PURPOSE: . This study aimed to compare the wear depth and volume loss of 3D-printed resin denture teeth with prefabricated and milled acrylic denture teeth under chewing simulation. MATERIALS AND METHODS: . Four groups of denture teeth (n = 9) were evaluated: prefabricated acrylic teeth (PT), milled acrylic teeth (MT), 3D-printed methacrylate-based resin teeth (3DT), and glazed 3D-printed resin teeth (3DT+G). Samples were embedded in self-curing resin, and antagonists were fabricated from the same materials. A chewing simulator was utilized to apply a cyclic occlusal load of 49.05 N (5 kg) for 120,000 cycles in distilled water. Wear depth (μm) and volume loss (mm3 ) were measured using a 3D laser profilometer. Surface morphology was qualitatively analyzed via scanning electron microscopy (SEM). Data normality was verified, and statistical significance was determined using one-way ANOVA followed by Tukey’s HSD test (α=0.05). RESULTS: . Significant differences in wear depth and volume loss were observed among the groups (P < .05). No significant differences were found between PT and MT, or between 3DT and 3DT+G. However, the 3DT and 3DT+G groups exhibited significantly lower wear depth and volume loss compared to the PT and MT groups (P < .05). SEM analysis revealed that the PT group displayed a more uniform and homogenous surface morphology compared to the other groups, while 3DT+G showed evidence of glaze depletion within the wear facets. CONCLUSION . 3D-printed resin denture teeth demonstrated superior wear resistance compared to prefabricated and milled alternatives under simulated chewing conditions. Furthermore, the application of a 50 µm surface glaze did not significantly enhance wear resistance of the 3D-printed resin.

PURPOSE: The aims of this study were to investigate mechanical properties and hydrothermal degradation behaviour of the cubic-containing translucent yttrium oxide stabilized tetragonal zirconia polycrystal (Y-TZP). MATERIALS AND METHODS: Four groups of Y-TZP (T, ST, XT, and P), containing different amount of cubic crystal, were examined. Specimens were aged by autoclaving at 122°C under 2 bar pressure for 8 h. Phase transformation was analyzed using X-ray diffraction (XRD) to measure phase transformation (t→m). KruskalWallis test was used to determine the difference. Surface hardness, biaxial flexural strength, and fracture toughness in values among the experimental groups and verified with Wilcoxon matched pairs test for hardness values and Mann Whitney U for flexural strength and fracture toughness. RESULTS: XRD analysis showed no monoclinic phase in XT and P after aging. Only Group T showed statistically significant decreases in hardness after aging. Hydrothermal aging showed a significant decrease in flexural strength and fracture toughness in group T and ST, while group XT and P showed no effect of aging on fractural strength and fracture toughness with P<.05. CONCLUSION Hydrothermal aging caused reduction in mechanical properties such as surface hardness, biaxial flexural strength, and fracture toughness of Y-TZP zirconia. However, cubic-containing zirconia (more than 30% by volume of cubic crystal) was assumed to have high resistance to hydrothermal degradation.Clinical significance: Cubic-containing zirconia could withstand the intraoral aging condition. It could be suggested to use as a material for fabrication of esthetic dental restoration.

This clinical report presents the clinical appearance and treatment approach in a case of excessive anterior teeth erosion resulted from swimming in a poorly-chlorinated swimming pool. Clinical findings revealed tooth sensitivity, severe enamel erosion resembling veneer preparations, and the presence of anterior open bite. A novel hybrid ceramic (Vita Enamic) was chosen for fabricating full-coverage crowns for this patient. After 6-months follow-up, the tooth sensitivity disappeared and the patient was satisfied with esthetic outcome. The hybrid ceramic restorations can be recommended with no complications.
Ceramics* ; Crowns ; Dental Enamel ; Follow-Up Studies ; Humans ; Open Bite ; Swimming Pools ; Swimming* ; Tooth ; Tooth Erosion*