Condition category
Oral Health
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
There are 3.7 million people in Britain who have no natural teeth and most are over 65. Many of these individuals have difficulty wearing lower dentures, which causes difficulties in chewing and speaking resulting in a significant impact on quality of life, so much so that the World Health Organisation classifies these individuals as having a disability. Titanium implants screwed into the jaw hold lower dentures in place. Mini-implants have recently been developed. They are smaller and cheaper than traditional implants and are less painful to place. However, the long-term costs and benefits of mini-implants have not been compared with traditional implants. We will therefore undertake an initial study to compare mini-implants with traditional implants.

Who can participate?
Patients lacking teeth, who are referred to Manchester University Dental Hospital and meet the eligibility criteria will be able to take part.

What does the study involve?
After some initial tests patients will be randomly assigned to receive either mini or traditional implants. An appointment will be made for these to be fitted and the patients will also attend 1 week, 2 months & 6 months after surgery in order to make further assessments. Patients will need to complete a chewing test and questionnaires at these visits. Patients who receive the mini implants may find the surgery less painful but it is possible the implants may not be as long lasting. After the study the outcomes in the 2 groups will be analysed. The initial study will also tell us how quickly we can recruit patients and how many will stay once they have been recruited. The study will also help us build a team and give information on how to effectively manage a large-scale study.

What are the possible benefits and risks of participating?
Placing both types of implants requires a minor operation. The operation for the traditional implant is more extensive and may produce more pain and swelling. Any surgical procedure has risks of bleeding and infection. There is also a small risk of nerve damage or jaw fracture. Once it has been decided which implant you will receive the surgical team will discuss the procedure and potential side effects with you in greater detail. If you receive the mini implants you may find the operation easier to undergo but as the implants are smaller there is a chance that they might not be as long-lasting. Participating in the study does not require you to attend any additional appointments but appointments may take a little longer as we need to measure how well you can chew and you will need to complete several questionnaires. In total it may take 20 to 30 minutes to complete questionnaires at each visit, plus a few minutes for the chewing test. If you don’t want to spend the extra time doing these tests you do not have to take part in the study.

Where is the study run from?
Manchester University Dental Hospital (UDHM) (UK)

When is study starting and how long is it expected to run for?
Patient recruitment is planned to start in September 2013 and will take place over one year.

Who is funding the study?
The study is funded by the National Institute of Health Research (NIHR), UK (Research for Patient Benefit funding stream), with the supply of mini implants funded by the manufacturer (3M).

Who is the main contact?
Helen Flight

Trial website

Contact information



Primary contact

Mrs Helen Flight


Contact details

550 Wilmslow Road
M20 4BX
United Kingdom
+44 (0)161 446 3000

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

A pilot randomised controlled trial of Conventional Implants vs Mini Implants used to retain full lower DENTures



Study hypothesis

Titanium implants screwed into the jaw hold lower dentures in place, but implants are costly and require surgery that some patients may not cope with. Mini-implants have recently been developed; they are smaller and cheaper than conventional implants and are much less traumatic to place. However, the long-term costs and benefits of mini-implants have not been compared with conventional implants in high quality clinical trials. This pilot trial will gather the necessary information to inform a future large scale trial of conventional versus mini implants.

Ethics approval


Study design

Randomised; Interventional; Design type: Not specified, Treatment

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use contact details to request a participant information sheet


Topic: Oral and Gastrointestinal; Subtopic: Oral and Gastrointestinal (all Subtopics); Disease: Oral & Dental


1. Conventional dental implant (Astra)
2. Mini Dental Implant (3M)

Intervention type



Not Applicable

Drug names

Primary outcome measure

Inform a large randomised trial of conventional vs mini implants; Timepoint(s): Throughout conduct of the pilot trial, each patient is followed-up for 6 months post surgery.

Secondary outcome measures

Not provided at time of registration

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Patient has been edentulous (no teeth at all) for at least 12 months
2. Bone height = 10mm in the interforamina region (anterior section of the mandible), therefore suitable for implant placement without bone grafting
3. Cawood and Howell Classification V and VI (severely resorbed mandible)
4. New lower denture remains unsatisfactory
5. Able to give informed consent to participate in the study
6. Aged 18 or over
Target Gender: Male & Female ; Lower Age Limit 18 years

Participant type


Age group




Target number of participants

Planned Sample Size: 44; UK Sample Size: 44

Participant exclusion criteria

1. Radiographic confirmation that the patient has insufficient mandibular bone for either procedure
2. Significant medical history contraindicating the placement of either conventional or miniimplants (e.g. bisphosphonate treatment, radiotherapy treatment, poorly controlled diabetes, longterm steriod use)
3. Current smoker, or have smoked in last six months
4. Unable to maintain adequate level of oral hygiene
5. Requires sedation for dental treatment
6. Previous failed implant treatment
7. Allergic to or unable to tolerate any of the ingredients of ‘gummy jelly’ (an outcome measure)

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

550 Wilmslow Road
M20 4BX
United Kingdom

Sponsor information


Central Manchester University Hospitals NHS Trust (CMFT) (UK)

Sponsor details

Genetic Medicine
Manchester Royal Infirmary
Oxford Road
M13 9WL
United Kingdom

Sponsor type

Hospital/treatment centre



Funder type


Funder name

NIHR Research for Patient Benefit (RfPB) (UK) Grant Codes: PB-PG-0212-27050

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

2017 results in:

Publication citations

Additional files

Editorial Notes

17/02/2017: Publication reference added.