An evaluation of the sealing ability of a polycaprolactone-based root canal filling material (Resilon) after retreatment.

OBJECTIVE: The aim of this study was to evaluate the sealing ability of Resilon after retreatment. STUDY DESIGN: Sixty-six single-rooted mandibular premolars were enlarged to apical size 45 and then obturated with Resilon. The roots were randomly divided into 3 groups (n = 22/group). In group 1 no further treatment was done. Groups 2 and 3 were reinstrumented to apical size 60 using K-files and ProFile, respectively. In each group, 4 samples were kept for environmental scanning electron microscopy (ESEM) analysis. The remaining roots from groups 2 and 3 were refilled with Resilon. Sixteen roots from each group were then evaluated for microleakage; two roots served as controls. Data were analyzed statistically by Kruskall-Wallis test. RESULTS: There were no significant differences between the experimental groups (P > .05). The ESEM showed new attachment of resin tags on the dentin surface of retreated roots. CONCLUSION: Resilon can be used for retreatment, but it still allowed microleakage.     

粘结型和非粘结型根管充填材料临床应用性能的比较研究

目的比较粘结型和非粘结型根充材料的根管封闭性和牙根抗折性能。方法收集成人离体下颌前磨牙115颗，按随机数字表分为6个实验组和3个对照组，分别用树脂胶Resilon-Epiphany体系（R1，R2）、牙胶-AHplus封闭剂体系（A1，A2）、牙胶-氧化锌封闭剂体系（z1，z2）及牙胶（c1，阳性对照组）进行热垂直加压充填，c2（阴性对照组）、C3（阴性对照组）不充填任何材料。葡萄糖微渗漏定量模型检测R1、A1、z1、c1、c2封闭性，压缩载荷破坏实验检测R2、A2、z2、c3牙根抗折性能。结果粘结型根充体系微渗漏最小[30d时葡萄糖浓度为（4．25±1．77）mmol／L]，非粘结型根充体系微渗漏最大[30d时葡萄糖浓度为（10．43±1．35）mmol／L]，各实验组间微渗漏值差异有统计学意义（P〈0．01）；各组牙根载荷值差异无统计学意义（P=0．7016）。结论全粘结根充体系能有效降低根管微渗漏，但对根充后牙根的抗折性能影响不大。     

Fascial space odontogenic infections: Ultrasonography as an alternative to magnetic resonance imaging

BACKGROUNDThe introduction of modern diagnostic tools has transformed the field of maxillofacial radiology. Odontogenic infection and fascial space involvement have been evaluated with many diagnostic tools, including ultrasonography (USG) and magnetic resonance imaging (MRI).AIMTo explore USG as an alternative model to MRI in the detection of fascial space spread of odontogenic infections.METHODSAmong 20 patients, 50 fascial spaces were clinically diagnosed with odontogenic infection and included in this prospective study. Fascial space infection involvement was examined by USG and MRI. Results were compared for both and confirmed by microbiological testing.RESULTSUltrasonography identified 42 (84%) of 50 involved fascial spaces. Whereas MRI identified all 50 (100%). USG could stage the infections from edematous change to cellulitis to complete abscess formation.CONCLUSIONMRI was superior in recognizing deep fascial space infections compared to USG. However, USG is a significant addition and has a definite role in prognosticating the stage of infection and exact anatomic location in superficial space infections.     

毛里求斯人和中国珠三角地区人上颌第一磨牙近中颊根根管形态比较研究

目的:了解毛里求斯人和中国珠三角地区人上颌第一磨牙近中颊根根管系统解剖特征.方法:收集并筛选毛里求斯人和中国珠三角地区人离体上颌第一磨牙各80颗.采用常规探查法、根管显微镜法和透明标本法分析MB2根管口定位规律,记录近中颊根的根管数目和根管类型.结果:毛里求斯人和中国珠三角人MB-MB2的距离分别为(1.74±0.95)mm和(1.33±0.77)mm,MB-P连线与MB2-P连线的夹角(α)为(6.37±1.32)°和(7.31±1.39)°毛里求斯人和中国珠三角人的多根管率分别是86.25%和82.50%.毛里求斯人的多根管以Ⅳ型为主,Ⅱ、Ⅱ、Ⅴ型次之,而中国人则以Ⅳ、Ⅱ型为主,Ⅲ、Ⅴ、Ⅵ型分别占少量.结论:人种不同上颌磨牙近颊根根管形态各有特点;辅助使用根管显微镜和超声工作尖,可提高上颌第一磨牙近中根管的多根管发现率,从而提高临床根管治疗成功率.