RESEARCH PRIORITIES FOR MANAGING THE RESTORATION OF POSTERIOR TEETH PAUL A BRUNTON1
I
ncreasingly, we are seeing fewer indirect restorations being provided for patients, notably for the restoration of posterior teeth. In tandem with this, there has been a growing use of direct techniques to restore posterior teeth. This change, in my opinion, appears to be primarily due to improvements in oral health, coupled with a reduction in the need for and/or prescription of indirect restorations. This may be due to increased costs associated with the provision of direct restorations and/or the scheme by which dental practitioners are remunerated for the care that they provide. The factors that underpin these clinical decisions certainly merit further exploration. Hitherto research has largely focused on indirect restorations, the use of CAD/CAM technologies and novel ways of producing indirect restorations and materials for the production of direct restorations. This research has rightly been very material and technique focused, and it is important that newer systems are appropriately evaluated. Against this backdrop, research into the priorities of improving the outcomes of direct and indirect restorations placed in posterior teeth has, to a certain extent, been ignored; this, in my view, should be a focus for future research activity. Although clinical research is difficult to perform, it is essential if we are to improve the outcomes of the treatment that we provide for our patients. Increasingly and, arguably, for some time now, the presence of caries is no longer an absolute indication for operative intervention. We have, in my view, moved towards a system of disease management for patients, who often have disease that does not require operative intervention and where the ultimate goal of treatment is not the eradication of all dental caries, the so-called surgical model of care.1
V O L 3 N O 2 M AY 2 0 1 4
However, it seems that there continues to be confusion as to when intervention (ie operative management of dental caries) is required.1 I believe that research should focus more on assessing the activity of lesions, providing evidenced-based indications for when operative intervention is required. This would be very helpful to both practitioners and patients alike. Research needs to focus on monitoring the activity of lesions not only in terms of the progression of dental caries (ie monitor the situation) but also those that would indicate operative intervention.1 This is arguably the most important decision a practitioner can take given that this initial intervention starts the tooth on its restorative career, sometimes called the restorative cycle or staircase, which can lead to the loss of a tooth. This first decision is therefore crucial, one that frequently lacks clinical evidence to support it. Equally, practitioners are uncertain as to when indirect restorations should be replaced and/or, indeed, provided. Again, evidence-based authoritative guidelines would be helpful.
The management of dental caries at its early stages is currently a topical area for research and more needs to be carried out. The use of self-assembling peptides – a novel technology, recently described – is something that might be used during the early stages of dental caries, the socalled white spot lesion.2 Such technology needs to be rigorously evaluated to test for efficacy.
1
Paul A Brunton
Professor of Restorative Dentistry, University of Leeds
47
RESEARCH PRIORITIES FOR MANAGING THE RESTORATION OF POSTERIOR TEETH
In recent years much research has focused on dentine adhesive systems or dentinebonding agents, specifically for use with resin composite in the restoration of both anterior and posterior teeth. Many studies have looked at bond strengths and microleakage, and the hybrid layer has been studied in great detail. Going forward, I think research needs to focus on two areas: • Increasing the resistance of collagen within the hybrid layer to the enzymes active within dentine and cross-linking agents to improve the resistance of collagen to these enzymes. • The reduction in enzyme activity in tandem with initial research, which has proved interesting, that has looked at remineralisation of the hybrid layer. Further work needs to focus on this. We must not lose sight, however, of the need for clinically relevant research and the fact that a significant amount of research in this area has little clinical relevance, in my opinion. I am minded to think of the many posters, lectures and research papers that I have seen over the years at research meetings looking at newer materials and microleakage and investigating new dentine adhesive systems: I ask myself, what effect this has actually had on improving outcomes for patients? If I am honest, the answer is ‘very little’. This is not to say that such research is not valued. Clinical research to complement this research effort is urgently needed. Future research may well still need to focus on replacement posterior resin-type systems to produce direct posterior restorations with reduced polymerisation shrinkage, which
REFERENCES 1
2
48
Brunton PA. Effectively managing dental caries: prevention and disease ownership. Prim Dent J. 2013;2:26-9. Brunton PA, Davies RP, Burke JL, Smith A, Aggeli A, Brookes SJ, et al. Treatment of early caries lesions using biomimetic self-
3
4
is the major limitation of these materials. Pragmatically we must ask the question, will further reducing shrinkage change clinical outcomes? There may well be a new generation of materials emerging in the near future. Any new restorative system introduced, be it for the direct and/or indirect restoration of posterior teeth, would have to be rigorously researched and evaluated to test it against the current gold-standard resin composite and indirect material systems. As amalgam becomes used less and less for the restoration of posterior teeth, not for safety but for environmental reasons, future research needs to focus on the longevity of large posterior resin composite restorations. Some initial research has been performed showing the longevity of large resin composite restorations placed in posterior teeth by researchers in the Netherlands and further clinical trials should take place, ideally in dental practice, to test the efficacy of large resin composite restorations.3 Such research should be prioritised, in my view, to include patientcentred outcome measures. Studies tend to focus at the outcome at the tooth level and, although this is important, it is vital to involve patients in the outcome measures that we might develop. There also should be consensus or agreement as to what we actually mean by ‘longevity’ for restorations and what constitutes a failed restoration.
two patterns of care emerging for patients who might opt to have smaller interventions on a more regular basis (the so-called repair-focused patient) rather than to have larger interventions, possibly on a less frequent basis (the so-called replacementdriven patient). In doing this research, we must accept that patients have both choices and options that require evaluation. I think this is where research should focus in the future, involving patients in research looking at different patterns of care to include patient-centred outcome measures. In tandem with this, research priorities should be to look at pragmatic forms of randomised controlled trials, which have been described in medicine.6 Researching the use of possible proxy measures that allow us effectively to evaluate resin composites and new restorative systems in an effective way would also be helpful.
Research also needs to focus on repair versus replacement of restorations because recent Cochrane Reviews have suggested that there is very little evidence to show which is better in terms of outcomes for patients.4,5 In essence, there are potentially
assembling peptides: a clinical safety trial. Br Dent J. 2013;215:E6. Demarco FF, Corrêa MB, Cenci MS, Moraes RR, Opdam NJ. Longevity of posterior composite restorations: not only a matter of materials. Dent Mater. 2012;28:87-101. Sharif MO, Merry A, Catleugh M,
5
Tickle M, Brunton P, Dunne SM, et al. Replacement versus repair of defective restorations in adults: amalgam. Cochrane Database Syst Rev. 2014;2:CD005970. Sharif MO, Catleugh M, Merry A, Tickle M, Dunne SM, Brunton P, et al. Replacement versus repair of defective restorations in adults: resin composite. Cochrane
6
Database Syst Rev. 2014;2:CD005971. Porzsolt F, Eisemann M, Habs M, Wyer P. Form follows function: pragmatic controlled trials (PCTs) have to answer different questions and require different designs than randomized controlled trials (RCTs). Z Gesundh Wiss. 2013;21:307-13.
P R I M A R Y D E N TA L J O U R N A L
I
ncreasingly, we are seeing fewer indirect restorations being provided for patients, notably for the restoration of posterior teeth. In tandem with this, there has been a growing use of direct techniques to restore posterior teeth. This change, in my opinion, appears to be primarily due to improvements in oral health, coupled with a reduction in the need for and/or prescription of indirect restorations. This may be due to increased costs associated with the provision of direct restorations and/or the scheme by which dental practitioners are remunerated for the care that they provide. The factors that underpin these clinical decisions certainly merit further exploration. Hitherto research has largely focused on indirect restorations, the use of CAD/CAM technologies and novel ways of producing indirect restorations and materials for the production of direct restorations. This research has rightly been very material and technique focused, and it is important that newer systems are appropriately evaluated. Against this backdrop, research into the priorities of improving the outcomes of direct and indirect restorations placed in posterior teeth has, to a certain extent, been ignored; this, in my view, should be a focus for future research activity. Although clinical research is difficult to perform, it is essential if we are to improve the outcomes of the treatment that we provide for our patients. Increasingly and, arguably, for some time now, the presence of caries is no longer an absolute indication for operative intervention. We have, in my view, moved towards a system of disease management for patients, who often have disease that does not require operative intervention and where the ultimate goal of treatment is not the eradication of all dental caries, the so-called surgical model of care.1
V O L 3 N O 2 M AY 2 0 1 4
However, it seems that there continues to be confusion as to when intervention (ie operative management of dental caries) is required.1 I believe that research should focus more on assessing the activity of lesions, providing evidenced-based indications for when operative intervention is required. This would be very helpful to both practitioners and patients alike. Research needs to focus on monitoring the activity of lesions not only in terms of the progression of dental caries (ie monitor the situation) but also those that would indicate operative intervention.1 This is arguably the most important decision a practitioner can take given that this initial intervention starts the tooth on its restorative career, sometimes called the restorative cycle or staircase, which can lead to the loss of a tooth. This first decision is therefore crucial, one that frequently lacks clinical evidence to support it. Equally, practitioners are uncertain as to when indirect restorations should be replaced and/or, indeed, provided. Again, evidence-based authoritative guidelines would be helpful.
The management of dental caries at its early stages is currently a topical area for research and more needs to be carried out. The use of self-assembling peptides – a novel technology, recently described – is something that might be used during the early stages of dental caries, the socalled white spot lesion.2 Such technology needs to be rigorously evaluated to test for efficacy.
1
Paul A Brunton
Professor of Restorative Dentistry, University of Leeds
47
RESEARCH PRIORITIES FOR MANAGING THE RESTORATION OF POSTERIOR TEETH
In recent years much research has focused on dentine adhesive systems or dentinebonding agents, specifically for use with resin composite in the restoration of both anterior and posterior teeth. Many studies have looked at bond strengths and microleakage, and the hybrid layer has been studied in great detail. Going forward, I think research needs to focus on two areas: • Increasing the resistance of collagen within the hybrid layer to the enzymes active within dentine and cross-linking agents to improve the resistance of collagen to these enzymes. • The reduction in enzyme activity in tandem with initial research, which has proved interesting, that has looked at remineralisation of the hybrid layer. Further work needs to focus on this. We must not lose sight, however, of the need for clinically relevant research and the fact that a significant amount of research in this area has little clinical relevance, in my opinion. I am minded to think of the many posters, lectures and research papers that I have seen over the years at research meetings looking at newer materials and microleakage and investigating new dentine adhesive systems: I ask myself, what effect this has actually had on improving outcomes for patients? If I am honest, the answer is ‘very little’. This is not to say that such research is not valued. Clinical research to complement this research effort is urgently needed. Future research may well still need to focus on replacement posterior resin-type systems to produce direct posterior restorations with reduced polymerisation shrinkage, which
REFERENCES 1
2
48
Brunton PA. Effectively managing dental caries: prevention and disease ownership. Prim Dent J. 2013;2:26-9. Brunton PA, Davies RP, Burke JL, Smith A, Aggeli A, Brookes SJ, et al. Treatment of early caries lesions using biomimetic self-
3
4
is the major limitation of these materials. Pragmatically we must ask the question, will further reducing shrinkage change clinical outcomes? There may well be a new generation of materials emerging in the near future. Any new restorative system introduced, be it for the direct and/or indirect restoration of posterior teeth, would have to be rigorously researched and evaluated to test it against the current gold-standard resin composite and indirect material systems. As amalgam becomes used less and less for the restoration of posterior teeth, not for safety but for environmental reasons, future research needs to focus on the longevity of large posterior resin composite restorations. Some initial research has been performed showing the longevity of large resin composite restorations placed in posterior teeth by researchers in the Netherlands and further clinical trials should take place, ideally in dental practice, to test the efficacy of large resin composite restorations.3 Such research should be prioritised, in my view, to include patientcentred outcome measures. Studies tend to focus at the outcome at the tooth level and, although this is important, it is vital to involve patients in the outcome measures that we might develop. There also should be consensus or agreement as to what we actually mean by ‘longevity’ for restorations and what constitutes a failed restoration.
two patterns of care emerging for patients who might opt to have smaller interventions on a more regular basis (the so-called repair-focused patient) rather than to have larger interventions, possibly on a less frequent basis (the so-called replacementdriven patient). In doing this research, we must accept that patients have both choices and options that require evaluation. I think this is where research should focus in the future, involving patients in research looking at different patterns of care to include patient-centred outcome measures. In tandem with this, research priorities should be to look at pragmatic forms of randomised controlled trials, which have been described in medicine.6 Researching the use of possible proxy measures that allow us effectively to evaluate resin composites and new restorative systems in an effective way would also be helpful.
Research also needs to focus on repair versus replacement of restorations because recent Cochrane Reviews have suggested that there is very little evidence to show which is better in terms of outcomes for patients.4,5 In essence, there are potentially
assembling peptides: a clinical safety trial. Br Dent J. 2013;215:E6. Demarco FF, Corrêa MB, Cenci MS, Moraes RR, Opdam NJ. Longevity of posterior composite restorations: not only a matter of materials. Dent Mater. 2012;28:87-101. Sharif MO, Merry A, Catleugh M,
5
Tickle M, Brunton P, Dunne SM, et al. Replacement versus repair of defective restorations in adults: amalgam. Cochrane Database Syst Rev. 2014;2:CD005970. Sharif MO, Catleugh M, Merry A, Tickle M, Dunne SM, Brunton P, et al. Replacement versus repair of defective restorations in adults: resin composite. Cochrane
6
Database Syst Rev. 2014;2:CD005971. Porzsolt F, Eisemann M, Habs M, Wyer P. Form follows function: pragmatic controlled trials (PCTs) have to answer different questions and require different designs than randomized controlled trials (RCTs). Z Gesundh Wiss. 2013;21:307-13.
P R I M A R Y D E N TA L J O U R N A L
