Root Canal InfectionNCT07266233
Toluidine Blue-Based Photodynamic Therapy for Antibacterial Activity and Postoperative Pain
A study testing Toluidine Blue O (0.1 mg/mL), 630-nm LED Light Device and Photodynamic Therapy (PDT) in people with Root Canal Infection, run by Ataturk University at 1 site in Turkey (Türkiye).
Trial summary
This clinical study aims to evaluate the antimicrobial effectiveness and postoperative pain outcomes of photodynamic therapy using Toluidine Blue O as an adjunct to conventional root canal treatment in patients diagnosed with symptomatic irreversible pulpitis. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Root Canal Infection
- What is being tested?
- Toluidine Blue O (0.1 mg/mL), 630-nm LED Light Device and Photodynamic Therapy (PDT)
- Type of treatment
- Medical device, Surgery or procedure
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 50 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Jun 2025to Mar 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patients aged between 18 and 65 years
- Presence of asymptomatic apical periodontitis with necrotic pulp in single-rooted maxillary or mandibular incisors, canines, or premolars
- Periapical Index (PAI) score ≥ 2
- Patients classified as ASA I (American Society of Anesthesiologists Physical Status Classification)
- Preoperative pain score < 50 on the Visual Analog Scale (VAS)
Who cannot join
- Multi-rooted teeth
- Patients classified as ASA II or higher
- Pregnant women or those with suspected pregnancy
- Root canal curvature greater than 25° according to the Schilder method
- Patients diagnosed with generalized periodontitis
- Periodontal pocket depth > 3 mm in the related tooth
Show all 9Show fewer
- Use of analgesic medication within the past 72 hours
- Use of antibiotic therapy within the past month
- Presence of swelling and positive response to palpation/percussion tests
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Atatürk University, Faculty of Dentistry, Department of Endodontics
Erzurum
About this study
Official title: Evaluation of the Antibacterial Activity and Postoperative Pain Outcomes of Photodynamic Therapy Using Toluidine Blue
This clinical study aims to evaluate the antimicrobial effectiveness and postoperative pain outcomes of photodynamic therapy using Toluidine Blue O as an adjunct to conventional root canal treatment in patients diagnosed with symptomatic irreversible pulpitis. Photodynamic therapy is a non-invasive light-activated disinfection method, and this study will compare its performance with standard endodontic treatment protocols. The results are expected to provide clinical evidence regarding its potential benefits in reducing intracanal bacterial load and improving postoperative patient comfort.
Read the detailed description
This randomized clinical study is designed to investigate the antimicrobial effectiveness and postoperative pain outcomes of photodynamic therapy (PDT) using toluidine blue O (TBO) as an adjunct to conventional root canal treatment in single-rooted teeth with necrotic pulps. The rationale for this research is based on the persistent difficulty of achieving complete microbial elimination from the root canal system using standard chemomechanical preparation alone. Toluidine blue O-mediated PDT has been proposed as a minimally invasive disinfection method capable of producing reactive oxygen species after activation with visible light, thereby enhancing microbial reduction beyond that achieved by irrigation protocols.
The study employs a standardized protocol in which intracanal microbiological sampling is conducted at four predefined stages to monitor changes in microbial load throughout treatment. All samples are stored and analyzed using real-time quantitative polymerase chain reaction (qPCR), which allows sensitive detection and quantification of bacterial DNA. This molecular approach offers advantages over culture-based methods by identifying uncultivable or low-abundance bacterial species, providing a more comprehensive evaluation of the antimicrobial effect of PDT.
In the experimental group, photodynamic therapy is performed by introducing a 0.1 mg/mL toluidine blue O solution into the prepared root canal, followed by activation with a 630-nm LED light source. The choice of this wavelength corresponds to the absorption peak of TBO and optimizes energy transfer for singlet oxygen production. A sham procedure is used in the control group to maintain participant masking and ensure methodological consistency. Both groups receive identical chemomechanical preparation and irrigation procedures prior to the assigned intervention.
Pain assessment during the postoperative period is performed using a validated visual analog scale (VAS), providing continuous measurement of patient-reported discomfort during the first week after treatment. The integration of molecular microbiology with clinical pain evaluation allows a combined assessment of both biological and patient-centered outcomes. This study is expected to contribute new in-vivo evidence on the potential benefits of toluidine blue O-based PDT as an adjunctive disinfection method in endodontic therapy.
- Conditions
- Root Canal Infection
- Being tested
- Toluidine Blue O (0.1 mg/mL), 630-nm LED Light Device, Photodynamic Therapy (PDT), Sham Photodynamic Therapy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Toluidine Blue O (0.1 mg/mL)Drug
A 0.1 mg/mL toluidine blue O solution used as the photosensitizer for photodynamic therapy. The solution is placed into the root canal prior to 630-nm LED irradiation for activation.
630-nm LED Light DeviceDevice
A light-emitting diode device delivering 630-nm wavelength used to activate toluidine blue O during photodynamic therapy. The device is positioned near the tooth for 60 seconds.
Photodynamic Therapy (PDT)Procedure or surgery
Application of 0.1 mg/mL toluidine blue O into the root canal, followed by activation with a 630-nm LED light source for 60 seconds as part of the experimental disinfection protocol.
Sham Photodynamic TherapyProcedure or surgery
Placebo photodynamic procedure in which the LED device is positioned similarly but activated without delivering light energy; no toluidine blue O is applied.
| Study group | Role | What they receive |
|---|---|---|
| Control Group (Sham PDT) | Placebo comparator | Participants in this arm will receive the standard root canal irrigation protocol using 2.5% sodium hypochlorite and 17% EDTA. A sham photodynamic procedure will be performed by positioning the LED device near the tooth without light activation to simulate photodynamic therapy conditions. No Toluidine Blue O will be applied, and no active light irradiation will be performed Receives: Procedure: Sham Photodynamic Therapy |
| Experimental Group (PDT) | Experimental | Participants in this arm will receive the standard root canal irrigation protocol followed by adjunctive photodynamic therapy. A 0.1 mg/mL Toluidine Blue O solution will be delivered into the canal and activated with a 630-nm LED light using an optical fiber for 60 seconds. This procedure will be performed after instrumentation and prior to final assessment sampling. Receives: Drug: Toluidine Blue O (0.1 mg/mL); Device: 630-nm LED Light Device; Procedure: Photodynamic Therapy (PDT) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Reduction in intracanal bacterial load measured by quantitative PCR (qPCR)
Intracanal bacterial load will be quantified using real-time quantitative polymerase chain reaction (qPCR). Samples will be collected at four predefined sampling points (S0-S3) using sterile #30 paper points inserted into the canal for 30 seconds.
S0 (Baseline): After isolation and disinfection, before instrumentation
S1: After access cavity preparation and working length determination
S2: After root canal instrumentation
S3 (Post-Intervention): After final irrigation protocol and photodynamic therapy (or sham procedure)
Changes in bacterial DNA concentration (copy number/µL) from S0 to S3 will be compared between groups.
Measured: Baseline (Day 1) to Immediately After Intervention (Day 1)
Secondary outcomes (1)
Postoperative pain levels measured using the Visual Analog Scale (VAS, 0-100)
Postoperative pain intensity will be measured using the Visual Analog Scale (VAS), a 100-mm line ranging from 0 to 100, where 0 represents "no pain" and 100 represents "worst imaginable pain." Higher scores indicate worse pain. Participants will record their pain levels at each scheduled assessment time point.
Measured: 6 hours, 12 hours, 24 hours, Day 3, Day 5, and Day 7 after treatment.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Dec 2025
- Study start1 Jun 2025
- Primary completion7 Nov 2025
- Study completionMar 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Root Canal InfectionStudies of the same condition, open and under way.
- More trials run by Ataturk UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Participants will be randomly assigned into two parallel groups (experimental and control) and will receive the allocated intervention only. Each participant will remain in the assigned group for the duration of the study.
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 50 participants (actual)
Sponsor and investigators
- Lead sponsor
- Ataturk University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, AZİZ ŞAHİN ERDOĞAN, Ataturk University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07266233
- Sponsor's protocol ID
- AU-DHF-ASE-01
- Status last verified
- Dec 2025
- First submitted
- 16 Nov 2025
- Last updated
- 5 Dec 2025
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Er Karaoglu G, Ugur Ydin Z, Erdonmez D, Gol C, Durmus M. Efficacy of antimicrobial photodynamic therapy administered using methylene blue, toluidine blue and tetra 2-mercaptopyridine substituted zinc phthalocyanine in root canals contaminated with Enterococcusaecalis. Photodiagnosis Photodyn Ther. 2020 Dec;32:102038. doi: 10.1016/j.pdpdt.2020.102038. Epub 2020 Oct 1.
PubMed 33010484Mozayeni MA, Vatandoost F, Asnaashari M, Shokri M, Azari-Marhabi S, Asnaashari N. Comparing the Efficacy of Toluidine Blue, Methylene Blue and Curcumin in Photodynamic Therapy Against Enterococcus faecalis. J Lasers Med Sci. 2020 Fall;11(Suppl 1):S49-S54. doi: 10.34172/jlms.2020.S8. Epub 2020 Dec 30.
PubMed 33995969
Study at a glance
From the registry record, last updated by the sponsor on 5 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of the Antibacterial Activity and Postoperative Pain Outcomes of Photodynamic Therapy Using Toluidine Blue
- ClinicalTrials.gov ID
- NCT07266233
- Acronym / sponsor ID
- AU-DHF-ASE-01
- Conditions
- Root Canal Infection
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 50 participants (actual)
- Lead sponsor
- Ataturk UniversityUniversity, hospital or other
- Study start
- 1 Jun 2025 (actual)
- Primary completion
- 7 Nov 2025 (actual)
- Study completion
- Mar 2026 (estimated)
- First posted
- 5 Dec 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This clinical study aims to evaluate the antimicrobial effectiveness and postoperative pain outcomes of photodynamic therapy using Toluidine Blue O as an adjunct to conventional root canal treatment in patients diagnosed with symptomatic irreversible pulpitis. Photodynamic therapy is a non-invasive light-activated disinfection method, and this study will compare its performance with standard endodontic treatment protocols. The results are expected to provide clinical evidence regarding its potential benefits in reducing intracanal bacterial load and improving postoperative patient comfort.
Detailed description
This randomized clinical study is designed to investigate the antimicrobial effectiveness and postoperative pain outcomes of photodynamic therapy (PDT) using toluidine blue O (TBO) as an adjunct to conventional root canal treatment in single-rooted teeth with necrotic pulps. The rationale for this research is based on the persistent difficulty of achieving complete microbial elimination from the root canal system using standard chemomechanical preparation alone. Toluidine blue O-mediated PDT has been proposed as a minimally invasive disinfection method capable of producing reactive oxygen species after activation with visible light, thereby enhancing microbial reduction beyond that achieved by irrigation protocols.
The study employs a standardized protocol in which intracanal microbiological sampling is conducted at four predefined stages to monitor changes in microbial load throughout treatment. All samples are stored and analyzed using real-time quantitative polymerase chain reaction (qPCR), which allows sensitive detection and quantification of bacterial DNA. This molecular approach offers advantages over culture-based methods by identifying uncultivable or low-abundance bacterial species, providing a more comprehensive evaluation of the antimicrobial effect of PDT.
In the experimental group, photodynamic therapy is performed by introducing a 0.1 mg/mL toluidine blue O solution into the prepared root canal, followed by activation with a 630-nm LED light source. The choice of this wavelength corresponds to the absorption peak of TBO and optimizes energy transfer for singlet oxygen production. A sham procedure is used in the control group to maintain participant masking and ensure methodological consistency. Both groups receive identical chemomechanical preparation and irrigation procedures prior to the assigned intervention.
Pain assessment during the postoperative period is performed using a validated visual analog scale (VAS), providing continuous measurement of patient-reported discomfort during the first week after treatment. The integration of molecular microbiology with clinical pain evaluation allows a combined assessment of both biological and patient-centered outcomes. This study is expected to contribute new in-vivo evidence on the potential benefits of toluidine blue O-based PDT as an adjunctive disinfection method in endodontic therapy.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
- Model description
- Participants will be randomly assigned into two parallel groups (experimental and control) and will receive the allocated intervention only. Each participant will remain in the assigned group for the duration of the study.
| Arm | Type | Receives |
|---|---|---|
| Control Group (Sham PDT) | Placebo comparator | Procedure: Sham Photodynamic TherapyParticipants in this arm will receive the standard root canal irrigation protocol using 2.5% sodium hypochlorite and 17% EDTA. A sham photodynamic procedure will be performed by positioning the LED device near the tooth without light activation to simulate photodynamic therapy conditions. No Toluidine Blue O will be applied, and no active light irradiation will be performed |
| Experimental Group (PDT) | Experimental | Drug: Toluidine Blue O (0.1 mg/mL), Device: 630-nm LED Light Device, Procedure: Photodynamic Therapy (PDT)Participants in this arm will receive the standard root canal irrigation protocol followed by adjunctive photodynamic therapy. A 0.1 mg/mL Toluidine Blue O solution will be delivered into the canal and activated with a 630-nm LED light using an optical fiber for 60 seconds. This procedure will be performed after instrumentation and prior to final assessment sampling. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Patients aged between 18 and 65 years
- Presence of asymptomatic apical periodontitis with necrotic pulp in single-rooted maxillary or mandibular incisors, canines, or premolars
- Periapical Index (PAI) score ≥ 2
- Patients classified as ASA I (American Society of Anesthesiologists Physical Status Classification)
- Preoperative pain score < 50 on the Visual Analog Scale (VAS)
Key exclusion criteria (9 listed)
- Multi-rooted teeth
- Patients classified as ASA II or higher
- Pregnant women or those with suspected pregnancy
- Root canal curvature greater than 25° according to the Schilder method
- Patients diagnosed with generalized periodontitis
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Toluidine Blue O (0.1 mg/mL)A 0.1 mg/mL toluidine blue O solution used as the photosensitizer for photodynamic therapy. The solution is placed into the root canal prior to 630-nm LED irradiation for activation. | Drug | Experimental Group (PDT) |
| 630-nm LED Light DeviceA light-emitting diode device delivering 630-nm wavelength used to activate toluidine blue O during photodynamic therapy. The device is positioned near the tooth for 60 seconds. | Device | Experimental Group (PDT) |
| Photodynamic Therapy (PDT)Application of 0.1 mg/mL toluidine blue O into the root canal, followed by activation with a 630-nm LED light source for 60 seconds as part of the experimental disinfection protocol. | Procedure or surgery | Experimental Group (PDT) |
| Sham Photodynamic TherapyPlacebo photodynamic procedure in which the LED device is positioned similarly but activated without delivering light energy; no toluidine blue O is applied. | Procedure or surgery | Control Group (Sham PDT) |
Primary outcome
Reduction in intracanal bacterial load measured by quantitative PCR (qPCR)
Time frame: Baseline (Day 1) to Immediately After Intervention (Day 1)
Intracanal bacterial load will be quantified using real-time quantitative polymerase chain reaction (qPCR). Samples will be collected at four predefined sampling points (S0-S3) using sterile #30 paper points inserted into the canal for 30 seconds. S0 (Baseline): After isolation and disinfection, before instrumentation S1: After access cavity preparation and working length determination S2: After root canal instrumentation S3 (Post-Intervention): After final irrigation protocol and photodynamic therapy (or sham procedure) Changes in bacterial DNA concentration (copy number/µL) from S0 to S3 will be compared between groups.
1 secondary outcome
Postoperative pain levels measured using the Visual Analog Scale (VAS, 0-100)
Time frame: 6 hours, 12 hours, 24 hours, Day 3, Day 5, and Day 7 after treatment.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Dec 2025.
- Background: PubMed 33010484Er Karaoglu G, Ugur Ydin Z, Erdonmez D, Gol C, Durmus M. Efficacy of antimicrobial photodynamic therapy administered using methylene blue, toluidine blue and tetra 2-mercaptopyridine substituted zinc phthalocyanine in root canals contaminated with Enterococcusaecalis. Photodiagnosis Photodyn Ther. 2020 Dec;32:102038. doi: 10.1016/j.pdpdt.2020.102038. Epub 2020 Oct 1.
- Background: PubMed 33995969Mozayeni MA, Vatandoost F, Asnaashari M, Shokri M, Azari-Marhabi S, Asnaashari N. Comparing the Efficacy of Toluidine Blue, Methylene Blue and Curcumin in Photodynamic Therapy Against Enterococcus faecalis. J Lasers Med Sci. 2020 Fall;11(Suppl 1):S49-S54. doi: 10.34172/jlms.2020.S8. Epub 2020 Dec 30.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Toluidine Blue O (0.1 mg/mL), 630-nm LED Light Device and Photodynamic Therapy (PDT) in people with Root Canal Infection, run by Ataturk University at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 5 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Reduction in intracanal bacterial load measured by quantitative PCR (qPCR) (time frame: Baseline (Day 1) to Immediately After Intervention (Day 1)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07266233, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Dec 2025.