May 1, 2004
by Oral Health
Dr. J.M. Symington, BDS, MSc, PhD, FDSRCS and Mr. O.R. Perry, MSc
THE GROWING NUMBER OF OLDER PATIENTS
In Part 1 of this series on Canada’s aging population, we observed how, if trends continue, the number of dental visits will grow at less than the population rate and the type of dental services provided will change. By 2021, there will be eight million Canadians age 55+ years without dental insurance–representing about 1 in 4 Canadians. More than one third of these retirees will have root caries and will need associated restorative and periodontal services.
CARIES INCREMENT INCREASES WITH AGE
As there are no published studies on caries increment by age group among older Canadians, insight on the relationship between aging and caries must be gained from other regions. A relevant study of community-dwellers in Sweden observed caries increment at both the crown and root surface over five years for individuals aged 60, 70 and 80 years.1 This study reported a significant increase in the rate of caries onset and progression with advancing age both on the crown and root surface.
Those who were 80 years of age experienced a caries attack rate (a normalized measure of new lesions per surfaces at risk) three and four times than those 60 years of age, on the coronal and root surfaces respectively.
If this Swedish caries increment model applies to Canada’s aging population, there will be an unprecedented level of caries for Canadian dentistry over the next 20 years.
The Distribution of Caries in Older Adults in Canada: Caries is clustered in all age groups, such that a few are sick with this disease while many are untouched. For older adults (age 50+) living in four Ontario communities, Hawkins’ group reported that 43 percent had no caries over three years while 13.6 percent experienced 42.6 percent of this disease2 (Fig. 2).
Dental visits and in particular, dental spending in Canada over the medium term, thereby, will hinge largely on the behaviour of the at-risk older adult–the 20 percent of those aged 55+ who are regularly in need of dental restoration. This critical segment for Canadian dentistry is projected to number 2.4 million Canadians by 2021, up 68 percent from 2001.
OLDER PATIENTS–THE INFLUENCE OF OTHER CHRONIC DISEASES
There is growing awareness of how periodontal health in older patients might influence the risk of cardiovascular disease and cerebral vascular accident (stroke).
Equally important in an aging society is the effect of other chronic diseases on oral health and the need for dental care, as well as on the ability to purchase dental care and to get to the dental office.
Based on recent trends in morbidity in the Canadian population shown in Fig. 3, the numbers experiencing one or more chronic systemic diseases will increase dramatically over the medium term. The number of Canadians age 55+ with hypertension, for example, will grow from 1.7 million today to almost three million in 2021.
Coincidentally, a growing level of multiple medication use or “poly-pharmacy” can also be expected. During the mid 1990s, Statistics Canada reported that 29 percent of Canadians between 65 and 75 years were taking three or more medications regularly.
Amongst Canadians aged 75 years and older in the late 1990s, the average number of medications taken ranged from 7.1 in British Columbia to 5.2 in Atlantic Canada.3
Multiple medication use is particularly common amongst Canadians with hypertension and arthritis, the most common diseases in older Canadians. More than half of those Canadians with hypertension and 4 out of 10 with arthritis are taking three or more drugs.
MEDICATION PROFILES AMONGST OLDER ADULTS AT-RISK OF CARIES
The authors have examined the medications taken by an at-risk caries population of older adults in three North American cities. In this study, the average age of the participants was 59 years, and the incidence rate of new lesions was 3.39 over 12 months. This level of caries increment placed this study population in the 20 percent of the adult population, which experiences most of the caries shown in Fig. 2.
In this at-risk study population, three medications were most common–anti-hypertensives, anti-depressants and analgesics (Fig. 5).
In terms of multiple medication use, about 1 in 4 of these patients took six medications regularly. Over 90 percent of study participants took fewer than seven medications (Fig. 6).
MULTIPLE MEDICATION USE LEADS TO DRY MOUTH WHICH LEADS TO CARIES
These connections have been reported in the research literature although there has been no single study observing the growth of caries increment in a population with the growing use of medications. Nederfors’ group found a direct association between dry mouth and the number of medications in Swedish adults4 (Fig. 7).
Papas’ group reported that community living adults in Boston who had xerostomia had significantly higher levels of both root and coronal decay than those of comparable age and normal salivary flow.5 Figure 8 shows these differences at the root surface.
By far the fastest growing age groups in Canada over the medium term will be the retirees (ages 65-75) and the old (age 75+). Caries affects about 1 in 5 older Canadians, and from Swedish research, the caries increment significantly increases with age. Part of the aging process is chronic disease and multiple medication use, and concomitantly, growing prevalence of dry mouth.
A study of older Canadians and Americans at high risk of caries and experiencing a high level of this chronic disease, found these patients to be medicated primarily for hypertension, chronic pain and depression.
The future demographics of Canada point, therefore, to a dental patient with more complex dental needs and medical histories, and a higher burden of caries.
Dr. J.M. Symington, BDS, MSc, PhD FDSRCS (England).
Mr. O.R. Perry, MSc.
1.S. Fure, “Five-year incidence of caries, salivary and microbial conditions in 60-, 70- and 80-year-old Swedish individuals”, Caries Research, v.32, 1998, pp. 166 – 174.
2.R. Hawkins et al, “Three-year coronal caries incidence in older Canadian adults”, Caries Research, v.31, 1997, pp. 405 – 410.
3.D. Hogan et al, “Regional variation in the use of medications by older Canadians–a persistent and incompletely understood phenomena”, Pharmacoepidemiology and Drug Safety, v.12, 2003, pp. 575-582.
4.T. Nederfors et al, “Prevalence of perceived symptoms of dry mouth in an adult Swedish population –relation to age, sex and pharmacotherapy”, Community Dentistry and Oral Epidemiology, v.25, 1997, pp. 211 – 216.
5.A. Papas et al, “Caries prevalence in xerostomic individuals”, Journal of the Canadian Dental Association, v.59, 1993, pp. 171 – 179.