Antibacterial Activity of Calcium Hydroxide and Betamethasone in Apical Periodontitis

January 10, 2026 updated by: Duygu Degirmencioglu

Antibacterial Efficacy of Calcium Hydroxide Used Alone or in Combination With Iodoform (Metapex) and Steroid (Betamethasone) in Patients With Apical Periodontitis

Apical periodontitis is a chronic inflammatory disease caused by bacterial infection of the root canal system. Although mechanical cleaning and shaping reduce most microorganisms, bacteria may persist in areas that are difficult to reach, making the use of intracanal medicaments between treatment sessions clinically important.

Calcium hydroxide is one of the most commonly used intracanal medicaments because of its antibacterial properties. However, some resistant microorganisms, such as Enterococcus faecalis, may survive when calcium hydroxide is used alone. Therefore, combining calcium hydroxide with other agents, such as iodoform or corticosteroids, may improve its antibacterial effectiveness.

The purpose of this study is to compare the antibacterial activity of calcium hydroxide used alone or in combination with iodoform (Metapex) or betamethasone in patients with apical periodontitis. Bacterial load in root canals will be evaluated using droplet digital PCR (ddPCR), a highly sensitive molecular method that allows absolute quantification of bacteria. The results of this study are expected to provide evidence to support optimal intracanal medicament selection in endodontic retreatment cases.

Study Overview

Status

Not yet recruiting

Conditions

Detailed Description

Apical periodontitis is a chronic inflammatory condition of periapical tissues that develops as a result of persistent bacterial infection within the root canal system. While chemomechanical preparation significantly reduces the microbial load, bacteria may remain in anatomical complexities such as dentinal tubules, isthmuses, and apical ramifications. For this reason, intracanal medicaments are widely used between treatment sessions to enhance disinfection and improve treatment outcomes.

Calcium hydroxide is the most frequently used intracanal medicament due to its high pH and antibacterial properties. Nevertheless, certain microorganisms, particularly Enterococcus faecalis, have been shown to survive in alkaline environments, limiting the effectiveness of calcium hydroxide when used alone. To overcome this limitation, calcium hydroxide has been combined with various agents, including iodoform and corticosteroids, with the aim of enhancing antibacterial activity and reducing periapical inflammation.

Droplet digital PCR (ddPCR) is a novel molecular technique that enables absolute quantification of bacterial DNA without the need for standard curves and is less affected by PCR inhibitors compared to conventional quantitative PCR methods. Despite its advantages, the use of ddPCR in clinical endodontic research remains limited, particularly in in vivo studies evaluating intracanal medicaments.

This prospective, single-center clinical study aims to compare the antibacterial efficacy of three intracanal medicament protocols in patients with apical periodontitis undergoing endodontic retreatment: (1) calcium hydroxide alone, (2) calcium hydroxide combined with iodoform (Metapex), and (3) calcium hydroxide combined with betamethasone. Root canal samples will be collected at different treatment stages, and total bacterial load as well as Enterococcus faecalis levels will be quantified using ddPCR.

The findings of this study are expected to provide high-quality clinical evidence regarding the antibacterial effectiveness of commonly used intracanal medicaments and their combinations. The results may contribute to evidence-based decision-making in the selection of intracanal medicaments for the management of apical periodontitis, particularly in retreatment cases.

Study Type

Observational

Enrollment (Estimated)

45

Contacts and Locations

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

Study Locations

  • Turkey (Türkiye)
    • Istanbul
      • Istanbul, Istanbul, Turkey (Türkiye), 34810
        • Istanbul Medipol University Faculty of Dentistry
        • Contact:
        • Principal Investigator:
          • Duygu Degirmencioglu

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

No

Sampling Method

Non-Probability Sample

Study Population

The study population consists of adult patients diagnosed with apical periodontitis who require endodontic retreatment and are treated at a single academic dental center.

Description

Inclusion Criteria:

  • - Adults aged 18 to 65 years.
  • Patients diagnosed with apical periodontitis requiring endodontic retreatment.
  • Presence of a single tooth with radiographic evidence of apical periodontitis.
  • Ability to provide written informed consent.

Exclusion Criteria:

  • Use of systemic antibiotics within the previous 3 months.
  • Presence of systemic diseases that may affect healing or immune response.
  • Pregnancy or lactation.
  • Known allergy or hypersensitivity to any of the intracanal medicaments used.
  • Teeth with acute abscess, severe periodontal disease, or root fractures.

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

Cohorts and Interventions

Group / Cohort
Calcium Hydroxide
This cohort includes patients with apical periodontitis undergoing endodontic retreatment who receive calcium hydroxide as an intracanal medicament as part of routine clinical care. The selection of the intracanal medicament is based on standard clinical decision-making and is not assigned by the study protocol.
Calcium Hydroxide + Iodoform (Metapex)
This cohort includes patients with apical periodontitis undergoing endodontic retreatment who receive a combination of calcium hydroxide and iodoform (Metapex) as an intracanal medicament as part of routine clinical care. The intracanal medicament is selected according to standard clinical practice and is not assigned by the study protocol.
Calcium Hydroxide + Betamethasone
This cohort includes patients with apical periodontitis undergoing endodontic retreatment who receive a combination of calcium hydroxide and betamethasone as an intracanal medicament as part of routine clinical care. The choice of intracanal medicament is determined by routine clinical decision-making and is not assigned by the study protocol.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Total Bacterial Load in Root Canal Samples
Time Frame: From baseline to 7 days after intracanal medicament application
The primary outcome is the change in total bacterial load in root canal samples collected during endodontic retreatment. Bacterial load will be quantified using droplet digital PCR (ddPCR) by measuring absolute bacterial DNA copy numbers at different treatment stages.
From baseline to 7 days after intracanal medicament application

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Enterococcus faecalis Levels
Time Frame: From baseline to 7 days after intracanal medicament application
This secondary outcome assesses the change in Enterococcus faecalis levels in root canal samples collected during endodontic retreatment. Enterococcus faecalis DNA will be quantified using droplet digital PCR (ddPCR) by measuring absolute DNA copy numbers before and after intracanal medicament application.
From baseline to 7 days after intracanal medicament application

Collaborators and Investigators

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

Sponsor

Duygu Degirmencioglu

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 (Estimated)

March 1, 2026

Primary Completion (Estimated)

November 1, 2026

Study Completion (Estimated)

March 1, 2027

Study Registration Dates

First Submitted

January 10, 2026

First Submitted That Met QC Criteria

January 10, 2026

First Posted (Actual)

January 20, 2026

Study Record Updates

Last Update Posted (Actual)

January 20, 2026

Last Update Submitted That Met QC Criteria

January 10, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • MedipolU-629

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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