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Statement of Problem: Static and dynamic occlusal interference frequently needs to be corrected by selective grinding of the occlusal surface of conventional cast and ceramic-fused-to-metal restorations. CAD/CAM techniques allow control of the dimensional contours of these restorations. However, parameters responsible for the occlusal form need to be determined. In most articulators, these parameters are set as default values. Which technique is best for minimizing the introduction of occlusal interference in restorations has not been determined., Purpose: This study investigated differences in crown structure of a crown designed in static occlusion (STA) with designs adapted for dynamic occlusal interferences. Therefore, values from an optoelectronic registration system (String-Condylocomp, KAVO), an occlusal generated path (OGP) technique and default settings (DEF) were used in the CICERO CAD/CAM system., Material and Methods: Morphology of CON, DEF, and OGP crowns was compared with that of the STA crown with respect to differences in a buccolingual section and frequency of occlusal distances in an interocclusal range of 1 mm, measured from the occlusal surface of the crown., Results: All crown types fulfilled the esthetic and morphologic criteria for restorations in clinical dentistry. Difference in the morphology of the OGP crown, compared with that of the STA crown, was greater than that for the CON and DEF crowns. These differences were seen especially in the distobuccal part of the occlusal surface; however, the number of occlusal contacts was considered sufficient to stabilize occlusion., Conclusion: Functional occlusion, adapted to dynamic occlusion in a CICERO crown for the first mandibular molar, can be obtained using data acquired with the String-Condylocomp registration system. The OGP technique was preferred to other techniques because of the simplicity of the technique for eliminating potential problems with opposing teeth during motion. However, this is achieved at the cost of fewer points of contact during occlusion than with the CON crown.

The force-deformation characteristics of two artificial test foods (Optosil and Optocal) for measurements of food comminution during mastication were investigated in a bite simulator and compared with those of carrots and peanuts. The influence of cusp geometry was evaluated by use of a flat plate and three cusp forms. The forces at the yield point were lower for Optocal than for Optosil artificial test food. The forces needed for Optocal overlapped those needed for carrots and peanuts. The natural foods showed more variation in the force and percentage of deformation at the yield point than the artificial foods. The artificial foods reflected the differences in cusp form better than did the natural foods. The use of artificial foods fulfills a need for standardization and warrants consideration in studies of mastication.

This study investigated the relationships between the ability of 38 patients with complete dentures to comminute a tough artificial test food and their answers to questions about the chewing experience. Also, clinical assessments were made of denture quality and oral conditions. Significant but weak relationships were found between the ability to comminute the test food and the subjective chewing experience as well as the degree of resorption of the mandibular residual ridge. Masticatory ability is conceivably determined by many other factors as well. Results indicate that dentists cannot rely on asking denture wearers about chewing problems and clinical responses with respect to oral conditions and denture quality for predicting those patients' masticatory abilities. The ability of wearers of complete dentures to comminute tough foods should be determined individually by a series of chewing tests.