Survival analysis of crown margin repair: A retrospective study in a dental school setting

BackgroundRepairing crowns with defective margins is minimally invasive and cost-effective compared with replacement. The authors’ objectives were to examine the survival trajectory of crown margin repairs and to determine the factors associated with survival.MethodsRecords of adult patients from January 2008 through August 2019 were reviewed for crown margin repairs completed at University of Iowa College of Dentistry. A total of 1,002 crown margin repairs were found. Each repair was followed through the end of study in 2019 or until an event (for example, additional repair, endodontic treatment, crown replacement, or extraction). A Cox proportional hazards model was used to study the relationship between selected covariates and time to event.ResultsDuring the follow-up period, 32.8% of the repairs needed reintervention. In the final model, repair material was the only significant covariate. No difference was found between the survival of repairs done with resin-modified glass ionomer and amalgam. However, the repairs done with resin-based composite and conventional glass ionomer were more likely (1.5 times: 95% CI, 1.02 to 2.10 times; and 2 times: 95% CI, 1.40 to 2.73 times, respectively) to need reintervention than were those done with amalgam.ConclusionsMedian survival time of crown margin repairs was 5.1 years (95% CI, 4.48 to 5.72 years). Median survival times for amalgam, resin-modified glass ionomer, resin-based composite, and glass ionomer repair materials were 5.7 years (95% CI, 4.80 to 6.25 years), 5.3 years (95% CI, 4.73 to 6.34 years), 3.2 years (95% CI, 2.51 to 6.19 years), and 3.0 years (95% CI, 2.53 to 3.62 years), respectively.Practical ImplicationsWhen considering crown margin repairs, resin-modified glass ionomer or amalgam is preferable to resin-based composite or glass ionomer.     

26所基层民营口腔诊所医务人员手卫生现况调查

 目的 调查十堰市区基层民营口腔诊所医务人员手卫生现况。方法 2019年9—11月采用便利抽样法对十堰市区民营口腔诊所医务人员手卫生现况进行隐蔽式调查,分析并比较不同岗位类别医务人员的手卫生依从率及正确率。结果 共调查民营口腔诊所26所,设有专用洗手设施的仅17所(占65.38%),配有快速手消毒剂的12所(46.15%)。隐蔽式观察102名医务人员,观察有效手卫生时机2 183次,医务人员实际执行572次,手卫生依从率26.20%,正确率25.52%(146次)。不同岗位类别医务人员的手卫生依从率、正确率比较,差异均有统计学意义(均P＜0.001)。护士的手卫生依从率(30.80%)、正确率(31.85%)较其他岗位人员高。医务人员在接触患者体液后的依从率(76.24%)和正确率(40.26%)较其他手卫生时刻高,接触患者前后的手卫生依从率最低,仅为15.38%、24.72%。医务人员不同手卫生时刻的依从率、正确率比较,差异均有统计学意义(均P＜0.001)。结论 基层民营口腔诊所医务人员手卫生依从率和正确率均较低,急需相关部门加强对基层民营口腔诊所的手卫生管理。     

Clinical application of automated virtual orbital reconstruction for orbital fracture management with patient-specific implants: A prospective comparative study

The aim of the study was to compare automated and manually conducted (slice-by-slice) virtual orbital wall reconstruction in terms of PSI design, manufacture, and clinical application for orbital fracture management.Patients with orbital wall fractures were evaluated for the potential for treatment with PSI, based on automated virtual wall reconstruction; these formed the main group. The surgical outcomes of these main-group patients' treatments were compared with those of the control group, which comprised patients randomly selected for this study, each of whom had the same orbital trauma patterns and were also managed with PSI. However, the control group patients were treated using ‘slice-by-slice’ virtual orbital reconstruction.Mean volume differences between the intact and reconstructed orbit were 0.65 ± 0.26 cm³ in the main group (n = 23) and 0.57 ± 0.23 cm³ in the control (n = 27; p = 0.837). In both groups, no cases of implant malposition or enophthalmos were detected after surgery. Orbital shape difference was similar for the main group and the control, at ?3.3 ± 3.5% and 3.25 ± 2.5%, respectively (p = 0.929). Diplopia was diagnosed at the 3-month follow-up in 13.0% of the main group and in 11.1% of the control (p = 0.651). The average times spent on computer-aided design (CAD) procedures, including segmentation, virtual orbital reconstruction, and PSI design, were 36.7 ± 6.9 min in the main group and 72.9 ± 7.7 min in the control group (p < 0.001).Within the limitations of the study it seems that PSI based on automated virtual reconstruction is a relevant alternative treatment option for orbital fractures because of its clinical efficacy that is similar to PSI based on a ‘slice-by-slice’ CAD protocol.     

应用锥形束CT对种植区牙槽骨质量分类方法的改良研究

目的    应用锥形束CT（cone beam CT，CBCT）测量种植区牙槽骨质量并结合Lekholm和Zarb分类法对骨质量分类方法进行改良，以期为提高牙槽骨质量分类的准确性提供指导。方法    选择2015年10月至2017年10月在呼和浩特市口腔医院种植科进行种植修复的196例患者术前CBCT影像资料，应用 Invivo5诊断设计软件测量306个种植位点的牙槽骨皮质骨厚度和松质骨密度（皮质骨与松质骨的CT值差值），以Lekholm和Zarb分类法为基础结合测量数据对骨质量进行改良后的量化分类。结果    牙槽骨皮质骨厚度为0.18 ~ 2.89 mm，中位数为0.92 mm。皮质骨与松质骨的CT值差值为88.5 ~ 667.8 HU，应用百分位数法找到33.3%和66.6%对应的数值分别为297.8 HU和356.1 HU。依据此数据结合Lekholm和Zarb分类法将196例患者的306个种植位点骨质量分为4类，其中Ⅰ类骨种植位点46个（占15.0%），Ⅱ类骨104个（占34.0%），Ⅲ类骨114个（占37.3%），Ⅳ类骨42个（占13.7%）。结论    结合Lekholm和Zarb分类法，应用CBCT测量种植区牙槽骨质量并进行分类方法的改良，可为临床医生术前评估牙槽骨质量提供一定参考。