OBJECTIVETo compare the surface roughness of nanofilled dental composite resin and microhybrid composite resins after curing and polishing.

METHODSA nanofilled composite (Z350) and 4 microhybrid composites (P60, Z250, Spectrum, and AP-X) were fabricated from the lateral to the medial layers to prepare 8 mm×8 mm×5 mm cubical specimens. The 4 lateral surfaces of each specimens were polished with abrasive disks (Super-Snap). Profilometer was used to test the mean surface roughness (Ra) after polishing.

RESULTSP60 had the lowest Ra (0.125∓0.030 µm) followed by Z250 and Spectrum. The Ra of Z350 (0.205∓0.052 µm) was greater than that of the other 3 resins, and AP-X had the roughest surfaces. Under scanning electron microscope, the polished faces of P60 resin were characterized by minor, evenly distributed particles with fewer scratches; the polished faces of Z350 presented with scratches where defects of the filling material could be seen.

CONCLUSIONThe nanofilled composite Z350 has smooth surface after polishing by abrasive disks, but its smoothness remains inferior to that of other micro-hybrid composite resins.

Objective To compare the surface roughness of nanofilled dental composite resin and microhybrid composite resins after curing and polishing. Methods A nanofilled composite (Z350) and 4 microhybrid composites (P60, Z250, Spectrum, and AP-X) were fabricated from the lateral to the medial layers to prepare 8 mm×8 mm×5 mm cubical specimens. The 4 lateral surfaces of each specimens were polished with abrasive disks (Super-Snap). Profilometer was used to test the mean surface roughness (Ra) after polishing. Results P60 had the lowest Ra (0.125 ± 0.030 μm) followed by Z250 and Spectrum. The Ra of Z350 (0.205±0.052μm) was greater than that of the other 3 resins, and AP-X had the roughest surfaces. Under scanning electron microscope, the polished faces of P60 resin were characterized by minor, evenly distributed particles with fewer scratches;the polished faces of Z350 presented with scratches where defects of the filling material could be seen. Conclusion The nanofilled composite Z350 has smooth surface after polishing by abrasive disks, but its smoothness remains inferior to that of other micro-hybrid composite resins.

Objective To evaluate the effect of thermal cycling on surface microstructure of different light-curing composite resins. Methods A nanofilled composite (Z350) and 4 microhybrid composites (P60, Z250, Spectrum, and AP-X) were fabricated from lateral to center to form cubic specimens. The lateral surfaces were abrased and polished before water storage and 40 000 thermal cycles (5/55℃). The mean surface roughness (Ra) were measured and compared before and after thermal cycling, and the changes of microstructure were observed under scanning electron microscope (SEM). Results Significant decreases of Ra were observed in the composites, especially in Spectrum (from 0.164±0.024μm to 0.140±0.017μm, P<0.001) and Z250 (from 0.169 ± 0.035μm to 0.144 ± 0.033μm, P<0.001), whose Ra approximated that of P60 (0.121 ± 0.028μm) with smoothly polished surface. SEM revealed scratches and shallower pits on the surface of all the 5 resins, and fissures occurred on Z350 following the thermal cycling. Conclusions Water storage and thermal cycling may produce polishing effect on composite resins and cause fissures on nanofilled composite resins.

Objective To compare the surface roughness of nanofilled dental composite resin and microhybrid composite resins after curing and polishing. Methods A nanofilled composite (Z350) and 4 microhybrid composites (P60, Z250, Spectrum, and AP-X) were fabricated from the lateral to the medial layers to prepare 8 mm×8 mm×5 mm cubical specimens. The 4 lateral surfaces of each specimens were polished with abrasive disks (Super-Snap). Profilometer was used to test the mean surface roughness (Ra) after polishing. Results P60 had the lowest Ra (0.125 ± 0.030 μm) followed by Z250 and Spectrum. The Ra of Z350 (0.205±0.052μm) was greater than that of the other 3 resins, and AP-X had the roughest surfaces. Under scanning electron microscope, the polished faces of P60 resin were characterized by minor, evenly distributed particles with fewer scratches;the polished faces of Z350 presented with scratches where defects of the filling material could be seen. Conclusion The nanofilled composite Z350 has smooth surface after polishing by abrasive disks, but its smoothness remains inferior to that of other micro-hybrid composite resins.

Objective To evaluate the effect of thermal cycling on surface microstructure of different light-curing composite resins. Methods A nanofilled composite (Z350) and 4 microhybrid composites (P60, Z250, Spectrum, and AP-X) were fabricated from lateral to center to form cubic specimens. The lateral surfaces were abrased and polished before water storage and 40 000 thermal cycles (5/55℃). The mean surface roughness (Ra) were measured and compared before and after thermal cycling, and the changes of microstructure were observed under scanning electron microscope (SEM). Results Significant decreases of Ra were observed in the composites, especially in Spectrum (from 0.164±0.024μm to 0.140±0.017μm, P<0.001) and Z250 (from 0.169 ± 0.035μm to 0.144 ± 0.033μm, P<0.001), whose Ra approximated that of P60 (0.121 ± 0.028μm) with smoothly polished surface. SEM revealed scratches and shallower pits on the surface of all the 5 resins, and fissures occurred on Z350 following the thermal cycling. Conclusions Water storage and thermal cycling may produce polishing effect on composite resins and cause fissures on nanofilled composite resins.

Objective To investigate the relationship between the optimal cutoff point of serum homocyste-ine(Hcy)and premature delivery in pregnant women ,and to analyze the influence of Hcy levels on the outcome of preterm infants. Methods Totally 114 cases of pregnant women were chosen as observation group and 103 cases of normal as control group. Hcy,D-D and hypersensitive C reactive protein were detected;analysis of the ROC curve was conducted by using the SPSS 13 software and the risk factors for preterm delivery were analyzed using logistic multivariate regression analysis. Results (1)The levels of Hcy,HS-CRP and D-D in preterm pregnant women were higher than those in control group and the difference was statistically significant (P < 0.05). (2) Logistic regression analysis showed that the relative risk coefficient(OR)of Hcy was 9.736,and the regression equation of premature birth probability was obtained.(3)ROC curve to evaluate the predictive value of Hcy in risk factors of preterm birth was 0.931;when Hcy was 13.8μmol/L,the Youden index was 0.784.(4)Elevated levels of Hcy in preterm women led to a marked increase in the likelihood of SGA. Conclusion When predicting risk factors for preterm birth,the best predictive cutoff value for Hcy is 13.8μmol/L,which is one of the independent risk factors for preterm birth.

Objective:To examine the clinical effect of autologous osteochondral transplantation via biplanar osteotomy for osteochondral lesions of the talus combined with subchondral cysts.Methods:A retrospective analysis of 25 patients who underwent autogenous osteochondral transplantation via biplanar osteotomy for treatment of talus osteochondral injury combined with subchondral cysts at Department of Orthopaedics, First Affiliated Hospital of Xinjiang Medical University from December 2015 to December 2018 were conducted.There were 21 males and 4 females, aged 35.5 years(range: 21 to 47 years).The extent and depth of cartilage damage of patients were evaluated under arthroscopy.The Outerbridge classification of patients were stage Ⅱ-Ⅳ. Through the anterior and medial incision of the medial malleolus, bilateral osteotomy of the medial malleolus was performed. The osteotomy block was turned down to reveal the cartilage damage site. The abnormal cartilage was completely removed and the sclerotic wall of cyst was completely removed with a spatula.Then the healthy cartilage from the same knee joint was transplanted to the talus cartilage damage area. The preoperative and postoperative visual analogue scale(VAS), American Orthopedic Foot Andankle Society-Ankle Hindfoot Scale (AOFAS-AH) and Karlsson-Peterson score and Lysholm score of knee joint were recorded. Data were analyzed by paired-samples t-test.Results:All of patients were followed up for 25.6 months (range: 12 to 48 months) .The VAS decreased from 6.5±1.3 to 1.9±1.3 ( t=8.13, P=0.00) .AOFAS-AH increased from 62.4±3.3 to 88.0±2.4 ( t=-31.51, P=0.00) .Karlsson-Peterson scores increased from 59.8±2.7 to 85.2±3.5 ( t=-25.50, P=0.00) . While there was no statistical different in Lysholm score of knee joint (92.5±1.3 vs. 92.0±1.3, t=1.93, P=0.065) . No complications like infection, translated cartilage necrosis, cycst residual, nonunion, persistent pain in donor site. Conclusion:Autologous osteochondral transplantation via biplanar osteotomy has satisfactory effect for patients with osteochondral lesions of the talus combined with subchondral cysts.

Objective:To examine the clinical effect of autologous osteochondral transplantation via biplanar osteotomy for osteochondral lesions of the talus combined with subchondral cysts.Methods:A retrospective analysis of 25 patients who underwent autogenous osteochondral transplantation via biplanar osteotomy for treatment of talus osteochondral injury combined with subchondral cysts at Department of Orthopaedics, First Affiliated Hospital of Xinjiang Medical University from December 2015 to December 2018 were conducted.There were 21 males and 4 females, aged 35.5 years(range: 21 to 47 years).The extent and depth of cartilage damage of patients were evaluated under arthroscopy.The Outerbridge classification of patients were stage Ⅱ-Ⅳ. Through the anterior and medial incision of the medial malleolus, bilateral osteotomy of the medial malleolus was performed. The osteotomy block was turned down to reveal the cartilage damage site. The abnormal cartilage was completely removed and the sclerotic wall of cyst was completely removed with a spatula.Then the healthy cartilage from the same knee joint was transplanted to the talus cartilage damage area. The preoperative and postoperative visual analogue scale(VAS), American Orthopedic Foot Andankle Society-Ankle Hindfoot Scale (AOFAS-AH) and Karlsson-Peterson score and Lysholm score of knee joint were recorded. Data were analyzed by paired-samples t-test.Results:All of patients were followed up for 25.6 months (range: 12 to 48 months) .The VAS decreased from 6.5±1.3 to 1.9±1.3 ( t=8.13, P=0.00) .AOFAS-AH increased from 62.4±3.3 to 88.0±2.4 ( t=-31.51, P=0.00) .Karlsson-Peterson scores increased from 59.8±2.7 to 85.2±3.5 ( t=-25.50, P=0.00) . While there was no statistical different in Lysholm score of knee joint (92.5±1.3 vs. 92.0±1.3, t=1.93, P=0.065) . No complications like infection, translated cartilage necrosis, cycst residual, nonunion, persistent pain in donor site. Conclusion:Autologous osteochondral transplantation via biplanar osteotomy has satisfactory effect for patients with osteochondral lesions of the talus combined with subchondral cysts.