Edentulism, Edentulism Complete
Conditions
Keywords
Edentulism, Complete dentures, Digital dentistry, 3D printing, CAD/CAM, Occlusal wear, Denture teeth, Randomized controlled trial
Brief summary
This randomized controlled trial evaluates the occlusal wear of denture teeth fabricated using three digital workflows: 3D-printed denture teeth, CAD/CAM-milled double cross-linked denture teeth, and prefabricated denture teeth. Occlusal wear will be assessed over 24 months using digital superimposition techniques. The study aims to determine whether 3D-printed denture teeth demonstrate superior wear resistance compared to CAD/CAM-milled denture teeth.
Detailed description
This is a single-center, prospective, randomized, controlled, double-blind clinical investigation comparing three digitally fabricated complete removable dental prosthesis workflows in edentulous patients. The study will be conducted at the University Clinics of Dental Medicine, University of Geneva. The study includes adult patients who are completely edentulous in the maxillary and mandibular arches and require new complete removable dental prostheses. Participants may be rehabilitated with either a conventional mandibular complete denture or a mandibular implant overdenture supported by clinically stable implants. This inclusion strategy is intended to improve recruitment feasibility and reflect real-world clinical practice. Mandibular prosthetic status at baseline will be used as a stratification factor during randomization and will be accounted for in the statistical analysis. A total of 48 participants\*\* will be randomized in a 1:1:1 allocation ratio to one of three treatment groups: fully 3D-printed complete dentures with printed denture base and printed denture teeth; CAD/CAM-milled complete dentures with milled double cross-linked denture teeth; or CAD/CAM-milled complete dentures with prefabricated denture teeth, serving as a clinical benchmark group. The primary objective is to compare occlusal wear performance of denture teeth between the fabrication workflows. The primary confirmatory comparison will be conducted between the fully 3D-printed workflow and the CAD/CAM-milled double cross-linked workflow. Occlusal wear will be assessed by three-dimensional digital superimposition of intraoral scans acquired at baseline and follow-up visits. The primary endpoint is the average negative deviation of occlusal surfaces at 24 months, representing material loss over time. \> Secondary outcomes include root mean square surface deviation, patient-reported outcomes assessed with the Oral Health Impact Profile for Edentulous Patients and the Denture Satisfaction Index, chewing efficiency, bite force, prosthetic retention, color stability, prosthesis-related costs, maintenance interventions, and prosthetic complications. These outcomes will be assessed according to the study schedule at baseline and during follow-up visits at 12, 24, and 60 months. Participants and outcome assessors will be blinded to denture fabrication workflow and denture tooth material allocation. Prostheses will be labeled using anonymized codes, and digital files used for wear analysis will be anonymized using participant study ID and time point. Treating clinicians and laboratory personnel will not be blinded due to the nature of the intervention, but they will not be involved in blinded outcome assessment. All prostheses will be fabricated according to standardized clinical and laboratory procedures using CE-marked medical devices and materials according to the manufacturers' instructions for use. The prosthetic treatment phase will include clinical evaluation, impressions, intermaxillary records, prototype try-in, and delivery of the final prostheses. Follow-up assessments will be performed after prosthesis delivery to evaluate clinical, functional, patient-reported, material-related, and maintenance outcomes.
Interventions
DEVICECAD/CAM-Milled Denture Base with Milled Denture Teeth
Complete removable dental prostheses fabricated using a digital workflow with CAD/CAM milling. Both the denture base and denture teeth are produced by subtractive manufacturing from pre-polymerized resin materials, including double cross-linked denture teeth, and assembled.
DEVICECAD/CAM-Milled Denture Base with Prefabricated Denture Teeth
Complete removable dental prostheses fabricated using a digital workflow with CAD/CAM-milled denture bases combined with conventionally manufactured prefabricated denture teeth. The prefabricated teeth are selected and positioned digitally or manually and then bonded to the milled denture base.
DEVICE3D-printed denture base and teeth
Description Complete removable dental prostheses fabricated using a fully digital workflow in which both the denture base and denture teeth are produced by 3D printing using light-curing resin materials. The prostheses are designed digitally and manufactured additively.
Sponsors
Najla Chebib
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Outcomes Assessor)
Masking description
This study is double-blind. Participants and outcome assessors are blinded to the allocation of denture tooth material. All prostheses are fabricated externally and labeled using anonymized codes to conceal the fabrication method aand type of denture teeth used. The external appearance of the prostheses is standardized to prevent identification of the material. Digital files used for outcome assessment (wear analysis) are anonymized and coded by study ID and timepoint, ensuring that outcome assessors remain blinded throughout the analysis.
Intervention model description
Participants are randomized in a 1:1:1 ratio to one of three parallel groups receiving complete dentures fabricated with different denture tooth materials (3D-printed, CAD/CAM-milled, or prefabricated).
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Written informed consent provided by the participant * Age ≥ 18 years * Fully edentulous maxilla and mandible requiring rehabilitation with new complete removable dental prostheses * Patients with or without mandibular implants (implant overdenture or conventional denture) * Clinical indication for fabrication of new maxillary and mandibular complete removable dental prostheses * Currently wearing complete dentures, or a maxillary denture combined with a mandibular denture or overdenture * Ability and willingness to attend all scheduled follow-up visits for the duration of the study
Exclusion criteria
* Contraindications to the medical devices used, e.g. known hypersensitivity or allergy; * Known or suspected non-compliance, drug or alcohol abuse; Inability to follow the procedures of the investigation; * Enrolment of the investigator, his/her family members, employees and other dependent persons; * Reported severe bruxism or clenching habits, identified through patient interview and clinical examination, including self-reported grinding or clenching, partner reports, morning jaw discomfort, and other signs of parafunctional activity; * Width of the edentulous maxilla \>80 mm; * Width of the edentulous mandible \>80 mm; Vertical prosthetic space \<38 mm (maxilla or mandible); * Depression: Geriatric Depression Scale \>9; * Xerostomia: UFR ≤ 0.2ml/2min; * Dementia: Clock-Drawing Test ≤5; * Active peri-implant disease or instability of the two mandibular implants at baseline when implants are present; * Presence of an implant-retained prosthesis in the maxilla; * Planned implant-related surgical intervention during the study period.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Occlusal Wear of Denture Teeth | from baseline to 24 month | Occlusal wear of denture teeth will be assessed using three-dimensional digital superimposition of intraoral scans acquired at baseline and follow-up visits. Wear will be quantified as the average negative deviation (-AVG) between superimposed surfaces, expressed in micrometers (µm), representing material loss over time. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Surface Deviation (Root Mean Square, RMS) | from baseline to 12, 24 and 60 months | Surface deviation will be quantified using root mean square (RMS) values derived from three-dimensional superimposition of intraoral scans, providing a global measure of surface change. |
| Maximum Bite Force | at Baseline, 12, 24, and 60 months | Maximum bite force will be measured using a digital bite force device, expressed in Newtons (N). |
| Chewing Efficiency | at baseline, 12, 24, and 60 months | Chewing efficiency will be assessed using a standardized two-color mixing test, quantified as variance of hue (VOH). |
| Oral Health-Related Quality of Life | at baseline, 12, 24, 60 months | Patient-reported oral health-related quality of life will be assessed using the OHIP-EDENT questionnaire. The OHIP-EDENT questionnaire consists of 19 items assessing oral health-related quality of life in edentulous patients. Each item is scored on a 5-point Likert scale (0 = never to 4 = very often), with a total score ranging from 0 to 76. Higher scores indicate worse oral health-related quality of life. |
| Denture Satisfaction | at baseline, 12, 24, and 60 months | Patient satisfaction with dentures will be assessed using a validated questionnaire. Denture satisfaction will be assessed using a Visual Analog Scale (VAS) ranging from 0 to 10, where 0 indicates no satisfaction and 10 indicates maximum satisfaction. Higher scores reflect greater patient satisfaction with the prosthesis. |
| Denture Retention | at baseline | Retention of the maxillary denture bases will be assessed by measuring the force required to dislodge the prosthetic base from the denture-bearing tissues. A digital dynamometer will be attached to a standardized central hook incorporated into the test base. The base will be seated intraorally, and a controlled vertical traction force will be applied until dislodgement occurs. The maximum force required to dislodge the base will be recorded in Newtons (N). Higher values indicate greater denture base retention. |
| Color Stability | at baseline, 12, 24, and 60 months | Color changes of denture teeth will be assessed using colorimetric measurements and expressed as ΔE values. |
| Total prosthesis fabrication cost | at baseline, | Costs related to prosthesis fabrication will be recorded for each study group. This will include initial laboratory fabrication costs in swiss francs CHF per participant. |
| Number of Prosthetic Maintenance Visits | from baseline to 12, 24, and 60 months | The number of additional prosthesis-related maintenance visits required after prosthesis delivery will be recorded for each participant. Maintenance visits may include visits for adjustment, repair, relining, or management of prosthetic complications. it will be measured as the number of prosthetic maintenance visits per participant (NPMV) and cost associated to each visit in Swiss francs (CHF) per participant. |
| Incidence of Prosthetic Complications | From baseline to 12 months, 24 months, and 60 months | Prosthetic complications will be recorded as the number and percentage of participants experiencing at least one clinically relevant complication during follow-up. Complications may include denture base fracture, tooth detachment, prosthesis damage, loss of retention requiring intervention, relining, repair, or prosthesis remake/replacement. Each event will be documented by type and timing. |
Contacts
CONTACTNajla Chebib, PD Dr med dent
CONTACTAlessio Casucci, Dr Phd
PRINCIPAL_INVESTIGATORNajla Chebib, Dr med dent
University of Geneva, Switzerland
PRINCIPAL_INVESTIGATORAlessio Casucci
University of Geneva, Switzerland
Outcome results
None listed