低出生体重儿和早产儿乳牙釉质发育缺陷与龋齿易感性的研究

目的从临床和实验研究两方面探讨乳牙釉质发育缺陷与龋齿易感性的关系。方法选择１７６例３～８岁的低出生体重儿和早产儿，分析乳牙釉质发育缺陷与龋齿的相关性；将４颗自然脱落的釉质发育不全乳前牙用于釉质溶解度的研究，比较发育不全部位和正常部位釉粉的溶解度。结果临床研究发现乳牙釉质发育缺陷与龋齿的发生显著相关；乳牙釉质混浊和釉质发育不全分别与龋齿的发生显著相关。溶解度研究发现发育不全的釉质溶解度大，且达到平衡的时间短。结论釉质发育缺陷（釉质发育不全和釉质混浊）增加了牙齿对龋的易感性     

乳牙釉质混浊的偏光特点及其与龋齿易感性的研究

目的 从临床和实验研究两方面探讨乳牙釉质混浊对龋齿的易感性。方法 选择176名3-8岁的低出生体重儿和早产儿，分析乳牙釉质混浊与龋齿的相关性；将5颗自然脱落的釉质混浊乳前牙用于偏光显微镜的研究，发现其组织学特点，并探讨乳牙釉质混浊的发生机制。结果 临床研究发现乳牙釉质混浊与龋齿的发生显著相关；进一步的偏光显微镜研究的发现乳牙釉质混浊为表层下矿化缺陷，且矿化缺陷区域釉柱横纹加重。结论 乳牙釉质混浊因其表层下矿化缺陷增加了牙齿对龋的易感性，乳牙釉质混浊其发生为在牙齿矿化阶段的第三矿化期的中晚期出现全身或局紊乱所致。     

牙菌斑液对牙釉质矿物的饱和程度与龋活动性的关系

为了解菌斑液对牙齿矿物饱和度随糖漱口的变化，以及与龋活动性的关系，作者选择２２例年龄相同的大学生，按龋齿情况，将其分为３组。第１组无龋（无龋组），第２组ＤＭＦＳ大于１０但无活动性龋（普通龋组），第３组ＤＭＦＳ大于１０且有活动性龋（活动性龋组），测定各受试者在静止时、用蔗糖液漱口后３ｍｉｎ和７ｍｉｎ时的菌斑液中有机酸、ｐＨ值、钙离子活度（有效离子浓度）和无机成分的含量，并计算对于釉质矿物的饱和度。结果表明，糖漱口之后菌斑液乳酸浓度升高、ｐＨ值降低、总钙和离子钙浓度增加。活动性龋组的菌斑液在糖漱口后ｐＨ值和饱和度降低的幅度明显大于无龋组和普通龋组。结论：牙菌斑液对牙齿矿物的饱和度是指示个体接受致龋食物后牙齿脱矿倾向的敏感指标。     

Evaluation of vitamin D receptor genetic polymorphisms with dental caries and developmental defects of enamel in Brazilian children

Objectivesto investigate the association between dental caries, developmental defects of enamel (DDE) and genetic polymorphisms in vitamin D receptor (VDR) in Brazilian children.MethodsChildren examination to access the DMFT index was performed according to the World Health Organization's recommendations and the children were classified according their caries experience into ‘No caries experience’ (DMFT = 0), and ‘Caries experience’ (DMFT ≤1), and ‘Low caries experience’ (DMFT ≤3) or ‘High caries experience’ (DMFT≥4) groups. DDE were diagnosed using the modified DDE index based on the Federation Dentaire Internationale (FDI) recommendation. Children were included in the DDE group when presented at least one tooth with a DDE. Genomic DNA was extracted and genetic polymorphisms (rs2228570 and rs739837) were genotyped by TaqMan chemistry and end-point analysis. Chi-square or Fisher exact tests were used to compare genotype and allele distribution among the groups. Epi Info 7 was used to analyze data. The established alpha of this study was 5%.ResultsAmong 157 included children, 19 children (12.1%) were caries free and were in the ‘No caries experience’ group, while 138 children (87.9%) were in the ‘Caries experience’ group. Sixty-seven children (42.7%) were in the ‘Low caries experience’ group while 90 children (57.3%) were in the ‘High caries experience’ group. Five children presented primary dentition, 29 presented mixed dentition and 123 presented permanent dentition. Forty-one (26.1%) children presented at least one tooth with DDE. Caries experience was not associated with DDE (p = 0.71). The polymorphisms rs2228570 and rs739837 were not associated with dental caries, neither DDE (p > 0.05). Allele distributions were also not associated with dental caries, neither DDE (p > 0.05).ConclusionsThe genetic polymorphisms rs2228570 and rs739837 were not associated with dental caries and developmental defects of enamel in Brazilian children.     

Relationship between enamel fluoride concentration and dental caries in a selected population

The relationship between dental caries experience (DMFT) and enamel fluoride concentration (EnF) was determined in 100 freshman dental students aged between 20 and 26 yr. DMFT was determined by clinical examination and supplemented by bitewing radiographs. Biopsies were performed on the maxillary right canine of each student by etching with 1 M perchloric acid for 5 s. A regression analysis of DMFT and EnF and of square root DMFT and 1nEnF indicated that the correlation coefficients were not significant. Students exposed to fluoridated drinking water had significantly lower DMFT and significantly greater EnF than the students reared in areas with non-fluoridated drinking water.     

Genes expressed in dental enamel development are associated with molar-incisor hypomineralization

Genetic disturbances during dental development influence variation of number and shape of the dentition. In this study, we tested if genetic variation in enamel formation genes is associated with molar-incisor hypomineralization (MIH), also taking into consideration caries experience. DNA samples from 163 cases with MIH and 82 unaffected controls from Turkey, and 71 cases with MIH and 89 unaffected controls from Brazil were studied. Eleven markers in five genes [ameloblastin (AMBN), amelogenin (AMELX), enamelin (ENAM), tuftelin (TUFT1), and tuftelin-interacting protein 11 (TFIP11)] were genotyped by the TaqMan method. Chi-square was used to compare allele and genotype frequencies between cases with MIH and controls. In the Brazilian data, distinct caries experience within the MIH group was also tested for association with genetic variation in enamel formation genes. The ENAM rs3796704 marker was associated with MIH in both populations (Brazil: p = 0.03; OR = 0.28; 95% C.I. = 0.06–1.0; Turkey: p = 1.22e?012; OR = 17.36; 95% C.I. = 5.98–56.78). Associations between TFIP11 (p = 0.02), ENAM (p = 0.00001), and AMELX (p = 0.01) could be seen with caries independent of having MIH or genomic DNA copies of Streptococcus mutans detected by real time PCR in the Brazilian sample. Several genes involved in enamel formation appear to contribute to MIH.     

Prevalence of developmental defects of enamel and dental caries in New Zealand children receiving differing fluoride supplementation

A survey of the prevalence of dental caries and developmental enamel defects in 666 New Zealand children aged 9 years and with differing histories of fluoride supplementation was carried out in 1982. In the LF (low fluoride) group 22.8% of children had diffuse white opacities compared with the WF (water fluoridation) group, 36.7%, and the CT (continuous use of fluoride tablets) group 49.4% (P = 0.0018). When the tooth prevalence was determined, the differences were more marked with 4.9% of teeth affected in the LF group and 24.7% in the CT group. Dental caries prevalence in the fluoride history groups displayed an inverse relationship with fluoride supplementation, the LF group had a DMFT of 2.4, the WF group, 1.7 and the CT group, 1.2. The prevalence of both diffuse opacities and of dental caries in the PT group where tablets had been used to 5-6 yr of age was anomalous. The survey confirmed that diffuse opacities occur in children with a low fluoride intake but the prevalence increases in groups of children given fluoride supplements.     

Diagnosis of developmental defects of enamel made from photographs

Photographs offer an opportunity to remotely examine teeth for developmental defects of enamel. However, the flash on the camera can cause burn-out which obscures the surface. Therefore, multiple views may be necessary to overcome this problem. In this study we examined the validity and reliability of diagnosis of enamel defects made from photographs. A series of five intra-oral photographs (central, right lateral, left lateral, superior and inferior views) at 1 : 1 magnification were taken for 125 Chinese children aged 12 to 13 years. The maxillary incisor teeth of these children were examined both clinically and photographically for enamel defects which, if present, were recorded using the modified FDI (DDE) Index. One hundred sets of slides were then randomly selected from the subjects and were viewed by six professional and two lay observers for enamel defects. The slide sets of five views and three views (central and two lateral views) were studied separately. The Kappa coefficients which were in the range of “substantial” to “total agreement” (κ = 0.73–1.00) at the tooth level for agreement between the clinical and the five-view photographic assessments on indicated that photographs were a reliable alternative to the clinical examination to detect the presence of enamel defects. No apparent significant differences were noted between the assessments of the two slide sets. These findings suggest that a series of three slides is adequate to study enamel defects for the four maxillary incisors.     

Do enamel and dentine caries at 5 years of age predict caries development in newly erupted teeth? A prospective longitudinal study

Abstract

Objective: To explore caries development in children from 5 to 12?years of age, and to study whether enamel caries and dentine caries at 5?years of age could predict caries prevalence at 12?years of age, controlled for child characteristics.

Methods: The study included 3282 children examined at 5 and 12?years of age. Data were collected by clinical examination and questionnaire. Enamel and dentine caries were registered at surface level. Data were tested by t-test and analysed by bi- and multivariate logistic regression. The study was ethically approved.

Results: In 5-year-olds, 15% of the children had dentine caries experience and 21% had enamel caries. In 12-year-olds, 32% had dentine caries experience and 47% had enamel caries. Children with dentine caries experience at 5?years of age had at 12?years of age developed more surfaces with enamel caries (mean 2.8, SD 4.2) and dentine caries experience (mean 1.8, SD 2.5) than other children (p?<?.05). Dentine caries experience at 12?years of age was associated with having only enamel caries (OR 1.6, CI 1.2–2.0) and dentine caries experience (OR 3.2, CI 2.6–3.9) at 5?years of age. Family status and parental education were related to caries development.

Conclusion: Children with caries in primary teeth continued to be caries risk children during the mixed dentition period. In addition to dentine caries experience, enamel caries in primary teeth was a predictor for caries development in young permanent teeth and may be used to improve the caries risk assessment.     

Prevalence of dental fear and its relationship with primary dental caries in 7-year-old-children

BackgroundChild's dental fear has been reported as one of the reasons that increase, aggravate dental diseases and facilitate other oral diseases. This study is aimed to describe the type and prevalence of dental fear and to assess the relationship between cavities of primary teeth and dental fear in 7-year-old children at Phulam Primary School, Hanoi.MethodsThe sample comprised of 132 children aged 7 years. The questionnaire examined the profile of participants and assessed their dental fear using the Children's Fear Survey Schedule-Dental Subscale (CFSS-DS). Children have “dental fear” when the total CFSS-DS score is greater than or equal to 38. By contrast, those without dental fear gain the total point which is less than 38. After completing the questionnaire, a dental examination was undertaken according to the International Caries Detection and Assessment System (ICDAS).ResultsThe prevalence of dental fear was 34.85%. Fear scores were highest for “Dentist drilling” (2.92 ± 1.47) and “Injections” (2.87 ± 1.53). In the univariate analysis, the odds of girls having dental fear were approximately equal to boys (OR = 0.98, 95% CI = ?0.75-0.70). The odds of only children having dental fear were 1.6 times higher than others, but there were not significant. Dental fear was found to be no associated to sex, birth order and primary dental caries (p > 0.05).ConclusionOur findings demonstrated the status of 7-year-old children's dental fear at Phulam primary school, and found that primary dental caries had no correlation with child dental fear score.     

Genetic influences on dental enamel that impact caries differ between the primary and permanent dentitions

Clinically, primary and permanent teeth are distinct anatomically and the presentation of caries lesions differs between the two dentitions. Hence, the possibility exists that genetic contributions to tooth formation of the two dentitions are different. The purpose of this study was to test the hypothesis that genetic associations with an artificial caries model will not be the same between primary and permanent dentitions. Enamel samples from primary and permanent teeth were tested for microhardness at baseline, after carious lesion creation, and after fluoride application to verify association with genetic variants of selected genes. Associations were found between genetic variants of ameloblastin, amelogenin, enamelin, tuftelin, tuftelin interactive protein 11, and matrix metallopeptidase 20 and enamel from permanent teeth but not with enamel from primary teeth. In conclusion, our data continue to support that genetic variation may impact enamel development and consequently individual caries susceptibility. These effects may be distinct between primary and permanent dentitions.     

Prevalence of developmental enamel defects of the first permanent molars among school children in Western Australia

BACKGROUND: The prevalence of enamel defects in the first permanent molars among children has been reported to be high and may be on the increase, particularly in the European countries. Little information is available on the prevalence of enamel defects in the first permanent molars among children in Australia. The aim of this study was to describe the prevalence of enamel defects in the first permanent molars among school children in Western Australia. METHODS: Informed consent was obtained from parents of children attending pre-primary schools within an administrative area of the School Dental Service of Western Australia in metropolitan Perth to participate in the study in 2005. Parents completed a questionnaire about the mother's health status during pregnancy, and their child's health status for the first three years. Participating children were examined during 2006 and 2007 by one examiner. Teeth were classified on the type and extent of enamel defects using the modified DDE index, and deciduous tooth caries experience of molars and canines was recorded using the WHO criteria. RESULTS: Parents of 634 children out of the eligible 1135 (56 per cent participation) completed the questionnaire. Five hundred and eleven children with at least one erupted first permanent molar were examined (mean age 7.1 years, SD 0.5). Of the first permanent molars, 42 per cent upper right; 37 per cent upper left; 47 per cent lower left; and 45 per cent lower right were without enamel defects. White diffuse opacities were the predominant enamel defects found with 46 per cent upper right; 47 per cent upper left; 40 per cent lower left and 41 per cent lower right molars affected. Demarcated opacities alone or in association with other defects affected 11 per cent upper right; 14 per cent upper left; 10 per cent lower left and 9 per cent lower right molars. At the individual level, 71 per cent had permanent molars with enamel defects; 47 per cent with white diffuse opacities and 22 per cent with demarcated opacities. CONCLUSIONS: Prevalence of enamel defects among this school population is high. Majority of defects were white diffuse opacities and the prevalence of demarcated opacities is at the high end of that reported for some European countries. Possible risk factors for enamel defects remains to be tested.     

Prevalence and distribution of enamel defects and dental caries in a region with different concentrations of fluoride in drinking water in Sri Lanka

AIMS: To assess the prevalence and distribution of developmental defects of enamel and caries in 14-year-old children who had been lifetime residents in a region with different concentrations of fluoride in drinking water in Sri Lanka. DESIGN: A cross-sectional survey. SETTING: Uda Walawe--a rural area in southern Sri Lanka where fluoride concentration in ground water is reported to be within the range of 0.05-6.10 mg/l. METHOD: A total of 518 children from six representative schools from this area were examined for developmental defects of enamel and dental caries using the modified DDE index and WHO criteria. The present analysis is limited to 486 children from whom drinking water samples were collected. RESULTS: Based on the fluoride concentration of the drinking water source the children were categorised into four groups: <0.3, 0.31-0.49, 0.5-0.7 and >0.7 mg/l. The prevalence of enamel defects ranged from 29-57% whilst 27-55% of children were affected by diffuse opacities in the four groups. Of the ten teeth examined, between 1.6-3.6 teeth per child were affected by enamel defects. Maxillary first premolars were the most commonly affected by diffuse opacities followed by the maxillary canines. Caries prevalence varied between 18-25% whilst the mean DMFT and DMFS values ranged from 0.29-0.54 and 0.45-0.67 respectively. Occlusal surfaces were the most affected by caries. CONCLUSIONS: The wide differences observed in the prevalence and severity of enamel defects indicate that there are variations in individual response to high fluoride levels in drinking water. It also demonstrates the need to ascertain the factors that could contribute to the prevalence and severity of enamel defects other than high fluoride levels in drinking water.     

3--6岁儿童龋齿患病情况调查及相关因素分析

目的了解呼和浩特市3～6岁儿童龋齿发病情况及影响龋齿的相关因素,为学龄前儿童防治龋病提供科学依据。方法采取整群抽样方法,随机抽取6所幼儿园的1358名3-6岁儿童进行口腔龋齿检查,并对其口腔卫生、生活习惯等进行问卷调查。使用Epidata3．0软件录入问卷,SPSS15．0进行统计分析。结果1358名儿童乳牙龋患率为51．3％,6岁组儿童龋患率较高为68．3％,龋均为2．77,不同性别龋齿患病率无统计学差异（P〉0．5）。经多因素分析,发现年龄、喂养方式、早晚坚持刷牙、甜食摄入及家长对口腔健康的重视程度与儿童龋患有着密切关系。结论本地区学龄前儿童龋齿患病率较高,应加大健康教育宣传力度,家长定期检查口腔卫生问题,促使儿童尽早刷牙,控制儿童龋齿患病率。     

乳酸杆菌在儿童龋病中作用的研究进展

乳酸杆菌（LB）是一种产酸、耐酸性细菌,能高效代谢糖类产酸,使牙体组织脱矿,LB是龋病的主要致病菌,在龋病的发病中起到至关重要的作用,与龋病的发展密切相关,而儿童龋病又有其特点。本文对国内外儿童（年龄<12岁）龋病的流行病学、龋病的菌群分布、致病LB基因型及其与其他致病菌的相互作用在龋病发病中的作用等方面的研究进展作一综述。     

早产儿乳牙釉质发育缺陷及患龋状况的临床研究

目的研究早产儿乳牙釉质发育缺陷及龋病的发病率,并探讨两者的相关关系。方法选取3～7岁早产儿及足月出生儿两组各173名,进行乳牙釉质发育缺陷及患龋情况的调查统计和数据对比分析。结果早产儿组釉质发育缺陷(DDE)的患病率(63.58%)明显高于正常出生组DDE的患病率(34.10%),其患病率男女性别间无明显差异。DDE好发于上颌切牙。早产儿组的患龋率(69.36%)与正常出生组的患龋率(71.68%)无明显差异。结论早产儿的乳牙釉质发育缺陷率较高,做好早产儿的口腔保健及父母的口腔健康知识教育是非常重要的。     

釉质龋的非破坏性治疗方法

釉质龋是一种非细胞反应性病变,可导致牙齿硬组织的破坏.传统治疗釉质龋的方法往往会损害到正常的牙体组织,因此目前非破坏性修复釉质龋的新方法成为了研究的热点和难点,本文就非破坏性治疗釉质龋的2种方法——再矿化和仿生矿化法的最新进展作一综述.     

釉质龋的非破坏性治疗方法

釉质龋是一种非细胞反应性病变,可导致牙齿硬组织的破坏。传统治疗釉质龋的方法往往会损害到正常的牙体组织,因此目前非破坏性修复釉质龋的新方法成为了研究的热点和难点,本文就非破坏性治疗釉质龋的2种方法——再矿化和仿生矿化法的最新进展作一综述。