No abstract

Masticatory performance is the outcome of a complex interplay of several factors. This study was carried out to determine the relationship between masticatory performance and several muscular‐related and occlusion‐related factors in a population with a full or near‐full complement of natural teeth. One‐hundred dentate young adults participated in this cross‐sectional study. Maximum muscular force with jaw, hand, tongue, and cheek were measured by means of a gnatodynamometer. Occlusal contact area and number of teeth in contact were determined in the maximal intercuspal position and in a 1.5‐mm right and left lateral excursion by means of interocclusal registrations that were scanned and analysed using image software. Masticatory performance was determined by sieving the Optosil particles resulting from 20 chewing cycles. Stepwise multiple linear regression analysis showed that the maximum bite force in the region of the first molar had the best correlation with masticatory performance and explained 36% of its variation. Static occlusion characteristics such as occlusal contact area, the lack of lateral crossbite and the number of anterior teeth in contact explained an additional 9% of the variation in masticatory performance. These findings suggest that variables related to dynamic occlusion or tongue or cheek force do not enhance the prediction of masticatory performance.

Purpose: This study evaluated the effect of matrix type on the surface roughness of resins for provisional crowns and fixed partial dentures. Materials and Methods: Ninety specimens of two acrylic resins (Trim II, Tab2000) and one bis-acryl composite (Protemp II Garant) were fabricated using one of three matrices: irreversible hydrocolloid (Cavex CA37), poly(vinyl siloxane) (Aquasil) or vacuum-formed matrix (Bio-flow Hard). The sample size for each resin-matrix combination was 10. The vestibular face of one natural maxillary central incisor was used as a model to fabricate all the specimens, following the custom fabrication technique. The average roughness measurements, Ra (μm), were obtained using a profilometer, and the data were analyzed using Kruskal-Wallis and Mann-Whitney U-tests. The results were contrasted against the surface roughness of the tooth using a one-sample t-test.