Aj Spencer

Effects of Fluoridated Drinking Water on Dental Caries in Australian Adults

Systematic reviews produce conflicting conclusions regarding dental caries-preventive effects of water fluoridation in adults. The authors investigated the relationship using data from the nationally representative 2004−2006 Australian National Survey of Adult Oral Health. Effects were compared between the pre-fluoridation cohort born before 1960 (n = 2,270) and the cohort born between 1960 and 1990 (n = 1,509), when widespread implementation of fluoridation increased population coverage from < 1% to 67%. Residential history questionnaires determined the percentage of each person’s lifetime exposed to fluoridated water. Examiners recorded decayed, missing, and filled teeth (DMF-Teeth) and decayed and filled tooth surfaces (DF-Surfaces). Socio-demographic and preventive dental behaviors were included in multivariable least-squares regression models adjusted for potential confounding. In fully adjusted models, > 75% of lifetime exposure to fluoridation relative to < 25% of lifetime exposure was associated with 11% and 10% fewer DMF-Teeth in the pre-1960 (p < .0001) and 1960–1990 cohorts (p = .018), respectively. Corresponding reductions in DF-Surfaces were 30% (p < .001) and 21% (p < .001). Findings for intermediate fluoridation exposure suggested a dose-response relationship. Results were consistent in sensitivity analyses accounting for missing data. In this nationally representative sample of Australian adults, caries-preventive effects of water fluoridation were at least as great in adults born before widespread implementation of fluoridation as after widespread implementation of fluoridation.

Risk-benefit balance in the use of fluoride among young children.

This study aimed to evaluate the risk-benefit balance of several fluoride exposures. Fluoride exposure history of randomly selected children was collected for calculation of exposure to fluoridated water, toothpaste, and other fluoride sources. We evaluated the risk-benefit balance of fluoride exposure by comparing dental fluorosis on maxillary central incisors, recorded at the time of the study with the use of the Thylstrup and Fejerskov Index, and deciduous caries experience, recorded at age six years, of the same group of South Australian children who were from 8 to 13 years old in 2002–03. Population Attributable Risk for fluorosis and Population Prevented Fraction for caries were estimated. Fluorosis prevalence was found to be 11.3%; caries prevalence, 32.3%; mean dmfs, 1.57 (SD 3.3). Exposure to fluoridated water was positively associated with fluorosis, but was negatively associated with caries. Using 1000-ppm-F toothpaste (compared with 400- to 550-ppm-F toothpaste) and eating/licking toothpaste were associated with higher risk of fluorosis without additional benefit in caries protection. Evaluation of the risk-benefit balance of fluoride exposure provides evidence to assist in the formulation of appropriate guidelines for fluoride use.

Does Psychological Stress Mediate Social Deprivation in Tooth Loss

It is unclear which theoretical dimension of psychological stress affects health status. We hypothesized that both distress and coping mediate the relationship between socio-economic position and tooth loss. Cross-sectional data from 2915 middle-aged adults evaluated retention of < 20 teeth, behaviors, psychological stress, and sociodemographic characteristics. Principal components analysis of the Perceived Stress Scale (PSS) extracted ’distress’ (a = 0.85) and ’coping’ (a =0.83) factors, consistent with theory. Hierarchical entry of explanatory variables into age- and sex-adjusted logistic regression models estimated odds ratios (OR) and 95% confidence intervals [95% CI] for retention of < 20 teeth. Analysis of the separate contributions of distress and coping revealed a significant main effect of coping (OR = 0.7 [95% CI = 0.7–0.8]), but no effect for distress (OR = 1.0 [95% CI = 0.9–1.1]) or for the interaction of coping and distress. Behavior and psychological stress only modestly attenuated socio-economic inequality in retention of < 20 teeth, providing evidence to support a mediating role of coping.

Quality of Life and Disability Weights Associated with Periodontal Disease

Burden-of-oral-disease studies have been hampered by lack of data on disability weights. It is likely that disability weights will vary between conditions such as gingivitis and periodontal pockets. The aims of this study were to assess health-related quality of life and disability weights for periodontal conditions. A random sample of 45- to 54-year-olds was surveyed during 2004-05 (n = 879, response rate = 43.8%), with oral examinations on n = 709 persons (completion rate = 80.7%). Oral disease symptoms were recorded by the EuroQol, from which disability weights were calculated. Reported pain/discomfort ranged from 6.1% of persons (gingivitis) to 25.8% of persons (6+ mm pockets). Lower disability weights were associated with gingivitis (0.001) and 6+ mm gingival recession (0.004), with higher weights for 6+ mm loss of attachment (0.012) and 6+ mm pocket depth (0.018). Variation in symptom experience indicated the need for investigators to identify periodontal conditions and apply appropriate disability weights in burden-of-disease studies.

Quarter of a century of change : caries experience in Australian children, 1977-2002

BACKGROUND The establishment of the evaluation programme of the Australian School Dental Scheme has led to continuous surveillance of child oral health extending from 1977 to the present day. The aims of this study were to examine the state of child oral health in Australia in 2002 and to explore longer term trends across the quarter of a century of recorded surveillance activity. METHODS Caries data were obtained for children who were enrolled in the School Dental Services of each state and territory for the years 1977-2002. Data collection derived from routine examinations within the School Dental Service with oral examinations carried out by dentists and dental therapists. RESULTS There were considerable declines in caries experience between 1977 and the mid to late 1990s, with mean decayed, missing and filled deciduous teeth (dmft) for 6-year-old children decreasing from over 3 in 1977 to approximately 1.6 in 1996, and permanent 12-year-old decayed, missing and filled teeth (DMFT) decreasing from 4.8 in 1977 to 0.89 in 1998. However, since the mid to late 1990s, deciduous 6-year-old dmft has increased by 24 per cent and 12-year-old DMFT has increased by almost 15 per cent. Reductions in caries experience of those children with the most disease have also ceased, and between 1999 and 2002 an increase in the Significant Caries Index occurred. CONCLUSIONS Improvements in the oral health of Australian children halted during the mid 1990s, after which caries experience has increased. It is important that we understand the changes taking place and their causes, so that action can be taken to halt any further possible declines in child oral health.

Trend of Income-related Inequality of Child Oral Health in Australia

It is important that we monitor socio-economic inequality in health. Inequality in child oral health has been expected to widen because of widening socio-economic inequality. This study aimed to evaluate trends in income-related inequality in caries experience of Australian children. Cross-sectional studies in 1992/93 and 2002/03 collected data on deciduous caries experience of 5- to 10-year-olds and permanent caries experience of 6- to 12-year-olds. Household composition and income was used to calculate quartiles of equivalized income. Slope Index of Inequality (SII), Concentration Index (CI), and regression-based rate ratios were used to quantify income-related inequality and to evaluate trends. Income-related inequality in caries experience was evident regardless of time and dentition. The three indicators of inequality indicate a significant increase in income-related inequality in child deciduous caries experience during the decade. The income inequality in permanent caries experience did not change significantly. Income inequalities increased in deciduous teeth, but not in permanent teeth, among Australian children.

Changes in caries experience among Australian public dental patients between 1995/96 and 2001/02

Objective: Health Card holders are a financially disadvantaged group and are the target population eligible for public‐funded dental care. The aims of this study were to describe the oral health status of public‐funded dental patients by age, sex, type of care and geographic location, and to compare trends over time.

Effects of Water Fluoride Exposure at Crown Completion and Maturation on Caries of Permanent First Molars

Pre-eruptive fluoride exposure has been shown to be important for caries prevention. This paper aimed to determine the relative effects of water fluoride exposure during crown completion (CC) and maturation on caries experience in first permanent molars. Parental questionnaires covering residential history were linked to oral examinations of 19,885 6- to 15-year-old Australian children conducted in 1992 by the School Dental Services of South Australia and Queensland. The percentage of lifetime exposed to optimally fluoridated water at CC, maturation (MAT) and post-eruption (POST) was calculated. Combined exposure variables describing different levels of CC, maturation and post-eruption were created using a threshold exposure of 50%. Compared to the reference of CC <50%/MAT <50%/POST <50%, the categories CC ≧50%/MAT <50%/POST ≧50% [rate ratio (RR) 0.52], CC ≧50%/MAT ≧50%/POST <50% (RR 0.61) and CC ≧50%/MAT ≧50%/POST ≧50% (RR 0.67) had the strongest caries-preventive effect, followed by CC ≧50%/MAT <50%/POST <50% (RR = 0.79) and CC <50%/MAT ≧50%/POST ≧50% (RR = 0.81) in negative binomial regression models (p < 0.05). The categories CC <50%/MAT ≧50%/POST <50% (RR = 0.85) and CC <50%/MAT <50%/POST ≧50% (RR = 0.84) had weaker, non-significant caries-preventive effects. In conclusion a high exposure at CC was important for caries prevention irrespective of the effect of exposure at maturation and post-eruption. The strongest caries-preventive effect was produced by a high exposure at CC supplemented by a high exposure at maturation and/or post-eruption, but the latter two phases could not produce a significant caries-preventive effect on their own. Since most of the caries occurred on pit and fissure surfaces, the findings relate to this class of lesion.

Job satisfaction of the oral health labour force in Australia

BACKGROUND Job satisfaction among registered clinical dentists in Australia was measured to identify issues influencing recruitment and retention. METHODS A questionnaire was mailed to a random sample of 2202 dentists, stratified by state and gender, selected from the 2005 Australian Dental Association directory. RESULTS A total of 61.9% of dentists responded. Analyses showed significant differences in levels of satisfaction for various dimensions of job satisfaction by gender, age group, practice type and geographic area. Differences in satisfaction between male and female dentists related to the relationships with colleagues and administrative responsibilities dimensions. Dentists of different age groups differed on eight dimensions: relationships with colleagues, patients, staff; personal time; intrinsic satisfaction; community; administrative responsibilities and resources. Differences among private and public dentists related to autonomy, relationships with patients, staff, community, compensation and resources dimensions. Dentists working in different geographic areas differed on relationships with staff and community dimensions. CONCLUSIONS Differences existed between private and public dentists, metropolitan and non-metropolitan dentists, male and female dentists and dentists of different ages. Such differences should be addressed in order to improve recruitment and retention rates of dentists. Workplaces that offer job autonomy, competitive pay, flexible working hours and minimal administrative burden may improve dentist job satisfaction.

Greater Inequalities in Dental Treatment than in Disease Experience

This study aimed to (1) describe social gradients in dental caries in a population-level survey and (2) examine whether inequalities are greater in disease experience or in its treatment. Using data from Australia’s National Survey of Adult Oral Health 2004-2006, we examined absolute and relative income inequalities for DMFT and its separate components (DT, MT, FT) using adjusted proportions, means, and health disparity indices [Slope Index of Inequality (SII) and Relative Index of Inequality (RII)]. Approximately 90% of Australian adults had experienced caries, with prevalence ranging from 89.7% in the highest to 96.6% in the lowest income group. Social gradients in caries were evident across all components of DMFT, but particularly notable in Missing (SII = −15.5, RII = −0.3) and untreated Decay (SII = −23.7, RII = −0.9). Analysis of age- and gender-adjusted data indicated less variation in levels of disease experienced (DMFT) than in the health outcomes of its management (missing teeth). The findings indicate that social gradients for dental caries have a greater effect on how the disease was treated than on lifetime disease experience.