Does air abrasion improve the retention of restorations in non-carious cervical lesions? An 18-month split-mouth randomized controlled trial

OBJECTIVE: To evaluate whether dentin airborne-particle abrasion (APA) with aluminum oxide affects the retention and clinical performance of composite resin restorations in non-carious cervical lesions (NCCLs). METHODS: This prospective, randomized, split-mouth, double-blind controlled trial included 63 participants and 126 restorations presenting at least two similar NCCLs. Restorations were randomized and allocated to either a control protocol using a universal adhesive in selective enamel etching mode and restored with bulk-fill composite resin, or to the same protocol preceded by APA preceded by airborne-particle abrasion with 50 μm aluminum oxide particles applied for 10 s at 5 bar pressure. All restorations were placed under rubber dam isolation using standardized procedures. Evaluations were performed at baseline, 6 months, and 18 months using FDI and modified USPHS criteria. The primary outcome was retention/fracture; secondary outcomes included marginal staining, marginal adaptation, postoperative sensitivity, and secondary caries. Survival was analyzed using Kaplan-Meier estimates and compared with log-rank tests. The primary inferential analysis used Cox proportional hazards regression with robust standard errors clustered by patient. Secondary outcomes were compared using McNemar's test (α = 0.05). RESULTS: After 18 months, six restorations were lost (Control: 1; APA: 5). Kaplan-Meier estimates showed high retention in both groups (Control: 96.7%, 95% CI: 92.4 to 100.0; APA: 90.3%, 95% CI: 83.3 to 98.0). The clustered Cox model indicated a higher, but not statistically significant, hazard of failure for the APA group (HR = 3.03; 95% CI: 0.74-12.37; p = 0.122). No significant differences were observed for marginal staining, marginal adaptation, postoperative sensitivity, or secondary caries. CONCLUSION: Under the parameters tested, dentin airborne-particle abrasion did not improve the clinical performance of composite restorations in NCCLs over 18 months. CLINICAL RELEVANCE: Air-abrasion of dentin in non-carious cervical lesions does not improve the clinical performance of composite resin restorations over 18 months, suggesting that this step may be unnecessary in routine practice.