The Effect of Hydrofluoric Acid Etching Duration on the Surface Micromorphology, Roughness, and Wettability of Dental Ceramics

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A Functional Stress Analysis in the Maxillary Complete Denture Influenced by the Position of Artificial Teeth and Load Levels: an In-vitro Study

The fracture of complete dentures fabricated using Polymethyl methacrylate resin constitutes a challenge to the clinician and remains an unresolved problem. To determine whether gradual increase in load or different posterior teeth positions in maxillary denture would influence the pattern of stress. Two groups of maxillary dentures were fabricated with different posterior teeth positions (Group I with teeth on the crest of the ridge; Group II with buccal to the crest of the ridge.) using casts prepared from prefabricated edentulous molds, with 5 dentures in each group. Two strain gauges were cemented on to the midline of each denture, one on the anterior palatal area and other on the posterior palatal area. The dentures were loaded from 0 to 110 N in steps of 10 N, and the strains induced were measured. Differences of the stress magnitudes between the 2 groups were statistically analyzed using Mann–Whitney U test. The anterior palatal area of the maxillary denture was dominated by a tensile stress, which was greater in the group II than in group I. The posterior palatal area was dominated by compressive stress but the outer placement of the maxillary teeth caused a significant decrease in the compressive stress. The high anterior tensile stress with compressive stress in the posterior palatal area during loading may be responsible for denture base fractures that initiate from the anterior palatal area. The buccal placement of posterior teeth may play a role in the fatigue fracture of the maxillary denture

Tooth Color as a Predictor of Oral Health‐Related Quality of Life in Young Adults

PURPOSE: Smiling plays an important role in social interaction. The purpose of this research was to explore the extent to which objective parameters of color of one's own teeth affected the social and emotional dimensions of young adults' lives. MATERIALS AND METHODS: The sample included 134 subjects- students of the University of Rijeka, Croatia (65% female) aged 19 to 28 years (median 21). All subjects had six intact maxillary anterior teeth without restorations or severe malocclusions and healthy gingiva with no signs of inflammation. Tooth color was assessed intraorally using a spectrophotometer. Lightness, chroma, and translucency of the right maxillary central incisors (the reference teeth) were calculated and used for analysis. Subjects reported dimensions of their oral health-related quality of life (OHRQoL) using the Oral Health Impact Profile (OHIP), Orofacial Esthetic Scale (OES), and the Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ). Linear relationships between elements of tooth color and OHRQoL were explored using Pearson correlations. Multiple linear regression, while controlling for the influence of age and gender, was also calculated. ANOVA with a Tukey post hoc test was employed to test whether nonlinear relationships existed between OHRQoL and categories of color elements. RESULTS: Dental self-confidence, esthetic concerns, orofacial appearance, social impact and psychological impact were not related to lightness, chroma, or translucency of the subjects' teeth. Neither linear nor nonlinear relationships were detected between those aspects. Satisfaction with smile esthetics was only related to translucency where subjects with moderate translucency were least likely to be satisfied (p = 0.033). Women tended to report greater psychosocial impacts than men (p < 0.05), regardless of their tooth color. CONCLUSION: According to the results of this study objective, measurable, quantitative parameters of tooth color did not accurately predict psychosocial dimensions of OHRQoL in dentate young adults