Marginal adaptation and shear bond strength of composite restorations under erosive cycling conditions

• Grant number: 15/08383-1
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date until: August 10, 2015
• End date until: February 09, 2016
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Alessandra Buhler Borges
• Grantee: Rayssa Ferreira Zanatta
• Supervisor: Annette Wiegand
• Host Institution: Instituto de Ciência e Tecnologia (ICT). Universidade Estadual Paulista (UNESP). Campus de São José dos Campos. São José dos Campos , SP, Brazil
• Institution abroad: Göttingen University, Germany
• Associated to the scholarship: 13/12069-5 - Influence of surfactant agents on acquired pellicle protector effect during dental erosion development, BP.DR

Abstract

When erosive tooth substance loss reaches a certain degree, restorative rehabilitation of the affected teeth becomes necessary. As a result of the improvements in composite and adhesive materials, the rehabilitation of eroded dental hard tissues in a less invasive manner becomes possible. However, as the longevity of restorations depends not only on the durability of the material per se, but also on the patient-related factors, it is quite likely that restorations are extensively stressed in patients suffering from dental erosion. So far, only few studies analysed the behaviour of various dental materials under acidic and erosive lesions. The durability of the adhesive interface under erosive conditions was not analysed so far. The aim of this study is to analyse the marginal adaptation and shear bond strength of composite restorations under erosive cycling conditions. The study will be divided in two parts. The first experiment will use 60 sound human premolars or molars, in which class V cavities will be prepared in the buccal face and restored with an etch&rinse adhesive (n = 30) or a self-etch adhesive (n = 30) and a composite. The specimens will be either aged by conventional thermocycling (10000 cycles, 5-55° C, approximately 6 days, each n = 10) or by thermocycling including storage in hydrochloric acid (pH 2.1, 6 times/day (each 5 min), each n = 10). The remaining specimens (each n = 10) are not aged, but immediately further processed. Then, all specimens will be immersed in silver-nitrate for 24 h followed by photo-developing solution for 8 h. Marginal adaptation of enamel and dentin margins will be measured by scanning electron microscope (SEM), light-microscopy and micro-computer tomography (SkyScan 1272). In the second experiment, enamel and dentin specimens (each n= 60) will be gained from bovine crowns and polished flat. The specimens will be conditioned with the etch&rinse adhesive or the self-etch adhesive (each n = 30), and the composite will be adhered to the surface. Specimens will be treated by conventional thermocycling, by thermocycling including storage in hydrochloric acid or remain un-aged in the same way as in the first experiment. Shear bond strength is tested in an universal testing machine and failure modes will be assessed. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

ZANATTA, R. F.; LUNGOVA, M.; BORGES, A. B.; TORRES, C. R. G.; SYDOW, H-G; WIEGAND, A.. Microleakage and Shear Bond Strength of Composite Restorations Under Cycling Conditions. Operative Dentistry, v. 42, n. 2, p. E71-E80, MAR-APR 2017. (15/08383-1)