High flexural strength is a desirable property for denture base resins. Currently there is a lack of published studies evaluating the physical properties of newer denture bases such as the CAD/CAM milled bases. The purpose of this study was to compare the flexural strength of three different denture base resins fabricated by compression molding, injection molding, and pre-polymerized CAD/CAM milling. Three groups of ten PMMA acrylic denture base resins were processed into rectangular plates for total sample size of thirty (n=30). The groups differed in their method of processing and resin composition. The three groups were injection molded (SR-Ivocap High Impact, Ivoclar Vivadent), compression molded (Lucitone 199, Dentsply), and pre-polymerized CAD/CAM milled resins (Avadent Digital Dentures). Following storage in water for one week, flexural strength was measured using a 3-point bend test until failure. Kruskal-Wallis and Mann-Whitney tests were used for statistical comparison between groups. Significant differences in flexural strength was observed among the groups tested. The flexural strength of the pre-polymerized CAD/CAM milled acrylic resin group was higher than that of conventional method groups of compression molded and injection molded. The compression molded group exhibited higher flexural strength than the injection molded group. The results suggest that pre-polymerized milled denture bases may be a useful alternative to conventionally processed denture bases in situations where increased bending forces are anticipated.

No abstract

No abstract

No abstract

Dental implants have become a widely used dental treatment approach. It is important to identify factors that can be detrimental to dental implants and the peri-implant complex. There is controversy regarding whether occlusion plays a role in the implant and peri-implant condition. The present study aims to review the scientific literature regarding this topic. Animal and human studies, and previous reviews on the topic are included and presented. There is a wide heterogeneity among study designs. Several articles demonstrated that occlusion and occlusion overload could detrimentally affect the peri-implant condition, while other articles did not support these results. More studies are needed to help understand the mechanisms by which occlusion might play a role in the peri-implant condition.

No abstract

No abstract

Relatively few assessments of cranial biomechanics formally take into account variation in the material properties of cranial cortical bone. Our aim was to characterize the elastic properties of chimpanzee craniofacial cortical bone and compare these to the elastic properties of dentate human craniofacial cortical bone. From seven cranial regions, 27 cylindrical samples were harvested from each of five chimpanzee crania. Assuming orthotropy, axes of maximum stiffness in the plane of the cortical plate were derived using modified equations of Hooke’s law in a Mathcad program. Consistent orientations among individuals were observed in the zygomatic arch and alveolus. The density of cortical bone showed significant regional variation (P<0.001). The elastic moduli demonstrated significant differences between sites, and a distinct pattern where E3 >E2 > E1. Shear moduli were significantly different among regions (P<0.001). The pattern by which chimpanzee cranial cortical bone varies in elastic properties resembled that seen in humans, perhaps suggesting that the elastic properties of craniofacial bone in fossil hominins can be estimated with at least some degree of confidence.