Patient-Related Outcomes of Digital and Conventional Removable Partial Dentures..A Crossover Randomised Clinical Trial
Phase: NA
Conditions: Partially Edentulous Patients
Sponsor: King Abdulaziz University

   
 
 
Comparison of Patient Satisfaction Between Conventional and Digital Removable 
Partial Dentures 
 
NCT Number NCT07228988 
10/04/2025 
 
Research Proposal 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
Abstract 
Removable partial dentures (RPDs) remain a valid and widely used approach for the 
rehabilitation of partially edentulous patients. Recent advances in digital technologies 
using additive manufacturing (3D-printing), subtractive manufacturing (milling), and the 
development of new materials such as polyetheretherketone (PEEK) are currently used for 
the construction of RPDs. This study aims to compare patient satisfaction between 
conventional cast Co–Cr, 3D-printed Co–Cr, and PEEK RPDs using a within-subject 
randomized crossover clinical design. Each participant will use each RPD type for one 
month, with a one-week washout period after each type. Patient satisfaction will be 
assessed using the Visual Analogue Grade (VAG) scale, and the Oral Health Related 
Quality of Life (OHRQoL) will be evaluated using Oral Health Impact Profile OHIP-14 
questionnaire. Data will be analyzed using repeated-measures ANOVA or the Friedman 
test. The null hypothesis of the study that digital techniques will outperform the 
conventional fabrication method. 
Introduction  
Removable partial dentures (RPDs) continue to be a treatment modality for partially 
edentulous patients especially in distal extension and reduced dentition cases. 
Traditionally, Cobalt–Chromium (Co–Cr) frameworks fabricated using the conventional 
Lost-Wax Technique (LWT) have been the standard method of fabrication due to its known 
advantages such as: their strength, rigidity, thermal conductivity, and biocompatibility. 
However, cast frameworks may present drawbacks such as: inaccuracies, poor esthetics, 
and metal taste. Advances in digital technology have introduced 3D-printed Co–Cr 
frameworks, which offer enhanced accuracy and reproducibility. Additionally, PEEK has 
emerged as a promising nonmetallic alternative characterized by its lightweight, favorable 
mechanical properties, and esthetics. 
However, there is limited evidence comparing patient satisfaction and OHRQoL among 
patients wearing these three types of RPDs under identical clinical conditions.  
Aim of the Study 
To compare patient satisfaction among conventional cast Co–Cr, 3D-printed Co–Cr, and 
PEEK RPDs, and the impact of these denture fabrication techniques on the OHRQoL. 
Materials and Methods 
The study was approved by the Ethics Committee of the Faculty of Dentistry, King 
Abdulaziz University. All treatment procedures were discussed in details with the selected 
patients. There were no risks at all, and patients could benefit from having all the three 
types of prostheses with no fees. Written informed consent were obtained from all 

participants before inclusion. Participants had the right to withdraw at any stage without 
any consequences. 
Study Design 
A within-subject randomized crossover clinical trial was conducted at the Faculty of 
Dentistry, King Abdulaziz University.  
Each participant received three RPDs (conventional cast Co–Cr, 3D-printed Co–Cr, and 
PEEK) fabricated to the same RPD design. Every patient used each denture type for one 
month, with a one-week washout period between each trial phase. 
 
Sample size: 
Sample size calculation was based upon detecting a moderate effect size (f = 0.25) 
using repeated measures ANOVA test. Using 80% power and α = 0.05, the minimum 
estimated sample size was 28 participants. Sample size was increased to a total of 34 
participants to compensate for drop-out. Sample size calculation was performed using 
G*Power Version 3.1.9.2. 
 
Inclusion and Exclusion Criteria 
Participants are partially edentulous patients having mandibular Kennedy Class I arches 
with the last abutment is the first or the second premolars bilaterally. Participants should 
have good oral hygiene, healthy mucosa, and absence of systemic diseases or medications 
that could affect the oral tissues. Exclusion criteria include periodontal disease, poor 
compliance, or history of temporomandibular disorders. 
Randomization and Sequence Allocation 
The sequence of RPD type allocation was randomized using a computer-generated 
randomization list (using random.org website). Patients received the three prostheses in 
different sequences to minimize order effects. 
Outcome Measures 
Patient satisfaction was assessed using the Visual Analogue Grade (VAG) scale (0–100 
mm) and the OHRQoL was measured using OHIP-14 questionnaire. The VAG patient 
satisfaction domains such as: comfort, esthetics, speech, and mastication, while OHIP-14 
consists of 7 domains each include 2 questions. Finally, each patient have chosen the most 
preferred denture after the completion of all the treatment phases. 
 
 

 
 
 
1-Visual Analogue Grade (VAG) scale (0–100 mm), higher score indicates a better outcome 
Domain 
Description (summary) 
Retention 
How well the denture stays in place 
during function. 
Stability 
Movement of the denture during chewing 
or speaking. 
Comfort 
Overall feeling of comfort while wearing 
the denture. 
Aesthetics 
Appearance and natural look of the 
denture. 
Speech 
Ease and clarity of speaking with the 
denture. 
Mastication 
Ability to chew different types of food 
effectively. 
Ease of Cleaning 
How easy it is to clean and maintain the 
denture. 
Overall Satisfaction 
General satisfaction with the denture 
experience. 
 
2-Oral Health Related Quality of Life using OHIP-14 :At the end of each denture 
use (after one month) 
Responses are rated on a 5 point Likert scale 0=never 1= hardly ever 2=occasionally 
3=fairly often  4=very often, higher scores indicate a worse oral health quality of life 
Domain 
Question 

Functional Limitation 
1. Have you had trouble pronouncing any 
words because of problems with your 
teeth, mouth, or dentures? 
2. Have you felt that your sense of taste 
has worsened because of problems with 
your teeth, mouth, or dentures? 
Physical Pain 
3. Have you had painful aching in your 
mouth? 
4. Have you found it uncomfortable to eat 
any foods because of problems with your 
teeth, mouth, or dentures? 
Psychological Discomfort 
5. Have you been self-conscious because 
of your teeth, mouth, or dentures? 
6. Have you felt tense because of 
problems with your teeth, mouth, or 
dentures? 
Physical Disability 
7. Has your diet been unsatisfactory 
because of problems with your teeth, 
mouth, or dentures? 
8. Have you had to interrupt meals 
because of problems with your teeth, 
mouth, or dentures? 
Psychological Disability 
9. Have you found it difficult to relax 
because of problems with your teeth, 
mouth, or dentures? 
10. Have you been a bit embarrassed 
because of problems with your teeth, 
mouth, or dentures? 
Social Disability 
11. Have you been a bit irritable with 
other people because of problems with 
your teeth, mouth, or dentures? 
12. Have you had difficulty doing your 
usual jobs because of problems with your 
teeth, mouth, or dentures? 
Handicap 
13. Have you felt that life in general was 
less satisfying because of problems with 

your teeth, mouth, or dentures? 
14. Have you been totally unable to 
function because of problems with your 
teeth, mouth, or dentures? 
 
 
3-Overall patient preference 
After using all the three dentures, by the end of the 3rd phase  
Single forced choice question at the end of the three phases: 
Which denture did you prefer overall? 
o Conventional cast Co-Cr 
o 3D- printed Co-Cr 
o PEEK 
Statistical Analysis 
Data will be analyzed using SPSS software. Descriptive statistics will summarize mean 
and standard deviation for each variable. Normality will be checked using the Shapiro–
Wilk test. Depending on data distribution, repeated-measures ANOVA or Friedman tests 
will be used. The significance level will be set at p < 0.05. 
 
References 
1. Al-Harbi FA, et al. Comparison of patient satisfaction with PEEK and Co–Cr 
removable partial dentures. J Prosthet Dent. 2020;123(5):780–787. 
2. Revilla-León M, et al. Metal additive manufacturing technologies for dental 
frameworks: A review. J Prosthet Dent. 2019;122(5):521–528. 
3. Stawarczyk B, et al. Polyetheretherketone (PEEK) in dentistry—advantages and 
limitations. Dent Mater J. 2021;40(2):206–213. 
4. Koller M, et al. Patient-based outcomes with removable partial dentures fabricated 
using CAD/CAM technologies. Int J Prosthodont. 2022;35(4):423–430. 
5. Locker D, et al. Measuring oral health-related quality of life: OHIP-14 validation. 
Community Dent Oral Epidemiol. 2002;30(6):438–443.