EVALUATION OF MICROTENSILE BOND STRENGTH AT THE COMPOSITE-DENTINE INTERFACE WITH MODIFIED PHOSPHORIC ACID ETCHANTS –AN IN-VITRO STUDY
Aim of the study: To evaluate the micro tensile bond strength at the dentin – resin interface after using different etchants. Materials and methods: Twenty four extracted caries free molars are collected, cleaned of debris and stored in a hypotonic solution. Occlusal surfaces of the teeth were flattened, which eliminates the pits and grooves, thereby the surface of the Enamel was standardized.Teeth will be randomly divided into four groups of 6 teeth each depending on the etchant used.Group I : 37% phosphoric acid (Control),Group II : 37% phosphoric acid+2% chlorexidine digulconate, Group III: 37% phosphoric acid+2% EDTA, Group IV: 37% phosphoric acid+20% tannic acid. To test the microtensile bondstrength test specimens should be sectioned through centre of the restoration (both buccoingually and mesiodistally).
Results: Stable micro tensile bond strength values were observed only for the modified phosphoric acids (CHX,EDTA,TA).
Conclusion: Compared to the control, the phosphoric acid etchants which contained protease inhibitors (CHX,EDTA,TA) promoted the stability of composite-dentin microtensile bond strength.
Clinical significance: Providing an effective way to prolong the stability of the composite-dentin bonds without an additional bonding step.
Keywords: Chlorexidine, EDTA, Micro-tensile bond strength, Phosphoric acid, Tannic acid