Aim The aim of the present study was to evaluate the clinical performance of a glass hybrid restorative compared with a nano-ceramic composite resin in non-carious cervical lesions (NCCLs) of patients with bruxism. Materials and methods Twenty-five patients with NCCLs and bruxism were enrolled in the present study. Before treatment, the dimensions of the NCCLs (depth, cervico-incisal height, and mesio-distal width) and internal angles were measured. Degree of tooth wear (TWI) and gingival conditions were recorded. A total of 148 NCCLs were randomly restored with a glass hybrid restorative system (GH) (Equia Forte Fil, GC, Tokyo, Japan) or a nano-ceramic composite resin (RBC) (Ceram.X One Universal, Dentsply, DeTrey, Konstanz, Germany). The restorations were evaluated at baseline and after 6, 12, and 24 months according to the modified USPHS criteria. Data were analyzed with Pearson's chi-square, Fisher's exact, Mann-Whitney U, and Cochran's Q tests (P < 0.05). Results At the 24-month recall, 126 restorations in 22 patients were evaluated. The recall rate was 88.0%. No significant difference was found between the materials for retention (P = 0.285), and no relationships were found between internal angle, depth, cervico-incisal height, or mesio-distal width and retention of the restorations (P > 0.05). A significant difference was observed between the materials for marginal adaptation (P = 0.002), but no relationships were found among depth, cervico-incisal height, and mesio-distal width and marginal adaptation (P > 0.05). RBC showed better results for marginal adaptation. Between marginal adaptation, TWI, and the gingival index, correlations were significant (P < 0.001, P = 0.002). A significant change was found in marginal discoloration in GH and RBC over time (P = 0.039 and P = 0.004, respectively). Neither secondary caries nor tooth sensitivity was observed on any of the restorations at any evaluation. Conclusion Although nano-ceramic RBC showed better marginal adaptation than GH, both tested restoratives showed clinically acceptable performance for the restoration of NCCLs of patients with bruxism after 24 months of clinical service.