University of North Carolina Caries Risk Assessment Study: comparisons of High Risk Prediction, Any Risk Prediction, and Any Risk Biologic models

The purpose of this analysis is to compare three different statistical models for predicting children likely to be at risk of developing dental caries over a 3-yr period. Data are based on 4117 children who participated in the University of North Carolina Caries Risk Assessment Study, a longitudinal study conducted in the Aiken, South Carolina, and Portland, Maine areas. The three models differed with respect to either the types of variables included or the definition of disease outcome. The two "Prediction" models included both risk factor variables thought to cause dental caries and indicator variables that are associated with dental caries, but are not thought to be causal for the disease. The "Etiologic" model included only etiologic factors as variables. A dichotomous outcome measure--none or any 3-yr increment, was used in the "Any Risk Etiologic model" and the "Any Risk Prediction Model". Another outcome, based on a gradient measure of disease, was used in the "High Risk Prediction Model". The variables that are significant in these models vary across grades and sites, but are more consistent among the Etiologic model than the Predictor models. However, among the three sets of models, the Any Risk Prediction Models have the highest sensitivity and positive predictive values, whereas the High Risk Prediction Models have the highest specificity and negative predictive values. Considerations in determining model preference are discussed.     

The University of North Carolina caries risk assessment study: caries increments of misclassified children

The University of North Carolina caries risk assessment was conducted between 1986 and 1989 with 5000 children initially in grades 1 and 5 from low fluoride sites in South Carolina and Maine. Clinical, microbiologic, behavioral, and demographic factors served as independent variables used in logistic multiple regression models to determine the predicted caries risk classification of each child. The 3-yr DMFS increment of each child was the dependent variable, and the 20-25% of those in each cohort with the highest increment were considered the high risk group. Sensitivity and specificity values averaged 0.60 and 0.83 respectively, indicating the misclassification of substantial numbers of children. This paper reports analysis of the DMFS increments of the misclassified children. The majority of children had DMFS increments within one or two surfaces of the classification cut points. Many false negative children had increments composed entirely of filled surfaces, often of minimal extent and without evidence of previous decay. Many false positive children had increments composed of decayed surfaces and would have benefitted from being identified as high risk and assigned to a preventive program. Other false positive children had sealants placed after the baseline examination that undoubtedly reduced their true increment. It is concluded that the consequences of misclassification are not serious for most children in this study.     

Comparative effectiveness of visual/tactile and simplified screening examinations in caries risk assessment

Central to the development of a model for identifying children at high risk to caries is a clinical evaluation to assess dental status and other conditions potentially useful in caries prediction. Traditionally, this evaluation has been based on a relatively lengthy visual/tactile examination conducted by a dentist. Replacing the dentist examination with a dental auxiliary conducted screening evaluation could lead to reduced time and costs. The 4-yr University of North Carolina Caries Risk Assessment Study involved approximately 5000 schoolchildren initially in Grades 1 and 5 living near Aiken, South Carolina, and Portland, Maine. The effectiveness of caries prediction models using visual/tactile examination data were compared with the same models using simplified screening evaluation data. Results showed sensitivity ranged from 0.57 to 0.61 for the visual/tactile and screening models by site and grade cohort. Specificity for the models ranged from 0.80 to 0.83. None of these differences in sensitivity and specificity between visual/tactile (dentist) and screening (hygienist) models was statistically significant. Findings show that for the prediction of children at high risk to dental caries the clinical evaluation may be conducted with no reduction of precision by using dental hygienist performed screening evaluations rather than dentist conducted visual/tactile examinations. While no cost data were collected, these results imply that costs to future prediction programs could be reduced by using screening evaluations.     

University of North Carolina Caries Risk Assessment Study. III. Multiple Factors in Caries Prevalence

The baseline caries experienced of approximately 5,000 children in South Carolina and Maine was used as the dependent variable in caries risk assessment analyses. Clinical, microbiologic, and demographic factors served as independent variables in a multivariate relationship to caries through regression and discriminant function analyses. Four factors--number of dental visits by the child in the past year, presence of white spot lesions, and both the urgency of need for restorative care and the future caries increment predicted by the examiner--associated significantly and consistently with caries prevalence in primary and permanent teeth of first and fifth graders at both study sites. Several factors associated significantly with caries prevalence at only one site or grade within a site, suggesting that wide applicability of a specific caries risk assessment model may be limited. In these analyses, sensitivity ranged from .60 to .72 and specificity varied from .86 to .91 in the four grade-site groups. The ultimate goal of this longitudinal study is to identify highly caries-prone children in time to prevent the occurrence of a future caries increment. Although the lack of consistent association of many variables, including microbiologic factors, with baseline caries prevalence was unexpected, it is expected that some of these variables will contribute predictive power in the prospective study.     

Exploring the contributions of components of caries risk assessment guidelines

Abstract – Objective: To examine the relative contribution of current caries activity, past caries experience, and dentists’ subjective assessment of caries risk classifications. Methods: Administrative data from two dental plans were analyzed to determine dentists’ risk classification, as well as current caries activity and previous caries experience at the time of the classification. The performance of these predictors in identifying patients who would experience subsequent caries was then modeled using logistic regression. Results: In both plans, current caries activity alone had relatively low sensitivity and high specificity in identifying patients who would experience subsequent caries. Sensitivity improved, but at the cost of specificity when previous caries experience was included in the models. Further improvement in sensitivity accrued when dentists’ subjective assessment was included, but performance was different in the two plans in terms of false‐positives. Conclusions: Consideration of previous caries experience tends to strengthen the predictive power of caries risk assessments. Dentists’ subjective assessments also tend to improve sensitivity, but overall accuracy may suffer.     

Three-year Root Caries Incidence and Risk Modeling in Older Adults in North Carolina

Objectives : The purposes of this study were to describe the incidence of root caries and to identify its risk factors in a representative sample of older adults. Methods : Root caries incidence was estimated and multivariate risk assessment models were developed to identify predictors for root caries in a three-year follow-up study of 234 black and 218 white noninstitutionalized adults aged 65 and older residing in North Carolina. Results : During the observation period, 29 percent of blacks developed root caries, compared to 39 percent of whites (P<.05). The mean net DFS increment per person was 0.55±0.13 root surfaces for blacks vs 0.80±0.21 for whites (P>.32). Multivariate logistic regression analysis indicated that blacks wearing a partial denture, having some root fragments, having an average gingival recession ≥2 mm, and being free of P. intermedia were at greater risk for developing new root caries. The model for whites showed that retired people with their most severe gingival recession ≥4 mm, an average probing pocket depth ≥2 mm, and taking antihistamines were more likely to develop new lesions. Conclusions : These findings suggest that older blacks had less risk of root caries than whites, and in both groups indicators of poor periodontal status increased the risk of root caries.     

Prediction of caries incidence in schoolchildren living in a high and a low fluoride area

Abstract – A salivary mutans streptococci test and past caries experience were used as predictors for caries increment in a 3-yr study comprising 655 12-yr-old schoolchildren from two areas with contrasting levels of fluoride in the drinking water. The mean caries (DMFS) increment was similar in both groups during the study period, but a significantly ( p < 0.05) higher incidence of approximal enamel lesions was registered in children from the high fluoride area. In both groups, a statistically significant ( p < 0.05-0.001) positive relationship between salivary mutans streptococci score and/or past caries experience at baseline on one hand and caries increment during the study period on the other was established. The past caries experience was the most powerful predictor of caries risk in both the low fluoride and the high fluoride area. The sum of the sensitivity and specificity was somewhat higher in the low fluoride area (138%) compared to the high fluoride area (123%). The salivary bacterial enumeration used alone or in combination with past caries experience as well as past approximal caries experience were less useful as predictors in both groups. The present findings indicate that the natural fluoride exposure has a limited influence on caries risk assessment and the caries predictive ability of the 'salivary bacterial test and past caries in populations with a low level of disease.     

Cariogram--a multifactorial risk assessment model for a multifactorial disease

This paper reviews some common methods for the assessment of caries risk. It also describes a new way of illustrating the caries risk profile of an individual, the Cariogram. Past caries experience and socioeconomic factors are often used for prediction of caries. As prediction models, the methods are simple, inexpensive and fast. However, they are not risk models, as they do not specify which particular risk factors are operating. Various biological factors can be used for risk assessment. Common ones are bacteria, diet and host factors. Taken separately, these biological factors often have limited predictive values. Socioeconomic factors often have a heavy impact on the biological factors as they can explain why an individual, for example, has a cariogenic diet or neglects oral hygiene. The biological factors are the immediate cause of the cavities. Caries experience is an illustration of how the host copes up with the biological activity. To facilitate the interpretation of biological data, the Cariogram was developed. It is a computer program showing a graphical picture that illustrates a possible overall caries risk scenario. The program contains an algorithm that presents a 'weighted' analysis of the input data, mainly biological factors. It expresses as to what extent different etiological factors of caries affect caries risk. The Cariogram identifies the caries risk factors for the individual and provides examples of preventive and treatment strategies to the clinician.     

Validation of a simple approach to caries risk assessment

OBJECTIVE: This study examined the predictive validity of a simple subjective method promoted to dentists for assessing their patients' caries risk. METHODS: Data from two large group practices that have used guideline-assisted caries risk assessment (CRA) for several years were analyzed retrospectively to determine the receipt of caries-related treatment following a CRA. Patient age and receipt of caries preventive treatment subsequent to the CRA were control variables in logistic regressions to determine the likelihood of caries-related treatment for low, moderate, and high risk groups. RESULTS: Among 45,693 individuals in the two plans, those categorized as being at high caries risk were approximately four times as likely to receive any caries-related treatment as those categorized as being at low caries risk. Those categorized as at moderate risk were approximately twice as likely to receive any treatment. In addition, for those at elevated risk who required any treatment, the number of teeth requiring treatment was larger. CONCLUSION: The results of this study provide the first large-scale, generalizable evidence for the validity of dentists' subjective assessment of caries risk.     

The value of salivary bacterial counts as a supplement to past caries experience as caries predictor in children

This study aimed to determine whether salivary mutans streptococci and lactobacilli counts could add any value to a combination of caries experience variables that was recently presented for the prediction of caries. Sixty-nine children at the age of 7.5 yr participated in this longitudinal study. Microbiological data were obtained at the ages of 7.5, 9.5 and 11.5 yr and caries data at the ages of 7.5. 9.5. 11.5, 13.5 and 15.5 yr. Spearman's correlation coefficients were computed, and forward multiple regression analyses were carried out using bacterial counts and caries experience parameters as explanatory variables and caries increment as a dependent variable. The explained variance (adjusted R2 value) was the measure used to assess the additional value of bacterial counts to the caries predictive potential of the combined parameters of the past caries experience. Correlation coefficients between bacterial counts and 4-yr caries increment were from 0.22 tip to 0.54. In all cases, the simultaneous streptococcus mutans-lactobacilli counts showed a statistically non-significant additional adjusted R2 value of <0.06. The results do not lend support to the concept that these salivary bacterial counts are useful additional caries predictors for the mixed dentition, when a combination of caries experience parameters is used.     

Dental caries risk in the U.S. Air Force

BACKGROUND: This study describes the dental caries risk in the active duty U.S. Air Force population from October 2000 through September 2004. METHODS: The authors used data collected from two Air Force databases (personnel and dental files) by cross-referencing Social Security numbers from both databases with date. RESULTS: During the study period, the percentages of people at high and moderate risk of developing caries decreased by 31 percent and 12 percent, respectively, while the percentage of people at low risk of developing caries increased by 9 percent. Among Air Force members who were enrolled continuously during the study period, the percentages at high and moderate risk of developing caries decreased by 57 percent and 18 percent, respectively, while the percentage at low risk of developing caries increased by 14 percent. The authors observed improvement in caries risk in 83 percent and 73 percent of the people at high and moderate caries risk, respectively, for those continuously enrolled. High caries risk was related inversely to age, rank, education and years in service. Also, tobacco users had an elevated risk of developing caries. CONCLUSIONS: The Air Force Dental Service has made great strides in improving the oral health of the Air Force population. The results of this study suggest that caries risk is decreasing in the Air Force population, but oral health disparities still exist and require further evaluation. CLINICAL IMPLICATIONS: This investigation suggests that a caries risk assessment can be conducted successfully, and caries risk can be reduced by using a comprehensive population-based prevention program. This caries risk assessment also can identify factors associated with dental caries disparities in a large-scale population.     

Prospective study of 5-year caries increment among children receiving comprehensive dental care in the New England children's amalgam trial

Abstract – Objective: To measure the 5‐year caries increment among high‐risk children during their participation in the New England Children’s Amalgam Trial (NECAT), and to evaluate sociodemographic factors that may account for any observed disparities. Methods: NECAT recruited 534 children aged 6–10 with at least two decayed posterior occlusal surfaces from urban Boston and rural Maine. After restoration of baseline caries and application of sealants to sound surfaces, NECAT continued to provide free comprehensive semiannual dental care to participants. The net caries increment of children who completed the 5‐year follow‐up (n = 429) was calculated and predictors of caries increment were investigated using multivariate negative binomial models. Results: The majority of children (89%) experienced new caries by the end of the 5‐year follow‐up. Almost half (45%) had at least one newly decayed surface by the first annual visit. At year 5, the mean number of new decayed teeth was 4.5 ± 3.6 (range 0–25) and surfaces was 6.9 ± 6.5 (range 0–48). Time trends showed a noticeably higher increment rate among older children and young teenagers. Multivariate models showed that age (P < 0.001), number of baseline carious surfaces (P < 0.001), and toothbrushing frequency (<1/day versus ≥2/day, P = 0.04) were associated with caries increment. Only 48 children (11%) did not develop new caries. Conclusions: Despite the receipt of comprehensive semiannual dental care, the vast majority of these high‐risk children continued to develop new caries within 5 years. While disparities were observed by age, extent of prior decay, and toothbrushing frequency, no other sociodemographic factors were associated with caries increment, suggesting that the dental care provided during the trial reduced sociodemographic disparities in prior caries experience that were observed at baseline.     

Eighteen-month Coronal Caries Incidence in North Carolina Older Adults

In this longitudinal study of a random sample of North Carolinians over the age of 65 and living in their homes, 325 blacks and 280 whites were examined and interviewed 18 months after baseline examinations. Coronal caries incidence was greater among whites than blacks. The increment due to teeth becoming root fragments were similar for both races; however, there were more newly crowned teeth among whites. Newly crowned surfaces were not used as part of the caries increment in logistic regression models to investigate potential risk predictors. For blacks, caries development over the 18-month period was associated with a higher lactobacillus score and more coronal caries at baseline, more previously filled coronal surfaces, and lack of active membership in clubs or other groups. For whites, having no self-reported tooth sensitivity, having a lower socioeconomic index score, taking antihistamine medications at baseline, and having the perception of more problems after the age of 40 than before were all associated with the development of coronal caries.     

Influence of the microbiological component of Cariogram® for evaluating the risk of caries in children

Objective: To compare the risk for caries in children as determined by Cariogram^® software (CS; Stockholm, Sweden) with and without its microbiological component and by a form based on Cariogram^® (FBC).

Methods: Children (n?=?28) aged 3–9 years were included. Data were collected clinically and from anamnesis. The salivary levels of Streptococcus mutans (SM) were evaluated. A linear regression model was used to determine which variables were predictive for each type of risk analysis. Caries risk was the dependent variable and the independent variables were caries experience, related disease, plaque amount, diet frequency, salivary levels of SM, fluoride sources and clinical judgment. A paired Student t-test was used for the following comparisons: (a) CS with and without SM; (b) CS without SM and FBC; (c) CS with SM and FBC.

Results: The mean dmft/DMFT was 5.56?±?2.51. There was no difference between the methods (p?p?=?.889). Caries experience, plaque amount, diet frequency and fluoride sources were predictors of caries risk in all assessment methods. Clinical judgment was a significant predictor in CS.

Conclusions: Caries experience, plaque amount, diet frequency and fluoride sources are valuable predictors of caries risk; microbiological tests are not necessary for evaluating caries risk in children, which can be assessed similarly by CS without SM and FBC.     

Community risk indicators for dental caries in schoolchildren: an ecologic study

Abstract A statewide survey of NC schoolchildren found wide variation in dental caries prevalence among sampled classrooms. This study examined factors associated with this variation using classrooms as a surrogate for the larger community, in order to identify community risk indicators (CRI). In all, 172 classrooms (3400 students) in Grades K-6 were available for analysis. Initially, 56 sociodemographic, environmental, health system, and clinical factors were evaluated for their association with caries prevalence (K-3: average dfs-f DMF'S; 4–6: average DMFS) using univariate and bivariate analyses. Of these, 21 factors met our criteria for evaluation using WLS multivariate regression. For Grades K-3 (w=108), population density, parental education, and coastal residence were negatively associated with caries scores, while age, and medical and dental Medicaid expenditures were positive. For Grades 4–6 (n=64), age and fs:dfs ratio were positively associated with caries scores, while population density, population: dentist ratio, and years of natural fluoride exposure were negative. CRIs for both models, when compared to individual models, explained a substantial portion of the variation in caries prevalence, 31% for Grades K-3 and 51% for Grades 4–6. Results suggest that a risk assessment model based on community rather than individual variables is feasible and further refinement may reveal factors useful in identifying high risk communities.     

A Best Practices Approach to Caries Management

Caries management by risk assessment represents best practices and is an evidence-based model that focuses on treating and preventing disease at the patient level rather than a surgical/restorative approach at the tooth level.BackgroundDental caries is a multifactorial, biofilm and pH mediated disease that affects people of all ages and disproportionally affects certain populations at epidemic proportions. Simply restoring cavitated teeth does nothing to resolve the disease. At the heart of the CAMBRA philiosphy is identifying the patient's unique risk level for future caries disease. This can be done by completing a caries risk assessment (CRA). Several easy to use CRA questionnaires are available. Once the patient's unique risk level has been determined, preventive and therapeutic interventions, based on the specific risk level, can then be implemented.MethodsLandmark publications, original research, and systematic reviews are analyzed and reviewed to form the basis for this shift in patient care related to caries disease.ConclusionsCaries management by risk assessment has emerged as the new paradigm in patient care and represents an evidence-based, best practices approach with the potential for significant advantages over traditional methods.     

The University of North Carolina Caries Risk Assessment Study I: Rationale and Content

This article presents the rationale and content of a current study that seeks to improve methods to identify children at high risk to dental caries. It summarizes the results of the development of a 12-factor, preliminary caries prediction model based on data derived from the National Preventive Demonstration Program. Despite data limitations, the model produced a sensitivity of .5 and specificity of .8 for four-year caries increment prediction in first- and fifth-grade children. Data on a number of additional potential predictors are being collected in two sites to expand and improve the existing model. These factors are identified.     

RISK INDICATORS AND RISK PREDICTORS OF DENTAL CARIES IN SCHOOLCHILDREN

The purpose of this study was to identify risk indicators of high caries level at baseline (HCLB) based on cross-sectional data and predictors of high caries increment (HCI) based on a 7-year-follow-up examination in 6-8-year-old schoolchildren. Two hundred and six schoolchildren were examined in 1997 and in 2004 by the same two calibrated dentists, in Piracicaba, Brazil. At baseline, dental caries, presence of sealants, fluorosis, and oral hygiene status were recorded. The children''s parents completed a questionnaire concerning socioeconomic level, fluoride use, dental service utilization, dietary and oral hygiene habits. HCLB and HCI were defined considering the upper quartile of the total caries experience distribution (dmfs+DMFS) and caries increment distribution, respectively. Logistic regression models were adjusted estimating the Odds Ratio (OR), 95% confidence intervals and p-values. Having white spot lesions (OR=5.25) was found to be a risk indicator of HCLB. Schoolchildren with dental fluorosis (OR=0.17) or those who brushed the teeth more than two times a day (OR=0.37) presented less probability of HCLB. The predictors of HCI were: dmfs>0 (OR=2.68) and mothers'' educational level up to 8 years of schooling (OR=2.87). Clinical and socioeconomic variables were found to be risk indicators and/or predictors of dental caries in schoolchildren.     

Frequency of initial caries lesions as predictor of future caries increment in children

Abstract — The aim of this study was to evaluate the predictive power of the frequency of initial caries lesions in selecting persons at high risk for caries. The subjects ( n = 124) were 11–13 yr old at the beginning of the follow-up. Caries was registered initially and after 5 yr. Evaluation of the predictions was based on cross-tabulations of the subjects according to their predicted caries risk and the actual 5-yr caries increment. Logistic regression analyses were used to produce the individual risk scores. In addition to the caries scores, age of the subjects, was included in the prediction function. In bivariate analyses the total initial caries score at baseline correlated better with caries increment than FS and DS scores did (r = 0.40, 0.13, and 0.31, respectively). When past caries experience was used as predictor, 69% of the children were classified correctly into the low and high risk groups. Surprisingly, only two more subjects (2%) were classified correctly when initial caries score was included in the function. These results suggest that inclusion of initial caries score adds little to the predictive power of the conventional DS and FS scores.     

Long-term effect of intensive caries prophylaxis

The purpose of the present study was to examine the long-term effect of intensive caries prophylaxis. A preventive program mainly based on professional toothcleaning was demonstrated to be highly effective against caries incidence over a 2-yr period. Five years after the termination of the test period 519 subjects, 17-21 yr of age, were reexamined. The results showed that 1) the smooth surface caries prevalence was very low, 2) a high number of the carious lesions became arrested with time, 3) a long-term effect seemed to be obtained in subjects at a high caries risk, and 4) salivary S. mutans and lactobacilli could be used for caries prediction over a 7-yr period.