Objective To determine the expression level of each gtf under various conditions and its relationship with the ability to produce extracellular polysacchradides(EPS) in different strains of S.mutans. Methods Twenty strains of S.mutans of clinical isolations with different EPS producibility and UA159 were selected,and their ability to produce EPS under 1% sucrose and 2% sucrose were tested.Then in two strains,the relative quantity of gtfA,B,C,D's mRNA were examined by real-time PCR methods. Results In all strains,the quantity of EPS was prominently enhanced by sucrose.The expression levels of gtfA,B,C,D were increased in 1% sucrose in both strains.In 2% sucrose,the expression levels of gtfB,C,D were decreased and gtfA was increased in the strain which produced less EPS.gtfB,D were decreased and gtfA,C were increased in the strain which produced more EPS. Conclusion The expression level of gtfs from S.mutants and its ability to produce extracellular polysaccharides were influenced by sucrose concentration.

OBJECTIVE To determine the expression level of each gtf under different pH cultural conditions and to find the relationship between gtf expression levels with environmental pH in different strains of Streptococcus mutans (S.mutans). METHODS S. mutans form clinical isolation with different extracellular polysaccharides (EPS) producibility and UA159 were selected. Their ability to produce EPS under pH5.5 and pH7 were tested. Then in two strains, the relative quantity of gtfA, gtfB, gtfC, gtfD's mRNA which were related to S. mutan's ability to produce EPC, were examined by real-time reverse transcription-polymerase chain reaction (real-time RT-PCR) methods under different pH culture condition. RESULTS At pH5.5, expression levels of gtfA, gtfB, gtfD were increased while that of gtfC were decreased in both strains, and that of gtfB, gtfC were higher in strain which produces more ECP. CONCLUSION The expression levels of gtfs related closely to the cariogenicity of S. mutan.

Objective To analyze the reasons for retreating resinified teeth and the factors that may lead to the failure of resinified teeth.MethodsA total of 296 failed resinified teeth were randomly selected and included in this study.The causes of failure,tooth position,resinified duration and the age of the patient were recorded and the data analyzed.ResultsTeeth fracture accounted for 30.41%,which was the major cause for retreatment,followed by missing of fillings(26.01%)and chronic apical periodontitis(20.95%).69.59% were molars;84.12% of the teeth which needed retreatment had received resinifying treatment for 5-10 years;64.19% of the resinified teeth were from 30-60 years old patients.ConclusionMissing of restoration and teeth fracture were the main causes for the retreatment of resinified teeth.Long-time results of resinifying treatment were not good.

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)

Objective To evaluate the feasibility of applying Clearfil AP-X composite resin to restore deep cavities of vital teeth without bases by cytotoxicity test on primary human pulp cells.Methods Normal dental pulp of teenagers were collected and cultured by tissue explant methods. The restorative materials Clearfil AP-X composite resin, composite resin Z100, compomer F2000 and their adhesive materials, as well as Vitremer were designed as columns which were 5mm in diameter and 2mm in depth, then the eluates of the materials were prepared. MTT method was used to evaluate the cytotoxicity of dental materials on human pulp cells.Results Cytotoxicity: Glass ionomer Cement Vitremer > composite resin Z100>Clearfil AP-X composite resin and compomer F2000.The difference is statistically significant(P<0.05). The cytotoxicity of adhesive of F2000>Clearfil SE BOND and adhensive of Z100.The difference is statistically significant(P<0.05).Conclusion The Cytotoxicity of Clearfil AP-X composite resin and SE BOND is less than that of the commonly used teeth-colored restoring materials and their adhesives.

当人类基因组和多种生物的全基因组测序完成的时候,科学家们面临一个巨大的挑战,即基因在序列上的变化是怎样影响它的表达和生物学功能的。基因芯片提供了一种能够同时研究成千上万个基因的时空表达与生物学现象关系的强有力的工具。本文就基因芯片的结构与应用作一综述。

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.

目的通过对可乐丽菲露AP-X复合树脂及复合体F2000临床疗效比较,为可乐丽菲露AP-X复合树脂的临床应用提供临床试验依据.方法选择楔状缺损患牙74颗,随机分为可乐丽菲露AP-X复合树脂组与复合体F2000组,每组37颗,分别由同一操作者按照厂商使用说明书进行充填治疗.6个月后复诊,进行评价,计算失败、缺陷、成功率.结果可乐丽菲露充填组有2例脱落,2例边缘着色,成功率87.10%;复合体F2000充填组有2例脱落,3例边缘着色,成功率83.87%;无统计学差异(P＞0.05).结论可乐丽菲露AP-X复合树脂可以用于临床窝洞的直接充填.

牙本质粘接修复的效果影响到修复成功率及修复质量.本文就牙本质的粘接材料、窝洞预备方法、洞型、验力等因素对牙本质粘接修复效果的影响作一综述,这有助于临床医生在此基础上提高修复质量.