The proportion of older adults in populations across the world is increasing, and this ageing population is going to present dentists with significant challenges. Dental caries is highly prevalent in adults over 65 years, and new care paradigms for older adults are discussed in this paper.

By Professor Finbarr Allen

It has now become established that life expectancy is steadily increasing, with the proportion of adults over the age of 65 years (older adults) showing the most rapid growth[1]. The rate of change in the age profile shows some variability among EU countries, but there is little doubt that, overall, the European population is ageing. This can be attributed to a number of factors, such as greater awareness of lifestyle and its relationship to health, and improved technologies for managing disease. Chronic disease, including oral disease, continues to be prevalent in older adults, and its management is costly and challenging for society in general and healthcare professionals in particular. Complex interactions between chronic oral disease processes such as periodontal disease and systemic disease (e.g., diabetes) are evident, but the precise nature of these interactions has yet to be fully elucidated. Of further relevance to this topic is the attitude of older adults to oral healthcare, and whether or not they are domiciled in residential care or living independently. This paper provides an overview of the issues facing policy makers and oral healthcare professionals in providing oral health care for an ageing population. For the purpose of the paper, the term “older adults” refers to anyone over 65 years of age.

Oral health trends
In terms of oral healthcare, perhaps the most dramatic change has been in tooth retention rates[2]. National oral health surveys across the globe strongly indicate a dramatic decrease in the prevalence of total tooth loss, or edentulism. However, dentate older age cohorts tend to exhibit high levels of dental disease, particularly dental caries (both coronal and root surface caries). Furthermore, older adults are at higher risk of developing mucosal disease, particularly oral cancer. The disease pattern is linked to lifestyle choices such as a high sugar diet, cigarette smoking and alcohol consumption. Exposure to these risk factors accumulates over time, and the burden of disease and maintenance increases with age. The risk of total tooth loss at an advanced age in life has therefore increased, and the timing of being rendered edentate has shifted from middle to old age. This increases the risk of maladaptation to wearing complete dentures, and thus treatment planning strategies for maintaining sufficient numbers of natural teeth are required.

The principle challenges for the future include the following:
1. Managing the burden of cumulative effects of chronic oral disease
2. Reducing the risk of total toot hloss, and when total tooth loss is inevitable, ensuring the transition to the edentulous state is carefully planned
3. Developing evidence-based, cost effective treatment strategies for dentate older adults
4. Managing expectations

Managing oral disease in older adults
Regular screening of older adults is advocated, with a particular focus on screening for dental caries, periodontal disease and mucosal disease. Managing disease in older adults can be complicated by their medical status, and clinicians need to recognise the interaction between medical conditions, treatment for those conditions, and oral health status. For example, salivary flow in older adults is frequently compromised and predisposes the patient to oral discomfort, halitosis and dental, periodontal and mucosal disease [Figure 1]. Xerostomia can be due to reduced efficiency of minor salivary glands as a result of ageing, secondary to pathological processes, and a side effect of medications to manage systemic disease. Commonly used medications which predispose a patient to xerostomia include antihypertensives (e.g., ACE inhibitors, Beta blockers), diuretics, daily aspirin, antidepressants and anxiolytic medications. The effects of xerostomia can be moderated by measures such as saliva substitutes (e.g., Biotene), but adequate plaque control measures are vital to reduce the risk of periodontal disease and dental caries.

Periodontal disease is prevalent in approximately 15% of the adult population, and periodontal attachment loss is higher in older adults. The age of the patient is not a critical factor in determining the outcome of treatment, and a favourable response to appropriate plaque control and non surgical treatment is possible in healthy older adults. This includes the usual protocols for maintaining an adequate standard of oral hygiene, but this needs to be suitably tailored for an older patient. In some cases, manual dexterity may be compromised and it may be of value to encourage the patient to use an electronic toothbrush. A useful alternative is to modify the handle of a standard toothbrush to aid handling, and this can be achieved using foam or rubber bands [Figure 2]. Interdental cleaning aids are also of value, although recommendation needs to be mindful of the patient’s manual dexterity. Ideally, aids with handles (e.g., TePe brushes) are recommended. Oral mouthrinses (particularly those containing Chlorhexidine, e.g. Corsody) can be of value, but patient compliance is often an issue. In some cases, they can be a useful adjunct in the management of dry mouth (xerostomia), which has a higher prevalence in older adults. In addition to mechanical plaque removal, mouthrinses may help to reduce the pathogenicity of plaque in the absence of good salivary flow.

Managing dental caries in older adults continues to be a significant challenge. Despite improvements in oral health, reduction in decayed missing, filled (DMF) statistics has been substantially less in adult cohorts over the age of 65 years than younger cohorts in nearly all reported national oral health surveys. A high prevalence of dental caries is found among old-age populations in several countries. The available data worldwide show that dental caries is a major public health problem in older people and closely linked to social and behavioural factors[2]. Root caries has been associated with a number of factors, including denture wearing, smoking, periodontal attachment loss and xerostomia [Figure 1, 3].

In recent years, a minimally invasive approach has been recommended to reduce the burden of maintenance in older adults, and to deal with the often unfavourable circumstances peculiar to older adults [3]. These include problems of compliance with oral hygiene instructions, occurrence of dry mouth, difficulty controlling moisture when restoring carious lesions, and the ability of patients to co-operate with treatment (e.g., patients with dementia). Minimally invasive dentistry is underpinned by modern philosophies guiding caries management, and the development of suitable preventive and adhesive materials. A key element is identifying the level of caries risk and implementing a tailored preventive regime. In addition to oral hygiene procedures described earlier, the use of chemotherapeutic agents to retard caries progression and remineralise carious dental tissue may also be indicated. This includes the use of products with a high fluoride content (e.g. 5000 ppm) and CPP-ACP (Casein Phosphopeptide - Amorphous Calcium Phosphate; GC MI Plus, Recaldent).
 
In recent years, techniques such as stepwise caries removal and restoration with bioactive materials have been developed to control caries progression [4]. Preservation of tooth tissue is paramount, and glass ionomer cements (both conventional and resin-modified) are utilised given their bond strength to dentine and the potential for leaching of fluoride. Low viscosity glass ionomers have been developed that perform well in a wet environment (e.g., GC Fuji Triage), which may be very useful in cervical areas where moisture control is challenging [Figure 4]. Use of atraumatic restorative treatment (ART) has been successful in children and adolescent populations, and has been developed as a pragmatic treatment strategy for controlling the progress of dental caries. ART involves the removal of carious tissue with hand instruments only and filling of the resultant cavity with an adhesive restorative material such as glass ionomer cement or resin-modified glass ionomers. This approach may be of benefit in circumstances where rotary instrumention and trituration equipment are not available, e.g. in the care of elderly patients in residential care homes.

When considering approaches to the management of tooth loss, the propensity for caries development should influence the design of removable prostheses to replace missing teeth. The risks associated with provision of removable partial dentures (RPDs) should be considered, and whether they are outweighed by the potential functional and aesthetic benefits in replacing missing teeth. The shortened dental arch (SDA) concept adopts a functionally oriented treatment planning strategy, with missing teeth only being replaced with a prosthesis if there is likely to be a benefit to oral function or appearance, or to help prevent occlusal instability via uncontrolled tooth movements [Figure 5]. Anterior and premolar teeth are seen as essential in this regard, with less importance attached to replacement of missing molar teeth. The main relevance of this is whether or not to restore missing molar teeth with a removable partial denture. In addition to the aforementioned potential for RPDs to damage teeth, there is substantial evidence of non compliance with wearing dentures, particularly those that only replace missing posterior teeth in the mandible (e.g. bilateral unbounded saddles). It appears from the available evidence that shortened dental arches restored with RPDs do not improve oral comfort or chewing ability to any significant degree when compared with unrestored shortened dental arches or those extended using cantilevered fixed bridgework[5]. However, and critically, the incidence of new disease in shortened dental arches extended using RPDs is substantially higher, and this has led to a re-evaluation of the benefit of providing RPDs to replace missing posterior units in older adults.

Finally, managing patient expectations is likely to be increasingly challenging in the future. Whereas older patients were once quite prepared to accept total tooth loss as part of the ageing process, they are much less likely to do so now. Access to information about treatment options has broadened, and it would appear that older adults are much more likely to seek treatment aimed at preserving teeth rather than accepting dental extractions. Furthermore, removable prostheses can be associated negatively with ageing, and older adults may demand more fixed options in the future.

In terms of advocacy, the recent literature linking oral disease to the pathogenicity of life threatening illnesses such as cardiovascular disease is potentially important. The evidence of association via common risk factors between cardiovascular, respiratory, metabolic disease and oral disease illustrates the value of good oral health. Further work is required to more fully elaborate on the mechanisms of interaction, but the importance of oral disease prevention on overall health cannot be ignored by health policy makers.

Conclusion
As patterns of disease prevalence are changing, and dental disease remains highly prevalent in older adults. As the proportion of older adults steadily increase, the burden of oral healthcare requirement will also increase. This has implications for the financing of oral healthcare for older adults. Pragmatic, evidence-based approaches have been introduced in response to these developments, and a minimally invasive approach to restorative dental care would appear to be appropriate for older adults. Preventive care needs to be tailored for older adults to take into account manual dexterity and the impact of co-existing medical conditions.
 
References
1. World Health Organization. Global review on oral health in ageing societies. Age and Health Technical Report; 3 WHO Kobe Centre for Health Development, October 2002.
2. Petersen PE. The World Oral health report 2003: continuous improvement of oral health in the 21st century – the approach of the WHO Global Oral Health Programme. Community Dent Oral Epidemiol 2003; 31(Suppl. 1): 3-24
3. Chalmers JM. Minimal Intervention Dentistry: Part 2. Strategies for Addressing Restorative Challenges in Older Patients. J Can Dent Assoc 2006;72(5):435-40.
4. Mount GJ. A new paradigm for operative dentistry. Aust Dent J 2007;52:264-70.
5. Jepson NJ, Moynihan PJ, Kelly PJ, Watson GW, Thomason JM. Caries incidence following restoration of shortened lower dental arches in a randomized controlled trial. Brit Dent J 2001;191:140-4.

The author
Professor Finbarr Allen BDS PhD MSc FDSRCPS FFDRCSI
Professor of Prosthodontics and Oral Rehabilitation
Cork Dental School and Hospital
Wilton, Cork, Ireland
e-mail: f.allen@ucc.ie