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

Plain English Summary

Background and study aims
When people start wearing dentures for the first time, it can affect the way they speak. They may find that their voice has changed and they may have difficulties speaking for a short while. Possible reasons for this include the tongue not being able to get into the correct position or the denture itself being too thick or thin in certain areas. This study looks at the effect of different types of material of complete denture bases and different types of teeth on a person’s short-term phonetics (I.e. the way they sound when they speak). Complete dentures affect speech sounds by changing the shape of the mouth (oral cavity dimensions) and structure (morphology). Upper incisors (front upper teeth) and different thickness of the dentures palatal plate in different positions have been reported as having an effect on the dimensions of the oral cavity. The impact of these factors on sounds, virtual period of distinct sounds in a word and the patient’s variation with the dentures were examined. Speech making has a major consequence on patients’ overall pleasure with the dentures and make them more likely to accept them. The changes in speech that often happen after a person starts to wear dentures are often temporary, but are still a source of worry for many. In addition, there is a lack of guidelines on designing dentures with best phonetic success.

Who can participate?
Men aged at least 55 years without teeth.

What does the study involve?
Participants are split into two batches with three groups in one batch and two groups in the other. Allocation to a particular group is done randomly. The participants in the first batch are given dentures made with one of three different denture base materials (flexible acrylic resin, heat cure acrylic resin, or chrome cobalt metallic base). The two groups in the second batch are given one of two different teeth types for their dentures: acrylic teeth and porcelain teeth. Each participants speech is then analysed by measuring their phonetics immediately after being given their dentures, then again 3 weeks and ten weeks later.

What are the possible benefits and risks of participating?
Not provided at time of registration.

Where is the study run from?
Al-Azhar University-Assiut Branch Dental Clinic (Egypt)

When is the study starting and how long is it expected to run for?
January 2015 to April 2015

Who is funding the study?
Albaha University (Saudi Arabia)

Who is the main contact?
Professor Khalid Arafa

Trial website

Contact information



Primary contact

Prof Khalid Arafa


Contact details

Faculty of Applied Medical Sciences
Albaha University
P.O. Box: 7273-Unit No.: 2
65536 - 3047
Saudi Arabia

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Effect of different complete dentures base materials and teeth types on short-term phonetics


Study hypothesis

Different complete dentures base materials and teeth types affect on short-term phonetics

Ethics approval

Dental Health Department of the Faculty of Applied Medical Sciences, Albaha University.

Study design

A parallel design experimental study.

Primary study design


Secondary study design

Randomised parallel trial

Trial setting


Trial type


Patient information sheet

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


Dentures and phonetics


The patients enrolled in the study (n=50) were divided into two main batches (three groups in batch one and two groups in batch two), with a total of ten patients in each group. The patients were randomly assigned into groups. The three groups in the first batch received three different denture base materials for the constructed palatal plate and rouge area of the complete dentures, (flexible acrylic resin, heat cure acrylic resin, and chrome cobalt metallic base). Another batch (twenty patients) divided into two groups received different teeth types: acrylic teeth and porcelain teeth.

Intervention type



Drug names

Primary outcome measure

The evaluation of the speech quality was made by measuring the phonetics. The patients were connected to a spectrogram and were asked to verbalize Arabic pronunciation letters (ص، ض، ع،غ). The mean of the sound levels was calculated for each patient, and subsequently tabulated and analyzed. The evaluation was made immediately following denture insertion: three weeks, and ten weeks following the insertion of dentures by a computerized speech lab (spectrogram). This measurement protocol was implemented for two batches. The level of sound in patients with complete dentures made from different base materials or different teeth was assessed via a spectrogram. (it was measured at insertion, 3 weeks later and after 10 weeks)

Secondary outcome measures


Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Male, aged 55 years or older
2. Completely edentulous
3. Normal occlusion class one
4. Free from disabilities or chronic conditions, such as diabetes

Participant type


Age group




Target number of participants


Total final enrolment


Participant exclusion criteria

1. Diabetic patients
2. Participants that are partially edentulous,
3. Participants that have neglected oral hygiene

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

Al-Azhar University-Assiut Branch Dental Clinic
Faculty of Dentistry

Sponsor information


Albaha University

Sponsor details

Saudi Arabia

Sponsor type




Funder type


Funder name

Albaha University (Saudi Arabia)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Intention to publish date

Participant level data

Not expected to be available

Basic results (scientific)

Publication list

2016 results in (added 24/07/2020)

Publication citations

Additional files

Editorial Notes

24/07/2020: Publication reference and total final enrolment number added. 20/10/2015: Trial participating centre has been changed from Deaf and Dumb Service Center to Al-Azhar University-Assiut Branch Dental Clinic.