Wear and tear are significant components for a product’s life expectancy, and teeth are no different. In 2021, the last UK survey of dentate adults found that 2% had severe tooth wear, 15% had moderate wear, and 77% had some wear present.[i] It is an ever-present problem, with the anterior teeth most effected by a range of aetiological factors, from mechanical to chemical processes. Tooth wear can have considerable impact on a patient’s quality of life, leading to:
Pain and discomfort-Functional issues-Decline in aesthetics-Treatment complications [ii]
To treat tooth wear, practitioners can offer dental crowns, veneers and dental bonding, depending on the needs of the patient. For a more conservative method of treating worn anterior teeth, the Dahl principle should be considered. However, the wider dental profession is often cautious or unfamiliar in its use;[iii] it is an alternative way of approaching tooth wear with little online documentation.[iv] For dental practitioners looking to treat tooth wear in a less invasive way, understanding the Dahl principle can lead to improved outcomes and greater patient satisfaction.
Defining the Dahl principle
Named after the dentist who pioneered it in 1975, the Dahl principle uses a metal bite platform to create inter occlusal space through axial tooth movement. Dahl sought to create space between the posterior and anterior teeth to more ably treat the localised anterior wear – the process takes several months.[v] This facilitates the placement of restorations on worn teeth without having to treat the molar teeth.[vi] Passive eruption will close the residual spaces in the months afterwards.[vii] The Dahl principle is a predictable treatment style that involves tooth intrusion, tooth extrusion and mandibular distalisation, but it cannot be used without considering:
- Patient age
- Occlusal adaptability
- Skeletal and incisal pattern
- Temporomandibular joint disorder (TMD) history
- Parafunctional habits
- Altered bone metabolism[viii]
More local considerations include if the patient has retainers or splints, if there are any implants or fixed prostheses, and their periodontal status.[ix]
A modern solution
Where Dahl originally introduced a removable appliance made of cobalt chromium, practitioners of today can achieve the same outcome with a less invasive alternative: direct adhesive anterior composite.[x] As the success of a removable Dahl appliance is dependent on the patient’s cooperation, using an adhesive composite increases comfort and compliance, leading to a favourable outcome.[xi] Moreover, the Dahl principle is reversible and safe, with limited destruction of the enamel or dentine.[xii] Without the Dahl principle, practitioners would have to reduce the occlusal height of the impacted teeth further, a process which can risk damage to the tooth pulp.[xiii]
This, as well as the low invasiveness, can make a Dahl appliance a more appealing option for patients with dental anxiety because of its low risk.
The results from patients who have been treated with the Dahl principle have shown long-lasting benefits, with all participants showing evidence of teeth movement, regardless of age,[xiv] and 94% of treated patients reporting no new TMD symptoms.[xv] The risk of root resorption is also extremely low when comparing a Dahl appliance to other orthodontic options.[xvi] Providing that the initial diagnosis, treatment planning, and estimation of inter occlusal space are correct, a Dahl appliance is a reliable and repeatable approach, with minimal complications. It is also low in cost – many treatments for tooth wear are expensive, meaning patients may struggle finding a suitable solution and the tooth wear will go untreated.[xvii] The Dahl approach can reduce costs without compromising on aesthetic or functional outcomes as, when combined with alignment and whitening, it produces excellent and non-invasive results.[xviii]
Learn more, treat more
To dive deeper into the Dahl principle and build on your skills and knowledge in occlusion, sign up for the Ortho Restorative (Level 2) course from the IAS Academy. An exciting follow-up to the popular and impactful Align, Bleach and Bond course, Dr Tif Qureshi and Dr Shiraz Khan are back with a comprehensive two-day fusion of theory and hands-on learning. This includes an advanced insight into the Dahl principle and Dahl retainer build-ups, allowing you to truly understand and conduct the Dahl principle on appropriate patients for reliable treatment outcomes.
Tooth wear will continue to present among patients of all ages and, if left unchecked, it can be detrimental to their quality of life. By exploring new avenues to combat wear, practitioners can provide more treatment options, with the Dahl principle representing a cost-effective and reliable solution for the patients who need their smile back.
For more information on upcoming IAS Academy training courses, please visit www.iasortho.com or call 01932 336470 (Press 1)
[i] GOV.UK. (2021). Chapter 7: Tooth wear. [online] Available at: https://www.gov.uk/government/publications/delivering-better-oral-health-an-evidence-based-toolkit-for-prevention/chapter-7-tooth-wear.
[ii] Rezaei, M., Chalakinia, H., Mohammadi, M.D. and Khosravi, F. (2023). Conservative and cost‐effective rehabilitation of a deep bite patient with worn dentition: A case report of the Dahl technique approach. Clinical Case Reports, 11(10). doi:https://doi.org/10.1002/ccr3.8058.
[iii] Ray-Chaudhuri, A., Brown, T., Ray-Chaudhuri, E., Critchlow, S., Dubal, R., Gadhia, K. and Tabiat-Pour, S. (2023). When (and when not) to use the Dahl Concept. British Dental Journal, 234(3), pp.155–164. doi:https://doi.org/10.1038/s41415-023-5502-9.
[iv] Qureshi , T. (n.d.). The Dahl principle in everyday dentistry . [online] Available at: https://www.inmanaligner.com/media/pdf/PD%20Oct%20tif.pdf [Accessed 3 Jan. 2025].
[v] Qureshi , T. (n.d.). The Dahl principle in everyday dentistry . [online] Available at: https://www.inmanaligner.com/media/pdf/PD%20Oct%20tif.pdf [Accessed 3 Jan. 2025].
[vi] Poyser, N.J., Porter, R.W.J., Briggs, P.F.A., Chana, H.S. and Kelleher, M.G.D. (2005). The Dahl Concept: past, present and future. British Dental Journal, [online] 198(11), pp.669–676. doi:https://doi.org/10.1038/sj.bdj.4812371.
[vii] Qureshi , T. (n.d.). The Dahl principle in everyday dentistry . [online] Available at: https://www.inmanaligner.com/media/pdf/PD%20Oct%20tif.pdf [Accessed 3 Jan. 2025].
[viii] Ray-Chaudhuri, A., Brown, T., Ray-Chaudhuri, E., Critchlow, S., Dubal, R., Gadhia, K. and Tabiat-Pour, S. (2023). When (and when not) to use the Dahl Concept. British Dental Journal, 234(3), pp.155–164. doi:https://doi.org/10.1038/s41415-023-5502-9.
[ix] Ray-Chaudhuri, A., Brown, T., Ray-Chaudhuri, E., Critchlow, S., Dubal, R., Gadhia, K. and Tabiat-Pour, S. (2023). When (and when not) to use the Dahl Concept. British Dental Journal, 234(3), pp.155–164. doi:https://doi.org/10.1038/s41415-023-5502-9.
[x] Qureshi , T. (n.d.). The Dahl principle in everyday dentistry . [online] Available at: https://www.inmanaligner.com/media/pdf/PD%20Oct%20tif.pdf [Accessed 3 Jan. 2025].
[xi] Rezaei, M., Chalakinia, H., Mohammadi, M.D. and Khosravi, F. (2023). Conservative and cost‐effective rehabilitation of a deep bite patient with worn dentition: A case report of the Dahl technique approach. Clinical Case Reports, 11(10). doi:https://doi.org/10.1002/ccr3.8058.
[xii] Anon, (2021). The Dahl Concept – Windsor Advanced Dentistry. [online] Available at: https://www.advanceddentistry.co.uk/blog/the-dahl-concept/.
[xiii] Anon, (2021). The Dahl Concept – Windsor Advanced Dentistry. [online] Available at: https://www.advanceddentistry.co.uk/blog/the-dahl-concept/.
[xiv] Bhai, K., Judge, R., Jaafar Abduo and Palamara, J. (2023). Measuring tooth movement with treatment using the Dahl principle: An observational study. The journal of prosthetic dentistry/The Journal of prosthetic dentistry, 129(4), pp.554–560. doi:https://doi.org/10.1016/j.prosdent.2021.07.010.
[xv] Poyser, N.J., Porter, R.W.J., Briggs, P.F.A., Chana, H.S. and Kelleher, M.G.D. (2005). The Dahl Concept: past, present and future. British Dental Journal, [online] 198(11), pp.669–676. doi:https://doi.org/10.1038/sj.bdj.4812371.
[xvi] Mortada, H. (2022). Dahl approach and its applications in dentistry: a systematic review. IOSR Journal Of Pharmacy And Biological Sciences (IOSR-JPBS) e, [online] 17, pp.11–15. doi:https://doi.org/10.9790/3008-1701041115.
[xvii] Qureshi , T. (n.d.). The Dahl principle in everyday dentistry . [online] Available at: https://www.inmanaligner.com/media/pdf/PD%20Oct%20tif.pdf [Accessed 3 Jan. 2025].
[xviii] Qureshi , T. (n.d.). The Dahl principle in everyday dentistry . [online] Available at: https://www.inmanaligner.com/media/pdf/PD%20Oct%20tif.pdf [Accessed 3 Jan. 2025].
