A clinical guide to endodontics – update part 2

P. V. Carrotte1 and P. J. Waterhouse2 IN BRIEF • An overview of the recent changes relating to pulp therapy for children, particularly concerning the primary dentition. • Discusses the issues surrounding the use of formaldehyde in dentistry. • Discusses the clinical pulp therapy techniques which can be used for extensively carious primary teeth. • Highlights the growing evidence base that has provided an increased understanding of the healing capacity of the pulp. PRACTICE A clinical guide to endodontics – update part 2 This second update paper aims to provide a review of changes and developments that have occurred within the field of pulp therapy for primary teeth since the publication of the BDJ’s series and textbook A clinical guide to endodontics. The biological basis of pulp therapy is an area where much recent research has taken place, particularly linked to the healing capacity of pulp tissue. This has lead to the adoption of treatment techniques aimed at maintaining pulp vitality. Such techniques are introduced here as a more contemporary, biological approach to pulp management in the primary dentition. INTRODUCTION This is the second of two papers reviewing the changes and developments that have occurred in the four years since the BDJ’s textbook A clinical guide to endodontics was published. The fi rst part considered the materials and methods used in endodontic therapies for permanent teeth and discussed the considerable change in the practice of endodontic surgery. This second part focuses specifically on pulp therapy in children’s dentistry. PULP THERAPY FOR CHILDREN Permanent teeth Pulp therapy in paediatric dentistry may be required for both primary and permanent teeth. With regard to the latter, little has changed in treatment techniques since A clinical guide to endodontics was published. Several papers have been 1 Senior Clinical University Teacher and Associate Specialist in Endodontics, Unit of Adult Dental Care, Glasgow Dental Hospital and School, 378 Sauchiehall Street, Glasgow, G2 3JZ; 2*Clinical Senior Lecturer in Child Dental Health and Honorary Consultant in Paediatric Dentistry, The Newcastle University School of Dental Sciences, Framlington Place, Newcastle upon Tyne, NE2 4BW Correspondence to: Dr Paula J. Waterhouse Email: Refereed Paper Accepted 16 June 2008 DOI: 10.1038/sj.bdj.2009.56 © British Dental Journal 2009; 206: 133-139 published on the very successful outcomes when mineral trioxide aggregate (MTA) is used as a pulp capping agent in permanent teeth.1,2 There is an old endodontic cliché that the best root fi lling is a vital pulp – even more significant if vitality can be maintained in immature permanent teeth, allowing completion of root apex formation and root canal maturation. These reports may be considered together with the only other recent significant change regarding pulpal therapy of permanent teeth. In 2005, Bjorndal and Kidd 3 summarised the principles of current thinking in caries management, describing the ‘stepwise’ removal of caries with pulp capping. Research shows that when the cavity is subsequently revisited, in the vast majority of cases caries has arrested and/or remineralisation has taken place. This may reduce the need for subsequent root canal therapy. Endodontists have traditionally been reluctant to attempt such pulp capping techniques because anecdotally it was suggested that if treatment was not completely successful, a chronic low-grade inflammation resulted and the tooth developed what was termed ‘asymptomatic irreversible pulpitis’. As a result of this, sclerosis made eventual root canal treatment more difficult, thus reducing the likelihood of a good prognosis. However, in the light of this report 3 and a recent Cochrane BRITISH DENTAL JOURNAL VOLUME 206 NO. 3 FEB 14 2009 review concerning caries excavation,4 a knowledge, understanding and practice of modern methods of caries management and the associated scientific evidence is essential for comprehensive treatment of carious permanent teeth in children. Primary teeth While there may have been little change in the treatment of permanent teeth, there has been significant change in the approaches to vital and non-vital pulp therapy for the primary teeth. These can be divided into the following: Vital pulp therapy • Indirect pulp therapy (IPT) or indirect pulp capping • Direct pulp capping • Vital pulpotomy. Non-vital pulp therapy • Pulpectomy. Vital pulp therapy aims to treat reversible pulp injuries, maintain vitality and function and preserve the primary tooth until exfoliation. Non-vital pulp therapy involves the removal of irreversibly inflamed or necrotic pulp tissue, cleaning of the root canals and obturation with a resorbable paste and aims to restore and/or maintain the health of the periradicular tissues until tooth exfoliation. 133 © 2009 Macmillan Publishers Limited. All rights reserved. PRACTICE Indirect pulp therapy (IPT) Indirect pulp therapy is where a layer of discoloured carious dentine is purposely left at the floor of the cavity to prevent pulp exposure and additional trauma to the pulp. It follows the same principles as discussed previously for permanent teeth. This approach has been reported to be successful in symptom-free primary teeth with deep carious lesions when calcium hydroxide or glass ionomer lining cement was used as the indirect pulp capping material.5,6 Indeed, the fi ndings of Marchi et al.6 were significant, showing the same order of success when either calcium hydroxide or glass ionomer lining cement was used as the indirect pulp capping agent. It is worth noting that success of IPT is also thought to be dependent upon securing a leakage-free defi nitive restoration, such as a preformed metal crown or bonded restoration.7 Glass ionomer cement is not durable enough to be used as a defi nitive restoration. Once again, if pulp vitality can be maintained, the need for any root canal treatment will be avoided. Direct pulp capping Direct pulp capping in the primary dentition, where an agent is placed in direct contact with exposed pulp tissue, should be reserved for non-carious, iatrogenic exposures only. Favourable results were reported when MTA was used as the direct pulp capping agent.812 Such treatment must be carried out in aseptic conditions, preferably under rubber dam, to enhance the chance of success. In addition, previous studies have reported similar levels of success when calcium hydroxide was used in these situations.5,6 Single-visit vital pulpotomy The gold standard agent in vital primary molar pulpotomy procedures since the 1930s has been Buckley’s formocresol solution (BFS), either in its full strength solution or a 20% (1:5) dilution.13 At the time A clinical guide to endodontics was being published, several papers were appearing in the dental literature questioning the use of this traditional pulpotomy medicament. Questions have been raised concerning the safety of BFS, in part due (...truncated)