Two-year Clinical Evaluation of G-Bond Dentine Bonding Agent

Two-year Clinical Evaluation of G-Bond in Non-carious Cervical Lesions. MJ Tyas,* MF Burrow, School of Dental Science, University of Melbourne, Australia

Introduction: The aim was to evaluate the clinical performance of G-Bond (GC Corporation, Japan) dentine bonding agent, over 2 y in unprepared non-carious cervical lesions (NCCL). Materials and Methods: Ethics Committee approval was obtained, and 47 restorations were placed (30 anteriors, 13 premolars, 4 molars) in 10 patients aged 45-75 y (mean 62 y), using Gradia resin composite (GC) and G-Bond dentine bonding agent, according to the manufacturer's instructions. Patients were recalled at 6 mo, 1 y and 2 y, and photographs taken for assessment of colour match and marginal discoloration. Results: All patients were available for recall at 6 mo and 1 y, and all restorations were present. One restoration had minor marginal discoloration at 1y. At 2y, one patient (4 restorations) failed to return, and one tooth had been extracted. All the remaining 42 restorations were present; four had slight and clinically insignificant marginal discoloration. Discussion: G-Bond is a HEMA-free, ‘mild-etch' all-in-one bonding agent, i.e., etching, priming and bonding are achieved simultaneously. The functional ionomer 4-MET and a phosphate ester achieve bonding by hybridization. The absence of HEMA precludes possible hypersensitivity. Pre-etching the uncut enamel with phosphoric acid overcomes the sub-optimal etching which occurs with ‘mild-etch' dentine bonding agents, which is confirmed by the absence of enamel marginal staining. The mild staining at the dentine margin could indicate bond degradation, but may also be a consequence of the difficulty of isolation of the area during restoration. A key requirement when using G-Bond is to dry the adhesive aggressively in order to evaporate the acetone solvent and thus prevent phase separation. Conclusion: G-Bond shows good clinical performance in NCCL after 2 y. (Supported by GC Corp, Japan.)