Oral health‐related quality of life in patients with non‐metal clasp dentures: a randomised cross‐over trial

We investigated the efficacy of non‐metal clasp dentures (NMCDs) with regard to the oral health‐related quality of life (OHRQoL) and compare the findings with those for conventional metal clasp‐retained dentures (MCDs). This single‐centre, randomised controlled, two‐phase, open label, cross‐over trial included 28 partially dentate individuals. The patients were randomised to receive MCDs followed by NMCDs, or the opposite sequence (n = 14 in each group); each denture was worn for 3 months. OHRQoL was evaluated using the Oral Health Impact Profile‐Japanese version (OHIP‐J) at entry (T‐entry; before treatment with the first denture) and at 3 months after treatment with each denture (T3). An examiner evaluated denture stability, oral appearance and surface roughness before denture delivery (T0) and at T3 and denture hygiene at T3. A total of 24 patients completed the trial. There were no complications related to the dentures, abutment teeth or denture‐bearing mucosa during the follow‐up periods for both dentures. The mean OHIP summary score was lower for NMCDs than for MCDs, and the difference (9 points) was greater than the minimal important difference (6 points), indicating the difference was clinically relevant. The effect size was medium (0·70). Statistical analyses with linear mixed models found a significant effect of the denture type on the OHIP summary score and scores for the Oro‐facial appearance, Oro‐facial pain and Psychological impact domains (NMCD < MCD; P < 0·05). The results of our study suggest that NMCDs allow for better OHRQoL compared with MCDs.     

乳牙预成冠及树脂修复治疗乳磨牙大面积龋的临床效果观察

目的乳牙预成冠及树脂修复治疗乳磨牙大面积龋的临床效果观察。方法 2013年7月至2015年12月于本院就医的乳磨牙龋的患儿78例,所有患儿均通过入院前确诊,满足乳磨牙龋诊断标准,然后按照随机数字表法分为观察组与对照组,各组均为39例,其中观察组采用预成冠方法进行修复,而对照组以复合树脂进行修复,两组患儿均为同一位医生完成治疗,统计各组的总体治疗成功率。结果本研究半年内两组患儿随访临床治疗评估(每月1次)显示,观察组患儿在治疗后3个月、6个月的总有效率分别为97.43%、94.87%,均高于对照组的89.74%、84.61%,以上组间差异显著,具有统计学意义(P0.05);对于乳牙功能的行使保存,预成冠成功率要远远高于树脂修复成功率,预成冠保存乳牙继续行使咀嚼功能疗效较树脂修复显著,以上两组的组间数据对比存在明显差异,具有统计学意义(P0.05)。结论对于乳磨牙龋修复而言,运用预成冠修复方法无论在成功率、咀嚼功能疗效均高于树脂修复效果,具有临床推广意义。     

高纯度庆大霉素C1a游离碱制备工艺研究

目的 探索用大孔吸附树脂层析法及盐析结晶法精制纯化硫酸依替米星起始物料-庆大霉素C1a成品(HPLC纯度91%~93%)，从而减少由起始物料引入依替米星杂质的水平。方法 以庆大霉素C1a吸附量和庆大霉素C1a纯度为指标，考察大孔吸附树脂纯化庆大霉素C1a的吸附性能和洗脱参数；以盐析后庆大霉素C1a样品纯度和盐析收率为指标，考察盐析工艺最佳温度、溶剂、酸的添加量及酸的种类。结果 获得较优的树脂NM200，获得较优的解析液pH值为2.0和流速0.5BV/h。经过优化后，纯化收率从65%提高至74%。通过盐析结晶条件筛选和优化，确定室温先加溶剂后加硫酸(pH6.5)和甲醇与乙醇1:2的条件较优，优化后获得的庆大霉素C1a纯度达到98.2%，收率大于93%。研究了多种无机酸盐析结晶的情况，发现磷酸、硫酸和碳酸条件下能析出白色固体。结论 通过比较大孔吸附树脂和盐析结晶的纯化连接，组合纯化后获得的庆大霉素C1a游离碱纯度大于99.0%，比纯化前样品提高6%以上，收率大于70%。     

Ultrasonic measurement of the effects of light irradiation and presence of water on the polymerization of self‐adhesive resin cement

Self‐adhesive resin cements are useful in restorations because they reduce the number of clinical steps involved in the restoration process. This study evaluated, using ultrasonic measurements, the influence of light irradiation and the presence of water on the polymerization behavior and elastic modulus of a self‐adhesive resin cement. A self‐adhesive resin cement (RelyX Unicem 2 Automix) or a resin cement (RelyX ARC) was inserted into a transparent mold on a sample stage, and the presence of water and effect of light‐irradiation were evaluated. The transit time of a sonic wave through the cement disk was divided by the specimen thickness to obtain the sonic velocity, and longitudinal and shear waves were used to determine the elastic modulus. When the resin cements were light‐irradiated, the sonic velocity rapidly increased and plateaued at 2,500–2,700 m s^?1. When the cements were not irradiated, the rates of increase in the sonic velocity were reduced. When water was applied to the sample stage, the sonic velocity was reduced. The elastic modulus values of the specimens ranged from 9.9 to 15.9 GPa after 24 h. The polymerization behavior of self‐adhesive resin cements is affected by the polymerization mode and the presence of water.     

Evaluation of the effectiveness of bioactive glass fillers against Candida albicans adhesion to PMMA denture base materials: An in vitro study

BackgroundDentures with antimicrobial properties are desirable for preventing Candida albicans adhesion. This study was to assess the effectiveness of bioactive glass (BAG) on C. albicans adhesion, surface roughness, and hardness of denture base materials.MethodsHeat-polymerized (HP) and autopolymerized (AP) acrylic resins were used to fabricate 240 disk specimens (120/material, 60/C. albicans, 60/surface roughness and hardness). Specimens were divided into five groups (n = 10) based on the BAG concentration: 0.5, 1.5, 3, 5, and 7.5 wt% of the acrylic powder, with a control group comprised of unmodified specimens. Direct culture method was used to assess C. albicans adhesion. A profilometer and Vickers hardness test were used to measure surface roughness and hardness respectively. Analysis of variance (ANOVA) and post hoc Tukey’s test were used for data analysis (α = 0.05).ResultsBAG addition significantly decreased the C. albicans count when compared with the control group (P < 0.001) for both HP and AP. Regarding surface roughness, there was no change in the HP acrylic resins (P > 0.05), while the AP acrylic resins exhibited significantly higher surface roughness with BAG addition (P < 0.001). The hardness of the HP and AP acrylic resins were significantly higher with the addition of BAG (P < 0.001).ConclusionsThe addition of BAG to HP and AP acrylic resins effectively decreases C. albicans adhesion. The roughness of AP acrylic resins increases with the addition of BAG, while the hardness of both HP and AP acrylic resins increase with the addition of BAG.