[Effect of 4 kinds of prosthodontic materials on masticatory and gingival function].

PURPOSE: To investigate the effect of 4 kinds of prosthodontic materials on masticatory and gingival function. METHODS: A total of 167 patients with dental defects who underwent prosthodontic treatment from October 2019 to January 2022 were collected. They were randomly divided into 4 groups with 41 cases in the pure titanium group, 40 cases in the cobalt-chromium alloy group, 43 cases in the nickel-chromium alloy group and 43 cases in the zirconium dioxide group. The curative effect and satisfaction degree after 6 months of treatment in 4 groups were recorded and compared. The masticatory function (chewing efficiency, bite force), gingival function[plaque index(PLI), gingival index(GI) and sulcus bleeding index(SBI)], gingival crevicular fluid inflammation-related indicators[tumor necrosis factor alpha(TNF-α), interleukin-6(IL-6), aspartate aminotransferase(AST) and alkaline phosphatase (alkaline phosphatase, ALP)] before and after treatment were measured and compared in 4 groups. Statistical analysis was performed with SPSS 20.0 software package. RESULTS: There was no significant difference in curative effect in 4 groups(P＞0.05). Before and after treatment, there was no significant difference in mastication efficiency and bite force in 4 groups(P＞0.05). Before treatment, there was no significant difference in PLI, GI, SBI, gingival crevicular fluid weight, TNF-α, IL-6, AST and ALP in gingival crevicular fluid in 4 groups(P＞0.05). Compared with before treatment, PLI, GI and SBI in 4 groups were decreased after treatment (P＜0.05), and the decrease was in the order of cobalt-chromium alloy group≈nickel-chromium alloy group＜pure titanium group＜zirconia dioxide group. Before treatment, there was no significant difference in the weight of gingival crevicular fluid, TNF-α, IL-6, AST and ALP in gingival crevicular fluid in 4 groups(P＞0.05). The crevicular fluid weight, TNF-α, IL-6, AST and ALP in gingival crevicular fluid were significantly increased(P＜0.05), and the increase was in the order of zirconia group＜pure titanium group＜cobalt-chromium alloy group≈nickel-chromium alloy group. There was no significant difference in restoration integrity and color satisfaction in 4 groups(P＞0.05), but there was significant difference in marginal fitness and sensitivity satisfaction in 4 groups(P＜0.05). CONCLUSIONS: Pure titanium, cobalt-chromium alloy, nickel-chromium alloy and zirconium dioxide can be used for the treatment of dentition defects, and they all can obtain satisfactory chewing function. In addition, zirconium dioxide restoration has the effect of improving gingival function and inflammation-related indicators of gingival crevicular fluid with a broader application prospect.

[Estimation of the optically active substances in case II water of the lower Jinjiang River based on the bio-optical model].

The water's Inherent Optical Properties (IOPs), including absorption and scattering coefficients of water components, are the essential parameters for bio-optical model and retrieval of water quality using the semi-analytical method. Nevertheless, the application of the bio-optical model in river water studies is still very rare. Therefore, taking the lower Jinjiang River of Fujian, SE China as an example, this study measured and calculated the bio-optical properties of river water and concentrations of optically active substances based on in situ water samples collected from river in 2007. It shows that R(0(-))753, R(0(-))702/R(0(-))680 and R(0(-))670/R(0(-))423 can be used to estimate total suspended solids (TSS) concentration, phytoplankton pigment (PP) concentration and the CDOM absorption at 440 nm, respectively. The determination coefficients (R2) of the retrieval model of TSS, PP and CDOM are 0.953, 0.8205 and 0.6213, respectively. The corresponding relative errors of the models (RE) are 6.1%, 21.87% and 22.18%. The results show that the model for estimating TSS can achieve the highest accuracy, the PP-estimating model has the second highest accuracy and the CDOM-estimating model has the lowest. The relatively lower concentration of phytoplankton pigments, narrow characterized spectral range of CDOM and influence of CDOM's R(0(-)) by TSS and PP within this spectral range contributed to their relatively lower accuracy.