A Comparison Between the Occlusal Morphology of Virtually Reconstructed Posterior Crowns and Natural Molars

This study was performed to evaluate the occlusal morphologic similarities between virtually reconstructed full crowns and original natural teeth. A total of 40 stone cast sets with untreated first molars (22 maxillary and 18 mandibular) were scanned and saved as three-dimensional virtual models. The 40 first molars on the stone casts were prepared for all-ceramic restorations, scanned again, and virtually restored with a full veneer crown using a biogeneric tooth algorithm. For comparison of original and virtually restored teeth, orthographic measurements were performed on the cusp tip configurations from the central pits. The measurements were compared using the concordance correlation coefficient (CCC). For maxillary molars, the ranges of CCC were 0.040 to 0.566 in linear, 0.127 to 0.509 in area, and -0.114 to 0.327 in angular measurements. For mandibular molars, the ranges of CCC were 0.104 to 0.555 in linear, 0.183 to 0.597 in area, and 0.030 to 0.396 in angular measurements. The reproducibility of automatic occlusal construction was relatively low. There is a need for improvement in the biogeneric tooth algorithms to enhance the accuracy of restoring to the original occlusal tooth form in cases of full veneer crown preparation.