Strontium content in hard tissues of milk teeth with and without caries

By the method of atomic absorption flame spectrophotometry the strontium level was determined in the hard tissues of milk teeth with and without caries. The studied material comprised 163 milk teeth, including 81 with caries. All teeth were obtained from children of either sex living in Lublin. The material was divided into three age groups: up to 6 years, 6-10 years, and over 10 years. The obtained results were subjected to statistical analysis using an IMP85 m computer. It was found age and sex had no significant effect on the strontium level in the hard tissues of healthy milk teeth. However, a significant correlation was observed between strontium level and caries presence. Milk teeth with caries contained less strontium than carietic teeth.     

Analysis of correlations between the content of various elements in hard tissues of milk teeth with and without caries

Using the method of atomic absorption spectrometry the levels of calcium, magnesium, zinc, iron, strontium, nickel, manganese, copper were determined in the hard tissues of milk teeth with and without caries and the interrelations between these elements were analysed The obtained results were subjected to statistical analysis with an IMP 85 m computer. In the present study the analysis of the interrelations between elements was based on correlations and regression analyses. Many statistically significant interrelations were revealed between Mn and Fe, Mn and Zn, Mn and Cu, Mn and Ni, Fe and Zn, Fe and Cu, Fe and Ni, Zn and Cu, Zn and Ni. A decrease of the correlation coefficients was noted in carietic teeth. For the highly correlated elements equations of simple regression were calculated. A significant correlations was noted between caries and the levels of Mg, Zn, Fe, Sr, Ni, Mn, Cu in the hard tissues in milk teeth. The carietic milk teeth contained less Mg, Fe, Sr, Ni, Mn and Cu and much more Zn as compared to teeth without caries.     

Ultrastructural pattern of enamel in initial caries

In beginning caries of particular interest are destructive changes in the enamel layers just below the surface. The studied material comprised about twenty enamel blocks obtained from 10 teeth with carietic spots removed for orthodontic reasons in children aged 12-14 years. The aim of the study was assessment of the initial enamel damage under electron microscope. In all electronograms of the enamel involved by the carietic spot various grades of demineralization of the enamel below its surface were seen. The changes in initial caries seemed well delineated from the remaining healthy enamel, although within the carietic focus demineralization was observed from very slight widening of the area around the prisms to massive destruction of prism structure. The changes in the carietic spot under electron microscope showed a wide variety of patterns of destruction of enamel prisms, although clinically the surface of the enamel involved by beginning caries was small and not damaged.     

Clinical pattern of secondary dental caries in relation to tissue defect class and type of filling material

The purpose of the study was assessment of the development of secondary caries in relation to filling type in various classes of carietic dental tissue defects. The study was carried out in 320 patients aged 16 to 55 years and 3884 teeth were examined. Out of this material 2423 teeth were filled: with amalgam--853, with silica cement--1197, with composites--373. Secondary caries was found in 1341 teeth (56.34%). In teeth filled with amalgam in classes I and II of carietic defect in women secondary caries was noted in 27.26% and 47.73% of cases respectively. In case of composite filling secondary caries was found in 72.12% and 81.82% of fillings. In class III of carietic defects in women with fillings with composite materials secondary caries developed in 48.8%, and after filling with silica preparations in 55%. In class IV secondary caries was present at 45% of composite fillings and 77.78% of silica cement fillings. In class V secondary caries was found at 11.42% of amalgam fillings and 36.67% of composite fillings, and in 45% at silica cement fillings. Similar values were found in men.     

Age and content of certain mineral components in permanent teeth

The chemical composition of the teeth is determined during its development, however, in the postdevelopmental period changes of inorganic components are possible, which have an important effect on the morphology, structure and chemical composition of teeth. Using the method of X-ray fluorescence the levels of Ca, P, Cl, S, K and Zn were determined in hard tissues of 218 permanent non-carietic teeth from all dental groups. The correlation between these various elements in the teeth and the age of the subjects, whose teeth were taken for the investigations, was expressed with the correlation coefficient r of Pearson. The significance of the correlation was analysed using Students t test. In case of significant correlation equations of regression were determined for predicting the expected value of the level of a given element in teeth for a given age. No significant differences were noted in the levels of Ca and P in relation to age. The levels of S, K and Zn rose with age, while the chloride content was decreasing.     

Evaluation of caries prevalence in children and adolescents in Zabrze subjected to planned stomatological care

In a group of 923 children aged 8 to 15 years (475 girls and 448 boys) caries was found in 80.61%. The intensity of the carietic process (DMF) was for the whole group 3.08 teeth. The study demonstrated increasing prevalence of caries with age. The intensit and the prevalence of caries were greater in girls than in boys. The analysis of the components of the DMF index showed a considerably large proportion of teeth with active caries with a low proportion of filled and removed teeth. The mean D index in the whole group was 2.09, in girls it was 2.22, in boys 1.93. The mean number of filled teeth was low: 0.91 for all children, 1.09 for girls, and 0.72 for boys. In the studied population the characteristic age, that is reaching of equal DMF values for the maxilla and mandible, was at the end of the 12th year of life and earlier in girls. Moreover, it was found that the intensity of caries was greatest in molar teeth and lowest in canine teeth. This was due, among others, to the condition of sixth teeth which was unsatisfactory. The mean DMF of the first permanent molars was 2.28 for the whole group, 2.46 for girls and 2.09 (teeth) for boys.     

Migration of metallic ions from screwposts into dentin and surrounding tissues.

Previous investigations have shown htat corrosion and other electrochemical processes occure when different alloys or metals are found together in the same mouth. In the present report, when teeth were restored using non-noble metallic posts, the metals diffused out to surrounding hard and soft connective tissues. The material consisted of extracted teeth with screw posts and surrounding discolored connective tissues. The screwposts had been cemented to the teeth 3--10 years earlier. The distribution of metal ions was determined by means of energy-dispersive X-ray microanalysis. Copper and zinc were found in both hard and soft tissues. Relatively high concentrations of copper ions were identified in areas of the teeth with blue-green discolorations. Zinc ions were detected in the dentin; they most probably originated from the screwposts and the cement, but zinc is also found in normal human dentin. Copper, zinc, silver and iron were found in the dark discolorations of the gingiva adjacent to the extracted teeth.     

Migration of metallic ions from screwposts into dentin and surrounding tissues

ABSTRACT – Previous investigations have shown that corrosion and other electrochemical processes occur when different alloys or metals are found together in the same mouth. In the present report, when teeth were restored using non-noble metallic posts, the metals diffused out to surrounding hard and soft connective tissues. The material consisted of extracted teeth with screwposts and surrounding discolored connective tissues. The screwposts had been cemented to the teeth 3–10 years earlier. The distribution of metal ions was determined by means of energy-dispersive X-ray microanalysis. Copper and zinc were found in both hard and soft tissues. Relatively high concentrations of copper ions were identified in areas of the teeth with blue-green discolorations. Zinc ions were detected in the dentin; they most probably originated from the screwposts and the cement, but zinc is also found in normal human dendn. Copper, zinc, silver and iron were found in the dark discolorations of the gingiva adjacent to the extracted teeth.     

DMFT, dmft and treatment requirements of schoolchildren in Asturias, Spain

An epidemiological survey was carried out in 1992 to study the dental health status of schoolchildren aged 6, 9 and 12 in Asturias, Spain. It focused on the caries prevalence, dmtf, DMFT, restoration indices and dental treatment needs of this population. A representative sample of 1839 subjects, randomly selected and proportionally assigned by age group (6, 9 and 12) with the classroom as the sample unit, was examined. Analysis of the data showed that in 6-year-old children the caries prevalence in primary teeth was 45.8%. The mean caries in-dices were 2.10 dmft and 0.25 DMFT. At 9 years old the prevalence of caries in primary teeth was 62.8% and in the permanent teeth 49.1%. The mean level of caries was 2.38 dmft and 1.50 DMFT. At 12 years old the caries prevalence in permanent teeth was 71% and in first molars 64.2%. The mean caries experienced was 3.30 DMFT. In all groups the D-component constituted the major part of the caries index. The results for girls were higher than for boys in almost all age groups. Surface fillings were the treatment most required in all age groups.     

Effect of fluoridated milk on caries: 3-year results

The effect of fluoridated milk consumption has been investigated in a follow-up study of 269 children aged 3-9 years. Children consumed 200 ml of milk daily, fluoridated in the groups 3-5 years with 0.4 mg F-, and in those aged 6-9 years with 0.75 mg F-, for 300 days yearly. The caries data were analyzed with special regard to changes in the DMF values of the permanent first molars, the yearly examination data of the corresponding age groups compared and correlated with the length of fluoridated milk consumption. Statistical analysis of the permanent first molar data showed significant negative correlation between DMF means and length of fluoridated milk consumption in children 5-6 years old at the time of evaluation. The caries reduction after 3 years was 74% and statistically significant (P less than 0.001). In children 7-9 years old the caries reduction of the permanent first molars was less, and statistically not significant. A slight reduction of DMFS mean values in the front teeth of this group could be observed.     

Progression of approximal caries in relation to iatrogenic preparation damage.

The aim of the present study was to evaluate the effect of iatrogenic preparation damage on the need for operative caries treatment of approximal surfaces, adjacent to Class II amalgam restorations. The material was collected by 77 dentists from the Public Dental Child Health Service in Denmark. It consisted of die-stone models of 187 first-time Class II preparations, adjacent to 190 unfilled approximal surfaces of 58 primary and 132 permanent teeth. The cavity preparations were performed in children between 4 and 17 years of age. They were all filled with amalgam. Information about operative treatment and exfoliation or extraction of the preparation teeth and the adjacent teeth during the following seven years was obtained from the patients' records. Stereomicroscopic examination of the models revealed preparation damage on 64% of the unfilled approximal surfaces in primary teeth and on 69% of the corresponding test surfaces in permanent teeth. During the observation period, operative treatment was performed on 10% of the undamaged test surfaces in primary teeth and on 35% of the damaged ones (p less than 0.05). The corresponding figures for test surfaces in permanent teeth were 6% and 15% (p less than 0.05). It is concluded that iatrogenic preparation damage is a frequent side-effect of operative intervention with approximal caries lesions, and represents a dental health problem, since the damage increases caries progression and the perceived need for restorative therapy of the adjacent teeth.     

Dental caries in adult and elderly Chinese

This paper reports on a study of dental caries conducted among 1744 urban and rural Chinese (from 20 to 80 years old), who were selected by means of a systematic stratified sampling procedure. The prevalence of one or more decayed or filled teeth ranged from 48 to 90% in urban residents, and from 51 to 97% in rural residents, depending on age. The mean number of decayed or filled teeth ranged from 1.2 (+/- 1.9) among 20-29-year-olds, to 6.2 (+/- 5.5) among 70+-year-olds, and was highest among rural residents. Among 20-29-year-olds, the main components of the DFT were enamel lesions and fillings. Among 30-49-year-olds, the DFT consisted mainly of enamel lesions and filled teeth, as well as teeth with lesions involving the pulpal tissues. In subjects over the age of 50 years, lesions involving pulpal tissues were the predominant type, followed by root-surface lesions. In subjects below the age of 50 years, most of the caries experience derived from coronal surfaces, particularly occlusal surfaces. Root-surface caries was predominantly a feature of persons aged 50 years and above. Despite a large number of surfaces being at risk of root-surface caries, less than 10% of the surfaces were so affected. Although cross-sectional in nature, these data indicate that when the oral hygiene standards are poor, caries lesions continue to develop and progress throughout life. With age, dental caries becomes a substantial oral health problem in this population of adult and elderly Chinese, despite the availability of some dental services.     

Quantitative and qualitative characteristics of the bacterial flora of saliva and dental plaque in artificially fed children

Stomatological and bacteriological studies were carried out in 66 children aged 1-5 years divided into two groups: I--without caries, II--with carietic lesions typical of the so called "bottle caries", that is with carietic defects on the vestibular surfaces of upper incisors and on masticating surfaces of first molars. No differences of qualitative character were found in the bacterial flora of the saliva and the dental plaques in children with "bottle caries" in relation to those without caries. A significant correlation was noted between the quantity of S. mutans and Lactobacillus in the saliva or dental plaque and the intensity of caries. These results confirm the suggestions of other authors that Str. mutans plays an important role in caries and that it is the prevailing species among acid-producing flora in children with bottle caries.     

Durability of tunnel restorations in general practice: a three-year multicenter study

Twelve dentists, clinically experienced and familiar with the tunnel technique, placed 374 tunnel restora tions in permanent teeth. Mean age of the patients was 19.1 years (range 10-74). The filling material used was a glass cermet cement, Ketac Silver. After 1, 2 and 3 years the teeth were controlled by the dentists. The bitewing radiographs from baseline, 1, 2 and 3 years were also analyzed by 2 of the authors, independently. The baseline radiographs showed technical defects in 6% and indicated remaining dentin caries in 8% of the restorations. After 3 years, 305 restorations were accessible for examination. The cumulative replacement rate was 20%. The main reasons for replacement were marginal ridge fracture (14%) and dentin caries (3%). The number of restorations showing untreated progressive caries increased during the study. After 3 years, untreated dentin caries was seen in 28 cases (11%) and almost half of the left enamel lesions showed progression.     

Durability of tunnel restorations in general practice: a three-year multicenter study

Twelve dentists, clinically experienced and familiar with the tunnel technique, placed 374 tunnel restorations in permanent teeth. Mean age of the patients was 19.1 years (range 10-74). The filling material used was a glass cermet cement, Ketac Silver. After 1, 2 and 3 years the teeth were controlled by the dentists. The bitewing radiographs from baseline, 1, 2 and 3 years were also analyzed by 2 of the authors, independently. The baseline radiographs showed technical defects in 6% and indicated remaining dentin caries in 8% of the restorations. After 3 years, 305 restorations were accessible for examination. The cumulative replacement rate was 20%. The main reasons for replacement were marginal ridge fracture (14%) and dentin caries (3%). The number of restorations showing untreated progressive caries increased during the study. After 3 years, untreated dentin caries was seen in 28 cases (11%) and almost half of the left enamel lesions showed progression.     

Oral findings and microbiological evaluation in a case of triple-X syndrome

We present a case of a triple-X syndrome in a Japanese girl who was treated from 5Y9M to 14Y6M of age at the Pedodontic Clinic of Osaka University Dental Hospital. At the first examination, multiple dental caries were identified, and a pulpectomy and extraction of the affected teeth were carried out. There were no congenitally absent teeth, including third molars, though the development of permanent teeth was approximately 2 years behind chronological age. At 14Y6M, a PCR analysis of 10 putative periodontopathic bacteria was performed, and all 10 species were found in saliva samples. At the same time, an oral examination revealed that the gingival tissues were highly inflamed with an extremely large amount of calculus, suggesting a risk for the early onset of periodontitis.     

2005年广东省成年人恒牙冠龋病抽样调查报告

目的 了解广东省35～44岁、 65～74岁人群恒牙龋病状况,为广东省口腔卫生保健工作提供信息支持.方法 采用多阶段分层等容量随机抽样的方法,抽取广东省35～44岁、 65～74岁城乡常住人口各720人,男女各半.按照《第三次全国口腔健康流行病学调查方案》中临床检查牙列状况的检查方法和标准,使用CPI探针检查全口恒牙牙冠龋病情况.数据采用SAS 8.1软件统计,计算出患龋率、龋均.结果 35～44岁组恒牙患龋率为63.89%、龋均为1.99;患龋率和龋均均为女性高于男性,农村高于城市. 65～74岁组患龋率为74.17%、龋均为3.37;患龋率和龋均均为农村高于城市.结论 广东省成年人群龋病患病率较高,人群大部分龋齿未得到治疗.     

Caries in primary teeth at 5 and 10 years of age: a longitudinal study.

AIM: This was to explore the caries development in the primary dentition in children aged 5 and later when they were 10, with an emphasis on the caries increment according to type of teeth and surfaces. METHODS: The study was a prospective, longitudinal survey where the children were examined in 1993 when they were 5 years of age (n=217) and re-examined in 1998 when they were 10 (n=186). Caries was examined clinically and with radiographs by calibrated dentists based on a caries diagnostic grading system from 0 to 5. Primary incisors were excluded from the registrations at 10 years of age, while teeth exfoliating during the period were included, based on notes from the dental records. RESULTS: Intra- and inter-examiner reliability ranged from kappa 0.62 to 0.90. Dmfs at 5 years was 5.4 (incisors included) and 7.4 at 10 years (incisors excluded, other exfoliated teeth included). The mean caries increment during the age period showed no significant difference between children with and without caries at 5 years of age. Molar-approximal lesions dominated the increment, and when such lesions were diagnosed at 5 years of age, there was an increased risk for more severe caries (dentine lesions) during the period. CONCLUSION: The caries increment in the primary dentition is considerable for the majority of children during the age period 5-10 years. Even if a risk assessment based on the prevalence of approximal caries at 5 years of age may be useful for deciding individual recall intervals, the results of this study seem to suggest frequent check-ups are needed for the whole population.     

Influence of posteruptive age of enamel on its susceptibility to artificial caries

Epidemiologic studies and caries experiments with animals have suggested that caries susceptibility of teeth decreases with age. Observations on the changes in the dental tissues and their environment with age have pointed out that a process commonly referred to as 'posteruptive maturation' of the dental enamel may be responsible. To test this assumption 10 unerupted third molars and 56 erupted human premolar teeth of various posteruptive ages were subjected for 130 days to an acid gel for caries-like lesion formation in vitro. Sections of the teeth were examined with polarized light and 'contour maps' were drawn with the approximate porosity of the lesions. The results were: unerupted = 833 microns (+/- 261); erupted of posteruptive age 0-3 years = 561 microns (+/- 150), 4-10 years = 470 microns (+/- 136), 11-30 years = 459 microns (+/- 192) and over 30 years = 297 microns (+/- 89). These findings show a decrease in the susceptibility of enamel to artificial caries with increasing age, which was especially marked at and shortly after eruption. This may be explained by a completion of mineralization of the outer enamel at about eruption, by a maturation process of the outer enamel posteruptively and by a reduction in the permeability of enamel occurring through to old age. The fluoride content of the mid-coronal buccal surface enamel under study was found to decrease posteruptively with age, therefore not accounting for the decreasing caries susceptibility.     

Predictors of tooth loss over 10 years in adult and elderly Chinese

Abstract This study describes the incidence of tooth loss over a 10–year period in a population of rural Chinese, initially aged between 20 and 80 years. Among the 587 persons who participated in a baseline examination in 1984, 440 persons were available for a follow-up study in 1994. A total of 31 persons, mainly aged 50+ years at baseline, had become completely edentulous. Between 45% and 96% of the persons lost at least one tooth, and the average number of teeth lost ranged between 1.0 and 7.2. The distribution of the number of teeth lost was skew, indicating that a minor group of subjects had a substantially higher risk of tooth loss than the majority. Logistic regression analysis identified six significant predictors of tooth loss among those who remained dentate: age, a high number of teeth with dentinal caries lesions, a high number of teeth with caries lesions of any type, presence of teeth with attachment loss 7 mm, presence of mobile teeth, and a low percentage of sites with subgingival calculus deposits. At the subject level, caries variables and periodontal disease variables seemed equally important predictors of the incidence of tooth loss over 10 years, but at the tooth level caries was a predominant cause of tooth loss in all age groups.