Surface roughness and enamel loss with two microabrasion techniques.

Aim: The aim of this study was to evaluate and compare the surface roughness and enamel loss produced by two microabrasion techniques.

Methods And Materials: Bovine teeth were selected and an area was delimited for microabrasion techniques. Surface roughness was determined before and after treatment using a digital profilometer. Specimens were randomized to one of two acid treatments (n = 10): 18% hydrochloric acid (HCl) and pumice or 37% phosphoric acid (H3PO4) and pumice. Acid treatments were applied using a wooden spatula for 5 seconds for a total of ten applications. Then, specimens were sectioned through the center of the demineralization area to obtain 80 microm thick slices. The wear produced by the microabrasion techniques was evaluated using stereomicroscopy (40 x). The greatest depth (microm) and the total surface area (microm(2)) of demineralization were measured using the Image Tool software (University of Texas Health Science, San Antonio, TX, USA). In addition, three specimens of each group were subjected to SEM analysis at different magnifications.

Results: The mean surface roughness was statistically lower for HCl than for H3PO4 (p < 0.001). Deeper demineralization (p < 0.003) and a larger total demineralization area was observed for HCl (p < 0.005). Under SEM analysis H3PO4 showed a selective conditioning etching, while HCl exhibited a non-selective pattern.

Conclusions: Microabrasion using H3PO4 produced greater surface roughness but less demineralization than the microabrasion technique using HCl.

Clinical Significance: Both microabrasion techniques effectively remove the superficial enamel layer. However, the technique using H3PO4 was less aggressive, safer, and easier to perform.