The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Prospectively registered

Titles & IDs
Public title
The Hall technique in preschool children
Scientific title
Effectiveness of a simplified method of managing carious primary molar teeth in preschool children using preformed metal crowns- (Hall technique) Phase 1
Secondary ID [1] 280364 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
dental caries 286337 0
Condition category
Condition code
Oral and Gastrointestinal 286581 286581 0 0
Other diseases of the mouth, teeth, oesophagus, digestive system including liver and colon

Study type
Description of intervention(s) / exposure
Modified stainless steel crown technique on primary molars
to seal in caries
Review 6 and 12 months after placement
Duration : 15 minutes on one visit
Intervention code [1] 284730 0
Treatment: Surgery
Comparator / control treatment
no control group
Control group

Primary outcome [1] 287002 0
Percentage of failure at 12 months

Failure classified into major and minor failure

Abscess or irreversible pulpitis in the tooth with the Hall's crown will be classified as a 'Major failure', whilst 'minor failures' would be: caries at the margin of the crown, crown worn through, crown lost, first permanent molar impacting and separator placed.
A 'Successful' outcome is a tooth with a Hall crown that has neither a 'Major' or 'Minor' failure.
The assessment will be through both clinical and radiographic assessment
Timepoint [1] 287002 0
at 6 months and 12 months after placement of Hall crown
Secondary outcome [1] 297179 0
Acceptability of Hall technique to public oral health practitioners, preschool children and their primary carers
Assessment via questionaires administered verbally to primary carers and structured interviews with public oral health practitioners
Timepoint [1] 297179 0
at placement of Hall crowns and at 12 months after placement

Key inclusion criteria
greater than 3 years of age and less than 6 years of age
high risk of decay
co-operative for radiographs and treatment in dental clinic
Minimum age
36 Months
Maximum age
71 Months
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
at risk of infective endocarditis

Study design
Purpose of the study
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Who is / are masked / blinded?

Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Active, not recruiting
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 285146 0
Name [1] 285146 0
Dental Health Services Victoria
Address [1] 285146 0
720 Swanston St
Carlton 3053
Country [1] 285146 0
Primary sponsor type
Dental Health Services Victoria
720 Swanston St
Carlton 3053
Secondary sponsor category [1] 284003 0
Name [1] 284003 0
The University of Melbourne
Address [1] 284003 0
720 Swanston Street
Parkville 3053
Country [1] 284003 0
Secondary sponsor category [2] 284004 0
Name [2] 284004 0
North Richmond Community Health Centre
Address [2] 284004 0
23 Lennox Street
Richmond 3121
Country [2] 284004 0

Ethics approval
Ethics application status
Ethics committee name [1] 287155 0
Dental Health Services Victoria Human Research Ethics Committee
Ethics committee address [1] 287155 0
720 Swanston Street
Carlton 3053
Ethics committee country [1] 287155 0
Date submitted for ethics approval [1] 287155 0
Approval date [1] 287155 0
Ethics approval number [1] 287155 0

Brief summary
There are a large number of disadvantaged pre-school children who suffer tooth decay. Unfortunately, many of them require extensive treatment necessitating general anaesthesia with its risks and high costs. Preformed stainless steel crowns are the best method of restoring decayed baby molar teeth and a simplified method of placing them, without using general anaesthesia, has been found to be successful with school age children. We wish to test whether this method would be successful with pre-school children at high risk to dental caries in a community dental clinic at a success rate comparable to conventionally placed stainless steel crowns.
Research Investigators include the Director of Clinical Leadership, Education and Research of Dental Health Services Victoria; senior academic staff of the Melbourne Dental School, University of Melbourne; the Manager Oral Health Program North Richmond Community Health, and a senior dentist from the North Richmond Community Dental Clinic. Participants will include North Richmond Community Health management and staff, preschool children patients (and their primary carers) of the North Richmond Community Dental Clinic. As part of the standard clinical care for patients at high risk to dental caries, the preschool children will have x-rays taken beforehand to diagnose decay and exclude from the study patients with extensive disease for which this treatment is not indicated. Multi-language brochures and dental examination with questionnaire will precede an interview to elicit verbal and written consent. Immediately after treatment, carers will be asked to fill in another questionnaire. At the 12 months review visit another x-ray will be taken, again according to standard clinical care for patients at high risk to dental caries, and a further questionnaire filled. The prime statistic will be the number of crowns deemed to be a success at six months, and 12 months (for Phase 1 of the study), using criteria established by previous research. Secondary findings will be the acceptance of this mode by patients, carers and staff.
A key aspect is that, in appropriately selected cases, this treatment does not drill out any of the decay; so, does not require any injection of local analgesia, is less uncomfortable, and so is faster and likely to be better tolerated by pre-school children than conventional stainless steel crowns. A key issue is ascertaining that there is no unexpected progression of decay with poor outcomes. Research has shown that the decay of deciduous molars that is isolated under the crowns ceases and causes no further destruction to the teeth.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 34093 0
A/Prof Hanny Calache
Address 34093 0
720 Swanston Street
Victoria 3053
Country 34093 0
Phone 34093 0
+61 3 93411291
Fax 34093 0
Email 34093 0
Contact person for public queries
Name 17340 0
Dr Rachel Martin
Address 17340 0
Dental Health Services Victoria
720 Swanston Street
Carlton 3053
Country 17340 0
Phone 17340 0
61 3 9341 1720
Fax 17340 0
Email 17340 0
Contact person for scientific queries
Name 8268 0
A/Prof Hanny Calache
Address 8268 0
Dental Health Services Victoria
720 Swanston Street
Carlton 3053
Country 8268 0
Phone 8268 0
61 3 9341 1291
Fax 8268 0
Email 8268 0

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary