Microleakage of Glass-Hybrid and Glass-Ionomer Restorative Materials in Primary Dentine

Objectives: The aim of the study was to evaluate microleakage of a glass-hybrid (GH), high-viscous (HV-) and resin-modified (RM-) glass-ionomer (GI) restoratives to sound (SD) and caries-affected (CAD) primary dentine.
Methods: Occlusal cavities were prepared in 120 primary molars and randomly divided into two groups: SD and CAD. Teeth (n=12) were restored with a GH (Equia Forte HT, GC Int- EF), two HV-GI (Equia Fill, GC Int- E; Ketac Molar, 3M ESPE- KM), and two RM-GI (Fuji II LC, GC Int- II, Photac Fill, 3M ESPE- PF) materials. Samples were immersed in artificial saliva at 37°C for 7 days, and subsequently exposed to the thermal aging (10.000×). Afterwards, teeth were protected up to 1 mm to the restoration margins, immersed into methylene-blue for 24 hours, and sectioned in mesio-distal direction. Microleakage was analyzed in two sites (mesial and distal cavity wall) using an optical digital microscope (magnification 300×).
Results: Microleakage of analyzed restorative materials was: I) for SD: EF (0.29±0.35 mm) < E (0.33±0.32 mm) < II (0.42±0.43 mm) < KM (0.89±0.68 mm) < PF (1.10±0.31 mm); II) for CAD: EF (0.77±0.65 mm) < E (0.88±0.67 mm) < II (0.92±0.52 mm) < PF (1.45±0.21 mm) < KM (1.73±0.40 mm). All materials except PF showed higher microleakage in CAD than SD (p<0.05, Mann-Whitney test). No microleakage was noted in SD group for: EF (50%), II (42%), and E (33%).
Conclusions: Microleakage of GH and GI restorative materials is higher in primary CAD than SD. Novel restorative formulations are likely to provide better cavity sealing compared to the previous generations of GI materials.