通过对口腔实验教学中心建设模式的思考和实践,提出了构建"基础与临床相结合,仿真与现实结合,科研与教学相结合,以能力培养为核心,以师生互动为主要教学方式,以提高学生综合素质为目标"的口腔实验教学模式。并建立了完善的实验教学平台,在实验教材、实验项目、教学手段和教学方法等进行了全方位的实践探索。

Objective:To detect the differently-expressed genes of S.mutans cultured in 0.5% and 1% sucrose by microarray technique.Methods:Gene chips were constructed and the gene expressions of S.mutans under different conditions were detected.Results:In 0.5% sucrose environment,compared with 1.0% sucrose environment,expressions of about 40 S.mutans genes were changed.23 genes associated with virulence,pathogenesis,bacterial component metabolism,and so on,were down-regulated.While 17 genes related to sugar transport and energy metabolism were up-regulated.Conclusion:Regulation of S.mutans by environment factors is very complex and is a result of cooperations of multifactors and multigenes.Microarray technique is efficient to detect differently expressed genes in S.mutans.

Objectives To evaluate the effect of different carbohydrates in the broth on the acidogenicity of the Streptococcus mutans isolates.Methods Twenty-eight strains of S.mutans (serotype C) were used,acquired from the previous study.The strains were inoculated in TPY broth containing glucose or sucrose,and anaerobicly cultured for 24h.The pH values before inoculation and terminal pH values were measured with pH elecotrode,and the pH values were determined as the acidogenic abilities of the strains.The acidogenicity difference among strains cultured with different carbohydrates was evaluated by t test.Results The acidogenic abilities of the strains were not significantly different when cultured with glucose or sucrose.The strains from caries-free individuals produced more acid when cultured with sucrose than cultured with glucose (P<0.05).Conclusion The cariogenic effect of sucrose is more prominent on the strains from caries-free individuals.

Objective. To evaluate the pulpal response of beagles following direct pulp capping with Clearfil SE Bond (SB), a self-etching adhesive. Study design. One hundred thirty sound teeth from 6 male beagles were used. One hundred twenty teeth had their pulp mechanically exposed at the bottom of the class V cavities and were divided into 2 groups. In group 1, teeth were capped with SB; group 2 teeth were capped with calcium hydroxide cement (CH). Ten teeth were kept intact as an untreated control group. After 7, 30, and 90 days, 40 teeth from 2 beagles were extracted and processed for light microscopic examination. Results. After the 7-day observation period, inflammatory reaction in the SB group was similar to that of the CH group (P > .05). After the 30-day and 90-day observation periods, inflammatory reaction was slight in both groups, but less dentin bridge formation was observed in specimens from the SB group than in those from the CH group (P < .05). Conclusion. SB showed good biocompatibility with pulp, but its ability to induce reparative dentin was lower than that of CH. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006;102:e78-e84)

变形链球菌能适应不断变化的口腔环境并在其中生存,故而与龋病的发生密切相关。环境应激反应使变形链球菌的多种基因和蛋白质表达水平发生改变,涉及细菌的物质代谢、细胞修复及细胞信号传导系统等多方面。对环境应激反应时变形链球菌毒力因子表达变化的研究可更深入了解其致龋机制。本文就近年来对变链应激反应的分子生物学研究做一综述。

OBJECTIVE To evaluate the beagles' pulp response following direct pulp capping with Clearfil SE BOND (SB). METHODS 130 sound teeth were used. 120 had their pulps mechanically exposed and were divided in two groups. In group A, teeth were capped with SB. In group B, teeth were capped with calcium hydroxide (CH). The left 10 teeth were used as control. After 7, 30 and 90 days, the teeth were extracted and processed for light microscopical examination. RESULTS In 7 day observation period, inflammatory reaction in SB group was slighter than that of CH group, but the difference was statistical insignificant. In the 30 day and 90 day observation period, inflammatory reaction was slight in both groups, but specimens with dentin bridge formation was significantly less in SB group than in CH group (P < 0.05). CONCLUSION SB showed acceptable biocompatibility with pulp, but its ability to induce hard tissue barrier on pulp exposure is weaker than CH.

目的:对可乐丽菲露SE BOND在人体用于直接盖髓术进行组织学评价.方法:选择24名志愿者共45颗健康人第三磨牙,41颗在(牙合)面制备Ⅰ类洞并在洞底作人工穿髓孔,然后分为2组,实验组以可乐丽菲露SE BOND盖髓,对照组以氢氧化钙盖髓.4颗作为空白对照.所有实验牙齿分别在盖髓后的7、30、90 d后拔除并进行组织学检测.结果:实验组和对照组志愿者均未出现术后实验牙齿敏感症状.病理检测显示,在7d和30 d的观察期内2组均有轻度到中度的炎性反应,但可乐丽菲露SE BOND组的炎性反应较氢氧化钙组轻,其组织学评价分级上的差别有统计学意义(P＜0.05).在90 d的观察期内2组均无明显的炎性反应,而牙本质桥的形成在氢氧化钙组显著多于可乐丽菲露SE BOND组,氢氧化钙组7例标本中有6例标本有牙本质桥的形成,可乐丽菲露SE BOND组7例标本中有3例形成,其差别有统计学意义(P＜0.05).结论:可乐丽菲露SE BOND对牙髓的刺激性较小,但诱导牙本质形成的能力较氢氧化钙弱.

OBJECTIVE:To estimate the related factors and prophylactic measures of endodontic interappointment emergencies (EIE). METHODS:The clinical cases were divided into three groups. Cases in the routine group were treated according to the routine procedures of root canal therapy. Cases in the medicament group took dexamethasone tablets after the instrumentation. Root canals in the drainage group were prepared at the first visit and had been left open for two or three days. The related factors were recorded. The incidences and flare-up index (FUI) value of EIE were statistically analyzed. RESULTS:The EIE incidence of the routine group was 19.1%. The EIE incidence and FUI value of the overinstrumented teeth were significantly higher than those of other teeth (P < 0.05). EIE were not significantly related to the age, gender, tooth location and pathosis of the pulpal and periapical tissue (P > 0.05). The FUI value of the medicament group was significantly lower than that of the routine group (P < 0.05). Less severe EIE occurred in the cases of the drainage group than those of the control group (P > 0.05). CONCLUSION:The occurrence of EIE was significantly related to overinstrumentation. Taking dexamethasone may relieve EIE.

本文通过检测变形链球菌(简称变链，Streptococcus mutans)临床株在培养基不同pH条件下乳酸脱氢酶(lactate dehydrogenase, LDH)的基因表达量，初讨生长环境对变链ldh基因表达的调节作用。实验选择产酸能力不同、分离自无龋者及龋易感者口腔20株变链临床菌株为研究对象，在不同初始pH培养基中厌氧培养，实时荧光定量PCR检测变链在不同初始pH值下生长时ldh基因表达的相对倍数。结果显示，在初始pH7.0、含50mmol/L葡萄糖培养基中，不同产酸能力变链临床株ldh基因表达水平无显著差异。当生长环境pH值降低至pH5.5时，低产酸菌株ldh基因表达显著高于高产酸菌株。可见，变链临床株产酸能力及耐酸生长受其生长环境条件影响，在低pH条件下，变链ldh基因表达水平提高以适应生存，从而增强其致龋性。