Geographic information systems (GIS) in assessing dental health

The present study investigated the distribution profile of dental caries and its association with areas of social deprivation at the individual and contextual level. The cluster sample consisted of 1,002 12-year-old schoolchildren from Piracicaba, SP, Brazil. The DMFT Index was used for dental caries and the Care Index was used to determine access to dental services. On the individual level, variables were associated with a better oral status. On the contextual level, areas were not associated with oral status. However, maps enabled determining that the central districts have better social and oral conditions than the deprived outlying districts.

Unconjugated hyperbilirubinemia and early childhood caries in a diverse group of neonates

We evaluated if the development of early childhood caries is associated with the severity of unconjugated hyperbilirubinemia during the first 2 weeks after birth. We performed a retrospective case-control study of children less than 6 years of age seen for comprehensive dental examination by pediatric dentists years following a hospital stay in the neonatal intensive care unit. Exclusion criteria included genetic disorders, cleft palate, direct hyperbilirubinemia, and missing information on jaundice. Children with early childhood caries were compared with those without dental caries for a panel of perinatal and neonatal clinical variables. Seventy-six children met study criteria. Of 76 children, 42 children had early childhood caries, while 34 children had healthy primary dentitions. Among clinical variables, only race and peak total serum bilirubin concentration differed significantly between the two groups on bivariate analysis. On logistic regression, peak total serum bilirubin concentration was significantly associated with early childhood caries (adjusted odds ratio 1.17, 95% confidence interval 1.04 to 1.32). Neonatal unconjugated hyperbilirubinemia may be associated with early childhood caries in children.

Dentists' use of caries risk assessment in children: findings from the Dental Practice-Based Research Network

This study surveyed Dental Practice-Based Research Network (DPBRN) member dentists (from four regions in the U.S. and Scandinavia) who perform restorative dentistry in their practices. The survey asked a range of questions about caries risk assessment in patients aged 6 to 18. Among respondents, 73% of dentists reported performing caries risk assessment among these patients, while 14% assessed caries risk by using a special form. Regions in which most dentists were in a private practice model were the least likely to perform caries risk assessment, while regions where most dentists practiced in a large group practice model were the most likely to use a special form for caries risk assessment. Recent graduates from dental school were more likely to use a caries risk assessment compared to older graduates. Current oral hygiene, decreased salivary flow, and the presence of active caries were rated as the most important caries factors. Some differences by region were also evident for the risk factor ratings. These results suggest that not all community dentists assess caries risk. The results of this study also indicate considerable variability in dentists' views concerning the importance of specific caries risk factors in treatment planning and weak evidence that caries risk assessment is driving clinical practice when preventive treatment recommendations are being considered.

Effects of mixology courses and blood lead levels on dental caries among students

OBJECTIVE

Dental caries can be affected by alcohol consumption. Alcohol consumption also increases blood lead levels (BLLs) in humans and BLLs have been correlated with caries. Culinary students participate in mixology courses on either an elective or a mandatory basis. Therefore, we conducted this study to elucidate the effects of mixology courses and elevated BLLs on dental caries among students.

METHODS

This study had a cross-sectional design. We recruited first-year at one hospitality college and one university in southern Taiwan in September 2004. We applied a questionnaire, collected a blood specimen and performed a dental caries examination for each student. The subjects comprised 133 students who had ever participated in a mixology course (≥2 credits) during high school (exposure group) and 160 who had not participated in such a course (control group).

RESULTS

Compared with the control group, the exposure group had a higher prevalence of a DMFT index ≥ 0 (92.5% versus 81.2%, P = 0.005), a higher DMFT index [5.59 ± 3.53 (mean ± SD) versus 4.21 ± 3.64 teeth, P ≤ 0.001], and a higher BLL (3.12 ± 1.02 versus 2.67 ± 0.83 μg/dl, P = ≤ 0.001). After adjustment for potential confounders, dental caries was significantly associated with participation in a mixology course.

CONCLUSIONS

  Alcohol exposure associated with participation in a mixology course may have an effect on caries in students. These findings suggest that occupational safety and health education should be applied to students participating in mixology courses.

Millennium development goals and oral health in cities in Southern Brazil

OBJECTIVES

To investigate social determinants of oral health, analysing the occurrence of associations between millennium development goals (MDG) indicators and oral health (OH) indicators.

METHODS

An ecological study was performed in two distinct phases. In Phase 1, MDG indicators and related covariates were obtained from the demographic census of the Brazilian Institute of Geography and Statistics, the Ministry of Health database and the 2000 Human Development Atlas, making up the whole set of independent variables. Principal component analysis was carried out for the independent variables showing the correlations among the variables comprising the main components, and generating a synthetic index allowing the performance of the cities to be known with regard to the MDG (MDG index). In Phase 2, the DMFT index (mean number of decay, missing or filled permanent teeth) and the CF index (prevalence of caries-free individuals), in 12 years old were obtained from the epidemiological survey undertaken in 2002-2003, in 49 cities in southern Brazil, and were analysed in relation to the MDG index using Spearman's correlation.

RESULTS

  A statistically significant correlation was found for the DMFT and CF indices, respectively, with: the MDG index (R(2)=0.49 and 0.48; P = 0.00); the socioeconomic status of the population (R(2)= 0.12 and 0.12; P = 0.02); the socioenvironmental characteristics (R(2)=0.41 and 0.46; P= 0.00).

CONCLUSIONS

  The MDG synthetic index of the cities analysed and the respective components relating to their socioeconomic and socioenvironmental status demonstrated a positive correlation with OH indicators. As such, intersectoral public policies based on population strategies that act on social determinants of general and oral health need to be integrated so as to impact on the MDG and OH outcomes.

In vitro near-infrared imaging of occlusal dental caries using germanium enhanced CMOS camera

The high transparency of dental enamel in the near-infrared (NIR) at 1310-nm can be exploited for imaging dental caries without the use of ionizing radiation. The objective of this study was to determine whether the lesion contrast derived from NIR transillumination can be used to estimate lesion severity. Another aim was to compare the performance of a new Ge enhanced complementary metal-oxide-semiconductor (CMOS) based NIR imaging camera with the InGaAs focal plane array (FPA). Extracted human teeth (n=52) with natural occlusal caries were imaged with both cameras at 1310-nm and the image contrast between sound and carious regions was calculated. After NIR imaging, teeth were sectioned and examined using more established methods, namely polarized light microscopy (PLM) and transverse microradiography (TMR) to calculate lesion severity. Lesions were then classified into 4 categories according to the lesion severity. Lesion contrast increased significantly with lesion severity for both cameras (p<0.05). The Ge enhanced CMOS camera equipped with the larger array and smaller pixels yielded higher contrast values compared with the smaller InGaAs FPA (p<0.01). Results demonstrate that NIR lesion contrast can be used to estimate lesion severity.

Dental caries risk indicators among Australian Aboriginal young adults

OBJECTIVES

To determine dental caries risk indicators among a birth cohort of Australian Aboriginal young adults (n=442).

METHODS

Data were from the Aboriginal Birth Cohort study, a prospective longitudinal investigation of Aboriginal individuals born 1987-1990 at an Australian regional hospital. Models representing demographic, socioeconomic, behavioural, dental service utilization and clinical oral health variables were tested using multivariate regression.

RESULTS

The percent DT>0 was 72.9 (95% CI 68.7-77.1), mean DT was 4.19 (95% CI 3.8-4.6), percent DMFT>0 was 77.4 (95% CI 73.5-81.3) and mean DMFT was 4.84 (95% CI 4.4-5.3). After controlling for other covariates, risk indicators for percent DT>0 included soft drink consumption every day or a few times a week (PR 1.25, 95% CI 1.08-1.45), not consuming milk every day or a few times a week (PR 1.16, 95% CI 1.04-1.30) and sweet consumption every day or a few times a week (PR 1.18, 95% CI 1.04-1.33). Risk indicators for mean DT included sweet consumption every day or a few times a week (B=1.14, 95% CI 0.27-2.02), nonownership of a toothbrush (B=0.91, 95% CI 0.10-1.87) and presence of plaque (B=2.46, 95% CI 0.96-3.96). Those with 4 +  occupants in their house the previous night had 1.2 times the prevalence of having DMFT>0 than their counterparts with less household occupants (95% CI 1.01-1.49). Percent DMFT>0 was also associated with consumption of soft drink every day or a few times a week (PR 1.18, 95% CI 1.04-1.34) and consumption of sweets every day or a few times a week (PR 1.23, 95% CI 1.10-1.37). Mean DMFT was higher among those who consumed sweets every day or a few times a week (B = 0.13, 95% CI 0.05-0.22) and who had dental anxiety (B=0.10, 95% CI 0.01-0.19).

CONCLUSIONS

In an Australian Aboriginal young adult cohort, risk indicators for dental caries included social determinants such as household size, dietary behaviours such as regular consumption of soft drink and sweets, dental behaviour such as nonownership of a toothbrush and dental anxiety.

Imaging Natural Occlusal Caries Lesions with Optical Coherence Tomography

Several studies have demonstrated that polarization-sensitive optical coherence tomography (PS-OCT) can be used to nondestructively measure the severity of demineralization in the important occlusal surfaces. The purpose of this study was to assess the potential of PS-OCT and OCT methods for the measurement of the depth of natural occlusal carious lesions. Teeth were screened for potential occlusal lesions using near infrared imaging (NIR). A PS-OCT system operating at 1310-nm was used to acquire polarization resolved images of the area of interest on the occlusal surface. The teeth were serial sectioned to 200 μm thickness and examined with polarized light microscopy (PLM) and Transverse Microradiography (TMR) for comparison. The lesion depth measured nondestructively with PS-OCT was compared to the lesion depth measured with PLM and TMR to assess the performance of these methods and determine if polarization sensitivity is required. The lesion depth measured using OCT correlated well with the lesion depths measured with TMR and PLM. Although polarization sensitivity provided better contrast it was not necessary to have polarization sensitivity to identify deep occlusal lesions.

Development, methodology and potential of the new Universal Visual Scoring System (UniViSS) for caries detection and diagnosis

Given the limitations of adjunct caries detection and diagnostic tools, e.g., imperfect validity and reproducibility, as well as the difficulties in controlling all possible confounding factors, the need for an objective visual caries detection and diagnosis system has become evident. Our work has therefore aimed at systematizing caries lesions with the Universal Visual Scoring System (UniViSS) for occlusal and smooth surface lesions, which can be used for primary and permanent teeth, as well as under clinical, epidemiological, public health and laboratory conditions. Besides the description of the development and methodology of UniViSS, it is shown that UniViSS allows an accurate and reproducible classification of caries lesions on occlusal surfaces.

Phylogenetic analyses and detection of viridans streptococci based on sequences and denaturing gradient gel electrophoresis of the rod shape-determining protein gene

Background

Population analysis of viridans streptococci is important because these species are associated with dental caries, bacteremia, and subacute endocarditis, in addition to being important members of the human oral commensal microbiota.

Design

In this study, we phylogenetically analyzed the rod shape-determining protein gene (rodA), which is associated with cellular morphology, cell division, and sensitivity for antibiotics, and demonstrated that the diversity of the rodA gene is sufficient to identify viridans streptococci at the species level. Moreover, we developed a more convenient denaturing gradient gel electrophoresis (DGGE) method based on the diversity of the rodA gene (rodA-DGGE) for detecting nine dominant streptococcal species in human saliva, namely, Streptococcus sanguinis, Streptococcus oralis, Streptococcus mitis, Streptococcus parasanguinis, Streptococcus gordonii, Streptococcus vestibularis, Streptococcus salivarius, Streptococcus mutans, and Streptococcus sobrinus.

Results

This rodA-DGGE method proved useful in detecting viridans streptococci without cultivation, isolation, and phenotypic characterization.

Conclusion

Analysis of the oral microbiota by rodA-DGGE offers a higher resolution than the conventional DGGE using 16S rDNA and may be an alternative in the microbial diagnosis of streptococcal infection.

Dental caries: A complete changeover (Part II)-Changeover in the diagnosis and prognosis

Realization that dental caries is a reversible, dynamic biochemical event at a micron level has changed the way the profession recognizes the caries disease and the caries lesion. The diagnosis of dental caries poses challenges due to the complex interaction of multiple endogenous causal factors. The most appropriate diagnostic aid for this purpose is the risk model of caries risk assessment. The analyses of the biological determinants provide clues to the dominant causal factor. The detection of a carious lesion has undergone a rigorous revision and revolution in order to identify the earliest mineral change so that it can be controlled without resorting to invasive management options. Apart from detection, it became mandatory to assess the extent of the lesion (noncavitated/cavitated), assess the activity status of the lesion (active/arrested), monitor the lesion progress (progression/regression over a period of time), and finally to predict the prognosis of the lesion as well as the disease. The prognosis of the disease can be best assessed by analyzing the predictor factors in caries risk assessment. The ultimate objective of such a meticulous and methodical approach aids in devising a tailor-made treatment plan, using preventing measures precisely and restorative measures minimally. This ensures the best oral health outcome of the patient.

Inhibitory Effects of Partially Decomposed Alginate on Production of Glucan and Organic Acid by Streptococcus sobrinus 6715

Our previous study has already clarified that partially decomposed alginate (Alg53) by Vibrio alginolyticus SUN53 has a competitive inhibitory effect on sucrase. The objective of this study is to evaluate the influence of Alg53 on the production of glucan from sucrose by glucosyltransferase and acid from glucose by Streptococcus sobrinus 6715. Glucosyltransferase was prepared from cultural medium of S. sobrinus using ultrafiltration and hydroxyapatite chromatography. In order to examine the inhibitory effect of Alg53 for production of glucan by GTase, partially purified GTase, sucrose and Alg53 solution were incubated at 37°C. The influence of Alg53 on the production of acid from glucose was evaluated by a degree of pH decline during the incubation for 60 min. The original Alg53 solution markedly inhibited to 21% of the synthesis of water-insoluble glucan from sucrose and that of 10-fold diluted of Alg53 solution was 23%. However, the production of water-soluble glucan from sucrose by GTase was hardly affected by Alg53. Furthermore, Alg53 suppressed dose-dependently pH decline by organic acid converted from glucose. These results suggest that Alg53 is expected as a functional food material which prevents or reduces dental caries.

Dental findings in Cornelia de Lange syndrome

Cornelia de Lange syndrome is a congenital disease, basically characterized by psychomotor retardation associated with a series of malformations, including mainly skeletal, craniofacial deformities together with gastrointestinal and cardiac malformations. There is no definitive biochemical or chromosomal marker for the prenatal diagnosis of this syndrome. We actually want to present the case of a 10-year-old patient, who was admitted to our clinic for dental pain. The patient had the symptoms of Cornelia de Lange syndrome. During the oral examination of this patient, the patient was found to have the typical symptoms of Cornelia de Lange syndrome, such as micrognathia and delayed eruption in conjunction with the symptoms of the Hutchinson's syndrome, which had never been reported before.

Oral health-related quality of life in a birth cohort of 32-year olds

OBJECTIVES

To describe oral health-related quality of life (OHRQoL) among New Zealand adults and assess the relationship between clinical measures of oral health status and a well-established OHRQoL measure, controlling for sex, socioeconomic status (SES) and use of dental services.

METHODS

A birth cohort of 924 dentate adults (participants in the Dunedin Multidisciplinary Health and Development Study) was systematically examined for dental caries, tooth loss, and periodontal attachment loss (CAL) at age 32 years. OHRQoL was measured using the 14-item Oral Health Impact Profile questionnaire (OHIP-14). The questionnaire also collected data on each study member's occupation, self-rated oral health and reasons for seeing a dental care provider. SES was determined from each individual's occupation at age 32 years.

RESULTS

The mean total OHIP-14 score was 8.0 (SD 8.1); 23.4% of the cohort reported one or more OHIP problems 'fairly often' or 'very often'. When the prevalence of impacts 'fairly/very often' was modeled using logistic regression, having untreated caries, two or more sites with CAL of 4+ mm and 1 or more teeth missing by age 32 years remained significantly associated with OHRQoL, after adjusting for sex and 'episodic' dental care. Multivariate analysis using Poisson regression determined that being in the low SES group was also associated with the mean number of impacts (extent) and the rated severity of impacts.

CONCLUSIONS

OHIP-14 scores were significantly associated with clinical oral health status indicators, independently of sex and socioeconomic inequalities in oral health. The prevalence of impacts (23.4%) in the cohort was significantly greater than age- and sex-standardized estimates from Australia (18.2%) and the UK (15.9%).

High contrast near-infrared polarized reflectance images of demineralization on tooth buccal and occlusal surfaces at lambda = 1310-nm

BACKGROUND AND OBJECTIVES

Sound enamel manifests peak transparency in the near-IR (NIR) at 1310-nm, therefore the near-IR is ideally suited for high contrast imaging of dental caries. The purpose of this study was to acquire images of early demineralized enamel on the buccal and occlusal surfaces of extracted human teeth using NIR reflectance imaging and compare the contrast of those images with the contrast of images taken using other methods.

MATERIALS AND METHODS

Fifteen human molars were used in this in vitro study. Teeth were painted with a clear acid-resistant varnish, leaving two 2 mm x 2 mm windows on the buccal and occlusal surfaces of each tooth for demineralization. Artificial lesions were produced in the exposed windows after a 2-day exposure to a demineralizing solution at pH 4.5. Lesions were imaged using NIR transillumination, NIR and visible light reflectance, and fluorescence imaging methods. Crossed polarizers were used where appropriate to improve contrast. Polarization sensitive optical coherence tomography (PS-OCT) was also used to non-destructively assess the depth and severity of demineralization in each sample window.

RESULTS

NIR reflectance imaging had the highest image contrast for both the buccal and occlusal groups and it was significantly higher contrast than visible light reflectance (P < 0.05).

CONCLUSION

The results of the study suggest that NIR reflectance imaging is a promising new method for acquiring high contrast images of early demineralization on tooth surfaces.

Near-IR Multi-modal Imaging of Natural Occlusal Lesions

Reflectance and transillumination imaging show demineralization with high contrast in the near-IR. The objective of this study is to use lesion size and contrast acquired in reflectance and transillumination near-infrared imaging modes to estimate the severity of natural occlusal caries lesions. Previous studies have shown that near-infrared (NIR) light can be used to effectively image artificial carious lesions. However, its efficacy on natural lesions requires further exploration. Fifty extracted teeth with varying amounts of occlusal decay were examined using a NIR imaging system operating at 1310-nm. Image analysis software was used to calculate contrast values between sound and carious tooth structure. After imaging, teeth were histologically sampled at 1-mm intervals in order to determine lesion depth. Lesion contrast in transillumination mode significantly increased with lesion depth (p<0.001), while lesion contrast in reflectance mode did not increase. The lesion area demonstrated a significant increase with lesion severity in both imaging modes. These results suggest that lesion contrast and area can be used to estimate lesion severity in NIR images.

Influence of preventive dental treatment on mutans streptococci counts in patients undergoing head and neck radiotherapy

The aim of this study was to evaluate the influence of chlorhexidine gluconate, sodium fluoride and sodium iodine on mutans streptococci counts in saliva of irradiated patients.

MATERIAL AND METHODS

Forty-five patients were separated into three experimental groups and received chlorhexidine (0.12%), sodium fluoride (0.5%) or sodium iodine (2%), which were used daily during radiotherapy and for 6 months after the conclusion of the treatment. In addition, a fourth group, composed by 15 additional oncologic patients, who did not receive the mouthwash or initial dental treatment, constituted the control group. Clinical evaluations were performed in the first visit to dental clinic, after initial dental treatment, immediately before radiotherapy, after radiotherapy and 30, 60, 90 days and 6 months after the conclusion of radiotherapy. After clinical examinations, samples of saliva were inoculated on SB20 selective agar and incubated under anaerobiosis, at 37ºC for 48 h. Total mutans streptococci counts were also evaluated by using real-time PCR, through TaqMan system, with specific primers and probes for S. mutans and S. sobrinus.

RESULTS

All preventive protocols were able to reduce significantly mutans streptococci counts, but chlorhexidine gluconate was the most effective, and induced a significant amelioration of radiotherapy side effects, such as mucositis and candidosis.

CONCLUSION

These results highlights the importance of the initial dental treatment for patients who will be subjected to radiotherapy for head and neck cancer treatment.

Detection of oral streptococci in dental biofilm from caries-active and caries-free children

This work correlated the presence of oral streptococci in dental biofilm with clinical indexes of caries and oral hygiene in caries-active and caries-free children. S. mutans and/or S. sobrinus in the dental biofilm does not indicate a direct risk for developing dental caries.

The Prevalence of Self-Reported Halitosis and Oral Hygiene Practices among Libyan Students and Office Workers

AIMS

The aims of this study were to assess the prevalence of self-reported halitosis, oral hygiene practices and related diseases among Libyan students and employees.

METHODS

Six hundred self-administered structured questionnaires were used to investigate self-perception of halitosis and oral hygiene practices among a group of Libyan volunteers. Chi square test was used to detect significant differences between frequencies and to test correlation between self-perception of halitosis and measures of oral hygiene.

RESULTS

Forty three percent of the subjects were males and 57% were females. Forty four percent of the males and 54% of the females revealed self-perception malodour. Malodour was reported with the highest frequency (68%) during wake up time. Malodour was perceived by 31.7% of the females and 23.4% of the males during the hand-on-mouth test (p=0.04). Significantly more females (89.9%) than males (75.7%) practiced brushing (p<0.001). Fifty one percent of the males and 49.6% of females had dental caries. Smoking was significantly (p<0.001) more prevalent among males (17%) than among females (1%). Brushing was practiced by 85% of non-smokers and 68% of smokers (p=0.004). About 71% of the subjects who practiced brushing reported malodour during wake up time in comparison to subjects who did not practice brushing (p=0.041).

CONCLUSIONS

The prevalence of self-perceived malodour among the Libyan volunteers in this study is within the range of other studies. There is a great demand to reduce the incidence of dental caries and periodontal diseases.

Dental caries experience in 12-year-old schoolchildren in southeastern Brazil

The aim of this study was to evaluate the prevalence of caries-free children using DMFT and significant caries (SiC) indexes in different caries prevalence groups in cities of the region of Campinas, São Paulo State, Brazil. The methodology proposed by the World Health Organization (1997) was used for caries diagnosis in 2,378 individuals. According to the DMFT index obtained in each evaluated city, 3 prevalence groups with representative samples were formed, being classified as low, moderate and high. SiC index was used to classify the one third of the population with the highest caries prevalence. In the low prevalence group, 32.4% of the children were caries free (DMFT=0), with mean DMFT of 2.29 and SiC index of 4.93. In the moderate prevalence group, 21.8% of the children were caries free, with mean DMFT of 3.36 and SiC of 6.74. Only 6.9% of the children in the high prevalence group were caries free and the mean DMFT was 5.54 (SiC=9.62). There was a great heterogeneity in dental caries distribution within the studied population, as well as a high caries prevalence considering the 3 classifications. Other indexes besides DMFT could be used to improve oral health assessment during establishment of the treatment plan and intervention.

Slow-release fluoride devices: a literature review

Although the prevalence of caries has decreased dramatically over the past decades, it has become a polarised disease, with most of subjects presenting low caries levels and few individuals accounting for most of the caries affected surfaces. Thus it become evident for the need of clinical approaches directed at these high-risk patients, in order to overcome problems related to compliance and low attendance at dental care centres. Slow-release fluoride devices were developed based on the inverse relationship existing between intra-oral fluoride levels and dental caries experience. The two main types of slow-release devices - copolymer membrane type and glass bead - are addressed in the present review. A substantial number of studies have demonstrated that these devices are effective in raising intra-oral F concentrations at levels able to reduce enamel solubility, resulting in a caries-protective effect. Studies in animals and humans demonstrated that the use of these devices was able to also protect the occlusal surfaces, not normally protected by conventional fluoride regimens. However, retention rates have been shown to be the main problem related to these devices and still requires further improvements. Although the results of these studies are very promising, further randomised clinical trials are needed in order to validate the use of these devices in clinical practice. The concept of continuously providing low levels of intra-oral fluoride has great potential for caries prevention in high caries-risk groups.

Accuracy of digital subtraction radiography in combination with a contrast media in assessment of proximal caries depth

BACKGROUND AND AIMS

Radiography is used to diagnose the demineralization process and carious lesions; however, conventional radiography and direct digital images do not show these lesions when the amount of demineralization is less than 40%. Digital subtraction radiography has recently been used to improve the diagnostic quality of these le-sions. The purpose of this study was to compare the caries depth estimated by digital subtraction radiog-raphy in combination with barium sulfate in diag-nosing proximal dental caries with histopathologic evaluation.

MATERIALS AND METHODS

In this study 30 molars and premolars (24 demineralized lesions with cavity, 8 without cavity) were studied. Direct digital images were taken (kVp: 68, mA: 8; t: 0.12 for premolars and t: 0.16 for molars) whereas the position of X-ray tube and CCD receptor and teeth was fixed. To prepare the second images 135 gr/L barium sulfate was used. The images obtained with the same exposure and geometry and then subtracted. The depth of the lesions in direct digital and subtracted images were assessed and compared with the depth measured in histopathologic assessments.

RESULTS

The mean depths (± SD) of the lesions were 1.80 ± 0.77 mm in direct digital radiography, 2.32 ± 0.76 mm in subtracted images after barium sulfate treatment, and 2.51 ± 0.43 mm in histopathologic sections. The statistical difference between direct digital radiography and the other methods was significant (P < 0.05). However, the differences were not statistically significant between subtracted images and histopathologic sections. The average intra-class correlation coefficient was 0.7241 (CI: 95%).

CONCLUSION

The present study has demonstrated that digital subtraction radiography images have the potential to measure the depth of proximal caries with no significant difference with histopathologic evaluation.

Association of environmental cadmium exposure with pediatric dental caries

BACKGROUND

Although animal experiments have shown that cadmium exposure results in severe dental caries, limited epidemiologic data are available on this issue.

OBJECTIVES

We aimed to examine the relationship between environmental cadmium exposure and dental caries in children 6-12 years of age.

METHODS

We analyzed cross-sectional data, including urine cadmium concentrations and counts of decayed or filled tooth surfaces, from the Third National Health and Nutrition Examination Survey. We used logistic and zero-inflated negative binomial (ZINB) regression to estimate the association between urine cadmium concentrations and caries experience, adjusting these analyses for potential confounders including environmental tobacco smoke (ETS).

RESULTS

Urine cadmium concentrations ranged from 0.01 to 3.38 ng/mL. Approximately 56% of children had experienced caries in their deciduous teeth, and almost 30% had been affected by caries in their permanent dentition. An interquartile range (IQR) increase in creatinine-corrected cadmium concentrations (0.21 microg/g creatinine) corresponded to a 16% increase in the odds of having experienced caries in deciduous teeth [prevalence odds ratio (OR)=1.16; 95% confidence interval (CI), 0.96-1.40]. This association was statistically significant in children with low ETS exposure (prevalence OR=1.30; 95% CI, 1.01-1.67). The results from the ZINB regression indicated that, among children with any caries history in their deciduous teeth, an IQR increase in cadmium was associated with 17% increase in the number of decayed or filled surfaces. We observed no association between cadmium and caries experience in permanent teeth.

CONCLUSIONS

Environmental cadmium exposure may be associated with increased risk of dental caries in deciduous teeth of children.

High-resolution PS-OCT of Enamel Remineralization

Previous studies have demonstrated that Polarization Sensitive Optical Coherence Tomography (PS-OCT) can be used to image the remineralization of early artificial caries lesions. However, the depth resolution of the imaging system employed in those previous studies was limited and the outer surface structure of the lesions were not resolved as clearly as desired. The purpose of this study was to repeat the earlier remineralization study using a broadband light-source of higher resolution to determine if there can be improved resolution of the remineralized surface zones of the lesions. An all polarization-maintaining fiber based PS-OCT system operating at 1310-nm was used to acquire polarization resolved images of bovine enamel surfaces exposed to a demineralizing solution at pH-4.9 followed by a fluoride containing remineralizing solution at pH-7.0 containing 2-ppm fluoride. The structure of the surface zones could be clearly resolved using PS-OCT in the samples that underwent remineralization. The PS-OCT measurements indicated a significant (p<0.05) reduction in the integrated reflectivity between the severity of the lesions that were exposed to the remineralization solution and those that were not. The lesion depth and mineral loss were also measured with polarized light microscopy and transverse microradiography after sectioning the enamel blocks. These results show that PS-OCT can be used to non-destructively monitor the remineralization potential of anti-caries agents.

Association between Dental Caries and Body Mass Index-For-Age among 6-11-Year-Old Children in Isfahan in 2007

BACKGROUND AND AIMS

Childhood obesity has been associated with high refined sugar intake. The relationship between sucrose intake and development of dental caries has been established. The aim of this study was to determine the association between age-specific body mass index (BMI-for-age) and dental caries in children.

MATERIALS AND METHODS

In this cross-sectional study a total of 1003 children were screened. Weight, height, BMI-for-age and dental caries of 633 (317 boys, 316 girls) 6-11-year-old children were clinically examined for dental caries using the World Health Organization criteria by a dentist on a dental chair. Decayed and filled teeth (DFT/dft) indices were used. BMI-for-age and dental caries were analyzed with multiple linear regression, chi-square, and t-tests using SPSS computer software.

RESULTS

The findings showed that 16% of the children had a normal weight, 16.9% were at risk of overweight, and 67.1% were overweight. In the normal weight, at risk of overweight, and overweight groups, the mean ± SE for DFT were 0.34 ± 0.08, 1.23 ± 0.13 and 0.73 ± 0.05, respectively; and 2.01 ± 0.19, 2.76 ± 0.18 and 2.59 ± 0.13 respectively, for dft. Multiple linear regression showed that there was no statistically significant association between BMI-for-age and DFT (R = 0.06) and dft (R = 0.07) indices. 27.7%, 14% and 37.2% of children with normal weight, at risk of overweight and with overweight were caries free, respectively. There was statistically significant association between BMI-for-age and being caries free (p = 0.0001).

CONCLUSION

There was no association between BMI-for-age and DFT/dft indices. In addition, a high prevalence of at risk of overweight and overweight was seen among 6-11-year-old children in Isafahan, Iran.

Prevalence and bilateral occurrence of first permanent molar caries in 12-year-old students

Background and aims

Dental caries is one of the most prevalent chronic diseases in children and DMFT index is the most important quantitative factor for measuring tooth health. The purpose of the present study was to determine prevalence and bilateral occurrence of first permanent molar caries in 12-year-old Iranian students.

Materials and methods

This cross-sectional study was carried out on 563 twelve-year-old stu-dents (307 boys and 256 girls), randomly selected from private and public schools of Rafsanjan, Iran, in 2006. All students were examined clinically for dental caries using the World Health Organization (WHO) criteria by a specialist on a dental chair in Rafsanjan Dental School. Data was analyzed using chi-square and t-test.

Results

The mean DMFT score of first permanent molars was 1.9 ± 1.6 (1.83 boys, 1.98 girls) and 31.4% (32.9% boys, 29.7% girls) of the students were caries free. There were no significant differences between boys and girls. Decayed (D) component yielded to be 40.9%, missing (M) 0.35% and filled (F) 6.22%. Maxillary and mandibular first permanent molars had 80.8% and 84% bilateral caries occurrence, respectively. There were no significant differences between the caries prevalence of right and left sides.

Conclusion

Caries prevalence among 12-year-old students in Rafsanjan, Iran is less than the global standards of WHO and FDI for 2000, but close to the gold standard for 2010. Bilateral caries occurrence in the first permanent molars was concluded to be high in the study population.

Developing Public Health Interventions with Xylitol for the US and US-Associated Territories and States

This paper examines how the limited exposure of the professional dental community in the United States to the potential caries reduction benefits of xylitol, and the absence of vehicles for xylitol that could be recommended in private practice settings or applied in public health programs, has retarded xylitol's adoption. Few papers appeared in the English language literature prior to the last two decades but now a greater number are appearing. Current work at the University of Washington has led to a series of randomized controlled trials more clearly establishing dosing and frequency guidelines and increased interest in use of xylitol products for caries prevention. Steps to develop effective alternative vehicles for the delivery of xylitol particularly useful for young children and institutional settings in America, and their bioequivalency, are explored.

Lead levels in blood and saliva in a low-income population of Detroit, Michigan

The relationships between blood lead (PbB) and saliva lead (PbSa) concentrations and the determinants of PbB and PbSa status in 970 low-income adults in the city of Detroit, Michigan were explored. Average PbB and PbSa values in the sample population were found to be 2.7+/-0.1 microg/dl and 2.4+/-0.13 microg/l (equivalent to 0.24+/-0.13 microg/dl), respectively, and a weak but statistically significant association was found between the lead levels in the two types of body fluid samples. The average PbB level for men (4.0+/-0.56 microg/dl) was higher than that for women (2.7+/-0.11 microg/dl); other significant predictors of PbB included age, level of education, being employed, income level, the presence of peeling paint on the wall at home and smoking. There was no gender- or age-dependent difference in blood saliva values but statistically significant correlations were found between PbSa and level of education, employment, income level and smoking. Dental caries was severe in this population. Only 0.5% of the participants had no clinical signs of caries, over 80% had cavitated carious lesions (i.e., lesions that had progressed into dentin), and the number of lost teeth and carious lesions averaged 3.4 and 30, respectively. Weak but significant associations were found between PbB as well as PbSa and measures of dental caries in the study population. The positive associations are believed to be a reflection of the fact that the risk factors for dental caries, especially in low-income populations of the US, overlap extensively with those of lead poisoning and may not have a causal significance.

Magnitude and determinants of exodontia in South Batinah region of Oman: A cross sectional study

OBJECTIVES

To estimate the magnitude, determinants and causes of exodontia presented at all the three dental units of South Batinah region of Oman.

METHODS

This is a cross sectional study of 8,963 samples representing dental cases reported at the three dental units for 12 weeks in year 2000. The information on patients undergoing exodontia and its indications were collected from their case files. Standard definitions were used to categorise causes of exodontia. Mid 2000 population was used as reference for calculating rates. Age-sex standardisation and 95% confidence interval of the exodontia rates were calculated for statistical validation.

RESULTS

The annual exodontia rate was 16.67 per 1,000 population (CI95% 16.52, 16.82). The rate in males was 11.56 (CI95% 11.40, 11.73) and and in females, 40.04 (CI95% 39.73, 40.34). The rate in the 12+ age group was significantly higher than that in the 0-12 age group. The rates showed geographic differences.

CONCLUSIONS

The exodontia rates were high in the study area. Exodontia rates were significantly higher in females, persons older than 12 years, and those living in the coastal areas of South Batinah. Based on the exodontia rates, the impact on the oral health services was reviewed and recommendations for improving the dental care were proposed.

A Mathematical Model for Dental Caries: A Coupled Dissolution-Diffusion Process

Demineralization of tooth mineral in the caries process was studied using a computer model that simulates a diffusion controlled dissolution process. The model consists of a two-compartment system. An acidic solution in the outer ("plaque") compartment was assumed to be large in volume so that its composition remained constant during the process. The solution in the inner ("lesion") compartment was in equilibrium with the tooth mineral, but its composition changed in response to diffusion of ions between the two solutions through an infinitely thin barrier. The permselectivity of the diffusion barrier to cations and anions can be modified as desired thus allowing the effects of membrane on the diffusion-dissolution process to be examined. Because the losses of calcium (Ca) and phosphate (P) from the "lesion" to the "plaque" generally does not occur at a molar ratio of 5/3, the Ca to P ratio of the dissolving mineral, the composition of the "lesion" fluid can change significantly from the starting composition, and this in turn modifies the Ca and P fluxes. A steady state condition is eventually reached under which the ratio of flux of Ca to that of P becomes 5/3. The results of the simulation show that for a given "plaque" pH, the rate of demineralization at steady state was the highest for cation and the lowest for anion permselective membranes. These results were in good agreement with those from an experimental study under comparable conditions.

Digital Image Analysis Assisted Microradiography-Measurement of Mineral Content of Caries Lesions in Teeth

This study investigated the feasibility of using a digital image analysis system to process the information contained in microradiographs of tooth sections that included dental caries lesions. The results show that by using an aluminum step wedge to provide a range of thickness standards and a sound area of the sample as an internal reference, data on tooth mineral content as a function of the location can be obtained with an estimated error of less than 5% relative to the mineral content of sound area. This microradiographic technique allows the response of tooth samples to a remineralization treatment to be quantitatively measured and statistically analyzed.

Medication caries: another form of "snacking"

The use of fluoride, frequent brushing and flossing, regular dental examinations, and limiting the ingestion of sweet snacks between meals are of primary importance in preventing dental caries. Because many commonly used medications have high concentrations of sucrose, the child with a chronic illness who needs medication on a long-term basis is at higher risk both for caries formation and for compliations of tooth decay. To minimize this risk most medication should be considered equivalent to a sweet snack for the purpose of dental hygiene. Sucrose in medication should be replaced by less cariogenic sweeteners, and sucrose-containing medications should be given with meals if this is possible.

Fluoride and dental health

Studies conducted under the widest variety of controlled conditions attest to the safety, efficacy, and cost benefits of fluoridation. A program that combines the use of systemic and topical fluoride results in maximum benefits. The author of this article reviews the metabolism of fluoride and its mechanism of action, and discusses practical modes of employing fluoride in caries prevention with special emphasis on the use of fluoride supplements for infants and young children in areas of non-fluoridated water. The author also discusses the factors responsible for the dramatic decline in caries prevalence in the industrialized nations.

Dental caries

Dental caries is one of the most prevalent diseases afflicting mankind. It reached a peak in the 1950s but has been declining drastically in recent years in children and young adults. This article describes the three contributing factors in dental caries: microbial plaque, tooth susceptibility, and diet, and discusses practical preventive measures which help to reduce caries incidence. Some of these, such as vaccines and antimicrobial varnishes, are still in the research stages, while others, such as sucrose substitutes, low-calorie sweeteners, and limitation of frequency of sugar snacks are well established and can be promoted by family physicians.