Strength of base materials.

PURPOSE: To compare the punch resistance of VariGlass and Vitrebond. MATERIALS AND METHODS: Discs measuring 1.4 cm in diameter and 1.5 mm thick of VariGlass (VG) and Vitrebond (VT) light-activated lining materials, were prepared and submitted to punch testing in a universal testing machine at 7 minutes, 30 minutes and 24 hours after mixing. RESULTS: VG showed higher resistance to punch testing than the VT in the three periods evaluated (P< 0.01). The results were further compared to previous data obtained from three calcium hydroxide lining cements which gave much lower values than VG and VT (P< 0.01).