OBJECTIVE: The aim of this study was to evaluate the microleakage, margin gap, and microtensile bond strength of lithium disilicate under different dentin conditions using four
different resin-based cements.
MATERIALS AND METHODS: Forty-four extracted posterior teeth were prepared to receive lithium disilicate crowns to evaluate microleakage and margin gap. Four cements (Variolink Esthetic, Multilink Automix, Panavia SA, and GC FujiCEM 2) were assigned to different dentin conditions (control, immediate dentin sealing [IDS], and delayed dentin sealing [DDS]). The control group received a final restoration immediately, while IDS received OptiBond FL bonding agent then was temporized, and DDS were temporized without any additions. IDS and DDS groups were temporized and stored for two weeks in 37 °C to simulate clinical scenarios. All groups were then embedded in 50% ammoniacal silver nitrate for 24 h, then exposed to constant white LED light in a photo-developer solution for 8 h. All teeth were sectioned and evaluated using SEM.
For microtensile bond strength, thirty extracted posterior teeth and the same cements and dentin conditions were used. Dentin and e.max CAD blocks were sectioned into 1x1x6 mm2 beams and cemented according to their respective groups. After storage at 37 °C for 24 h, microtensile bond strength was analyzed, and failure mode was evaluated by SEM.
RESULTS: Analysis by one-way ANOVA and Tukey test revealed that the microleakage in the control groups was significantly lower than in the DDS group, except for Panavia SA (SAM). IDS groups were significantly lower than DDS groups except for Variolink Esthetic and Panavia SA (SAM). The margin gap for the different dentin conditions was not significant for each cement except IDS Variolink Esthetic group. Microtensile bond strength of the control and IDS groups was significantly higher than DDS groups except for Variolink Esthetic and Panavia SA with Clearfil Universal Bond Quick.
CONCLUSION: Margin gap has no effect on microleakage. Control groups showed the lowest leakage and the highest microtensile bond strength except for the Panavia SA (SAM) IDS group. IDS produced bond strength as high as that observed in the control groups for all cement types but could not prevent microleakage as efficiently as in the control group with cement containing 10-MDP monomer.
| Identifer | oai:union.ndltd.org:bu.edu/oai:open.bu.edu:2144/42685 |
| Date | 13 June 2021 |
| Creators | AlGhamdi, Abdulrahman Abdullatif |
| Contributors | Giordano, Russell, Fan, Yuwei |
| Source Sets | Boston University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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