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Objective To determine whether chewing side preference is related to handedness and lateral asymmetry of occlusal characteristics, muscular force and temporomandibular disorders (TMD) in a dentate population. Design One hundred and seventeen dentate adults participated in this cross-sectional study. Static and dynamic occlusal characteristics were determined at the maximal intercuspal position and at the lateral excursions by scanning interocclusal records and analysing them using image software. Unilateral maximum bite force and finger–thumb grip force were measured by means of a gnathodynamometer. TMD were assessed according to the Research Diagnostic Criteria for TMD. Chewing side preference and masticatory laterality were determined by observing the jaw's movement while each subject chewed silicone. Asymmetry or side difference of the variables was calculated. Correlation between side difference variables and masticatory laterality was studied using Spearman correlation coefficient. Results Fifty-nine subjects chewed on the right, 15 on the left and 43 chewed on both sides. There was no relationship between preferred chewing side and handedness, lateral asymmetry of TMD or side difference in finger–thumb grip force. Significant and positive correlations were observed between masticatory laterality and side differences in bite force and side differences in occlusal contact area at intercuspal position (P Conclusions Chewing side preference in a dentate population is related to lateral asymmetry of bite force and asymmetry of occlusal contact area at the intercuspal position but not to handedness.

This study evaluated the effects of recasting on high noble, noble, and nickel-based alloys, as well as on titanium. Four specimens of each material were cast and recast 7 times. Chemical composition, microstructure, microhardness, and ion release were determined before and after the first cast and following each recast. Zinc and tin concentrations in the high noble alloy decreased significantly with recasting; consequently, the release of these ions decreased as well. A significant increase in Vickers hardness appeared in the fifth recast in both the high noble alloy and titanium. The noble alloy and the nickel-based alloy demonstrated great stability after 7 recasts. The results suggest not recasting titanium.

This study assessed the duration of different phases of the chewing cycle and the height of the masticatory cycle in relation to the type of lateral guidance.Fifty-three subjects with the same type of lateral guidance on both sides were categorized into 3 groups: anterior protected articulation, canine protection, and group function. Overbite was measured clinically. Border jaw movements were recorded using a Sirognathograph, and the lateral guidance angle in the frontal plane was measured. Jaw movements during unilateral chewing of peanuts were recorded on the frontal plane using the Sirognathograph connected to an electrocardiograph used for transcription. A single masticatory cycle was divided into opening, closing, and occlusal-level phases. Masticatory parameters were analyzed by one-way analysis of variance, correlations, the paired Student t test, and multiple linear regression.Women showed significantly longer total cycle duration than men. Subjects with canine protection showed the highest lateral guidance angle and the highest chewing cycle duration. Subjects with anterior protected articulation exhibited significantly longer occlusal-level phases. Fifty-nine percent of the variation in duration of the occlusal-level phase can be explained by the type of lateral dental guidance, gender, and lateral guidance angle. Only overbite was a predictor of height of mastication.The type of lateral guidance, gender, and frontal guidance angle are correlated with the duration of the occlusal-level phase during unilateral chewing of peanuts. The height of mastication cannot be explained by the type of lateral guidance.

Occlusal adjustment of ceramic restorations may be necessary to correct interferences. A rough surface may abrade opposing tooth or restorative materials, thereby increasing plaque accumulation. The aim of this study was to compare the effect of four finishing systems and diamond paste on ceramic roughness.Forty ceramic disks were distributed into four randomized groups. The initial roughness of all samples was increased with a diamond bur. Samples in group 1 were finished with white silicon and black rubber; group 2 samples were finished with Shofu rubbers; group 3 samples were finished with diamond burs; and group 4 samples were finished with Sof-Lex disks. All samples were then polished by Yeti diamond paste. The surfaces were characterized by means of a surface roughness analyzer. The parameters Ra, Rpm, and Rz were determined. Four roughness recordings were made before and after diamond bur finishing, and before and after Yeti paste polishing. ANOVA was used to test the significance of differences between groups at each stage of the procedures.All four methods reduced the average roughness of the samples. The most effective system was Sof-Lex disks. Diamond paste can round the profile shape and reduce the height of maximum peaks of the surface, but it may not improve the average roughness.All systems tested reduced the roughness of ceramic samples, but the Sof-Lex disk finishing system may be more efficient than other methods. The efficiency of the diamond paste is not clear.