Analyzing the Stability of White Spot Lesions Treated Using <scp>CPP</scp> ‐ <scp>ACP</scp> Coupled With Universal Adhesive Resin Against an Acidic Erosion Challenge

ABSTRACT Objective The management of white spot lesions (WSLs) remains challenging due to frequent exposure to acidic conditions in the oral environment. This in vitro study evaluated the surface properties of WSLs treated by casein phosphopeptide–amorphous calcium phosphate (CPP‐ACP) combined with a universal adhesive resin for the management of WSLs after subsequent exposure to an acidic beverage. Materials and Methods Sixty‐four extracted human molars were sectioned to obtain 128 specimens, of which 96 were artificially demineralized to create WSLs. Specimens were randomly allocated into eight groups: sound enamel (control); sound enamel exposed to an acidic beverage; demineralized enamel; demineralized enamel exposed to an acidic beverage; ICON resin–treated WSLs; ICON resin–treated WSLs exposed to an acidic beverage; CPP‐ACP followed by universal adhesive resin–treated WSLs; and CPP‐ACP followed by universal adhesive resin–treated WSLs exposed to an acidic beverage. Surface microhardness, surface roughness, and color change were evaluated. Qualitative surface morphology was assessed using scanning electron microscopy. Data were analyzed using one‐way ANOVA followed by Tukey's post hoc test ( α = 0.05). Results CPP‐ACP followed by universal adhesive resin–treated WSLs showed higher surface microhardness values than ICON resin–treated WSLs before and after acidic exposure ( p ≤ 0.05). However, CPP‐ACP followed by universal adhesive resin‐treated WSLs exhibited significantly lower surface roughness values after acidic exposure compared with ICON resin‐treated lesions ( p ≤ 0.05). Both treatments produced lower color change values than untreated WSLs. Following repeated acidic challenges, CPP‐ACP combined with a universal adhesive resin demonstrated lower Δ E values than ICON resin–treated WSLs ( p ≤ 0.05). Conclusion Within the limitations of this in vitro study, the findings suggest that the combination of CPP‐ACP with a universal adhesive resin was associated with more favorable surface‐related properties of treated WSLs under acidic challenge conditions. Clinical Significance The combined use of CPP‐ACP and a universal adhesive resin may contribute to improved surface integrity and esthetic appearance of white spot lesions under acidic challenge conditions; however, clinical validation is required before routine clinical application.