两种探针探诊牛牙人工早期龋对釉质的影响

目的:比较5 号尖探针和CPI探针探诊牛牙人工早期龋对釉质的影响.方法:采用体外酸蚀法构建牛牙人工早期龋的离体模型;通过定性、定量研究比较2 种探针探诊牛牙人工早期龋对釉质的影响.结果:扫描电镜发现,5 号尖探针探诊牛牙人工早期龋形成的探孔窄而深,CPI探针探诊牛牙人工早期龋形成的探孔宽而浅. CPI探针探诊对釉质产生的应变能大于5 号尖探针产生的应变能,两者之间的差异有统计学意义(Z＝-2.021,P=0.043),但由于二者的应变能值是在同一等级范围内,所以2 种探针对牛牙人工早期龋釉质的影响差异无实际意义.结论:5 号尖探针探诊牛牙人工早期龋对釉质的破坏并没有明显大于CPI探针.建议龋齿的流行病学调查和临床检查仍可以使用5 号尖探针,应避免采用较重的力去探诊,减少对釉质结构的潜在影响.     

Evaluation of the effectiveness of laser fluorescence in monitoring in vitro remineralization of incipient caries lesions in primary teeth

The purpose of this investigation was to examine the effectiveness of laser fluorescence for monitoring in vitro remineralization of caries lesions. Seventeen natural enamel lesions in primary molars were each cut into two parts. One part was exposed, at room temperature, to a remineralizing solution (experimental) and the other part to water (control) for 28 days. Laser fluorescence readings were taken at the beginning of the experiment and during the experiment. At the end of the experiment, lesion depth in the experimental halves was significantly less than in the control halves (p < 0.01), suggesting that remineralization had occurred. However, the laser fluorescence readings showed no statistically significant changes during the experiment, either in the experimental or control halves. We conclude that laser fluorescence was not able to detect in vitro remineralization of natural incipient caries lesions of primary teeth.     

The Distribution of Root Caries in Community-dwelling Elders in New England

An in-home examination of a probability sample of elders aged 70 and older living in the six New England states was conducted to estimate the prevalence and extent of root caries. Oral examinations were conducted by the visual-tactile method using a portable lamp, explorer, and a mouth mirror. Fifty-two percent of the study participants showed root caries experience and 22 percent had untreated root caries. In contrast to previous studies, this analysis showed that buccal root surfaces were no more likely than proximal surfaces to be affected by root caries. Logistic regression analysis showed that gingival recession and number of teeth were positively associated with root caries, while better oral hygiene maintenance and regular dental visits were negatively associated with root caries lesions (all factors: P <.05). The prevalence of root caries was found to increase with higher numbers of teeth except for a minority subgroup— i.e., those who retained 25 or more teeth. This study provides much-needed data on prevalence and extent of root caries in a probability sample of the oldest old in an entire region of the United States.     

Early detection of white spot lesions with digital camera and remineralization therapy

BACKGROUND: In this paper, the characteristics of the early stage of dental caries are discussed and the methods we used to treat the early stage of dental caries to increase the number of caries-free patients are presented. Studies from in vitro to in situ experiments and a clinical study were carried out to support clinical remineralization therapy. METHODS AND RESULTS: To clarify the effect of time for remineralization, the degree of remineralization was assessed at 2 days, 6 days, and 10 days after 2-day demineralization in 0.01 M/L lactic acid buffer (pH 4.0 at 37 degrees ). The remineralization solution contained 3.0 mM/L Ca, 1.8 mM/L P, and 3 ppm fluoride adjusted to pH 7.0. A 10-day continuous remineralization with a 3 ppm fluoride resulted in a high fluoride concentration. To evaluate mineral loss from sound tooth structure and white spot lesions, thin sections (about 90 microm) including white spots (WS) were prepared and exposed to oral conditions for 2 weeks continuously. The mineral loss from sound tooth structure was found to be twice that from WS. In another experiment during the remineralization period, enamel samples were immersed in three different bicarbonate solutions; 0.5, 5.0 and 50 mM/L for 30 minutes, two times per day. Both the bicarbonate and fluoride applied groups showed higher improvement in acid resistance and the amount of remaining mineral was almost two times higher than the controls (p < 0.01). In a clinical study we demonstrated remineralization in patients who followed professional mechanical tooth cleaning and fluoride prophylaxis paste. Using this regime, in patients with deciduous caries present at baseline, over 80 per cent of permanent teeth were caries free at the age of 12 years. In these studies the digital camera with CasMaTCH and an image analysis system showed several advantages for monitoring in de- and remineralization. CONCLUSIONS: White spot lesions, rather than intact tooth surfaces, can be mineralized through the daily clinical procedures described in this paper.     

Longitudinal study of caries and cariogenic bacteria in an elderly disabled population

A 2-yr longitudinal study was conducted among elderly disabled residents of a longterm care facility. Each of the 50 subjects examined at the beginning of the study had a mean of 14 teeth, with a mean of 6 carious and 6 restored teeth, per person. Most of the subjects had very poor oral hygiene, and 26 of them had dental plaque that produced cultures of mutans streptococci and lactobacilli in excess of 10(5) CFU/ml. At the end of the first year, 40 subjects were examined again and, apart from a decrease in the mean number of carious root lesions per person, there was very little change in their dental or microbial status. Although only 18 subjects were available at the end of the second year, they presented with fewer carious lesions after 2 yr. The reduction in caries appeared to result from the remineralization of tooth structure, but new lesions did appear in 33% of the 1-yr group, and in 78% of the 2-yr group. This dynamic environment around the teeth produced a mean net incidence of one lesion in the first year, and three lesions over 2 yr. There was a significant (P less than 0.05) association between large (greater than 10(5) CFU/ml) numbers of mutans streptococci and the development of new lesions, but there was no association between the dental status of the subjects and the dental treatment they received. Overall, the results indicate that caries is not rampant in this population.     

Effects of dental probing on occlusal surfaces--a scanning electron microscopy evaluation

The aim of this clinical-morphological study was to investigate the effects of dental probing on occlusal surfaces by scanning electron microscopy (SEM). Twenty sound occlusal surfaces of third molars and 20 teeth with initial carious lesions of 17- to 26-year-old patients (n = 18) were involved. Ten molars of each group were probed with a sharp dental probe (No. 23) before extraction; the other molars served as negative controls. After extraction of the teeth, the crowns were separated and prepared for the SEM study. Probing-related surface defects, enlargements and break-offs of occlusal pits and fissures were observed on all occlusal surfaces with initial carious lesions and on 2 sound surfaces, respectively. No traumatic defects whatsoever were visible on unprobed occlusal surfaces. This investigation confirms findings of light-microscopic studies that using a sharp dental probe for occlusal caries detection causes enamel defects. Therefore, dental probing should be considered as an inappropriate procedure and should be replaced by a meticulous visual inspection. Critical views of tactile caries detection methods with a sharp dental probe as a diagnostic tool seem to be inevitable in undergraduate and postgraduate dental education programmes.     

氯化钠溶液对人牙根面牙本质早期龋再矿化作用的影响

目的：探讨单纯用氯化钠（NaCl)溶液处理人牙根面牙本质早期龋后，提高根面早期龋再矿化作用的可行性，方法：在人牙根面上形成早期人工龋，将标本分组，分别用0．5mol/L,NaCl溶液和0．5mol/L EDTA二钠盐溶液浸泡后，用再矿化液处理，扫描电镜下观察比较早期龋矿化前牙根表面形态及矿化后牙根表面矿物盐沉积情况，显微X线照像及其图像分析比较矿化后矿物含量的不同。结果：人牙根面早期龋表面用NaCl溶液浸泡前后无明显改变，早期龋用EDTA二钠盐溶液浸泡后表面见大量牙本质小管开放，再矿化后，前者比后者表层明显增厚，表层阻射度明显增强。结论：用NaCl溶液处理人牙根面早期龋以后，再矿化效果明显增强，NaCl溶液对早期龋表面无不良影响。     

根龋封闭治疗后的细菌学和病理学研究

目的:研究根龋封闭治疗后,发生的龋病静止效应。方法:采用封闭剂治疗活动根龋前(基线),封闭后6个月的龋性牙本质样本进行细菌培养计数;选择活动根龋封闭1年后需拔除的患牙制作牙本质切片用作病理观察。结果:17例活动性根龋牙封闭治疗后半年,涂膜下存活细菌总量及特异致龋菌数量均大幅度降低(P<0.0001);病理学观察发现活动根龋封闭1年后,龋病静止,涂膜下龋性牙本质表层有再矿化区带形成。结论:封闭剂治疗根龋,有望把活动件龋损转化为静止龋,这可能为老年根龋防治提供新的途径。     

Root lesions in a group of 50–60 year-old Germans related to clinical and social factors

From a preventive point of view collection of data concerning carious and non-carious cervical tooth defects is definitely important. Consequently, the prevalence and distribution of different root lesions were studied and correlated with behavioral and biological factors in 50- to 60-year-old German individuals (n=298). Additionally, the data were correlated with characteristics concerning oral health and known risk factors such as gender, educational level, and presence of plaque. An interview included questions on sociodemographic and socioeconomic characteristics, dental and general health status, and various behavioral parameters. During clinical examination data concerning coronal and root lesions, restorations, probing depth, gingival bleeding, and dental plaque were obtained. The participants represented a social middle class population with a high awareness of dental health. Obviously, for the participants, known risk factors for root decay such as gender, educational level and plaque index were of minor importance. Factors correlating with root caries were: (a) number of missing teeth, (b) probing depth, (c) smoking habit, (d) regular dental attendance and (e) the reason for the last dental treatment. Additionally, the prevalence of non cariogenic lesions, primarily resulting from increased but wrongly performed oral self care, seems gradually to relieve carious root destruction. Received: 22 June 1999 / Accepted: 24 August 1999     

The effects of medium chain fatty acids and fluoride on fissure caries in Wistar rats

This work was to compare the degree of caries protection provided by fatty acids with chain lengths of 9-12 carbons and to assess the anti-caries potential of a fluoride-fatty acid mixture. Male Wistar rats were weaned at 21 days, maintained on a standard laboratory diet for 7 days and then provided with a cariogenic, 45% sucrose diet for 34 days. This regimen produced a very reproducible degree of fissure caries and the inclusion of 1% powdered potassium nonanoate or decanoate in the diet gave large and significant reductions in total and advanced lesions. Decanoate was significantly more inhibitory towards advanced lesions than was nonanoate. In contrast, 1% potassium laurate was considerably less effective under these conditions. Caries protection with a mixture of 0.25% decanoate and 76 parts/10(6) fluoride was found to be cumulative rather than synergistic. It is suggested that the optimal effect obtained with decanoate was due to a favourable combination of the surfactant and wetting properties of this molecule at the low pH values found in fissure dental plaque. It is also suggested that fluoride and decanoate acted in an independent manner to enhance remineralization of early lesions and to inhibit the acidogenic flora, respectively.     

3种无氟儿童牙膏对乳牙早期釉质龋再矿化作用的体外研究

目的 探究3种市售无氟儿童牙膏即生物活性玻璃儿童牙膏、双黄连儿童牙膏、木糖醇儿童牙膏对乳牙早期釉质龋的再矿化作用。方法 应用离体乳牙制备人工龋模型50例,随机分为5组：活性玻璃组、双黄连组、木糖醇组、NaF组、去离子水组。在体外进行pH循环后,测量各组乳牙的表面显微硬度,并结合偏光显微镜对乳牙的釉质龋损进行形态学观察。结果 活性玻璃组能显著提高乳牙早期釉质龋再矿化后的表面显微硬度（P<0.05）,但其提高的程度不如NaF组（P<0.05）,双黄连组、木糖醇组和去离子水组未能提高再矿化后的显微硬度（P<0.05）。偏光显微镜下,活性玻璃组与NaF组再矿化后乳牙表层釉质的脱矿深度明显变浅。结论 生物活性玻璃儿童牙膏能有效促进乳牙早期釉质龋再矿化,但其再矿化能力小于含氟牙膏,双黄连儿童牙膏和木糖醇儿童牙膏在本次实验中未能体现出再矿化能力。     

五倍子提取液促进实验性根面龋再矿化的研究

目的：研究五倍子提取液促进实验性根面龋再矿化的作用。方法：采用化学法制备根面龋模型，用500g／L五倍子提取液，380g／L氟化氨银液，20g／L氟化钠液和去离子水处理后放人再矿化液中7d，用扫描电镜和显微放射成像术分别观测其表面形态、龋损深度和脱矿量。结果：再矿化前，扫描电镜观察五倍子与氟化氨银处理后牙骨质龋表面形成不规则短钝状突起；氟化钠液组形成大小不一的散在大球状突起，可见一些腔隙存在；去离子水组大量分布夏伯氏纤维。再矿化后，五倍子液和氟化氨银液组表面结构更加致密，均匀，呈小斑块，条索状；氟化钠液组表面也出现条索状结构，但仍有孔隙或腔隙存在；去离子水组表面出现蜂窝状结构。显微放射成像术分析各药物处理组均能明显促进实验性根面龋的再矿化，与去离子水相比相差显著（P〈0．05），其中氟化氨银液组效果最好，五倍子液和氟化钠液相当。结论：五倍子具有抑制实验性根面龋进展，促进其再矿化的作用。     

Proportions of Streptococcus mutans, lactobacilli and Actinomyces spp in root surface plaque

Abstract – The incidence of Streptococcus mutans, lactobacilli and Actinomyces was examined in root surface dental plaque from 24 subjects with root surface caries and in 24 subjects with exposed root surfaces as a consequence of periodontitis but without root surface caries. Plaque was collected from the most posterior teeth in each quadrant: in the caries group from carious lesions and in the periodontitis group from buccal root surfaces. There were significantly higher proportions of S. mutans and lactobacilli in dental plaque samples taken from subjects suffering from root surface caries than in samples from subjects without root surface caries. The level of the group A. viscosus/naeslundii in the periodontitis group was higher than that found in the root surface caries group, but the difference was not statistically significant.     

臭氧辅助微创去龋法治疗老年人根面龋的临床研究

目的：评价臭氧辅助微创去龋法治疗老年人根面龋的有效性和安全性.方法：门诊老年龋齿患者59例,同一病人不同龋齿随机分为臭氧组、微创治疗组和对照组例,分别采用臭氧辅助微创法、微创和传统去龋法,比较病人的感受和治疗效果.结果：臭氧辅助微创组病人痛苦小,安全,治疗效果与传统法无统计学差异.结论：臭氧辅助微创法治疗老年人根面龋安全、无痛、有效.     

In vitro remineralization effects of grape seed extract on artificial root caries

Grape seed extract (GSE) contains proanthocyanidins (PA), which has been reported to strengthen collagen-based tissues by increasing collagen cross-links. We used an in vitro pH-cycling model to evaluate the effect of GSE on the remineralization of artificial root caries. Sound human teeth fragments obtained from the cervical portion of the root were stored in a demineralization solution for 96 h at 37 degrees C to induce artificial root caries lesions. The fragments were then divided into three treatment groups including: 6.5% GSE, 1,000 ppm fluoride (NaF), and a control (no treatment). The demineralized samples were pH-cycled through treatment solutions, acidic buffer and neutral buffer for 8 days at 6 cycles per day. The samples were subsequently evaluated using a microhardness tester, polarized light microscopy (PLM) and confocal laser scanning microscopy (CLSM). Data were analyzed using ANOVA and Fisher's tests (p<0.05). GSE and fluoride significantly increased the microhardness of the lesions (p<0.05) when compared to a control group. PLM data revealed a significantly thicker mineral precipitation band on the surface layer of the GSE-treated lesions when compared to the other groups (p>0.05), which was confirmed by CLSM. We concluded that grape seed extract positively affects the demineralization and/or remineralization processes of artificial root caries lesions, most likely through a different mechanism than that of fluoride. Grape seed extract may be a promising natural agent for non-invasive root caries therapy.     

电化学人工龋模型的形成方法

1990年黄力子提出了“龋病发病机理的生物电化学理论”,认为龋病的发生和发展主要是一种电化学腐蚀过程。本研究为验证此理论,将离体牙置于电解池中以观察对比电解池阴、阳极的氧化还原反应对牙齿脱矿的不同影响。结果表明电解池阳极的氧化反应能促进牙齿脱矿,使接触阳极的牙齿开窗区形成深达牙本质的类龋洞;电解池阴极的还原反应能够抑制牙齿脱矿,接触阴极的牙齿开窗区表面完整。电化学人工龋模型的成功为“龋病发病机理的生物电化学理论”提供了直接的实验证据。     

Consequences of Success: Do More Teeth Translate into More Disease and Utilization?

Objectives : Increased tooth retention coupled with increased numbers of older adults means that the actual number of teeth at risk to dental disease will increase sharply. Whether this increase in the number of teeth will translate into more disease and utilization in unknown. The purpose of this study was to test this "more teeth, therefore more dental disease" theory using cross-sectional data. Methods : In-home personal interview and oral examination data were obtained on a probability sample of elders aged 70 years and older living in the six New England states using the Medicare beneficiary list as a sampling frame. Data on dental utilization, number of teeth, dental caries, and periodontal disease were included in the current analysis. Results : Analysis of variance on subjects with 1–10 (Group 1), 11–24 (Group 2), and 25–32 (Group 3) teeth show that the extent of bleeding on probing, pocket depth, and loss of attachment all increase as numbers of teeth increase. Similarly, a greater number of restored coronal and root surfaces were found in Group 3 relative to the other two groups. Mean numbers of decayed and filled coronal surfaces were 8.4 in Group 1,33.0 in Group 2, and 50.3 in Group 3. In contrast, unrestored coronal and root surfaces were significantly higher in Group 1 (mean root DS=1.3) than Group 3 (mean root DS=0.3). Utilization patterns of those with successful aging dentitions (Group 3) show that they are visiting dentists more frequently than the compromised group (Group 1). Conclusion : These cross-sectional data obtained from a probability sample of New England elders show that subjects who retained higher numbers of teeth have more periodontal disease and dental caries experience, and visit the dentist more frequently.     

龋病患牙牙周健康状况调查分析

目的：检查龋病患牙的牙周健康状况,探讨龋病对牙周健康状况的影响。方法：在武汉大学口腔医学院牙体牙髓科和牙周黏膜科就诊的患者中,选择一侧牙有龋,而对侧同名牙无龋的牙齿86对,每对牙齿依次检查牙体龋坏情况（包括冠龋和根龋）及牙周状况（包括探诊深度、探诊出血、牙石指数、牙龈退缩程度、松动度）,并进行统计学分析,研究龋病患牙的牙周健康状况。结果：86对牙齿比较结果显示,有龋组的牙周探诊深度、牙石指数、牙龈退缩程度、松动度均显著高于无龋组（P〈0.05）。对有龋组牙仅有冠龋的71对牙齿做比较,结果显示有龋组患牙的牙周探诊深度、牙石指数、牙龈退缩程度均高于无龋组,有显著性差异,且探诊深度、牙石指数有非常显著的差异（P〈0.01）。对有龋组中既有冠龋又有根龋的15对牙齿牙周情况做比较,结果显示有龋组牙龈退缩、松动度均高于无龋组且有显著性差异（P〈0.05）。结论：在同一口腔环境中龋病的发生和牙周炎症程度呈正相关,两者的微生态联系和相互影响有待深入的研究。     

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.     

氟纳米羟基磷灰石对早期根面龋再矿化效果的实验研究

目的:通过实验研究氟纳米羟基磷灰石对早期根面龋的再矿化效果,并与纳米羟基磷灰石、氟化泡沫和氟化钠溶液的再矿化效果进行比较。方法:制备人工早期根面龋模型41个,使用扫描电镜观察脱矿后的根面的表面形态及用数显显微硬度计测量脱矿后根面的显微硬度。将40个根面龋模型随机分为5组:空白对照组、氟纳米羟基磷灰石组、纳米羟基磷灰石组、氟化泡沫组和氟化钠溶液组。每组使用其相应的试剂处理,经7 d pH循环及20d再矿化处理,于扫描电镜观察和显微硬度计测量。统计采用单因素方差分析并作LSD-t检验,实验前后采用单样本t检验。结果:氟纳米羟基磷灰石组扫描电镜观察根表面有大量晶粒沉积且平滑,其硬度值与脱矿后和其他组硬度值比较,有统计学意义(P<0.05)。结论:氟纳米羟基磷灰石对早期根面龋有较好的再矿化效果。