Microphotographic Assessment of Enamel Surface using Self-Etching Primer and Conventional Phosphoric Acid: An In vitro Study.

Introduction: Conventional acid-etching method irreversibly removes several microns of enamel surface and also involves many steps. Hence, a simplified technique that minimizes enamel loss, improves adhesion procedures, prevents saliva contamination, and saves chair time, thereby producing clinically useful bond strength, would be valuable.

Aim: To assess and compare the bonding mechanism of a self-etching primer (SEP) to that of phosphoric acid on enamel of the human permanent teeth by a scanning electron microscope (SEM).

Materials and Methods: Thirty freshly extracted premolars were randomly divided into two groups of fifteen teeth each - the control group I (phosphoric acid) and experimental group II (self-etching primer). Brackets were bonded using Transbond XT adhesive on the buccal surfaces of the teeth after etching and priming according to their respective protocols. The teeth were then sectioned and the samples were subjected to a protocol of demineralization cycles. After complete dissolution of dental tissues, the specimens were gold sputter coated and evaluated under SEM.

Results: A characteristically uniform etch pattern was seen in the resin samples of the phosphoric acid/Transbond XT primer group, which revealed increased roughness and resin tags penetrating the demineralized enamel surface, whereas with Transbond Plus SEP, a regular resin tag distribution was observed which showed less magnitude when compared with the control group.

Conclusion: From the study, it was concluded that Transbond Plus SEP produced an etch pattern which was more conservative than conventional phosphoric acid system.