不同灭菌法对齿科高速裂钻腐蚀的初步研究

目的研究齿科常用的灭菌方法：干热灭菌法、湿热灭菌法、化学浸泡灭菌法对高速裂钻腐蚀的影响。方法将100根全新高速裂钻随机分为10组,每组10根。第1组为对照组,不予以任何处理;另9组为实验组,分别用湿热灭菌法、干热灭菌法、化学浸泡法处理5、10、15次。采用称重法、扫描电镜观察及成分分析、表面显微硬度测量法对高速裂钻的腐蚀情况进行研究。结果湿热法处理5、10、15次组,干热法处理10、15次组以及化学浸泡法处理15次组与对照组相比,其重量增加均有统计学意义（ P<0.05）。电镜图片显示：湿热组形貌改变最为显著,出现明显腐蚀外观并与灭菌次数呈正相关;干热组最轻微。表面成分分析显示高速裂钻中的主要成分钨、铬、铁、钴、镍在灭菌处理前后其相对体积分数有所改变,其中钨以对照组、干热组、化学浸泡组、湿热组顺序依次增多;铁则以此顺序依次降低。与对照组相比,三种灭菌法均降低裂钻表面硬度（ P<0.05）,其中湿热组影响最大;干热组和化学浸泡组次之。随着灭菌次数的增加,湿热组和化学浸泡组裂钻表面硬度差异具有统计学意义（ P<0.05）,干热组硬度差异无统计学意义（ P>0.05）。结论不同灭菌处理对高速裂钻均产生一定的腐蚀,以湿热法最为明显。温度和湿度对高速裂钻的腐蚀有协同作用,干热灭菌对裂钻的腐蚀作用较轻。     

不同灭菌法对齿科高速裂钻力学性能的影响

目的研究齿科常用的3种灭菌方法（干热法、湿热法、化学浸泡法）对牙科高速裂钻力学性能的影响。方法将200根全新的钨钢高速裂钻随机分为10组。分别通过弯曲实验和扭转实验观察高速裂钻在不同灭菌方法处理后弯曲强度、弹性模量和扭转强度等力学指标的改变。结果干热灭菌法、化学浸泡法和湿热灭菌法对裂钻的力学性能均有影响,随着灭菌次数的增加,裂钻的弯曲强度、弹性模量和扭转强度均相应减弱。3种灭菌方法比较发现,湿热处理引起裂钻的力学性能降低最明显,而化学浸泡和干热处理引起的变化相似,且较小。结论不同灭菌方法对高速裂钻产生一定的作用,影响大小排列依次为：湿热法、化学浸泡法、干热法。鉴于干热灭菌腐蚀作用最弱,建议齿科常用的小型器械可使用干热灭菌法进行灭菌。     

金刚砂车针清洗消毒及灭菌方法的研究现状

金刚砂车针因其结构复杂、直接与患者口腔接触及需要重复使用的特点,因此关于该车针的清洗消毒灭菌方法一直受到人们的关注。常用的金刚砂车针清洗、消毒、灭菌的方法主要有人工清洗法、酶清洗法、超声震荡法、化学液浸泡法、干热灭菌法和湿热灭菌法。上述方法均存在优点和不足,本文综述了上述方法的适用范围和优缺点以及最新的研究进展。     

根管切削器械安全使用的探讨

目的探讨防止根管切削器械损耗的处理。方法抽取200枚后牙根管切削器械分成2组,将粘贴纸贴于器械柄部以记录使用的次数,分别进行干热灭菌和高压蒸汽灭菌,观察根管切削器械的形态。结果根管切削器械干热灭菌法与高压蒸汽灭菌法损耗率χ2检验P<0.05,有显著性差异。结论高压蒸汽灭菌效果优于干热灭菌法,建议根管切削器械处理使用高压蒸汽灭菌法。另外根据根管切削器械随着使用次数的增多,其损耗的机会相应增大,故通过粘贴纸记数方法,可杜绝根管切削器械无限制使用,从而使根管切削器械折断意外降到最低。     

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。     

3种方法用于三用枪消毒的效果比较

目的比较3种方法用于三用枪消毒的效果。方法采用现场采样检测方法,对用消毒剂表面擦拭消毒、2%碱性戊二醛浸泡消毒和高温高压蒸气灭菌法灭菌效果进行观察。结果使用消毒剂表面擦拭消毒法,三用枪细菌总数超标率为9.09%;使用戊二醛浸泡消毒和高温高压灭菌法消毒,三用枪全部无菌生长。结论消毒剂表面擦拭法的消毒效果较差;高温高压蒸汽灭法消毒临床应用最为方便,效果最好。     

不同浓度的过氧化氢对银汞合金表面性能的影响

目的研究不同浓度过氧化氢对银汞合金表面性能的影响。方法采用表面轮廓仪和扫描电镜对0 wt%、3.6 wt%、10 wt%和30 wt%四种浓度过氧化氢浸泡112 h后的牙科银汞合金的表面粗糙度、表面形貌进行比较,并运用光电子能谱仪分析0%和30%两种浓度过氧化氢浸泡后银汞合金的表面腐蚀产物。结果过氧化氢浸泡112 h后,不同银汞合金表面粗糙度的Ra和Rz的大小顺序均为0 wt%<3.6 wt%<10 wt%<30 wt%;且表面均有不同程度的腐蚀,主要表现为分布不均匀、孔径大小不一的点蚀,其中以30wt%过氧化氢浸泡组的腐蚀最明显;此外,0 wt%和30 wt%过氧化氢浸泡后,银汞合金表面分别检测到Cu、Sn、Hg、Ag、O元素,表面氧化物主要为SnO₂,与0 wt%过氧化氢相比,30 wt%过氧化氢浸泡后,银汞合金表面Ag、Hg、O元素含量明显下降,而Sn、Cu元素含量则升高。结论随着过氧化氢浓度的升高,银汞合金表面粗糙度增加,表面形貌有不同程度腐蚀,表面腐蚀产物成分有所改变,氧化程度减弱。     

5种抛光方法对钴铬烤瓷合金抗腐蚀性能的影响

目的 研究5种抛光方法对钴铬烤瓷合金抗腐蚀性能的影响.方法 制作30个钴铬烤瓷合金试样,随机分为5组,分别采用砂纸、金相布轮、橡皮轮、电解和化学方法进行抛光,测量试样的表面粗糙度.用浸泡实验检测试件在腐蚀液中浸泡后Co、Cr离子的析出量,并用扫描电镜观察试样浸泡前后的表面形貌.结果 电解抛光会破坏钴铬烤瓷合金试样,终止后续浸泡实验;化学抛光组表面粗糙度最大,为(0.35 ±0.09) μm,与其他组差异有统计学意义(P＜0.05).腐蚀液浸泡7d后,金相布轮抛光组试件Cr析出量最小,为(0.47 ±0.17) μg/cm2;化学抛光组试件Cr析出量最最多,为(2.34 ±0.76) μg/cm2,差异有统计学意义(P＜0.05).扫描电镜观察腐蚀液浸泡前的试件,金相布轮抛光和橡皮轮抛光可获得光滑表面,砂纸抛光和化学抛光后表面划痕明显;腐蚀液浸泡后各组表面划痕没有显著变化.结论 钴铬烤瓷合金采用金相布轮和橡皮轮抛光可获得较好的表面形貌和抗腐蚀性能,化学抛光对钴铬烤瓷合金表面形貌改善不大,其抗腐蚀性能最差.     

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目的应用扫描电镜观察传统高速牙钻法、空气喷砂法、CarisolvTM化学机械法去龋后牙本质表面玷污层,肉眼观察窝洞洞底表面。方法将2006年3月至2006年6月南昌大学附属口腔医院收集的新近拔除伴中度龋坏的15颗患牙,依据去龋方法的不同分为3组:传统高速牙钻组、空气喷砂组和CarisolvTM化学机械组。去龋后肉眼观察窝洞洞底表面,并用扫描电镜对牙本质表面玷污层进行观察。结果3种方法均可有效去龋。传统高速牙钻组去龋后窝洞洞底牙本质表面平整、光亮而且透明;空气喷砂组牙本质表面粗糙、凹凸不平;CarisolvTM化学机械组牙本质表面光泽较暗。扫描电镜下观察,CarisolvTM化学机械组去龋后牙本质小管附近玷污层少,牙本质小管栓塞率仅为4.4%,明显低于其他2组(P均<0.05);空气喷砂组牙本质小管清晰可见,周围玷污层仅有少量分布;传统高速牙钻组牙本质小管清晰度较差,周围玷污层大量分布,牙本质小管栓塞率明显高于其他2组(P均<0.05)。结论CarisolvTM化学机械法能有效去龋,清除牙本质玷污层。     

2种方法在下颌水平阻生第三磨牙拔除中的比较

目的比较舌侧骨板劈开法与高速手机裂钻去骨法拔除下颌低位水平阻生第三磨牙的效果。方法将150颗下颌低位水平阻生第三磨牙随机分成2组, 每组75颗,分别采用舌侧骨板劈开法和高速手机裂钻去骨法拔除,记录手术时间及并发症情况并进行统计学分析。结果舌侧骨板劈开法和高速手机裂钻去骨法拔除下颌阻生第三磨牙的手术时间分别为（35.85±6.05）min和（43.52±7.70）min（P<0.05）。2种手术方法在骨折片去除、面部肿胀方面有统计学差异（P<0.05）,在牙龈撕裂、术后疼痛、张口受限、术后出血方面无统计学差异（P>0.05）。2种手术方法术后均未出现舌神经损伤及下唇麻木,高速手机裂钻去骨法发生干槽症1例。结论采用舌侧骨板劈开法拔除下颌低位水平阻生第三磨牙的手术时间短,且术中、术后并发症较少。     

Cutting effectiveness of diamond instruments subjected to cyclic sterilization methods

The effect of repeated sterilization on the cutting effectiveness of one brand of rotary dental diamond cutting instruments was measured. Four groups of five diamond burs were sterilized by four methods: (1) sterilization with a chemical agent (Sporicidin); (2) steam under pressure (autoclave); (3) dry heat (Dri-Clave); or (4) chemical vapor (Chemiclave). Each group of diamond instruments made a timed cut in a ceramic block. This cut and all subsequent cuts were measured and were used to determine a baseline cutting effectiveness. Each group of diamond burs was then ultrasonically cleaned, sterilized, and another cut was made. At the end of 10 cycles there was no difference in cutting efficiency of the dental diamond instruments. However, there are differences in the cutting efficiency of individual diamond instruments. The SEM evaluation made prior to cutting and at the end of the 10 cycles of sterilization demonstrated that diamond wear was similar in all groups and that little diamond particle loss occurred in any group.     

Effect of sterilization on the strength and cutting efficiency of twist drills

Retentive-pin twist drills were subjected to four methods of sterilization and then examined to determine possible effects on resistance to fracture, cutting efficiency, and surface condition. Sterilization methods included steam autoclave, chemical vapor autoclave, dry heat, and immersion in glutaraldehyde. Although the steam and chemical vapor groups had lower mean fracture strengths after sterilization, there was no statistically significant difference among the groups. Only the steam autoclave group showed a statistically significant loss of cutting efficiency. Scanning electron microscopic evaluation revealed that only drills sterilized by steam autoclave showed changes in the surface condition or cutting edges.     

Effect of four anticorrosive dips on the cutting efficiency of dental carbide burs

Because tungsten-carbide dental burs corrode during sterilization in an autoclave, four anticorrosive dips were studied to determine their effect on the burs in maintaining cutting efficiency.     

Sterilization beneath rings on dental instruments.

This study determined the effectiveness of standard methods of instrument sterilization beneath instrument rings. Sets of three types of dental instruments were contaminated with known amounts of bacterial spores (Bacillus stearothermophilus or Bacillus subtilis). Instrument rings were placed over the contamination and the instruments processed through standard cycles in a steam autoclave, an unsaturated chemical vapor sterilizer, a standard dry heat sterilizer, an ethylene oxide gas sterilizer or a 2.0% alkaline glutaraldehyde solution. Controls consisted of spore-contaminated instruments without rings that were not processed through any sterilizing method and that were processed through each sterilizing method. All instruments and their associated rings were cultured for the presence of live spores. The results indicate that the reliability of sterilization beneath the instrument rings used is greatest if the ringed instruments are processed through a steam autoclave or an unsaturated chemical vapor sterilizer.     

Effects of sterilization procedures on the cutting efficiency of stainless steel and carbon steel Gates Glidden drills

One-hundred fifty carbon steel Gates Glidden drills were compared with 150 stainless steel Gates Glidden drills before and after sterilization in an autoclave, salt beads, dry heat, or 2% alkaline glutaraldehyde. Cutting efficiency and separation rates of the drills were evaluated. Stainless steel #1 and 2 Gates Glidden drills resisted separation and maintained their cutting efficiency statistically better than the carbon steel #1 and 2 Gates Glidden drills after one sterilization cycle in an autoclave, salt bead sterilizer, or dry heat oven. Glutaraldehyde did not effect either type of drill.     

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。     

Effect of three sterilization techniques on finger pluggers.

The effects of different sterilization methods on the fatigue life of finger pluggers were investigated. Ninety finger pluggers for each of four sizes (A, B, C, and D) were subdivided into subgroups of 10. Each subgroup was subjected to 1, 8, or 15 cycles of steam autoclave, dry heat, or bead sterilization. Ten control pluggers for each size were not sterilized. After sterilization, experimental and control finger pluggers were subjected to cyclic bending until fracture. Only the A finger pluggers autoclaved for eight cycles had a significantly lower number of cycles to failure compared with that of the controls. Nine subgroups had significantly greater number of cycles before failure than did the control. Because all but one sterilized group had fatigue lifetimes statistically equal to or greater than nonsterilized controls, clinicians generally can use any of the three sterilization methods without fear of plugger failure.     

Glass bead sterilization of orthodontic bands

The purpose of this study was threefold: to determine if bead sterilization is capable of sterilizing orthodontic bands, if so, to establish a minimal time for sterilization when bands are inoculated with bacteria and spores, and to compare bead sterilization to other methods of cleansing and disinfecting orthodontic bands used in the office setting. Ten bands per time trial inoculated with either Bacillus subtilis spores or Staphylococcus albus bacteria were used along with ten controls (inoculated but not placed in the bead sterilizer). The bands were placed one at a time into a 226 degrees C bead sterilizer for 15, 30, 45, and 60 seconds, transferred to a test tube with BHI broth, and incubated at 37 degrees C for 3 days. The results indicated that 15 seconds is required to sterilize bacteria and 45 seconds required for spores. If five bands were placed in the bead sterilizer simultaneously, twice the time was required for sterilization. Other techniques for disinfecting bands, such as a 5-second tap water rinse, 10-second soap scrub, 30-minute immersion in alcohol, and alcohol flame, were ineffective in killing bacteria or spores with one exception--the alcohol flame was capable of preventing growth on bands inoculated with Staphylococcus albus.