黑龙江省逊克县火山熔岩地区啮齿动物携带病原体调查

目的 调查黑龙江省逊克县火山熔岩地区啮齿动物携带病原体状况.方法 2014年4-9月,采集啮齿动物样本107只,解剖取脏器肺、肾、肝、肾和膀胱样本,采用PCR方法分别扩增10种鼠传病原体的特异性核酸片段,通过基因测序进一步鉴定.结果 在107份鼠肺中共检出汉城型汉坦病毒RNA核酸阳性样本5份,感染率为4.67％;107份鼠肾中共检出钩端螺旋体DNA核酸阳性样本6份,感染率为5.61％;107份鼠脾中共检出巴尔通体DNA核酸阳性样本7份,感染率为6.54％,嗜吞噬细胞无形体4份,感染率为3.74％;107份鼠肝、鼠脾中鼠疫菌、巴贝西原虫、斑点热群立克次体、恙虫病立克次体、莫氏立克次体的DNA核酸检测结果均为阴性;107份鼠膀胱中伯氏疏螺旋体的DNA核酸检测结果为阴性;在鼠体内还存在复合感染情况,感染率为2.80％.结论 黑龙江省逊克县火山熔岩地区啮齿动物中存在汉坦病毒、钩端螺旋体、巴尔通体和嗜吞噬细胞无形体的感染.     

Sparkle lamp ingestion: a rare cause of death

A 51-year-old man was brought to the emergency department after he had drunk 200 mL of fluid from a decorative sparkle lamp. His calcium level was 4.99 mmol/L with a blood gas pH of 7.21. His calcium levels were corrected and his acidosis improved, but his stay in the intensive care department was complicated on day 10 by upper gastrointestinal hemorrhage because of caustic erosions in his stomach. Ten days after admission, he had an emergency right hemicolectomy during which residual luminescent particles were found to have eroded through his cecal mucosa. He eventually died 15 days after admission because of disseminated intravascular coagulopathy and refractory septic shock. This case demonstrates the potential for fatal toxicity associated with ingestion of a common household item.     

The use of CAD/CAM in dentistry

Computer-aided design (CAD) and computer-aided manufacturing (CAM) have become an increasingly popular part of dentistry over the past 25 years. The technology, which is used in both the dental laboratory and the dental office, can be applied to inlays, onlays, veneers, crowns, fixed partial dentures, implant abutments, and even full-mouth reconstruction. This article discusses the history of CAD/CAM in dentistry and gives an overview of how it works. It also provides information on the advantages and disadvantages, describes the main products available, discusses how to incorporate the new technology into your practice, and addresses future applications.     

不同全瓷材料修复不同程度变色前牙的效果对比

目的 比较不同全瓷材料对根管治疗后不同程度变色前牙的修复效果.方法 选择根管治疗后前牙变色患者83例(102颗牙),将患牙按牙体变色的程度不同分为轻度变色牙46颗、中度变色牙33颗、重度变色牙23颗.用IPSe-max铸瓷制作全瓷冠修复轻度变色牙18颗、中度变色牙9颗、重度变色牙3颗;用Vita In-ceram渗透氧化铝陶瓷制作全瓷冠修复轻度变色牙14颗、中度变色牙11颗、重度变色牙7颗;用Lava氧化锆陶瓷制作全瓷冠修复轻度变色牙14颗、中度变色牙13颗、重度变色牙13颗.通过Crystaleye比色仪分别对修复体和天然邻牙进行测色,计算总色差△E值,并对全瓷冠与天然邻牙的颜色匹配度进行牙冠颜色评分(CCS).结果 IPS e-max铸瓷修复的轻度变色牙、中度变色牙及重度变色牙,其△E值依次升高(P＜0.05),而另外2种材料的△E值在不同程度变色牙组中比较,差异均无统计学意义(P＞0.05).在轻、中度变色牙组中,3种材料CCS比较,差异均无统计学意义(P＞0.05);在重度变色牙组中,Vita In-ceram、Lava氧化锆材料的CCS优于IPS e-max铸瓷(P＜0.05).结论 IPS e-max铸瓷对中、重度变色牙的修复效果较差,而Vita In-ceram渗透氧化铝陶瓷和Lava氧化锆陶瓷对于轻、中、重度变色前牙均有较好的修复效果.     

Comparative fracture strength analysis of Lava and Digident CAD/CAM zirconia ceramic crowns

PURPOSE

All-ceramic crowns are subject to fracture during function. To minimize this common clinical complication, zirconium oxide has been used as the framework for all-ceramic crowns. The aim of this study was to compare the fracture strengths of two computer-aided design/computer-aided manufacturing (CAD/CAM) zirconia crown systems: Lava and Digident.

MATERIALS AND METHODS

Twenty Lava CAD/CAM zirconia crowns and twenty Digident CAD/CAM zirconia crowns were fabricated. A metal die was also duplicated from the original prepared tooth for fracture testing. A universal testing machine was used to determine the fracture strength of the crowns.

RESULTS

The mean fracture strengths were as follows: 54.9 ± 15.6 N for the Lava CAD/CAM zirconia crowns and 87.0 ± 16.0 N for the Digident CAD/CAM zirconia crowns. The difference between the mean fracture strengths of the Lava and Digident crowns was statistically significant (P<.001). Lava CAD/CAM zirconia crowns showed a complete fracture of both the veneering porcelain and the core whereas the Digident CAD/CAM zirconia crowns showed fracture only of the veneering porcelain.

CONCLUSION

The fracture strengths of CAD/CAM zirconia crowns differ depending on the compatibility of the core material and the veneering porcelain.     

Influence of porcelain veneering on the marginal fit of Digident and Lava CAD/CAM zirconia ceramic crowns

PURPOSE

Marginal fit is a very important factor considering the restoration''s long-term success. However, adding porcelain to copings can cause distortion and lead to an inadequate fit which exposes more luting material to the oral environment and causes secondary caries. The purpose of this study was to compare the marginal fit of 2 different all-ceramic crown systems before and after porcelain veneering. This study was also intended to verify the marginal fit of crowns originated from green machining of partially sintered blocks of zirconia (Lava CAD/CAM system) and that of crowns obtained through machining of fully sintered blocks of zirconia (Digident CAD/CAM system).

MATERIALS AND METHODS

20 crowns were made per each system and the marginal fit was evaluated through a light microscope with image processing (Accura 2000) at 50 points that were randomly selected. Each crown was measured twice: the first measurement was done after obtaining a 0.5 mm coping and the second measurement was done after porcelain veneering. The means and standard deviations were calculated and statistical inferences among the 2 groups were made using independent t-test and within the same group through paired t-test.

RESULTS

The means and standard deviations of the marginal fit were 61.52 ± 2.88 µm for the Digident CAD/CAM zirconia ceramic crowns before porcelain veneering and 83.15 ± 3.51 µm after porcelain veneering. Lava CAD/CAM zirconia ceramic crowns showed means and standard deviations of 62.22 ± 1.78 µm before porcelain veneering and 82.03 ± 1.85 µm after porcelain veneering. Both groups showed significant differences when analyzing the marginal gaps before and after porcelain veneering within each group. However, no significant differences were found when comparing the marginal gaps of each group before porcelain veneering and after porcelain veneering as well.

CONCLUSION

The 2 all-ceramic crown systems showed marginal gaps that were within a reported clinically acceptable range of marginal discrepancy.     

Characterisation of machinable structural polymers in restorative dentistry

Objectives

To characterise the mechanical properties of the machinable polymers Pekkton^® (Cendres-Meteaux, Biel/Bienne, Switzerland), Lava Ultimate^® (3MESPE, Seefeld, Germany), Vita Enamic^® (Ivoclar Vivadent, Schaan, Liechtenstein) and the ceramic IPS e.Max Press^® (Ivoclar Vivadent, Schaan, Liechtenstein). To determine the structural integrity of full coverage crowns fabricated from these materials.

Fatigue performance of adhesively cemented glass-, hybrid- and resin-ceramic materials for CAD/CAM monolithic restorations

Objective

To evaluate the fatigue failure load, number of cycles until failure, and survival probability of adhesively cemented materials with different microstructures (glass-, hybrid- and resin-ceramic) used to manufacture CAD/CAM monolithic restorations.