High-efficiency tooth bleaching using non-thermal atmospheric pressure plasma with low concentration of hydrogen peroxide

Light-activated tooth bleaching with a high hydrogen peroxide (HP; H₂O₂) concentration has risks and the actual role of the light source is doubtful. The use of conventional light might result in an increase in the temperature and cause thermal damage to the health of the tooth tissue.

Objective:

This study investigated the efficacy of tooth bleaching using non-thermal atmospheric pressure plasma (NAPP) with 15% carbamide peroxide (CP; CH₆N₂O₃) including 5.4% HP, as compared with conventional light sources.

Material and Methods:

Forty human teeth were randomly divided into four groups: Group I (CP+NAPP), Group II (CP+plasma arc lamp; PAC), Group III (CP+diode laser), and Group IV (CP alone). Color changes (ΔE ) of the tooth and tooth surface temperatures were measured. Data were evaluated by one-way analysis of variance (ANOVA) and post-hoc Tukey''s tests.

Results:

Group I showed the highest bleaching efficacy, with a ΔE value of 1.92-, 2.61 and 2.97-fold greater than those of Groups II, III and IV, respectively (P<0.05). The tooth surface temperature was maintained around 37ºC in Group I, but it reached 43ºC in Groups II and III.

Conclusions:

The NAPP has a greater capability for effective tooth bleaching than conventional light sources with a low concentration of HP without causing thermal damage. Tooth bleaching using NAPP can become a major technique for in-office bleaching in the near future.     

Is Pursuit of Termination of Atrial Fibrillation During Catheter Ablation of Great Value in Patients with Longstanding Persistent Atrial Fibrillation?

Termination of Atrial Fibrillation During Catheter Ablation Predicts Better Outcome . Background: The reliable endpoint for ablation of longstanding persistent atrial fibrillation (LPAF) has not been clearly established. Methods and Results: This study included 140 patients who underwent catheter ablation for drug‐refractory LPAF. A stepwise ablation approach included circumferential pulmonary vein isolation followed by left atrial and right atrial complex fractionated electrogram‐guided ablation. Atrial fibrillation (AF) was terminated by radiofrequency application during catheter ablation in 95 patients (67.9%). Among them, 33 patients (23.6%) converted to sinus rhythm directly, whereas 62 patients (44.3%) via atrial tachycardias (ATs). Patients in whom AF terminated during the index procedure had a lower recurrence rate of atrial arrhythmia than patients in whom AF did not terminate (45.3% vs 68.9%, P = 0.009, follow‐up 18.7 ± 7.6 months). Among patients in whom AF terminated, there was no significant difference in recurrence rate according to the termination mode, whether converted to AT or not (P = NS). However, patients who converted to AT had a higher recurrence rate of AT (54.8% vs 81%; P = 0.016). Multivariable logistic regression analysis demonstrated that termination of AF during ablation (HR 0.440; 95% CI: 0.200–0.969, P = 0.041) and structural heart disease (HR 2.633; 95% CI: 1.211–5.723; P = 0.015) were significant independent factors predicting the recurrence of atrial arrhythmia. Conclusions: Termination of AF during catheter ablation is associated with a better clinical outcome in patients with LPAF. (J Cardiovasc Electrophysiol, Vol. 23 pp. 1051‐1058, October 2012)     

Prediction of Long‐Term Outcomes of Catheter Ablation of Persistent Atrial Fibrillation by Parameters of Preablation DC Cardioversion

Prediction of Long‐Term Outcomes of Catheter Ablation of Persistent Atrial Fibrillation. Aim: It has been demonstrated that atrial fibrillation (AF) frequently recurred after cardioversion (CV) using direct current (DC) or radiofrequency catheter ablation (RFCA) in patients with persistent (PeAF) or longstanding persistent AF (LPAF). We hypothesized that the atrial substrate impeding successful CV would also produce difficulty in catheter ablation, and therefore, the outcomes of RFCA for PeAF and LPAF could be predicted by the parameters determined at the time of DC CV. Method: From 2006 to 2009, 94 patients with PeAF and LPAF who had undergone elective DC CV before RFCA were studied. The parameters associated with DC CV, including number of shocks, cumulative energy adjusted, highest energy adjusted, with or without intravenous amiodarone use, and other clinical parameters were assessed. Result: Thirty‐two out of the 94 patients (34%) experienced AF recurrence during the follow‐up of 19.8 ± 12.3 months after RFCA. The average time to recurrence of AF after RFCA was 9.2 ± 3.2 months. Of the 62 patients, 29 patients (31%) remained sinus rhythm (SR) without antiarrhythmic drug (AAD). The patients who maintained SR had smaller body mass index (BMI) (P = 0.048), shorter duration of AF (P = 0.012), and lower prevalence of diabetes mellitus (P = 0.023) compared with patients in whom AF recurred. Total number of shocks, total energy, and highest shock energy during CV were lower (P < 0.001, P = 0.002, P = 0.048, respectively) in patients with SR during the follow‐up. The outcome in patients who used amiodarone IV prior to CV, however, was not different from that in those who did not use amiodarone IV. Conclusion: DC energy parameters for successful CV before RFCA were useful to predict the long‐term outcome after RFCA in patients with PeAF and LPAF. The presence of the atrial substrate making DC CV difficult might reflect atrial substrate that subsequently related to the recurrence of AF after RFCA in chronic AF. These DC energy parameters may be related to the chronicity or electroanatomical remodeling of AF. (J Cardiovasc Electrophysiol, Vol. 23, pp. 1165–1170, November 2012)     

293.15 K时乙腈+水+［Hmim］Cl三元系统及其二元系统的折光率测定与关联

主要通过折光率来研究离子液体对乙腈+水系统物理性质的影响。采用折光仪测定了乙腈+水+［Hmim］Cl（1-己基-3-甲基咪唑氯盐）三元系统及相应的乙腈+水、水+［Hmim］Cl、乙腈+［Hmim］Cl二元系统在293.15 K时的折光率,并获得了这些系统的过量折光率,建立了折光率与组成间的经验关系。结果表明,在全部浓度范围内过量折光率均为正值,且乙腈+水的折光率随组成变化出现极大值,而水+［Hmim］Cl、乙腈+［Hmim］Cl的折光率均随离子液体组成的增加而增加。用RedlichKister、Cibulka模型和Singh模型分别关联了二元和三元系统的过量折光率,证实可采用Kohler方程估算三元系统的折光率。     

Comparison of desaturation and resaturation response times between transmission and reflectance pulse oximeters

Background: In general, there is a response time between actual arterial hypoxemia and its detection by pulse oximeters. We compared the desaturation and resaturation response times between two types of pulse oximeters, transmission and reflectance pulse oximeters, to find out which oximeter has a more rapid response time. Methods: Thirty‐three ASA 1 or 2 patients were enrolled in this study. A transmission pulse oximeter was placed on the index finger and a reflectance pulse oximeter was placed on the forehead and monitored simultaneously. After the induction of general anesthesia without pre‐oxygenation, we waited until the oxygen saturation value of any of two pulse oximeters declined to 90%, and then mask ventilation was started with 100% oxygen. Oxygen saturation was recorded at an interval of 2 s during this time. Results: The desaturation response time of SpO₂ to 95% after apnea was 82.0 s (interquartile range: 67.0–98.5 s) vs. 94.0 s (interquartile range: 84.0–106.5 s) (P<0.001) and SpO₂ to 90% was 94.0 s (interquartile range: 75.5–109.5 s) vs. 100.0 s (interquartile range: 84.5–114.5 s) (P<0.001) in the reflectance and transmission oximeters, respectively. The resaturation response time from mask ventilation to 100% SpO₂ was 23.2±5.6 vs. 28.9±7.6 s (P<0.001) in the reflectance and transmission oximeters, respectively. Conclusion: In clinical situations in which rapid changes in oxygen saturation are expected, we recommend the forehead reflectance pulse oximeter because it responds more quickly in detecting oxygen desaturation and resaturation compared with the transmission pulse oximeter.     

应用Micro CT颌骨骨小梁微细解剖学分析

目的 探讨高分辨率的MicroCT在骨形态三维结构的技术特长.方法 共10例下颌骨标本被分为髁状突组和下颌骨体部组,20个volumeofinterests被图像分析软件建立,每组各10个.计算每个像元大小的每个参数的平均值和标准差,并反复用ANOVA检验不同参数的值之间是否存在统计学意义（P ＜0.05）.结果 在所有重建像元大小中,下颌骨体部组的骨体积与骨体积分数与18μm像元组相比较有显著意义（P ＜0.05）.在髁状突组中,比36μm大的像元大小有意义（P ＜0.05）,但像元大小在36μm时并未发现显著差异（P ＞0.05）.骨小梁厚度及数量在下颌骨体部组和髁状突组都有显著意义（P ＜0.05）.结论 MicroCT是一种快速、准确、不损伤标本内部结构有效的评价方法.     

Transcatheter arterial chemoembolization vs. chemoinfusion for unresectable hepatocellular carcinoma in patients with major portal vein thrombosis

Background  Transcatheter arterial chemoembolization (TACE) has been limited in palliative treatment of unresectable hepatocellular carcinoma (HCC) with major portal vein (PV) invasion due to the possibility of liver failure following embolization. Transcatheter arterial chemoinfusion (TACI) has been an option in such cases.
Aim  To compare clinical outcomes after TACE vs. TACI in HCC patients with major PV occlusion.
Methods  We compared clinical outcomes after TACE vs. TACI in HCC patients with major PV occlusion. From 2005 to 2007, 110 HCC patients with major PV thrombosis were treated with TACE ( n  = 49) or TACI ( n  = 61).
Results  The morbidity rate was similar for both TACE (6.1%) and TACI (6.5%) patients, and complications were adequately managed using medical treatment. The Kaplan–Meier survival analysis showed that the survival period was significantly longer for the TACE group (median: 14.9 months) than for the TACI (median: 4.4 months) group ( P  < 0.001). There was a higher probability of death in the TACI group than in the TACE group in both our multivariate Cox-proportional hazards (OR 3.09, P  < 0.001) and the propensity score-matched (27 pairs) cohort analyses (OR 2.27, P  = 0.024).
Conclusions  Transcatheter arterial chemoembolization can be safely performed in HCC patients with main PV occlusion. Compared with TACI, TACE may result in longer survival of HCC patients with major PV occlusion.