AN EVALUATION OF ETCH PATTERNS, PENETRATION DEPTH, AND BOND STRENGTH BETWEEN VARIOUS ETCHING TECHNIQUES

Objective: To compare etch patterns, penetration depth, and bond strength between conventional phosphoric acid etching, crystal growth technique and self-etching primer.Material and Methods: 60 freshly extracted maxillary first premolar teeth were collected for the study and the samples were divided into three groups for each etchant (20 samples per group).10samples from each group were tested for enamel penetration depth and tensile bond strength and remaining 10 samples from each group were used for assessing etch pattern using Scanning Electron Microscope.Results:Conventional 37%phosphoric acid produced sufficient bond strength with deeper enamel penetration.Self-etching primer produced clinically acceptable bond strength values but lower than phosphoric acid etching with moderate etch pattern.Etch pattern produced by both of these etchants were similar in appearance.Crystal growth technique by 20% polyacrylic acid failed to achieve clinically acceptable bond strength values.Conclusion:The self-etching primer can be used as an alternative to phosphoric acid etching.Etching with poly acrylic acid failed to achieve clinically acceptable bond strength even though it results in less penetration into the enamel.