Determining the relationship between food texture and dental condition: First bite and chewing aspects.

Among the sensory properties of foods, texture perception is a complex modality due to catastrophic changes during eating. Relating dental conditions and capacity of texture sensation are still paucities in the literature. Different dental areas emphasize the difference in texture sensation. Anterior teeth are responsible for biting, ripping or tearing; while posterior teeth are chewing and grinding. Hence, the absence of any is expected to cause disruptions in mastication functions. The hypothesis of the present study was dental loss or missing is a burden for hardness perception for first-bite and twice chewed for anterior and posterior teeth, respectively. Patient groups were divided according to anterior-posterior tooth deficiencies and hardness sensation was assessed at first bite and twice chewed modal food (white cheese) with various hardness levels obtained with different fat content. The modal food was tested for its physicochemical, textural and sensory properties with dental assessment. Findings suggest that first-bite hardness judgements were not affected by the loss of the anterior. Oppositely, twice chewed hardness has a significant effect on the loss of a posterior tooth. These findings can indicate to future researchers to be tested according to their dental status especially if chewing is necessary for their sensory tests.

The effect of nonthermal argon plasma surface treatment on the fracture resistance of monolithic zirconia restorations containing tetragonal and cubic grains.

PURPOSE: The aim of this study was to investigate the effect of nonthermal argon plasma (NP) surface treatment on the fracture resistance of monolithic zirconia restorations with different microstructures. METHODS: Twenty restorations were prepared from each of two tetragonal and two cubic zirconia materials (80 restorations in total). The restorations were then divided into two subgroups (n = 10) for each material according to the surface treatment applied: air abrasion or NP. The surface topography of the treated groups was examined using a scanning electron microscope. All restorations were fixed to metal dies with resin cement, subjected to thermal cycling, and then underwent fracture resistance testing with a universal testing device. Two-way ANOVA and Bonferroni tests were used for statistical analysis of the data (α = 0.05). RESULTS: The type of surface treatment and the type of zirconia material were shown to significantly affect the fracture resistance of the restorations. The air-abraded groups showed significantly higher fracture resistance (N) than the NP groups (P < 0.001). CONCLUSION: The results of this study suggest that air abrasion surface treatment has a more favorable effect on the fracture resistance of tetragonal and cubic zirconia restorations than NP surface treatment.