Library

Notes: Objectives: This paper presents data on the prevalence of primary tooth fluorosis among children residing in Iowa, and the relationships between fluorosis prevalence and selected measures of fluoride exposures. Methods: Children in the study cohort were followed prospectively during the first year of life. This study assessed their home water fluoride concentrations and use of fluoride dentifrice or dietary fluoride supplements. A total of 637 children (320 females and 317 males) were examined for fluorosis using a modification of the TSIF index at age 4 1/2 to 5 years, with 90.4 percent having intact primary dentitions. Results: 74 children (11.6%) had fluorosis present on one or more of their primary teeth, and 71 children (11.1%) had two or more teeth affected. Nearly all fluorosis was mild, with the primary second molar teeth most commonly affected. Fluorosis was significantly associated with higher water fluoride concentration, but not with the use of dentifrice or fluoride supplements. Conclusions: The results of this study show that primary tooth fluorosis is relatively uncommon, but is most frequently seen on the posterior teeth, particularly the primary second molars, which form at later stages of development. This finding suggests that primary tooth fluorosis is mostly a postnatal phenomenon, and is associated with higher water fluoride levels.

Notes: Objective: Decisions to extract a tooth may be among the most critical in dentistry. The aim of this study was to prospectivety investigate both clinical and nonclinical factors related to decisions to extract or retain teeth in private general dental practice. Methods: A convenience sample of 196 Iowa dentists in private general dental practice reported on 549 cases where decisions were made to extract or retain teeth as they occurred in their practices during a one-month period in May 1997. Bivariate and multivariate analyses were used to identify factors that differentiated between cases where a tooth (or teeth) was extracted and cases where an at-risk tooth was retained. Results: Of the 549 cases, 67 percent involved extraction, while the remainder involved alternatives to extraction. In comparing extraction cases to alternative treatment cases, we excluded 150 extraction cases because dentists reported that no alternative to extraction was available. Using Generalized Estimating Equations (GEE), we identified cost of treatment, presence of tooth mobility, poor prognosis of alternative treatment, and presence of gross caries as significant factors associated with extraction, while previous treatment of the tooth and concerns with patients' health were significantly associated with alternatives to extraction. Conclusions: For teeth at risk for extraction, cost, substantial periodontal disease, and several clinical factors were predictive of extraction.

Notes: Objective: This study compared time required and 12-month retention for two methods of sealant placement: traditional acid-etch technique and air-abrasion technique without acid etch. Methods: Sealants were placed on the permanent first molars of 84 children in grades 1–4 who were randomly assigned to treatment groups. All sealants were placed in a school setting by the same clinician. Chair time required for sealant placement was recorded, and retention rates were determined for each technique 12 months after placement. Results: Mean chair time for placement of sealants on four first molars using the air-abrasion technique was significantly less than for the acid-etch technique (7:36 minutes vs 10:56 minutes). Fifty-eight children were available at 12-month follow-up; an examiner not involved in sealant placement and masked as to the technique used determined retention. Rates of complete retention for occlusal surfaces were not significantly different for the two techniques, although the rate for acid etch was higher than that for air abrasion (95% vs 87%). The complete retention rates for the acid-etch technique were significantly higher than air abrasion for buccal and distolingual surfaces. These rates were 65 percent and 58 percent, respectively, for acid etch and 6 percent and 28 percent, respectively, for air abrasion. Conclusion: Although more research is needed to improve air-abrasion applications, it does not appear that air abrasion without acid etching offers a significant advantage over traditional sealant placement methods and, in fact, appears to be inferior to the acid-etch technique for use in public health settings.

Notes: Background: Dental caries in the primary dentition has received renewed attention in recent years because caries in the primary dentition is predictive of later canes experience, and because of efforts to address early childhood caries. More detailed caries diagnostic criteria have been developed and used for the permanent teeth; however, such criteria have not been widely adopted for caries diagnosis in the primary dentition. Methods: As part of the Iowa Fluoride Study, caries diagnostic criteria were developed specifically for the primary teeth. The criteria included noncavitated (d1) lesions and cavitated (d2–3) lesions. Examinations were conducted on 698 children in the primary dentition by two trained examiners who did duplicate examinations on 11 percent (n=67) of these children. Results: Interexaminer agreement for any dl and any d2–3 lesions at the person level was 100 percent. At the tooth level for d1d2–3 there was 98.5 percent agreement and kappa was .91. For d1 at the tooth level, agreement was 97.0 percent agreement and kappa=.24. For d2–3 it was 99.4 percent agreement and kappa=.81. Prevalence of untreated d2–3 was 16.5 percent, while that of d1 was 24.1 percent. Nearly 73 percent had no d2–3 or filled surfaces, while over 63 percent had no (d1, d2–3, or filled surfaces. Decay experience was most common on the primary second molars. About 56 percent of untreated d2–3 decay was located in the pits and fissures, while 58 percent of d1 decay was located on smooth surfaces. Conclusion: Despite some concern with reliability of diagnosing dl lesions, it appears that the d1d 2–3 criteria are informative and useful in assessing the primary dentition.

Notes: Objectives: Dental fluorosis prevalence has increased in the United States, Canada, and other nations due to the widespread availability of fluoride in many forms, with fluoride ingestion during the first three years of life appearing most critical in fluorosis etiology. With few contemporary studies of fluoride ingestion in this age group, the purpose of this paper is to describe patterns of estimated fluoride ingestion from birth to 36 months of age from water, dentifrice, and dietary fluoride supplements and combined. Methods: Repeated responses to separate series of questions about water intake, use of fluoride dentifrice, and use of fluoride supplements were collected by questionnaire as part of the longitudinal Iowa Fluoride Study and used to estimate fluoride intake. Estimated intake is reported by source and combined at different ages. Effects of subject age and other covariates on fluoride intake were assessed using regression methods appropriate for the analysis of correlated data. Results: For most children, water fluoride intake was the predominant source, especially through age 12 months. Combined daily fluoride intake increased through 9 months, was lower at 12 and 16 months, and increased again thereafter. Mean intake per unit body weight (bw) was about 0.075 mg F/kg bw through 3 months of age, 0.06 mg F/kg bw at 6 and 9 months, 0.035 mg F/kg bw at 12 and 16 months, and 0.043 mg F/kg bw from 20–36 months. Depending on the threshold chosen (e.g., 0.05 or 0.07 mg F/kg bw), variable percentages of the children exceeded the levels, with percentages greatest during the first 9 months. Regression analyses showed fluoride intake (mg F/kg bw) from 1.5–9 months to decrease with increasing child's age, mother's age, and mother's education, with a complex three-way interaction among these factors. From 12–20 months, fluoride intake increased with increasing child age and decreased with increasing mother's age. No statistically significant relation-ships were found for fluoride intake from 24–36 months. Conclusions: There is considerable variation in fluoride intake across ages and among individuals. Longitudinal studies may be necessary to fully understand the relationships between fluoride ingestion over time and development of fluorosis.