Main

In most of the westernised countries that undertake oral health surveys, oral health has generally improved. Even those countries which have had very high levels of disease have shown reductions in dental disease experience, often most apparent in the younger age groups.1,2 On the whole though, people have more teeth than they had in the past and more of them are disease-free.3,4,5

The national surveys of Adult Dental Health have given a 10-yearly summary of the clinical condition of adults in the United Kingdom on three previous occasions. The fourth report in the series was published in March of 2000.6 For the 1998 survey 4,984 addresses were identified at which all adults over 16 in residence were asked to take part in the survey; 21% of households refused and no contact was made at 5% of them. In total, 6,204 adults were interviewed following which those with some teeth were asked to undergo a dental examination; 3,817 (72%) of those eligible agreed. A weighting system based on some of the interview responses of those who consented to be dentally examined and those who were interviewed but not dentally examined was used to reduce bias from non-response.6 The survey was carried out under the auspices of the Office of National Statistics together with the Universities of Birmingham, Dundee, Newcastle-upon-Tyne and Wales.

The clinical examinations collected information about the state of the teeth and restorations as well as information on spacing and how this is restored. It was felt important to include, for the first time, an assessment of visual caries (dentine involvement but not cavitated lesions) as well as lesions that had proceeded to cavitation. In younger populations especially, the former is an important marker of disease typically requiring restorative intervention. Also for the first time, tooth wear was measured. This article looks at the condition of teeth in the United Kingdom.

Has the overall condition of teeth changed since 1978?

Figure 1 shows that the number of teeth among dentate adults without signs of disease or treatment has increased since 1978 from 13 sound and untreated teeth on average to 15.7 in 1998. Over the same period the number of filled teeth has stayed much the same at around 8.1 teeth between 1978 and 1998 but the number of teeth which are either decayed or missing has dropped, in the case of untreated decay by almost a half, over the last 20 years.

Figure 1
figure 1

The mean number of teeth in each condition, 1978–98: (a) missing, (b) decayed or unsound, (c) restored, otherwise sound, (d) sound and untreated (1998 data is based on 1988 criteria)

Full size image

However, this conceals an important age trend. Filled teeth have declined markedly among young adults but increased among older adults (Table 1). Dentate adults aged 16–24 had an average of 2.9 filled teeth in 1998 compared with 8.0 in 1978. Among dentate adults aged over 45 the average number of filled teeth in 1998 had risen by at least 50% of the average in 1978. Is this a sign of unnecessary dental treatment in the past among the older age groups? We think not; the average number of sound and untreated teeth among older dentate adults has not decreased as restorative treatment has increased. What has decreased among this group is the number of decayed and the number of missing teeth. This suggests that the increased experience of restorative dental treatment among the elderly is by and large reflected by a lessening experience of tooth loss. However, with increasing age, more and more teeth become involved in the restorative cycle, particularly in middle age. For adults aged over 55 years, a significant disability may be imposed by the extraction of diseased teeth.

Table 1 Table 1
Full size table

What is the type and extent of dental caries among dentate adults in the United Kingdom?

In previous national dental surveys the assessment of dental decay included a measurement of cavitated lesions and severely broken down teeth only. In the 1998 survey, in addition to these more advanced signs of decay an assessment of visual decay (the stage of the caries process where there is demineralisation but not cavitation) was included to give a more realistic assessment of the current prevalence of dental decay.

Overall 24% of dentate adults had visual primary caries, 22% primary cavitated caries and 8% had recurrent cavitated caries (Fig. 2).

Figure 2
figure 2

Proportion of adults with visual decay, primary cavitated decay or recurrent decay by age

Full size image

Whilst dental intervention, sealants, dietary messages, plaque control, and minimal restorations, would seem to be appropriate, given what happens to the dental health of the cohorts as they age, it need not necessarily be given by dentists. Indeed, in the light of the likely work required, it may not need to be. The advent of professions complementary to dentistry (PCDs) within dental practice may in future lead to a more cost-effective skill mix within primary care dentistry to enable such a strategy to be adopted, notwithstanding the evolving nature of clinical conditions that will need to be managed over the next few decades.

Which teeth have been affected by caries?

Figure 3 shows the distribution of dental caries (cavitated lesions affecting dentine) and its treatment around the mouth of dentate adults. Overall, molars were the teeth most affected by disease, with 85% of them either missing, decayed, unsound or restored. This was particularly marked for the youngest age group, 16–24 year-olds, where the first and second molar teeth bear the brunt of the disease experience. Apart from a small proportion of restorations in teeth that are more anterior in the arch, and the loss of first premolars for orthodontic purposes, about one third of first permanent molars are restored and just over one tenth have untreated decay.

Figure 3
figure 3

Distribution of tooth conditions around the mouth

Full size image

The distribution of different conditions around the mouth shows that the majority of disease experienced in the youngest age group and for successive cohorts is concentrated in first and second molar teeth.6 The application of sealants to these teeth could dramatically alter the overall disease experience both now and in the future. As it is, a significant number of teeth will require maintenance and re-maintenance for years to come. Yet fissure sealants were only found in 23% of this age group.

The survey reports that there is almost 50% less decay in those who attend for regular dental check-ups than those who only go to a dentist when they have trouble with their teeth.6 However, it is disturbing that over one third of regular attenders have some form of decay, albeit largely primary, visual decay. Of concern is the relatively high proportion of 16–24 year-olds who have decay; half have some primary decay, a third of which is visual, a fifth cavitated and 6% have unrestorable teeth. Whilst these young people have, until recently, had access to dental to care in either general dental practice or the community dental service, only 49% of this age group reported visiting a dentist regularly. Forty eight per cent of the 16–24-year-olds, reported less frequent attendance than five years ago.6

Although it is up to the individual as to whether they visit a dentist, the dental service could be seen to be failing in one of its objectives, of encouraging routine dental care, when so many of its regular patients do not maintain this attendance pattern. A significant proportion of the population seemingly does not receive regular care at all. What role should the dental profession play in this?

Root caries

One of the concerns in the dental profession is the propensity for an increase in the prevalence and incidence of root caries given the changing age profile of the population and the increasing retention of natural teeth into old age. Linked with this are the age-associated changes in the periodontal tissues such that vulnerable root surfaces are exposed to the oral environment and thus, potentially, the caries process.

Two thirds of all adults had at least one tooth with a root surface which was vulnerable to decay (either exposed, worn, decayed or filled), and on average 6.4 teeth were in this condition. However, the pattern was not uniform with only 1.2 vulnerable teeth in younger adults compared with 10.6 in adults aged 65 years and over. This represents well over half of the teeth present at this age. Amongst the 29% of older adults (65+) who had root caries, on average 2.3 teeth were affected. By contrast, 54% of older adults had some caries around the crown of the tooth (often recurrent around existing restorations), and the number of teeth affected was very similar to that for roots (2.2). The prevalence of caries on root surfaces is approaching that for coronal caries in older people. The majority of decay affecting roots was active decay (9% of vulnerable surfaces), as opposed to arrested (2%), recurrent (1%) or unrestorable (3%) decay.

On the basis of these data, root caries is not likely to be a huge public health problem in younger age groups. However, in older age groups a significant proportion of the caries burden falls on the exposed roots. Most of the root caries found in this survey related to new lesions. This is in contrast to the rather higher proportion (around a third) of decay in the crowns of the teeth which was recurrent around existing restorations. Some of the interventions required to treat the root decay in older adults will certainly be operative, but much of it may be able to be dealt with more simply. The scope for preventive care is considerable. A concerted preventive strategy for the younger cohorts of adults who are still disease free, and for the older adults at greatest risk of root caries may make an impact. This may be another area where the PCDs have a role to play.

Less disease – but are they wearing away?

To an extent, tooth wear is part of the normal ageing process of the dentition. When it is excessive, such that the longevity of the tooth is threatened, it becomes a clinical concern. Alongside this of course are considerations of the patient-driven concerns about poor aesthetics, sensitivity and with increasingly severe wear, function.

  • The clinical examination was confined to the palatal, labial and incisal surfaces of the six upper anterior teeth, and the worst affected surface of the lower anterior teeth. These surfaces were selected on the basis of evidence from previous surveys7,8 as being the ones most likely to be affected if wear was present elsewhere in the mouth.

The data were categorized as follows for the purpose of presentation:

  • Any tooth wear, excluding that confined only to enamel

  • Moderate wear – involving more extensive exposure of dentine

  • Severe wear – complete enamel loss with exposure of pulp or secondary dentine.

Two thirds of all adults had some wear into dentine on anterior teeth. For 11% of adults the wear was moderate (extensive involvement of dentine) and 1% had severe wear. As with most other dental conditions, the prevalence of tooth wear did increase with age: a third of the youngest adults had some evidence of tooth wear on anterior teeth compared with 89% of those aged 65 years and over. There were no significant differences in the prevalence of any tooth wear recorded between people from different social classes or different attendance patterns, but more males than females had some tooth wear, especially severe tooth wear. Scottish adults were least likely to have any tooth wear compared with the other countries of the UK. There were little inter-regional differences for tooth wear but those adults living in the Midlands had less moderate tooth wear (7%) than did adults living in the north or the south (12%) of England. Geographical differences should be interpreted with some caution though because of the possibility of inter-examiner variability.

Contrasting these data with that from the oldest age group in the 1993 UK children's dental health survey,9 (the young people who would therefore be included in the 16–24-year-old group in the 1998 adult survey), there was a similar amount of tooth wear in both groups; in the children's dental health survey, 2% of the older children were recorded as having wear into dentine/pulp, comparable to the moderate/severe categories in this study – in 1998, 1% of 16–24-year-olds had moderate tooth wear (Table 2).

Table 2 Table 2
Full size table

It is encouraging to note that there has apparently been virtually no increase in the amount of wear in young peoples' teeth over the past few years; the children's dental health survey9 showed quite a worrisome picture of a high experience of erosion overall in the permanent teeth, although the proportion of young people with dentine involvement was only 2%, very similar to the data for 16–24-year-olds from the 1998 adult survey.

What are the implications for those providing dental services to adults in the UK?

The overall trends reported in the adult dental health survey of 1998 give reason for some optimism. However, closer inspection of the data reveals considerable shortcomings in the way in which oral and dental disease are managed in adults in the UK. Young adults have little evidence of dental intervention which is good, providing that is appropriate; what is disquieting is the way in which dental caries is mismanaged in the younger cohorts where 50% have untreated decay, visual or cavitated.

The inclusion of an assessment of 'visual' caries for the first time obviously raises issues about the usefulness or otherwise of doing so, given that surveys have a limited use for needs assessment and service utilisation and, inclusion of this assessment also increases the costs of surveys. In a number of populations 'visual' caries is going to be more prevalent, especially in young people,10 but many of these lesions may remain static or regress; we do not know since this depends on conducting well-designed longitudinal studies. In terms of targeting populations for preventive measures, the balance between visual and cavitated lesions becomes important; if they are present in higher numbers than cavitated lesions, a sealant/preventive resin restoration programme is to be advocated. If, however, they are present in equal proportions then the implication is that caries progression is relatively rapid and a fluoride-based preventive programme would be more appropriate.

Fluorides and sealant based preventive programmes may make an impact in certain areas, but the role of hygiene in preventing dental caries should not be ignored either. This applies particularly to caries on free smooth surfaces, specifically perhaps to the emerging issue of root surface caries in older adults. Despite a multi-million pound oral hygiene industry and regular dental attendance amongst a majority of the adult population, evidence from elsewhere in this survey6 suggests that there is still a widespread problem with hygiene. The reported frequency of toothbrushing had little effect on periodontal disease and, even amongst the majority of people who purported to be regular tooth-brushers, the prevalence of visible plaque deposits was still very high. The profession still has a key role to play here too.

The pattern of disease and the emphasis of treatment does seem to be changing. In younger adults there are fewer restorations than hitherto and simple, minimally damaging techniques may be appropriate to manage disease. In older adults there are more restorations, often large, complex and requiring time and advanced professional skills to maintain. The evidence that change is needed in the way treatment is delivered to reflect this is compelling. Innovations, such as the development of a greater role for PCDs, may offer some of the solutions for managing this changed environment.