Antimicrobial Photodynamic Therapy in the Endodontic Treatment of Anterior Primary Teeth With Pulp Necrosis

September 13, 2026 updated by: Sandra Kalil Bussadori, University of Nove de Julho

Antimicrobial Photodynamic Therapy in the Endodontic Treatment of Anterior Primary Teeth With Pulp Necrosis: A Randomized Controlled Clinical Trial With Microbiological Analysis and Blinded Assessment of Clinical and Radiographic Outcomes

This randomized controlled clinical trial evaluated the immediate reduction in intracanal microbial load and the short-term clinical and radiographic progression of anterior primary teeth with pulp necrosis after conventional endodontic treatment or antimicrobial photodynamic therapy (aPDT). Seven children aged 2 to 5 years contributed 20 eligible single-rooted anterior primary teeth. Teeth were randomized to conventional endodontic treatment (10 teeth) or aPDT (10 teeth). The primary outcome was intracanal microbial load before and immediately after the assigned first-session intervention. Clinical outcomes were assessed at 7 days, 1 month, and 3 months, and radiographic outcomes were assessed at 1 and 3 months.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The tooth was the unit of randomization and analysis. Some participants contributed more than one eligible tooth and could have teeth allocated to both study arms. Each eligible tooth was independently randomized using opaque, sealed, sequentially numbered envelopes.

After coronal access and working-length determination, three sterile paper points were maintained in the root canal for 30 seconds to obtain the baseline microbiological sample (S1).

In the conventional-treatment arm, S1 collection was followed by chemomechanical preparation using K-files, 1% sodium hypochlorite, and Endo PTC. A second microbiological sample (S2) was then collected.

In the aPDT arm, S1 collection was followed by intracanal application of 0.005% methylene blue for 3 minutes. Irradiation was performed with a Therapy XT red laser in continuous-wave mode at 660 nm, with a mean radiant power of 100 mW, for 90 seconds, delivering a radiant energy of 9 J through an intracanal optical fiber. The canal was then irrigated with sterile saline, and S2 was collected. No chemomechanical preparation, instrumentation, or sodium hypochlorite irrigation was performed in the aPDT arm before S2 collection.

After S2 collection, teeth in both arms received UltraCal XS calcium hydroxide intracanal medication, a thin gutta-percha base, and provisional sealing with glass ionomer cement. After 7 days, the teeth were reopened, the intracanal medication was removed, the canals were irrigated with 1% sodium hypochlorite, and definitive root canal filling was performed using Guedes-Pinto iodoform paste. Restorative treatment was performed in a subsequent session.

Clinical assessments were performed at 7 days, 1 month, and 3 months. Radiographic assessments were performed at 1 and 3 months. Conventional rescue treatment was planned for teeth in the aPDT arm if pain, fistula, swelling, or other signs and symptoms persisted or worsened.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
7

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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 Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Brazil
      • São Paulo, Brazil, 04106001
        • University of Nove de Julho

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

9 months to 2 years (Child)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Children of either sex, aged 2 to 5 years, in the primary dentition stage.
  • At least one restorable single-rooted anterior primary tooth with pulp necrosis caused by deep caries or dental trauma.
  • At least two-thirds of the root remaining.
  • Sufficient cooperation to allow safe clinical treatment.
  • No systemic antibiotic therapy during the previous 3 months.
  • Written informed consent provided by a parent or legal guardian.

Exclusion Criteria:

  • Root resorption involving two-thirds or more of the root.
  • Involvement of the permanent successor tooth crypt.
  • Tooth requiring immediate extraction or not amenable to endodontic treatment.
  • Compromised systemic health or uncontrolled chronic disease.
  • Recent antibiotic use capable of affecting microbiological results.
  • Noncooperative behavior that precluded safe clinical treatment.

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

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Conventional Endodontic Treatment
After baseline microbiological sampling, teeth underwent chemomechanical root canal preparation using K-files, 1% sodium hypochlorite, and Endo PTC. The immediate post-intervention microbiological sample was then collected. Calcium hydroxide medication and provisional sealing were placed, followed by definitive root canal filling after 7 days.
Procedure: Conventional Endodontic Treatment
Following coronal access, an initial microbiological sample (S1) was collected. Chemomechanical preparation was performed using K-files, Endo PTC, and irrigation and aspiration with 1% sodium hypochlorite. A second microbiological sample (S2) was then collected. Calcium hydroxide intracanal medication was placed, and the tooth was temporarily sealed. After 7 days, the medication was removed, the canal was irrigated with 1% sodium hypochlorite, and definitive root canal filling was performed using Guedes-Pinto iodoform paste.
Experimental: Antimicrobial Photodynamic Therapy
After baseline microbiological sampling, teeth received intracanal 0.005% methylene blue for 3 minutes, followed by red-laser irradiation at 660 nm, 100 mW, for 90 seconds, delivering 9 J through an intracanal optical fiber. No chemomechanical preparation, instrumentation, or sodium hypochlorite irrigation was performed before the immediate post-intervention sample. Calcium hydroxide medication and provisional sealing were placed, followed by definitive root canal filling after 7 days. Conventional rescue treatment was planned if symptoms persisted or worsened.
Procedure: Antimicrobial Photodynamic Therapy
Following coronal access, an initial microbiological sample (S1) was collected. Methylene blue at 0.005% was placed inside the root canal for a 3-minute pre-irradiation period. Irradiation was performed using a Therapy XT red laser at 660 nm, 100 mW, for 90 seconds, delivering 9 J through an intracanal optical fiber. No chemomechanical preparation, instrumentation, or sodium hypochlorite irrigation was performed before S2. After irrigation with sterile saline, the second microbiological sample (S2) was collected. Calcium hydroxide intracanal medication was placed, and the tooth was temporarily sealed. After 7 days, the medication was removed, the canal was irrigated with 1% sodium hypochlorite, and definitive root canal filling was performed using Guedes-Pinto iodoform paste.
Other Names:
  • aPDT

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in Intracanal Microbial Load From Baseline to Immediately Post-intervention
Time Frame: Baseline and immediately post-intervention on Day 0
Viable intracanal microorganisms were quantified as colony-forming units per milliliter and transformed to log10 CFU/mL. Samples were collected using three sterile paper points maintained in the root canal for 30 seconds. S1 was collected before the assigned intervention. S2 was collected after chemomechanical preparation in the conventional-treatment arm and immediately after aPDT in the experimental arm. Change was calculated as S2 minus S1; more negative values indicate a greater reduction in viable microbial load.
Baseline and immediately post-intervention on Day 0

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Number of Treated Teeth With Clinical Signs or Symptoms
Time Frame: 7 days, 1 month, and 3 months
The presence or absence of pain, fistula, swelling, abscess, pathological mobility, need for systemic antibiotics, emergency dental care, or an additional intervention related to the treated tooth was recorded at each follow-up. The outcome was reported as the number of teeth with at least one clinical sign or symptom.
7 days, 1 month, and 3 months
Number of Treated Teeth With a Periapical or Periradicular Lesion
Time Frame: 1 month and 3 months.
The presence or absence of a periapical or periradicular lesion was assessed on standardized radiographs by two blinded examiners. The outcome was reported as the number of teeth with a lesion at each follow-up.
1 month and 3 months.
Number of Treated Teeth Without Radiographic Worsening
Time Frame: 1 month and 3 months
Standardized radiographs were assessed by two blinded examiners. Absence of radiographic worsening was defined as no progression or development of adverse periapical or periradicular findings, with maintenance or improvement of the radiographic condition.
1 month and 3 months
Number of Treated Teeth With Pathological Root Resorption
Time Frame: 1 month and 3 months
The presence or absence of pathological root resorption was assessed on standardized radiographs by two blinded examiners. The outcome was reported as the number of teeth with pathological root resorption at each follow-up.
1 month and 3 months

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Nove de Julho

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Sandra Bussadori, PhD, University of Nove de Julho

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 1, 2025

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
February 1, 2026

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
May 1, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 9, 2015

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 25, 2015

First Posted (Estimated)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 30, 2015

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 16, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 13, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • aPDTEndo
  • 19373019.1.0000.5511 (Other Identifier: Plataforma Brasil)

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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