How can the elderly's real need to restore missing teeth be uncovered?

The following aspects are usually relevant and ought to be considered: Patients can hardly be expected to express their real need and how it may be satisfied without a full understanding of possible treatment options. These are determined by the dentist after a thorough clinical examination. In the subsequent dialogue between patient and dentist, these options, with relevant advantages, disadvantages, financial consequences, risks and prognoses need to be discussed and explained. However, the dialogue should be no more extensive or complicated than necessary for its purpose.

It must be taken into account that many elderly regard the dentist as an authority figure, whose concept of optimal prosthodontic treatment based on the dentist's superior knowledge and experience may be difficult to challenge. However, usually several treatments are possible, and it is important that the dentist's preference is not presented so strongly that the patient's subjective need becomes obfuscated.

Relevant to this discussion is the clinical experience that the subjective needs of the elderly may be less demanding than those of younger patients, and deviate significantly from more «objective» optimal treatments suggested by the dentist. In contrast, a few patients may insist on restorations that are not in accordance with generally accepted standards. In the latter case, even if the patient is adamant, the advice is to refrain from treatment, because the dentist carries the responsibility for any treatment provided.

Only after deliberations like those mentioned above, is the patient able to give «informed consent» to the chosen treatment as specified by law and ethics. Informed consent by frail elderly persons may be complicated by declining mental ability. Tiredness or early dementia may cause communication problems that may be reduced with the assistance of a family member or an emphatic friend. If dentist and patient have had a long-standing professional contact the decision-making is greatly simplified.

What may be obstacles to optimal treatment of elderly?

Of particular prosthodontic interest in this respect is the reduced ability by some elderly to endure long-lasting and multiple appointments - particularly associated with complex treatments. The lack of endurance may be related to general failing health and somatic diseases, but also to reduced mental stamina or other psychosocial circumstances. Even when this problem does not apply, conditions like shaking or rigidity or reduced muscular function in patients with motor symptoms or conditions that preclude prolonged periods of sitting still in a dental chair, may denote insurmountable obstacles for complex treatments.

Lack of funding may also prevent preferred treatment. Although all Nordic countries have some degree of public funding for dental treatment, the systems and traditions differ significantly (8,9). Thus, prosthodontic treatment is to a significant extent publicly reimbursed in Sweden. In Norway, with few exceptions, only two-implant retained overdentures are fully reimbursed. In Denmark and Finland, also with a few exceptions, no such treatment is reimbursed.

The elderly use dental services less than younger adults even though their treatment needs are more complex (10). Furthermore, the cost of prosthodontic treatment and the level of public funding may influence the use of oral health care services for elderly (11), the choice of prosthetic treatment (12) and OHRQoL (13).

When are simplified methods and materials justifiable in the elderly?

There are numerous types of simplified methods and materials that may be indicated for elderly in specific situations. Examples are composite crowns, (as opposed to conventional crowns), fibre reinforced fixed dental prostheses (FDPs) also called bridges (as opposed to conventional FDPs) or resin bonded metal (usually chromium cobalt) FDPs. Their advantages are that they can be accomplished in shorter and fewer appointments compared with conventional methods. Composite crowns may perhaps not last as long as conventional crowns, but are still acceptable in suitable cases. Fibre reinforced FDPs are shown to have reasonable longevity as demonstrated in multicentre studies (14,15), and in suitable cases are certainly preferable to partial removable denture prostheses (PRDPs). Resin bonded metal FDPs with prepared mechanical retention have longevity comparable to conventional FDPs (16).

Simple acrylic PRDPs with wrought wire retentive clasps (as opposed to PRDPs with metal framework) are always contra-indicated, except as temporary restorations, because of convincing documentation that long-term use causes irreversible harm to oral tissues, reduced function and poorer prognosis of the dentition.

Patients with problems like those described above may be particularly suited for simplified methods and materials. Regrettably, unacceptable restorations like acrylic PRDPs are too often used indiscriminately in the elderly because they are inexpensive, expedient and may seem to satisfy short-term needs. Considering the dire consequences on oral tissues and loss of OHRQoL, in some cases such dentures may even be more expensive than alternative treatments. Furthermore, the use of ESDAs may sometimes be the best treatment for the target group if it satisfies the limited subjective need of the patient. Even if it does not, nothing is ever lost by employing ESDA. Thereby time is gained and an extension of the dental arch by whatever means can always be implemented later if indicated.

What about prosthodontic treatment when oral diseases cannot be completely controlled?

Infected teeth or retained roots and other conditions that cause pain and acute infection, must always be resolved before prosthodontic treatment. However, elderly may also have an increased risk of root caries, periodontitis, stomatitis or implantitis that can be quite resistant to treatment. These conditions may be successfully treated in the short term and prophylactic measures implemented. Still, in this age group they often relapse, due to factors like hyposalivation, reduced host resistance and sometimes inability and reluctance of the elderly to carry out adequate oral hygiene regimen. The ideal is that oral tissues should be free from disease before restorative treatments are undertaken. If this is not achieved, a significant proportion of this group will not be able to enjoy the benefits of restorations, with corresponding loss of OHRQoL. Compromising this ideal should never be made lightly, but must be justified after careful consideration of each individual.

Examples of the dilemmas such problems pose in regard to prosthodontics are apical pathology with few or no subjective symptoms, slowly developing periodontitis or treatment resistant stomatitis. A necessary condition for undertaking prosthodontics is then that possible harmful consequences are considered to take too long to be of major importance compared with the advantages gained.

In all such cases a professional maintenance regimen needs to be implemented. This must be individualized and controlled so that failure of the patient to attend is recognized. Then the patient should be routinely, and if necessary repeatedly, contacted. If unsuccessful, contact with family members may be attempted.

If the above measures are not implemented, the short-term benefits in the frail elderly may rapidly be offset by adverse effects. Whether or not to undertake prosthodontic treatments under these conditions pose difficult ethical and professional dilemmas for the dentist.

How can the need for repairs of fixed restorations be minimised?

In the reduced dentitions in SDA or ESDA the biting and chewing forces load fewer teeth than in dentitions with more teeth. The resulting heavy loading on remaining teeth and abutments necessitates adequate dimensioning of the metal constructions. Also, strong retention needs to be carefully considered. Night guards may counteract some of the problems.

The increased risk of root fracture of endodontically treated abutments with posts and cores is reduced by furnishing such teeth with solid ferrules embracing the root. Endodontic treatment through a crown is sometimes necessary, but this procedure reduces the strength of the dentin preparation with resulting high risk of loss of retention or fracture of tooth substance. Minimal entrance to pulpal chamber and root canal should be sought in order to reduce these risks. Preparation for and insertion of a post in such cases, which may be considered after root canal treatment, in fact further reduces the mechanical strength of the tooth.

Repair or renewal of existing prostheses?

Maintenance of existing restorations in the elderly may be equally and sometimes even more important for preserving oral function than constructing new ones. To this end, the need for regular, systematic recalls and implementing measures when needed cannot be stressed enough. This is particularly important in regard to PRDPs due to their potential for tissue harm.

When problems do occur, deciding whether to repair, adjust, renew or leave well alone is difficult. Adapting to new prostheses may be problematic for an elderly person, particularly if the intervention alters the denture's external shape. However, some interventions are less risky than others: repairing fractured retention clasp arms of a PRDP, fractured denture teeth, fractured acrylic base if the fragments can be accurately positioned or extending the denture when a natural tooth is lost, certainly fall within this category. Fractures of an acrylic denture base caused by material fatigue - typically in the midline of CRDPs, should not be repaired because such defects inevitably recur. Rather, a rebasing or a new denture is the treatment of choice.

Relines of PRDPs or complete removable dental prostheses (CRDPs) may extend the lifetime of the dentures. With PRDPs, relines should only be attempted if the general fit of the metal framework is acceptable and all metal components are functioning. Relining CRDPs serves no purpose unless aesthetics and occlusion are acceptable.

Unfortunately, patients must manage without removable dentures during laboratory assisted repairs, although the time needed to carry them out may be reduced by careful preplanning. If the alternative to repair is making a new denture, the patient has to decide whether this disadvantage is worth the cost and possible adaptation problems incurred in receiving a new one.

If an existing denture must be remade, it may be an advantage to make use of the duplicate denture technique in which internal and external surfaces of the existing denture are replicated (16), which is then used as a basis when constructing a new one. This method hopefully reduces the risk of rejection. Also the original denture is intact and can be reinserted if the patient cannot adapt to the new one.

Mechanical breakdowns of FDPs are rare. A possible exception is broken facings, which can mostly be polished or repaired with composites. The most common causes of failure of fixed constructions are root caries or periodontal breakdowns of the abutments. Consequently, prophylactic measures are of crucial importance for maintaining FDPs in function. If the abutments have fractured or the retention of the FDP is lost on one or more abutments, repairs are usually technically very complicated, impractical or impossible to perform. Then, a new appliance has to be fabricated or the existing one shortened.

Fixed or removable - a key question

As intimated earlier, in guidelines for public funding, including those that exist in Nordic countries, FDPs are still, implicitly or explicitly considered an exclusive, expensive and «unnecessary» treatment. The preferred alternative, no doubt mainly for economic reasons, is PRDPs. This preference is also shared by many colleagues and health care planners who claim that FDPs are more expensive, technically challenging and difficult to keep clean. (4, 18). However, compared with FDPs, PRDPs substantially add a risk of mechanical damage to gingival tissues, plaque retention and dental caries (Fig. 1) (19,20). It has also been reported that up to 40 % of PRDPs are rejected by the patients soon after insertion, indicating a low patient acceptance and reduced OHRQoL of such constructions (21). Furthermore, it has recently been shown that patients prefer to have missing teeth restored by FDPs» (22).

If the SDA and ESDA concepts are followed, gaps in the anterior dentition are often small. These are more adequately closed with FDPs, which are mostly easy to produce, carry a minimal risk of harmful consequences and are better accepted than PRDPs. An implant supported crown may also suffice to close the gap. In suitable cases the use of a simple two-unit cantilever FDPs (one abutment/one pontic) can be justified (Fig. 2), even when used to extend the dental arch posteriorly, as documented in prosthetic literature (19,20,23). A similar distal extension can also be accomplished with an implant supported crown. Such treatment may be especially valuable for the elderly who have retained natural teeth to a high age and who may experience great problems adapting to a PRDP with a resulting reduced OHRQoL.

Furthermore, keeping in mind the SDA and ESDA concepts, the laboratory cost and clinical time required in order to restore such a dentition by means of an FDP may sometimes be equal to or lower than a high quality PRDP counterpart (Table 1), which requires much time for construction, clinical adjustments and follow-up (Fig. 3) (24). This was demonstrated in a recent Irish study (25) where laboratory costs were 38 % higher for the PRDP than the FDP. Also, initial clinical visits, follow-up appointments and total clinical time were on average 48 % higher for the PRDP group. True, the FDP patients had an average of just 2.6 replaced in order to satisfy the SDA requirement whereas the PRDP replaced 6.3 teeth. However, the added teeth of the PRDPs were a consequence of the construction, had little therapeutic value and did not enhance the OHRQoL as demonstrated in a large multicentre study (26).

Based on the above, it can be argued that the current preference for PRDPs, has resulted in a longstanding overproduction of such appliances. The reduced risk for tissue injuries, less demanding long term maintenance, patients´ preference and improved OHRQoL, strongly suggest a more liberal use of FDPs - particularly when restoring minor gaps in the anterior region. The type of crown for retaining a fixed restoration is in this context of lesser importance.

Implants for the elderly?

A complex or unsatisfactory prosthetic treatment may be changed to a simple and effective one by the use of implants. The construction will then be technically safer, have better oral function and may easily improve OHRQoL in an elderly patient. One cost-effective example for patients unsatisfied with their mandibular complete denture is the insertion of two implants with ball attachments retaining an overdenture (27). Age as such does not affect implant survival (28,29). However, there may be surgical, medical, psychological and financial aspects that limit the use of implants, particularly in frail patients.