The role of cysteine cathepsins in dentin erosion

• Grant number: 13/19657-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): January 01, 2014
• Effective date (End): December 31, 2014
• Field of knowledge: Health Sciences - Dentistry
• Principal Investigator: Marília Afonso Rabelo Buzalaf
• Grantee: Vinícius Taioqui Pelá
• Host Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil

Abstract

Dentin, demineralized organic matrix has a protective role against subsequent erosive challenges. However, this layer may be degraded by proteases such as matrix metalloproteinases (MMPs) and cysteine cathepsins (CCs). Recently, the use of matrix protease inhibitors has emerged as an important preventive tool against erosion dentin. However, the exact mechanism by where protease inhibitors can prevent dentin erosion, as well as most types of proteases involved in this process are still not completely known. Then, the objective of this project is to investigate the role of CCs, one of two major matrix proteases in dentin erosion. To do this, root human dentin specimens (4x4x2 mm) with a 2x4mm exposed window will be randomly assigned to 6 groups (n = 15 per group), which receive application of gels containing protease inhibitors (E-64, specific CCs inhibitor II, chlorhexidine), fluoride or no active ingredient (placebo gel), there was still a group with not gel treated. The gels are applied in a thin layer with the aid of a microbrush one time for 1 minute and carefully removed with a cotton swab. Following, the specimens are subjected to erosive demineralization, by immersion individually in 30 mL of Coke for 90 seconds, 4 times daily for 5 days. Between the stages of demineralization, will be stored individually in artificial saliva. The loss of mineralized and demineralized tissue will be assessed by profilometry (¼m). The data will be submitted to analysis of normality and homogeneity, for selecting the appropriate statistical test (p <0,05). (AU)