Endodontics and the older patient

General factors

The older patient tends to retain teeth which are likely to be compromised in terms of the age-related pathological effects of caries and periodontal disease. The physiological effects of tooth surface loss, if slowly progressive, will result in loss in anatomy and pulpal changes, such as the formation of pulp stones and narrowing of the root canals. Caries incidence may increase due to dietary changes, reduced salivary flow and a reduction in manual dexterity and often manifests as cervical and recurrent caries in the older patient. In the older adult with a heavily restored dentition, maintenance can be less than ideal due to medical and dietary factors, possibly a reduction in salivary flow and reduced mobility which could affect the frequency of attendance. Pulp vitality is increasingly likely to be compromised.7 Therefore, in the older patient, when it is advantageous to retain teeth, the challenges in providing endodontic treatment can be considerable.

In the older patient, it is a common situation for only a few teeth to be remaining. Partial dentures are not always well tolerated, especially a lower partial, so maintenance of strategic teeth, such as the lower molar, which may be the distal abutment to a free end saddle, is advantageous. The typical scenario may be that of a retained lower second molar which is broken down and the canals appear to be sclerosed. Implants may well be contra-indicated. The technical challenges of endodontic treatment may be considerable and lengthy appointments may not be possible. An additional consideration is that root-treated teeth must be well maintained. If this is a problem, then consideration of an over-denture may be sensible.8 Another approach would be to adopt the shortened dental arch concept and accept that a lack of molar teeth does not significantly affect function and aesthetics.

The majority of elderly patients are compliant and happy to undergo treatment. It is important to ensure that the patient has been advised about the procedure and be made to feel comfortable if he/she suffers from arthritis or chronic back conditions. If compliance is poor, for example, in those suffering from dementia, then endodontic treatment is probably contra-indicated.

Interestingly, it has been shown that dentists significantly underestimate their older patients' willingness to undergo dental treatment, so it is important not to embark upon treatment planning for this group with a pre-conceived idea about their expectations.9

Medical history

A thorough medical history should be taken and updated on each occasion. If there are any uncertainties regarding the general health of the patient, or if endodontic treatment may have an effect on the patient, then the general medical practitioner or consultant should be contacted.

Medical problems that may have an influence on treatment include:

The tooth

Another article in this series deals with age-related changes in the oral tissues and the reader is advised to refer to this as background reading.2

Teeth usually darken with age, this being attributed to an increased thickness of the underlying dentine.

Dentine

Regular secondary dentine is deposited in the pulp horns throughout life. In molars, deposition occurs on the floor and roof of the pulp chamber, the outcome of which is that the pulp chamber becomes reduced. If there is marked toothwear, deposition of reactionary dentine and reparative dentine the pulp chamber may become almost obliterated. In Figure 1 there is marked tooth surface loss associated with the labial and incisal aspects of the lower central incisors. In this situation, visual identification of the canals is relatively easy. Figure 2 illustrates a similar situation but, in this case, tooth surface loss appears to have progressed more slowly and identification of the canals may be more problematic. Note also the hairline fracture in the lower left central; this could propagate throughout the length of the tooth and deem it unrestorable.

This results in the root canal pattern becoming more complex and more of a challenge to negotiate. More apically, the canals may remain patent. Figure 3 shows a heavily restored upper left second molar tooth. This tooth has become symptomatic; there is a large intracoronal restoration in close proximity to the pulp and the canals appear to be partially obliterated. An extraction would be a sensible approach for this patient.

Pulp

As the tooth ages, the pulp tissue becomes less vascular. Calcifications (eg pulp stones) are commonly found, mainly in the coronal aspect, less so more deeply. As the pulp becomes less vascular, it also becomes less sensitive. The tooth may become dry and prone to fracture; care must therefore be taken during placement of a rubber dam clamp when microscopic fracture lines are seen. Figure 4 illustrates age-related changes in terms of loss of periodontal support, reduction in size of the pulp chamber and narrowing of the root canals related to the second molar.

The diagnostic dilemma

History-taking may be challenging in the older patient, who could be hard of hearing or cannot give a clear history. If there is a presenting complaint of pain, then accurate identification of the cause may be problematic, particularly if the dentition is heavily restored and teeth are crowned. Diagnostic tests such as vitality testing are useful, but in teeth in which the pulp has reduced vascularity and, in addition there is an increase in the thickness of dentine, interpretation may be difficult. The history will give some indication as to the general site of discomfort. Clinical examination should follow best practice and include a general assessment of the hard and soft tissues, and the presence of any sinuses or swellings noted. There should be an evaluation of the occlusion. Individual teeth should be carefully examined using good illumination and with the teeth thoroughly dried. Careful examination of the crown of the tooth, a record of its colour, presence of caries or hairline fractures, the adequacy of any restorations and the periodontal status will indicate any relevant pathology at this stage.

The outcome of vitality testing is often inconclusive but may yield useful information.

A high quality, periapical radiograph should be taken of all teeth which are being considered for endodontic treatment. From this it is possible to derive useful information additional to any apical bone changes, such as the number and curvature of the roots, the size of the pulp chamber, presence of pulp stones and the patency of the canals. The depth of the pulp chamber can be estimated and this information is useful when the access cavity is prepared. It is good practice to share the radiographic findings with the patient and to discuss any anticipated difficulties.

At this stage any defective restorations/caries should be removed in order that the restorative status of the tooth can be accurately assessed.

Relevance of the tooth

Sensible treatment planning is critical for the elderly patient and certain teeth may be regarded as strategic in preserving function, such as acting as partial denture or precision attachment abutments. Even roots which have not been root-filled in which the canals are sclerosed and do not exhibit apical pathology will assist in the maintenance of alveolar bone.

Examples of particularly strategic teeth are:

In Figure 5, the lower left second molar is a strategic bridge abutment. The root canal treatment was carried out 15 years ago. The tooth is asymptomatic so, although there are apical bone changes associated with both root apices, it would be sensible to keep the tooth under clinical and radiographic review. Figure 6 shows the upper arch of a patient who has a cleft palate and wears an upper partial denture. Clearly, preservation of the upper left canine and left molar teeth would be preferable.

Restorability

Before endodontic treatment is commenced, it is essential that plans for a definitive restoration have been made. Endodontic treatment is contra-indicated if:

Extraction may be indicated in these cases.

Why root treat; why extract?

The resumé below will give an indication as to the relevant points to be considered when a tooth with a terminal pulpitis/non-vital tooth is to be root-treated or extracted.

Vital pulp therapy

Vital pulp therapies include the following.

Pulpectomy

A pulpectomy is the treatment of choice when the prognosis for pulp survival is questionable. It will also eliminate the possibility of later pulpitis. Careful consideration of the clinical information derived from the disease history and clinical examination is essential for a sound decision to be made.

Although not consistently observed, it seems that the prognosis for pulp capping and partial pulpotomy are better in younger than older individuals.10 A recent randomized clinical trial found that the prognosis of direct pulp capping and pulpotomy are far less successful in maintaining pulp vitality than step-wise excavation followed by indirect pulp capping.11

Young teeth have a good blood supply and are more likely to respond well to pulp capping procedures, older teeth less so. Often, a decision will have to be made as to whether an attempt should be made to re-treat the tooth, especially if the existing root treatment is less than ideal. It would be advisable to keep such a tooth under regular clinical and radiographic review if it is asymptomatic, but if symptoms supervene, then re-treatment should be considered. Figure 7a shows the radiograph of a lower molar tooth which has been treated endodontically in the past. The patient now has symptoms and it was agreed that re-treatment should be attempted. Fortunately, the canals beyond the apical end of the existing root-filling could be negotiated and were cleaned, shaped and filled (Figure 7b). By contrast, in Figure 8 the canine is grossly carious and an extraction would be sensible. However, the patient has Alzheimer's and reduced manual dexterity, so it was agreed that an attempt at endodontic treatment should be made. In this respect, isolation may be complicated for isolated decoronated teeth.

Clinical management

Placement of a rubber dam, access cavity creation and canal(s) location is the most difficult stage in endodontics especially in the older patient. The fundamental rules related to best practice should be followed and removal of caries and creation of a sterile field should be achieved. Occasionally, it may be necessary to engage undercuts or remove gingival tissue for rubber dam retention. Good illumination, magnification, use of a microscrope and a front surface mirror are useful. Safe-ended access burs and ultrasonic tips can facilitate removal of the pulp chamber roof and canal location. Creation of the access cavity prior to dam placement can be helpful if a prosthetic crown is present. Reference to the pre-operative radiograph will help determine the depth of the pulp chamber. If the pulp chamber cannot be located, then a location radiograph is useful to give information about the angulation and depth of the access. Use of long shank, narrow neck burs (eg Maillefer LN pin – Figure 9a and Meissenger goose neck – Figure 9b) allow light to fall on the cutting end of the bur at all times. Observation of the floor of the cavity for features such as altered colour and translucency in the form of a white spot indicate the former pulp space and facilitate canal location. A DG16 probe (Figure 10) is useful when used to locate sclerosed canals. In extremely calcified canals the only way of effectively negotiation is often the use of a size 6 or 8 file (Figure 11) in conjunction with a chelating agent such as EDTA. Figure 12a shows a pre-operative radiograph of a lower first molar tooth, the canals of which appear to be narrow. However, with the careful use of good access, using small files in conjunction with a chelating agent, the canals were shaped and filled successfully (Figure 12b).

Shaping techniques

The fundamental principles of canal cleaning and shaping remain the same. A wider access cavity will allow better vision and improved straight line access. EDTA in either a gel or liquid form may be useful in narrow canals in conjunction with small files. It is often difficult to see into deep cavities, especially if access is created through a metal ceramic crown or deep amalgam restoration. Use of magnifying loupes, fibre optic hand-pieces and long shank burs together facilitate vision. The use of an apex locator enables the patient to remain in one position, rather than having to move to have diagnostic radiographs taken. Use of a mouth prop could be considered in patients who find it uncomfortable to keep their mouths open for long periods of time. A perforation on the floor of the pulp chamber may be created in an attempt to locate the canals and a decision must be made as to whether or not the tooth can be saved. Use of an apex locator facilitates confirmation of the presence of a perforation site. Treatment options include an extraction, to cover the perforation site using mineral trioxide aggregate or a zinc oxide eugenol containing material and then continuation of the endodontic treatment, or referral to a specialist practitioner. The shaping of very narrow canals requires care to prevent file separation and ensure that transportation does not occur. Use of sodium hypochlorite as an irrigant should be used unless there has been a perforation.

Obturation techniques

Again, the basic principles remain the same, ie canals should be filled with an inert material such as gutta percha to within 0.5 mm of the radiographic apex. Very narrow canals are more difficult to fill successfully, hence the need to shape to as large a size as possible, so it is advisable to have created a good coronal opening and an adequate canal shape such that it can be obturated.

Coronal seal

An adequate coronal seal is considered to be critical for success and survival of the root-filled tooth.12 If a root is to be retained as an overdenture abutment, a resin-modified glass ionomer should be placed over the gutta percha. A glass ionomer cement over the root filling followed by an adhesive restoration should be the restoration of choice. Teeth in the older patient may well have undergone significant loss of tooth tissue, so provision of a core would require placement of a post. In molars, the use of a Nayyar type of amalgam or composite core prior to the provision of a full coverage restoration is useful.