Monitoring time-related trends in dental caries in permanent teeth in Japanese national surveys

Objectives: According to dental examinations of 3‐ and 12‐year‐old children conducted throughout Japan, the prevalence of dental caries in children is decreasing. However, little is known about changes in the prevalence of dental caries in adults. This study analysed past and present prevalences of dental caries in permanent teeth and predicted future trends in dental caries in adults. Methods: Data were sourced from nine national dental surveys conducted in Japan at 6‐year intervals from 1957 to 2005. Data from oral examinations were recorded as indices of decayed, missing and filled teeth. Results: The mean number of filled teeth increased markedly, whereas mean numbers of decayed teeth and missing teeth decreased substantially in people aged ≥ 40 years. By contrast, the mean number of filled teeth first increased and then decreased in groups aged 5–39 years. Conclusions: Among Japanese respondents sampled in a series of cross‐sectional studies between 1957 and 2005, the incidence of dental caries in young adults decreased, suggesting a decrease in prevalences of dental caries in future generations. However, this tendency was not observed in respondents aged ≥ 40 years. The results suggest adults will experience less dental caries in the near future.     

Dental pulp cells derived from permanent teeth express higher levels of R-cadherin than do deciduous teeth: implications of the correlation between R-cadherin expression and restriction of multipotency in mesenchymal stem cells

ObjectivesThe aim of this study was to characterize the expression status of cadherins in dental pulp-derived mesenchymal progenitor/stem cells from deciduous and permanent teeth, and to determine how cadherins affect the multipotency of the progenitor/stem cells.Materials and methodsWe evaluated and compared the expression status of cadherins in dental pulp-derived cells from deciduous teeth and in cells from permanent teeth by using an array of primers for amplification of RNA encoding human cell adhesion molecules and a real time PCR system. In order to elucidate how cadherins (which are differentially expressed in deciduous and permanent teeth) affect the multipotency of the dental pulp-derived progenitor/stem cells, the ability of the dental pulp cells to differentiate into adipocytes and osteoblasts was evaluated.ResultsR-cadherin was found to be vigorously expressed in the dental pulp cells derived from permanent teeth but not in the dental pulp cells derived from deciduous teeth. N-cadherin was found to be expressed essentially equally in both types of cells. The ability of the dental pulp cells of deciduous teeth to differentiate into adipocytes and osteoblasts was found to be much higher than that of cells obtained from permanent teeth.ConclusionR-cadherin may be a key molecule for providing control over the multipotency of the dental pulp-derived mesenchymal stem cells.     

Site specific mineral composition and microstructure of human supra-gingival dental calculus

Dental calculus has been implicated in the aetiology of several periodontal conditions. Its prevention and removal are therefore desirable clinical goals. While it is known that calculus is very variable in chemical composition, crystallinity and crystallite size little is known about site specific variability within a dentition and between individuals. With this in mind, a study was undertaken to investigate the comparative site specific nature and composition of human dental supra-gingival dental calculus obtained from 66 male patients visiting for their dental check-up using fluorescent X-ray spectroscopy, X-ray diffractometry and Fourier transform infrared spectroscopy. The supra-gingival dental calculus formed on the lingual surfaces of lower anterior teeth and the buccal surfaces of upper molar teeth were classified into four types based on calcium phosphate phases present. There was significant difference in composition of the crystal phase types between lower and upper teeth (p<0.01). There was no significant difference in crystal size between dental calculus on anterior or molar teeth of all samples. The degree of crystallinity of dental calculus formed on the upper molar teeth was higher than that formed on the lower anterior teeth (p<0.01). The CO(3)(2-) contents in dental calculus formed on the lower anterior teeth were higher than on upper molar teeth (p<0.05) which might explain the difference in crystallinity. Magnesium and Si contents and Ca:P ratio on the other hand showed no significant difference between lower and upper teeth. It was concluded that the crystal phases, crystallinity and CO(3)(2-) contents of human dental supra-gingival dental calculus is related to its location in the mouth.     

Beyond冷光美白在治疗氟斑牙和四环素牙中的临床应用

目的 观察Beyond冷光美白剂对氟斑牙和四环素牙患者的漂白效果。方法 对11例不同程度氟斑牙及8例四环素牙患者,采用Beyond冷光美白仪及配套的冷光美白剂进行漂白治疗,分别于漂白前用VITA-3D MASTER比色板（VITA Toothguide-MASTER,以下简称Vita比色板）对牙齿比色并记录,观察漂白效果。结果 使用Beyond冷光美白治疗氟斑牙11例,四环素牙8例,氟斑消失,牙面颜色接近正常。结论 Beyond冷光美白剂对氟斑牙及四环素牙患者的漂白效果可靠。     

Analysis of cathepsin-K activity at tooth and dental implant sites and the potential of this enzyme in reflecting alveolar bone loss

Background: Cathepsin‐K is an enzyme involved in bone metabolism which may make this feature important for both natural teeth and dental implants. The aims of the present study are to comparatively analyze the gingival crevicular fluid (GCF)/peri‐implant sulcus fluid (PISF) cathepsin‐K levels of natural teeth and dental implants, and to assess the potential relationship between this biochemical parameter and alveolar bone loss around natural teeth and dental implants. Methods: Probing depth, bleeding on probing, gingival index, and plaque index clinical parameters were assessed, and GCF/PISF samples were obtained from natural teeth/dental implants presenting with either clinical health, gingivitis/peri‐implant mucositis, or chronic periodontitis/peri‐implantitis. Cathepsin‐K activity levels of 42 GCF samples and 54 PISF samples were determined, and marginal bone loss (MBL) measures were calculated from digitalized standardized intraoral periapical radiographs obtained from natural teeth and dental implants by using cemento‐enamel junction and the actual distance between two consecutive threads of the dental implant as reference points for natural teeth and dental implants, respectively. Results: Comparing the natural teeth group with dental implant group with regard to MBL measure, cathepsin‐K activity, and GCF/PISF volume revealed no significant differences. In both natural teeth and dental implant groups, despite higher MBL measures, cathepsin‐K activity, and GCF/PISF volumes with the presence of inflammation, it was the presence of alveolar bone loss that lead to significantly higher values for these parameters. Conclusion: We suggest cathepsin‐K as a biochemical parameter for monitoring periodontal/peri‐implant alveolar bone loss.     

β-catenin在人恒牙牙髓及牙乳头中的表达

目的:比较人恒牙牙髓、牙乳头组织中β连环蛋白(β-catenin)的mRNA和蛋白的表达情况,探讨β-catenin与牙髓牙本质复合体发育之间的关系。方法:收集48颗因正畸而拔除的健康前磨牙,拔除后立即取出牙髓和牙乳头组织。实验分为3组,第1组为年轻恒牙的牙乳头组织,第2组为年轻恒牙的牙髓组织,第3组为成熟恒牙的牙髓组织。用RT-PCR及Western印迹检测β-catenin的表达,图像分析软件(Meta Morph)对阳性条带进行灰度值的测定。采用SPSS11.0软件包对数据进行两样本t检验。结果:β-catenin在年轻恒牙的牙乳头、牙髓及成熟恒牙的牙髓组织中均有mRNA和蛋白表达,在年轻恒牙牙髓组织中的表达强于在牙乳头组织以及成熟恒牙牙髓组织中的表达(P<0.05)。结论:β-catenin在年轻恒牙和成熟恒牙的牙乳头、牙髓组织中均有不同程度的表达,提示β-catenin在牙髓牙本质复合体发育及牙髓损伤后的修复过程中可能发挥重要作用。     

Can dental epidemiological information be gathered during routine dental examinations by general dental practitioners?

OBJECTIVE: To assess the feasibility of gathering dental epidemiological information by General Dental Practitioners during routine dental examinations. DESIGN AND SAMPLE: Ten General Dental Practitioners (GDPs) and five Community Dental Officers (previously trained as dental examiners for epidemiological purposes) performed dental examinations of the same 10 volunteer adult patients in order to record decayed, missing and filled teeth. RESULTS: Agreement assessed by the kappa statistic showed that both the previously trained dental examiners and the GDPs assessed tooth conditions other than tooth decay consistently. Furthermore, all of the GDPs were within the range of findings of the previously trained dental examiners for missing teeth and total DMFT score. Eight of the 10 GDPs were within the range of findings for the previously trained dental examiners' assessments of which teeth were filled and seven were within the range for decayed teeth. However, the previously trained dental examiners were more consistent in classifying teeth as decayed than the GDPs. CONCLUSION: Obtaining adult oral health data during elective dental consultations in General Dental Practice as a means to gather dental epidemiological information for adults is feasible.     

半导体激光治疗牙本质过敏症牙髓刺激性反应临床及动物实验研究

目的 :探讨激光治疗牙本质过敏症时 ,牙髓组织的刺激性影响。方法 :临床 3 60颗患牙激光治疗 5次 ,观察牙髓刺激性反应发生率。 2 2颗兔牙激光照射后 ,光镜下观察牙髓组织病理改变。结果 :3 60颗患牙发生牙髓刺激性症状共 3颗 ,0 0 0 8%。 2 2颗兔牙照射后即刻或次日拔除的均有牙髓充血 ,或轻度慢性炎症反应 ,第 3天、第 5天拔除的 ,牙髓组织基本恢复正常。结论 :适量的激光照射可产生牙髓充血。但此反应是极轻微的 ,一般不会产生临床症状 ,可以安全使用。     

Background data about the high dental fear scores of Hungarian 8-15-year-old primary school children

Free associations (coupling) of 139 Hungarian primary school children about their teeth was collected. Dental fear (DAS, DFS) and general anxiety scores were measured. Typical dental events (i.e.: loss of deciduous teeth, simple and traumatising dental treatments, tooth fractures) were coupled by the participants in 41.0% of the cases. Functions and importance of the teeth and oral hygiene were described in 20.1% of the cases. Simple, grotesque, or magical stories and tales about teeth were found in 8.6% of the cases. No answer was given in 30.2% of the cases. Highest dental fear and general anxiety scores were found in the group coupled traumatising dental treatment. Traumatising loss of deciduous teeth was caused by the dentist or by the father of the child, and was associated with higher dental fear and general anxiety comparing to simple loss of deciduous teeth. Higher dental fear and general anxiety scores were found in the group coupled functions and importance of the teeth comparing to the group coupled simple, grotesque, or magical stories and tales, or the group giving no answer.     

固定修复重建改善重度成人前牙深覆的研究

目的：总结重建改善成人重度深覆修复方法的综合应用和临床体会。方法：对9例重度前牙深覆伴不同程度牙体牙列缺损的患者,综合应用固定义齿修复,通过适度增高垂直距离的重建方式改善患者的咬合关系。结果：重建以后全部患者牙列形态良好,咬合稳定,咀嚼功能及前牙美观均得到明显改善,经过半年至1年观察,无患者出现颞下颌关节不适主诉。结论：在患者已存在牙体牙列缺损需要修复时,采取适当增加垂直高度的修复性重建方法,可在修复牙体牙列缺损的同时,有效改善成年重度前牙深覆患者的咬合关系、咀嚼功能和美观,是一种较理想的选择。     

Early implant placement for a patient with ectodermal dysplasia: Thirteen years of clinical care

Patients with ectodermal dysplasia have abnormalities of 2 or more structures that originate from the ectoderm. The oral manifestations often include the congenital absence of teeth and malformed teeth. This clinical report describes the interdisciplinary care from childhood through the definitive dental rehabilitation completed at skeletal maturation to replace the missing teeth in a patient with ectodermal dysplasia. Treatment began at 9 years of age with an implant-assisted mandibular overdenture to improve function and replace the missing mandibular teeth. Orthodontic treatment for the consolidation of space, composite resin restorations, and interim removable dental prostheses were provided to improve esthetics and replace the missing maxillary teeth. Skeletal growth was monitored, and orthognathic surgery was performed at the cessation of growth. The definitive rehabilitation consisted of a mandibular fixed dental prosthesis supported by dental implants and a maxillary removable dental prosthesis to restore the patient to esthetics and function.     

Recombination experiments on the odontogenic roles of mouse dental papilla and dental sac tissues in ocular grafts

First molar tooth germs were dissected from mandibles of mouse embryos 16, 17, 18 and 19 days of gestational age. The tooth rudiments were separated into dental papilla, dental sac and enamel organ after enzymic digestion. These embryonic dental tissues were recombined and grown for 4 weeks in anterior chambers of eyes of homologous adult mice. The removal of the dental sac from recombinations of only dental papillae and enamel organs did not significantly alter the proportion of grafts which formed teeth when compared with those grafts which consisted of all 3 dental tissues. Both groups of recombinants formed teeth in 50–80 per cent of the grafts cultured. The dental papilla and dental sac tissues showed the same inductive activity with the enamel organ with the 16-day-old tissues. However, the dental papilla cells maintained their inductive capacity for a longer period. Whereas 70 per cent of the 16-day-old tissue recombinations of dental sac and enamel organ formed teeth, only 15 per cent of the recombinations of older ages of the same tissues formed teeth.     

23例27个粗大根管的根管治疗及修复临床观察

目的 :观察 2 3例 2 7个粗大根管的根管治疗及修复效果并总结治疗经验。方法 :对 2 7个根管未完全发育成形的残根、残冠进行根管治疗及修复 ,随访 2年观察治疗效果。结果 :2 7个粗大根管在根管治疗过程中 ,2 3个牙经化学根管预备后即产生良好的根充效果 ,3个牙仅作机械根管预备而未作化学预备的患牙首次根管治疗失败 ,采用化学预备重新根充效果良好 ,1个牙反复出现瘘管而拔除。自制牙胶尖未发生超充情况。修复后有 7个牙出现根折 ,其余均修复效果良好。结论 :利用化学方法对粗大根管进行预备是必须的 ,采用自制牙胶尖进行根管充填能形成良好的根尖封闭。修复的关键在于尽量保留牙体组织。牙颈部需形成“颈箍” ,肩台必须位于正常牙体组织上。     

不同年龄组和病损牙氟磷含量比的变化

随机采集口腔科门诊拔牙患者的离体牙７０个，按年龄分３组（儿童组、中青年组、老年组）；按病变分３组（正常组、龋齿组、氟斑牙组）。各组牙齿均经１０％甲醛浸泡。清除结石，用优级纯硝酸冷消化处理后，分别采用电化学分析法和分光光度法测定离体牙氟和磷的含量并计算氟磷含量比（Ｆ／Ｐ）。结果表明，中青年组Ｆ／Ｐ值是儿童组的１１８倍，是老年组的１．８倍；而正常组牙齿Ｆ／Ｐ值则是龋齿组的１．６倍，氟斑牙组的１．１倍。     

加热氟化钠对髓腔内温度变化影响的离体牙实验观察

目的:体外实验观察器械加热后放置于不同磨损牙面上所涂的氟化钠糊剂上不同时间髓腔内温度的变化。为临床使用加热氟化钠导入法治疗牙本质过敏症提供实验依据。方法:收集成人完整离体磨牙,根据SmithBGN对牙齿磨损分类,将牙合面制成轻、中、重度磨损,用加热不同时间的金属器械放置在不同磨损程度的牙面上不同时间,观察髓腔内温度变化,以所测温度最高值减测量前基础温度值,所得出髓腔温度上升绝对值进行比较分析。结果:加热器械5和10s,放置牙面不同时间,髓腔温度上升值不同,在最初10~20s内,髓腔温度随器械放置时间延长而上升。在相同时间内,磨损程度越重,髓腔温度上升值越高。结论:器械加热导入氟化钠过程中,器械温度一定时,器械放置时间和牙齿磨损程度是影响髓腔温度的主要因素。     

Evidence-based approach for treatment planning options for the extensively damaged dentition

Restoring the extensively damaged dentition has always been a difficult decision-making process for the dental practitioner. Decisions to restore these teeth were primarily based on the fact that "fixed" teeth are typically better functionally than "removable" teeth and better esthetically than "no" teeth. Prior to dental implants, restoring missing teeth and extensively damaged teeth utilizing traditional therapy such as crown lengthening, root hemisection/amputation, endodontic therapy, apical surgery, post and cores and splinting were the options available to our patients. These teeth typically required the expertise of additional specialist, however their prognosis and success rates were typically guarded at best. Presently, dental implant success rates have been clearly identified and documented in the literature which now questions the survivability and success rates of the traditional mode of therapy for extensively damaged teeth. This paper will attempt to review the dental literature for various traditional modes of therapy for restoring the extensively damaged to provide a consensus of their survivability to help the practitioner to present options and prognosis for their patients.     

即刻种植在严重牙外伤中的应用

牙外伤是口腔急诊中的常见病和多发病,严重的牙外伤常常导致患牙不能保留而需要拔除。以往前牙缺失后采取传统的固定和活动义齿修复或者常规种植修复,通常需要3 ~ 6个月的等待,在这期间患者需要经受缺牙或佩戴活动临时修复体带来的不适。近年来,即刻种植技术迅速发展,不仅能更快地恢复缺失牙的形态和功能,同时能起到尽可能保存原有软硬组织的作用。但临床医生需要意识到,即刻种植在适应证上有较为严格的要求,同时因为牙外伤常发生在前牙美学区,需要考虑相应的美学风险。因此,特别是对于临床经验不足的医生而言,即刻种植手术是一项巨大的挑战。文章对即刻种植在牙外伤中的应用做一简单总结,并结合笔者临床经验分享即刻种植的一些技术要点和病例分析。     

Subsidized dental care improves caries status in male industrial workers

Abstract The association between an employer-provided dental benefit scheme and dental status was studied in male industrial workers in southern Finland in 1994. A total of 325 workers (age 38–65 yrs) with access to subsidized dental care and 174 controls completed a multiple-choice questionnaire followed by clinical examinations. One or more carious teeth was registered in 19% of the subsidized group and 50% of the controls (P<0.001). For subjects with retained roots the proportions were 2% and 15%. respectively (P<0.0()1). Among those with caries the mean number of carious teeth was 2.1 (SD 2.0) in the subsidized group, and 3.2 (SD 3.8) in the control group (P<0.05). The groups did not differ significantly in numbers of teeth or filled teeth. The probability of having one or more carious teeth was negatively associated with access to subsidized dental care, with a recall or check-up as the reason for the last dental visit, and with having had the last dental visit within the past two years. The results showed that the dental benefit scheme resulted in less untreated caries.     

老年人可摘局部义齿修复对基牙的影响

目的:分析研究老年人可摘局部义齿修复后对基牙的影响,探讨其原因及预防措施。方法:对95例牙列缺失后的老年人行冷弯卡环固位式可摘局部义齿修复,记录和比较戴可摘局部义齿后基牙和非基牙的龋坏率和缺失率,用χ2检验分析其结果有无差异,并对影响基牙的原因进行分析。结果:戴用可摘局部义齿5a后,基牙的患龋率(17.38%)显著高于非基牙(7.10%);因牙折、牙周病松动及龋坏无法保留而拔除的基牙缺失率(27.01%)也显著高于非基牙(7.79%)(P<0.01)。结论:冷弯卡环固位可摘局部义齿修复后在一定程度上可增加老年人基牙的患龋率和缺失率。     

陕西陇县出土2000年前人牙齿的形态学研究

目的:了解我国2000年前秦代人牙齿的形态特征,探求牙齿在人类进化过程中的发展趋势及变化。方法:观察记录中国科学院古脊椎动物与古人类研究所保存的59例陕西陇县出土2000年前秦代人的恒牙,共纳入832颗,其中上颌368颗,下颌464颗。分别测量其全长、冠长、根长、冠宽、冠厚、颈宽、颈厚,应用SPSS13.0软件对所有牙位的牙齿测量结果进行统计学分析。结果:报告了这些牙齿的全长、冠长、根长、冠宽、冠厚、颈宽、颈厚7个测量项目的数据。结论:通过对2000年前秦代人牙齿的形态学测量,为人类体质学的研究收集积累数据资料。