This study compared the marginal gaps of CAD/CAM lithium disilicate (LDS) crowns constructed using a contemporary and older scanner/milling unit combination at three different cement spaces.
Methods
Twenty-four undergraduate students prepared a Columbia model lower left first molar for an LDS crown in a simulated environment. From each crown preparation, one LDS crown was constructed using an E4D scanner/E4D milling unit (E4DS/E4DM) and TRIOS 3 scanner/Sirona inLab MC X5 milling unit (TRIO/MCX5) at cement space settings of 50, 100 and 200 μm. Each LDS crown was positioned onto the original crown preparation, and then a stereomicroscope was used to make three vertical marginal gap measurements at four locations (mid-buccal, mid-lingual, mid-mesial and mid-distal). The mean marginal gap (MMG) was calculated for each crown and each individual tooth surface.
Results
The MMGs of CAD/CAM LDS crowns constructed by TRIO/MCX5 were 72.31 at 50, 63.73 at 100 μm and 46.23 μm at 200 μm, which were smaller than E4DS/E4DM at each cement space.
期刊介绍:
The Australian Dental Journal provides a forum for the exchange of information about new and significant research in dentistry, promoting the discipline of dentistry in Australia and throughout the world. It comprises peer-reviewed research articles as its core material, supplemented by reviews, theoretical articles, special features and commentaries.