One-Year Clinical Performance of Injectable and Paste-Type Composite Resins in Non-Carious Cervical Lesions Prepared with Er,Cr:YSGG Laser and Acid Etching: A Randomized Clinical Trial

Background/Objectives: Non-carious cervical lesions (NCCLs) are common defects in adults that can lead to dentin hypersensitivity and aesthetic concerns, for which composite resin restorations currently represent the gold standard of care. However, evidence regarding the long-term clinical superiority of high-filled injectable composites and Er,Cr:YSGG laser-based cavity preparation remains limited. The present study aimed to compare the 1-year clinical performance of two different surface preparation protocols (Er,Cr:YSGG laser vs. conventional bur preparation with phosphoric acid etching) and two composite resin types (high-filled injectable vs. conventional paste-type) in the restoration of NCCLs. Methods: In this prospective, split-mouth, randomized controlled clinical trial, a total of 168 NCCLs in 27 patients were restored. Lesions were randomly allocated to four groups according to the combination of surface preparation (Er,Cr:YSGG laser or phosphoric acid etching) and high-filled injectable composite (G-ænial Universal Injectable) or paste-type composite (G-ænial Anterior). The same universal adhesive system was used in all cases. Clinical evaluations were performed by a blinded examiner at 1 week, 6 months, and 12 months, using the FDI World Dental Federation criteria. Results: At the 1-year follow-up, 25 patients and 150 restorations were available for evaluation, corresponding to a recall rate of 98.22%. High clinical acceptability was observed in all groups with respect to aesthetic, functional, and biological parameters. Retention was 100% in the acid-etched paste-type composite group and ranged from 94.7% to 97.4% in the remaining groups, with no statistically significant differences among groups (p > 0.05). A transient increase in postoperative sensitivity was detected in the laser groups at the 1-week evaluation (p = 0.026); however, sensitivity scores declined to zero in all groups at 6 months and 1 year. Conclusions: High-filled injectable composites demonstrated 1-year clinical performance comparable to that of conventional paste-type composites in the restoration of NCCLs. Er,Cr: YSGG laser-based cavity conditioning produced outcomes similar to conventional phosphoric acid etching with respect to retention, marginal adaptation, and biological compatibility. The early increase in laser-related postoperative sensitivity was transient and did not compromise long-term clinical success. Taken together, the ease of application and favorable clinical performance of injectable composites indicate that these materials constitute a reliable alternative for the restoration of non-carious cervical lesions.