Effect of K2O addition on the crystallization property of dental glass-ceramics / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the effect of K2O addition on the crystallization property of dental glass-ceramics in the Li2O-SiO2-Al2O3-P2O5-ZnO system.</p><p><b>METHODS</b>Different content of K2O was added into Li2O-SiO2-Al2O3-P2O5-ZnO glass system. The heat-treated system of the glass-ceramics was determined by differential thermal analyses (DTA), then the crystallization components and the microstmcture of the glass-ceramics with different content of K2O were investigated from X-ray diffraction (XRD) analyses and scanning electron microscopy (SEM).</p><p><b>RESULTS</b>Addition of K2O helped to reduce the viscosity of the glass system and improved crystallization. More lithium disilicate crystals appeared after heated-treatment of the glass system which contained 5.3 wt% addition of K2O, and the homogeneously lath-shaped crystals were 4 gm in length.</p><p><b>CONCLUSION</b>Certain content of K2O can improve the crystallization property of dental glass-ceramics in the Li2O-SiO2-Al2O3-P2O5-ZnO system.</p>

Energy relieving effect of different thickness of mucosa beneath mandibular complete denture / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To analyze the energy relieving effect of different thickness of mucosa beneath mandibular complete denture and try to analyze clinical question of prosthodontics using energy analysis methods.</p><p><b>METHODS</b>A 3-DFE model of the mandibular complete denture and its supporting tissue were set up. Their elastic deformed energy and the percentage in the whole system were respectively calculated when mucosal thickness was different.</p><p><b>RESULTS</b>The percentage of mucosal elastic deformed energy grew from 44.53% to 52.91% and 57.91% with its different thickness under static loads.</p><p><b>CONCLUSIONS</b>The energy relieving effect of mucosa grows with its thickness and the approach of energy analysis is one of effective method on oral biomechanics questions.</p>