Effect of metalloproteinases inhibitors and volatilization temperature on the bond strength, nanoleakage, and collagenolytic activity of adhesive restorations

• Grant number: 18/08219-5
• Support Opportunities: Regular Research Grants
• Start date: December 01, 2018
• End date: November 30, 2020
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Anderson Catelan
• Grantee: Anderson Catelan
• Host Institution: Faculdade de Ciências da Saúde (FCSA). Universidade do Oeste Paulista (UNOESTE). Presidente Prudente , SP, Brazil

Abstract

Even with the evolution of dental materials and techniques, adhesive restorations failure in long term. The aim in this study will be to evaluate the effect of dentin pretreatment with metalloproteinase inhibitors (chlorhexidine - CHX and glutaraldehyde - GD) and volatilization temperature (23 and 40ºC) on the bond strength (BS), nanoleakage (NL), and collagenolytic activity (CA) of adhesive restorations after 24 h and aging. Thirty-six healthy human molar years collected (CAAE 73605617.4.0000.5515), the teeth will have coronary dentin of medium depth exposed, and then the acid conditioning will be performed, followed by the treatment of dentin with deionized water (control), CHX 2%, or GD 5%. At the end, the adhesive system will be applied according to manufacturer's recommendation, volatilized at 23 or 40ºC, and light cured to posterior confection of a composite resin block. The specimens will be cut into 0.8 x 0.8 mm sticks, with half of the beams will be tested after 24 h or aging (10,000 thermal cycles and 4 weeks of storage in 0.2% collagenase). The BS (n = 6) will be subjected to a microtensile test using a universal test machine and NL will be analyzed by scanning electron microscopy after infiltration with silver nitrate (n = 6). The CA (n = 6) will be assessed by in situ zymography using a laser scanning confocal fluorescence microscope. The obtained data will be analyzed with the most appropriate statistical tests with the level of significance of 5%. Pretreatment of dentin with protease inhibitors combined with use of warming air for more effective solvent evaporation of adhesive systems promotes higher bond strength, lower nanoleakage and collagenolytic activity in adhesive restorations. (AU)