Abstract
BACKGROUND: Micro-abrasion enables conservative stain removal with tooth preservation, enhancing color and microhardness in line with minimally invasive dentistry principles. The aim of this in vitro study was to compare the effects of three micro-abrasion materials Antivet®, Oplasture®, and a prototype paste (37% phosphoric acid with Aluminum oxide powder) against an untreated control on the color stability and microhardness of simulated stained enamel surfaces. METHODS AND MATERIAL: A total of 120 extracted, caries-free human teeth were utilized. The teeth were randomly allocated into four groups (n = 30). Group 1 (control, no treatment), Group 2 (Antivet®: 21% hydrofluoric acid (HF)), Group 3 (Oplasture®: 6.6% hydrochloric acid (HCl) with silicon carbide), and Group 4 (prototype paste: 37% phosphoric acid with aluminum oxide powder). Specimens were stained by immersion in coffee or cola solutions at 37 °C for 8 h daily over 5 days, with interim storage in artificial saliva, and further subdivided (n = 15) by staining type. Color analysis and microhardness testing were performed at baseline, post-staining, and post-treatment. Data were analyzed using the Shapiro-Wilk test, Levene's test, one-way ANOVA, and Holm's method for multiple comparisons. RESULTS: Statistically significant differences in enamel color change (ΔE) were observed among micro-abrasion materials versus control (p < 0.001), with the prototype paste inducing the highest ΔE after staining. Only Antivet® showed solution-dependent ΔE differences (p = 0.035). Enamel microhardness decreased significantly post-staining, confirming demineralization. Oplasture® achieved the greatest microhardness recovery, while Antivet® and the prototype paste were moderately effective. The control group exhibited the highest microhardness loss, after cola exposure (p = 0.045), highlighting the protective effect of micro-abrasive treatments. CONCLUSIONS: All tested micro-abrasive materials effectively enhanced tooth color and enamel microhardness. Antivet® appears to be a viable alternative to hydrochloric acid-based products. The prototype paste emerged as a promising, cost-effective alternative for stain management.