Condition category
Not Applicable
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Plain English Summary

Not provided at time of registration

Trial website

Contact information



Primary contact

Mr T Paul Hyde


Contact details

Leeds Dental Institute
Clarendon Road
Leeds University
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Improving dentures for patient benefit: a single centre randomised, controlled, crossover clinical trial comparing materials for complete dentures



Study hypothesis

The aim of this study is to significantly impact on the quality of denture production within NHS dentistry. To achieve this objective, we aim to provide evidence of effectiveness and cost-effectiveness of a development in denture impression materials. The aim is to ask the patients to provide the outcome assessments for the trial; a user-centered approach which will give clinically significant results, empower research participants and facilitate a deeper understanding of patients' denture wearing problems.

Ethics approval

Not provided at time of registration

Study design

Single-centre randomised controlled cross-over clinical trial

Primary study design


Secondary study design

Randomised cross over trial

Trial setting


Trial type


Patient information sheet

Not available in web format. Please use the contact details below to request a patient information sheet.


Quality of denture production


Patients should be assessed for their suitability to participate in this study before they give their consent and are registered into the trial.

Denture construction:
The Prosthodontic Research Team at the Leeds Dental Institute has developed and published a method of producing two or more sets of dentures which are clinically identical apart from the one deliberate alteration which is to be the subject of this trial. This methodology will be used to produce two sets of dentures which are clinically identical apart from the impression material that was used to provide the mould for the fitting surface of each denture.

Patients will be given both sets of dentures for a 2-week habituation period. During the 2 weeks the patients will be provided with a diary and asked to record the wearing of each set of dentures. They will then be asked to score each denture for comfort, mobility and chewing efficiency using a 5-point Likert scale. Both sets of dentures will be returned and re-marked for the adjustment stage. The code will be blind to clinicians and patients, and kept confidential until the end of the trial.

Dentures will be given back to patients, one at a time over two adjustment periods (8 weeks each), in random order. If any adjustment or remedial work is required to make the dentures comfortable, retentive and useful this will be carried out by an experienced clinician. Within the limits of the LDI appointment system there will be no restriction on the number of appointments the patients can request during these two 8-week periods. Every appointment requested by the patient will be noted and a detailed record of the work required will be kept. At the end of each 8-week adjustment period the patient will be asked to attend and report the impact the dentures have had on their quality of life by the completion of a OHIP-EDENT and EQ-5D questionnaires and will rate the denture for comfort, mobility and chewing efficiency using 5-point Likert Scales.

After the two adjustment periods of 8 weeks it is to be expected that each set of dentures will be as good as it is possible to make them. The patient will be asked to take both sets of dentures away for a 2-week confirmation period and return for a final visit to express any preference for the dentures and perform a Likert assessment of comfort, mobility, and chewing efficiency.

Intervention type



Not Applicable

Drug names

Primary outcome measure

Patient preference for unadjusted dentures and overall cost-effectiveness, measured at the end of the habituation period. Patient preference will be established by asking whether one or other denture is preferred, or whether there is no preference. Those expressing no preference will be further asked whether both dentures were satisfactory or unsatisfactory.

Secondary outcome measures

Measured at the end of the secondary impressions, habituation, adjustment and confirmation periods:
1. Comfort, Mobility, Chewing Efficiency using 5-point Likert Scales
2. Oral Health-Related Quality of Life using OHIP-EDENT
3. Patient preference for adjusted dentures
4. Patient perception of comfort, taste and ease of use of each impression material using a 5-point Likert scale
5. Qualitative interviews to gain insight into the impact of oral health status on daily lives

Patient preference for adjusted dentures will be established by asking whether one or other denture is preferred, or whether there is no preference. Those expressing no preference will be further asked whether both dentures were satisfactory or unsatisfactory. Patients will be asked to reflect on the whole process of receiving the final denture (including initial comfort, amount of adjustment needed) when expressing preference.

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Patients of either sex who are edentulous
2. Subject is available for follow up
3. Subject requires replacement complete dentures
4. Subject is able and willing to sign the Informed Consent Form
5. Aged 18 years or over at the time of signing the Informed Consent Form

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Presence of an oral tumour
2. Requirement for an obturator
3. Extreme xerostomia (e.g. Sjogren's Syndrome)
4. Patients who would benefit from selective pressure impressions
5. Known hypersensitivity to silicone or alginate

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Leeds Dental Institute
United Kingdom

Sponsor information


University of Leeds (UK)

Sponsor details

Faculty of Medicine and Health
Level 10
Worsley Building
Clarendon Way
United Kingdom

Sponsor type




Funder type


Funder name

National Institute for Health Research (NIHR) (UK) - Research for Patient Benefit (RfPB) programme (ref: PB-PG-0408-16300)

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

2012 protocol in:
2014 results in:
2014 results in:

Publication citations

  1. Protocol

    Gray JC, Navarro-Coy N, Pavitt SH, Hulme C, Godfrey M, Craddock HL, Brunton PA, Brown S, Dillon S, Dukanovic G, Fernandez C, Wright J, Collier H, Swithenbank S, Lee C, Hyde TP, IMPROVDENT: improving dentures for patient benefit. A crossover randomised clinical trial comparing impression materials for complete dentures., BMC Oral Health, 2012, 12, 37, doi: 10.1186/1472-6831-12-37.

  2. Results

    Hyde TP, Craddock HL, Gray JC, Pavitt SH, Hulme C, Godfrey M, Fernandez C, Navarro-Coy N, Dillon S, Wright J, Brown S, Dukanovic G, Brunton PA, A randomised controlled trial of complete denture impression materials., J Dent, 2014, 42, 8, 895-901, doi: 10.1016/j.jdent.2014.02.005.

  3. Results

    Hulme C, Yu G, Browne C, O'Dwyer J, Craddock H, Brown S, Gray J, Pavitt S, Fernandez C, Godfrey M, Dukanovic G, Brunton P, Hyde TP, Cost-effectiveness of silicone and alginate impressions for complete dentures, J Dent, 2014 , 42, 8, 902-907, doi: 10.1016/j.jdent.2014.03.001.

Additional files

Editorial Notes

24/08/2016: Publication reference added.