Objective To compare the fracture resistances of teeth restored with 3 different posts-core and failure modes. Methods 54lower premolarsendodontically treated teeth were selected for thisstudy and divided into three groups randomly (without ferrule, 1 mm ferrule and 2 mm ferrule). Each group was then divided into 3 sub-groups (6 teeth in each group) and restored with cast post-core, glass fiberpost-core, andceramic post-core respectively. After thermocycling specimens , the fracture resistance was measured using a cyclic fatigue testing machine. Data were analyzed with 2-way ANOVA (α = 0.05). Results Fiber post-core group exhibited significantly higher resistance to fracture compared with groups of cast post-core and ceramic post-core (P<0.05). Preparing dentin ferrules increased significantly fatigue resistance (P < 0.05). Conclusions Glassfiber posts were able to preserve and reinforce the remaining tooth structures. Dentin ferrule preparation is necessary to enhancefractureresistance.

Objective To study the clinical values of polyvinyl alcohol chemoembolization and bronchial arterial infusion(BAI) in interventional therapy of central bronchogenic carcinoma.Methods 45 pathologically proved cases of central bronchogenic carcinoma in mid or late period were randomly divided into two groups(control group in 24 cases and experimental group in 21 cases).After detecting the nourishing arteries of bronchogenic carcinoma with angiography,the treating processes were performed.Control group : anticancer drugs were poured into bronchial artery.Experimental group : the feeding arteries of tumors were co-axially superselective catheterized with microcatheters,the anti-neoplasm agents were poured into everyone of feeding arteries according to the blood supply,then the feeding arteries were embolized by polyvinyl alcohol.Results Control group : the obvious effective rate(CR+PR) was 50%.Experimental group:the obvious effective rate was 90.4%.Two cases in control group obtained the chances of radical operation and chemotherapy were performed after operation,the other 22 cases were undergone synthetic treatment.Seven cases in experimental group obtained the chances of radical operation and chemotherapy were performed after operation,14 cases were undergone synthetic treatment.Three cases in control group died and none of in experimental group died in the follow-up of 2~24 months.Conclusion The short-term effect of polyvinyl alcohol embolization is better than those of BAI for interventional therapy of central bronchogenic cancer,but the long-term effect needs a large number of cases to access the real clinical value.

Objective To investigate human pulpal response to mineral trioxide aggregate (MTA) and calcium hydroxide (CH) as pulp capping agents. Methods This study was conducted on 90 intact first and second premolars of human maxillary and mandibular teeth of 30 volunteers. The patients were randomly assigned into three groups with 10 in each group. Under local anesthesia, the teeth were exposed and capped either with MTA, or CH. After 30, 60, and 90 days, 10 teeth of each group were extracted and prepared for histologic ob-servation. The data were analyzed with Wilcoxon rank sum test and paired t-tests (α = 0.05). Results MTA had a higher success rate and resulted in less pulpal inflammatory response and more predictable hard dentin bridge formation than CH (P < 0.05). Conclusion MTA appears to be a suitable replacement for CH in direct pulp capping.