Universitäres Zentrum für Zahnmedizin Basel - Klinik für Rekonstruktive Zahnmedizin
Basel, 4058, Switzerland
Enrolling by Invitation
NCT Number: NCT07160660
Patients' Satisfaction and Clinical Investigation of Removable Partial Denture Anchorage With Extracoronal Adhesive Attachments in Comparison With Clasp-retained Partial Dentures
Removable partial dentures (RPD) are a well-established treatment option for the prosthetic rehabilitation of partially edentulous patients. They are retained at the remaining natural teeth by clasps to provide functional stability. As an alternative to clasps extacoronal adhesive attachments are fixed to the abutment teeth using adhesive cementation techniques. These adhesive attachments improve retention and stability of the prostheses and are indicated when the patient requires a non-visible retention element and healthy coronal tooth structure is available as a prerequisite. In clinical practice, extracoronal adhesive attachments offer a minimally invasive and aesthetic anchoring alternative of removable dental prostheses associated with higher costs compared to a common clasp retention. As a result, adhesive attachments are relatively rarely used and are technically sensitive both in the clinical realisation and in terms of the dental technology. Hence, limited scientific data are available regarding their long-term clinical behaviour, but no data is available about patients' satisfaction with such extracoronal adhesive attachments.
This research project aims to investigate patients' satisfaction with extracoronal adhesive attachments (group A) of removable dental prostheses in comparison to clasps (group B), and to investigate the short- and long-term clinical performance of both treatment options.
This is a non-interventional observational study. Only routine clinical examinations are performed. No additional risks or burdens arise for participants. All measures fall under minimal risk A according to ClinO, Art. 61. Overall risk: Minimal. No invasive procedures or biological sampling. Ethical and legal standards are fully met.
Sex and gender dimensions are not relevant to the topic of the study as the population is determined by patients treated since 2001 and cannot be influenced by the study design.
Enrolling by Invitation
Interested in participating?
Request InfoKey information
Conditions
Age range
18 year and older
Sex eligibility
All sexes
Study type
Observational
Primary location
Who can participate
Healthy volunteers accepted: No
Only the study team can determine whether someone qualifies for participation.
Inclusion criteria
- Signed informed consent.
- Patients with at least one extracoronal adhesive attachment for anchoring an RPD and patients with clasp-retained RPD during a 25-year period (2001 - 2025) at the Department for Reconstructive Dentistry or the affiliated student course.
- The attachment or clasp must have been in place for a minimum of six months at the time of clinical follow-up.
- Sufficient availability of medical/dental records
- Age ≥18 years at time of initial treatment.
- Ability to attend a clinical follow-up appointment.
Exclusion criteria
- Patients unable to provide informed consent.
- Incomplete or missing documentation of the prosthetic treatment.
- Attachments or clasps inserted less than six months ago.
- Inability to attend the follow-up appointment or language barriers preventing study understanding.
Treatment and study plan
Patients' satisfaction and clinical investigation of removable partial denture anchorage with extracoronal adhesive attachments
Other- Completion of a questionnaire by the participant, including patient satisfaction on VAS (visual analogue scale) and prostheses usability, clinical examination of the remaining dentition, the abutment teeth of the extracoronal adhesive attachment and the RPD.
- Evaluation of the attachment's condition, retention, and any signs of biological or technical complications.
- Collection of relevant medical and dental history from patients' records (consent provided).
Patients' satisfaction and clinical investigation of removable partial denture anchorage with conventional clasps
Other- Completion of a questionnaire by the participant, including patient satisfaction on VAS (visual analogue scale) and prostheses usability, clinical examination of the remaining dentition, the abutment teeth of the clasps and the RPD.
- Evaluation of the clasps' condition, retention, and any signs of biological or technical complications.
- Collection of relevant medical and dental history from patients' records (consent provided).
Primary outcomes
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Patients' satisfaction with extracoronal adhesive attachments (group A) compared to conventional clasp-retained prostheses (group B) on a visual analogue scale (VAS)
Time frame: From 2001 to present (RDP with retention element has to be in place for at least 6 months)
The primary objective of this study is to assess patients' satisfaction with extracoronal adhesive attachments (group A) compared to conventional clasp-retained prostheses (group B) on a visual analogue scale (VAS).
The scale ranges from 0 - 100. A lower score means a worse outcome (satisfaction low) and a higher score a better outcome (satisfaction high). The participants will be instructed and asked to mark a point on the scale according to their satisfaction with the extracoronal adhesive attachment or the clasp-retained prostheses.
Secondary outcomes
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Occurrence of biological complications associated with the use of extracoronal adhesive attachments and conventional clasps
Time frame: From 2001 to present (RDP with retention element has to be in place for at least 6 months)
At the recall appointment, a clinical examination of the remaining dentition and the prostheses will be performed. The primary assessment will determine whether the abutment tooth with the attachment/clasp remains in situ. The secondary assessment includes a clinical evaluation of the periodontal and endodontic conditions. All biological complications such as caries lesions, tooth fractures, periodontal attachment loss, and endodontic pathologies of the abutment teeth will be reported in a standardized dental record.
If consent is given, relevant information from the existing dental records will also be extracted for analysis.
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Occurrence of technical complications associated with the use of extracoronal adhesive attachments and conventional clasps
Time frame: From 2001 to present (RDP with retention element has to be in place for at least 6 months)
At the recall appointment, a clinical examination of the remaining dentition and the prostheses will be performed. The assessment includes a clinical evaluation of the technical condition of the attachment/clasp and the RDP, such as comprise loss of retention between the extracoronal adhesive attachment and the corresponding matrice, loss of the matrice, debonding of the attachment, fracture of the attachment or clasps, deactivation of the clasps, fracture of the removable dental prostheses. The findings will be reported in a standardized dental record.
If consent is given, relevant information from the dental records will also be extracted for analysis.
Sponsors and collaborators
Lead sponsor
University of Basel
Other
Registry information
Important dates
- Study start
- 2026
- Primary completion
- 2026
- Study completion
- 2026
- First posted
- Sep 8, 2025
- Registry last updated
- Mar 31, 2026
OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.
View the official ClinicalTrials.gov record (opens in a new tab)This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.