Hall Crowns: A Simple Non-Invasive Restorative Technique that is Highly Successful
The Hall Crown
Dental caries is a multifactorial, dynamic process with host, genetic, environmental and behavioural components. It is a result of dysbiosis both in the entire oral cavity and at the tooth surface. As such, it is not an infectious disease that can be surgically ‘cut out of a tooth’. The cavity is merely the outcome of the disease process.
As our understanding of dental caries has changed, our ability to treat it has also changed. This has led to the advent of Minimally Invasive Dentistry (a topic for another day). This is not a philosophy of ‘smaller fillings’, but an acknowledgement of the finite life-span of a restoration irrespective of how well it is placed. One such excellent and minimally invasive restoration is a Hall-crown, which does not remove the caries present and takes advantage of our increased knowledge of the caries process.
What is a Hall-Crown?
A Hall-crown in a non-invasive technique that uses the most successful restorative material available in primary teeth; a stainless-steel crown (SSC). It is placed over an entire tooth without using a handpiece, or local-anaesthetic and aims to entomb the bacteria present and deprive them of any future food source. This is successful because the seal created, if placed properly, is unlikely to degrade or leak, such as what occurs for intracoronal restorative materials.
Is it Actually Successful?
When this technique was first discovered, there was a great deal of scepticism as to whether this was an appropriate procedure to perform on children. One excellent study conducted by BaniHani et all (2019) compared the conventional SSC approach (full caries removal + / - pulpotomy where required) to the Hall Crown (with or without selective caries removal). The success rate at 77 months (6.4 years) was: 95.3% for the conventional crowns and 95.8% for the Hall Crowns. No statistical difference was recorded. A very promising result, particularly when you compare the success of intra-coronal restorations at around 50 – 80% at 3 years depending upon the material selected.1
Caries #84DO (ICDAS 4)
What Are the Criteria to Perform a Hall Crown?
As for any procedure, the most important factor for success is the criteria used to determine if the treatment is appropriate or not. This CANNOT be understated and if you want to begin employing this technique in your practice you NEED to follow several rules. There could be no worse outcome than performing a procedure with a high chance of failure in a child with limited compliance (as the next step is an extraction…).
So what are the criteria?
• Vital pulp with no signs or symptoms of irreversible pulpitis, necrosis or an abscess
• No pathological mobility
• The tooth is restorable (adequate remaining tooth structure)
• No medical contraindications (cardiac, infection…)
• Take a radiograph prior (THIS IS A MUST)
• Ensure a clear band of dentine
• Ensure the patient and parents are accepting of the aesthetics. 2
Seperators To Create Space To Place The Crown
One major point we want to emphasize here is that you must have a radiographic assessment prior to placing a Hall Crown. This is the same as for placing any restoration in a primary tooth. If you fail to take a radiograph prior to performing a restorative procedure in a child, you are setting yourself up for a failure. If you are unable to take a radiograph in the child, this is an indication that their compliance will likely prevent you from being able to perform the most appropriate treatment and to follow up on the success of your treatment. Consideration should be given to referral to a paediatric dentist .
Post-Cementation of a Hall Crown
So How Do You Do a Hall Crown?
To not make our posts too long, we will leave this for the next post!
We hope this has been of some help!
Sarah and Tim
References
1. BaniHani A, Deery C, Toumba J, Duggal M. Effectiveness, Costs and Patient Acceptance of a Conventional and a Biological Treatment Approach for Carious Primary Teeth in Children. Caries Res 2019;53:65-75.
2. Innes N, Evans D, Stewart M, Keightley A. The Hall Technique: A minimal intervention and child friendly approach to managing the carious primary molar. 2015.