[Research progress on the low-temperature degradation of zirconia in prosthetic dentistry]

Zirconia is widely used in the field of dentistry because of its superior mechanical and esthetic characteristics. However, the tetragonal zirconia polycrystal restorations commonly used in clinics will degrade at low temperatures in the oral environment, resulting in increased surface roughness, microcracks, and decreased mechanical properties. Low-temperature degradation of zirconia can be affected by grain size, stress, stabilizer content and type, surface treatment, sintering conditions, and other factors. Through a literature review and analysis, this review summarizes the research progress on the low-temperature degradation of zirconia in prosthetic dentistry to provide references for the improvement of zirconia in clinical and research applications.

[Clinical analysis of 33 cases of chronic liver diseases overlapping with CMV infection]

Objective: To understand the clinical features and outcomes of chronic liver diseases overlapping with CMV infection. Methods: Clinical characteristics, treatment and outcome of patients of chronic liver diseases overlapping with CMV infection were analyzed retrospectively. T-test was used for measurement data and χ (2) test was used for count data. All measurement data were expressed by (x ± s). P > 0.05 was not determined as significant. P < 0.05 was regarded as statistically significant. Results: Chronic liver diseases overlapping with CMV infections had similar clinical features. Etiopathogenic treatment + symptomatic supportive treatment + CMV overlapping infection treatment (including antiviral therapy, corticosteroids consideration, clearing heat and traditional Chinese choleretic medicine, etc) were the primary principles of therapy. The incidence of cytomegalovirus infection accounted for 4.125% during the corresponding hospitalization period. Cytomegalovirus infection had relatively caused liver function damage in patients with milder clinical symptoms and signs. Biochemical indicators before and after treatment showed that there was no significant difference in total bilirubin (TBil) before (262.93 ± 178.944) μmol/L and after one week of treatment (245.08 ± 179.332) μmol/L (P > 0.05). However, when TBIL was compared with three (156.58 ± 147.461) μmol/L and four weeks (103.39 ± 102.218) μmol/L) of treatment, the decrease was significant (P < 0.05, P < 0.01). Alanine aminotransferase (ALT) after one week (293.57 ± 467.438) U/L (P < 0.01) of treatment was significantly lower than before treatment (782.34 ± 828.801) U/L. Gamma-glutamyl transferase (GGT) after treatment (202.52 ± 155.174)U/L was significantly lower than before treatment(280.69 ± 205.619)U/L). Total bile acid (TBA) was increased after treatment (198.04 ± 155.174)μmol/L, when compared with that of before treatment (62.93 ± 178.944)μmol/L. Biochemical indicators of liver diseases had shown typical features of cholestasis, and the slow and reduced flow of bile acid was tracked and observed. Compared with the advanced group (182.45 ± 214.169) umol/L, the total bilirubin in inflammation group (50.36 ± 26.282) umol/L was decreased (P < 0.05). Moreover, advanced group (122.18 ± 106.780) umol/L (P < 0.05) had elevated total bile acid normalization rate than that of bile acid group (54.82 ± 56.123) umol/L, and the inflammatory phase had significantly better outcome than those with advanced-stage. Conclusion: Chronic liver diseases overlapping with cytomegalovirus infection has a good therapeutic outcome in the inflammatory phase, but in the advanced-stage; the therapeutic efficacy and outcome is poor and perilous.