Resin Composite Surface Pre-Reacted Glass-Ionomer (S-PRG) Filler for Non-Carious Cervical Lesions: A Double-Blinded, Randomized, Split-Mouth Clinical Trial

<b>Background/Objectives</b>: This double-blinded study aimed to evaluate the clinical performance of a giomer restorative material in comparison to a nanotechnology-based restorative system for the restoration of non-carious cervical lesions over a period of 48 months. <b>Methods</b>: A 48-month randomized, controlled, split-mouth trial was conducted with 49 subjects at its baseline, which was reduced to 34 subjects at follow-up, yielding a statistical power of 69.55%. Cervical lesions were restored using either BEAUTIFIL II LS (BL) or 3M/ESPE Filtek Supreme Universal Restorative (FS). Clinical assessments were performed by blinded examiners, excluding the one who placed the restorations. Evaluations were based on the Hickel criteria, covering esthetic, functional, and biological properties, with comparisons made using the Wilcoxon signed-rank test. <b>Results</b>: Hickel scores were analyzed with the Mann-Whitney U test to compare BL and FS groups within subjects. Changes in median Hickel scores, sensitivity, and the gingival index were assessed via Friedman's test, followed by Wilcoxon signed-rank tests with a Bonferroni correction for post-hoc comparisons. The p-values under 0.05 were considered significant, except with the Bonferroni correction. Statistical analysis showed no significant differences between materials across most Hickel parameters (<i>p</i> > 0.05), though BL exhibited a trend of better surface staining (76.5% excellent with BL vs. 76.5% excellent with FS) and adjacent mucosa, while FS showed slight advantages in surface luster and color match. <b>Conclusions</b>: The clinical evaluation of restorations for non-carious cervical lesions using giomer and nanotechnology-based restorative systems revealed no statistically significant differences according to the Hickel criteria, indicating a similar clinical performance for both restorative materials.