Clinical performance of high-viscosity glass ionomer and resin composite on minimally invasive occlusal restorations performed without rubber-dam isolation: a two-year randomised split-mouth study.

OBJECTIVE The aim of this clinical trial was to evaluate the 2-year clinical performances of high-viscosity glass ionomer and nanohybrid resin composite restorations performed without rubber dam isolation. MATERIALS AND METHODS Occlusal carious lesions on the right and left mandibular second molars of 56 patients (26 female, 30 male patients) were restored in a split-mouth design. High-viscosity glass ionomer (Hv-GIC) (Equia, GC) and nanohybrid resin composite (GrandioSO, Voco) were used as restorative materials. Clinical evaluations of the restorations were performed according to the Federation Dentaire Internationale criteria. Data were analysed using the Friedman's analysis of variance and Mann-Whitney U tests (α=0.05). RESULTS After 2 years, the success rate of Hv-GIC restorations was 96% and that of resin composite restorations was 100%. Hv-GIC showed lower marginal discoloration and greater surface wear and loss of anatomic form (p<0.05). Resin composite showed significantly better surface lustre. CONCLUSION The 2-year performance of resin composite was similar to that of Hv-GIC for the occlusal restorations of mandibular second molars, in spite of being performed without rubber-dam isolation. CLINICAL RELEVANCE Saliva contamination can be a clinically significant problem for dental restorations. High-viscosity glass ionomers are a satisfactory alternative to resin composites with the advantage of fast application in such situations. TRIAL REGISTRATION Clinical Trials Registration number-date: NCT04488380-22/07/2020, retrospectively registered.