Crown Removal in Non-Surgical Peri-Implantitis Therapy: A Randomized Trial

May 2, 2026 updated by: Michele Paolantonio, G. d'Annunzio University

Effectiveness of Non-Surgical Mechanical Therapy of Peri-Implantitis With or Without Prosthetic Crown Removal: A Randomized Controlled Trial

The aim of this single-blind, randomized controlled clinical trial is to evaluate whether removal of the prosthetic crown influences the clinical effectiveness of non-surgical mechanical therapy in implants affected by peri-implantitis.

The study is designed to compare changes in several clinical and radiographic parameters between baseline and follow-up examinations at 3, 6, and 12 months. The primary outcome measure will be the mean peri-implant probing depth (PIPD). Secondary outcomes will include changes in gingival recession (REC), radiographic marginal bone level (MBL), modified bleeding index (mBI), and additional patient-related variables.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

36

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • Italy
    • Chieti
      • Chieti, Chieti, Italy, 66100
        • Recruiting
        • Dental Clinic, Department of Innovative Technologies in Medicine and Dentistry, 'G. D'Annunzio' University of Chieti-Pescara
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Patients with at least one implant diagnosed with peri-implantitis (Berglundh et al., 2018);
  • Patients with a crown on the implant affected by peri-implantitis that is removable;
  • Patients who have not received non-surgical peri-implant therapy in the previous 6 months;
  • Patients who have not taken systemic antibiotic therapy in the previous 3 months.

Exclusion Criteria:

  • Full-Mouth Plaque Score (FMPS) > 30% at the time of non-surgical therapy;
  • Pregnant or breastfeeding women;
  • Relevant medical history, in the opinion of the examining clinician, that could affect the outcome of non-surgical peri-implant therapy;
  • Smoking patients consuming > 10 cigarettes/day.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Non-surgical therapy with prosthetic crown removal
Implants allocated to this group will receive non-surgical peri-implant therapy after temporary removal of the prosthetic crown. The crown will be unscrewed before treatment to allow direct access and full visibility of the implant surface and peri-implant tissues. Mechanical debridement will then be performed under local anesthesia using sonic and ultrasonic devices with dedicated thin tips and Gracey curettes, according to the EFP S3-level clinical practice guidelines. After completion of debridement and biofilm removal, the prosthetic crown will be reinstalled. Patients will receive oral hygiene instructions and reinforcement.
Procedure: Non-Surgical Peri-Implant Therapy without Crown
In this group, the prosthetic crown will be temporarily removed before treatment to allow direct and complete access to the peri-implant tissues and implant surface. After local anesthesia, a thorough mechanical debridement will be performed up to the bottom of the peri-implant pocket using sonic scalers, piezoelectric/ultrasonic devices with dedicated thin tips, and Gracey curettes. The absence of the crown enables improved visualization, more effective instrumentation, and more accurate disruption of the submucosal biofilm. At the end of the procedure, the prosthetic crown will be repositioned. Standardized oral hygiene instructions and motivation will be provided. This intervention aims to maximize cleaning efficacy by eliminating prosthetic-related access limitations.
Active Comparator: Non-surgical therapy without prosthetic crown removal
Implants allocated to this group will receive non-surgical peri-implant therapy with the prosthetic crown left in place. Mechanical debridement will be performed under local anesthesia using the same instruments and protocol as in the test group (sonic scaler, ultrasonic devices, and Gracey curettes), but with access limited by the presence of the restoration. Professional oral hygiene instructions and reinforcement will also be provided.
Procedure: Non-Surgical Peri-Implant Therapy with Crown
In this group, non-surgical mechanical therapy will be carried out with the prosthetic crown left in place. After local anesthesia, debridement of the peri-implant pocket will be performed using the same instruments and protocol as in the test group, including sonic scalers, ultrasonic devices with thin tips, and Gracey curettes. The presence of the crown limits access to some peri-implant areas and reflects routine clinical practice. Patients will receive standardized oral hygiene instructions and reinforcement. This intervention represents the conventional non-surgical management of peri-implantitis without removal of the restoration

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Peri-implant probing depth (PIPD)
Time Frame: From enrollment to the end of treatment at 1 year
Change in mean peri-implant probing depth (PIPD) at the implant level (measured at 6 sites per implant) from baseline to 3, 6, and 12 months after crown removal.
From enrollment to the end of treatment at 1 year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

G. d'Annunzio University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 20, 2026

Primary Completion (Estimated)

July 31, 2027

Study Completion (Estimated)

July 31, 2027

Study Registration Dates

First Submitted

January 29, 2026

First Submitted That Met QC Criteria

January 29, 2026

First Posted (Actual)

February 5, 2026

Study Record Updates

Last Update Posted (Actual)

May 7, 2026

Last Update Submitted That Met QC Criteria

May 2, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 29012026

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Peri-implantitis

Clinical Trials on Non-Surgical Peri-Implant Therapy without Crown

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Germany

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe