Evaluation of the riboflavin photo-oxidation as an exogenous agent for cross-linking induction on collagen dentin.

• Grant number: 11/16181-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2011
• End date: February 28, 2013
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Paulo Francisco Cesar
• Grantee: Jaqueline Aguiar Tartaroti
• Host Institution: Faculdade de Odontologia (FO). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

AbstractBiomodification of existing hard tissue structures, especially tooth dentin, is an innovative approach proposed to improve the biomechanical and biochemical properties of tissues for potential preventive or reparative/regenerative therapies. The objectives of the study were to systematically characterize dentin matrices biomodified by riboflavin followed by ultraviolet-A (UVA) exposure. The adhesive interface will also be analyzed in terms of bond strenght. Methods: Sound human molars will be sliced into 0.5 mm-thick dentin slabs that will then be demineralized and treated with one of the four groups, as follows: control (distilled water), 0.1% riboflavin (2 mmol/L), UVA (»=370 nm at 3 mW/cm2 for 2 min), 0.1% riboflavin + UVA. The modulus of elasticity of the demineralized dentin will be assessed by means of a three-point bending test at baseline and after different treatments. Samples will be stored in artificial saliva and re-tested after 6 and 12 months. The effect of riboflavin/UVA on the resin-dentin bond strength will be accessed after the application of two commercial available adhesive systems: One-Step Plus (OS) or Adper Single-Bond Plus (SB). After 24 hours, specimens will be sectioned into 0.8 x 0.8 mm beams and either tested immediately or stored in artificial saliva for 6 or 12 months prior to micro-tensile testing (µTBS). Data will be statistically analyzed.