Objective: To investigate the clinical efficacy of the microscopic layered resin build-up technique for treating Class III cavities in anterior teeth, and to analyze its impact on marginal adaptation and aesthetic scores of the restorations. Methods: We selected 86 patients with Class III anterior cavities treated at our hospital between April 2023 and September 2025 as the study subjects. Using a random number table, they were divided into a control group (conventional restoration technique) and an experimental group (microscopic layered resin build-up technique), with 43 patients in each group. We compared periodontal parameters, marginal adaptation of restorations, aesthetic scores, and restoration outcomes between the two groups. Results: Compared with pre-treatment levels, both groups showed statistically significant decreases in periodontal pocket depth, plaque index, and gingival index, and statistically significant increases in marginal adaptation, WES scores, and PES scores (P < 0.05). Compared with the control group, the study group showed statistically significant increases in WES scores, marginal adaptation, PES scores, and overall success rates, as well as decreases in the gingival index, periodontal pocket depth, and plaque index (P < 0.05). Conclusion: The use of Microscopic resin layered build-up technique technique for Class III anterior restorations improves marginal adaptation and aesthetic scores, enhances periodontal health, and yields significant clinical results.