不同窝沟处理方法 对窝沟封闭剂渗透程度和边缘微渗漏影响的体外研究

目的 体外比较不同的窝沟处理方法 对窝沟封闭剂效果的影响。方法 50颗离体人类恒磨牙被随机分为5组,每组10颗。组1:低速杯状刷清洁并酸蚀(杯状刷组);组2:高速1/4球钻行窝沟釉质成形术并酸蚀(EST-Ⅰ);组3:高速极细金刚砂车针行窝沟釉质成形术并酸蚀(EST-Ⅱ);组4:激光清洁并酸蚀(激光组);组5:超声清洁并酸蚀(超声组)。窝沟封闭后,对封闭剂的渗透率及窝沟染料微渗漏进行测定。结果 激光组封闭剂渗透率最低与低速杯状刷组、1/4球钻组及金刚砂车针组之间均有显著性差异(α<0.05)。激光组所有样本均出现染料渗漏,其微渗漏最严重,与其他4组均有显著性差异(α<0.05),1/4球钻组微渗漏发生最少,与金刚砂车针组、激光组以及超声组有显著性差异(α<0.05)。结论 应用高速1/4球钻行窝沟釉质成形术并酸蚀后再进行窝沟封闭,具有较好的渗透性和边缘封闭性。?     

超声预备牙体表面的三维形貌分析

目的:了解超声制备牙体的表面三维形貌特征.方法:将纳入的10颗上颌前磨牙,按照临床烤瓷冠牙体预备要求及步骤,完成牙体初步预备,形成的浅凹形肩台,采用分半预备,牙体一半(对照侧)使用常规马尼车针制备肩台及抛光,另一半(超声处理侧)依次使用超声预备车针PM1/PM2/PM4制备肩台及抛光,完成肩台边缘线,使肩台均匀下移约0.5 mm.通过电镜及白光干涉仪观察、记录表面三维粗糙度、表面偏态,采用SPSS 13.0软件包对所得的各组数据进行独立样本t检验分析.结果:扫描电镜及白光干涉仪均观察到,对照组表面旋转器械的砂石磨削痕迹明显;与处理组相比,呈现更细密的波纹状,而处理组波纹痕迹的上表面被较平整的小平面覆盖;超声处理组与对照组相比,处理组表面粗糙度以及表面偏态均显著小于对照组(P=0.011,P=0.000).结论:超声预备的牙体表面形貌较常规旋转器械更平整、光滑.     

车针转速对GuttaFlow根管充填后微渗漏的影响

目的 研究桩道预备过程中不同车针转速对GuttaFlow根管充填后微渗漏的影响。方法 40颗人上颌前牙截冠后统一工作长度为16mm,根管预备后GuttaFlow充填根管。样本按桩道预备车针转速随机分为5组:A组(车针转速为400r/min)、B组(800r/min)、C组(7000r/min)、D组(14000r/min)、E组(对照组,不进行桩道预备)。1周后各组按设定转速进行桩道预备,保留根尖4mm充填物。液体转移法测量根管微渗漏。实验数值采用SPSS13.0统计学软件进行单因素方差分析。结果 A组微渗漏值最大(7.531±1.309)×10-3μl/(kPa·min),与E组间有统计学差别。A组和D组间有统计学差异。其余各组间无统计学差异。结论 桩道预备过程中车针转速对GuttaFlow根管充填后微渗漏产生影响,转速过低时(400r/min)增加充填根管的微渗漏,不推荐使用于临床。?     

超声肩台预备对全冠边缘密合性影响的随机对照研究

目的： 评价在牙体缺损患者中行全冠超声肩台预备后的临床修复效果。方法： 选择32例后牙牙体缺损行全冠修复的患者共计35个单位修复体，随机分为实验组和对照组，实验组常规全冠基牙预备后采用超声对肩台进行预备，对照组采用常规金刚砂车针按照颗粒度逐级预备抛光，2组均取模完成氧化锆全冠修复。比较2组全冠修复体基牙边缘完成线的形态、修复体边缘密合性及6个月后复诊检查全冠邻边缘着色情况。采用SPSS17.0软件包对2组的A级评价结果分别进行组间χ2检验。结果： 2组基牙边缘密合性差异无显著性（P>0.05）；边缘完成线的形态及6个月后复诊检查修复体邻边缘着色情况实验组显著优于对照组（P<0.05）。结论： 牙体缺损全冠修复行超声肩台预备更为合理，能有效减少全冠边缘粘结后着色的发生。     

根尖手术中超声骨刀对根尖切面粗糙度的影响

目的:比较超声骨刀、裂钻车针和金刚砂车针切除根尖后切面粗糙度的差异。方法:收集符合纳入标准的离体牙60个,随机分为3组(每组20个),分别使用超声骨刀、裂钻车针和金刚砂车针切除根尖3 mm,检测并记录切面粗糙度值Ra;体视显微镜下观察切面形态。结果:超声骨刀、裂钻车针和金刚砂车针3组的根尖切面粗糙度值Ra分别是(0.470±0.071)μm、(0.567±0.100)μm和(2.354±0.313)μm。超声骨刀组根尖切面最光滑,金刚砂车针组根尖切面最粗糙,结果存在显著性差异(P<0.01);而超声骨刀与裂钻车针组结果无统计学差异(P>0.05)。结论:与传统的裂钻和金刚砂车针相比,在根尖手术中使用超声骨刀进行根尖切除,根尖切面粗糙度较小,表面更加光滑。     

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。     

不同粒度车针牙体预备对基底冠适合性影响的研究

目的：比较不同粒度金刚砂车针预备的牙体对烤瓷修复体基底冠适合性的影响。方法：采用4种不同粒度车针对预备牙面进行打磨,根据最终使用车针型号的不同将离体牙试件分为4组,分别制取印模并制作基底冠。采用玻璃离子水门汀将基底冠粘固在牙体上,评价其微渗漏情况和适合性。结果：预备体表面采用车针打磨至不同水平的各组牙试件,经玻璃离子粘固后的微渗漏等级之间存在显著性差异（P〈0．05）,各组基底冠与牙体之间的粘固剂厚度也存在显著性差异（P〈0．01）。结论：随车针粒度的减小,牙预备体与镍铬合金基底冠之间的适合性逐渐提高。     

2种微动力系统应用于下颌低位阻生智齿拔除术的比较研究

目的:比较电动式颌面微动力系统和高速气动外科手机在下颌低位阻生智齿拔除术中的应用效果。方法:将133 例下颌低位阻生智齿随机分成2组,分别使用电动式颌面微动力系统和高速气动外科手机进行手术,比较2组间拔牙时间和术后肿胀、疼痛、张口受限、干槽症、神经损伤、邻牙损伤情况,结果采用SPSS19.0软件包进行统计学分析。结果:电动式颌面微动力组的手术时间明显少于高速气动外科手机组,术后肿胀、疼痛、张口受限程度明显小于高速气动外科手机组(P＜0.05),干槽症、神经损伤发生率低于高速气动外科手机组,但差异无统计学意义。 结论:应用电动式颌面微动力系统拔除下颌低位阻生智齿具有良好的临床效果。     

高速车针尖部形状与肩台形状制备

临床上常用高速车针即涡轮机车针 (用金刚砂制作 )制备烤瓷冠 ,烤瓷贴面 ,金属全冠基牙 ,基牙边缘可能有多种形式的肩台 ,它与金瓷冠边缘瓷崩 ,烤瓷牙颈缘黑线 ,烤瓷牙牙周炎有一定的关系。涡轮机车针的尖端形状对制备出的基牙肩台形状有否影响 ,与烤瓷冠边缘瓷崩等有何联系。这方面文章尚不多见。本文结合实验及临床资料进行分析。1　材料与方法1.1　选用正畸要求拔下的 ,完好无损的离体前磨牙共 12颗。根据 5位临床医生常用的 84枚ＭＡＮＩ(日本产 )车针 ,按其尖端的形状分有 3类 :柱型 (倒园台型 ) ,圆锥型和尖型 (见图 1)。车针的颈部通…     

Er：YAG激光切除牙根断面的扫描电镜观察

目的对Er：YAG激光切除的牙根断面进行扫描电镜研究,并通过对比超声金刚砂尖以及高速涡轮金刚砂车针切除牙根断面的不同表面状态,为Er：YAG激光应用于临床根尖切除术提供依据。方法将30颗上颌中切牙随机分为3组（Er：YAG激光切除组、超声金刚砂尖切除组、高速涡轮金刚砂车针切除组）,分别使用Er：YAG激光、超声金刚砂尖以及高速涡轮金刚砂车针在距离根尖3 mm处进行牙根切除。使用扫描电镜观察3组牙根断面残屑及玷污层、牙本质小管开放、裂隙以及器械切割痕迹情况。结果Er：YAG激光切除组和超声金刚砂尖切除组牙根断面有少量残屑、玷污层,并有牙本质小管开放;高速涡轮金刚砂车针切除组牙根断面有大量残屑及玷污层,没有牙本质小管开放。高速涡轮金刚砂车针切除组中能看到大量裂隙出现,超声金刚砂尖切除组中可见裂隙出现,而Er:YAG激光切除组中几乎没有裂隙出现。高速涡轮金刚砂车针切除组和超声金刚砂尖切除组牙根断面的表面粗糙并有明显切割痕迹,而Er：YAG激光切除组牙根表面没有切割痕迹,较为平滑。结论Er：YAG激光应用于根尖切除具有一定的优势,其牙根断面组织形态学方面的表现明显优于超声金刚砂尖和高速涡轮金刚砂车针。     

Consistency of labial finish line preparation for metal ceramic crowns: an investigation of a new bur.

PURPOSE: Previous studies have reported on the difficulties inherent in preparing the labial aspect of teeth for metal ceramic crowns with consistency and also the implications for the definitive restoration of underprepared and overangled finish lines. In this study, a bur designed to prepare a 1.2-mm deep chamfer was tested and compared with two other bur kits. MATERIALS AND METHODS: Seventy-two teeth were prepared to receive metal ceramic crowns in vitro by students using one of the two bur kits or the new bur. Using a coordinate measuring machine (CMM), replicas of the prepared teeth were scanned in the mid-labial plane, and shoulder width and cavosurface angles were measured. RESULTS: The new bur produced preparations with a mean shoulder width and cavosurface angle of 1.146 +/- 0.241 mm and 108 +/- 11 degrees, respectively, compared with 0.626 +/- 0.234 mm and 128 +/- 14 degrees produced by a commercially available standardized crown cutting bur system and 0.626 +/- 0.218 mm and 124 +/- 15 degrees produced by the bur kit in use at our center at the time of the study. These differences were statistically significant at the 5% level, using Tukey's comparison of means. CONCLUSIONS: Teeth prepared by the new bur had wider shoulders and lower cavosurface angles than teeth prepared either with a standardized crown cutting system or locally selected bur kit. The quality of labial preparations produced by the new bur in terms of closeness to the postulated "ideal" width and angulation warrants further investigation.     

不同方法取出根管内塑化物的临床观察

目的:比较G钻、Hero642机用镍钛锉及显微超声技术三种方法取出根管内塑化物的效果。方法:结合手用根管锉,分别采用三种方法对186个根管进行再通畅治疗,通过X线、根尖定位仪对取出根管内塑化物的效果进行评价。结果:G钻组完全再通41个,Hero642镍钛组完全再通34个,显微超声组44个。结论:显微超声技术在三种塑化根管再通畅治疗中有较好的疗效,G钻在临床使用过程中较为方便。     

Physical dimensions and torsional properties of rotary endodontic instruments. 1. Gates Glidden drills

A laboratory study was performed on Gates Glidden drills to determine their physical dimensions and torsional properties. Five samples of sizes #1 to #6 drills from two brands distributed in the United States were measured for physical dimensions. Five samples of the most commonly used sizes #1, #2, and #3 drills from these two brands were tested at failure in both the clockwise and counterclockwise directions using an analog torque meter. The values for the bur head dimensions of both brands correspond closely to those established by the ISO. The mean values for torque at failure for both the clockwise and counterclockwise directions showed no statistically significant difference for each brand-size combination. However, some instrument groups had separation or fracture sites near the bur head, while other groups underwent failure near the hand-piece end. This study is the first part of a continuing investigation to establish standards for rotary endodontic instruments.     

两种拆除根管桩的方法比较

目的：比较超声与机用钻针在拆除根管桩中的作用。方法：选取人上颌中切牙30颗，截去牙冠后根管预备并采用铸造桩修复，使用磷酸锌水门汀粘固。30颗牙随机分为三组，10颗牙不作处理作为对照：10颗牙使用机用钻针在桩周围切割出4mm深的一圈窄沟；另10颗牙超声震动处理10分钟。使用AGS-10kNG万能电子力学试验机检测使桩脱位所需的载荷大小，应用SPSS对数据进行方差分析。结果：机用钻针和超声震动均可有效地减小铸造桩的固位力。结论：机用钻针和超声震动的方法均能有效地使桩脱位。     

The quality of ultrasonic root-end preparation: a quantitative study

Ultrasonic root-end preparation techniques have recently been introduced and revolutionized the field of endodontic surgery. The purpose of this study was to compare quantitatively the quality of root-end preparation techniques prepared by a specially designed ultrasonic retrotip with those prepared in a traditional manner by a microhandpiece bur. Twenty roots with two canals and an isthmus from extracted maxillary human molars were selected for this study. After instrumentation, obturation, and root-end resection, root-end preparations were made using either an ultrasonic retrotip or a conventional microhandpiece bur. With the aid of the image processing and analysis system, the specimens were inspected under a stereomicroscope for further evaluation of the quality of the shape and size of preparation. The results of this investigation showed that the ultrasonic root-end preparations produced more conservative and less perforated cavities than those made with conventional microhandpiece bur preparations.     

Apical microleakage of root-end cavities prepared by CO2 laser

This in vitro study in extracted human teeth was designed to compare the degree of dye penetration of root-end cavities prepared by CO2 laser, ultrasonic retrotip, or rotary instrument. Eighty-two human anterior teeth were prepared and obturated with laterally condensed gutta-percha and sealer. Root-end resection was performed at 90 degrees, 3 mm from apex. Root-end cavities were prepared by CO2 laser beam, ultrasonic retrotips, or bur and were filled with amalgam. The teeth were isolated and immersed in basic fuchsin at 36 degrees C for 48 hours. The roots were split longitudinally and examined by a stereomicroscope. Leakage was quantified by linear measurement of dye penetration with the aid of image-analyzing software. Apical leakage in the CO2 laser group was significantly less than in the ultrasonic retrotip and bur groups. The difference between the ultrasonic and bur groups was insignificant. Based on the results of this in vitro study, application of CO2 laser for root-end cavity preparation appears to decrease the apical leakage.     

Micromorphometrical analysis of conventional osteotomy techniques and ultrasonic osteotomy at the rabbit skull

Objectives: The ultrasonic osteotome, which was recently introduced, is an alternative to conventional methods of osteotomy. The aim of the present study was to establish the differences between three osteotomy techniques and to perform a quantitative roughness analysis of the osteotomized bone surfaces. Materials and methods: Fresh bony samples of standardized size were taken from the rabbit skull. The techniques used were as follows: reciprocate micro‐saw, Lindemann bur, ultrasonic osteotome with the two insert tips OT6 (rough) and OT7 (fine). The prepared surfaces were examined by light microscopy, environmental surface electron microscopy (ESEM) and by confocal laser scanning microscopy (CLSM). Results: It was difficult to distinguish between cortical and cancellous bone after using the conventional osteotomy technique. The ultrasonic technique preserved the original structure of the bone. The values observed for superficial roughness were as follows: 3.97 μm (micro‐saw), 5.7 μm (Lindemann bur), 2.48 μm (OT7) and 3 μm (OT6). There were statistical differences between the values of the bur and insert tip OT6 (P=0.015) as well as between the bur and insert tip OT7 (P=0.003). Conclusions: In the present study micromorphological differences after using various osteotomy techniques could be clearly identified.     

树脂直接修复后边缘密合性的影响因素分析

目的 探讨树脂直接修复洞型边缘密合性的影响因素,为临床操作提供指导。方法 取新鲜离体磨牙40颗（N₁=40）,制备近中面（或远中面）长方形窝洞后随机分为8组（n₁=5）,采用正交实验评价边缘精修方法（A）、粘接剂（B）和复合树脂（C）对微渗漏的影响。另取新鲜离体上中切牙10颗（N₂=10）,随机分为MT、KS两组（n₂=5）,MT组MANI TF-12EF车针处理釉质表面,KS组KaVo SONICflex气动超声工作尖处理釉质表面,用于粗糙度检测。结果 影响微渗漏的因素主次关系为：复合树脂>粘接剂>边缘精修方法。最优组合为A：气动超声工作尖精修釉质边缘,B：ENA bond SE粘接剂,C：ENA HRi复合树脂。KS组表面粗糙度显著小于MT组（P < 0.001）。结论 边缘精修方法、粘接剂和复合树脂是影响树脂直接修复洞型后边缘密合性的因素。     

Prospective study of two retrograde endodontic apical preparations with and without the use of CO2 laser

Abstract— This article covers a 4-year study that reports 320 cases in which endodontic surgery was performed for residual apical lesions or lesions that could not be treated in a conventional way. Four groups of 80 teeth each were formed and they were followed up after a 12-month interval. The first group comprised cases treated with a micro bur, retrograde filling and IRM; the second, cases treated at the apical and radicular portions with a CO₂ laser; the third, cases in which the retrograde cavity was prepared with an ultrasonic device instead of a micro bur; and the fourth group comprised cases treated in a similar way to the second group, i.e., cases treated at the apical and radicular portions, but with a CO₂ laser instead of a micro bur. After 12 months, the results showed a better prognosis with ultrasonic treatment. Regardless of technique, the CO₂ laser did not improve the healing process.     

Enamel loss at bond-up, debond and clean-up following the use of a conventional light-cured composite and a resin-modified glass polyalkenoate cement

The aim of this study was to determine whether there was any difference in the degree of enamel loss at bond-up, debond and enamel clean-up when two different adhesive systems were tested and with four different methods of enamel clean-up. The adhesive systems were 37 per cent o-phosphoric acid with Transbond XT (group 1) and 10 per cent poly(acrylic acid) conditioner with Fuji Ortho LC (group 2). Using flattened enamel specimens, enamel loss at each stage was determined using a planer surfometer. These stages were: prior to treatment, at pumice prophylaxis, following enamel etching or conditioning and following enamel clean-up. The four clean-up methods were a high-speed tungsten carbide bur, a slow-speed tungsten carbide bur, an ultrasonic scaler and debanding pliers.The results, analysed using non-parametric tests, demonstrated that significantly more enamel loss occurred following the use of 37 per cent o-phosphoric acid than poly(acrylic acid) conditioner (P = 0.001). At debond and prior to clean-up, more adhesive remained on the enamel surface in group 1 than in group 2 (P = 0.005). During the subsequent enamel clean-up and with both adhesive systems, the least enamel loss occurred following the use of the slow-speed tungsten carbide bur and the greatest loss was seen with the ultrasonic scaler or high-speed tungsten carbide bur.Overall, the lowest enamel loss was observed with the poly(acrylic acid) conditioner and Fuji Ortho LC system (group 2) and where enamel clean-up was performed using the slow-speed tungsten carbide bur.