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.

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.

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:

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The study population will comprise edentulous and partially edentulous adult patients treated at the Department of Prosthodontics, University of Zagreb School of Dental Medicine. Participants will include wearers of conventional complete dentures, conventional removable partial dentures, mini-implant-retained overdentures, conventional implant-retained overdentures, mini-implant-assisted removable partial dentures, and implant-assisted removable partial dentures. Additional participants undergoing prosthodontic rehabilitation will be prospectively recruited for the longitudinal component of the study.