1

Introduction

Despite many advances in prevention, oral health education, improved oral hygiene practices and the availability of fluoride, the management of caries, via the placement of restorations, remains a significant component of the day-to-day work of the dental team. Despite efforts to reduce the effects of caries, population-based studies reveal that the prevalence of caries remains stubbornly high. An example of this is seen within the United Kingdom population, where 84% of dentate adults were found to have at least one restoration [ ]. Of these adults each had, on average, 7.2 filled teeth. Such figures are of concern when one considers the dental maintenance requirements of these patients, particularly as each restoration will require periodic intervention and management, let alone when one considers that the longevity of dental restorations in primary dental care settings is poor. Analysis of the survival of dental restorations from within a large database of dental treatments within UK dental practice reveals that further intervention is required [ ]:

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  within 11% of fillings after 1 year of placement

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  within 20% of fillings after 3 years of placement

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  within 50% of fillings after 10 years of placement

It is easy to appreciate that all restorations will ultimately suffer deterioration and degradation leading to the need for further intervention [ ]. Reasons for this can include marginal defects, secondary caries, fracture of the restoration or adjacent tooth substance and, in the case of tooth-coloured restorations, unacceptable appearance [ ]. However, the decision to intervene in an existing restoration may be highly subjective on the part of the operator: factors such as the age of the patient, the size and location of the restoration can influence the rate at which existing restorations receive further intervention, as can changing dentist [ ]. As such, there is potential for over-treatment. The risk of iatrogenic effects with over-treatment, notably the needless replacement of existing restorations, are significant, and often associated with the inevitably unnecessary loss of intact, healthy tooth tissue. Over the course of a lifetime, many such interventions cause great harm to a tooth, descending the so-called “restorative death spiral” [ ]. If a patient has a number of teeth irretrievably slipping down this spiral, the effects on the dentition may be many and varied, including a progressive deterioration in dental attractiveness and loss of occlusal function, possibly influencing quality of life. Also, lifetime cost of dental care may be substantially increased.

Almost 20 years ago, a review [ ] of studies with similar methodology reported that replacement restorations accounted for 56% of restorations placed by dentists. This review included studies performed between 1981 and 1998, and aggregated their findings. Since then there have been many changes in the approaches to the restoration of teeth. These include:

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  enhanced understanding of when it is necessary or, more precisely, not necessary to intervene in existing restorations.

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  a greater understanding of the concept of restoration repair where, in the presence of secondary caries or fracture, it is possible to perform a localised repair rather than unnecessarily removing the restoration in its entirety.

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  an increased use, matched by predictability, in the use of adhesive dentistry techniques, particularly the application of resin composites (composites) in posterior teeth.

As such, it was considered useful to expand the previous review to include studies completed since 1998, and to investigate, in particular, if patterns of placement/replacement restorations have changed. Therefore, the aim of the present study was to review relevant papers with a similar methodology published since 1981 and to consider the effects, if any, of recent changes in the approach to the restoration of teeth and management of already-restored teeth.

2

Methods

For the purposes of this review, studies based around the protocol of Mjör 1981 [ ] were selected. Such studies involved participating dentists completing a proforma each time a patient presented for a new or replacement restoration over a period of time. Dentists were asked to record all restorations placed, and indicate the main reason for the initial placement or replacement from a set of options.

Studies that did not include the selected methodology were excluded. Also, studies were excluded if they reported on reasons for placement only, restorations for anterior teeth only, or if it was not possible to separate data pertaining to different types of restoration.

Studies were identified using searches of electronic databases, as well as hand-searching of the literature, including the reference lists of related and similar studies. The search was last updated in September 2017.

The data sought was extracted from the reports of the selected studies and collated for analyses and comparison.

2

Methods

For the purposes of this review, studies based around the protocol of Mjör 1981 [ ] were selected. Such studies involved participating dentists completing a proforma each time a patient presented for a new or replacement restoration over a period of time. Dentists were asked to record all restorations placed, and indicate the main reason for the initial placement or replacement from a set of options.

Studies that did not include the selected methodology were excluded. Also, studies were excluded if they reported on reasons for placement only, restorations for anterior teeth only, or if it was not possible to separate data pertaining to different types of restoration.

Studies were identified using searches of electronic databases, as well as hand-searching of the literature, including the reference lists of related and similar studies. The search was last updated in September 2017.

The data sought was extracted from the reports of the selected studies and collated for analyses and comparison.

3

Results