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NCT Number: NCT07639112

Masticatory Efficiency, Bite Force, and Patient-Reported Outcomes in Patients Rehabilitated With Complete and Partial Dentures Supported by Teeth, Mini-Implants, or Conventional Implants

This study aims to evaluate masticatory efficiency, bite force, and patient-reported outcomes in edentulous and partially edentulous patients rehabilitated with different removable prosthodontic treatment modalities. The study includes both cross-sectional and longitudinal components. The cross-sectional component will compare patients wearing conventional complete dentures, conventional removable partial dentures, mini-implant-retained overdentures, conventional implant-retained overdentures, and implant-assisted removable partial dentures. The longitudinal component will assess changes in masticatory performance, bite force, and patient-reported outcomes following prosthodontic rehabilitation and adaptation over time.

The study seeks to determine whether implant-assisted treatment options provide superior functional outcomes, oral health-related quality of life, and patient satisfaction compared with conventional removable prostheses.

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This study is active but is not currently recruiting participants.

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Key information

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

School of Dental Medicine, University of Zagreb, Zagreb, City of Zagreb, Croatia

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About this study

Tooth loss and edentulism are associated with impaired masticatory function, reduced bite force, compromised oral function, and decreased oral health-related quality of life. Conventional complete dentures and removable partial dentures remain widely used treatment modalities; however, limitations in retention, stability, and chewing efficiency may negatively affect patient satisfaction and functional outcomes. Implant-assisted treatment concepts, including mini-implant-retained overdentures, conventional implant-retained overdentures, and implant-assisted removable partial dentures, have been introduced to improve prosthesis retention, stability, comfort, and oral function.

The IMPROSTREHAB study (Implant and Prosthodontic Rehabilitation Outcomes Study) is an observational clinical study designed to evaluate functional and patient-reported outcomes associated with different removable prosthodontic treatment modalities in edentulous and partially edentulous patients.

The study comprises both cross-sectional and longitudinal components. In the cross-sectional component, masticatory efficiency, bite force, oral health-related quality of life, and patient-reported outcomes will be compared among individuals rehabilitated with conventional complete dentures (CDs), conventional removable partial dentures (RPDs), mini-implant-retained overdentures (MDI-ODs), conventional implant-retained overdentures (CI-ODs), and implant-assisted removable partial dentures (IARPDs). Additional analyses will evaluate the influence of demographic, clinical, anatomical, and prosthodontic factors, including age, sex, duration of prosthesis use, residual ridge resorption, number and distribution of remaining teeth, implant-related variables, and other factors that may influence treatment outcomes.

In the longitudinal component, participants receiving new prosthodontic treatment will be followed prospectively to assess changes in masticatory function, bite force, oral health-related quality of life, and patient-reported outcomes following treatment and adaptation to the prosthesis. Repeated assessments will be performed at predefined follow-up intervals according to the specific objectives of individual study subprojects.

Masticatory performance and masticatory efficiency will be evaluated using validated and standardized assessment methods, including chewing-gum mixing ability tests and other objective functional measures where appropriate. Maximum bite force will be assessed using calibrated bite-force measurement devices. Patient-reported outcomes will be evaluated using validated questionnaires and instruments, including measures of oral health-related quality of life, self-perceived chewing ability, denture satisfaction, treatment satisfaction, esthetic outcomes, and other patient-centered outcomes.

The primary objective of the study is to evaluate and compare masticatory efficiency and functional performance among different conventional and implant-assisted removable prosthodontic treatment modalities. Secondary objectives include the assessment of maximum bite force, oral health-related quality of life, chewing ability, patient satisfaction, esthetic outcomes, and other patient-reported outcomes, as well as the identification of factors associated with favorable functional and patient-centered treatment outcomes.

Participants will be recruited from the University of Zagreb School of Dental Medicine and affiliated clinical settings. Treatment allocation is not determined by the investigators but reflects routine clinical care and previously completed prosthodontic rehabilitation. The results of this study are expected to improve understanding of the functional and patient-centered benefits of contemporary removable prosthodontic treatment options and to support evidence-based clinical decision-making for edentulous and partially edentulous patients.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Inclusion Criteria:
  • Age 18 years or older.
  • Ability to understand the study procedures and provide written informed consent.
  • Wearing the respective prosthodontic restoration for at least 6 months (cross-sectional component).
  • Planned rehabilitation with one of the investigated prosthodontic treatment modalities (longitudinal component).
  • Ability to perform masticatory tests and complete questionnaires.

Exclusion criteria

  • Severe cognitive impairment or inability to complete questionnaires.
  • Neurological or muscular disorders affecting mastication.
  • Acute oral infections or untreated oral pathology.
  • Severe temporomandibular disorders causing pain or functional limitation.
  • Implant or prosthesis failure requiring immediate treatment.
  • Any medical condition that, in the opinion of the investigators, could affect study participation or outcome assessment.

Exclusion criteria

-

Treatment and study plan

Primary outcomes

  1. Masticatory Efficiency

    Time frame: Cross-sectional component: at study enrollment. Longitudinal component: baseline (before treatment), prosthesis delivery, 3 months, and 12 months after treatment.

    Assessment of masticatory efficiency using a standardized two-color chewing-gum mixing ability test. The degree of color mixing will be quantified using digital image analysis.

Secondary outcomes

  1. Maximum Bite Force

    Time frame: At study enrollment; baseline, prosthesis delivery, 3 months, and 12 months after treatment.

    Maximum voluntary bite force measured in Newtons (N) using a calibrated bite-force measurement device.

  2. Oral Health-Related Quality of Life (OHIP)

    Time frame: At study enrollment; baseline, 3 months, and 12 months after treatment.

    Oral Health Impact Profile questionnaire score.

  3. Self-Perceived Chewing Function (CFQ)

    Time frame: At study enrollment; baseline, 3 months, and 12 months after treatment.

    Chewing Function Questionnaire score.

  4. Orofacial Esthetics (OES)

    Time frame: At study enrollment; baseline, 3 months, and 12 months after treatment.

    Orofacial Esthetic Scale score.

  5. Residual Ridge Morphology

    Time frame: At study enrollment and baseline before treatment.

    Assessment of residual alveolar ridge morphology using the Cawood and Howell classification.

  6. Assessment of denture retention using the Modified Kapur Index.

    Time frame: Cross-sectional component: at study enrollment. Longitudinal component: prosthesis delivery, 3 months, and 12 months after treatment.

    Clinical assessment of denture retention and stability using the Modified Kapur Index. Retention and stability scores will be recorded according to standardized clinical criteria, with higher scores indicating improved prosthesis retention and stability.

Sponsors and collaborators

Lead sponsor

University of Zagreb

Other

Registry information

Official study title

Masticatory Efficiency, Bite Force, and Patient-Reported Outcomes in Patients Rehabilitated With Conventional Complete Dentures, Conventional Removable Partial Dentures, Mini-Implant-Retained Overdentures, Conventional Implant-Retained Overdentures, and Implant-Assisted Removable Partial Dentures: A Cross-Sectional and Longitudinal Clinical Study

Acronym: IMPROSTREHAB

Important dates

Study start
2025
Primary completion
2027
Study completion
2027
First posted
Jun 10, 2026
Registry last updated
Jun 10, 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.

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