Addition of Povidone-Iodine to Fluoride Varnish for Dental Caries: A Randomized Clinical Trial.

INTRODUCTION: Dental caries is the most common chronic childhood disease. Products of metabolism by bacteria populating the tooth surface induce development and progression of cavities. OBJECTIVES: We sought to determine whether a polyvinylpyrrolidone-iodine (PVP-I; povidone-iodine) and NaF topical varnish was superior to one containing only NaF in prevention of new dental caries lesions in a single-center randomized active-controlled trial based on a double-blind, parallel-group design. METHODS: The site was Pohnpei State, Federated States of Micronesia. The study population was healthy children 49 to 84 mo old who were enrolled in early childhood education: 284 were randomized (1:1 allocation), and 273 were included in year 1 analysis and 262 in year 2. The test varnish contained 10% PVP-I and 5.0% NaF. The comparator contained only 5.0% NaF but was otherwise identical. Varnishes were applied every 3 mo during 2 y. The primary outcome was the surface-level primary molar caries lesion increment (d2-4mfs) at 2 y. Caries lesion increments from baseline to year 1 and year 2 were compared between conditions with log-linear regression, adjusting for age and sex and whether the tooth was sound at baseline (free of caries lesions). RESULTS: At year 1, the caries lesion increment for primary molars sound at baseline was 0.9 surfaces (SD = 1.5) for the test varnish versus 1.8 (SD = 2.2) for the comparator varnish with fluoride alone (adjusted rate ratio, 0.50; 95% CI, 0.31 to 0.81; P = .005). At year 2, the caries lesion increment for primary molars sound at baseline was 2.3 surfaces (SD = 2.8) for the test varnish as compared with 3.3 (SD = 2.7) for the comparator (adjusted rate ratio, 0.74; 95% CI, 0.52 to 1.03; P = .073). Teeth that were already cavitated at baseline did not show a preventive effect. There were no harms. CONCLUSIONS: A dental varnish containing PVP-I and NaF is effective in the primary prevention of cavities in the primary dentition (NCT03082196). KNOWLEDGE TRANSFER STATEMENT: This study demonstrates that periodic application of a varnish containing NaF and PVP-I is effective in prevention of caries lesions and useful in assessing the potential of combined treatment.

Supply of care by dental therapists and emergency dental consultations in Alaska native communities in the Yukon-Kuskokwim delta: a mixed methods evaluation.

OBJECTIVES: Examine the relationship between supply of care provided by dental therapists and emergency dental consultations in Alaska Native communities. METHODS: Explanatory sequential mixed-methods study using Alaska Medicaid and electronic health record (EHR) data from the Yukon-Kuskokwim Health Corporation (YKHC), and interview data from six Alaska Native communities. From the Medicaid data, we estimated community-level dental therapy treatment days and from the EHR data we identified emergency dental consultations. We calculated Spearman partial correlation coefficients and ran confounder-adjusted models for children and adults. Interview data collected from YKHC providers (N=16) and community members (N=125) were content analysed. The quantitative and qualitative data were integrated through connecting. Results were visualized with a joint display. RESULTS: There were significant negative correlations between dental therapy treatment days and emergency dental consultations for children (partial rank correlation = -0.48; p⟨0.001) and for adults (partial rank correlation = -0.18; p=0.03). Six pediatric themes emerged: child-focused health priorities; school-based dental programs; oral health education and preventive behaviors; dental care availability; healthier teeth; and satisfaction with care. There were four adult themes: satisfaction with care; adults as a lower priority; difficulties getting appointments; and limited scope of practice of dental therapy. CONCLUSIONS: Alaska Native children, and to a lesser extent adults, in communities served more intensively by dental therapists have benefitted. There are high levels of unmet dental need as evidenced by high emergency dental consultation rates. Future research should identify ways to address unmet dental needs, especially for adults.

Organizational Readiness to Implement System Changes in an Alaskan Tribal Dental Care Organization.

INTRODUCTION: Tribal health care systems are striving to implement internal changes to improve dental care access and delivery and reduce health inequities for American Indian and Alaska Native children. Within similar systems, organizational readiness to implement change has been associated with adoption of system-level changes and affected by organizational factors, including culture, resources, and structure. OBJECTIVES: The objectives of this study were to assess organizational readiness to implement changes related to delivery of evidence-based dental care within a tribal health care organization and determine workforce- and perceived work environment-related factors associated with readiness. METHODS: A 92-item questionnaire was completed online by 78 employees, including dental providers, dental assistants, and support staff (88% response rate). The questionnaire queried readiness for implementation (Organizational Readiness for Implementing Change), organizational context and resources, workforce issues, organizational functioning, and demographics. RESULTS: Average scores for the change commitment and change efficacy domains (readiness for implementation) were 3.93 (SD = .75) and 3.85 (SD = .80), respectively, where the maximum best score was 5. Perceived quality of management, a facet of organizational functioning, was the only significant predictor of readiness to implement change (B = .727, SE = .181, P < .0002) when all other variables were accounted for. CONCLUSION: Results suggest that when staff members (including dentists, dental therapists, hygienists, assistants, and support staff) from a tribal health care organization perceive management to be high quality, they are more supportive of organizational changes that promote evidence-based practices. Readiness-for-change scores indicate an organization capable of institutional adoption of new policies and procedures. In this case, use of more effective management strategies may be one of the changes most critical for enhancing institutional behaviors to improve population health and reduce health inequities. KNOWLEDGE TRANSFER STATEMENT: The results of this study can be used by clinicians and other leaders implementing changes within dental care organizations. To promote organizational readiness for change and, ultimately, more expedient and efficient adoption of system-level changes by stakeholders, consideration should be given to organizational functioning generally and quality of management practices specifically.

Implementation partnerships in a community-based intergenerational oral health study.

BACKGROUND: University-community partnerships are a common strategy used in implementing community-based health promotion trials, yet few published studies report these interactions in detail. "Baby Smiles" was a five-year intervention study in Oregon, USA. The study involved 400 low-income women during and after pregnancy across four rural counties. In this report, we describe and assess four university-community health partnerships formed to support the intervention. METHODS: A community health partnership advisory group for the study was established in each of the four participating counties. Group membership ranged from 9 to 23 individuals. A survey was administered to the groups five times in a 2.5 year period. The survey asked members' opinions of the intervention's goals, scientific basis and relevance to their organisation. Questions also asked about members' knowledge of oral health, beliefs about access to dental care for low-income pregnant women and children in their county and how their organisation functioned. RESULTS: There was strong overall support by each partnership group despite differences in the groups' structure, foci and turnover in membership during intervention period. Responses to specific survey items indicating misinformation or negative opinions about oral health care were used to address weaknesses in study implementation throughout the conduct of the study. CONCLUSION: Systematic monitoring of community support for a multi-year oral health intervention is feasible and can identify potential barriers to address while the study is underway.

Comparison of CaOH with MTA for direct pulp capping: a PBRN randomized clinical trial.

This practice-based, randomized clinical trial evaluated and compared the success of direct pulp capping in permanent teeth with MTA (mineral trioxide aggregate) or CaOH (calcium hydroxide). Thirty-five practices in Northwest PRECEDENT were randomized to perform direct pulp caps with either CaOH (16 practices) or MTA (19 practices). Three hundred seventy-six individuals received a direct pulp cap with CaOH (n = 181) or MTA (n = 195). They were followed for up to 2 yrs at regular recall appointments, or as dictated by tooth symptoms. The primary outcomes were the need for extraction or root canal therapy. Teeth were also evaluated for pulp vitality, and radiographs were taken at the dentist's discretion. The probability of failure at 24 mos was 31.5% for CaOH vs. 19.7% for MTA (permutation log-rank test, p = .046). This large randomized clinical trial provided confirmatory evidence for a superior performance with MTA as a direct pulp-capping agent as compared with CaOH when evaluated in a practice-based research network for up to 2 yrs.

The short-term effects of diammine silver fluoride on tooth sensitivity: a randomized controlled trial.

Tooth sensitivity is a common clinical problem. This multi-center randomized clinical trial assessed the effectiveness and safety of topical diammine silver fluoride. From two sites (Lima and Cusco, Peru), 126 adults with at least one tooth sensitive to compressed air were randomly assigned to either the experimental treatment or sterile water, and pain was assessed by means of a 100-mm visual analogue scale at 24 hours and 7 days. The diammine silver fluoride reduced pain at 7 days at both sites. At the Lima site, the average change in pain scores between baseline and day 7 for the silver fluoride group was -35.8 (SD = 27.7) mm vs. 0.4 (SD = 16.2) mm for the control group (P < 0.001). In Cusco, the average change in pain scores for the silver fluoride group was -23.4 (SD = 21.0) mm and -5.5 (18.1) mm for the control group (P = 0.002). No tissue ulceration, white changes, or argyria was observed. A small number of participants in the silver fluoride group experienced a mild but transient increase in erythema in the gingiva near the tooth. No changes were observed in the Gingival Index. We concluded that diammine silver fluoride is a clinically effective and safe tooth desensitizer.

Immunization of Macaca fascicularis against experimental periodontitis using a vaccine containing cysteine proteases purified from Porphyromonas gingivalis.

INTRODUCTION: Periodontitis is a common infectious disease to which Porphyromonas gingivalis has been closely linked, in which the attachment tissues of the teeth and their alveolar bone housing are destroyed. We conducted a study to determine if immunization using a purified antigen could alter the onset and progression of the disease. METHODS: Using the ligature-induced model of periodontitis in Macaca fascicularis, we immunized five animals with cysteine protease purified from P. gingivalis and used an additional five animals as controls. Alveolar bone loss was measured by digital subtraction radiography. RESULTS: Immunization induced high titers of specific immunoglobuin G serum antibodies that were opsonic. Total bacterial load, levels of P. gingivalis in subgingival plaque and levels of prostaglandin E(2) in gingival crevicular fluid were significantly reduced. Onset and progression of alveolar bone loss was inhibited by approximately 50%. No manifestations of toxicity were observed. CONCLUSIONS: Immunization using a purified protein antigen from P. gingivalis inhibits alveolar bone destruction in a ligature-induced periodontitis model in M. fascicularis.

Efficiency issues among statistical methods for demonstrating efficacy of caries prevention.

Although repeated tooth-surface-specific information is commonly collected during a longitudinal caries clinical trial, traditional methods often make limited use of the repeated measures. Newer methods of analysis, such as methods based on time-to-event and methods for longitudinal or clustered data, have the potential to increase the efficiency of the statistical analysis. We compare a range of analytical methods from the traditional analysis based only on the number of caries onsets to newer methods that incorporate time at risk and surface-specific information, such as Poisson regression methods for clustered data, with respect to the efficiency of treatment comparisons. Under most circumstances, the greatest gain in efficiency associated with time-to-event methods will be due to the ability of subjects to contribute caries onsets to the analysis until they are lost from the study. Incorporating the number of surfaces at risk, the surface time at risk, and surface-specific characteristics will typically produce only a modest gain in efficiency.

Overbite and overjet are not related to self-report of temporomandibular disorder symptoms.

Overbite and overjet, especially high or low values, have been found in some studies to be associated with temporomandibular disorders (TMD). This study evaluates the relationship between overbite/overjet and three TMD self-report measures (pain, joint noises, limited mouth-opening). Subjects were from two population-based cross-sectional studies (3033 subjects). After adjustment for age and gender, high or low values of overbite were not associated with an increased risk of self-reported TMD pain as compared with a reference category of a normal overbite of 2 to 3 mm (-8 to -1 mm, odds ratio = 0.36, 95% confidence interval = 0.05-2.76; 6 to 15 mm, odds ratio = 1.08, 95% confidence interval = 0.68-1.72). Similar non-significant results were found for overjet and TMD pain, and for the association of overjet/overbite and joint noises or limited mouth-opening. This study provides the strongest evidence to date that there is no association between overbite or overjet and self-reported TMD.

Single-nucleotide polymorphisms and haplotype analysis in beta-defensin genes in different ethnic populations.

Beta-defensins are cationic antimicrobial peptides expressed by epithelial cells and exhibit antibacterial, antifungal, and antiviral properties. The defensins are part of the innate host defense network and may have a significant protective role in the oral cavity and other mucosa. Defects or alteration in expression of the beta-defensins may be associated with susceptibility to infection and mucosal disorders. We examined the occurrence of single-nucleotide polymorphisms (SNPs) in the human beta-defensin genes DEFB1 and DEFB2 encoding human beta-defensin-1 and -2 (hBD-1, hBD-2), respectively, in five ethnic populations and defined haplotypes in these populations. Fifteen SNPs were identified in both DEFB1 and DEFB2. Coding region SNPs were found in very low frequency in both genes. One nonsynonymous DEFB1 SNP, G1654A (Val --> Ile), and one nonsynonymous DEFB2 SNP, T2312A (Leu --> His), were identified. Seven sites in each gene exhibited statistically significant differences in frequency between ethnic groups, with the greatest variation in the promoter and in the 5'-untranslated region of DEFB1. DEFB1 displayed 10 common haplotypes, including one cosmopolitan haplotype. Eight common haplotypes were found in DEFB2, including one cosmopolitan haplotype shared among all five ethnic groups. Our results show that genotypic variability among ethnic groups will need to be addressed when performing associative genetic studies of innate defense mechanisms and susceptibility to disease.

Human auditory brainstem response to temporal gaps in noise.

Gap detection is a commonly used measure of temporal resolution, although the mechanisms underlying gap detection are not well understood. To the extent that gap detection depends on processes within, or peripheral to, the auditory brainstem, one would predict that a measure of gap threshold based on the auditory brainstem response (ABR) would be similar to the psychophysical gap detection threshold. Three experiments were performed to examine the relationship between ABR gap threshold and gap detection. Thresholds for gaps in a broadband noise were measured in young adults with normal hearing, using both psychophysical techniques and electrophysiological techniques that use the ABR. The mean gap thresholds obtained with the two methods were very similar, although ABR gap thresholds tended to be lower than psychophysical gap thresholds. There was a modest correlation between psychophysical and ABR gap thresholds across participants. ABR and psychophysical thresholds for noise masked by temporally continuous, high-pass, or spectrally notched noise were measured in adults with normal hearing. Restricting the frequency range with masking led to poorer gap thresholds on both measures. High-pass maskers affected the ABR and psychophysical gap thresholds similarly. Notched-noise-masked ABR and psychophysical gap thresholds were very similar except that low-frequency, notched-noise-masked ABR gap threshold was much poorer at low levels. The ABR gap threshold was more sensitive to changes in signal-to-masker ratio than was the psychophysical gap detection threshold. ABR and psychophysical thresholds for gaps in broadband noise were measured in listeners with sensorineural hearing loss and in infants. On average, both ABR gap thresholds and psychophysical gap detection thresholds of listeners with hearing loss were worse than those of listeners with normal hearing, although individual differences were observed. Psychophysical gap detection thresholds of 3- and 6-month-old infants were an order of magnitude worse than those of adults with normal hearing, as previously reported; however, ABR gap thresholds of 3-month-old infants were no different from those of adults with normal hearing. These results suggest that ABR gap thresholds and psychophysical gap detection depend on at least some of the same mechanisms within the auditory system.

Comparisons of Yupik infant growth measurements with NCHS/CDC reference data.

The National Center for Health Statistics/Centers for Disease Control and Prevention growth reference is routinely used to monitor Yupik infant growth although Yupiks are ethnically different from the population from which the reference was developed. To clarify interpretation of Yupik infant growth data for clinical practice and public health assessment, Yupik infant growth measurements were compared with this reference. From 1990 through 1992 a convenience survey of 555 Yupik infants was completed in pediatric clinics in the Yukon Kuskokwim Delta region of Alaska. Data was analyzed using Z-score distributions of height-for-age, weight-for-age, and weight-for-height and head circumference-for-age percentiles based on the growth reference. At birth, Yupik neonates had significantly greater height-for-age and weight-for-age than the National Center for Health Statistics/Centers for Disease Control and Prevention reference. Between 1 and 12 months, Yupik infants had significantly greater weight-for-age, weight-for-height, and head circumference-for-age than the growth reference.

The roles of beliefs, catastrophizing, and coping in the functioning of patients with temporomandibular disorders.

Pain-related beliefs, catastrophizing, and coping have been shown to be associated with measures of physical and psychosocial functioning among patients with chronic musculoskeletal and rheumatologic pain. However, little is known about the relative importance of these process variables in the functioning of patients with temporomandibular disorders (TMD). To address this gap in the literature, self-report measures of pain, beliefs, catastrophizing, coping, pain-related activity interference, jaw activity limitations, and depression, as well as an objective measure of jaw opening impairment, were obtained from 118 patients at a TMD specialty clinic. Controlling for age, gender, and pain intensity, significant associations were found between (1) pain beliefs and activity interference, depression, and non-masticatory jaw activity limitations, (2) catastrophizing and activity interference, depression, and non-masticatory jaw activity limitations, and (3) coping and activity interference and depression. Controlling for age, gender, pain intensity, and the other process variables, significant associations were found between (1) beliefs and activity interference and depression, and (2) catastrophizing and depression. No process variable was associated significantly with the objective measure of jaw impairment. The results suggest that for patients with moderate or high levels of TMD pain and dysfunction, beliefs about pain play an important role in physical and psychosocial functioning.

A covariance estimator for GEE with improved small-sample properties.

In this paper, we propose an alternative covariance estimator to the robust covariance estimator of generalized estimating equations (GEE). Hypothesis tests using the robust covariance estimator can have inflated size when the number of independent clusters is small. Resampling methods, such as the jackknife and bootstrap, have been suggested for covariance estimation when the number of clusters is small. A drawback of the resampling methods when the response is binary is that the methods can break down when the number of subjects is small due to zero or near-zero cell counts caused by resampling. We propose a bias-corrected covariance estimator that avoids this problem. In a small simulation study, we compare the bias-corrected covariance estimator to the robust and jackknife covariance estimators for binary responses for situations involving 10-40 subjects with equal and unequal cluster sizes of 16-64 observations. The bias-corrected covariance estimator gave tests with sizes close to the nominal level even when the number of subjects was 10 and cluster sizes were unequal, whereas the robust and jackknife covariance estimators gave tests with sizes that could be 2-3 times the nominal level. The methods are illustrated using data from a randomized clinical trial on treatment for bone loss in subjects with periodontal disease.

Identification of neonatal hearing impairment: hearing status at 8 to 12 months corrected age using a visual reinforcement audiometry protocol.

OBJECTIVES: 1) To describe the hearing status of the at-risk infants in the National Institutes of Health-Identification of Neonatal Hearing Impairment study sample at 8 to 12 mo corrected age (chronologic age adjusted for prematurity). 2) To describe the visual reinforcement audiometry (VRA) protocol that was used to obtain monaural behavioral data for the sample. DESIGN: All neonatal intensive care unit infants and well babies with risk factors (including well babies who failed neonatal tests) were targeted for follow-up behavioral evaluation once they had reached 8 mo corrected age. Three thousand one hundred and thirty-four (64.4%) of the 4868 surviving infants returned for at least one behavioral hearing evaluation, which employed a well-defined VRA protocol. VRA thresholds or minimum response levels (MRLs) were determined for speech and pure tones of 1.0, 2.0, and 4.0 kHz for each ear using insert earphones. RESULTS: More than 95% of the infants were reliably tested with the VRA protocol; 90% provided complete tests (four MRLs for both ears). Ninety-four percent of the at-risk infants were found to have normal hearing sensitivity (MRLs of 20 dB HL) at 1.0, 2.0, and 4.0 kHz in both ears. Of the infants, 2.2% had bilateral hearing impairment, and 3.4% had impairment in one ear only. More than 80% of the impaired ears had losses of mild-to-moderate degree. CONCLUSIONS: This may be the largest study to attempt to follow all at-risk infants with behavioral audiometric testing, regardless of screening outcome, in an effort to validate the results of auditory brain stem response, distortion product otoacoustic emission, and transient evoked otoacoustic emission testing in the newborn period. It is one of only a few studies to report hearing status of infants at 1 yr of age, using VRA on a clinical population. Successful testing of more than 95% of the infants who returned for the VRA follow-up documents the feasibility of obtaining monaural behavioral data in this population.

Between-subject and within-subject statistical information in dental research.

The evaluation of risk factors in dental research frequently uses observations at multiple sites in the same patient. For this reason, statistical methods that accommodate correlated data are generally used to assess the significance of the risk factors (e.g., generalized estimating equations, generalized linear mixed models). In applications of these methods, it is typically assumed (implicitly, if not explicitly) that between-subject and within-subject comparisons will produce the same estimated effect of the risk factor. When between- and within-subject comparisons conflict, the statistical methods can give biased estimates or results that are difficult to interpret. For illustration, we present two examples from periodontal disease studies in which different statistical methods give different estimates and significance levels for a risk factor. Statistical analyses in dental research should assess whether different sources of information give similar conclusions about risk factors or treatments.

Effectiveness of local anesthesia in pediatric dental practice.

BACKGROUND: Pain control in dental treatment for children is very important. The purpose of this study is to describe the characteristics of local anesthetic use by pediatric dentists and to examine factors related to its effectiveness in children. METHODS: The authors observed 361 patients in 17 pediatric dental practices in Washington state while each child received restorative or surgical dental treatment. The authors recorded data concerning local anesthetic use and effectiveness. The children's mean age was 87 months, and 181 (50.1 percent) of the patients were girls. A pediatric dentist observer rated each child's anxiety before the initial injection of local anesthetic and the effectiveness of pain control during restorative treatment. The observing dentist asked the treating dentist about the effectiveness of pain control after completion of treatment. RESULTS: Forty-two of 361 children (11.6 percent) were observed to experience ineffective pain control. Fourteen of 17 dentists (82.4 percent) were observed to have at least one patient in whom pain control was ineffective. Lidocaine (2 percent with 1:100,000 epinephrine) was used by 15 of 17 dentists (88.2 percent) and in 312 of 361 cases (86.4 percent). The average amount of agent was one cartridge (36 milligrams of lidocaine). Children who were anxious, who had symptoms before treatment, and who underwent more invasive operative and endodontic procedures were more likely to experience ineffective pain control. CONCLUSIONS: The data suggest that painful treatment is relatively frequent even in specialized pediatric practice. Variability in general practice is likely to be greater. CLINICAL IMPLICATIONS: The incidence of ineffective pain control may be less if clinicians use methods to reduce anxiety and perioperative infection and symptoms.

Antigenic variation and cross-reactivity in Bacteroides forsythus clinical isolates detected by western blot.

Bacteroides forsythus is one of the etiologic agents of destructive periodontal diseases. Determining which antigenic components of the bacterium are recognized in the immune response of periodontitis patients is an important step in assessing strategies for vaccine development. The aim of this study was to identify the major strain-variable and cross-reactive antigens of B. forsythus clinical isolates recognized by serum IgG from patients with early-onset rapidly progressive periodontitis. Ten patient sera with measurable IgG against antigenic components of the species were identified by Western blot. Positive sera were tested by checkerboard ELISA to identify those most responsive to strain-variable antigens in nine clinical isolates and ATCC strain 43037. Correlation analysis of the ELISA data suggested that different subsets of isolates were preferentially recognized by different sera. Western blots revealed that certain sera also recognized major shared components across all the isolates, but preferential recognition of different isolate subsets by different patients was clearly confirmed. To determine if the variable antigens recognized were nonprotein, proteinase K-digested isolates were compared to undigested controls by Western blot. The main strain-variable antigens were proteinase resistant, while proteins at 200 and 210 kDa were identified as the major shared components. Two-dimensional SDS-PAGE revealed that these proteins are the quantitatively dominant heat-modifiable components of the cell envelope. Even though variable antigens are prominent in the immune response of patients, a cross-protective vaccine based on the shared envelope proteins of B. forsythus seems feasible in light of these observations.

Antigenic variation in Bacteroides forsythus detected by a checkerboard enzyme-linked immunosorbent assay.

Evidence indicating that multiple serotypes of Bacteroides forsythus participate in rapidly progressing periodontal infections has not been reported previously. Our aim was to develop an assay for detecting subsets of B. forsythus clinical isolates which differ in serogroup membership and subsets of patients with immunoglobulin G (IgG) responses which differ in serogroup recognition. A checkerboard enzyme-linked immunosorbent assay (ELISA) was used to assess variation in the IgG binding profiles of 22 clinical isolates in sera from 28 patients with early-onset rapidly progressive periodontitis. To accommodate the maximum number of isolates and sera in a given assay run, a multiplate assay grid with standard 96-well microtest plates was established. Single dilutions of individual sera were placed in rows crossing columns of isolate-coated wells, and antigen-specific IgG immobilized in the wells was measured as ELISA absorbance. Pooled sera and isolates were assayed in parallel to serve as negative controls for variation in IgG binding profiles. Correlation and hierarchical cluster analysis of the absorbance data matrix showed that the isolates could be sorted into at least four clusters based on variations in their IgG binding profiles across different sera. Furthermore, at least two patient clusters were defined by variations in their serum IgG antigen recognition profiles across different isolates. We conclude that multiple serogroups of B. forsythus exist and that different serogroups are dominant in the antibody response of different patients. The method applied here could be used to serologically classify clinical isolates of other species which evoke a serum antibody response in patients.

An explanatory model of the dental care utilization of low-income children.

OBJECTIVES: Factors related to the utilization of dental care by 5- to 11-year-old children from low-income households were investigated using a comprehensive multivariate model that assessed the contribution of structure, history, cognition, and expectations. The influence of dentist-patient interactions, psychosocial and health beliefs, particularly fear of the dentist, on utilization were investigated. METHODS: Children were chosen randomly from public schools, and 895 mothers were surveyed and their children were interviewed in the home. Utilization was studied during the 1991-1992 school year, including a 6-month follow-up period after the interview. RESULTS: The overall utilization rate was 63.2%, and the rate for nonemergent (preventive) visits was 59.9%. Utilization was unrelated to actual oral health status. Race and years the guardian lived in the United States were predictive of an episode of care. Preventive medical visits and perceived need were strong predictors of a visit to the dentist, as were beliefs in the efficacy of dental care. Mothers who were satisfied with their own care and oral health and whose children were covered by insurance were more likely to utilize children's dental care. In contrast, child dental fear and absences from school for family problems were associated with lower rates of utilization. CONCLUSIONS: Mutable factors that govern the use of care in this population were identified. These findings have implications for the design of dental care delivery systems for children and their families.