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

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.