NIHR Signal “Shallow” treatments of adjacent teeth and their surfaces might be effective in slowing tooth decay

Published on 23 February 2016

This review found that new surface and shallow dental procedures, called micro-invasive treatments, reduce tooth decay by about three quarters. The treatments for adults were applied to the surfaces of teeth that touch or are next to each other. Four types of treatment were compared with non-invasive strategies such as advice on flossing or the application of fluoride varnish. There were too few trials to determine which micro-invasive technique is best, or for which groups of patients it was most suitable. This may limit the implementation of this promising approach into UK practice.

“Shallow” treatments of adjacent teeth and their surfaces might be effective in slowing tooth decay

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Why was this study needed?

Dental caries (tooth decay) represents an important preventable disease. Dental programmes for prevention are well developed in Scotland; where despite a steady improvement since the 1980s, more than a quarter of children overall have obvious decay. The greatest burden occurs in those from disadvantaged backgrounds. While oral health in England has improved significantly across the population too, marked inequalities do persist here also. In the 30 years up to 2009 one report shows that the proportion of adults in England without any natural teeth fell from 28% to 6%. However, people from managerial and professional occupation households had better oral health (91%) compared with people from routine and manual occupation households (79%).

Decay on adjacent tooth surfaces is common and is prevented by flossing. It is important to manage the early stages of decay before a cavity is formed and two methods are currently used. The first one is invasive and involves drilling and inserting a filling. The second method involves non-invasive strategies such as flossing or application of a fluoride varnish.

This systematic review aimed to examine a third approach using micro-invasive treatments. These treatments involve preparing the tooth surface using an acid and then applying a sealant or resin to protect the teeth from further decay. The researchers looked to see if these treatments might reduce the loss of dental hard tissue and the need for more invasive treatments in the future.

What did this study do?

This was a Cochrane systematic review that identified eight randomised controlled trials from Europe, Asia and South America including 365 children and adults. None were from the UK. All trials involved trying out the treatments on different teeth in the same person. All studies compared micro-invasive treatments to a range of non-invasive strategies such as dental hygiene advice on flossing or fluoride varnish in adults. Follow up ranged from one to three years. In seven of the eight trials the participants and the dental personnel were aware of the treatments that were used. These trials were assessed to be of high risk of bias. Four trials had received industry funding to conduct the research. The review followed standard systematic review methods and included a meta-analysis to pool the data from individual trials.

What did it find?

The researchers found seven trials and included 602 teeth in the analysis. They pooled data on the most sensitive measure of caries progression.

  • Micro-invasive treatment significantly reduced the odds of caries progression by 76% compared with non-invasive strategies or no treatment (odds ratio 0.24, 95% confidence interval 0.14 to 0.41).
  • No adverse events after the micro-invasive treatment were identified by the four studies that measured adverse outcomes.
  • It was not possible to establish which micro-invasive method worked better than the others due to the small number of trials.

What does current guidance say on this issue?

The 2014 guidelines of the Scottish Intercollegiate Guidelines Network on dental interventions to prevent caries in children did not include recommendations about any micro-invasive interventions. It does recommend fluoride varnish applied at least twice yearly in all children and the use of resin based sealants to permanent teeth.

NICE guidance on oral health for local authorities and partners published in 2014 suggests that amongst other things, an oral health needs assessment in performed and a strategy developed. This they say should set out how the local authority and its health and wellbeing commissioning partners will address the oral health needs of the local population as a whole and those groups at high risk of poor oral health. Minimally invasive procedure might be part of this strategy.

What are the implications?

The researchers acknowledge that although the overall treatment effect in these trials was large the quality of evidence was moderate. This was partly because the studies were of short duration. There was also a lack of blinding – staff carrying out procedures and measuring impact would have known which treatment was given. But objective measurements such as X-rays were used, so potential bias of this sort would not have made a large difference to the results. There was insufficient evidence to determine the benefits of different micro-invasive techniques. The size of this problem in the UK is large and so further testing of these micro-invasive treatments is likely in UK practice. For now it is not known if and how this new intervention will be taken up by dentists or other dental professionals. Training in its use will need to be considered.

Citation and Funding

Dorri M, Dunne SM, Walsh T, et al. Micro-invasive interventions for managing proximal dental decay in primary and permanent teeth. Cochrane Database Syst Rev. 2015;(11):CD010431.

No funding information was provided for this study.

Bibliography

SIGN. Dental interventions to prevent caries in children: a national clinical guideline. Edinburgh: Scottish Intercollegiate Guidelines Network; 2014.

NICE. Oral health: local authorities and partners [PH55]; 2014.

Why was this study needed?

Dental caries (tooth decay) represents an important preventable disease. Dental programmes for prevention are well developed in Scotland; where despite a steady improvement since the 1980s, more than a quarter of children overall have obvious decay. The greatest burden occurs in those from disadvantaged backgrounds. While oral health in England has improved significantly across the population too, marked inequalities do persist here also. In the 30 years up to 2009 one report shows that the proportion of adults in England without any natural teeth fell from 28% to 6%. However, people from managerial and professional occupation households had better oral health (91%) compared with people from routine and manual occupation households (79%).

Decay on adjacent tooth surfaces is common and is prevented by flossing. It is important to manage the early stages of decay before a cavity is formed and two methods are currently used. The first one is invasive and involves drilling and inserting a filling. The second method involves non-invasive strategies such as flossing or application of a fluoride varnish.

This systematic review aimed to examine a third approach using micro-invasive treatments. These treatments involve preparing the tooth surface using an acid and then applying a sealant or resin to protect the teeth from further decay. The researchers looked to see if these treatments might reduce the loss of dental hard tissue and the need for more invasive treatments in the future.

What did this study do?

This was a Cochrane systematic review that identified eight randomised controlled trials from Europe, Asia and South America including 365 children and adults. None were from the UK. All trials involved trying out the treatments on different teeth in the same person. All studies compared micro-invasive treatments to a range of non-invasive strategies such as dental hygiene advice on flossing or fluoride varnish in adults. Follow up ranged from one to three years. In seven of the eight trials the participants and the dental personnel were aware of the treatments that were used. These trials were assessed to be of high risk of bias. Four trials had received industry funding to conduct the research. The review followed standard systematic review methods and included a meta-analysis to pool the data from individual trials.

What did it find?

The researchers found seven trials and included 602 teeth in the analysis. They pooled data on the most sensitive measure of caries progression.

  • Micro-invasive treatment significantly reduced the odds of caries progression by 76% compared with non-invasive strategies or no treatment (odds ratio 0.24, 95% confidence interval 0.14 to 0.41).
  • No adverse events after the micro-invasive treatment were identified by the four studies that measured adverse outcomes.
  • It was not possible to establish which micro-invasive method worked better than the others due to the small number of trials.

What does current guidance say on this issue?

The 2014 guidelines of the Scottish Intercollegiate Guidelines Network on dental interventions to prevent caries in children did not include recommendations about any micro-invasive interventions. It does recommend fluoride varnish applied at least twice yearly in all children and the use of resin based sealants to permanent teeth.

NICE guidance on oral health for local authorities and partners published in 2014 suggests that amongst other things, an oral health needs assessment in performed and a strategy developed. This they say should set out how the local authority and its health and wellbeing commissioning partners will address the oral health needs of the local population as a whole and those groups at high risk of poor oral health. Minimally invasive procedure might be part of this strategy.

What are the implications?

The researchers acknowledge that although the overall treatment effect in these trials was large the quality of evidence was moderate. This was partly because the studies were of short duration. There was also a lack of blinding – staff carrying out procedures and measuring impact would have known which treatment was given. But objective measurements such as X-rays were used, so potential bias of this sort would not have made a large difference to the results. There was insufficient evidence to determine the benefits of different micro-invasive techniques. The size of this problem in the UK is large and so further testing of these micro-invasive treatments is likely in UK practice. For now it is not known if and how this new intervention will be taken up by dentists or other dental professionals. Training in its use will need to be considered.

Citation and Funding

Dorri M, Dunne SM, Walsh T, et al. Micro-invasive interventions for managing proximal dental decay in primary and permanent teeth. Cochrane Database Syst Rev. 2015;(11):CD010431.

No funding information was provided for this study.

Bibliography

SIGN. Dental interventions to prevent caries in children: a national clinical guideline. Edinburgh: Scottish Intercollegiate Guidelines Network; 2014.

NICE. Oral health: local authorities and partners [PH55]; 2014.

Micro-invasive interventions for managing proximal dental decay in primary and permanent teeth

Published on 7 November 2015

Dorri, M.,Dunne, S. M.,Walsh, T.,Schwendicke, F.

Cochrane Database Syst Rev Volume 11 , 2015

BACKGROUND: Proximal dental lesions, limited to dentine, are traditionally treated by invasive (drill and fill) means. Non-invasive alternatives (e.g. fluoride varnish, flossing) might avoid substance loss but their effectiveness depends on patients' adherence. Recently, micro-invasive approaches for treating proximal caries lesions have been tried. These interventions install a barrier either on top (sealing) or within (infiltrating) the lesion. Different methods and materials are currently available for micro-invasive treatments, such as sealing via resin sealants, (polyurethane) patches/tapes, glass ionomer cements (GIC) or resin infiltration. OBJECTIVES: To evaluate the effects of micro-invasive treatments for managing proximal caries lesions in primary and permanent dentition in children and adults. SEARCH METHODS: We searched the following databases to 31 December 2014: the Cochrane Oral Health Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE via OVID, EMBASE via OVID, LILACs via BIREME Virtual Health Library, Web of Science Conference Proceedings, ZETOC Conference Proceedings, Proquest Dissertations and Theses, ClinicalTrials.gov, OpenGrey and the World Health Organization (WHO) International Clinical Trials Registry Platform. We searched the metaRegister of Controlled Trials to 1 October 2014. There were no language or date restrictions in the searches of the electronic databases. SELECTION CRITERIA: We included randomised controlled trials of at least six months' duration that compared micro-invasive treatments for managing non-cavitated proximal dental decay in primary teeth, permanent teeth or both, versus non-invasive measures, invasive means, no intervention or placebo. We also included studies that compared different types of micro-invasive treatments. DATA COLLECTION AND ANALYSIS: Two review authors independently screened search results, extracted data and assessed the risk of bias. We used standard methodological procedures expected by Cochrane to evaluate risk of bias and synthesise data. We conducted meta-analyses with the random-effects model, using the Becker-Balagtas method to calculate the odds ratio (OR) for lesion progression. We assessed the quality of the evidence using GRADE methods. MAIN RESULTS: We included eight trials, which randomised 365 participants. The trials all used a split-mouth design, some with more than one pair of lesions treated within the same participant. Studies took place in university or dental public health clinics in Brazil, Colombia, Denmark, Germany, Thailand, Greenland and Chile. Six studies evaluated the effects of micro-invasive treatments in the permanent dentition and two studies on the primary dentition, with caries risk ranging from low to high. Investigators measured caries risk in different studies either by caries experience alone or by using the Cariogram programme, which combines eight contributing factors, including caries experience, diet, saliva and other factors related to caries. The follow-up period in the trials ranged from one to three years. All studies used lesion progression as the primary outcome, evaluating it by different methods of reading radiographs. Four studies received industry support to carry out the research, with one of them being carried out by inventors of the intervention.We judged seven studies to be at high overall risk of bias, primarily due to lack of blinding of participants and personnel. We evaluated intervention effects for all micro-invasive therapies and analysed subgroups according to the different treatment methods reported in the included studies.Our meta-analysis, which pooled the most sensitive set of data (in terms of measurement method) from studies presenting data in a format suitable for meta-analysis, showed that micro-invasive treatment significantly reduced the odds of lesion progression compared with non-invasive treatment (e.g fluoride varnish) or oral hygiene advice (e.g to floss) (OR 0.24, 95% CI 0.14 to 0.41; 602 lesions; seven studies; I2 = 32%). There was no evidence of subgroup differences (P = 0.36).The four studies that measured adverse events reported no adverse events after micro-invasive treatment. Most studies did not report on any further outcomes.We assessed the quality of evidence for micro-invasive treatments as moderate. It remains unclear which micro-invasive treatment is more advantageous, or if certain clinical conditions or patient characteristics are better suited for micro-invasive treatments than others. AUTHORS' CONCLUSIONS: The available evidence shows that micro-invasive treatment of proximal caries lesions arrests non-cavitated enamel and initial dentinal lesions (limited to outer third of dentine, based on radiograph) and is significantly more effective than non-invasive professional treatment (e.g. fluoride varnish) or advice (e.g. to floss). We can be moderately confident that further research is unlikely to substantially change the estimate of effect. Due to the small number of studies, it does remain unclear which micro-invasive technique offers the greatest benefit, or whether the effects of micro-invasive treatment confer greater or lesser benefit according to different clinical or patient considerations.

The micro-invasive treatment  involve preparing the tooth surface with an acid and then either placing a sealing cover on top of the surface or ’infiltrating’ the softer demineralised tissue with resins. These newer methods work by installing a barrier either on the tooth surface or within the softer tissue to protect it against acids and avoid the further loss of minerals from within the tooth. This, in theory, should stop the decay.

This approach can be performed by a dentist or other dental practitioner and involves the loss of a few micrometres of tooth tissue because of the need to condition the tooth surface with acid.

The treatments studied in this review covered a variety of different substances and techniques. These included the use of different strengths of acid for removing the affected area of the tooth. This area was then treated with resin infiltration, resin sealant, sealant patch or glass ionomer.

Expert commentary

Advances in dental materials, changed philosophies on how to treat decayed teeth and increased understanding of the dental caries process, particularly when in its early stages before the tooth structure breaks down to form a cavity, have had a marked influence on how decaying teeth are managed and restored. This systematic review looks at the latest advance, namely that of micro-invasive techniques being used to halt decay progression on proximal tooth surfaces (i.e. the surfaces between the teeth which are particularly prone to decay).  These techniques are still at an early stage of adoption in general dentistry in the UK but this work suggests that they have potential clinical benefit.

Professor Ivor G. Chestnutt, Professor and Honorary Consultant in Dental Public Health, Associate Dean Postgraduate Studies, Cardiff University Dental School