The Core Curriculum in Cariology: Fiction or Reality? Challenges About Implementation.

INTRODUCTION: The Core Curriculum in Cariology (CCC) was developed by ORCA and ADEE in 2010. This article summarizes challenges for the implementation of the CCC at university/country level identified at the "Education Platform" of the ORCA 2022 conference in Cagliari, Sardinia. METHODS: Participants from Universities from 3 European (Italy, Poland, and UK), 2 Asian (India and Russia), and 3 American countries (Brazil, Colombia and USA) led the presentations, discussion, and generation of statements. Presentations were transcribed and summarized through qualitative content analysis. Key themes were identified, transformed into key topics, and sent to the panel for agreement. RESULTS: Regardless of the wide variety of dental schools per country, from few (Poland n=10) to many (India n=318, Brazil n=563), or from country/continent itself, frequent challenges to CCC implementation were highlighted. These included: lack of agreement on a basic CCC as standard (96%), insufficient support or reimbursement for caries prevention and management (90%), separation between cariology and restorative dentistry (68%), focus on restorative/surgical management with prevention and non-operative management being disconnected (73%). The group agreed that the integration of cariology and restorative dentistry remains essential to enhancing evidence-based decision-making, resulting in a shift of emphasis from cure to care. CONCLUSION: There is variation in the level of implementation of the CCC. A frequent challenge is the disconnect between cariology and restorative dentistry. The CCC should be disseminated and promoted as a uniform blueprint/framework to facilitate the implementation of a common cariology curriculum among universities within each country, as well as internationally.

Assessing the Acceptability of Less Invasive Caries Removal Techniques for treating Deep Carious Lesions: A Conjoint Survey among Dentists Practicing in a Midwestern American State.

This study identified factors that influence dentists' decisions regarding less invasive caries removal techniques such as stepwise removal (SW) and selective removal (SE) using a marketing research technique, conjoint analysis. A survey was sent to 1,434 dentists practicing in Iowa. Dentists were randomly assigned to receive a questionnaire to rate the likelihood they would use either SW/SE in hypothetical clinical scenarios. The scenarios were carefully created by conjoint design and included three relevant attributes: depth of lesion, hardness of carious dentin, and patient age. Descriptive and conjoint analyses were performed to assess trade-offs between these attributes, using SPSS. The study revealed that depth of lesion was the most important factor in the dentists' decisions (49 importance value) when choosing a SW to treat a deep carious lesion, followed by hardness of carious dentin and patient age (21 importance value). For the SE group, depth of the lesion was also the predominant factor when selecting a treatment. The study also identified that a high proportion of dentists (24.9%) indicated they would never consider using SW or SE under any circumstances. Our survey showed that depth of lesion was the most important reason to select a less invasive caries removal method. The high proportion of dentists indicating they would never consider selective caries removal (SE) techniques suggests that these less invasive options are underutilized.

Factors Associated with Reevaluation of the Stepwise Excavation Procedure: An 8-Year Retrospective Study.

Although the stepwise excavation procedure (SWP) has been shown to be an effective caries treatment technique, studies reporting its application outside of controlled clinical trials are limited. We performed a retrospective study from patient record data to assess the proportion of patients who had an SWP reevaluated within 18 months at The University of Iowa College of Dentistry (UICOD) between 2004 and 2012, and evaluated the association between different variables and this outcome. A total of 1,985 SWPs were performed in 1,326 patients, with 518 patients having had reevaluation within 18 months. Bivariate analysis and logistic regression modeling revealed strong associations between explanatory variables such as provider type, tooth type, patient age, number of recalls and the calendar year in which the SWP was done and reevaluation status. There was also evidence of association with dental insurance status. Other characteristics such as gender, distance traveled to the UICOD, number of surfaces treated and tooth arch did not show any significant association. In general, patients were more likely to have reevaluation when seen by faculty members or residents, the procedure was performed in molars/pre-molars, they were older, they had more recalls and were seen earlier in the study period. These results suggest that decisions to use SWP should consider patient demographics and treatment characteristics such as provider level, tooth type, patient age and number of recalls. The impact of treatment year may reflect program heterogeneity or temporal changes in external societal factors.

Predictors of survival of large non-occlusal non-incisal glass-ionomer restorations in older adults.

PURPOSE: This study aimed to investigate the predictors of survival of non-occlusal non-incisal glass-ionomer restorations as a surrogate for root surface restorations among older adults. METHODS: In a retrospective cohort analysis using the University of Iowa College of Dentistry electronic dental records, we included 721 patients aged 65+ who received 2+ surface non-occlusal non-incisal glass ionomer restorations placed from January 2005 - December 2011. Restorations were followed until September 2017 or until they were deemed to have failed. RESULTS: At baseline, participants' mean age was 77.6 ± 8.2 years, and 45.8% were females. Most patients were self-pay (65.2%). Most restorations were placed by residents and dental students (82.7%) and included only two surfaces (95.6%). About half (49.1%) failed during follow-up, with a median survival time of 3.7 years. The time ratio for lower incisors compared to other teeth was 0.6 (p = .006), for three-and-four-surface restorations compared to two was 0.7 (p = .007), for faculty as providers compared to residents and students was 1.4 (p = .039), and for the Geriatric & Special Needs Clinic compared to others was 0.8 (p = .013). Time ratios less than one indicate association with shorter durations for restorations, and time ratios greater than one indicate association with longer durations for restorations. CONCLUSION: Tooth type, number of restored surfaces, provider type, and clinic were all significant factors associated with survival of these restorations.

Effect of polishing direction on the marginal adaptation of composite resin restorations.

PROBLEM: Polishing composite resin restorations may lead to marginal defects and gap formation. PURPOSE: To assess the effect of polishing direction on the marginal adaptation of composite resin restorations using two composite resins and two polishing systems. MATERIALS AND METHODS: Forty extracted human molars were sectioned along their mesio-distal axis. Buccal and lingual enamel was flattened and a triangular preparation, 0.87-mm deep and 3-mm wide, representing two 60° bevels, was performed. Specimens were randomly assigned to eight groups (N = 20) and restored with two composite resins: a nanofilled (Filtek Supreme Ultra, 3M ESPE, St. Paul, MN, USA) or a microhybrid (Point 4, Kerr, Orange, CA, USA) and finished with two polishing techniques: polishing discs (Sof-Lex XT, 3M ESPE) or rubber polishers (HiLuster Plus, Kerr, Bioggio, Switzerland). On each specimen, both margins were polished with the same technique, one margin from composite resin to tooth and the other from tooth to composite resin. Replicas were made for field emission scanning electron microscope observation (200×) and quantitative margin analysis was performed based on four criteria. Data were analyzed with a paired-sample t-test, a two-sample t-test, and one-way analysis of variance or their nonparametric analog. RESULTS: Significant differences were found in most groups between polishing directions with better marginal adaptation from composite resin to tooth than from tooth to composite resin. Differences between composite resins and polishing techniques seemed to be dependent on certain combinations of composite resin, polishing technique, and polishing direction. CONCLUSION: Polishing from composite resin to tooth leads to better marginal adaptation than polishing from tooth to composite resin. CLINICAL SIGNIFICANCE: The results obtained from this in vitro study suggest that polishing direction influences the marginal adaptation of composite resins and that polishing from composite resin to tooth structure should be clinically performed whenever possible on accessible margins to preserve marginal integrity and esthetics.

Generalized permanent dentition fluorosis severity becomes less evident over time among a birth cohort.

Objectives: There are relatively few cohort studies which have examined changes in fluorosis appearance over time, and none of these have assessed changes in generalized fluorosis. In this analysis, we quantified and assessed changes in multiple measures of generalized fluorosis severity through childhood, adolescence, and young adulthood. Methods: Participants were from the Iowa Fluoride Study, a birth cohort recruited from 1992 to 1995. Permanent dentition fluorosis exams were carried out at ages 9, 13, 17, and 23 years using the Fluorosis Risk Index (FRI). Generalized fluorosis was assessed using mean FRI scores at the tooth- and person-level as well as a five-category measure of generalized fluorosis. Generalized fluorosis prevalence and severity was summarized at each time point and differences in adjacent time points were assessed using gamma statistics, signed-rank tests, and plotting changes in generalized fluorosis between adjacent time points. Results: We observed a statistically significant decline in the percentage of non-zero mean FRI scores at later exam ages at both the person- and tooth-levels. Based on our five-category generalized fluorosis measure, there were 34.0%-54.1% of participants with generalized fluorosis at baseline for each tooth group, and these percentages declined to 8.9%-27.2% at the age 23-year exam. Conclusions: We observed a statistically significant decline in generalized fluorosis severity scores and overall prevalence at later exam ages across all three measures of generalized fluorosis severity. This trend should be accounted for when estimating the prevalence of fluorosis in a population using fluorosis severity data collected in children and adolescents.

Longitudinal associations between children's dental caries and risk factors.

UNLABELLED: Dental caries is a common disease in children of all ages. It is desirable to know whether children with primary, mixed, and permanent dentitions share risk factors for cavitated and non-cavitated caries. OBJECTIVE: To assess the longitudinal associations between caries outcomes and modifiable risk factors. METHODS: One hundred and fifty-six children in the Iowa Fluoride Study met inclusion criteria of three dental examinations and caries-related risk factor assessments preceding each examination. Surface-specific counts of new non-cavitated caries and cavitated caries at the primary (Exam 1: age 5), mixed (Exam 2: age 9) and permanent (Exam 3: age 13) dentition examinations were outcome variables. Explanatory variables were caries-related factors, including averaged beverage exposure frequencies, tooth brushing frequencies, and composite water fluoride levels collected from 3-5, 6-8, and 11-13 years, dentition category, socioeconomic status, and gender. Generalized linear mixed models (GLMMs) were used to explore the relationships between new non-cavitated or cavitated caries and caries-related variables. RESULTS: Greater frequency of 100 percent juice exposure was significantly associated with fewer non-cavitated and cavitated caries surfaces. Greater tooth brushing frequency and high socioeconomic status (SES) were significantly associated with fewer new non-cavitated caries. Children had significantly more new cavitated caries surfaces at the mixed dentition examination than at the primary and permanent dentition examinations. CONCLUSIONS: There were common caries-related factors for more new non-cavitated caries across the three exams, including less frequent 100 percent juice exposure, lower tooth brushing frequency and lower SES. Less frequent 100 percent juice exposures might be associated with higher exposures to several other cariogenic beverages.

Mixed dentition cavitated caries incidence and dietary intake frequencies.

PURPOSE: This study examined risk factors for children having new cavitated caries between 5 and 9 years old. METHODS: Subjects were Iowa Fluoride Study cohort children (mostly Caucasian and of relatively high socioeconomic status) with both primary and mixed dentition caries exams and at least 2 diet diaries recorded between 5 and 8 years old (N=198). Using surface-specific transitions, combined counts of new cavitated caries (d(2-3)f and/or D(2-3)F) were determined from 4 primary second molars, 8 permanent incisors, and 4 permanent molars. Food and beverage intake frequencies were abstracted. Other factors were assessed using periodic questionnaires. Logistic regression identified predictors of new cavitated caries. RESULTS: Thirty-seven percent had new cavitated caries. The mean new cavitated caries count for all children was 1.17 surfaces (±2.28 SD). In multivariable logistic regression, the following were significantly associated (P<.10) with having new cavitated caries: noncavitated caries experience at 5 years old (odds ratio [OR]=2.67, P=.03); cavitated caries experience at 5 years old (OR=3.39, P=.004); greater processed starch at snack frequency (OR=3.87, P=.07); being older (OR=1.68, P=.04); and less frequent tooth-brushing (P=.001). CONCLUSION: Results suggested that increased tooth-brushing frequency and reduced consumption of processed starches as snacks may reduce caries incidence in younger school-aged children.

Tobacco-free community coalitions: opportunities for enhancing oral cancer prevention programs.

BACKGROUND: This study identified oral cancer (OC) education and tobacco reduction collaboration within tobacco-free community coalitions (TFCC). METHODS: Data from 4 TFCC were collected via educational intervention surveys and structured focused group Interviews. RESULTS: Of the 52 participants, 96% were aware that tobacco products are risk factors for OC, yet 33% were unaware of the high OC impact locally. About 90% agreed that primary care providers and dentists should provide OC screenings and tobacco cessation. CONCLUSION: There is a need for provider endorsement and public demand for OC screenings. Opportunity exists for partnering and collaborative OC prevention with TFCC.

Management of initial carious lesions: Iowa survey.

BACKGROUND: The authors explore Iowa dentists' agreement with the International Caries Classification and Management System (ICCMS) in the nonsurgical management of initial carious lesions in patients at low, moderate, and high caries risk and identify factors related to their agreement. METHODS: Electronic surveys were mailed to 916 actively practicing dentists who are alumni of the College of Dentistry at The University of Iowa. Questions included clinical scenarios that used text, clinical photographs, and radiographic images of initial carious lesions. Dentists were asked what type of treatment they would recommend. Treatment options included no treatment, nonsurgical treatment, or surgical treatment. Logistic regression analyses were used to assess associations among agreement with ICCMS, characteristics of the dentist's practice, and patients' caries risk level. RESULTS: A total of 138 Iowa dentists responded to the survey. Agreement with ICCMS regarding nonsurgical management of initial carious lesions for patients at low, moderate, and high risk levels were 73%, 59%, and 51% respectively. Compared with their counterparts, dentists who agreed with the recommendations for nonsurgical treatment were more likely to dry the teeth during caries detection (95% confidence interval [CI], 1.02 to 12.67, P = .0468), use magnification (95% CI, 1.16 to 7.17, P = .0225) for caries detection, have graduated less than 20 years ago (P = .0024), practice in public health settings (P = .0089), and perform a caries risk assessment (95% CI, 1.10 to 4.29, P = .0262). CONCLUSIONS: Dentists who dry teeth, use magnification for caries detection, graduated in the past 20 years, practice in a public health setting, and perform a caries risk assessment were significantly more likely to make decisions that were consistent with the guidelines of the ICCMS. PRACTICAL IMPLICATIONS: Knowledge of evidence-based options personalized for a patient's risk status is essential for applying the best management of initial caries lesions.

Masking and Penetration Ability of Various Sealants and ICON in Artificial Initial Caries Lesions In Vitro.

PURPOSE: The purpose of the present in vitro study and survey was to compare the masking ability and the penetration capacity of three resin composite sealers as well as a resin infiltrant in shallow artificial caries lesions. MATERIALS AND METHODS: Panels of artificial initial caries lesion with an average depth of 200 µm were created on buccal and lingual surfaces of 75 extracted human molars. Specimens were randomly assigned to 5 groups: ICON (DMG America), Biscover LV (Bisco), Optiguard (Kerr Hawe), Permaseal (Ultradent), and control (no treatment). Teeth were hemi-sectioned yielding two halves, each with a panel of artificial caries lesion. Lesions on one hemi-section were used to assess the esthetic improvement following caries lesion penetration with the 4 resins based on photographs evaluated using a 100-mm visual analogue scale (VAS) by 17 raters. Lesions on opposite hemi-sections were used to measure the resin penetration area percentage (PA%) and the resin penetration depth percentage (PD%) visualized using a confocal laser scanning microscope (CLSM, Leica). RESULTS: ICON, Optiguard, and Permaseal yielded significantly greater average VAS scores compared to Biscover. The mean PA% and PD% were significantly higher for ICON, intermediate for Optibond and Permaseal, and significantly lower for Biscover. A moderately large positive correlation was noticed between the average VAS scores and the penetration measures. CONCLUSION: All the resin sealers (Biscover, Optiguard, and Permaseal) penetrated the artificial initial caries lesions. However, ICON resulted in the deepest penetration and the largest penetration area percentages. The masking ability of Optiguard and Permaseal of the artificial caries lesions was similar to ICON.

Survival analysis of caries incidence in African-American school-aged children.

OBJECTIVES: To conduct an assessment of time-dependent covariates related to dental caries of the permanent dentition among a low socioeconomic status, understudied cohort of children, incorporating time-dependent covariates through the application of extended Cox proportional hazards modeling. METHODS: This study modeled the time to first cavitated dental caries in permanent teeth among school-aged children and assessed factors associated with this event. A cohort of 98 low socioeconomic status African-American children with mean age of 5.85 years at baseline was recruited in Uniontown, Alabama and followed prospectively for 6 years. None of these children had dental caries on permanent teeth at baseline, and oral examinations were performed annually. Caries-free survival curves were generated to describe time to event (having first decayed, filled, or missing permanent surface). Bivariate and multivariable extended Cox hazards modeling was used to assess the relationships between time-dependent and time-independent covariates and time to event. RESULTS: Twenty-eight children (28.6 percent) had their first permanent tooth caries event during the 6-year follow-up. Multivariable results showed that greater consumption of water was associated with lower dental caries hazard, while previous primary tooth caries experience was associated with greater dental caries hazard after adjustment for frequency of consumptions of milk, added-sugar beverages, and 100 percent juice. CONCLUSIONS: There was a global/overall significant caries protective effect of water consumption during the school-age period of child development.

Factors associated with dental caries experience in 1-year-old children.

OBJECTIVES: Dental caries in early childhood is an important public health problem. Previous studies have examined risk factors, but they have focused on children during the later stages of the disease process. The purpose of this study was to assess the factors associated with caries in children aged 6 to 24 months as part of a cross-sectional analysis. METHODS: Two hundred twelve mothers with children 6 to 24 months of age were recruited from Special Supplemental Nutrition Program for Women, Infants, and Children clinic sites in southeastern Iowa for participation in a longitudinal study of dental caries. Baseline assessments included detailed questions regarding the children's beverage consumption, oral hygiene, and family socioeconomic status. Dental caries examinations using the d(1)d(2-3)f criteria and semiquantitative assessments of salivary mutans streptococci (MS) levels of mother and child were also conducted. Counts of the number of teeth with visible plaque were recorded for maxillary and mandibular molars and incisors. RESULTS: Of the 212 child/mother pairs, 187 children had teeth. Among these children, the mean age was 14 months, and 23 of the children exhibited either d(1), d(2-3), or filled lesions. Presence of caries was significantly associated with older age, presence of MS in children, family income <$25,000 per year, and proportion of teeth with visible plaque. CONCLUSIONS: Results suggest that not only microbial measures, including MS and plaque levels, are closely associated with caries in very young children, but that other age-related factors may also be associated with caries. Continued study is necessary to more fully assess the risk factors for caries prevalence and incidence in preschool children.

Cariogenicity of soft drinks, milk and fruit juice in low-income african-american children: a longitudinal study.

BACKGROUND: The authors conducted a study to test the hypothesis that high consumption of soft drinks, relative to milk and 100 percent fruit juice, is a risk factor for dental caries in low-income African-American children in Detroit. METHODS: Trained dentists and interviewers examined a representative sample of 369 children, aged 3 to 5 years, in 2002-2003 and again two years later. The authors used the 2000 Block Kids Food Frequency Questionnaire (NutritionQuest, Berkeley, Calif.) to collect dietary information. They assessed caries by using the International Caries Detection and Assessment System. RESULTS: Soft drinks, 100 percent fruit juice and milk represented the sugared beverages consumed by the cohort. A cluster analysis of the relative proportion of each drink at baseline and follow-up revealed four consumption patterns. Using zero-inflated negative binomial models, the authors found that children who changed from being low consumers of soft drinks at baseline to high consumers after two years had a 1.75 times higher mean number of new decayed, missing and filled tooth surfaces compared with low consumers of soft drinks at both time points. CONCLUSION: Children who consumed more soft drinks, relative to milk and 100 percent fruit juice, as they grew older were at a greater risk of developing dental caries. CLINICAL IMPLICATIONS: Health promotion programs and health care providers should emphasize to patients and caregivers the caries risk associated with consumption of soft drinks.

Retrospective analysis of factors associated with the success of stepwise excavation procedure in deep carious lesions.

BACKGROUND: Recent scientific evidence regarding the stepwise excavation procedure (SWP) has not addressed the consideration of patient factors when selecting SWP as treatment for deep carious lesions (DCLs). This study assessed patient factors predicting a successful SWP defined as a tooth restored with SWP and did not result in root canal treatment or a dental extraction. METHODS: SWPs completed in 626 patients without symptomatic irreversible pulpitis at the University of Iowa College of Dentistry from January 2004 through December 2012 were evaluated. Patient demographic and tooth-specific characteristics were assessed in their relationship with the main outcome. RESULTS: SWPs had a 75% success rate when evaluated within 36 months of the initial treatment. Findings showed that patients who had successful SWP treatment of DCLs were somewhat younger than patients whose SWP treatment was not successful (mean age, 37.4 years and 40.5 years, respectively; odds ratio, 0.981; 95% confidence interval, 0.967 to 0.994; P = .0058). Patients who returned to their second appointment within 5 to 9 months were more likely to have a successful SWP treatment than those returning sooner than 5 months (odds ratio, 0.338; 95% confidence interval, 0.210 to 0.545; p < .0001). CONCLUSION: Treatment of deep carious lesions with SWP is effective for pulp preservation and patient age may influence the outcome. PRACTICAL IMPLICATIONS: Although a somewhat younger mean patient age was associated with successful treatment of DCLs, SWP can be successful regardless of patient age and clinicians should consider SWP in treating DCLs.

Dental caries and dietary patterns in low-income African American children.

PURPOSE: The purpose of this study was to assess the relationship between dietary patterns and dental caries severity in low-income African American children. METHODS: The participants were 3- to 5-year-old African American children in Detroit, Mich, with household incomes below 250% of the 2000 federal poverty level (N=436). Dietary intakes were obtained using the Block Kids Food Questionnaire. Dental caries in primary teeth were measured by the International Caries Detection and Assessment System criteria. The mean number of decoyed surfaces (noncavitated and cavitated, missing, and filled surfaces [dmfs]) for each child was estimated. Factor analysis was carried out to identify the patterns of solid food consumption. The resulting factor scores and drink variables were then used as covariates in multinomial logistic regression, with 4 levels of dmfs as the outcome. Statistical analyses were conducted using SAS and SUDAAN. RESULTS: Multinomial regression models found that age, soda consumption, and powdered/sport drink consumption were positively associated with dmfs scores. Milk and real juice (not orange) were associated with lower dmfs levels. CONCLUSIONS: Children frequently consume sugared drinks, which is associated with the prevalence of dental caries. Intervention programs that promote the adoption of noncariogenic dietary alternatives for children are needed.

Dental caries clusters among adolescents.

OBJECTIVES: There have been very few longitudinal studies of dental caries in adolescents, and little study of the caries risk factors in this age group. The purpose of this study was to describe different caries trajectories and associated risk factors among members of the Iowa Fluoride Study (IFS) cohort. METHODS: The IFS recruited a birth cohort from 1992 to 1995, and has gathered dietary, fluoride and behavioural data at least twice yearly since recruitment. Examinations for dental caries were completed when participants were ages 5, 9, 13 and 17 years. For this study, only participants with decayed and filled surface (DFS) caries data at ages 9, 13 and 17 were included (N=396). The individual DFS counts at age 13 and the DFS increment from 13 to 17 were used to identify distinct caries trajectories using Ward's hierarchical clustering algorithm. A number of multinomial logistic regression models were developed to predict trajectory membership, using longitudinal dietary, fluoride and demographic/behavioural data from 9 to 17 years. Model selection was based on the akaike information criterion (AIC). RESULTS: Several different trajectory schemes were considered, and a three-trajectory scheme-no DFS at age 17 (n=142), low DFS (n=145) and high DFS (n=109)-was chosen to balance sample sizes and interpretability. The model selection process resulted in use of an arithmetic average for dietary variables across the period from 9 to 17 years. The multinomial logistic regression model with the best fit included the variables maternal education level, 100% juice consumption, brushing frequency and sex. Other favoured models also included water and milk consumption and home water fluoride concentration. The high caries cluster was most consistently associated with lower maternal education level, lower 100% juice consumption, lower brushing frequency and being female. CONCLUSIONS: The use of a clustering algorithm and use of Akaike's Information Criterion (AIC) to determine the best representation of the data were useful means in presenting longitudinal caries data. Findings suggest that high caries incidence in adolescence is associated with lower maternal educational level, less frequent tooth brushing, lower 100% juice consumption and being female.

The cost-effectiveness of large amalgam and crown restorations over a 10-year period.

OBJECTIVE: To assist clinical decision making for an individual patient or on a community level, this study was done to determine the differences in costs and effectiveness of large amalgams and crowns over 5 and 10 years when catastrophic subsequent treatment (root canal therapy or extraction) was the outcome. METHODS: Administrative data for patients seen at the University of Iowa, College of Dentistry for 1735 large amalgam and crown restorations in 1987 or 1988 were used. Annual costs and effectiveness values were calculated. Costs of initial treatment (large amalgam or crown), and future treatments were determined, averaged and discounted. The effectiveness measure was defined as the number of years a tooth remained in a state free of catastrophic subsequent treatment. Years free of catastrophic treatment were averaged, and discounted. The years free of catastrophic treatment accounted for individuals who dropped out or withdrew from the study. RESULTS: Teeth with crowns had higher effectiveness values at a much higher cost than teeth restored with large amalgams. The cost of an addition year free of catastrophic treatment for crowns was 1088.41 dollars at 5 years and 500.10 dollars at 10 years. Teeth in women had more favorable cost-effectiveness ratios than those in men, and teeth in the maxillary arch had more favorable cost-effectiveness ratios than teeth in the mandibular arch. CONCLUSIONS: Neither the large amalgam or crown restoration had both the lowest cost and the highest effectiveness. The higher incremental cost-effectiveness ratio for crowns should be considered when making treatment decisions between large amalgam and crown restorations.

Timing of primary tooth emergence among U.S. racial and ethnic groups.

OBJECTIVES: To compare timing of tooth emergence among groups of American Indian (AI), Black and White children in the United States at 12 months of age. METHODS: Data were from two sources - a longitudinal study of a Northern Plains tribal community and a study with sites in Indiana, Iowa and North Carolina. For the Northern Plains study, all children (n = 223) were American Indian, while for the multisite study, children (n = 320) were from diverse racial groups. Analyses were limited to data from examinations conducted within 30 days of the child's first birthday. RESULTS: AI children had significantly more teeth present (Mean: 7.8, Median: 8.0) than did Whites (4.4, 4.0, P < 0.001) or Blacks (4.5, 4.0, P < 0.001). No significant differences were detected between Black and White children (P = 0.58). There was no significant sex difference overall or within any of the racial groups. CONCLUSIONS: Tooth emergence occurs at a younger age for AI children than it does for contemporary White or Black children in the United States.