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Trial registered on ANZCTR


Registration number
ACTRN12608000585325
Ethics application status
Approved
Date submitted
14/10/2008
Date registered
21/11/2008
Date last updated
16/07/2015
Type of registration
Retrospectively registered

Titles & IDs
Public title
Early loading of mandibular single implant overdentures using a novel implant and attachment system: A randomized controlled clinical trial with laboratory component
Scientific title
A randomized controlled clinical trial on the early loading of mandibular single implant overdentures using a novel implant and attachment system to resolve complete tooth loss in the mandible
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Total tooth loss- edentulism 3826 0
Condition category
Condition code
Oral and Gastrointestinal 4013 4013 0 0
Other diseases of the mouth, teeth, oesophagus, digestive system including liver and colon

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
The participants will be randomly allocated into 3 groups, 2 test groups (groups 1 and 2) and 1 control group (group 3). Test group 1 participants will each receive a single wide (8mm) diameter, roughened-surface, externally-hexed, screw-shaped implant (Max-8, Southern Implants, Irene, South Africa). This implant has been originally developed by its manufacturer for immediate placement in fresh extraction sockets of molar teeth. The novel attachment system that will be used with this type of implant is made-up of a custom-made large ball abutment (5.9 mm) with a corresponding large plastic cap. Test group 2 participants will each receive a single regular (4mm) diameter, roughened-surface, screw-shaped implant (Neoss International, Harrogate, UK). The attachment system that will be used with this type of implant is the Locator attachment system. The control group participants (group 3) will each receive a single regular (3.75mm) diameter roughened-surface, externally hexed, screw-shaped implant (Southern Implants, Irene, South Africa). The attachment system that will be used with this type of implant is the standard (2.25mm) ball abutment with gold matrix. Surgical implant placement procedures for all 3 groups will follow a standardized one stage surgical approach with healing abutment connected to implants at surgery. Each single implant will be placed at the midline of the edentulous mandible of each participant. All the surgical procedures for implant placement are one-off procedures.
The loading protocol adopted in this trial is an early loading protocol at 6 weeks and described as follows: After 6 weeks of healing after implant surgery, the healing abutments (for all groups) will be removed and the final abutments (corresponding the type of implant used in each group) will be fitted. A closed-mouth reline impression will be used to incorporate the corresponding matrix of each attachment into the mandibular denture of each participants thus converting into an implant overdenture.
Intervention code [1] 3548 0
Treatment: Devices
Comparator / control treatment
The regular diameter implant (Southern Implants, Irene, South Africa) together with its attachment system used for the control group has been successfully documented in the literature with several short-term randomized controlled clinical trials (Payne et al , 2003; Tawse-Smith et al, 2002) and hence used as control for test group 1 with the wide diameter implant and novel attachment system and for test group 2 which has regular diameter ( 4mm) implant and attachment system comparable to that of the control group but no documented published outcome available for their use yet. All procedures involved in the 3 groups are one-off procedures.
Control group
Active

Outcomes
Primary outcome [1] 4912 0
To determine the surgical outcome (success) of using single midline implants to support mandibular overdentures for 1 year following early loading protocol at 6 weeks. The implant success will be measured according to the criteria prescribed by Albrektsson and Zarb (1998) which require marginal bone loss around the implant to be < than 1.0 mm in the first year and < than 0.2 mm every year after. This will be determined using standardized peri-apical radiographic procedures (Payne et al 2001).
Timepoint [1] 4912 0
Assessment of baseline bone level will be carried out at 6 weeks post-op when implants are loaded with the overdentures. The measurement will then be repeated 1 year later. Each participant will be subjected to one measurement annually. The marginal bone level measurements will be carried out using standardized peri-apical radiographs.
Secondary outcome [1] 8296 0
To determine the prosthodontic outcome of mandibular single implant overdentures following early loading protocol at 6 weeks. The prosthodontic outcome will be measured by recording all maintenance events that will be endured by the implant overdenture starting from baseline (6 weeks post-op) up to the end of first year of service. These maintenance events will be allocated to 1 of 12 different categories of following the proposal of Payne et al (2001). The outcome of the implant overdenture at the end of the first year of service (based on these categories) will then be assigned to 1 of 6 objectively defined outcome fields: Success, Survival, Unknown, Dead, Retreatment (repair), and Retreatment (replace) otherwise known as the Six-Field Protocol for Implant Overdentures (Payne et al, 2001).
Timepoint [1] 8296 0
The maintenance events recording will start from baseline (6 weeks post-op) which corresponds to the start of loading and continues all through and up to the end of the first year of service.

Eligibility
Key inclusion criteria
Elderly edentulous patients with history of difficulties with their complete mandibular dentures and with minimum height and width of bone at the midline of the mandible to accommodate a 7X8 mm diameter implants
Minimum age
50 Years
Maximum age
90 Years
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Exclusion criteria: Any systemic or local condition contradictory to implant surgery; Bruxism, Irradiated or grafted jaws; Smoking > 10 cigarettes a day; Drug abuse; Un-willingness to attend regular recalls.

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Patients meeting the inclusion and exclusion criteria were enrolled and allocated to interventions using sealed envelopes
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Type of endpoint(s)
Efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Active, not recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment outside Australia
Country [1] 1278 0
New Zealand
State/province [1] 1278 0

Funding & Sponsors
Funding source category [1] 4008 0
Commercial sector/Industry
Name [1] 4008 0
Southern Implants
Address [1] 4008 0
Southern Implants, No. 1 Albert Road Irene 1675, South Africa
Country [1] 4008 0
South Africa
Primary sponsor type
Commercial sector/Industry
Name
Southern Implants
Address
Southern Implants, No. 1 Albert Road Irene 1675, South Africa
Country
South Africa
Secondary sponsor category [1] 3600 0
Commercial sector/Industry
Name [1] 3600 0
Neoss International
Address [1] 3600 0
Neoss International, Windsor Building, Cornwall Road, Harrogate, HG1, 2PW, UK
Country [1] 3600 0
United Kingdom

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 6087 0
Lower South Regional Ethics Committee
Ethics committee address [1] 6087 0
Ethics committee country [1] 6087 0
New Zealand
Date submitted for ethics approval [1] 6087 0
Approval date [1] 6087 0
Ethics approval number [1] 6087 0

Summary
Brief summary
This study aims to test a new implant overdenture treatment design that is surgically less invasive and more affordable to elderly patients. It uses only a single wide implant in the middle of the lower jaw and a new attachment system that would hopefully require less maintenance. The pool of participants will be from the Oral Implantology Research Group, Sir John Walsh Research Institute, School of Dentistry, University of Otago, Dunedin, New Zealand. The hypothesis to be tested are:
The first hypothesis is that there is no difference in the success rate between single wide diameter implants and standard diameter single implants supporting lower jaw overdentures for one year after early loading protocol at 6 weeks after surgical placement.
The second hypothesis is that there is no difference in the prosthodontic maintenance in the first year of service of lower jaw overdentures supported by single wide diameter implants and that of lower jaw overdentures supported by single regular diameter implants
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 29034 0
Address 29034 0
Country 29034 0
Phone 29034 0
Fax 29034 0
Email 29034 0
Contact person for public queries
Name 12191 0
Dr Alan Payne
Address 12191 0
Oral Implantology Resaearch Group
Sir John Walsh Research Institute
School of Dentistry
University of Otago
Great King Street, Dunedin 9016, New Zealnd
Country 12191 0
New Zealand
Phone 12191 0
+ 64 3 479119
Fax 12191 0
+ 64 3 4795079
Email 12191 0
alan.payne@dent.otago.ac.nz
Contact person for scientific queries
Name 3119 0
Dr Alan Payne
Address 3119 0
Oral Implantology Resaearch Group
Sir John Walsh Research Institute
School of Dentistry
University of Otago
Great King Street, Dunedin 9016, New Zealnd
Country 3119 0
New Zealand
Phone 3119 0
+ 64 3 479119
Fax 3119 0
+ 64 3 4795079
Email 3119 0
alan.payne@dent.otago.ac.nz

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