Tooth wear is a significant challenge in modern dental care. Attrition, erosion, abrasion and abfraction are all described as sources of tooth wear, and the prevalence of the problem only increases with patient age.[i] The level of erosion in the permanent dentition of children, adolescents, and adults alike could be as high as 88%.[ii]
It is an issue faced on a regular basis, and dental professionals must be equipped with suitable treatment techniques that provide restorations before the condition of the dentition falls into further disarray.
Early, non-invasive intervention will always be preferred over full mouth rehabilitation. And so, in select cases, the Dahl principle may be of use. Understanding how to implement it with modern dental solutions, and more importantly when it can be effective, allows dental professionals to add another string to their clinical bow; anterior tooth wear could well be prevented and managed effectively, for years to come.
Understanding the Dahl principle
The Dahl concept consists of the relative axial tooth movement that is observed through the use of a localised appliance/restoration that is placed in supra-occlusion, allowing the occlusion to re-establish full arch contacts over time.[iii]
When implemented in a timely manner, patients can receive additive restorations to their anterior teeth, which can restore aesthetics and reduce/prevent common physiological side effects that result in a reduced quality of life – these include sensitivity, pain and headaches.[iv] Today, these additive restorations are most often direct composite solutions that create taller anterior incisors, with a smooth and aesthetic finish. Previously, a supra-occlusal appliance would have permanently disrupted the bite, allowing the unaffected teeth to erupt and restore occlusion.
The Dahl concept is recognised as a highly successful solution in dentistry, research has shown that objectives are reached in 94%-100% of cases.iii These objectives would be to either create inter-occlusal space so that restorations can be placed, or re-establish occlusal contacts after the placement of restorations.
Appropriate case selection
As with any treatment, the Dahl concept can only be successful with appropriate case-selection. When treating localised anterior wear, it is ideal to perform the Dahl concept before the posterior teeth experience wear too. Once both the anterior and posterior regions have been damaged, a patient would be better suited to full arch treatment – a Dahl approach would only restore select parts of the dentition, leaving the posterior teeth in occlusion but with wear still present.
Clinicians must understand that the Dahl approach will affect the inter-occlusal space, and therefore it is of no use if the treatment planning lacks a proper diagnosis and calculation of the space required.[v] The thickness of an appliance or restoration will define the increase in vertical dimension of the occlusion. Previous studies have found that an increase between 1.8mm to 4.7mm is possible,iii and it is, of course, important for dental professionals to remain realistic with what can be achieved. A lack of eruptive potential has been described as a cause of treatment failure, meaning occlusion is not restored throughout the dentition, but this is rare.iii
Patient compliance was previously thought to be a significant risk for treatment failure.iii Where a removable appliance was implemented, patients needed to use it regularly and for extensive periods of time to encourage the posterior teeth to erupt – of course, if this was not diligently followed, progress would not be made. Fixed appliances and directly placed composite restorations eliminate this concern, and compliance is only needed to maintain oral hygiene – the rest is a waiting game.
Learning the ropes
The Dahl principle cannot be implemented into everyday care without adequate professional training and an understanding of the approach, including how it can affect the occlusion and how this is restored. It should also be considered as an effective orthodontic approach that can be part of larger treatment plans for patients who want to transform their smiles and address anterior tooth wear.
Clinicians must seek out reliable and effective courses to be able to introduce the Dahl principles into their care. The Align, Bleach and Bond course from the IAS Academy provides exactly this, and arms clinicians with a range of insights on orthodontic and ortho-restorative care. The Dahl principle is taught in depth, exploring the science, the evidence, and hands-on application for immediate use in your practice. Leading tutors also provide insights on the use of clear aligner orthodontics, from diagnosis to case completion, and restorative techniques such as edge bonding and polishing.
In modern dentistry, anterior tooth wear is an issue that will be observed nearly every day. By intercepting its progression early with a minimally invasive approach, such as the Dahl principle, patients can receive exceptional care that restores aesthetics and function for years to come.
For more information on upcoming IAS Academy training courses, please visit www.iasortho.com or call 01932 336470 (Press 1)
Author: Dr Tif Qureshi, IAS Academy Founder and Clinical Director
Dr Tif Qureshi founder and a clinical director of IAS Academy, qualified from Kings College London in 1992. He is a Past President of the British Academy of Cosmetic Dentistry, an International faculty that provides mentored education for general dentists on a pathway from appropriate simple to comprehensive orthodontics.
Tif has a special interest in simple orthodontics and truly minimally invasive dentistry. He has committed his life’s work to empowering dentists to provide important alternative techniques. He offers a wide variety of treatments to many more patients, while always respecting the fundamental precepts of orthodontics.
Tif also pioneered the concept of Progressive Smile Design through Alignment, Bleaching, Bonding – a course that combines tooth alignment, composite bonding and teeth whitening to produce superior smiles using techniques with the absolute minimum of invasiveness available today.
An experienced teacher in the Dahl concept, Tif shows how this technique is used to plan tooth alignment and minimise invasive dentistry in the development of a beautiful smile.
Tif now lectures and published scientific articles internationally. BACK TO TEAM
[i] Hemmings, K., Truman, A., Shah, S., & Chauhan, R. (2018). Tooth wear guidelines for the bsrd part 1: aetiology, diagnosis and prevention. Dental Update, 45(6), 483-495.
[ii] Al-Seelawi, Z., Hermann, N. V., Peutzfeldt, A., Baram, S., Bakke, M., Sonnesen, L., … & Benetti, A. R. (2024). Clinical and digital assessment of tooth wear. Scientific Reports, 14(1), 592.
[iii] Poyser, N. J., Porter, R. W. J., Briggs, P. F. A., Chana, H. S., & Kelleher, M. G. D. (2005). The Dahl Concept: past, present and future. British Dental Journal, 198(11), 669-676.
[iv] Kumar, V., Reddy, S., Basha, R., & Mitra, N. (2023). Restorative Rehabilitation of a Patient With Tooth Wear: A One-Year Clinical Follow-Up Report. Cureus, 15(4).
[v] Mortada, H. H., (2022). Dahl approach and its applications in dentistry: a systematic review. IOSR Journal Of Pharmacy And Biological Sciences. 17(1)(Online) Available at: https://iosrjournals.org/iosr-jpbs/papers/Vol17-issue1/Ser-4/B1701041115.pdf
