Glass hybrid versus resin-modified glass ionomer cement in class II restorations of primary molars: a 24 months randomised clinical trial

Purpose To compare the 24 month outcomes of a newer version of conventional glass ionomer cements (GIC; Equia Forte; GC Corp., Tokyo, Japan) and a standard resin-modified glass ionomer cement (RMGIC; Fuji II LC; GC Corp.) in Class II primary molar restorations and investigate reasons for failures. Methods Healthy and cooperative 4- to 9-year-old children with proximal surface caries lesions in all four primary molars of the same jaw, following clinical and/or radiographic examination, received Class II restorations with GIC or RMGIC, allocated randomly per quadrant. These were assessed semi-annually for 2 years using modified USPHS criteria. The radiographic examination was conducted annually, and assessed the presence of furcation/periapical radiolucencies, pathological root resorption and secondary caries lesion formation. Cox regression analyses were used to determine restoration survival between the two materials; Mc Nemar’s test was used to compare proportions of failure between the two restorative materials. The level of statistical significance was set at p < 0.05. Results Of the 63 children initially included in the study, 55 attended all four recalls, with a total of 120 restorations per material. There was a statistically significantly higher success rate in the RMGIC group compared to GIC (90.8% and 66.7%, respectively, p < 0.001). Most failures of GIC were attributed to partial or total loss of restoration (31.7%). Conclusion RMGIC Class II primary molar restorations had statistically significantly greater success compared to GIC restorations in the 24 month observation period.