Oral health status and perception of oral health of young Australian adults


Address for correspondence:

Dr Loc Do

Australian Research Centre for Population Oral Health

School of Dentistry

The University of Adelaide

Adelaide SA 5005

Email: loc.do@adelaide.edu.au


Young adults in Australia have enjoyed significantly better conditions of life than older generations.[1] Oral health status in young Australians has significantly improved in recent decades. However, certain groups of the young population still carry the majority of the dental disease burden of the population.[1]

Oral diseases and disorders can have a negative impact on the life of individuals. For example, dental caries can lead to toothache, which can be distressful and worrying for the affected individuals.

Oral disease and disorders are measured in population studies using clinical measures recorded by dental clinicians during oral examinations such as the decayed, missing and filled index for caries. These indices indicate the presence and severity of an oral condition. However, perceptions of oral health must necessarily be reported by the people who experience those conditions. Identifying a link between oral health status and perception of oral health reported by individuals is necessary.

This study aimed to report on the association between oral health status measured as dental caries experience and perception of oral health reported by young adults.


Data were derived from the Life Course Approach to Oral Health Inequalities Study and the Caries Initiation Study, two follow-up substudies of a cohort of South Australians who were recruited into the Child Fluoride Study (CFS) in 1991–1992 when they were aged 4–15 years. The CFS included a random sample of 9996 children enrolled in the South Australian School Dental Service. In 2005–2006, the participants were traced using the electoral roll in South Australia. Letters sent to parents' addresses retrieved updated contact information for an additional 1202 individuals, leading to a total of 7663 subjects traced (76.7% of CFS participants). A questionnaire and an invitation letter were sent to the traced participants. Study participants who completed the questionnaire were invited to undertake an oral epidemiological examination. The examination process was undertaken during the 2009–2011 period.

Study participants were asked to rate their oral health status using a Likert-type scale. Five categories were used: Excellent, Very Good, Good, Fair and Poor. Socio-economic status (SES) was collected as household income, educational attainment and concession card holder status. Oral health behaviours and dental visiting patterns were collected to group the study participants into different categories of behaviour and visiting.

Oral epidemiological examinations were conducted by specially trained and calibrated examination teams comprising of a dentist examiner and a recorder. Dental caries experience was measured as DMFS (a summary measure of decayed (D), missing (M), filled (F) tooth surfaces) and its components. Examinations were conducted under standardized clinical conditions in South Australia Dental Services' clinics.

Data analysis was performed in SAS for Windows version 9.3 and SUDAAN for Windows version 11.0. Data were analysed progressively from bivariate analysis to multivariate model. Number of untreated decay was used as an indicator of clinical oral health status in the final multivariate model. Ethical clearance was given by the University of Adelaide Human Research Ethics Committee.


A total of 1221 young adults completed the oral epidemiological examination (Table 1). The majority of the study participants were in the range of 20–29 years of age. There were more males than females in the sample. A third reported household income over A$78 000 while over 11% were in the lowest income category. There was an even distribution of the sample by education. Some 57% reportedly brushed their teeth less than twice a day. A quarter of the sample visited for relief of pain and some 8% visited for other problems.

Table 1. Study sample characteristics, oral health behaviours and dental visiting patterns
 N (total 1221)%
Age at examination
20–24 years45237.0
25–29 years53944.1
30–35 years23018.8
Household income
<36 400 A$13511.1
36 400–<52 000 A$15812.9
52 200–<78 000 A$18915.5
78 000+ A$41333.8
School only37132.0
Vocational training37732.5
Tertiary or higher41135.5
Brushing frequency
<2 times/day69757.1
2+ times/day52442.9
Usual reason for dental visit
Relief of pain26924.3
Other problems958.6
Concession card holder

Caries experience measured by DMFS score was strongly associated with age (Table 2). There was an income-related gradient in oral health status in the study sample. Those who were in the lower income group had a higher level of caries experience than those in higher groups. However, the difference was not statistically significant. The group with tertiary education had the lowest level of the disease compared with the other two groups. Those who reportedly brushed their teeth infrequently had higher, albeit not statistically, mean DMFS scores than those who brushed at least twice a day. Those who visited for relief of pain had more than double mean DMFS scores than those who visited for a check-up. Concession card holders had significantly higher mean DMFS scores compared to their non-card holder counterparts.

Table 2. Oral health status by study sample characteristics
 Mean DMFS95% CI
  1. 95% CI: 95% Confidence Intervals. Statistically significant if CIs do not overlap.

Age at examination
20–24 years3.813.31–4.31
25–29 years5.694.94–6.45
30–35 years7.456.17–8.72
Household income
<36 400 A$6.624.99–8.26
36 400–<52 000 A$5.914.33–7.49
52 200–<78 000 A$5.194.27–6.11
78 000+ A$4.523.92–5.12
School only5.294.52–6.06
Vocational training5.775.01–6.53
Tertiary or higher4.423.82–5.03
Brushing frequency
<2 times/day5.705.08–6.32
2+ times/day4.834.16–5.50
Usual reason for dental visit
Relief of pain8.327.15–9.48
Other problems5.644.04–7.24
Concession card holder

Some 16.2% of the study participants rated their oral health as Fair or Poor (Table 3). There was no significant association between age at examination and perception of oral health. However, there were significant gradients in perception of Fair or Poor oral health by SES. Those of lower socio-economic groups were significantly more likely to negatively perceive their oral health than those of higher SES. There were also significant associations between perception of oral health and toothbrushing frequency and usual reason for dental visit.

Table 3. Perception of oral health status by study sample characteristics
 Exc/V good/GoodFair/Poor
%95% CI%95% CI
  1. a

    Chi-square test: p < 0.05.

Age at examination
20–24 years83.279.7–86.616.813.4–20.3
25–29 years84.681.5–87.715.412.3–18.5
30–35 years82.277.2–87.117.812.9–22.8
Household incomea
<36 400 A$73.566.1–81.026.519.0–33.9
36 400–<52 000 A$81.975.9–87.918.112.1–24.1
52 200–<78 000 A$84.178.9–89.315.910.7–21.1
78 000+ A$87.884.6–90.912.29.1–15.4
School only77.573.2–81.722.518.3–26.8
Vocational training82.078.1–85.818.014.2–21.9
Tertiary or higher91.188.3––11.7
Brushing frequencya
<2 times/day79.176.1–82.120.917.9–23.9
2+ times/day90.087.4–92.510.07.5–12.6
Usual reason for dental visita
Relief of pain69.163.6–74.630.925.4–36.4
Other problems71.962.9–80.928.119.1–37.1
Concession card holdera

There were associations between caries experience measured by adjusted mean decayed, missing or filled tooth surfaces and self-rated oral health (Fig. 1). Those who reported their oral health as Fair or Poor had a significantly higher number of tooth surfaces with untreated decay and missing tooth surfaces.

Figure 1.

Adjusted mean decayed, missing or filled tooth surfaces by self-rated oral health. Caries experience adjusted for age, gender, socio-economic status and dental visiting patterns.

A number of factors were found associated with perception of Fair/Poor oral health in a multivariate model (Table 4). Those who had lower education attainment had 1.66 and 1.44 higher times the rate of perceiving oral health as Fair or Poor compared to the group with tertiary education. Those who brushed their teeth less than twice a day were 1.59 times more likely to perceive oral health as Fair or Poor compared with the other group. Usual reason for dental visit had a strong association with perception of oral health. An increase by one tooth surface with untreated decay was associated with 1.05 times higher the likelihood of perceiving oral health as Fair or Poor, controlling for other factors.

Table 4. Factors associated with perception of Fair/Poor oral health
 RR95% CI
  1. Multivariate model for perception of Fair/Poor oral health, adjusted for all variables and age and gender.

  2. RR: Adjusted Rate Ratios.

  3. 95% CI: 95% Confidence Intervals. Statistically significant against the reference if CIs do not include unity.

Household income
<36 400 A$1.320.91–1.92
36 400–<52 000 A$1.160.81–1.66
52 200–<78 000 A$1.050.75–1.48
78 000+ A$ref 
School only1.631.16–2.29
Vocational training1.431.02–2.02
Tertiary or higherref 
Brushing frequency
<2 times/day1.541.16–2.04
2+ times/dayref 
Usual reason for dental visit
Relief of pain2.902.17–3.89
Other problems2.491.70–3.64
Concession card holder
Mean decayed surfaces (continuous variable)


The current analysis indicates that young Australian adults still carried a certain amount of dental caries experience, although the observed level of the disease was significantly lower than that of older generations at the same age. The other notable finding was the significant variation of the disease level by socio-economic groups, oral health behaviours and dental visiting patterns.

This analysis used cross-sectional data. Therefore, it was not possible to imply any causal relationship between oral health status and factors such as SES and dental visiting patterns. Another longitudinal study among young adults reported a relationship between socio-economic factors with patterns of dental visiting in the preceding two years.[2] It is necessary to address not only the dental visiting behaviours of young adults but also problems with access and affordability that people in this age group encounter.

This study reported an association between socio-economic factors and with both clinical measure of oral health and subjective perception of oral health. The association with the perception of oral health persisted even after controlling for the clinical measure of oral health. Other socio-economic factors may also be determinants of the subjective perception of oral health in this population.

Dental caries experience appeared to strongly impact on people's perception of their oral health. The other common oral disease, periodontal disease, is not common in this age group.[3] Preventing dental caries remains a priority for young Australian adults.


This report was prepared by Loc Do. The Life Course and Caries Initiation studies are supported by National Health and Medical Research Council (NHMRC) project grants.