What is the clinical evidence on approaches to caries removal?

This summary is based on the Critical Appraisal published in the Journal of Esthetic and Restorative Dentistry: Approaches to caries removal: what the clinical evidence says (April 2013)

Context 

It is very common that complete caries removal in vital, asymptomatic teeth with deep carious lesions ends in unavoidable exposure of the pulp. As a result, the complexity and cost of treatment increases dramatically and many patients are left with extraction as their only viable option.The review appraises evidence which supports alternative treatments designed to preserve the vitality of the tooth and thus avoid extraction.

Studies Reviewed

• Evaluation of Atraumatic Restorative Treatment and Sealants under Field Conditions. South African Dental Journal 2001 (56:309–15)
• Changes in the Cultivable Flora in Deep Carious Lesions following a Stepwise Excavation Procedure. Caries Research 2000 (34:502–8)
• Ultraconservative and Cariostatic Sealed Restorations: Results at Year 10. Journal of the American Dental Association 1998 (129:55–66)
• Complete or Ultraconservative Removal of Decayed Tissue in Unfilled Teeth (Review). Cochrane Database of Systematic Reviews 2006, Issue 3. Art. No.: CD003808.DOI: 10.1002/14651858.CD003808.pub2

Key Messages

• The profession’s present consensus that all caries must be removed, even at the risk of exposing the pulp, is based on the careful observations of G.V. Black made in conjunction with treatment of his patients. Although G.V. Black remains a giant in the dental profession, it is important to recall that things have changed over the years. Because G.V. Black’s observations were made, the profession has developed materials that allow us to seal restorations against microleakage on a consistent basis.
• The use of Atraumatic Restorative Treatment (ART) restorations demonstrates the enormity of the underlying clinical problem. Is there a different approach to the management of carious lesions which can preserve teeth rather than condemn them unnecessarily to extraction? Such an approach would represent a tremendous public health benefit.
• Although the early studies of ART were not scientifically rigorous, they provided evidence that a different approach might be available and that this approach was worthy of additional study. At this point, there is good, high-level evidence available supporting the partial excavation of caries as a means to avoid pulp exposure.
• Bjørndal and Larsen and other similar studies provide us with a physiological explanation of how partial caries excavation can be successful.
• The Mertz-Fairhurst and colleagues study did not use calcium hydroxide and achieved the same result, arrest of the carious lesion, as the Bjørndal and Larsen study.The evidence supports the conclusion that the use of calcium hydroxide is not a necessary step in arresting the progression of caries.
• The Mertz-Fairhurst and colleagues study supports the conclusion that sealing lesions from the nutrients found in the oral cavity is sufficient to arrest decay. Further, the study supports the conclusion that sealing the remaining pit and fissure system reduces the incidence of new decay.
• The evidence supports the use of occlusal sealants without concern for inadvertently sealing a tooth that has incipient caries. Accordingly, the use of procedures to investigate the pit and fissure system to determine whether caries is present, as opposed to using it as means to increase sealant retention, are not necessary and result in unnecessary loss of tooth structure.
• The evidence supports leaving all caries as a viable approach. From a public health standpoint, this could save considerable time and money. However, it is important to recall that restorations in the Mertz-Fairhurst and colleagues study had significantly greater longevity when all caries were removed than when no caries were removed. Thus, any benefits from not removing caries may represent a short-term but not a long-term or overall benefit.To our knowledge, no studies exist to answer this question.
• The Ricketts and colleagues review indicates that the risk of exposure increases nearly three-fold when a one-visit, remove-all-caries approach is used instead of a stepwise caries removal approach.
• When the pulp was not exposed, there was a low rate of pulpal inflammation and necrosis. This was the result regardless of the approach used, complete or partial caries removal. Thus, the key to success is to avoid pulp exposure.
• These studies support the conclusions that:
  • The use of partial caries excavation in order to avoid pulpal involvement leads to better outcomes in terms of inflammation or necrosis of the pulp.
  • Remaining caries does not progress.
  • Annual failure rates for teeth in which caries remained were reasonable (1.4%).
  • The public health implication of preserving teeth that would otherwise be extracted is tremendous, as is the benefit for the individual patient.

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