Influence of examiner's clinical experience on the reproducibility and accuracy of radiographic examination in detecting occlusal caries

The aim of this in vitro study was to assess the influence of varying examiner's clinical experience on the reproducibility and accuracy of radiographic examination for occlusal caries detection. Standardized bitewing radiographs were obtained from 166 permanent molars. Radiographic examination was performed by final-year dental students from two universities (A, n=5; B, n=5) and by dentists with 5 to 7 years of experience who work in two different countries (C, n=5; D, n=5). All examinations were repeated after 1-week interval. The teeth were histologically prepared and assessed for caries extension. For intraexaminer reproducibility, the unweighted kappa values were: A (0.11-0.40), B (0.12-0.33), C (0.47-0.58), and D (0.42-0.71). Interexaminer reproducibility statistics were computed based on means +/- SD of unweighted kappa values: A (0.07 +/- 0.05), B (0.12 +/- 0.09), C (0.24 +/- 0.08), and D (0.33 +/- 0.10). Sensitivity, specificity, and accuracy were calculated at D(1) and D(3) thresholds and compared by performing McNemar test (p=0.05). D(1) sensitivity ranged between 0.29 and 0.75 and specificity between 0.24 and 0.85. D(3) specificity was moderate to high (between 0.62 and 0.95) for all groups, with statistically significant difference between the dentists groups (C and D). Sensitivity was low to moderate (between 0.21 and 0.57) with statistically significant difference for groups B and D. Accuracy was similar for all groups (0.55). Spearman's correlations were: A (0.12), B (0.24), C (0.30), and D (0.38). In conclusion, the reproducibility of radiographic examination was influenced by the examiner's clinical experience, training, and dental education as well as the accuracy in detecting occlusal caries.

Exposed collagen in aged resin-dentin bonds produced on sound and caries-affected dentin in the presence of chlorhexidine

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of Psidium cattleianum leaf extract on enamel demineralisation and dental biofilm composition in situ

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Evaluation of partially dentate patients' knowledge about caries and periodontal disease

Objective: This investigation evaluated the knowledge of dental caries and periodontal disease among removable partial denture (RPD) wearers.Method: A total of 127 partially dentate patients participated in this observational study. A structured questionnaire, which included eight questions referring to knowledge about aetiology and prevention of dental caries and periodontal disease, was developed in the local language (Portuguese) and used to collect the data of all the partial denture wearers. A descriptive analysis of data was performed by means of drafting tables.Results: The results demonstrated that 68.5% of patients interviewed had previously received information about oral health care. With regard to bacterial plaque, it was observed that only 34.6% reported having knowledge of this. Whereas, in relation to caries, 76.4% of the interviewees replied that they knew the meaning of this. Nevertheless, 28.3% referred to caries as a whole in the teeth, 16.5% as bad teeth and 9.4% bacteria/creatures on the teeth. Only 17.3% of the partially edentulous patients evaluated were shown to know what disease of the gingiva was.Conclusion: By means of the methodology applied, it could be concluded that the patients who wore RPDs presented deficient knowledge with regard to the prevention, aetiology and development of dental caries and periodontal disease.

Effect of light-curing units on microleakage under dental composite resins

The aim of this study was to determine the effect of two light-curing units (QTH and LED) on microleakage of Class II composite resin restorations with dentin cavosurface margins. Twenty extracted mandibular first premolars, free of caries and fractures were prepared two vertical slot cavities in the occluso-mesial and -destal surfaces (2 mm buccal-lingually, 2 mm proximal-axially and cervical limit in enamel) and divided into 4 equal groups (n = 8): GI and GII: packable posterior composite light-activated with LED and QTH, respectively; GIII and GIV: micro-hybrid composite resin light-activated with LED and QTH, respectively. The composite resins were applied following the manufacturer's instructions. After 24 h of water storage specimens were subjected to thermocycling for a total of 500 cycles at 5 and 55A degrees C and the teeth were then sealed with impermeable material. Teeth were immersed in 0.5% Basic fuchsin during 24 h at room temperature, and zero to three levels of penetration score were attributed. The Mann-Whitney and Kruskal-Wallis tests showed significant statistically similar (P > 0.05) from GI to GII and GIII to GIV, which the GII (2.750) had the highest mean scores and the GIII and GIV (0.875) had lowest mean scores. The use of different light-curing units has no influence on marginal integrity of Class II composite resin restorations and the proprieties of composite resins are important to reduce the microleakage.

Comparative scanning electron microscopic study of the effect of different dental conditioners on dentin micromorphology

This study evaluated comparatively by scanning electron microscopy (SEM) the effect of different dental conditioners on dentin micromorphology, when used according to the same protocol. Forty dentin sticks were obtained from 20 caries-free third human molars and were assigned to 4 groups corresponding to 3 conditioners (phosphoric acid 37%, Clearfil SE Bond and iBond) and an untreated control group. After application of the conditioners, the specimens were immersed in 50% ethanol solution during 10 s, chemically fixed and dehydrated to prepare them to SEM analysis. In the control group, dentin surface was completely covered by smear layer and all dentinal tubules were occluded. In the phosphoric acid-etched group, dentin surface was completely clean and presented exposed dentinal tubule openings; this was the only group in which the tubules exhibited the funnel-shaped aspect. In the groups conditioned with Clearfil SE Bond primer and iBond, which are less acidic than phosphoric acid, tubule openings were occluded or partially occluded, though smear layer removal was observed. SE Bond was more efficient in removing the smear layer than iBond. In the Clearfil SE Bond group, the cuff-like aspect of peritubular dentin was more evident. It may be concluded all tested conditioners were able to change dentin morphology. However, it cannot be stated that the agent aggressiveness was the only cause of the micromorphological alterations because a single morphological pattern was not established for each group, but rather an association of different aspects, according to the aggressiveness of the tested conditioner.

Efficacy of dip slide test for mutans streptococci in caries risk assessment

The aim of this study was to evaluate the efficacy of a dip slide test for mutans streptococci in caries risk assessment, when the microbiological results were compared to well-defined clinical criteria (DCC) for caries risk, clinically measured through high and low caries activity. Eighty-one volunteers from the 6(th) to 8(th) grades from public schools of Piracicaba, São Paulo, Brazil, were evaluated for dental caries. All free smooth surfaces were evaluated to check whether or not there were white spots. Based on the subjects' caries experience, a calibrated clinician divided them into groups of high and low caries activity. The subjects were submitted to a salivary test (CARITEST SM (R)) from the same batch number. Kappa statistics (kappa) were applied to verify the reproducibility of the simplified test, checked through interexaminer agreement when the results were classified by independent and blind means. The microbiological results were validated according to expressions of sensitivity and specificity. A moderate agreement was verified as the results were classified according to 6 scores (kappa =0.55), and the agreement was substantial when the results were classified according to high and low microbiological count (kappa =0.78). The sensitivity and specificity values were 0.59 and 0.85, respectively, showing that the test was more specific than sensitive, and could thus better identify the low caries risk subjects.

Occlusal caries prevention in high and low risk schoolchildren. A clinical trial

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Caries risk tests and salivary levels of immunoglobulins to Streptococcus mutans and Candida albicans in mouthbreathing syndrome patients

The aim of this study was to compare microbiological and salivary variables possibly related to caries risk in treated and untreated mouthbreathing syndrome (MBS) children and control children. Thirty control children, 30 mouthbreathers and 25 treated mouthbreathers were studied for the numbers of lactobacilli, mutans streptococci and yeasts in their saliva. Snyder's test, salivary flow and buffering capacity were also evaluated. Levels of immunoglobulins to Candida albicans and Streptococcus mutans in the saliva were quantified using ELISA. Considering the results obtained for the microbiological and salivary caries risk tests, no significant differences were observed among the proportions of patients with small/negative and high/moderate caries risk in the studied groups. The level of IgG to S. mutans was significantly higher in the treated MBS group in relation to MBS patients. on the other hand, the median anti-S. mutans IgM level was lower in the treated MBS patients than in the other groups. For the studied anti-Candida immunoglobulins, IgM level was significantly lower in the treated MBS group than in the other groups. No differences were observed for anti-S. mutans and anti-Candida IgA levels among the groups. The findings suggest that mouthbreathing cannot be considered a risk factor for dental caries. Copyright (C) 2003 S. KargerAG, Basel.

Dental fluorosis: Exposure, prevention and management

Dental fluorosis is a developmental disturbance of dental enamel, caused by successive exposures to high concentrations of fluoride during tooth development, leading to enamel with lower mineral content and increased porosity. The severity of dental fluorosis depends on when and for how long the overexposure to fluoride occurs, the individual response, weight, degree of physical activity, nutritional factors and bone growth. The risk period for esthetic changes in permanent teeth is between 20 and 30 months of age. The recommended level for daily fluoride intake is 0.05 - 0.07 mg F/Kg/day, which is considered of great help in preventing dental caries, acting in remineralization. A daily intake above this safe level leads to an increased risk of dental fluorosis. Currently recommended procedures for diagnosis of fluorosis should discriminate between symmetrical and asymmetrical and/or discrete patterns of opaque defects. Fluorosis can be prevented by having an adequate knowledge of the fluoride sources, knowing how to manage this issue and therefore, avoid overexposure.

Ability of different restorative materials to prevent in situ secondary caries: analysis by polarized light-microscopy and energy-dispersive X-ray

Secondary caries is the main cause of direct restoration replacement. The purpose of this study was to analyze enamel adjacent to different restorative materials after in situ cariogenic challenge using polarized-light microscopy (PLM), scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDS). Twelve volunteers, with a low level of dental plaque, a low level of mutans streptococci, and normal salivary flow, wore removable palatal acrylic appliances containing enamel specimens restored with Z250 composite, Freedom composite, Fuji IX glass-ionomer cement, or Vitremer resin-modified glass-ionomer for 14 days. Volunteers dripped one drop of 20% sucrose solution (n = 10) or distilled water (control group) onto each specimen 8 times per day. Specimens were removed from the appliances and submitted to PLM for examination of the lesion area (in mm(2)), followed by dehydration, gold-sputtering, and submission to SEM and EDS. The calcium (Ca) and phosphorus (P) contents were evaluated in weight per cent (%wt). Differences were found between Z250 and Vitremer, and between Z250 and FujiIX, when analyzed using PLM. Energy-dispersive X-ray analysis results showed differences between the studied materials regarding Ca %wt. In conclusion, enamel adjacent to glass-ionomer cement presented a higher Ca %wt, but this material did not completely prevent enamel secondary caries under in situ cariogenic challenge.

Effect of caries preventive measures directed to expectant mothers on caries experience in their children

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Changes in caries prevalence in 7-12-year-old children from Araraquara, São Paulo, Brazil: 1989-1995

O objetivo deste estudo foi comparar a prevalência de cárie em crianças de sete a 12 anos em Araraquara, São Paulo, Brasil, em 1989 e 1995. Foi utilizada amostragem sistemática para selecionar crianças de escolas públicas. Examinadores treinados realizaram levantamentos epidemiológicos, utilizando o índice CPOD e os critérios de diagnóstico da OMS. em todas as idades, houve aumento da porcentagem de crianças livres de cárie na dentição permanente (de 29% em 1989 para 51% em 1995). Para crianças aos 12 anos de idade, foram observados índices CPOD de 3,8 em 1989 e de 2,6 em 1995. Detectaram-se também reduções nas porcentagens de crianças classificadas nas seguintes categorias do CPOD: um a três (de 40% em 1989 para 31% em 1995); quatro a seis (de 26,6% em 1989 para 16,5% em 1995) e sete ou mais (de 4,4% em 1989 para 1,5% em 1995). A meta da OMS/FDI para o ano 2000, de que aos 12 anos os indivíduos apresentem em média índice CPOD menor ou igual a três, foi atingida pelos escolares em estudo. Esforços devem ser empreendidos para que haja redução da porcentagem de crianças com experiência de cárie e sejam alcançadas as metas de saúde bucal da OMS/FDI para o ano 2010.

Efeito da prática de alimentação infantil e de fatores associados sobre a ocorrência da cárie dental em pré-escolares de 18 a 48 meses

Este estudo foi realizado objetivando estudar o efeito das práticas de alimentação infantil e de fatores associados sobre a ocorrência de cárie dental. Para isso, determinou-se o ceo-d e o ceo-s em 156 crianças de 18 a 48 meses e foi aplicado às mães um questionário incluindo perguntas sobre a ocupação do pai, nível educacional da mãe, higiene bucal, época de erupção do dente e sobre práticas de alimentação infantil. Os dados obtidos foram analisados através dos testes X2 e Mann-Whitney U. A média do ceo-s foi 3,4 com 40% das crianças livres de cáries, sendo que 36 e 24% tinham um ceo-d maior que 0 e 4, respectivamente. Notou-se que 72% das crianças eram alimentadas ao seio, 17% apenas com mamadeira e 10% pelos dois meios. Das crianças alimentadas apenas com mamadeira 70% apresentaram cárie. A cárie de mamadeira foi observada em 20% das crianças, sendo que 77% destas tinham sido alimentadas por mais de 12 meses. As crianças, cujos pais eram profissionais com terceiro grau de escolaridade, tiveram significativamente menos cárie do que aquelas de pais com nível técnico ou pais operários. A prevalência de cárie na faixa etária estudada foi relativamente alta. As crianças com cárie de mamadeira tenderam a manter seus hábitos de aleitamento por mais de 12 meses, sendo que o uso de mamadeira açucarada estava presente em 100% dos casos.