In vitro dentin bond strength and microleakage of nano-ionomer restorative in comparison with compomer

摘要

The aim of this study was to evaluate the microleakage and microtensile bond strength (mTBS) of annano-ionomer restorative in comparison with a compomer in primary teeth. Standardised class Vncavities were prepared at the cementoenamel junction on the buccal and lingual surfaces of 10nteeth to test microleakage of materials. Cavities were randomly distributed into one of two groupsnfor restoration with either a nano-ionomer RMGIC (Ketac N100; 3M ESPE, St Paul, MN, USA) or ancompomer (Dyract Extra; Dentsply, Konstanz, Germany). After thermocycling, specimens werenimmersed in a 0?5% aqueous solution of basic fuchsine for 24 h at 37uC. After sectioningnbuccolingually, dye penetration scores were determined under a stereomicroscope. Occlusalnsurfaces of 20 teeth were cut to expose a flat dentin surface and abraded with wet 600 grit siliconncarbide paper to evaluate mTBS of materials. Specimens were randomly distributed into twongroups and the restoratives were applied to all dentin surfaces according to manufacturer’sninstructions. Specimens were stored in distilled water at 37uC for 24 h and tested for mTBSn(1 mm min21). Failure modes were determined under a stereomicroscope. Differences innmicroleakage between groups were not statistically significant (p.0?05). Bond strength ofnKetac N100 (13?8 MPa) was found significantly lower than Dyract Extra (44?6 MPa) (p,0?05).nWhile adhesive failure (65%) was the most common failure type in Ketac N100 group, cohesivenresin (40%) and adhesive failures (40%) were generally observed in Dyract Extra. There was nonsignificant relationship between bond strength and failure type (p.0?05). Although nano-ionomernrestorative presented lower bond strength compared to compomer, no difference was observednbetween microleakage of the two materials.