Quality of root canal fillings using three gutta-percha obturation techniques

OBJECTIVES: The goal of this study was to compare the density of gutta-percha root fillings obturated with the following techniques: cold lateral (CL) compaction, ultrasonic lateral (UL) compaction, and warm vertical (WV) compaction. MATERIALS AND METHODS: Thirty-three extracted mandibular first molars, with two separate mesial canals in each, were selected. After instrumentation, the canals were stratified into three groups based on canal length and curvature, and underwent obturation with one of the techniques. No sealer was used in order to avoid masking any voids. The teeth were imaged pre- and post-obturation using micro-computed tomography. The reconstructed three-dimensional images were analyzed volumetrically to determine the amount of gutta-percha present in every 2 mm segment of the canal. P values < 0.05 were considered to indicate statistical significance. RESULTS: The overall mean volume fraction of gutta-percha was 68.51 +/- 6.75% for CL, 86.56 +/- 5.00% for UL, and 88.91 +/- 5.16% for WV. Significant differences were found between CL and UL and between CL and WV (p < 0.05), but not between UL and WV (p = 0.526). The gutta-percha density of the roots treated with WV and UL increased towards the coronal aspect, but this trend was not noted in the CL group. CONCLUSIONS: WV compaction and UL compaction produced a significantly denser gutta-percha root filling than CL compaction. The density of gutta-percha was observed to increase towards the coronal aspect when the former two techniques were used.

Quality of root canal fillings using three gutta-percha obturation techniques

OBJECTIVES: The goal of this study was to compare the density of gutta-percha root fillings obturated with the following techniques: cold lateral (CL) compaction, ultrasonic lateral (UL) compaction, and warm vertical (WV) compaction. MATERIALS AND METHODS: Thirty-three extracted mandibular first molars, with two separate mesial canals in each, were selected. After instrumentation, the canals were stratified into three groups based on canal length and curvature, and underwent obturation with one of the techniques. No sealer was used in order to avoid masking any voids. The teeth were imaged pre- and post-obturation using micro-computed tomography. The reconstructed three-dimensional images were analyzed volumetrically to determine the amount of gutta-percha present in every 2 mm segment of the canal. P values < 0.05 were considered to indicate statistical significance. RESULTS: The overall mean volume fraction of gutta-percha was 68.51 +/- 6.75% for CL, 86.56 +/- 5.00% for UL, and 88.91 +/- 5.16% for WV. Significant differences were found between CL and UL and between CL and WV (p < 0.05), but not between UL and WV (p = 0.526). The gutta-percha density of the roots treated with WV and UL increased towards the coronal aspect, but this trend was not noted in the CL group. CONCLUSIONS: WV compaction and UL compaction produced a significantly denser gutta-percha root filling than CL compaction. The density of gutta-percha was observed to increase towards the coronal aspect when the former two techniques were used.

Preference of undergraduate students after first experience on nickel-titanium endodontic instruments

OBJECTIVES: This study aimed to compare two nickel-titanium systems (rotary vs. reciprocating) for their acceptance by undergraduate students who experienced nickel-titanium (NiTi) instruments for the first time. MATERIALS AND METHODS: Eighty-one sophomore dental students were first taught on manual root canal preparation with stainless-steel files. After that, they were instructed on the use of ProTaper Universal system (PTU, Dentsply Maillefer), then the WaveOne (WO, Dentsply Maillefer). They practiced with each system on 2 extracted molars, before using those files to shape the buccal or mesial canals of additional first molars. A questionnaire was completed after using each file system, seeking students' perception about 'Ease of use', 'Flexibility', 'Cutting-efficiency', 'Screwing-effect', 'Feeling-safety', and 'Instrumentation-time' of the NiTi files, relative to stainless-steel instrumentation, on a 5-point Likert-type scale. They were also requested to indicate their preference between the two systems. Data was compared between groups using t-test, and with Chi-square test for correlation of each perception value with the preferred choice (p = 0.05). RESULTS: Among the 81 students, 55 indicated their preferred file system as WO and 22 as PTU. All scores were greater than 4 (better) for both systems, compared with stainless-steel files, except for 'Screwing-effect' for PTU. The scores for WO in the categories of 'Flexibility', 'Screwing-effect', and 'Feeling-safety' were significantly higher scores than those of PTU. A significant association between the 'Screwing-effect' and students' preference for WO was observed. CONCLUSIONS: Novice operators preferred nickel-titanium instruments to stainless-steel, and majority of them opted for reciprocating file instead of continuous rotating system.

Long-term observation of the mineral trioxide aggregate extrusion into the periapical lesion: a case series / 国际口腔科学杂志·英文版

One-step apexification using mineral trioxide aggregate (MTA) has been reported as an alternative treatment modality with more benefits than the use of long-term calcium hydroxide for teeth with open apex. However, orthograde placement of MTA is a challenging procedure in terms of length control. This case series describes the sequence of events following apical extrusion of MTA into the periapical area during a one-step apexification procedure for maxillary central incisor with an infected immature apex. Detailed long-term observation revealed complete resolution of the periapical radiolucent lesion around the extruded MTA. These cases revealed that direct contact with MTA had no negative effects on healing of the periapical tissues. However, intentional MTA overfilling into the periapical lesion is not to be recommended.

Neuroprotective effect of AG490 in experimental traumatic brain injury of rats / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Traumatic brain injury (TBI) is a major cause of death and disability in children and young adults worldwide. Therefore, we investigated the role of AG490 in regulating brain oedema, expression of CD40 and neurological function after TBI.</p><p><b>METHODS</b>Sprague Dawley rats (n = 240) were randomly divided into a sham operation group, TBI+saline group and TBI+AG490 (JAK/STAT inhibitor) group. Members of each group were euthanized at 6, 12, 24 or 72 hours after injury. Neurological severity score (NSS) was used to evaluate the severity of neurological damage. Brain water was quantitated by wet/dry weight method. The expression of CD40 was assessed by flow cytometry.</p><p><b>RESULTS</b>In both the TBI+saline group and the TBI+AG490 group, the brain water content was elevated after TBI, reached a peak at 24-hour and remained high for the rest of the period investigated; the expression of CD40 reached a peak 24 hours after TBI; the NSS was elevated after TBI and then decreased after 6 hours. Elevations in the level of CD40, degree of brain edema and NSS after TBI were significantly reduced in TBI+AG490 group.</p><p><b>CONCLUSION</b>Inhibition of the JAK/STAT signalling pathway reduces brain oedema, decreases the expression of CD40 and exerts neuroprotective effects after TBI.</p>

Ultrasound-guided compression repair for iatrogenic femoral artery pseudoaneurysm / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate relative factors affecting the efficiency of ultrasound-guided compression repair in iatrogenic femoral artery pseudoaneurysm.</p><p><b>METHODS</b>Ultrasound-guided manual compression was performed in 42 patients of iatrogenic femoral artery pseudoaneurysm from June 2004 to June 2010. There were 28 male and 14 female patients, with a mean age of (52 ± 5) years. These patients were presented with femoral artery pseudoaneurysm after catheterisation procedure by percutaneous femoral artery puncture and confirmed by color doppler flow image. Ultrasound-guided manual persistent compression with probe was performed at the puncture site between femoral artery and pseudoaneurysm, until completely thrombosis of pseudoaneurysm, whereas the pseudoaneurysm failed to complete closure required surgical repair.</p><p><b>RESULTS</b>Out of 42 patients, 34 patients (81.0%) were successfully treated by compression resulted in completely thrombosis. There were 8 (19.0%) failures conversion to surgery. Factors associated with success were size of pseudoaneurysm (< 25 mm, 25 - 40 mm, > 40 mm; χ(2) = 13.956, P = 0.001), anti-coagulation status (χ(2) = 5.578, P = 0.010), depth of artery break (< 50 mm, 50 - 80 mm, > 80 mm; χ(2) = 14.055, P = 0.001), pseudoaneurysm communicated with common femoral artery, superficial femoral artery and profunda femoral artery (χ(2) = 8.968, P = 0.011), as well as days to presented with pseudoaneurysm (< 3 d, ≥ 3 d; χ(2) = 5.733, P = 0.012). In multivariate Logistic regression analysis, success by compression was associated with size of pseudoaneurysm (WALD = 5.34, P = 0.021) and with depth of artery break (WALD = 4.84, P = 0.028).</p><p><b>CONCLUSION</b>The ultrasound-guided compression repair of iatrogenic femoral artery pseudoaneurysm is safe, convenient, inexpensive and reliable treatment.</p>

High throughput screening and detection of peptaibol antibiotics from the fermentation broth of tri-choderma harzianum by LC-MS/MS / 中国药学杂志

OBJECTIVE: To identify peptaibol antibiotics from the fermentation broth of Trichoderma harzianum CGMCC No. 1780(China General Microbiological Culture Collection). METHODS: Peptaibol antibiotics were isolated using a bioassay-guided fractionation against Rhizoctonia solani. To purify the peptaibols, the fermentation broth was fractionated by polystyrene resin, sephadex and high performance thin-layer chromatography (HTLC). A specific chromogenic reaction with 4, 4'-methylenebis (N, N-dimethylani-line) was used for the preliminary identification of peptaibols. The sequences of the peptaibol antibiotics were determined by LC-MS/MS analysis. RESULTS: Twenty peptaibol antibiotics were identified from the fermentation broth of T. harzianum and five of the peptaibols were novel. CONCLUSION: The fermentation broth of T. harzianum is a rich source of peptaibol antibiotics warranting further study and the LC-MS/MS method is rapid and effective to analyze the peptaibols.

Effect of sodium phenylbutyrate on the apoptosis of human tongue squamous cancer cell line and expression of p21 and survivin genes / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To examine the effects of sodium phenylbutyrate on the apoptosis of human tongue squamous cancer cell line and expression of p21 and survivin genes.</p><p><b>METHODS</b>The inhibition effects of sodium phenylbutyrate on Tca8113 and human tongue squamous cell carcinoma (TCSSA) cell lines were detected by methyl thiazoly terazolium (MTT) and the apoptosis of the cancer cells after being induced by sodium phenylbutyrate examined by flow cytometry (FCM). The expression of p21 and survivin genes were observed with Western blotting and RT-PCR.</p><p><b>RESULTS</b>Compared with control group, the level of p21 mRNA and protein of Tca8113 cellline increased to 0.09 ± 0.08 and increased 0.72 ± 0.10, that of TCSSA cellline increased 1.34 ± 0.12 and 1.56 ± 0.09 (P < 0.05). Compared with control group, the level of surrive mRNA and protein of Tca8113 cellline decreased to 1.10 ± 0.05 and 1.14 ± 1.10, that of TCSSA cellline decreased to 0.12 ± 0.08 and 0.94 ± 0.09 (P < 0.05). Sodium phenylbutyrate inhibited the cell proliferation, promoted cell apoptosis and arrested the cells in G₁/G₀ phase. The amount of p21 mRNA and protein were increased, and the expression of survivin gene was decreased.</p><p><b>CONCLUSIONS</b>Sodium phenylbutyrate exhibited remarkable inhibitory effects on human tongue squamous cancer cell proliferation and induced cancer cell apoptosis. The mechanism may be due to up-regulation of p21 gene and down-regulation of survivin gene. The mRNA level of p21 gene and survivin gene showed a strong correlation.</p>

Effects of inhibition of ANG-2 expression in Ishikawa cell line / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the effect of RNA interference mediated angiopoietin-2 (ANG-2) gene silencing on human endometrial carcinoma cell line Ishikawa.</p><p><b>METHODS</b>Short hairpin RNA (shRNA) targeting ANG-2 gene was designed and transfected into Ishikawa cells with Lipofectamine 2000. The mRNA and protein expression level of ANG-2, proliferation, morphological changes, apoptosis, cell cycle and invasive ability of the cells after transfection were analyzed.</p><p><b>RESULTS</b>The shRNA targeting the human ANG-2 gene effectively decreased the expression of ANG-2 on both mRNA and protein level, the proliferation inhibition rate of the Ishikawa cells was 63.11%, cell apoptosis was induced, and the cell cycle was arrested in G1 phase. The apoptotic rate of the Ishikawa cells in the transfected group was significantly higher, and the invasive ability was decreased markedly, than that of control groups.</p><p><b>CONCLUSION</b>The shRNA targeting human ANG-2 gene could reduce ANG-2 expression, inhibit cellular growth and invasion in Ishikawa cells in vitro.</p>

Clinical study on treatment of chronic hepatitis B by kurarinone combined with interferon alpha-1b / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To study the clinical effect of combination of kurarinone (KR) and interferon a-lb (IFNalpha-1b) in treating chronic hepatitis B.</p><p><b>METHODS</b>One hundred and forty-six patients with chronic hepatitis B were randomized into four groups. Under the basic conventional treatment, additional KR combined IFNa-lb was given to Group A, IFNa-lb to Group B and KR to Group C while none was given to Group D. The therapeutic course for them was 6 months and succeeded with 6 months of follow-up. Changes in liver histology, expression of transforming growth factor beta (TGF-beta) in liver tissue, and serum levels of TGF-beta, hyaluronic acid (HA), laminin (LN), collagen type IV (IVC), precollagen III (PCIII), as well as the negative conversion rate of HBeAg and HBV DNA, and normalization rate of alanine transaminase (ALT) before and after treatment were observed by immuno chemical method, RIA and ELISA.</p><p><b>RESULTS</b>After treatment, in Group A, the scores of liver fibrosis and all the above-mentioned indexes significantly lowered, as compared with those in Group B and C, the difference was significant (P<0.05 or P<0.01). The negative conversion rate of TGF-beta in liver tissue was in accordance with the dynamic change of liver fibrosis. Comparison between Group B and C in those aspects showed insignificant difference (P >0.05).</p><p><b>CONCLUSION</b>KR combined with IFNalpha-1b shows better effect in treating chronic hepatitis B than that of using either of the two alone.</p>