Construction of Comprehensive Ability Evaluation Index System for Food and Drug Inspection and Testing Institutions in Guangxi Zhuang Autonomous Region / 中国药房

OBJECTIVE:To provide unified standard for assessing the comprehensive ability of food and drug inspection and testing institutions in Guangxi Zhuang autonomous region. METHODS:The comprehensive ability evaluation index system for food and drug inspection and testing institutions in Guangxi Zhuang autonomous region was drafted by literature review. Indexes of the evaluation index system were determined by Delphi expert consultation,and the weights were calculated by analytic hierarchy pro-cess (AHP). RESULTS:Literature review and expert consultation had constructed the comprehensive ability evaluation index sys-tem for food and drug inspection and testing institutions in Guangxi Zhuang autonomous region,including 6 first-level indexes,16 second-level indexes and 35 third-level indexes. AHP had determined the weights of indexes at all levels,and the weights of the 6 first-level indexes as basic conditions,management system,testing ability,work performance,scientific research and satisfaction degree,were respectively 0.1898,0.1233,0.2280,0.1915,0.1551 and 0.1124,in which testing ability held the highest weight. CONCLUSIONS:A set of scientific and suitable evaluating index system for food and drug inspection and testing institu-tions in Guangxi Zhuang autonomous region has been constructed,and the weights of indexes at all levels have been determined, which can provide clear and unified standard for conducting comprehensive ability system evaluation in each inspection and testing institution in Guangxi Zhuang autonomous region.

Analysis of nutritional status in fragile fracture in hospitalized elderly patients / 中国基层医药

Objective To evaluate the relationship between fragile fracture sites in hospitalized geriatric and nutritional status.Methods On the basis of whether the fracture,293 cases were divided into fracture group(n =140)and normal control group(n =153),51 males(36.4%)and 89 females(63.6%)in 140 fracture patients. Results The age was (74.04 ±8.58)years in the fracture group,that in the normal control group was (74.77 ± 8.14)years,there was statistically significant difference between the two groups(t =-0.743,P >0.05).The femoral neck fracture was 51 cases(36.4%)and intertrochantetic fracture was 57 cases(40.7%),and other was 32 cases (22.8%).The patients were divided into the two groups according to the age:60 ~75 years group(n =62)and >75 years group(n =78),femoral neck fracture was 37.2%,and intertrochantetic fracture was 52.6% in the group that more than 75 years old,which were 35.5% and 25.8%,respectively in 60 ~75 years group,there was statistically significant difference between the two groups(χ2 =18.337,P 0.05).Conclusion The proportion of intertrochantetic fracture and femo-ral neck fracture were higher in hospitalized elderly patients,and malnutrition,such as lower hemoglobin,lower serum albumin,lower weight,and lower BMI were,important factors in the fragile fracture in the geriatric inpatients.

Effect of different dentin cleaning agents on the bond strength of self-adhesive resin cement to dentin / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This study aims to evaluate the bond strength of a self-adhesive resin cement to dentin by ethylene diamine tetraacetic acid (EDTA) and NaClO.</p><p><b>METHODS</b>Twenty-seven freshly extracted non-carious human premolars were prepared to expose the buccal dentin and randomly divided into three groups: control group (A group), EDTA group (B group) and NaClO group (C group). All teeth were bonded to dentin using a self-adhesive resin cement after the teeth in the A group were processed with distilled water. The B and C group were processed with 3%EDTA and 1%NaClO, respectively. After 24 hours at 37 °C water, the shear bond strengths of the twenty-four specimens were measured. All statistical analysis was performed using SPSS 17.0 software package. Each fractured specimen was examined under dental microscope. Three new specimens were cut, and the morphologies of the cement-dentin interface were observed under scanning electron microscope (SEM).</p><p><b>RESULTS</b>The shear bond strength in the A group, B group and C group was (8.55±0.63), (8.47±0.56) and (12.97± 0.59) MPa, respectively. The difference between A group and B group was no statistically significant (P>0.05), whereas the difference between C group and B group (or A group) was statistically significant (P<0.05). SEM observation of the cement-dentin interface in the C group showed good adaptation, but resin tags were not observed. The other two groups showed poor bonding interface. Most of the fractured adhesive dentin surfaces exhibited cohesive failure in the A group and B group. All the fractured adhesive dentin surfaces exhibited cohesive failure in the C group.</p><p><b>CONCLUSION</b>1% NaClO can increase the bond strength of self-adhesive resin cement to dentin, but 3%EDTA has no effect.</p>

Study on the effect of different impression methods on the marginal fit of all-ceramic crowns / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of three different impression methods on the marginal fit of all-ceramic crowns. The three methods include scanning silicone rubber impression, cast models, and direct optical impression.</p><p><b>METHODS</b>The polymethyl methacrylate (PMMA) material of a mandibular first molar in standard model was prepared with 16 models duplicated. The all-ceramic crowns were prepared using three different impression methods. Accurate impressions were made using silicone rubber, and the cast models were obtained. The PMMA models, silicone rubber impressions, and cast models were scanned, and digital models of three groups were obtained to produce 48 zirconia all-ceramic crowns with computer aided design/computer aided manufacture. The marginal fit of these groups was measured by silicone rubber gap impression. Statistical analysis was performed with SPSS 17.0 software.</p><p><b>RESULTS</b>The marginal fit of direct optical impression groups, silicone rubber impression groups, cast model groups was (69.18±9.47), (81.04±10.88), (84.42±9.96) µm. A significant difference was observed in the marginal fit of the direct optical impression groups and the other groups (P<0.05). No statistically significant difference was observed in the marginal fit of the silicone rubber impression groups and the cast model groups (P>0.05).</p><p><b>CONCLUSION</b>All marginal measurement sites are clinically acceptable by the three different impression scanning methods. The silicone rubber impression scanning method can be used for all-ceramic restorations.</p>

Assessment of occlusal vertical dimension using angles: a pilot study / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This study aims to identify highly accurate quantitative methods for evaluating the occlusal vertical dimension by using cephalometric radiographs to analyze the craniofacial hard tissue landmarks in 30 cases with normal occlusions.</p><p><b>METHODS</b>A total of 30 subjects with normal occlusions and aged between 20 and 30 years old were included in the study. Cephalometric radiographs were obtained and analyzed using the Winceph 8.0 measurement software. Landmark points were identified and measured.</p><p><b>RESULTS</b>The mean distribution difference of the center angle (CA) and lower angle (LA) of the face was not statistically significant (t = -1.490, P = 0.147). The CA and LA had a significantly linear correlation (r = 0.976, P = 0.000), and the regression equation was y = 0.298 + 0.997x.</p><p><b>CONCLUSION</b>The CA can be used to assess and quantify the occlusal vertical dimension in clinical practice.</p>

In vitro study on shear bond strength of veneering ceramics to zirconia / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the shear bond strength between veneering ceramic and zirconia core in different all-ceramic systems.</p><p><b>METHODS</b>Twenty disk-shaped specimens with 8 mm in diameter and 3 mm in height for each zirconia system (Lava, Cercon, IPS e.max ZirCAD, Procera) were fabricated respectively and divided into four groups: Lava group, Cercon group, IPS e.max ZirCAD group, Procera group. For each group, 10 specimens were sintered with 1 mm corresponding veneering ceramic, while the other were sintered with 2 mm corresponding veneering ceramic respectively. The shear bond strength and fracture mode of specimens were observed and determined.</p><p><b>RESULTS</b>The values of shear bond strength for Lava, Cercon, IPS e.max ZirCAD and Procera were (13.82 +/- 3.71), (13.24 +/- 2.09), (6.37 +/- 4.15), (5.19 +/- 5.31) MPa in the group of 1 mm thicked veneering ceramics, respectively, while the values in the group of 2mm thicked veneering ceramics were (38.77 +/- 1.69), (21.67 +/- 3.34), (12.70 +/- 4.24), (9.94 +/- 6.67) MPa. The values of Lava and Cercon groups were significantly higher than that of IPS e.max ZirCAD and Procera groups (P < 0.05). And the values of 2 mm thicked veneering ceramic group were significantly higher than that in 1 mm thicked groups (P < 0.05). Adhesive fracture between core and veneering ceramics were observed in the fracture modes of most specimens.</p><p><b>CONCLUSION</b>The shear bond strength of veneering ceramic to the zirconia framework are different from the zirconia system we chose, and the thickness of veneering ceramic has a great impact on its shear bond strength.</p>

Study on disinfection effectiveness and properties of acrylic resin via microwave irradiation sterilization / 中国实用护理杂志

Objective The purpose of this study was to evaluate the disinfection effectiveness and properties of acrylic resin via microwave irradiation. Methods Forty acrylic resin base dentures fabricated in a standardized procedure were chosen and divided into Group A,B,C and D randomly. Group A,B and C were immersed in 200ml distilled water and submitted to microwave irradiation at 700W for 3,4,5 minutes individually. Group D was used as positive control. Bacteria specimens from each group were got for culture and numbers were calculated. Then the four groups were tested for the flexural strength and impact strength by universal test machine before and after microwave irradiation sterilization. Results The germicidal ratio of Group B was more than 90% ,while the ratio of group C was 100%. There was no significant difference in flexural strength and impact strength between group C and group D. Conclusions Microwave irradiation for 5 minutes at 700W produced sterilization of dentures contaminated with all bacteria whereas the denture strength is not affected. Microwave irradiation at 700W solution for 5 minutes was effective to sterilize acrylic resin base dentures.

The effect of TiN coating on retention of conus telescopic crowns after repeated insertion/separation tests / 实用口腔医学杂志

Objective:To evaluate the effect of TiN coating on retentive force of conus telescopic crowns after repeated insertion/separation tests. Methods: Fourteen pairs of standard metal specimens fabricated by precision Computer Numerical Control (CNC) Lathe were randomly divided into experimental group and control group, seven pairs in each group. The external surfaces of inner crowns and internal surfaces of outer crowns of experimental group were coated with a 2.0 μm titanium nitride (TiN) by multi-arc ion plating method. The group without titanium nitride coating was served as control. The retentive forces of two group telescopic crowns was investigated by repeated insertion/separation tests. Statistical analysis of group t-test was performed by SPSS 13.0 software package. Results: The results demonstrated that the initial retentive force of titanium nitride group in our study were lower than that of uncoated titanium nitride group. The retentive forces of two groups gradually decreased depending on the number of insertion/separation cycles and the rate of retention attenuation was found to be statistically significant. It was also shown that the retentive force of titanium nitride coating group began to decrease after 3 000 cycles and declined slowly not only before 3 000 cycles but also after 7 000 cycles. Conclusion: Titanium nitride coating deposited on external surface of inner crowns and internal surface of outer crowns can significantly decrease retention attenuation rate of conus telescopic crowns and maintain persistent retentive force.