自粘结树脂水门汀粘结牙本质的超微结构观察

目的：通过扫描电镜比较4种树脂水门汀（RelyX Unicem、PanaviaF、VariolinkⅡ、Vitique）粘结牙本质时超微结构的差异。方法：新鲜拔除的人无龋坏第三磨牙12颗,随机分为4组（n=3）,制备牙本质粘结面,分别与4种树脂水门汀（RelyX Unicem、PanaviaF、VariolinkⅡ、Vitique）粘结处理,将所得粘结试件二次纵切,SEM观察牙本质粘结界面。结果：四种树脂水门汀与牙本质粘结中,RelyXUnicem未见明显树脂突,而PanaviaF、VariolinkⅡ和Vitique均可见明显树脂突形成。结论：新型自粘结树脂水门汀粘结牙本质的超微结构完全有别于传统树脂水门汀。     

蛋白聚糖在维持牙本质胶原空间形貌和水合性能方面的作用

目的:评价牙本质蛋白聚糖对脱矿牙本质胶原纤维形貌和水合性能的影响。方法:新鲜拔除无龋坏人磨牙牙本质酸蚀后分别用胰蛋白酶和硫酸软骨素酶ABC孵育去除牙本质蛋白聚糖和糖胺聚糖侧链,对照组与实验组处理方法相同,但孵育液中不添加酶。然后在牙本质表面不同润湿状态下用场发射扫描电镜和激光共聚焦扫描电镜分别观察牙本质的微观形貌并评价脱矿牙本质的水合性能。结果:硫酸软骨素酶ABC和TRY酶处理改变了牙本质的微观形貌,使胶原纤维间距增大。酶处理、牙本质表面润湿性及两者的交互作用均会显著影响脱矿牙本质的厚度(P0.0001)。结论:牙本质蛋白聚糖和糖胺聚糖侧链在维持牙本质胶原纤维网的空间结构和水合作用方面均发挥着重要作用。蛋白聚糖、胶原纤维-蛋白聚糖以及蛋白聚糖-蛋白聚糖间的的亲水性是影响脱矿牙本质围观形貌和厚度的重要因素。     

Er,Cr:YSGG激光处理正常及龋坏牙本质的扫描电镜观察

目的：利用扫描电镜观察Er,Cr：YSGG激光处理龋坏牙本质的形态学改变,并与常规方法进行比较。方法：将24颗新拔除的患龋牙随机分成2组,每组12颗牙。第1组常规处理组：分别用金刚砂石针、碳钢裂钻和挖器处理正常及龋坏牙本质;第2组激光处理组：分别用2WEr,Cr：YSGG激光、4WEr,Cr：YSGG激光处理正常及龋坏牙本质。常规制片,扫描电镜下观察。结果：与常规方法相比,激光处理后的牙本质表面不平,呈鱼鳞状、片状的粗糙外观;表面清洁,无玷污层,牙本质小管口清晰可见;4W激光作用时偶见微裂;激光处理后的牙本质表面具有增加树脂黏结性的形态学改变．结论：Er,Cr：YSGG激光能有效地清除龋坏牙本质及玷污层,并可使牙体组织发生一定的形态学改变。因此,Er,Cr：YSGG激光能够替代常规去龋备洞方法。     

骨涎蛋白在大鼠磨牙第三期牙本质形成过程中的表达

目的:观察大鼠牙髓修复第三期牙本质形成过程中骨涎蛋白(bone sialoprotein,BSP)的表达变化及意义。方法:选取6周龄雄性Wistar大鼠10只,建立实验大鼠模型,利用免疫组化法检测大鼠第三期牙本质中骨涎蛋白的表达情况。结果:盖髓2周后,在盖髓处下方有第三期牙本质形成。与原发性牙本质(PD)相比,第三期牙本质小管数目少且形态不规则。BSP在原发性牙本质中没有表达,但在盖髓下方和髓角下第三期牙本质中都有表达。结论:BSP可能通过参与羟基磷灰石(HA)的形成以及调节新分化的成牙本质细胞向新形成的牙本质基质的粘附来参与早期的第三期牙本质的生成。     

不同箍结构对纤维桩核修复冠方微渗漏的影响

目的:研究不同形态的箍结构对纤维桩核修复冠方微渗漏的影响。方法:选择因正畸治疗需要而拔除的下颌单根管前磨牙50颗,随机分成5个组:完整箍结构组(第1组)、1面缺损的箍结构组(第2组)、2面缺损的箍结构组(第3组)、3面缺损的箍结构组(第4组)以及无箍结构组(第5组)。所有标本经纤维桩核修复后模拟口内老化情况,并经染色处理,在体式显微镜下记录各组微渗漏的情况。结果:第1组的微渗漏情况最轻,第5组的微渗漏情况最重。第1、2、3组之间微渗漏情况无统计学差异(P0.05),第2、3组和第4组之间微渗漏情况均无统计学差异(P0.05)。但第1组和第4、5组间微渗漏差异有统计学意义(P0.05),第2、3组和第5组间微渗漏差异有统计学意义(P0.05)。结论:牙体修复时至少应保留一面牙本质肩领,即使在没有完整箍结构的情况下也能获得良好的修复效果。     

不同去龋技术在乳牙龋病治疗中的应用疗效分析

目的:比较传统机械切割法、非创伤性充填法(atraumatic restorative treatment,ART)和Carisolv化学法在临床乳牙龋病治疗中的应用效果差异。方法:选取2011年1月-2012年6月来我科就诊的5-8岁儿牙患者96名,患牙180颗,随机分为3个不同的治疗组:传统机械去龋组、ART组和Carisolv化学去龋组进行相应牙体充填治疗,通过去龋效果、去龋时间、术中疼痛发生率和术后长期疗效等方面比较不同去龋技术之间的差异。结果:常规机械去龋组和Carisolv组的去龋效果明显优于ART组(P0.05),二者之间无明显差异(P0.05);3种去龋方法的去龋操作时间无明显差异(P0.05);Carisolv组和ART组去龋治疗中患儿术中疼痛发生例数明显低于常规机械去龋组(P0.05),二者之间无明显差异(P0.05);治疗1年后的复诊发现,常规机械去龋组和Carisolv组中患牙继发龋发生率明显低于ART组(P0.05),二者之间无明显差异(P0.05);三种方法治疗后患牙充填物折断/脱落发生率无明显差异(P0.05)。结论:Carisolv化学去龋法能有效减轻术中疼痛和术后复发率,值得在临床乳牙治疗中推广应用;ART的去龋效果和远期疗效可能限制其广泛应用。     

高龋菌株产生的变链素对口腔链球菌抑制活性的比较

目的 通过比较高龋和无龋儿童变形链球菌临床分离株产生的变链素对口腔链球菌的抑制活性,探讨变链素的产生与其致龋性及口腔微生态的关系.方法 从10例高龋儿童和10例无龋儿童牙菌斑内分离、鉴定得到80株变形链球菌临床分离株,分为高龋组和无龋组.用平板法检测两组菌株产生的变链素对口腔链球菌Streptococcus oralis ATCC 10557的抑制情况,观察两组菌株产生的抑菌环大小, 测量记录数据,T检验比较两组菌株抑菌环均数差异.结果 高龋组产生的抑菌环平均值为10.4 mm,无龋组平均值为6.9 mm,T检验显示差异具有显著性(t值为3.098,P<0.05).结论 高龋菌株产生的变链素对ATCC 10557有更大的抑制活性,变链素对口腔链球菌的抑制活性与其致龋力呈正相关.     

光学相干成像技术无创监测Er:YAG激光消融后人牙本质表面变性层

为探讨利用光学相干成像技术(OCT)定量评估Er:YAG激光消融后牙本质表面特征的可行性,以人无龋第三磨牙为试验样品,制备牙本质圆盘,用50μs超短脉宽Er:YAG激光在水喷雾下垂直切削牙本质表面,对照组为金刚砂球钻切削和砂纸抛光组,OCT观察表层性状及测量表层光强改变,组织病理切片分析表层结构;表面切削后使用37%磷酸蚀刻30 s,扫描电镜(SEM)观察表面形貌,能量色散X射线光谱仪(EDX)测量表面元素组成。OCT显示,所有试验组牙本质表层光散射特性均发生改变,可见高亮层形成,激光组高亮层厚度高于砂纸组和球钻组(P0.05)。组织切片显示,激光组表层可见连续的嗜碱性深染改性层,球钻组及砂纸组改性层少且不连续,改性层厚度与OCT高亮层结果相关。SEM显示,酸蚀后激光组牙本质小管开口扩大,但未见胶原纤维网暴露。酸处理后激光组的钙、磷含量均高于砂纸及球钻组(P0.05),这意味着受激光影响的牙本质变得更耐酸。研究结果表明,OCT可能成为一种可精确评估牙本质表层特性的无创性工具,这将有助于牙医确定粘接修复策略。     

Er:YAG激光处理对牙釉质及牙本质修复效果的影响

研究不同表面处理条件下Er:YAG激光照射对牙釉质及牙本质修复效果的影响。80个样本随机分成牙釉质和牙本质2大组,再根据处理方式随机分为4小组:①酸蚀(37%磷酸);②Er:YAG激光;③自酸蚀粘接处理剂;④Er:YAG激光+自酸蚀粘接处理剂。与树脂加强型玻璃离子水门汀(RMGIC)粘接后37℃水浴中储存24 h,用万能测试机测定粘接剪切强度。牙釉质及牙本质组结果均为3、4小组粘结强度接近(P0.05),显著高于其他组(P0.05),1、2小组间粘结强度差别无统计学差异(P0.05)。Er:YAG激光照射可替代37%磷酸酸蚀处理方法;G-Bond自酸蚀粘接处理剂可提高牙面与RMGIC间的粘结力,Er:YAG激光处理不影响该效果。     

儿童牙齿表面的菌群分布与龋齿的关系

本实验从幼儿园和小学一年级的学生中选择５－８岁的无龋齿和有龋齿的儿童各４５例,进行牙齿表面的菌群分布与龋齿关系的研究,结果在有龋组中分离到变形链球菌８株,放线菌６株及拟杆菌２６株,而在无龋组中未分离到变形链球菌,分离到放线菌１株,拟杆菌１４株,两组比较,以上三种菌有显著差异（Ｘ２检验Ｐ＜０．０５）。说明除变形链球菌是主要的致龋菌外〔１,２〕,还应考虑放线菌和拟杆菌在龋齿发生上的作用。此外,我们还发现两组的兼性厌氧菌的分布也有所不同,无龋组中分离到棒状杆菌２９株,而有龋组中分离到棒状杆菌１１株,小肠结肠炎耶尔森氏菌７株,两组也有明显差异,故我们认为龋齿发生的原因可能是多方面的,就病原菌来说,也可能是多种细菌的混合作用,从两组兼性厌氧菌与无芽胞厌氧菌的分布不同来看,亦应考虑龋齿的发生与口腔内生态平衡有关     

Immunohistochemical Analysis of Matrix Metalloproteinase-13 in Human Caries Dentin

The immunoexpression profile of matrix metalloproteinase-13 was investigated for the first time in dentin of human caries and healthy teeth. Twelve permanent premolars (10 caries and 2 sound) were decalcified in ethylenediaminetetraacetic acid and processed for embedding in paraffin wax. Sections 3-4 µm in thickness were cut and processed for immunohistochemistry. A mouse monoclonal anti-metalloproteinase-13 antibody was used for localisation using an immunoperoxidase technique. Dentinal immunoreactivity was detected in all teeth; it was weak in sound teeth and strong close to the caries area. These in vivo findings suggest a role for metalloproteinase-13 in the development and progression of adult human dental tissue disorders.Key words: Human teeth, caries, MMP-13, dentin, immunohistochemistry     

Aluminum concentrations in human deciduous enamel and dentin related to dental caries

The aluminum (Al) concentrations in the enamel and dentin of 314 human deciduous teeth were determined in order to examine the relationship between Al and dental caries. The sample teeth were divided into three groups: the sound tooth group, carious tooth group and filled tooth group. The teeth of the carious tooth group were further classified into three groups depending on the stage of caries. The Al content was determined using graphite furnace atomic absorption spectrometry. In both the enamel and dentin, the Al concentrations were unaffected by sex, but did depend on tooth type. In enamel, the Al concentration was significantly higher in the sound tooth group (42.8 +/- 37.3 microg/g) than in the three carious groups (20.7 +/- 17.1-24.9 +/- 22.0 microg/g) and the filled tooth group (27.3 +/- 25.5 microg/g). As for dentin, the Al concentration was also significantly higher in the sound tooth group (36.2 +/- 35.1 microg/g) than in the three carious groups (15.1 +/- 13.3-24.5 +/- 23.4 microg/g) and the filled tooth group (17.2 +/- 20.6 microg/g). Even when analyzing incisors alone, the Al concentrations were significantly higher in the sound tooth group than in the other groups, for both enamel and dentin. Furthermore, the Al levels in carious enamel and dentin did not decrease with the advance of caries. These findings indicated that the deciduous teeth containing higher Al concentrations on average had less caries than the teeth with lower Al concentrations, and suggest that Al acts as a possible cariostatic agent by itself.     

Apoptosis Activation in Human Carious Dentin. An Immunohistochemical Study

The exact mechanisms and enzymes involved in caries progression are largely unclear. Apoptosis plays a key role in dentin remodelling related to damage repair; however, it is unclear whether apoptosis in decayed teeth is activated through the extrinsic or the intrinsic pathway. This ex vivo immunohistochemical study explored the localization of TRAIL, DR5, Bcl-2 and Bax, the main proteins involved in apoptosis, in teeth with advanced caries. To evaluate TRAIL, DR5, Bcl-2 and Bax immunoexpressions twelve permanent carious premolars were embedded in paraffin and processed for immunohistochemistry. The results showed that TRAIL and DR5 were overexpressed in dentin and in pulp vessels and mononuclear cells; strong Bax immunostaining was detected in dilated dentinal tubules close to the lesion, and Bcl-2 staining was weak in some dentin areas under the cavity or altogether absent. These findings suggest that both apoptosis pathways are activated in dental caries. Further studies are required to gain insights into its biomolecular mechanisms.Key words: Apoptosis, TRAIL, DR5, Bax, Bcl-2, carious teeth     

广西敢造遗址史前居民口腔的健康状况

广西扶绥敢造遗址是华南新石器时代一处典型的河岸贝丘遗址,其人骨测年结果的上限为8488 BC,下限为6492 BC。本文对敢造遗址2014年出土的108例个体的999枚恒齿进行观察统计,结果显示居民的饮食结构应是以肉食为主并辅以富含淀粉的块茎类植物。该遗址居民的龋齿率高于部分农业人群,但远低于同为华南渔猎—采集经济的鲤鱼墩、甑皮岩和顶蛳山遗址,其原因应与食用块茎类植物的多寡有关。较高的牙结石罹患率(89.86%)可能与鱼类、贝类等高蛋白饮食有关。相比农业、游牧或狩猎人群,该遗址居民偏重的牙齿磨耗可能与食用含沙量较大的螺类、贝类等有关;肉类食物的食用导致该遗址居民上颌前部牙齿磨耗重于后部牙齿,而“上颌前部牙齿舌侧过度磨耗”现象的出现则与食用块茎类植物有关。     

An <Emphasis Type="Italic">in vitro</Emphasis> microbial model associated with sucrose to produce dentin caries lesions

The complexity of the oral environment and ethical issues have prompted the development of an in vitro bacterial model to evaluate the effect of frequency of sucrose exposure on dentin caries formation, biofilm composition, and pH changes. In the experiment, dentin specimens (n=45) were randomly divided into four groups: control (C), negative control (0S), 3S (three sucrose baths), and 6S (six sucrose baths). The specimens then were inoculated with Streptococcus mutans and treated according to the protocol described below. Dentin demineralization and lesion depth were assessed by transverse microradiography. Extracellular polysaccharides that formed in the biofilm were analyzed and counts of microorganisms in the carious dentin were measured. After a 7-day period of growth, the biofilm pH was assessed before and after sucrose baths (n=5). The addition of sucrose led to dentin caries development regardless of the number of sucrose baths performed. The number of colony forming units (cfu) from the carious dentin did not differ among the treatment groups, though the extracellular polysaccharides from both 3S and 6S differed from 0S. The pH decreased immediately after the sucrose bath but increased again after 5 min. We demonstrate here that the in vitro microbial model for the study of dentin caries formation is reproducible and able to produce dentin caries, irrespective of the frequency of sucrose exposure.     

Hereditary and environmental dental findings in identification of human remains

The paper presents the results on hereditary and environmental dental findings in identification of human remains exhumed from mass graves in the Republic of Croatia. The total of 17,880 teeth from all the categories (incisors, canines, premolars and molars) was examined. Hereditary findings of the teeth such as shape, size, position, as well as age were used in all of the cases confirming and completing the identification. In only 15% of the cases they were the starting points for the identification that would be later confirmed with another 3-5 traditional identification procedures. Disturbances in tooth eruption were recorded in 22% of the cases, impaction of teeth in 10%, and retarded eruption of teeth in 12%. Disturbances of tooth position were recorded in 65% of the cases. Tooth rotation in 26% and diastema mediana in maxilla or mandible in 39%. Disorders of tooth number in the form of unilateral and bilateral missing of lateral maxillary incisors were recorded only in 2% of the monitored cases. Abnormalities of the tooth shape were found in 11% of the cases. The majority of them were found on the tooth crowns 6%, and less on the tooth roots 5%. Environmental dental findings that were the most significant for the identifications were prosthetic appliances in 30% of cases. Prostheses were helpful in the identification of 3% of the cases, while crowns and bridges were helpful in 27% of the cases. Ante mortem teeth extractions were helpful in 25% of the cases. Teeth restorations were recorded in 20% of the identified cases, amalgams in 19% and aesthetic filings in 1%. Dental caries was helpful in only 10% of the cases, superficial caries in 3% and caries of dentin in 7% of cases.     

Oral health among institutionalised elderly in Zagreb, Croatia

Objective: A survey of dental health status was conducted in the institutionalised elderly in Zagreb, Croatia in order to assess the dental and oral health of the elderly population. Participants: In 139 institutionalised elderly from a single nursing home in Zagreb, dental and oral status was registered according to World Health Organization criteria. There were 108 (77.7%) female and 31 (22.3%) male subjects aged 58–99 years. Results: The results showed that 45.3% of the interviewed persons were totally edentulous in both jaws. A significant increase in prevalence of edentulousness with the increasing age was recorded. The mean decayed, missing and filled teeth number was 27. The average number of teeth with caries was 1.03 per person, the number of the teeth extracted was 6.9 per person and teeth with fillings 0.74 per person. The average number of teeth with root caries was 0.17. Approximately 9 teeth per person were in need of treatment. Filled teeth were found 25.9% of subjects and decayed teeth in 30.9%. The mean number of remaining sound teeth, decayed teeth and residual roots in the elderly decreased with increasing age. Complete periodontal treatment was required in 5.8% of the participants and no significant differences between genders in periodontal status could be noticed. Conclusion: The results of this study suggest poor dental health in this group of the institutionalised elderly and the necessity of improving and implementing some special features in the dental health services programs for the institutionalised elderly.     

不同剂量的多乐氟对学龄前儿童尿氟浓度的影响

目的:观察儿童使用不同剂量的多乐氟氟化钠护齿剂(Duraphat)对其尿氟浓度的影响,为Duraphat应用于群防群治提供理论依据。方法:采用氟离子选择电极法,将53名3~4岁儿童按班别分成三组,分别使用0.2 m L及0.05 m L Duraphat涂布儿童牙齿,检测涂氟前和涂氟后1、2、3 d的尿氟浓度,并进行组内和组间比较。结果:各组使用Duraphat后尿氟浓度逐渐增加,涂氟后2 h开始与涂氟前比较差异均有统计学意义(P0.05),涂氟后3~4 h尿氟浓度达到高峰,至21 h后与涂氟前比较差异无统计学意义(P0.05);3岁0.2 m L组与0.05 m L组在涂氟后2~4 h的尿氟浓度比较差异有显著性(P0.05),其他时间比较均无显著性差异(P0.05);0.05 m L3岁组与4岁组比较尿氟浓度无明显差别(P0.05);3岁初次用氟组和4岁多次用氟组涂氟前尿氟无显著差异(P0.05)。结论:儿童口腔局部用氟对其尿氟浓度有影响,随局部用氟剂量的增加而增加;年龄对儿童尿氟浓度无明显影响;Duraphat在体内无远期氟蓄积,在一定剂量内使用Duraphat可起到较好的防龋效果。     

Bone morphogenetic proteins in dentin regeneration for potential use in endodontic therapy

The human dentition is indispensable for nutrition and physiology. The teeth have evolved for mastication of food. Caries is a common dental problem in which the dentin matrix is damaged. When the caries is deep and the dental pulp is exposed, the pulp has to be removed in many cases, resulting ultimately in loss of the tooth. Therefore, the regeneration of dentin-pulp complex is the long-term goal of operative dentistry and endodontics. The key elements of dentin regeneration are stem cells, morphogens such as bone morphogenetic proteins (BMPs) and a scaffold of extracellular matrix. The dental pulp has stem/progenitor cells that have the potential to differentiate into dentin-forming odontoblasts in response to BMPs. Pulpal wound healing consists of stem/progenitor cells release from dental pulp niche after noxious stimuli such as caries, migration to the injured site, proliferation and differentiation into odontoblasts. There are two main strategies for pulp therapy to regenerate dentin: (1) in vivo method of enhancing the natural healing potential of pulp tissue by application of BMP proteins or BMP genes, (2) ex vivo method of isolation of stem/progenitor cells, differentiation with BMP proteins or BMP genes and transplantation to the tooth. This review summarizes recent advances in application of BMPs for dentin regeneration and possible use in endodotic therapy.