The Dahl Concept: past, present and future

Abstract

The Dahl appliance was described nearly 30 years ago. This removable metal bite platform was used to create inter-occlusal space, in a localised part of the mouth, to facilitate the placement of restorations on worn anterior teeth. The Dahl concept is traditionally associated with the management of worn teeth. However, the same principles can be successfully and safely applied to a variety of clinical situations. This has simplified the management of historically complex problems. The advantages are the preservation of tooth tissue and the long-term benefits that brings. This paper reviews the literature related to the Dahl concept and how the concept has developed. There is a discussion regarding possible future applications and research.

Dental appliances with inadequate occlusal coverage: a case report

“…9,11 Nevertheless, this propensity for adult teeth to erupt when taken out of occlusion is used to good advantage when worn anterior teeth that require space recreation before restoration are initially managed with a Dahl appliance. 12 …”

Current concepts on the management of tooth wear: part 2. Active restorative care 1: the management of localised tooth wear

“…10 A very successful short term prognosis has been described for the use of direct composite resin when placed in supraocclusion, utilising the Dahl approach to restore the presence of a worn lower anterior dentition. 11 In the latter study the vertical occlusal dimensions of the cases included were increased in the range of 0.5 to 5.0 mm.…”

“…Other phrases used to describe the latter concept include 'minor axial tooth movement', 'fixed orthodontic intrusion', 'localised inter-occlusal space creation' or 'relative axial tooth movement' . 11 The same principle may be extended to the controlled movement of posterior teeth to create space.…”

“…According to a review by Poyser et al, 11 when considering studies which have assessed the efficacy of the Dahl concept, a success rate of between 94-100% has been reported. Furthermore, the level of space creation was consistently found to be irrespective of age and sex.…”

“…While there is little evidence in literature to suggest that the process of controlled intrusion and extrusion is associated with possible adverse effects such as pulpal symptoms, periodontal problems, TMJ dysfunction symptoms and apical root resorption, 11 compliance with removable appliances has been identified as a concern. 10 To overcome the issues related to patient compliance and aesthetic concerns of the removable prosthesis, Ibbetson and Setchell 13 have described an alternative approach involving the provision of a fixed metal prosthesis which was cemented in supra-occlusion with the same occlusal prescription as with the removable appliance, with a glass ionomer lute or dual affinity cement.…”