Method: Twenty-one patients (seven for each of the three clinics) who visited for a single repair of their premolars or canines were selected. Two kinds of restorations were fabricated, a MCC using traditional method and a LDC utilizing CAD/CAM system(CEREC ACR system) per one patients’ abutment teeth. Two silicone replicas were produced per prosthetic restoration, each of which was sectioned in the center of buccolingual and mesiodistal direction to measure the marginal and internal gap. Measurement was carried out by using measuring microscope(AXIOR) and I-solutionR. Statistical analysis was performed using an independent t-test.
Result: In the comparison of the differences among each center, no significant difference in gap width was found in the lithium disilicate crown (P>.05) and the metal ceramic crown (P>.05). Significant differences in the MCC group and the LDC group were showed at reference points of buccolingual direction (P<.001) and reference points of mesiodistal direction (P<.001). As for the marginal gap, no significant difference was noted (P>.05). The internal gap was significantly bigger in the lithium disilicate crown’s axial and occlusal surfaces (P<.001).
Conclusion: The difference in internal gap was statistically significant with the lithium disilicate crown generally showing a higher value (P<.001). The difference in marginal gap was not statistically significant (P>.05) and both groups showed fitness levels that can be clinically accepted.