In total, 742 Study members completed the dental questionnaire at all three ages. SES data were not available for one Study member, and this individual was excluded from the analysis, leaving a total of 741 (72.7% of the surviving cohort at age 26 yrs). Unless otherwise specified, all subsequent analyses are based on this group. There were higher proportions of low-SES individuals and smokers among the excluded Study members (P < 0.05; ).
Characteristics of Study Members Who Completed the Dental Questionnaire at 15, 18, and 26 yrs Compared with Those Who Missed One or More Years
Unfavorable beliefs were most prevalent regarding the importance of fluoridated water, use of dental floss, or the avoidance of sweet foods (). The mean number of stable favorable beliefs held by females was significantly greater than for males (). The greatest stability was associated with ‘keeping the teeth and gums very clean’, with only 6.1% of Study members changing their views over time, while the least stability was associated with ‘drinking fluoridated water’, with 52.4% changing their beliefs.
Dental Beliefs Endorsed by Study Members at Ages 15, 18, and 26 yrs
Stability of Dental Beliefs Endorsed by Study Members, with Comparisons by Gender
The proportion of Study members holding stable favorable oral-health-related beliefs was marginally greater among those of high SES, non-smokers, and those who had spent all their lives living in fluoridated areas. These associations were not significant. A significant association existed between beliefs and dental visiting patterns, however, with individuals holding fewer stable favorable beliefs being more likely to have an episodic dental visiting pattern (APPENDIX Table
The mean of the summed scores from the six belief statements was 10.9 (SD 2.6) at age 15 yrs, 11.1 (SD 2.6) at age 18 yrs, and 11.1 (SD 2.4) at age 26 yrs. There were no statistically significant differences in population mean-level stability across those ages; however, the rank-order stability was relatively low, at 0.641 (95% CI 0.594, 0.684), indicating individual instability across time.
Associations with Oral Health Outcomes
After adjustment for potential confounders by regression analysis, those with stable favorable beliefs had a significantly lower prevalence of poor self-rated oral health, fewer sites with bleeding on probing, fewer teeth extracted due to caries, lower plaque scores, and greater mean DFS and FS than those Study members with fewer stable favorable beliefs ().
Table 4 Estimates of Stable Favorable Dental Health Beliefs by Oral Health Outcome Measures at Age 26 yrs after Adjustment for Sex and Childhood SES*, as Well as Fluoride Exposure for Caries-related Outcomes and Smoking for Periodontal-disease-related Outcomes (more ...)
By age 26 yrs, 179 Study members (24.2%) had spent all their lives in a fluoridated area, 422 (60.0%) had lived some of their lives in one, and 80 (10.8%) had not. More of those from fluoridated areas considered water fluoridation to be important than those who had never lived in fluoridated areas (76.8% and 63.8%, respectively; P < 0.05). No other statistically significant difference in beliefs existed between those groups.