Microbiological Evaluation of the Effectiveness of Different Surface Decontamination Protocols for Dental Implants

April 7, 2026 updated by: Igor Smojver, University of Zagreb

Microbiological Evaluation of the Effectiveness of Different Surface Decontamination Protocols for Dental Implants Using the Polymerase Chain Reaction Method

The purpose of this prospective clinical study is to evaluate and compare the effectiveness of different cleaning (decontamination) methods for dental implants affected by peri-implantitis. Peri-implantitis is an inflammatory condition caused by a bacterial biofilm on the implant surface, which can lead to bone loss and implant failure if left untreated. Because the rough surface and threads of implants make them difficult to clean, finding the most effective decontamination method is critical for saving the implant.

This study will include 90 healthy, non-smoking participants who have a bone-level dental implant affected by peri-implantitis without vertical bone loss. Participants will be randomly assigned to one of three treatment groups (30 implants per group) to undergo a specific decontamination procedure during their surgical treatment:

Group 1 (Laser PDT): Decontamination using photodynamic therapy with a blue laser and riboflavin, followed by a sterile saline rinse.

Group 2 (GalvoSurge): Decontamination using an electrolytic cleaning device, followed by a sterile saline rinse.

Group 3 (Active Control): Decontamination using a 0.2% chlorhexidine gluconate rinse, which is the current standard of care.

To measure the effectiveness of these treatments, researchers will take sterile swabs from the implant surface immediately before and after the decontamination process. These swabs will be analyzed using PCR to detect changes in the microbiological load of five specific bacteria known to cause gum and implant disease (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola, and Tannerella forsythia).

Following the decontamination and swabbing, all participants will receive a standard Guided Bone Regeneration (GBR) procedure using autogenous bone, a xenograft, and a collagen membrane to help rebuild the bone around the implant.

By comparing the microbiological results before and after treatment, the study aims to determine whether the newer methods (Laser PDT or electrolytic cleaning) are more effective at removing harmful bacteria than the traditional chlorhexidine rinse prior to bone regeneration.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Background and Rationale Contemporary dental implantology represents a reliable and predictable treatment method for partial or complete tooth loss. However, despite high success rates, complications such as peri-implantitis can lead to implant loss, significantly impacting patients functionally, emotionally, and financially. Peri-implantitis is an inflammatory condition affecting the soft and hard tissues surrounding an osseointegrated dental implant, with a prevalence of approximately 20% among patients undergoing implant therapy.

The primary etiological factor for peri-implantitis is the formation of a bacterial biofilm on the exposed surface of the implant. Biofilm formation is a complex, multi-step process involving the colonization of bacteria from around the implants, natural teeth, and other areas of the oral cavity. The oral biofilm associated with peri-implantitis is characterized by high microbial diversity. While no single specific bacterium has been identified as exclusively present in peri-implantitis biofilms, the long-term presence of this biofilm stimulates a host immune response, leading to chronic inflammation and subsequent tissue destruction.

The Clinical Challenge One of the most demanding and critical tasks in the treatment of peri-implantitis is the complete removal of the biofilm and the prevention of its recurrence. The presence of deep peri-implant pockets, restricted access to all implant surfaces, and the inherently rough, threaded topography of dental implants make mechanical and chemical decontamination exceptionally challenging.

Traditionally, mechanical tools such as curettes, sonic and ultrasonic instruments, air-polishing devices, and rotating titanium or chitosan brushes have been utilized to remove hard and soft deposits. A key clinical requirement is to achieve this with minimal damage or alteration to the implant surface. To address this, chemical agents (e.g., sterile saline, hydrogen peroxide, citric acid, EDTA, phosphoric acid, and chlorhexidine gluconate) are often employed alongside mechanical methods.

Recently, novel modalities have emerged to minimize surface damage while maximizing antimicrobial efficacy:

Antimicrobial Photodynamic Therapy (aPDT): Based on a photochemical reaction between a photosensitizer, oxygen, and a specific light wavelength, this therapy generates reactive oxygen species that induce bacterial cell death.

Electrolytic Cleaning (GalvoSurge): This method utilizes an electrolytic process to actively lift and eliminate bacterial biofilms from rough titanium surfaces, demonstrating promising in vitro results.

Study Objectives This prospective clinical trial is designed to evaluate and compare the antimicrobial efficacy of two novel implant decontamination protocols-Laser PDT and Electrolytic Cleaning (GalvoSurge)-against the widely accepted gold standard of 0.2% chlorhexidine gluconate rinsing. The primary focus is assessing the reduction of the microbiological load on the implant surface immediately following decontamination and prior to regenerative bone surgery.

Methodology and Clinical Protocol The study will be conducted at the School of Dental Medicine, University of Zagreb, within the Department of Oral Surgery. All surgical procedures will be performed by the same specialist in oral surgery to ensure procedural consistency.

The trial will enroll 90 bone-level dental implants affected by peri-implantitis but deemed viable for retention in the dental arch. Implants with vertical bone loss are excluded from this study. Eligible participants are restricted to healthy, non-smoking individuals classified as ASA I or II, with no systemic comorbidities. Pre-operative assessment will include Cone Beam Computed Tomography (CBCT) imaging.

The clinical workflow for each implant is as follows:

Flap Elevation: A mucoperiosteal flap is raised to expose the contaminated implant surface.

Baseline Sampling (Sample 1): A sterile swab is taken directly from the implant surface for initial PCR analysis to establish the baseline microbiological load.

Randomization and Intervention: Implants are randomly assigned to one of three treatment arms (n=30 per arm):

Group 1: Decontamination using Laser PDT (riboflavin photosensitizer + blue laser) followed by a sterile saline rinse.

Group 2: Decontamination using the GalvoSurge electrolytic system followed by a sterile saline rinse.

Group 3 (Active Control): Decontamination using a 0.2% chlorhexidine gluconate rinse.

Post-Treatment Sampling (Sample 2): Immediately following the decontamination protocol, a second sterile swab is taken for PCR analysis.

Regenerative Procedure: The surgery concludes with a classic Guided Bone Regeneration (GBR) procedure, utilizing autologous bone particles, a xenograft, and a collagen membrane fixed in place with titanium pins.

Microbiological Analysis

Samples will be analyzed using a validated real-time Polymerase Chain Reaction (RT-PCR) method targeting five specific periodontopathogenic bacteria:

Aggregatibacter actinomycetemcomitans

Porphyromonas gingivalis

Prevotella intermedia

Treponema denticola

Tannerella forsythia

The primary outcome is the change in the microbiological load. Results will be expressed as a semi-quantitative score (-, +, ++, +++), which will be numerically coded for statistical evaluation. The change is calculated as the difference between the post-treatment and pre-treatment values for each specific implant.

Sample Size and Statistical Analysis Plan The study is designed as a prospective comparative trial with repeated measures. Sample size estimations were based on available in vitro studies demonstrating a large effect size for electrolytic decontamination compared to standard methods.

Power Calculation: Assuming a conservative large standardized effect size (Cohen's d ≈ 0.9), a two-sided significance level of α = 0.05, and a test power of 80%, a minimum of 25 implants per group is required to detect statistically significant differences between the test groups and the control group. To account for potential sample loss or unusable swabs, the enrollment target was increased to 30 implants per group (90 implants total).

Data Analysis: Statistical significance is set at 95% (p < 0.05). Normal distribution of the data will be assessed descriptively and via formal tests.

For normally distributed data, a one-way Analysis of Variance (ANOVA) will be utilized, followed by post-hoc comparisons of each test group against the control group.

If assumptions for parametric testing are not met, appropriate non-parametric alternatives will be applied.

Differences between baseline and post-treatment values within individual groups will be analyzed using tests for dependent samples.

Qualitative outcomes (e.g., the positive or negative presence of the target pathogens) will be evaluated using categorical data methodologies.

Hypothesis: Based on preliminary in vitro findings, the investigators anticipate a more pronounced therapeutic and antimicrobial effect in the GalvoSurge electrolytic cleaning group compared to the control.

Study Type

Interventional

Enrollment (Estimated)

90

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

  • Name: Igor Smojver, DMD;PhD
  • Phone Number: 385981651932
  • Email: ismojver@sfzg.hr

Study Locations

  • Croatia
      • Zagreb, Croatia, 10000
        • Recruiting
        • School of Dental Medicine
        • 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

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

Patients presenting with at least one bone-level dental implant affected by peri-implantitis.

The affected implant must be deemed viable with a perspective for preservation/retention in the dental arch.

Patients must be non-smokers.

Patients in good general health, classified as ASA I (a normal healthy patient) or ASA II (a patient with mild systemic disease) according to the American Society of Anesthesiologists physical status classification system.

Exclusion Criteria:

Presence of vertical bone loss around the affected implant.

Implants that are not bone-level (e.g., tissue-level implants).

Patients with any systemic comorbidities.

Patients who are currently smokers.

Implants with a poor prognosis that cannot be preserved in the dental arch.

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: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Laser PDT + Saline Rinse

Implants in this group will undergo surface decontamination using Photodynamic Therapy (PDT). This involves the application of a riboflavin photosensitizer activated by a blue laser, followed by a rinse with sterile normal saline solution. The decontamination is performed immediately after the baseline microbiological swab (Sample 1) and before the post-treatment swab (Sample 2). All implants will subsequently receive a standard Guided Bone Regeneration (GBR) procedure.

Interventions:

Device / Procedure: Laser Photodynamic Therapy (PDT)

Procedure: Guided Bone Regeneration (GBR)
Device: Laser Photodynamic Therapy (PDT)

Antimicrobial photodynamic therapy applied to the contaminated implant surface. This involves the application of a riboflavin photosensitizer which is then activated by a blue laser to generate reactive oxygen species and eliminate bacterial biofilm. The procedure is concluded with a sterile normal saline rinse.

Arm Group(s): Laser PDT + Saline Rinse

Procedure: Guided Bone Regeneration (GBR)

A classic surgical bone grafting procedure performed on all implants immediately following their assigned decontamination protocol. The procedure involves placing a mixture of autologous bone particles and a xenograft around the implant, which is then covered by a collagen membrane fixed in place using titanium pins.

Arm Group(s): Laser PDT + Saline Rinse; GalvoSurge + Saline Rinse; Chlorhexidine Rinse (Control)
Experimental: GalvoSurge + Saline Rinse

Implants in this group will undergo surface decontamination using the GalvoSurge electrolytic cleaning system, followed by a rinse with sterile normal saline solution. The decontamination is performed immediately after the baseline microbiological swab (Sample 1) and before the post-treatment swab (Sample 2). All implants will subsequently receive a standard Guided Bone Regeneration (GBR) procedure.

Interventions:

Device / Procedure: GalvoSurge Electrolytic Cleaning

Procedure: Guided Bone Regeneration (GBR)
Procedure: Guided Bone Regeneration (GBR)

A classic surgical bone grafting procedure performed on all implants immediately following their assigned decontamination protocol. The procedure involves placing a mixture of autologous bone particles and a xenograft around the implant, which is then covered by a collagen membrane fixed in place using titanium pins.

Arm Group(s): Laser PDT + Saline Rinse; GalvoSurge + Saline Rinse; Chlorhexidine Rinse (Control)

Device: GalvoSurge Electrolytic Cleaning

Decontamination of the implant surface using the GalvoSurge dental device. This system utilizes an electrolytic process with a specific cleaning solution to actively lift and detach the bacterial biofilm from the rough titanium surface. The procedure is concluded with a sterile normal saline rinse.

Arm Group(s): GalvoSurge + Saline Rinse
Active Comparator: Chlorhexidine Rinse (Control)

Implants in this control group will undergo surface decontamination using the current clinical gold standard, which is a 0.2% chlorhexidine gluconate rinse. The decontamination is performed immediately after the baseline microbiological swab (Sample 1) and before the post-treatment swab (Sample 2). All implants will subsequently receive a standard Guided Bone Regeneration (GBR) procedure.

Interventions:

Drug / Procedure: 0.2% Chlorhexidine Gluconate Rinse

Procedure: Guided Bone Regeneration (GBR)
Procedure: Guided Bone Regeneration (GBR)

A classic surgical bone grafting procedure performed on all implants immediately following their assigned decontamination protocol. The procedure involves placing a mixture of autologous bone particles and a xenograft around the implant, which is then covered by a collagen membrane fixed in place using titanium pins.

Arm Group(s): Laser PDT + Saline Rinse; GalvoSurge + Saline Rinse; Chlorhexidine Rinse (Control)

Drug: 0.2% Chlorhexidine Gluconate

Chemical decontamination of the implant surface by rinsing it thoroughly with a 0.2% chlorhexidine gluconate solution, which serves as the active control/gold standard for antimicrobial reduction.

Arm Group(s): Chlorhexidine Rinse (Control)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Microbiological Load of Periodontopathogenic Bacteria
Time Frame: Intraoperatively: Measured immediately before the decontamination procedure (baseline) and immediately after the completion of the decontamination procedure (prior to bone regeneration).
The primary outcome evaluates the effectiveness of the decontamination protocols by measuring the change in the bacterial load on the implant surface. Sterile swabs taken before and after the intervention are analyzed using a validated real-time Polymerase Chain Reaction (RT-PCR) method to detect five specific periodontopathogenic bacteria (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola, and Tannerella forsythia). The microbiological load is expressed as a semi-quantitative score (-, +, ++, +++), which is then numerically coded for statistical analysis. The primary measure is the calculated difference (change) between the post-treatment and baseline pre-treatment scores for each individual implant.
Intraoperatively: Measured immediately before the decontamination procedure (baseline) and immediately after the completion of the decontamination procedure (prior to bone regeneration).

Collaborators and Investigators

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

Sponsor

University of Zagreb

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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)

March 1, 2026

Primary Completion (Estimated)

March 1, 2027

Study Completion (Estimated)

June 1, 2027

Study Registration Dates

First Submitted

April 7, 2026

First Submitted That Met QC Criteria

April 7, 2026

First Posted (Actual)

April 14, 2026

Study Record Updates

Last Update Posted (Actual)

April 14, 2026

Last Update Submitted That Met QC Criteria

April 7, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 123456789 (Bandirma Onyedi Eylul University)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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.

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