1. MDSc LDS FRACDS FICD FACD
Simplified Method of Using Preformed Metal Crowns in Preschool Children
H. CALACHE, J. BROWNBILL, D.J. MANTON, R. MARTIN, M. HALL, and K. SIVASITHAMPARAM
Clinical Associate Professor
John W BROWNBILL
MDSc LDS FRACDS FICD FACD
Paediatric Dentistry
Melbourne Dental School
The University of Melbourne
Bula
This is my second presentation to IADR ANZ, the first was in 1969!
One of the things that I have been doing since my retirement has been training public sector clinicians in
treatment of pre-school children.
Following the work of Evans and Innes, I was training them in the placement of stainless steel crowns
(SSC) using the Hall technique in selected cases. It is pretty easy to do.
The average time that they took doing their first one, from selection to cementation was two minutes.

2. This presentation will discuss the study protocol
and recruitment method including
calibration of examiners in the use of ICDAS II
and a radiographic scoring method.
This presentation will discuss the study protocol
and recruitment method including
calibration of examiners in the use of ICDAS II
and a radiographic scoring method.
September 2012
IADR ANZ APR FIJI

3. Preformed stainless steel crowns (SSC)  give carious deciduous molar teeth the best prognosis compared to other restorations.
A simplified method, without cavity preparation, the Hall Technique, has been reported to be successful with school age children.
We will test this method with pre-school children from an inner urban community.
A brief summary of the technique is that the teeth are not prepared in any way
except for the removal of gross debris but no caries excavation.
SSC are tested to just resist passing the contacts, the “springback”.
The crowns are filled with glass ionomer cement
and pushed gently but firmly as far as they will go.
Emphasis is placed on safety with the child bolt upright,
gauze protection of the airway at all times and the rapid removal
of excess cement before the tongue gets an acid taste.
The combination of crown extending beneath the gingival margin,
the leak free quality of GIC squeezed tightly into place and the distance from the oral
environment to the lesion margin means that the caries is sealed and ceases.
September 2012
IADR ANZ APR FIJI

4. Objectives:
To determine the success of the Hall Technique to manage caries within the outer half of dentine in pre-school children,
and to determine the acceptability of the Hall Technique to clinicians, children and their carers.
Legitimate concerns were raised about the validity of this treatment for preschool children
as all the literature reports have been on children whose first permanent molars had erupted.
It is well established that traditional SSC are the most
effective restorative treatment for primary molars,
most being placed in preschool children using general anaesthesia (GA).
The simpler nature of the Hall technique compared to the
traditional SSC gives the potential for more cases to be treated without needing GA.
We opined that the rigours of a double blind study were not indicated and that all
we needed to do was show that the failure rate was comparable to traditional SSC,
with no significant morbidity.
September 2012
IADR ANZ APR FIJI

5. no relevant medical history;
Methods:
The study is a non-controlled prospective clinical trial at a community clinic. Inclusion criteria: 3, 4 or 5 years-old on day of recruitment;
no relevant medical history;
one or two primary molars with caries within the outer half of dentine;
no pulpal symptoms;
no inter-radicular radiolucency on selected primary molar teeth;
informed consent from parent
and acceptance of treatment by child.
The study is a non-controlled prospective clinical trial at a community clinic.
Inclusion criteria: 3, 4 or 5 years-old on day of recruitment;
no relevant medical history;
one or two primary molars with caries within the outer half of dentine;
no pulpal symptoms;
no inter-radicular radiolucency on the selected primary molar teeth;
informed consent from the parent
and acceptance of treatment by the child.
September 2012
IADR ANZ APR FIJI

6. Hypothesis
The Hypothesis is that the failure rate for the Hall Technique will be similar to the conventional SSC (7%) 12 months after insertion.
ref: Randall, R.C., Vrijhoef, M.A., and Wilson, N.H.F. Efficacy of preformed metal crowns vs amalgam restorations in primary molars; a systematic review. Journal of the American Dental Association 2000, 131; )
The Hypothesis is that the failure rate for the Hall Technique will be similar
to the conventional SSC (7%) 12 months after insertion.
September 2012
IADR ANZ APR FIJI

7. Concerns Expressed Sealing Caries Occlusal Vertical Dimension Increase
Impaction of Ectopically Erupting First Permanent Molars
Concerns expressed have been
Sealing caries inside teeth
Occlusal Vertical Dimension (OVD) Increase
Impaction of Ectopically Erupting First Permanent Molars
September 2012
IADR ANZ APR FIJI

8. Sealing Caries Concerns Expressed
hermetically sealing the caries biofilm will stop the progress of the lesion (Cochrane Systematic Review, 2006).
Innes NPT, Stirrups DR, Evans DJP, Hall N. A Retrospective Analysis of a Novel Technique Using Preformed Metal Crowns for Managing Carious Primary Molars in General Practice British Dental Journal (8):451-4 & 444.
Concerns expressed have been that sealing in caries
may lead to continuation of the caries and pulp pathology.
The caries could just as well be described as being sealed out.
I prefer the term sealing of caries.
The caries process is driven by the plaque biofilm,
located on the surface of the carious lesion.
If a caries lesion is isolated from the oral environment,
the plaque biofilm composition will alter to a less cariogenic flora.
Therefore, hermetically sealing the caries biofilm will stop the progress of the lesion.
Innes and co-workers found no progress of caries under Hall technique crowns
September 2012
IADR ANZ APR FIJI

9. Occlusal Vertical Dimension Increase
Concerns Expressed
Occlusal Vertical Dimension Increase
Innes NPT, Stirrups DR, Evans DJP, Hall N. A Retrospective Analysis of a Novel Technique Using Preformed Metal Crowns for Managing Carious Primary Molars in General Practice British Dental Journal (8):451-4 & 444.
van der Zee V, van Amerongen WE. Short communication: Influence of preformed metal crowns (Hall technique) on the occlusal vertical dimension in the primary dentition. Eur Arch Paediatr Dent Oct;11(5):225-7.
Occlusal Vertical Dimension (OVD)
As the Hall technique does not involve any occlusal reduction of the tooth, it is inevitable that placing a crown will result in a premature contact and an increase in the OVD [Innes et al., 2006].
In the experience of Innes et al., [2006; 2007] the occlusion re-establishes within a few weeks.
It is common knowledge that traditional SSC left inadvertently high in occlusion return to normal; however, no proof of that could be found in the literature.
Part of controlled clinical trial (van der Zee, and van Amerongen, 2010), was designed to investigate the influence of Hall PMC on the occlusal vertical dimension.
Their weak numbers showed that the occlusion returned back to the pre-treatment situation within days.
Our two crowns on one patient to return for review had returned to normal in 15 days.
With our early crowns we are testing physical and photographic methods of measuring OVD and hope to develop a method to use in a subset of our patients to find an answer
to the time taken to return to normal.
September 2012
IADR ANZ APR FIJI

10. Impaction of Ectopically Erupting First Permanent Molars
Concerns Expressed
Impaction of Ectopically Erupting First Permanent Molars
It is anecdotal that first permanent molars may be impacted under the margins of SSC if erupting ectopically.
With our numbers we do not expect any cases; however, if there were they would be treated more easily than usual
as it is simply a matter of removing the offending crown, allowing eruption, then replacing with a smaller crown.
September 2012
IADR ANZ APR FIJI

11. Calibration and training of dental staff
Clinicians were trained in:
ICDAS II for clinical examination
Standardized Clinical Radiographic diagnosis,
Hall Technique for crown placement on deciduous molar teeth
To ensure that our clinicians were not treating cases that had already undergone irreversible pulp pathology,
they were trained and calibrated in The International Caries Detection and Assessment System II and radiographic caries diagnosis.
Lesions treated were no closer than halfway to the pulp radiographically.
September 2012
IADR ANZ APR FIJI

12. Calibration and training of dental staff
Only the dentists calibrated and trained verify the cavities and place Hall Technique crowns.
All others who examine use ICDASII to identify suitable cases.
Our pool of patients are treated by dentists and therapists at two sites close to each other.
September 2012
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13. Trial recruitment Some key staff have particular tasks:
ensuring clinic supplies and equipment
study form collection and collation
initial parent response questionnaires.
The community dental clinic employs locals and responds to the community cultures.
The staff have strong connections with the families in the community.
All dental staff at North Richmond Community Health Centre are involved.
Most are locals well known to families.
September 2012
IADR ANZ APR FIJI

14. Trial recruitment
Maternal and Child Health Services are in the same building with the dental service and are a source of recruits for the study.
The dental service is a partner in “Smiles 4 Miles” and has regular preschool visits and screenings.
Maternal and Child Health Services are co-located in the building and are a source of recruits for the study.
The dental service is a partner in “Smiles for Miles” and has regular preschool visits and screenings.
September 2012
IADR ANZ APR FIJI

15. 4 = Dentinal shadow (not cavitated into dentine)
Suitable caries for the Hall technique is in the ICDASII score range of 4 to 6:
4 = Dentinal shadow (not cavitated into dentine)
5 = Distinct cavity with visible dentine
6 = Extensive distinct cavity with visible dentine
ICDASII The International Caries Detection and Assessment System (ICDAS): an integrated system for measuring dental caries.Ismail AI, Sohn W, Tellez M, Amaya A, Sen A, Hassan H, Pitts NB. Community Dent Oral Epidemiol Jun;35(3):170-8.
Suitable caries for the Hall technique is in the ICDASII score range of 4 to 6:
September 2012
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16. Radiographic diagnosis
We want to ensure that radiographically, the caries has not extended to a point where there may be a possibility of pulp necrosis, hence we chose the midpoint of the dentine as being the maximum extent of caries we would accept radiographically
A scoring system for radiograph interpretation was adapted by Dr Denise Bailey, from Melbourne Dental School (After Mejare 1999)
In the planning of treatment for traditional SSC it is recommended that peri-radicular radiography is used to exclude pathology.
We have included this requirement in our protocol.
It has proved difficult because the children in our target group are less able to tolerate the bitewings,
or stand still for panoramic, than they are able to cope with the Hall technique.
Unfortunately, many in our target group are not suitable because of lesions being already too deep,
behaviour issues or reluctance to consent.
If anyone has some clues for us about radiographic techniques for preschoolers or how to raise
consent ratios amongst the eligible, we would be very happy to take note of them.
September 2012
IADR ANZ APR FIJI

17. Hall technique Training
Three dentists have been trained in placing crowns with emphasis on safety and diagnosis and have commenced placing 220 crowns.
The two particular safety issues relate to preventing aspiration of a crown.
They are:
Keeping the child bolt upright and using gauze as an airway protector.
The gauze is useful in wiping away excess GIC before the vinegary taste upsets the children.
September 2012
IADR ANZ APR FIJI

18. Data being collected includes: time taken for procedure;
Data Collection
Data being collected includes:
time taken for procedure;
occlusal vertical dimension change;
acceptability to child
acceptability to parent
acceptability to dentist
Data being collected includes:
time taken for the procedure;
occlusal vertical dimension change;
acceptability to the child
acceptability to the parent
acceptability to the dentist
September 2012
IADR ANZ APR FIJI

19. Follow up
Clinical review of all teeth with Hall crowns at 6 and 12 months with radiographic review at 12 months
A ‘Successful’ outcome is a tooth with a Hall’s crown that has neither a ‘Major’ nor ‘Minor’ failure.
Abscess or irreversible pulpitis in the tooth with the Hall’s crown is classified as a ‘Major failure’
‘minor failures’ are: caries at the margin of the crown, crown worn through, crown lost, first permanent molar impacting.
Success of the Hall Crowns over the period of the study will be measured according to their retention
without evidence of any adverse clinical or radiological signs and symptoms.
The outcome criteria used for the clinical and radiographic assessment
of the Hall technique is in line with ‘Succesful’, ‘Major failure’ and ‘Minor Failure’ used by Innes et al (2011)
September 2012
IADR ANZ APR FIJI

20. five of 220 crowns have been placed to date.
Very early results:
Weighted Kappa values of examiners showed >0.6 (good) and >0.8 (excellent) agreement with the gold standard for ICDAS II calibration.
All examiners showed generally excellent agreement with themselves between sessions.
five of 220 crowns have been placed to date.
Occlusion returned to baseline within 30 days for two crowns placed on one participant.
To date approximately 60 preschool children have been assessed for suitability for the Hall technique, with 6 children found to fill the criteria.
There was intra and inter examiner agreement in caries assessment.
Many children are caries free and a few have multiple deep lesions,
meaning that we need to examine more children than we expected to find suitable cases.
Our progress has been slower than we hoped.
September 2012
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21. Professor Brownbill is self-funded for this presentation.
This study is supported by a grant from Dental Health Services Victoria from whom ethics approval was obtained. The chief researcher is Adjunct Professor Hanny Calache, Director of Clinical Leadership, Education and Research, Dental Health Services Victoria. Researchers are Professor David Manton and Clinical Associate Professor John Brownbill of Melbourne Dental School; and Dr Martin Hall and Dr Kavitha Sivasithamparam of North Richmond Community Health Centre. Research Co-ordinator is Dr Rachel Martin of Dental Health Services Victoria.
Professor Brownbill is self-funded for this presentation.
Thank you for your attention.
We have ethics approval and a grant from Dental Health Services Victoria
and enthusiastic support from the North Richmond Community Health Centre
and The University of Melbourne Dental School.
Thank you
September 2012
IADR ANZ APR FIJI

22. ICDASII Calibration Method
Information was recorded using an ICDAS II recording form
All were shown photos of 20 tooth surfaces and asked to code them on three separate occasions using only ICDASII caries codes
The order of the 20 photos was changed each time
The recording forms were inspected for consistency and identification of under or over scoring
Calibration was undertaken at the NRCH centre utilising digital photographs (ICDASII) projected on a screen under the same conditions on each of three occasions
ICDSII codes 4 to 6 were more heavily represented in the calibration exercise
as this is the caries that the Hall technique is used to treat
September 2012
IADR ANZ APR FIJI

23. Code Category Diagnostic criteria R0 Sound
No radiolucency or restoration R1
Outer half enamel lesion
Zone of distinct radiolucency confined to outer half of enamel (no minimum limit) up to, but not including half way R2
Inner half enamel lesion
Zone of distinct radiolucency involving both inner and outer halves of the enamel, including lesions extending up to but not beyond the ADJ R3
Lesion with broken Amelo-dentinal Junction (ADJ) border
Zone of distinct radiolucency penetrating enamel with a broken ADJ border but with no obvious progression into dentine R4
Outer ½ dentinal lesion
Zone of distinct radiolucency penetrating enamel and ADJ but confined to the outer half of dentine R5
Inner ½ dentinal lesion
Zone of distinct radiolucency penetrating into the inner half of the dentine with or without apparent pulpal involvement
We accept codes of R3 or R4.
After Mejare 1999, modified by D Bailey OHCRC 2012
September 2012
IADR ANZ APR FIJI