Effect of thermocycling on the microleakage of conventional and resin-modified glass ionomers.

PURPOSE

To compare the effect of thermocycling on the microleakage of conventional and resin modified glass ionomer restorative materials.

MATERIALS AND METHODS

Class V preparations, centered on the CEJ, were prepared on the lingual and facial surfaces of 30 extracted human third molar teeth. Preparations were conditioned and restored randomly on one surface with Ketac-Fil and on the other surface with Photac-Fil. Restorations were protected during curing, finishing, and storage with Ketac-Glaze. Specimens were aged in room temperature distilled water for 7 days. Half of the specimens were thermocycled for 2,500 cycles in 5 degrees-55 degrees water baths with 5-second dwell times. All specimen apices were sealed with red compound, occlusal fissures sealed with pit/fissure sealant, and surfaces painted to within 1.5 mm of restoration margins with red nail polish. Specimens were stained with 5% methylene blue, invested in orthodontic resin, and sectioned faciolingually. The percentage of dye penetration along the tooth restoration interface was measured with a digital imaging system.

RESULTS

Statistical analysis showed that neither thermocycling or type of material had a significant effect on dye penetration (P > 0.5).