Patients' Satisfaction and Clinical Investigation of Removable Partial Denture Anchorage With Extracoronal Adhesive Attachments in Comparison With Clasp-retained Partial Dentures

NCT ID: NCT07160660

Last Updated: 2025-09-12

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Total Enrollment: 250 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2025-10-01
• Study Completion Date: 2026-04-01

Brief Summary

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.

Conditions

Extracoronal Adhesive Attachment; Clasp-retained Partial Dentures; Patients Satisfaction With Removable Dental Prostheses

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: RETROSPECTIVE

Study Groups

Patients with extracoronal adhesive attachments as retentive elements of RPD (group A)

RDP = removable dental prostheses

Patients' satisfaction and clinical investigation of removable partial denture anchorage with extracoronal adhesive attachments

Intervention Type: 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 with clasps as retentive elements of RPD (group B)

RDP = removable dental prostheses

Patients' satisfaction and clinical investigation of removable partial denture anchorage with conventional clasps

Intervention Type: 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).

Interventions

Patients' satisfaction and clinical investigation of removable partial denture anchorage with extracoronal adhesive attachments

• 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).

Intervention Type: OTHER

Patients' satisfaction and clinical investigation of removable partial denture anchorage with conventional clasps

• 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).

Intervention Type: OTHER

Eligibility Criteria

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.

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

University of Basel

OTHER

Sponsor Role: lead

Responsible Party

Florence Auderset

Member of Research Group of the Department of Clinical Research, Principal Investigator, Dr. med. dent.

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Nicola Zitzmann, Prof. Dr. med. dent. PhD

Role: STUDY_CHAIR

University of Basel

Locations

Universitäres Zentrum für Zahnmedizin Basel - Klinik für Rekonstruktive Zahnmedizin

Basel, Basel, Switzerland

Countries

Switzerland

Central Contacts

Florence Auderset, Dr. med. dent.

Role: CONTACT

florence.auderset@unibas.ch

+41 79 789 87 04

Facility Contacts

Florence Auderset, Dr. med. dent.

Role: primary

florence.auderset@unibas.ch

+41 79 789 87 04

References

Schaffer H. [Clinical results of partial denture anchorage using extracoronal bonded attachments]. Dtsch Zahnarztl Z. 1990 Jun;45(6):326-8. German.

Reference Type: BACKGROUND

PMID: 2269117 (View on PubMed)

Besimo C, Gachter M, Jahn M, Hassell T. Clinical performance of resin-bonded fixed partial dentures and extracoronal attachments for removable prostheses. J Prosthet Dent. 1997 Nov;78(5):465-71. doi: 10.1016/s0022-3913(97)70061-1.

Reference Type: BACKGROUND

PMID: 9399188 (View on PubMed)

Dula LJ, Kelmendi TZ, Shala K, Staka G, Pustina-Krasniqi T, Kosumi S. Attachment-Retained versus Clasp-Retained Removable Partial Dentures: Effects of Retention on Patient Satisfaction. Eur J Dent. 2025 Jul;19(3):823-834. doi: 10.1055/s-0044-1795122. Epub 2024 Dec 30.

Reference Type: BACKGROUND

PMID: 39750515 (View on PubMed)

Kraljevic I, Glenz F, Jordi C, Zimmermann SD, Joda T, Zitzmann NU. Long-Term Observation of Post Copings Retaining Overdenture Prostheses. Int J Prosthodont. 2020 Mar/Apr;33(2):169-175. doi: 10.11607/ijp.6629.

Reference Type: BACKGROUND

PMID: 32069341 (View on PubMed)

Zitzmann NU, Rohner U, Weiger R, Krastl G. When to choose which retention element to use for removable dental prostheses. Int J Prosthodont. 2009 Mar-Apr;22(2):161-7.

Reference Type: BACKGROUND

PMID: 19418863 (View on PubMed)

Brandt S, Winter A, Lauer HC, Romanos G. Retrospective clinical study of 842 clasp-retained removable partial dentures with a metal framework: survival, maintenance needs, and biologic findings. Quintessence Int. 2024 Oct 24;55(9):704-711. doi: 10.3290/j.qi.b5566187.

Reference Type: BACKGROUND

PMID: 38985439 (View on PubMed)

Garling A, Krummel A, Kern M. Outcomes of resin-bonded attachments for removable dental prostheses. J Prosthodont Res. 2024 Jan 16;68(1):100-104. doi: 10.2186/jpr.JPR_D_22_00306. Epub 2023 May 20.

Reference Type: BACKGROUND

PMID: 37211411 (View on PubMed)

Other Identifiers

PSCI2025

Identifier Type: -

Identifier Source: org_study_id