The Hall Technique is a minimally-invasive treatment for decayed baby back (molar) teeth. Decay is sealed under preformed (stainless steel) crowns, avoiding injections and drilling. It is one of a number of biologically oriented strategies for managing dental decay.
The technique has an evidence base showing that it is acceptable to children, parents and dentists and it is preferred over standard filling techniques, due to the ease of application and overall patient comfort as young patients do not have to undergo traumatic injections. Preformed metal crowns are now recommended as the optimum restoration for managing carious primary molars. There are multiple randomised controlled trials that have shown the Hall Technique to be superior to other methods for managing decay in baby teeth, but there is a lack of evidence to conclude that the Hall Technique is superior to placing preformed metal crowns in a conventional manner. Initial fears over the potential problem with sealing caries (cavities) into teeth being that the caries process might only be slowed, rather than arrested and that the caries might still progress, leading to pain and infection later.Innes NPT, Evans DJP, Stirrups DR. "The Hall Technique: a randomized controlled clinical trial of a novel method of managing carious primary molars in general dental practice; acceptability of the technique and outcomes at 23 months" BMC Oral Health 2007 7:18. https://www.biomedcentral.com/1472-6831/7/18Innes, N. P. T., Evans, D. J. P., & Stirrups, D. R. (2011). "Sealing caries in primary molars randomized control trial, 5-year results". Journal of Dental Research, 90(12), 1405-1410. This problem has not been realised with one study showing long-term data beyond five years, to when the baby teeth are lost, with fewer problems from the tooth with the crown.
Crowns placed using the Hall Technique have better long term outcomes (pain/infection and need for replacement) compared with standard fillings.Innes NPT, Evans DJP, Stirrups DR. "Sealing Caries in Primary Molars; Randomized Control Trial, 5-year Results". J Dent Res 2011 90(12) 1405-10. http://jdr.sagepub.com/content/90/12/1405.abstractInnes NPT, Marshman Z, Vendan R. "A Group of General Dental Practitioners' Views of Preformed Metal Crowns after Participation in the Hall Technique Clinical Trial; A Mixed-Method Evaluation". Primary Dental Care 2010 Jan; 17(1):33-7 http://www.ingentaconnect.com/content/fgdp/pdc/2010/00000017/00000001/art00017?crawler=trueGilchrist F, Howell J, Gavern D, North S, Innes NPT, Rodd HD. "Clinical outcomes for preformed metal crowns placed by dental undergraduates". Int J Paediatr Dent 2011, 21 (Suppl. 2): 1
The technique has been used and found particularly valuable in a developing country with little access to dental services, or resources to support such services.Fadil Elamin. "Saving children's teeth in Sudan – without anaesthetic or drills" It is also utilized in modern dental practices, as many parents and patients prefer treatment options that are minimally invasive and that help eliminate the need for sedation.
History
Preformed metal crowns have been used for restoring primary molars since the 1950s. Literature suggests preformed crowns placed on carious primary molar teeth reduce risk of major failure or pain in the long term compared to fillings. There is also evidence to suggest that fitting crowns using the Hall Technique reduces patient discomfort at the time of treatment in comparison to conventional fillings. It can also help reduce the overall time a patient spends in the dental chair due to the relatively simple and quick procedure when compared with traditional method of stainless steel crown (SSC) application.Innes, N. P. T., Ricketts, D., Chong, L. Y., Keightley, A. J., Lamont, T., & Santamaria, R. M. (2015). "Preformed crowns for decayed primary molar teeth" (Review).
The Hall Technique is named after Dr. Norna Hall, a dentist working in Scotland, who has developed a simplified technique where the crown is simply cemented over the carious primary molar, with no local anaesthesia, caries removal, or tooth preparation of any kind.Innes NPT, Stirrups DR, Evans DJP, Hall N. "A Novel technique Using Preformed Metal Crowns for Managing Carious Primary Molars in General Practice – a retrospective analysis" Brit Dent J 2006; 200(8):451-4 & 444 https://www.nature.com/bdj/journal/v200/n8/abs/4813466a.html The traditional method for management of dental caries has evolved from the exclusive domain of techniques based on complete caries removal prior to tooth restoration. Norna Hall used pre-formed crowns and cemented over carious primary molars using a glass-ionomer luting cement, with no caries removal, tooth preparation, or local anaesthesia.
The Hall Technique has been included in a guideline of the Scottish Dental Clinical Effectiveness Programme (SDCEP) and has helped to drive change in how dentists manage decay in primary teeth from the traditional invasive surgical approach to the less-invasive biological management of decay.Morgan AG, Gilchrist F, Cowlam J, Rodd HD. "Comparative outcomes for Hall vs conventionally placed preformed metal crowns". Int J Paediatr Dent 2012; 22(Suppl. 2):17-18.McKinney A, Britton, KFM, Innes NPT, Cairns A. "The success of Hall Technique crowns on a student outreach clinic". Int J Paediatr Dent 2011; 21(Suppl. 2): 8-9.Foley JI. "Short communication: a pan-European comparison of the management of carious primary molar teeth by postgraduates in paediatric dentistry". Eur J Paediatr Dent 2012; 13(1):41-6.Innes NPT, Evans DJP. "Modern approaches to caries management of the primary dentition". Brit Dent J. 2013, 214(11) 559-566.Bark JE, Dean AA, Cairns AM. "Opinion and usage of the 'Hall Technique' amongst paediatric dental specialists in Scotland". Int J Paediatr Dent 2009; 19(Suppl. 2):11
Clinical trials have shown the technique to be effective; however it is not an easy, quick-fix solution to the problem of carious primary molars. The technique is not suited to every tooth, child or clinician, but it can be an effective method of managing carious primary molars. The Hall Technique should not be used when there are clinical or radiographic signs and symptoms of irreversible pulpitis or dental abscess. Radiographically, there should be a clear band of dentine between the carious lesion and pulp for a Hall Technique to be suitable.
Decay in baby teeth Baby teeth are known as primary teeth or deciduous teeth. Biologically oriented strategies for managing dental decay are considered by their proponents to have advantages for child patients receiving dental care as the techniques are less invasive and often avoid having to use local anaesthesia and drilling. They are also less destructive and potentially damaging for primary teeth. Five randomised control trials with children, on decayed primary teeth, have been carried out looking at incomplete, or no removal of decay. These have looked at how much pain and infection or repeated treatment biological techniques (including the Hall Technique) compare to other treatment techniques including complete caries removal. These "minimal intervention" approaches reduce some of the adverse consequences associated with carrying out restorative treatment: conservation of tooth structure and integrity, maintenance of maximum pulpal floor dentinal thickness, which reduces the impact on pulpal health;Murray, P.E., et al., "Remaining dentine thickness and human pulp responses". International Endodontic Journal, 2003. 36(1): p. 33-43. reduced pulp exposure, and less need for local anaesthesia if no vital dentine is being removed, which has been shown to reduce children's reported discomfort.Rahimtoola, S., et al., "Pain related to different ways of minimal intervention in the treatment of small caries lesions". Journal of Dentistry for Children, 2000. 67(2): p. 123-7.van Bochove, J.A. and W.E. Amerongen, "The influence of restorative treatment approaches and the use of local analgesia on children's discomfort". European Archives of Paediatric Dentistry, 2006. 7(1): p. 11-16
A Cochrane systematic reviewRicketts D, Lamont T, Innes NPT, Kidd E, Clarkson JE. "Operative caries management in adults and children". Cochrane Database of Systematic Reviews 2013; Issue 3. Art. No.: CD003808. DOI: 10.1002/14651858.CD003808.pub3. http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD003808.pub3/abstract has compared biologically oriented strategies (stepwise, partial and no-caries removal), with complete caries removal for managing decay in both primary and permanent teeth. Eight trials of 934 patients (1372 teeth) with outcomes reported for 1191 teeth were included in the analyses. The conclusion of the review was that for symptomless and vital teeth, biologically oriented strategies had clinical advantages over complete caries removal in the management of dentinal caries. Not only were there no differences in restoration longevity or in the numbers of teeth (or patients) experiencing pulpal pathology (pain or infection), but there were significantly less pulp exposures. For partial caries removal in primary teeth, this was a risk ratio of 0.24 [0.06,0.90], when caries were not completely removed.
Use of technique in the permanent dentition
The Hall technique can also be used with permanent first molars in some cases where prognosis is poor, such as where first permanent molars are hypomineralised, carious with poor prognosis but to be maintained until full eruption of second molars, or for cuspal coverage of endodontically treated teeth in minors with compliance issues preventing full coverage crown preparation.
Indications and contraindications
Indications Hall Technique stainless steel crowns (SSC) are indicated for primary molars in the following situations:
There is a proximal carious lesions where two or more surfaces have carious lesions. Radiographically, a clear band of dentine should be able to be seen between the carious lesion and the dental pulp, the carious lesion does not extend beyond the middle third of dentine, and there is a clear dentine bridge between the pulp and the cavity. Restoration of fractured primary molars In primary molars that may be affected by developmental problems both localized or generalized i.e. in cases of enamel hypoplasia, dentinogenesis imperfecta, amelogenesis imperfecta, molar incisor hypomineralisation (MIH). In patients who are at high risk of developing caries i.e. patients who have to undergo general anaesthesia for dental treatment due to rampant caries. To protect and restore teeth that may have extensive tooth tissue loss due to erosion, attrition or abrasion. As a support for some dental appliances e.g. space maintainers In patients with special needs or where regular oral hygiene is impaired leading to likely breakdown of regular direct restorations. In patients with partially submerged primary molars in order to maintain the mesiodistal space.
Contraindications Hall Technique stainless steel crowns are contraindicated in the following instances:
The patient is known to be sensitive or allergic to nickel unless approval is given from an allergist or dermatologist first. There is any evidence that the carious lesion has irreversibly damaged the pulp: radiographically there is no obvious clear band of dentine visible between the carious lesion and the dental pulp on the radiograph and/or there is periradicular radiolucency (furcation involvement) indicating infection or clinically – symptoms of irreversible pulpitis or pulpal necrosis More than half of the root has resorbed and the primary tooth is close to exfoliation. Where a tooth is so broken down as to be unrestorable with a preformed metal crown (PMC)
Procedure