Should deciduous teeth be restored? reflections of a cariologist

No caries removal, but open the lesion to allow cleaning

This approach, first advocated by GV Black, was re-examined 5 years ago.15 It has been called non-restorative cavity treatment (NRCT) because no filling is placed.16

The rationale is to open the cavity to make it accessible for plaque control rather than to mask caries activity by filling the tooth. When the cavity has been opened, fluoride varnish is applied to the carious dentine or, in a deep and sensitive lesion, a layer of glass ionomer cement is placed on the cavity floor. It may take more than one visit to open a tooth sufficiently, depending on the co-operation of the child. The technique is shown in Figure 1. The parent is shown how to clean away the biofilm regularly with a fluoride-containing toothpaste. In time, the lesion will arrest and the deposition of sclerotic and tertiary dentine is encouraged. Both processes will decrease tooth sensitivity. It is claimed that this management is child-friendly and tolerated by very nervous patients, without the need for a local anaesthetic, and that several carious deciduous teeth can be opened for cleaning in about 10 minutes.

The technique puts the responsibility for caries control with the parent. It is not a case of: ‘I will cope with your child's caries by filling the tooth, you do not have to worry’; rather: ‘You can control caries by keeping these teeth clean.’ Even if the parents' compliance is not perfect, it is claimed that the technique slows down lesion progression so that the teeth may survive until shed. Slowing the process gives time to change parental attitudes. Counselling and/or motivational interviewing is an essential part of the technique which is remunerated in Holland.

Sealing in techniques with no caries removal

Fissure sealing over active white spot caries lesions has been practised for many years but, in 2006,17 a new technique for sealing cavitated lesions with stainless steel crowns was described, which at first seemed to break every rule in the book. A stainless steel crown was cemented, with glass ionomer cement, on to a symptomless deciduous tooth with no local anesthetic, no caries removal and no tooth reduction. The cemented crown was inevitably ‘high on the bite’ but, in time, the occlusion re-established. One study showed this to happen in 15–30 days.18 The crowns were shown to be very successful, in a retrospective analysis of the work of the one practitioner in Scotland who devised the technique. These crowns are called Hall crowns after this dentist (Figure 2).19 Subsequently, a randomized clinical trial of the technique was carried out in general practice. The technique was compared to conventional intra-coronal restorations. At the operative visit, the Hall crown was preferred to conventional restoration by patients and parents, and two-year results have shown the crown to have a better clinical outcome.20

Why might this technique work? It is known that the microflora in sealed carious dentine changes, with the predominating organisms no longer being cariogenic having been sealed from the oral environment.21 This may be important in the apparent arrest of caries progression.

Partial caries removal and restoration

The aim is to remove sufficient carious tissue to enable an effective marginal seal to be obtained before restoring with a bonded adhesive restoration which will inhibit further progression of residual caries. In the indirect pulp capping technique, most soft caries is removed, stopping just prior to exposure. This can be a difficult judgement, but the pulp's capacity to survive is remarkable. Some operators only remove the biofilm in the centre of the cavity with a rotating brush, leaving most of the infected dentine22 (Figure 3). When less caries is removed, teeth are sometimes re-entered following a period of weeks to allow further excavation prior to definitive restoration. This is called stepwise excavation.21 Incomplete caries removal, indirect pulp capping and stepwise excavation have all been shown to reduce the risk of pulpal exposure. This seems biologically logical because formation of tubular sclerosis and tertiary dentine are encouraged, both of which reduce the permeability of the dentine. This leaves the micro-organisms stressed and entombed by the seal of the restoration on one side and the reduced permeability of the remaining dentine on the other. The residual flora changes, there are fewer micro-organisms and those that remain are no longer cariogenic. One study has compared complete caries removal, guided by a caries dye, with partial caries removal. Re-entry after three months showed a similar flora, irrespective of the amount of demineralized dentine removed.23 The atraumatic restorative technique should also be considered. It was originally developed to meet the need for restorative treatment in deprived areas where there was neither electricity nor running water.24 Caries is removed with hand instruments and cavities and adjacent fissures are restored with glass ionomer cement. Class I restorations are reasonably successful but Class II restorations are prone to failure by loss or fracture of the restoration. A recent follow-up study of deciduous molar teeth, where restorations were lost, showed 66% with hard dentine. This makes the point that teeth with lost restorations have not necessarily failed (Figure 4).25 Although the technique was developed for use in situations where there is no electricity, there is no reason why it cannot be used in a conventional dental surgery. There is some evidence that children find the cavity preparation, carried out with very sharp excavators, less stressful than the use of the drill.26^,27 For this reason, the technique may be advantageous when there is dental fear and behavioural problems.

Complete caries removal and restoration

The aim is to remove all the infected carious tissue and restore the tooth to function. This approach is currently accepted as best practice by the British Society of Paediatric Dentistry,28 but can be demanding of the child and the dentist, involving local anaesthesia, use of high speed handpieces and good moisture control. The complete removal of all soft caries will often expose the pulp and pulp therapy is then required if the tooth is to be saved. Small lesions are managed with intra-coronal restorations but larger lesions are restored with stainless steel crowns, having carried out the necessary tooth reduction.

Do not restore or open the tooth, leave it as it is because teeth are temporary

Many practitioners working within the General Dental Services in the UK are not restoring deciduous teeth. The proportion of carious teeth treated by restoration fell in the 5-year-old population in England, from 24% in 1987 to 13% in 1998.29 In Ireland, where there is almost universal water fluoridation, dentists employed in the public services may concentrate resources on preventive treatments and on the treatment of the permanent dentition, rather than restoration of deciduous teeth. This unconventional management in UK and Ireland has worried many paediatric dentists,30 but has given an opportunity to assess the consequences of not restoring deciduous teeth.

In 2002 Levine31 published a retrospective analysis of the records of 481 children managed by a dental practitioner in northern England. The practice policy was to concentrate on preventive treatment but not restore deciduous teeth. Of 1409 carious teeth analysed, 18% gave pain and were extracted or treated restoratively, but the remaining 82% exfoliated without the child attending the practice in pain. The risk factors for pain and infection were shown to be the development of multi-surface lesions in younger patients, disease extending beyond single surfaces, and disease in lower deciduous molars.32 The age at which the subject first presented with decay was a good predictor of outcome, representing the time available before exfoliation for decay to progress and cause symptoms.

Retrospective analysis of the dental records of 677 children from the north-west of England, who were regular dental attenders of 50 general dental practitioners, have yielded some challenging results. These children were defined as a high risk group because they had approximal caries in their deciduous teeth.33^,34 Over 80% of carious deciduous molars and 40% of carious anterior teeth were restored by these 50 practitioners. Twelve percent were extracted as a result of pain or infection and, the younger the child when caries was recorded in a tooth, the more likely was extraction as a result of pain or infection. Over 80% of carious deciduous teeth exfoliated without the child attending the practice complaining of pain, whether filled or unfilled.

A disturbing fact was that, on a patient basis, 48% of the children experienced at least one episode of pain, irrespective of whether the teeth were filled or unfilled. The more teeth that were affected by decay, the more likely it was that pain would be recorded. This result seems to represent a shocking failure of dental care.

On the other hand, a study of nearly 7,000 5-year-olds in Scotland showed sepsis to be related to untreated decay as well as to deprivation.35 Another retrospective study36 analysed data from 5168 carious primary molar teeth from 2654 British children aged 4–5 years at baseline. The idea was to assess the effect of restorative treatment on the likelihood of carious teeth subsequently progressing to either exfoliation or extraction. Results showed filling carious teeth substantially improved the likelihood of subsequent exfoliation without extraction. The jury is out on the unconventional approach of relying on non-operative treatment alone to manage caries but, in view of how common this is in UK and Ireland, there seems an urgent need for a prospective study.