A 12-Month Clinical Comparison of Occlusal Wear in Alloy-Reinforced Glass-Ionomer Cement and Dispersed-Phase Dental Amalgam Restorations

The clinical performance of restorative materials in posterior teeth is influenced by their mechanical properties, placement technique, cavity characteristics, and exposure to occlusal loading. Alloy-reinforced glass-ionomer cement (GIC) was developed to improve the mechanical performance of conventional GIC, although its resistance to occlusal wear requires clinical evaluation. This study was conducted to compare the occlusal wear of alloy-reinforced glass-ionomer cement (Hi-Dense) with dispersed-phase dental amalgam (Dispersalloy) over a 12-month clinical observation period. This clinical comparative study included 35 patients aged 11–37 years. Seventy Class I restorations were placed, with one Hi-Dense restoration and one Dispersalloy amalgam restoration in each patient. Occlusal wear was assessed indirectly using polyvinyl siloxane impressions and dental stone replicas. Measurements were performed at baseline, six months, and 12 months using the Ivoclar-Vivadent reference system. Two calibrated examiners independently assessed buccal wear, lingual wear, and the greatest area of wear. Descriptive means, standard deviations, absolute differences, and percentage changes were calculated from the reported measurements. The overall descriptive mean wear of amalgam was 23.17 µm at six months and 32.50 µm at 12 months. Corresponding values for Hi-Dense GIC were 138.00 µm and 224.50 µm. The difference between materials increased from 114.83 µm at six months to 192.00 µm at 12 months. Mean wear increased by 9.33 µm (40.3%) for amalgam and 86.50 µm (62.7%) for Hi-Dense GIC between six and 12 months. No restoration fracture or marginal failure was reported during the observation period. The measurements indicate substantially greater occlusal wear in Hi-Dense alloy-reinforced GIC than in dispersed-phase amalgam over 12 months. These findings are interpreted as descriptive results. Further clinical studies with longer follow-up and patient-level repeated measurements are required.