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

University of Nove de Julho7 enrolled

Overview

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.

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

Interventions

Conventional Endodontic TreatmentPROCEDURE

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.

Antimicrobial Photodynamic TherapyPROCEDURE

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.

Eligibility

Sex: ALLMin age: 2 YearsMax age: 5 Years

Medical Language ↔ Plain English

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.

Outcomes

Primary Outcomes

Change in Intracanal Microbial Load From Baseline to Immediately Post-intervention

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.

Time frame: Baseline and immediately post-intervention on Day 0

Secondary Outcomes

Number of Treated Teeth With Clinical Signs or Symptoms

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.

Time frame: 7 days, 1 month, and 3 months

Number of Treated Teeth With a Periapical or Periradicular Lesion

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.

Time frame: 1 month and 3 months.

Number of Treated Teeth Without Radiographic Worsening

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.

Time frame: 1 month and 3 months

Number of Treated Teeth With Pathological Root Resorption

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.