DenturesNCT07583966
Digital VS Conventional Altered Cast Technique for Mandibular Bilateral Distal Extension RPDs
A study testing Digital workflow and Digital altered cast and Conventional Altered Cast Technique in people with Dentures and Mandibular Dimensions, run by Tanta University at 1 site in Egypt.
Trial summary
This study aims to compare outcomes of digitally created altered casts with conventional altered casts in mandibular bilateral distal-extension cases. Read more about this study
- Who is it for?
- Ages 40 to 60 years
- Conditions the study is for
- Dentures, Mandibular Dimensions, Digital
- What is being tested?
- Digital workflow and Digital altered cast and Conventional Altered Cast Technique
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 7 participants
- Where
- 1 siteEgypt
- Study dates
- 30 May 2021to 30 Nov 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 40 to 60 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Patients presented with bilateral, well-formed mandibular distal extension residual ridges covered by keratinized mucosa, with a minimum thickness of 1.5-3 mm .
- Each participant had a sound first or second premolar serving as the terminal abutment, with a crown-to-root ratio of ≥ 1:2.
- Comprised fully or partially dentate maxillary arches, an Angle Class I molar relationship, and adequate interarch space (7-8 mm) to accommodate the prosthesis .
Who cannot join
- The presence of systemic conditions affecting bone metabolism or healing
- pathological conditions in the edentulous area (e.g., residual cysts, retained roots, or severe ridge re-sorption);
- parafunctional habits such as bruxism, clenching, or tongue thrusting
- pro-nounced anatomical undercuts in the lingual mandible or adjacent to abutment teeth that could impede denture fabrication or insertion.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Digital VS Conventional Altered Cast Technique for Mandibular Bilateral Distal Extension Removable Partial Denture
This study aims to compare outcomes of digitally created altered casts with conventional altered casts in mandibular bilateral distal-extension cases.
Read the detailed description
Partially dentate adults represent an increasing proportion of the population, driven by increased life expectancy and a demographic shift from total edentulism toward partial edentulism. Fabrication of removable partial dentures for distal extension edentulous ridges presents significant clinical complexity because the teeth and residual ridge possess fundamentally different degrees of displaceability. Optimum denture support re-quires recording teeth in anatomical form and the mucosa in functional form .
The altered cast impression technique , introduced by Applegate, remains one of the most widely accepted methods for achieving optimal tissue support and accurate denture base positioning relative to tooth abutments . removable partial dentures fabricated using altered cast impression technique demonstrate improved patient comfort and preservation of oral health . However, despite these advantages, debate persists regarding the clinical significance of altered cast impression technique over single-impression techniques .
Recent advances in computer-aided design and computer-aided manufacturing have transformed the removable partial dentures framework, opening new pathways in the fabrication of RPD through additive and subtractive manufacturing . Digital intraoral scanning offers advantages, including reduced dimensional error, improved efficiency, and real-time feedback on impression accuracy and extension [13-16]. However, intraoral scanning techniques are inherently mucostatic and image-based, rendering the recording of functional impression impossible, a limitation acknowledged as necessary for optimal support in distal extension removable partial dentures . Lab scanning of conventionally prepared altered casts pre-pared by traditional methods fails to eliminate inherited errors from cast separation and reassembly.
Recent studies have introduced hybrid digital workflows that combine functional registration of the edentulous ridge with mucostatic scanning of the remaining oral structures in an effort to reproduce conventional clinical procedures while improving efficiency and precision . Most investigations on digital technology in RPD have concentrated on methods for fabricating metal frameworks and evaluating their performance.
This study aims to compare outcomes of digitally created altered casts with conventional altered casts in mandibular bilateral distal-extension cases.
- Conditions
- Dentures, Mandibular Dimensions, Digital
- Being tested
- Digital workflow and Digital altered cast, Conventional Altered Cast Technique
- Keywords
- mandibular, Altered Cast Techniques, Removable Partial Dentures, Digital
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Digital workflow and Digital altered castProcedure or surgery
The RPD design features of fully digitally fabricated RPD illustrated in Figure 2A. Digital selective tissue placement was performed within the same Exocad design project using the free-form scan-data tool, paint and pull feature to apply the principles of selective tissue pressure technique . Using free form mesh editing tools, the buccal shelf area opposing teeth 37 and 47 was identified, and controlled tissue ward displacement of the mucosal surface was simulated while monitoring the magnitude of displacement on sectional views and with digital measurement tools.
Conventional Altered Cast TechniqueProcedure or surgery
For the CA cast technique, one of the SLM frameworks (MF2) was adapted on the stone master cast and used as a functional impression tray (Acrostone Dental Manufacturing, Cairo, Egypt) over the distal extension areas. A selec-tive pressure impression was made according to the traditional altered cast protocol, with the distal saddle areas repoured in dental stone to obtain the CA cast. This CA was then digitized using a desktop scanner (Dove Technologies, Suzhou, China) to produce the CA cast STL. Wax rims were used to verify the jaw relationship, and the maxillary cast was mounted using a facebow transfer on a semi adjustable articulator (A7 Plus, Bio-Art Equi-pamentos Odontológicos Ltda., São Carlos, SP, Brazil), while the mandibular cast was mounted in maximum intercuspation. Semi anatomic acrylic teeth (Acrostone Dental Manufacturing, Cairo, Egypt.) were arranged, and wax try ins were evaluated intraorally in a conventional manner prior to processing.
| Study group | Role | What they receive |
|---|---|---|
| Digital workflow and Digital altered cast group | Experimental | Digital selective tissue placement was performed within the same Exocad design project using the free-form scan-data tool, paint and pull feature to apply the principles of selective tissue pressure technique . Using free form mesh editing tools, the buccal shelf area opposing teeth 37 and 47 was identified, and controlled tissue ward displacement of the mucosal surface was simulated while monitoring the magnitude of displacement on sectional views and with digital measurement tools. Figure 2B, F The modified mandibular dataset was saved as the digitally altered cast STL (DA), which served as the basis for the digital RPD design and subsequent denture base fabrication. Receives: Procedure: Digital workflow and Digital altered cast |
| Conventional workflow and conventional altered cast group | Experimental | For the CA cast technique, one of the SLM frameworks (MF2) was adapted on the stone master cast and used as a functional impression tray (Acrostone Dental Manufacturing, Cairo, Egypt) over the distal extension areas. A selec-tive pressure impression was made according to the traditional altered cast protocol, with the distal saddle areas repoured in dental stone to obtain the CA cast. This CA was then digitized using a desktop scanner (Dove Technologies, Suzhou, China) to produce the CA cast STL. Wax rims were used to verify the jaw relationship, and the maxillary cast was mounted using a facebow transfer on a semi adjustable articulator (A7 Plus, Bio-Art Equi-pamentos Odontológicos Ltda., São Carlos, SP, Brazil), while the mandibular cast was mounted in maximum intercuspation. Receives: Procedure: Conventional Altered Cast Technique |
What is being measured
The primary outcome is the main question the study is designed to answer.
Assessment of the condition of ridge mucosal covering of the Removable Partial Denture constructed out of digitally altered model.
Measured: at 15 days, 3 months and 6 months .
Secondary outcomes (1)
Denture base fit by Pressure Indicating Paste
Measured: one month
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 May 2026
- Study start30 May 2021
- Primary completion30 Nov 2024
- Study completion30 Nov 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for DenturesStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Model Description
- Masking
- None (open label)
- Enrolment
- 7 participants (actual)
Sponsor and investigators
- Lead sponsor
- Tanta University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Kareem Mohammed Reda, Menoufia University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07583966
- Sponsor's protocol ID
- R-RP-5-21-10
- Status last verified
- May 2021
- First submitted
- 1 May 2026
- Last updated
- 13 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 13 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Digital VS Conventional Altered Cast Technique for Mandibular Bilateral Distal Extension Removable Partial Denture
- ClinicalTrials.gov ID
- NCT07583966
- Acronym / sponsor ID
- R-RP-5-21-10
- Conditions
- Dentures, Mandibular Dimensions, Digital
- Keywords
- mandibular, Altered Cast Techniques, Removable Partial Dentures, Digital
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 7 participants (actual)
- Lead sponsor
- Tanta UniversityUniversity, hospital or other
- Study start
- 30 May 2021 (actual)
- Primary completion
- 30 Nov 2024 (actual)
- Study completion
- 30 Nov 2024 (actual)
- First posted
- 13 May 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study aims to compare outcomes of digitally created altered casts with conventional altered casts in mandibular bilateral distal-extension cases.
Detailed description
Partially dentate adults represent an increasing proportion of the population, driven by increased life expectancy and a demographic shift from total edentulism toward partial edentulism. Fabrication of removable partial dentures for distal extension edentulous ridges presents significant clinical complexity because the teeth and residual ridge possess fundamentally different degrees of displaceability. Optimum denture support re-quires recording teeth in anatomical form and the mucosa in functional form .
The altered cast impression technique , introduced by Applegate, remains one of the most widely accepted methods for achieving optimal tissue support and accurate denture base positioning relative to tooth abutments . removable partial dentures fabricated using altered cast impression technique demonstrate improved patient comfort and preservation of oral health . However, despite these advantages, debate persists regarding the clinical significance of altered cast impression technique over single-impression techniques .
Recent advances in computer-aided design and computer-aided manufacturing have transformed the removable partial dentures framework, opening new pathways in the fabrication of RPD through additive and subtractive manufacturing . Digital intraoral scanning offers advantages, including reduced dimensional error, improved efficiency, and real-time feedback on impression accuracy and extension [13-16]. However, intraoral scanning techniques are inherently mucostatic and image-based, rendering the recording of functional impression impossible, a limitation acknowledged as necessary for optimal support in distal extension removable partial dentures . Lab scanning of conventionally prepared altered casts pre-pared by traditional methods fails to eliminate inherited errors from cast separation and reassembly.
Recent studies have introduced hybrid digital workflows that combine functional registration of the edentulous ridge with mucostatic scanning of the remaining oral structures in an effort to reproduce conventional clinical procedures while improving efficiency and precision . Most investigations on digital technology in RPD have concentrated on methods for fabricating metal frameworks and evaluating their performance.
This study aims to compare outcomes of digitally created altered casts with conventional altered casts in mandibular bilateral distal-extension cases.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Model Description
| Arm | Type | Receives |
|---|---|---|
| Digital workflow and Digital altered cast group | Experimental | Procedure: Digital workflow and Digital altered castDigital selective tissue placement was performed within the same Exocad design project using the free-form scan-data tool, paint and pull feature to apply the principles of selective tissue pressure technique . Using free form mesh editing tools, the buccal shelf area opposing teeth 37 and 47 was identified, and controlled tissue ward displacement of the mucosal surface was simulated while monitoring the magnitude of displacement on sectional views and with digital measurement tools. Figure 2B, F The modified mandibular dataset was saved as the digitally altered cast STL (DA), which served as the basis for the digital RPD design and subsequent denture base fabrication. |
| Conventional workflow and conventional altered cast group | Experimental | Procedure: Conventional Altered Cast TechniqueFor the CA cast technique, one of the SLM frameworks (MF2) was adapted on the stone master cast and used as a functional impression tray (Acrostone Dental Manufacturing, Cairo, Egypt) over the distal extension areas. A selec-tive pressure impression was made according to the traditional altered cast protocol, with the distal saddle areas repoured in dental stone to obtain the CA cast. This CA was then digitized using a desktop scanner (Dove Technologies, Suzhou, China) to produce the CA cast STL. Wax rims were used to verify the jaw relationship, and the maxillary cast was mounted using a facebow transfer on a semi adjustable articulator (A7 Plus, Bio-Art Equi-pamentos Odontológicos Ltda., São Carlos, SP, Brazil), while the mandibular cast was mounted in maximum intercuspation. |
Who may qualify
- Ages
- 40 to 60 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Patients presented with bilateral, well-formed mandibular distal extension residual ridges covered by keratinized mucosa, with a minimum thickness of 1.5-3 mm .
- Each participant had a sound first or second premolar serving as the terminal abutment, with a crown-to-root ratio of ≥ 1:2.
- Comprised fully or partially dentate maxillary arches, an Angle Class I molar relationship, and adequate interarch space (7-8 mm) to accommodate the prosthesis .
Key exclusion criteria (4 listed)
- The presence of systemic conditions affecting bone metabolism or healing
- pathological conditions in the edentulous area (e.g., residual cysts, retained roots, or severe ridge re-sorption);
- parafunctional habits such as bruxism, clenching, or tongue thrusting
- pro-nounced anatomical undercuts in the lingual mandible or adjacent to abutment teeth that could impede denture fabrication or insertion.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Digital workflow and Digital altered castThe RPD design features of fully digitally fabricated RPD illustrated in Figure 2A. Digital selective tissue placement was performed within the same Exocad design project using the free-form scan-data tool, paint and pull feature to apply the principles of selective tissue pressure technique . Using free form mesh editing tools, the buccal shelf area opposing teeth 37 and 47 was identified, and controlled tissue ward displacement of the mucosal surface was simulated while monitoring the magnitude of displacement on sectional views and with digital measurement tools. | Procedure or surgery | Digital workflow and Digital altered cast group |
| Conventional Altered Cast TechniqueFor the CA cast technique, one of the SLM frameworks (MF2) was adapted on the stone master cast and used as a functional impression tray (Acrostone Dental Manufacturing, Cairo, Egypt) over the distal extension areas. A selec-tive pressure impression was made according to the traditional altered cast protocol, with the distal saddle areas repoured in dental stone to obtain the CA cast. This CA was then digitized using a desktop scanner (Dove Technologies, Suzhou, China) to produce the CA cast STL. Wax rims were used to verify the jaw relationship, and the maxillary cast was mounted using a facebow transfer on a semi adjustable articulator (A7 Plus, Bio-Art Equi-pamentos Odontológicos Ltda., São Carlos, SP, Brazil), while the mandibular cast was mounted in maximum intercuspation. Semi anatomic acrylic teeth (Acrostone Dental Manufacturing, Cairo, Egypt.) were arranged, and wax try ins were evaluated intraorally in a conventional manner prior to processing. | Procedure or surgery | Conventional workflow and conventional altered cast group |
Primary outcome
Assessment of the condition of ridge mucosal covering of the Removable Partial Denture constructed out of digitally altered model.
Time frame: at 15 days, 3 months and 6 months .
1 secondary outcome
Denture base fit by Pressure Indicating Paste
Time frame: one month
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 May 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Digital workflow and Digital altered cast and Conventional Altered Cast Technique in people with Dentures and Mandibular Dimensions, run by Tanta University at 1 site in Egypt.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 13 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Egypt. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Assessment of the condition of ridge mucosal covering of the Removable Partial Denture constructed out of digitally altered model. (time frame: at 15 days, 3 months and 6 months .). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 May 2026.