5种灭菌器对牙科手机性能的影响

目的 了解5种灭菌器对牙科手机机械性能的影响情况。方法 用5种灭菌器分别对4把牙科手机进行灭菌200次，每完成10次灭菌全过程检测一遍牙科手机的夹持力和转速。结果 经200次灭菌后20支牙科手机中，1支停转，另有8支转速下降，低于30万转／分钟，但高于16万转／分钟．可满足基本使用要求。灭菌时间最短的灭菌器只明显影响一支牙科手机的转速，其他灭菌器均明显影响两支牙科手机的转速。结论 灭菌时间短对牙科手机机械性能影响小，灭菌前应做好牙科手机的清洁和润滑，以减少机械性能损耗。     

五种灭菌器对牙科手机灭菌效果的研究

目的检测5种灭菌器对牙科手机的灭菌效果.方法用酶联免疫吸附(ELISA)法检测5种压力蒸汽灭菌器灭菌后的HBsAg人为污染的牙科手机,并对5种灭菌器灭菌后的临床污染的牙科手机进行无菌检测,同时用嗜热脂肪杆菌芽胞检测5种压力蒸汽灭菌器的灭菌效果.结果 5种灭菌器生物监测均合格,5种压力蒸汽灭菌器杀菌效果都可达100%,其中2种灭菌器灭菌的所有牙科手机HBsAg抗原性检测均为阴性,其他3种灭菌器灭菌的牙科手机各有1支HBsAg抗原性检测为阳性.结论压力蒸汽灭菌器效果可靠,乙肝病毒是否灭活,还需做其他检测.牙科手机应严格遵守灭菌保养流程,灭菌后应洁净存放.     

两种消毒方法对牙科手机灭菌效果的评价

目的 :比较含氯消毒剂浸泡法和环氧乙烷气体灭菌法对牙科手机的灭菌效果。方法 :利用枯草杆菌黑色变种芽孢和乙肝表面抗原阳性血清污染牙科手机 ,消毒后进行定量杀菌实验 ,用酶联免疫吸附实验 (ELISA)法检测HBsAg 结果 :牙科手机浸泡在有效氯含量为 30 0 0× 10 -6的消毒剂中 30分钟 ,细菌杀灭率及乙肝表面抗原的抗原灭活率均未达到 10 0 % ,而环氧乙烷灭菌法可达到 10 0 %。结论 :环氧乙烷灭菌牙科手机效果可靠。     

戊二醛对牙科手机灭菌效果的实验室评价

目的:探讨碱性戊二醛(Cidex)对人工污染牙科手机的灭菌效果.方法:将人工污染牙科手机分别浸泡在0.5%、1%和2%的碱性戊二醛消毒液中,作用不同时间后放入中和剂中和10分钟取出,将浸泡处理后的牙科手机放入洗脱液中洗脱震荡40秒,对洗脱液进行检测.结果:0.5%、1%碱性戊二醛(Cidex)浸泡处理污染牙科手机4小时及2%碱性戊二醛(Cidex)浸泡处理污染牙科手机2小时,HBsAg灭活率均为100%;2%碱性戊二醛浸泡污染牙科手机10小时,对牙科手机上污染的枯草杆菌黑色变种芽孢菌的平均杀灭率为99.99%;2%碱性戊二醛浸泡污染牙科手机10小时,对灭菌处理后牙科手机进行无菌检查,其中有9支无菌检查合格、1支检菌仍为阳性.结论:2%Cidex浸泡处理污染牙科手机可完全破坏HBsAg抗原性,用2%Cidex浸泡处理临床污染牙科手机可作为杜绝口腔科器械HBsAg医源性传播的主要措施之一.     

电动牙科手机与涡轮气动牙科手机在贴面预备后的对比研究

目的:使用高速涡轮牙科手机与不同转速下的电动高速牙科手机分别对离体牙进行牙体预备,分别比较其预备后的表面粗糙度、贴面修复后的微渗漏程度及抗折力。方法:选取新鲜拔除完整无龋坏的前磨牙60颗,按预备方式分为4组(n=15):涡轮气动牙科手机(A组)与200000 r/min(B组)、50000 r/min(C组)和20000 r/min(D组)的电动牙科手机对离体牙进行预备,预备后组内随机选取试件进行3组(n=5)检测：采用白光干涉仪测量表面粗糙度;用树脂水门汀粘接贴面后进行老化试验,在显微镜下观察贴面中线纵截面的微渗漏情况;以及应用电子万能试验机测量抗折力。结果:采用不同牙科手机及不同转速电动牙科手机进行牙体预备：直接观察预备体表面粗糙度,4组无显著性差异(P>0.05);贴面粘接后进行抗折力测试4组无显著性差异(P>0.05);老化循环后微渗漏深度四组间存在显著性差异(P<0.05)。结论:20万转速下的电动手机预备后的贴面平均微渗漏程度最小。而预备体表面粗糙度和贴面抗折力不受手机类型及转速的影响。     

口腔材料与器械

国产碳纤维桩的固位力实验；MTT法评价国产碳纤维桩材料的细胞毒性；五种牙本质粘接剂体外细胞毒性研究；环氧乙烷对牙科手机灭菌效果及机械性能影响的实验研究；不同材料根管桩剪切粘结强度的比较；树脂透明牙模型用于根管治疗操作训练的效果评价；反向沉淀法制备牙科纳米氧化锆粉体；口腔修复常用合金稳态电位的测定；三种金属处理剂对金属与复合树脂间剪切粘接强度影响的研究。[编者按]     

牙科医师体表和诊室环境的污染状况分析

目的 通过牙科医师治疗过程中,身体表面及诊室空气各处的细菌检测,了解牙体治疗和牙周治疗时对医师和空气的污染情况.方法 牙科医师进行牙体、牙周治疗时,将普通血培养基固定在其口罩、防护眼镜、胸前体表及固定在牙科治疗椅照明灯、牙科治疗椅旁屏风处,暴露1 min,实验室37℃培养24 h,各取10例,计算均值.诊室连续使用3.5 h后,将普通血培养基放置于牙科治疗椅水杯平台、牙科治疗椅后方2 m远的护士操作台表面,暴露5 min,实验室37℃培养24 h,隔日1次,共取10次,统计菌落均值,计算空气细菌菌落总数.结果 牙科医师身体表面不同部位及牙科治疗椅周边均被污染,污染最严重的是口罩,与防护眼镜的污染有显著性差异(P＜0.05);诊室使用后,空气污染明显.结论 在口腔治疗过程中,牙科医师和牙科治疗椅周边的污染均十分严重;诊室空气细菌菌落总数明显高于医院消毒卫生标准.医师应注重自身防护,诊室设备、空气应及时消毒、灭菌.     

两种清洗方式对污染牙科手机洗涤效果分析

目的比较2种清洗方式对污染牙科手机上标准微生物的清洗效果。方法分别用标准试验菌株枯草杆菌黑色变种芽孢和大肠杆菌的菌悬液污染牙科手机机头各23支;3支污染后直接放入洗脱液,取洗脱液作为清洗前对照;另外20支分别采取手工刷洗10支,超声波清洗10支,再分别放入洗脱液,收集清洗后的洗脱液,分别接种培养,计数存活的标准试验菌菌落数,计算清除率。结臬对人工污染枯草杆菌黑色变种芽孢和大肠杆菌的牙科手机,手工刷洗后2种细菌清除率分别为86．66％、88．82％;超声波清洗后2种细菌清除率分别为90．68％、93．56％,2种方法的清除率有非常显著性差异（P〈0．01）。结论对人工污染2种标准试验菌株的牙科手机,超声波清洗效果优于手工刷洗效果。     

B级脉动真空压力蒸汽台式灭菌器对牙科手机灭菌效果分析

目的探讨B级脉动真空压力蒸汽台式灭菌器对牙科手机的灭菌效果。方法分析牙科手机灭菌器的选择、灭菌处理流程及灭菌效果监测,并对监测结果及牙科手机有效的灭菌方法进行评价。结果四川大学华西口腔医院采用B级脉动真空压力蒸汽台式灭菌器对牙科手机进行灭菌处理,其化学监测、生物监测指标均符合要求,灭菌有效率100%;对灭菌后牙科手机进行需氧培养、厌氧培养、乙型肝炎标志物监测均为阴性。结论对牙科手机采用B级台式灭菌器脉动真空压力蒸汽灭菌是行之有效的方法。     

牙科手机高压消毒的效果研究

目的 检测牙科手机的高压消毒效果。方法 分为高压蒸气消毒和紫外线消毒2组,每组的4个手机分别接种含1×10~9/ml浓度的金黄色葡萄球菌和变形链球菌菌悬液,经高压蒸气和紫外线分别消毒后的0min、30min、1h、2h、12h和24h分别采样,作细菌培养,记录CFU。结果 在高压蒸气消毒组,各检测时段均未培养出实验菌,而紫外线消毒组的牙科手机在检测的各个时段均有实验菌生长。结论 高压蒸气消毒对牙科手机的消毒效果是肯定的。     

Autoclave sterilization of dental handpieces: A literature review

PurposeThe present review aimed to investigate autoclave sterilization of dental handpieces based on available studies.Study selectionThe sterilizing efficiency of dental handpieces with autoclave is mainly affected by the types of apparatus (N, B, and S), the packaging with sterilizing pouch, cleaning, and lubrication. These subjects were reviewed based on the in vitro experimental studies.ResultsDental handpieces can be sterilized, including inactivation of heat-resistant bacterial spores, with type B or type S sterilizers, regardless of the use of a sterilization pouch. In contrast, although type N autoclaves are capable of sterilization of general bacteria such as Streptococcus salivarius even in a sterilization pouch if instruments are washed beforehand, complete sterilization of the wrapped handpiece is not always achieved. Therefore, to achieve sterilization efficiency with type N autoclaves, processing without any packaging is recommended. As regards cleaning of handpiece, although contamination decreases with irrigation and wiping of handpieces, all reports concluded that these treatments alone do not achieve complete decontamination of reusable handpieces.ConclusionAlthough type B and type S autoclaves allow us to sterilize the dental handpieces, it is important to realize that complete sterilization of the handpiece is not always achieved by type N autoclave. Understanding autoclave processing of handpieces is essential for dental practice to deliver the safe dental care.     

Steam sterilization of air turbine dental handpieces

The efficacy of autoclaving high-speed dental handpieces was tested in two types of downward displacement steam sterilizers (instrument autoclaves), commonly used in the dentist's office. Eight series of experiments were performed with various sterilization schedules. Lubrication oils with or without antimicrobial agent were used in four of the series. Each handpiece was inoculated with 1 ml of a suspension containing equal amounts of saliva and spores of Bacillus stearothermophilus (approx. 10(6) spores/ml). Neither sterilization at 120-124 degrees C for 20 min nor at 134-136 degrees C for 10 min resulted in complete inactivation of the spores in series in which the instruments were tested without oil or with oil containing no antimicrobial agent. However, when the handpieces were lubricated with oil containing isopropanol and formaldehyde and the schedule 134-136 degrees C/10 min was used, no growth was observed. The results indicate that instrument autoclaves with built-in programs of 120-124 degrees C/20 min and 134-136 degrees C/10 min could have insufficient capacity to sterilize lubricated or unlubricated dental handpieces. The use of oils containing an antimicrobial agent can overcome this problem.     

Evaluation of sterilization of dental handpieces by heating in synthetic compressor lubricant

The Centers for Disease Control and Prevention and the American Dental Association guidelines recommend sterilization of dental handpieces after each use. Steam autoclaving is the most commonly used sterilization method. However, pressurized steam causes corrosion and partial combustion of the handpiece lubricant, leaving a sticky carbon residue on the turbine which must then be replaced after several usages. Replacement of autoclave-damaged dental handpieces represents a major expense for dentists that may be avoided through the use of less destructive sterilization techniques.     

The effectiveness of two sterilization methods when different precleaning techniques are employed

The effectiveness was investigated of methods for the preparation of dental handpieces prior to sterilization procedures utilizing ethylene oxide (ETO) gas. The handpieces were cleaned using either a forced-air purging unit (group 1) or by flushing with air and water from the dental unit (group 2). They were inoculated with either Bacillus subtilis or Streptococcus mutans. After exposure to either steam or ETO gas, the handpieces were flushed with saline and the viability of recovered bacteria assessed. No viable bacteria were recovered from group 1 handpieces treated with either ETO gas or steam. However, viable S. mutans were recovered from group 2 handpieces following exposure to ETO gas. Thus, the use of a high-pressure forced-air purging unit may be required for the reliable sterilization of dental handpieces by ETO gas, as viable S. mutans could be recovered from untreated handpieces exposed to ETO gas.     

Performance of high-speed dental handpieces subjected to simulated clinical use and sterilization.

BACKGROUND: The authors investigated the performance of nine commercially available high-speed air-turbine dental handpieces subjected to 1,000 simulated clinical uses and sterilizations. METHODS: Six new handpieces from each of nine different models were subjected to simulated clinical use with a custom-made handpiece wear tester and then autoclaved. Ten parameters related to clinical performance (longevity, power, turbine speed, fiberoptic transmission, eccentricity, noise, chuck performance, visibility angle, interocclusal clearance and water coolant spray pattern) were measured at baseline and after 250, 500, 750 and 1,000 use/sterilization cycles. RESULTS: Power, turbine speed, eccentricity and noise performance were statistically analyzed using one-way analysis of variance and Turkey post hoc pairwise comparison tests at the .05 significance level. At baseline, significant differences were found between models for all of these parameters. In general, from baseline to 1,000 cycles, the handpieces exhibited greater eccentricity and reduced fiberoptic performance. Longevity data analyzed by using Gehan's generalized Wilcoxon test for comparison of survival distributions (alpha = .05) revealed significant differences between the handpiece models. CONCLUSIONS: The results of this study indicate that no handpiece model is superior to the others in all parameters evaluated. All models evaluated can be expected to perform for at least 500 clinical use/sterilizations, or approximately one year, if properly maintained. CLINICAL IMPLICATIONS: Clinicians need to be able to identify handpieces that can withstand repeated heat sterilization without loss of performance or longevity. The results of this study will aid clinicians in selecting handpiece models that meet their needs.     

Dynamic measurement of the torque-speed characteristics of dental high speed air turbine handpieces*

The first requirement for adequate performance of an air turbine handpiece is sufficient power. Suppliers of such handpieces do not provide data on the power produced by their equipment. A method for determining the torque, speed and hence power during simulated operation is described. Forty-one new and used handpieces were tested. Maximum speeds up to 500 000 rpm, maximum torques up to 2.33 N.mm and maximum power up to 29.6 watt were observed. The maximum power was produced at between 49 and 79 per cent of the free-running speed. A relationship between maximum power and stall torque was noted. The maximum torque is at stall for ball-bearing units. The stall torque can be easily determined by a simple stall torque test which is described. Using this test, the performance of handpieces can be easily checked in the clinic. The one air-bearing handpiece tested performed in a manner similar to the others, except that stall occurred below 60 000 rpm.     

Comparison of the cutting efficiencies of electric motor and air turbine dental handpieces

As part of a larger comprehensive performance evaluation to determine whether electric motor handpieces are a suitable substitute for air turbine handpieces in a portable field dental treatment and operating system, the cutting efficiencies of electric motor and air turbine handpieces were compared. A device was made that applies an identical cutting force to a glass ceramic material for each handpiece tested. The laboratory results show that with equal amounts of applied force, the electric motor handpiece cuts a glass ceramic material significantly more efficiently (volume of material removed per second) than does the air turbine. In clinical trials, after minimal experience utilizing the electric motor, the majority of dentists felt that the electric motor cut tooth and amalgam more efficiently than did the air turbine.