Article

Feature Article
Abstract

The global burden of ageing also presents a challenge for dentistry. Our patients are becoming older and losing their natural teeth later in life. It is widely acknowledged that advanced age alone is not a contraindication for implants; it is the chronic conditions of the older patient, the treatments and side effects, as well as concomitant functional impairment that may limit the survival and success rates of dental implants. For many chronic conditions, the evidence in relation to implant survival is lacking or inconsistent, for example in osteoporosis and diabetes. Other conditions show similar implant survival rates to younger adults. In patients having undergone radiotherapy, implant survival rates appear lower. The only absolute contraindication for implant placement is anti-resorptive therapy in the treatment of bone metastases. 

In addition to risks related to chronic conditions, functional impairment, oral hygiene, immunosenescence, and patient compliance should be considered. For example, complex sophisticated reconstructions should be simplified in good time and overdenture retention adjusted to aid autonomous denture management. The decision whether or not to provide dental implant treatment to the ageing patient, even with multiple morbidities and a complex pharmcotherapeutic regime, cannot be based on the predicted outcome in terms of implant survival or success alone. It requires due consideration of the patient’s life expectancy and the potential increase in quality of life, weighed against the morbidity of the procedure itself as well as potential adverse effects on the activities of daily life.

Introduction

Global demographic studies clearly indicate that the population profile of developed countries is one of increasing life expectancy and reducing mortality rates, producing a change towards a higher percentage of elderly people. The global population aged 60 years or more doubled between 1980 and 2017, and is predicted to double again by 2050 with the 80-plus age group tripling in that time to number 425 million persons (United Nations 2017) (Fig. 1). This is in part due to the better treatment and management of diseases, meaning that patients with chronic conditions and disability live longer. Furthermore, as a result of both organ system decline and often the side effects of medications taken for chronic conditions, they may develop further co-morbidities. This is known as multimorbidity and the increasingly long list of medications that they acquire in the management of their conditions is known as polypharmacy (Barnett et al. 2012; Lancet 2016). Polypharmacy is becoming increasingly prevalent: in the USA more than a third of patients aged 75 - 85 take at least five prescribed medications with around half also taking one or more non-prescribed medications (Qato et al. 2008).

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Fig. 1: Percentage of population aged 60 years or over by region, from 1980 to 2050. Data source: United Nations (2017). World Population Prospects: the 2017 Revision

The myriad interactions that can occur across various permutations of diseases and medications means that the impact of multimorbidity may be significantly greater than the expected sum of individual disease effects (Marengoni et al. 2011) (Fig. 2). 

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Fig. 2: Prevalence of multimorbidity among people aged 50 years and over, 2010 – 2011. Data source: WHO (2015) World Report on Ageing and Health, Geneva, Switzerland: WHO Press

Trends in the demographics of dental health indicate that tooth loss now occurs later in life, with increasing numbers of elderly patients therefore presenting for tooth replacement (Stock et al. 2015). Clinicians can therefore expect to see an increasing number of elderly patients presenting either for implant therapy ab initio or with implants placed at an earlier time in life (Schneider 2017; Schimmel 2017). These patients will require not only management of their medical conditions and allied medications but also of the cumulative impact of these factors and the burden of our treatment on their “physiologic reserve” – the ability of the individual’s overall resilience to cope with the stresses and strains of treatment, medically, physically, and psychologically. As this reserve declines, patients become more frail and are dependent on functional assistance, affecting many aspects of the provision of dental care. However, there are few studies on implant outcomes in elderly patients with common co-morbidities.

Dental implant therapy is recognized as a predictably successful treatment option and it appears that advanced age may not be a contraindication to therapy; rather, it is the medical status of the patient together with other patient- and site-specific factors that may be associated with an increased risk of implant failure. In terms of medical factors, we need to consider whether implant failure may be related to either chronic medical conditions and/or be associated with the medications taken by the patient; what may be a relative contraindication in many patients may, in combination with other factors specific to that individual, present risks that make the provision of implant treatment inadvisable. It is important to realize that the bony attachment to dental implants is not a one-time event and that the dynamic situation of bone remodeling and repair will occur in the peri-implant bone just as in the rest of the skeleton. Consequently, any disease or medication having an impact on normal bone turnover could compromise the ongoing success or survival of a dental implant and result in implant loss. Targeted cancer therapies, immunomodulation, and immunosuppressant medications may each have an effect on bone and of course on the immune response. 

The possible impact of various chronic diseases has been the subject of several systematic reviews in recent years (Scully et al. 2007; Bornstein et al. 2009; Diz et al. 2013; Donos & Calciolari 2014). There are chronic conditions that may be associated with a detrimental effect on peri-implant tissue health at either a local or systemic level (Heitz-Mayfield & Huynh-Ba, 2009; Lang et al. 2011; Heitz-Mayfield et al. 2014; Monje et al. 2017). Many chronic conditions, including stress, have been shown to induce low-grade systemic inflammation as a result of circulating inflammatory cytokines, a phenomenon known as “inflammageing”, which has been linked to conditions such as atherosclerosis and sarcopenia (Macaualy et al. 2013; Salvioli et al. 2013), and can increase the activity of inflammatory cells known to be involved in periodontal and peri-implant related bone loss.

There are undoubtedly considerations related to how implant treatment is provided - something we could perhaps consider as the “care” aspect, the holistic management of the patient during the actual delivery of the treatment. This is again multifaceted, ranging from the management of disability and ensuring comfort, through the timing of appointments in relation to medication management, other healthcare appointments, transport requirements, carers, to issues such as mental capacity.

Assessing a patient and predicting the individual risk of implant failure is an art as much as a science and may perhaps be viewed as a series of “red lights”, each highlighting a potential risk: medical, pharmacological, psychosocial, oral health, site-specific risks, and various practical aspects such as access to the proposed surgical site as well as the practicality of ongoing home-performed oral hygiene and access to professional supportive care. The more red lights, the greater the potential risk of an adverse outcome.

In the same way, the potential benefits of implant treatment may carry a different weight relative to the assessed risks: a therapy with a less than 10-year predicted success rate deemed to be inappropriate in a 30-year old patient may be perfectly reasonable in a geriatric patient, where the benefits of treatment in terms of maintaining quality of life or effective nutrition over 10 years may be much more relevant.

Detailed individual risk assessment is mandatory, as only then can the best interests of that individual patient be accurately determined.

The purpose of this paper is to highlight aspects of the knowledge currently available regarding the management of the elderly patient and to offer recommendations to enable dental implant treatment to be provided in an appropriately safe, caring, and considerate manner.