília, D. F., Brazil
Andréia de Aquino Marsiglio
Department of Operative Dentistry, School of Dentistry, Catholic University of Brasília, Brasília, D. F., Brazil
Raquel Lanna Passos
Department of Operative Dentistry, School of Dentistry, Catholic University of Brasília, Brasília, D. F., Brazil
Ana Carolina Acevedo
Department of Dentistry, School of Dentistry, University of Brasília, Brasília, D. F., Brazil
José Alexander Araújo
Department of Mechanical Engineering, School of Technology, University of Brasília, Brasília, D. F., Brazil
*Author to whom correspondence should be addressed.
Abstract
Aims: This study aimed to compare the performance of a new microtensile bond strength (µTBS) testing device, called the Flextest device.
Study Design: This is an experimental randomised study in which composite resin/dentin stick-shaped specimens were submitted to a microtensile bond strength test in both Flextest device and Bencor Multi-T device.
Place and Duration of Study: University of Brasília (Brasília, Brazil). The duration of this study is 2 years.
Methodology: Fifteen human third molars were submitted to dentin surface exposure, polishing, bonding treatment, and composite blocks that were built up and sectioned to obtain composite resin/dentin stick-shaped specimens with a cross-sectional area of approximately 0.9 mm². One hundred composite resin/dentin specimens were assigned randomly to the Bencor Multi-T device (Danville Engineering, San Ramon, CA, USA) group (n = 50) and the Flextest device group (n = 50). Tensile bond testing was performed by a universal testing machine (MTS, Eden Prairie, MN, USA) at a crosshead speed of 1.0 mm/min. The intragroup and intergroup µTBS comparisons, and the ratios of the types of failure in each group were analysed by factorial analysis of variance, Fisher`s test, and the Chi square test at 5% significance.
Results: Both devices showed significant intragroup differences. However, the differences were not significant between the devices.
Conclusion: The new Flextest device and the Bencor Multi-t device had similar microtensile bond strength test results; however, a lower standard deviation was observed in the Flextest device group.
Keywords: Dentin bond strength, microtensile test, microtensile test device