Mandibular Distal-extension ProsthesesNCT02178384
Management of Loading Forces Distribution in Mandibular Distal-extension Prostheses
A study testing Altered cast technique, Precision Attachments and Resilient layer in people with Mandibular Distal-extension Prostheses, run by Damascus University at 1 site in Syria.
Trial summary
The two structures that support a mandibular distal extension removable partial denture differ markedly in their visco-elastic response to loading. The difference between the resilience of the residual ridge tissues and the teeth permitted by the periodontal ligament presents a disparity of support that is in contrast… Read more about this study
- Who is it for?
- Ages 35 to 75 years
- Conditions the study is for
- Mandibular Distal-extension Prostheses
- What is being tested?
- Altered cast technique, Precision Attachments and Resilient layer
- Type of treatment
- Medical device, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- 1 siteSyria
- Study dates
- Jun 2014to Oct 2015
- 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 35 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Bilateral distal extension in the mandible (Class I Kennedy's Classification).
- Stable systemic health, including absence of a history of cardiovascular disease.
- No evidence of infection or trauma in the oral region.
- Negative history of syndromes or temporomandibular disorders and parafunction.
Who cannot join
- Other Classes of Kennedy's Classification
- Patients with ages beyond the accepted age range.
Trial locations and contacts
1 site in 1 country.
Syria1 site
Department of Removable Prosthodontics, University of Damascus Dental School
Damascus, Rif-dimashq Governorate, DM20AM18
About this study
Official title: An In-vivo Study to Evaluate Three Methods of Managing the Distribution of Loading Forces in Mandibular Distal-extension Prostheses (Class I Kennedy's Classification)
The two structures that support a mandibular distal extension removable partial denture differ markedly in their visco-elastic response to loading. The difference between the resilience of the residual ridge tissues and the teeth permitted by the periodontal ligament presents a disparity of support that is in contrast to the uniform support accorded a tooth-supported removable partial denture. Hence the denture tends to rotate about its most distal abutments, inducing heavy torsional stresses on alveolar ridges.
Many methods have been used to control this movement, some of them:
Read more
- Implant support on distal extension removable.
- Stress breakers provide a mean of interposing a flexible connection between the tooth-borne retainer portion of removable partial denture and its distally extended tissue-borne segment.
- Altered-cast technique.
- Design development by using mesial indirect retainers rather than distal ones.
The purpose of this study is: (1) to compare bone absorption around abutment teeth nearby the free saddle; (2) denture displacement and pressure on the soft tissue under the denture base of distal extension RPD (Removable Partial Denture) (3) cellular changes in the soft tissue under the denture base of distal extension RPD.
Read the detailed description
Removable partial dentures (RPD) have an essential role in treating partly edentulous. patients with large toothless spaces, or without posterior dental support (Kennedy Class I).
Rehabilitation with Distal-Extension Removable Partial Denture (DERPD) deserves special attention because of the difference in resilience between the remaining mucosa of the edentulous area and the periodontal ligament of the abutment tooth. When occlusal forces affect the bases, the difference in resilience between the mucosa of the edentulous area and the periodontal ligament of the abutment teeth creates a rotating movement whose axis is located on the occlusal rests on the abutment teeth. This may induce horizontal forces and mainly lateral forces upon them, causing inflammation, gingival retraction, increase in dental mobility and distal residual ridge resorption. This movement may cause a reduction in function, discomfort and trauma to the RPD supporting tissues.
MATERIAL AND METHODS:
Patients will be recruited from the Department of Prosthodontics at the University of Damascus Dental School. Thirty patients will be randomly divided into three groups (A, B, and C). A mandibular bilateral distal-extension removable partial denture will be used for patients in all groups. But every group will have its own specific method of distributing loading forces.
In Group A: A Removable partial dentures will be made by using altered-cast technique for free saddle.The investigators will make a primary impression using stock tray. This will be followed by a final impression by individual tray. After metal framework try-in, ridge regions are removed from uncorrected master cast with saw. Then, corrective impression of ridges will be obtained with soft ZOE impression paste. Therefore, a metal framework with associated corrective impression will be repositioned on tooth portion of master cast prior to altering distal-extension bases.
In Group B: Removable partial dentures will be made by using precision attachments which will be located on the last abutment tooth. At first, crowns will be prepared to receive the precision attachment, then these are cemented to their respective abutment teeth. So that a mean of interposing a flexible connection between the tooth-borne retainer portion of a removable partial denture and its distally extended tissue-borne base will be provided.
In Group C: Removable partial dentures will be made by using resilient-layer in the distal extension of the removable partial denture.
- Conditions
- Mandibular Distal-extension Prostheses
- Being tested
- Altered cast technique, Precision Attachments, Resilient layer
- Keywords
- Loading Forces, Removable partial dentures, Bilateral distal extension
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Altered cast techniqueProcedure or surgery
Also called Modified case technique
This techniques deals with the procedures that are employed when constructing the removable partial denture on working casts.
Precision AttachmentsDevice
Also called Joint Attachments
These are minor attachments used to split the loading forces during appliance wear
Resilient layerProcedure or surgery
Also called Flexible layer
This is a layer beneath the appliance which helps in reducing the transmission of loading forces to the underlying soft tissues
| Study group | Role | What they receive |
|---|---|---|
| Altered-cast technique | Experimental | Removable partial dentures will be made using altered-cast technique for free saddles. Receives: Procedure: Altered cast technique |
| Precision attachments | Active comparator | Removable partial dentures will be made using precision attachments which will be located on the distal abutment teeth. Receives: Device: Precision Attachments |
| Resilient layer | Active comparator | Removable partial dentures will be made using a resilient-layer on the distal extension of each appliance. Receives: Procedure: Resilient layer |
What is being measured
The primary outcome is the main question the study is designed to answer.
Soft-tissue vertical displacement (STVD)
Soft tissue vertical displacement will be measured using an impression technique at the free end saddles.
Measured: This variable will be measured at one month, three months and six months following appliance first delivery
Secondary outcomes (2)
Bone absorption of abutment teeth
The amount bone absorption will be measured using apical radiography.
Measured: This variable will be measured at one month, three months and six months following appliance first delivery
Cellular changes of the supporting tissues
A brush will be used to have a smear of the underlying soft tissues. Cellular changes will be evaluated microscopically. The changes observed will be analysed quantitatively.
Measured: This variable will be measured at one month, three months and six months following appliance first delivery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Jun 2014 (estimated)
- Study startJun 2014
- Primary completionJul 2015
- Study completionOct 2015
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (9)Papers the sponsor has linked to this study.
- Other trials for Mandibular Distal-extension ProsthesesStudies 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
- Masking
- None (open label)
- Enrolment
- 30 participants (actual)
Sponsor and investigators
- Lead sponsor
- Damascus University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Fadi Alhaji Jnaid, DDS MSc, Principal investigator, PhD student, Department of Removable Prosthodontics, University of Damascus Dental School, DamascusAlaa' Salloum, DDS MSc PhD, Study director, Senior Lecturer, Removable Prosthodontics Department, University of Damascus Dental School, Damascus
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02178384
- Sponsor's protocol ID
- UDDS-RemPro-01-2014
- Status last verified
- Oct 2015
- First submitted
- 27 Jun 2014
- Last updated
- 5 Oct 2015
- Results posted
- No
- Data monitoring committee
- Yes
Publications
Pellizzer EP, Ferraco R, Tonella BP, Oliveira BJ, Souza FL, Falcon-Antenucci RM. Influence of ridge type on mandibular distal extension removable partial denture. Acta Odontol Latinoam. 2010;23(1):68-73.
PubMed 20645647Aydinlik E, Akay HU. Effect of a resilient layer in a removable partial denture base on stress distribution to the mandible. J Prosthet Dent. 1980 Jul;44(1):17-20. doi: 10.1016/0022-3913(80)90039-6.
PubMed 6991675Kratochvil FJ, Thompson WD, Caputo AA. Photoelastic analysis of stress patterns on teeth and bone with attachment retainers for removable partial dentures. J Prosthet Dent. 1981 Jul;46(1):21-8. doi: 10.1016/0022-3913(81)90129-3.
PubMed 7024514Holmes JB. Influence of impression procedures and occlusal loading on partial denture movement. 1965. J Prosthet Dent. 2001 Oct;86(4):335-41. doi: 10.1067/mpr.2001.119826. No abstract available.
PubMed 11677525Igarashi Y, Ogata A, Kuroiwa A, Wang CH. Stress distribution and abutment tooth mobility of distal-extension removable partial dentures with different retainers: an in vivo study. J Oral Rehabil. 1999 Feb;26(2):111-6. doi: 10.1046/j.1365-2842.1999.00345.x.
PubMed 10080307Leupold RJ, Flinton RJ, Pfeifer DL. Comparison of vertical movement occurring during loading of distal-extension removable partial denture bases made by three impression techniques. J Prosthet Dent. 1992 Aug;68(2):290-3. doi: 10.1016/0022-3913(92)90332-5.
PubMed 1501177Vahidi F. Vertical displacement of distal-extension ridges by different impression techniques. J Prosthet Dent. 1978 Oct;40(4):374-7. doi: 10.1016/0022-3913(78)90115-4.
PubMed 359787Saito M, Miura Y, Notani K, Kawasaki T. Stress distribution of abutments and base displacement with precision attachment- and telescopic crown-retained removable partial dentures. J Oral Rehabil. 2003 May;30(5):482-7. doi: 10.1046/j.1365-2842.2003.01092.x.
PubMed 12752927Tebrock OC, Rohen RM, Fenster RK, Pelleu GB Jr. The effect of various clasping systems on the mobility of abutment teeth for distal-extension removable partial dentures. J Prosthet Dent. 1979 May;41(5):511-6. doi: 10.1016/0022-3913(79)90082-9.
PubMed 374712
Study at a glance
From the registry record, last updated by the sponsor on 5 Oct 2015. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An In-vivo Study to Evaluate Three Methods of Managing the Distribution of Loading Forces in Mandibular Distal-extension Prostheses (Class I Kennedy's Classification)
- ClinicalTrials.gov ID
- NCT02178384
- Acronym / sponsor ID
- UDDS-RemPro-01-2014
- Conditions
- Mandibular Distal-extension Prostheses
- Keywords
- Loading Forces, Removable partial dentures, Bilateral distal extension
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 30 participants (actual)
- Lead sponsor
- Damascus UniversityUniversity, hospital or other
- Study start
- Jun 2014
- Primary completion
- Jul 2015 (actual)
- Study completion
- Oct 2015 (actual)
- First posted
- 30 Jun 2014 (estimated)
- 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.
The two structures that support a mandibular distal extension removable partial denture differ markedly in their visco-elastic response to loading. The difference between the resilience of the residual ridge tissues and the teeth permitted by the periodontal ligament presents a disparity of support that is in contrast to the uniform support accorded a tooth-supported removable partial denture. Hence the denture tends to rotate about its most distal abutments, inducing heavy torsional stresses on alveolar ridges.
Many methods have been used to control this movement, some of them:
- Implant support on distal extension removable.
- Stress breakers provide a mean of interposing a flexible connection between the tooth-borne retainer portion of removable partial denture and its distally extended tissue-borne segment.
- Altered-cast technique.
- Design development by using mesial indirect retainers rather than distal ones.
The purpose of this study is: (1) to compare bone absorption around abutment teeth nearby the free saddle; (2) denture displacement and pressure on the soft tissue under the denture base of distal extension RPD (Removable Partial Denture) (3) cellular changes in the soft tissue under the denture base of distal extension RPD.
Detailed description
Removable partial dentures (RPD) have an essential role in treating partly edentulous. patients with large toothless spaces, or without posterior dental support (Kennedy Class I).
Rehabilitation with Distal-Extension Removable Partial Denture (DERPD) deserves special attention because of the difference in resilience between the remaining mucosa of the edentulous area and the periodontal ligament of the abutment tooth. When occlusal forces affect the bases, the difference in resilience between the mucosa of the edentulous area and the periodontal ligament of the abutment teeth creates a rotating movement whose axis is located on the occlusal rests on the abutment teeth. This may induce horizontal forces and mainly lateral forces upon them, causing inflammation, gingival retraction, increase in dental mobility and distal residual ridge resorption. This movement may cause a reduction in function, discomfort and trauma to the RPD supporting tissues.
MATERIAL AND METHODS:
Patients will be recruited from the Department of Prosthodontics at the University of Damascus Dental School. Thirty patients will be randomly divided into three groups (A, B, and C). A mandibular bilateral distal-extension removable partial denture will be used for patients in all groups. But every group will have its own specific method of distributing loading forces.
In Group A: A Removable partial dentures will be made by using altered-cast technique for free saddle.The investigators will make a primary impression using stock tray. This will be followed by a final impression by individual tray. After metal framework try-in, ridge regions are removed from uncorrected master cast with saw. Then, corrective impression of ridges will be obtained with soft ZOE impression paste. Therefore, a metal framework with associated corrective impression will be repositioned on tooth portion of master cast prior to altering distal-extension bases.
In Group B: Removable partial dentures will be made by using precision attachments which will be located on the last abutment tooth. At first, crowns will be prepared to receive the precision attachment, then these are cemented to their respective abutment teeth. So that a mean of interposing a flexible connection between the tooth-borne retainer portion of a removable partial denture and its distally extended tissue-borne base will be provided.
In Group C: Removable partial dentures will be made by using resilient-layer in the distal extension of the removable partial denture.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Altered-cast technique | Experimental | Procedure: Altered cast techniqueRemovable partial dentures will be made using altered-cast technique for free saddles. |
| Precision attachments | Active comparator | Device: Precision AttachmentsRemovable partial dentures will be made using precision attachments which will be located on the distal abutment teeth. |
| Resilient layer | Active comparator | Procedure: Resilient layerRemovable partial dentures will be made using a resilient-layer on the distal extension of each appliance. |
Who may qualify
- Ages
- 35 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Bilateral distal extension in the mandible (Class I Kennedy's Classification).
- Stable systemic health, including absence of a history of cardiovascular disease.
- No evidence of infection or trauma in the oral region.
- Negative history of syndromes or temporomandibular disorders and parafunction.
Key exclusion criteria (2 listed)
- Other Classes of Kennedy's Classification
- Patients with ages beyond the accepted age range.
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 |
|---|---|---|
| Altered cast techniqueAlso: Modified case techniqueThis techniques deals with the procedures that are employed when constructing the removable partial denture on working casts. | Procedure or surgery | Altered-cast technique |
| Precision AttachmentsAlso: Joint AttachmentsThese are minor attachments used to split the loading forces during appliance wear | Device | Precision attachments |
| Resilient layerAlso: Flexible layerThis is a layer beneath the appliance which helps in reducing the transmission of loading forces to the underlying soft tissues | Procedure or surgery | Resilient layer |
Primary outcome
Soft-tissue vertical displacement (STVD)
Time frame: This variable will be measured at one month, three months and six months following appliance first delivery
Soft tissue vertical displacement will be measured using an impression technique at the free end saddles.
2 secondary outcomes
Bone absorption of abutment teeth
Time frame: This variable will be measured at one month, three months and six months following appliance first delivery
Cellular changes of the supporting tissues
Time frame: This variable will be measured at one month, three months and six months following appliance first delivery
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 5 Oct 2015.
- Background: PubMed 20645647Pellizzer EP, Ferraco R, Tonella BP, Oliveira BJ, Souza FL, Falcon-Antenucci RM. Influence of ridge type on mandibular distal extension removable partial denture. Acta Odontol Latinoam. 2010;23(1):68-73.
- Background: PubMed 6991675Aydinlik E, Akay HU. Effect of a resilient layer in a removable partial denture base on stress distribution to the mandible. J Prosthet Dent. 1980 Jul;44(1):17-20. doi: 10.1016/0022-3913(80)90039-6.
- Background: PubMed 7024514Kratochvil FJ, Thompson WD, Caputo AA. Photoelastic analysis of stress patterns on teeth and bone with attachment retainers for removable partial dentures. J Prosthet Dent. 1981 Jul;46(1):21-8. doi: 10.1016/0022-3913(81)90129-3.
- Background: PubMed 11677525Holmes JB. Influence of impression procedures and occlusal loading on partial denture movement. 1965. J Prosthet Dent. 2001 Oct;86(4):335-41. doi: 10.1067/mpr.2001.119826. No abstract available.
- Background: PubMed 10080307Igarashi Y, Ogata A, Kuroiwa A, Wang CH. Stress distribution and abutment tooth mobility of distal-extension removable partial dentures with different retainers: an in vivo study. J Oral Rehabil. 1999 Feb;26(2):111-6. doi: 10.1046/j.1365-2842.1999.00345.x.
- Background: PubMed 1501177Leupold RJ, Flinton RJ, Pfeifer DL. Comparison of vertical movement occurring during loading of distal-extension removable partial denture bases made by three impression techniques. J Prosthet Dent. 1992 Aug;68(2):290-3. doi: 10.1016/0022-3913(92)90332-5.
- Background: PubMed 359787Vahidi F. Vertical displacement of distal-extension ridges by different impression techniques. J Prosthet Dent. 1978 Oct;40(4):374-7. doi: 10.1016/0022-3913(78)90115-4.
- Background: PubMed 12752927Saito M, Miura Y, Notani K, Kawasaki T. Stress distribution of abutments and base displacement with precision attachment- and telescopic crown-retained removable partial dentures. J Oral Rehabil. 2003 May;30(5):482-7. doi: 10.1046/j.1365-2842.2003.01092.x.
- Background: PubMed 374712Tebrock OC, Rohen RM, Fenster RK, Pelleu GB Jr. The effect of various clasping systems on the mobility of abutment teeth for distal-extension removable partial dentures. J Prosthet Dent. 1979 May;41(5):511-6. doi: 10.1016/0022-3913(79)90082-9.
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.
Fadi Alhaji Jnaid, DDS MSc principal investigator
PhD student, Department of Removable Prosthodontics, University of Damascus Dental School, Damascus
Alaa' Salloum, DDS MSc PhD study director
Senior Lecturer, Removable Prosthodontics Department, University of Damascus Dental School, Damascus
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Altered cast technique, Precision Attachments and Resilient layer in people with Mandibular Distal-extension Prostheses, run by Damascus University at 1 site in Syria.
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 4 inclusion and 2 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 5 Oct 2015. 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 Syria. 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?
Soft-tissue vertical displacement (STVD) (time frame: This variable will be measured at one month, three months and six months following appliance first delivery). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT02178384, which also lists 9 linked publications.
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 5 Oct 2015.