48-Month Clinical Performance of a Glass-Hybrid in Extended-Size Class-II Cavities

Objectives: To evaluate the clinical performance of a glass hybrid restorative compared to a resin composite in the restoration of large and deep Class II cavities after 48 months
Methods: A total of 108 extended size (the proximal box in occlusion and width of the proximal box not interfering with the peak of the cusps) Class II lesions in 37 patients were either restored with a glass hybrid restorative or with a micro-hybrid composite resin in combination with selective etching by two experienced operators according to the manufacturer’s instructions. Two independent examiners evaluated the restorations at baseline and at 12-, 24- 36- and 48-month recalls according to the modified USPHS Criteria. Negative replicas at each recall were examined under SEM to evaluate surface characteristics. The Cochran Q-test was used to compare the changes across different time points within each restorative material. The changes in each category within the restorative groups were compared using the Fisher Exact test (α=0.05).
Results: After 48 months, 90 restorations were evaluated in 32 patients (recall rate: 86.5%). Five glass hybrid restorations were missing; 4 were due to bulk fractures (3 were at 12 months, 1was at 48 months) and 1 was due to proximal fracture at 24 months. Six glass hybrid restorations exhibited color differences starting from baseline (p<0.05). Both restorative materials showed increased bravo scores in terms of anatomic form, marginal adaptation and polishability compared to baseline. Secondary caries was not seen in any groups. No significant differences were observed between the two restorative materials for the other criteria evaluated (p>0.05). SEM observations exhibited acceptable surface and marginal adaptation characteristics for both restorative materials.
Conclusions: Although glass hybrid restorations showed mismatch in color, these materials could be considered as permanent restorative materials for the restoration of large Class II cavities after 48 months.