Trial Outcomes & Findings for Effects of Different Irrigation Activation Techniques on the Healing of Large Periapical Lesions (NCT NCT06991803)

Results Overview

Post-endodontic treatment, a reduction in the diameter of the periapical lesion may be observed, or the lesion may exhibit complete radiographic resolution. the largest dimension obtained was recorded as the preoperative lesion diameter

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

132 participants

Primary outcome timeframe

1 year from completion of treatment to follow-up

Results posted on

2025-12-24

Participant Flow

Out of 150 patients aged 18 years and over, a total of 18 patients who refused to participate or did not meet the inclusion criteria were excluded from the study, and 132 patients were included. 14 patients did not participate in the follow-up process. 118 patients were analyzed.

Participant milestones

Participant milestones
Measure	Group 1 (MDA) After the root canal was filled with irrigation solution, a gutta-percha cone compatible with the master file was positioned 1 mm behind the working length and moved up and down with 100 strokes/minute for activation. root canal treatment and irrigation activation: After the teeth were isolated with a rubber dam, the endodontic access cavity was opened. Then, #10-15 K-type hand files were inserted into the canals, and after determining point 0.0 with the electronic apex locator, the working length was determined to be 0.5 mm shorter than this point and confirmed radiographically. When a discrepancy was observed, the apex locator was considered correct. The root canals were prepared with ProTaper Next up to 3 sizes larger than the initial diameter via a torque-controlled endodontic motor in 300 rpm/2-5.2 Ncm rotation mode. Between each file, the canals were irrigated with 5 ml of 2.5% NaOCl. In retreatment cases, after opening the access cavity under rubber dam isolation, the guta percha was removed with RT files, and the rest of the procedure was performed in the same manner as for primary root canal treatment.	Group 2 (Sonic Activation) Sonic activation was performed via the Easydo Activator device (EA; Easyinsmile (Weixiaomeichi, Changsha, China). While the solution was present in the canal, the needle tip of the device was placed in the canal 2 mm behind the determined working length, and the solutions were activated at the recommended power setting. root canal treatment and irrigation activation: After the teeth were isolated with a rubber dam, the endodontic access cavity was opened. Then, #10-15 K-type hand files were inserted into the canals, and after determining point 0.0 with the electronic apex locator, the working length was determined to be 0.5 mm shorter than this point and confirmed radiographically. When a discrepancy was observed, the apex locator was considered correct. The root canals were prepared with ProTaper Next up to 3 sizes larger than the initial diameter via a torque-controlled endodontic motor in 300 rpm/2-5.2 Ncm rotation mode. Between each file, the canals were irrigated with 5 ml of 2.5% NaOCl. In retreatment cases, after opening the access cavity under rubber dam isolation, the guta percha was removed with RT files, and the rest of the procedure was performed in the same manner as for primary root canal treatment.	Group 3 (PUI) Solutions were activated via ultrasonic tips (mode:E, setting:6) (DTE, Guilin Woodpecker Co., Guilin, Guangxi, China) and an ultrasonic device (DTE S6 Led, Guilin Woodpecker Co., Guilin, Guangxi, China). An ultrasonic tip one size smaller than the master apical file was used 2 mm behind the working length without contacting the walls. root canal treatment and irrigation activation: After the teeth were isolated with a rubber dam, the endodontic access cavity was opened. Then, #10-15 K-type hand files were inserted into the canals, and after determining point 0.0 with the electronic apex locator, the working length was determined to be 0.5 mm shorter than this point and confirmed radiographically. When a discrepancy was observed, the apex locator was considered correct. The root canals were prepared with ProTaper Next up to 3 sizes larger than the initial diameter via a torque-controlled endodontic motor in 300 rpm/2-5.2 Ncm rotation mode. Between each file, the canals were irrigated with 5 ml of 2.5% NaOCl. In retreatment cases, after opening the access cavity under rubber dam isolation, the guta percha was removed with RT files, and the rest of the procedure was performed in the same manner as for primary root canal treatment.	Group 4 (PIPS) A Fotona Er:YAG laser device (LightWalker Fotona, Ljubljana, Slovenia) was used for activation. A special conical and radial fiber tip (PIPS 300/14, Fotona) was placed in the coronal part of the pulp chamber, and the irrigation solutions in the canal were activated in SSP mode (50 μs, 0.3 W, 15 Hz and 20 mJ) with the air and water settings turned off. root canal treatment and irrigation activation: After the teeth were isolated with a rubber dam, the endodontic access cavity was opened. Then, #10-15 K-type hand files were inserted into the canals, and after determining point 0.0 with the electronic apex locator, the working length was determined to be 0.5 mm shorter than this point and confirmed radiographically. When a discrepancy was observed, the apex locator was considered correct. The root canals were prepared with ProTaper Next up to 3 sizes larger than the initial diameter via a torque-controlled endodontic motor in 300 rpm/2-5.2 Ncm rotation mode. Between each file, the canals were irrigated with 5 ml of 2.5% NaOCl. In retreatment cases, after opening the access cavity under rubber dam isolation, the guta percha was removed with RT files, and the rest of the procedure was performed in the same manner as for primary root canal treatment.	Group 5 (SWEEPS) A Fotona Er:YAG laser device (SWEEPS 600, Fotona) with an 8.5 mm long and 600 µm diameter tapered fiber tip was used for activation. The device was set to AutoSWEEPS mode with two ultrashort micropulses (25 μs) continuously changing at 0.3 W, 20 mJ, and 15 Hz. The tip was placed in the pulp chamber, and the solution was activated with the air and water settings turned off. root canal treatment and irrigation activation: After the teeth were isolated with a rubber dam, the endodontic access cavity was opened. Then, #10-15 K-type hand files were inserted into the canals, and after determining point 0.0 with the electronic apex locator, the working length was determined to be 0.5 mm shorter than this point and confirmed radiographically. When a discrepancy was observed, the apex locator was considered correct. The root canals were prepared with ProTaper Next up to 3 sizes larger than the initial diameter via a torque-controlled endodontic motor in 300 rpm/2-5.2 Ncm rotation mode. Between each file, the canals were irrigated with 5 ml of 2.5% NaOCl. In retreatment cases, after opening the access cavity under rubber dam isolation, the guta percha was removed with RT files, and the rest of the procedure was performed in the same manner as for primary root canal treatment.	Control Group (Conventional Syringe Irrigation) In this group, the traditional syringe method was used for final irrigation of the root canals. The canals were irrigated with 6 mL of 17% EDTA solution, 2 mL of saline and, finally, 6 mL of 2.5% NaOCl, and a 30-gauge perforated irrigation needle placed 1-2 mm shorter than the working length was used. During irrigation, 1-2 mm updown movements were made with a constant low pressure. root canal treatment and irrigation activation: After the teeth were isolated with a rubber dam, the endodontic access cavity was opened. Then, #10-15 K-type hand files were inserted into the canals, and after determining point 0.0 with the electronic apex locator, the working length was determined to be 0.5 mm shorter than this point and confirmed radiographically. When a discrepancy was observed, the apex locator was considered correct. The root canals were prepared with ProTaper Next up to 3 sizes larger than the initial diameter via a torque-controlled endodontic motor in 300 rpm/2-5.2 Ncm rotation mode. Between each file, the canals were irrigated with 5 ml of 2.5% NaOCl. In retreatment cases, after opening the access cavity under rubber dam isolation, the guta percha was removed with RT files, and the rest of the procedure was performed in the same manner as for primary root canal treatment.
Overall Study STARTED	22	22	22	22	22	22
Overall Study COMPLETED	22	18	22	19	20	17
Overall Study NOT COMPLETED	0	4	0	3	2	5

Reasons for withdrawal

Reasons for withdrawal
Measure	Group 1 (MDA) After the root canal was filled with irrigation solution, a gutta-percha cone compatible with the master file was positioned 1 mm behind the working length and moved up and down with 100 strokes/minute for activation. root canal treatment and irrigation activation: After the teeth were isolated with a rubber dam, the endodontic access cavity was opened. Then, #10-15 K-type hand files were inserted into the canals, and after determining point 0.0 with the electronic apex locator, the working length was determined to be 0.5 mm shorter than this point and confirmed radiographically. When a discrepancy was observed, the apex locator was considered correct. The root canals were prepared with ProTaper Next up to 3 sizes larger than the initial diameter via a torque-controlled endodontic motor in 300 rpm/2-5.2 Ncm rotation mode. Between each file, the canals were irrigated with 5 ml of 2.5% NaOCl. In retreatment cases, after opening the access cavity under rubber dam isolation, the guta percha was removed with RT files, and the rest of the procedure was performed in the same manner as for primary root canal treatment.	Group 2 (Sonic Activation) Sonic activation was performed via the Easydo Activator device (EA; Easyinsmile (Weixiaomeichi, Changsha, China). While the solution was present in the canal, the needle tip of the device was placed in the canal 2 mm behind the determined working length, and the solutions were activated at the recommended power setting. root canal treatment and irrigation activation: After the teeth were isolated with a rubber dam, the endodontic access cavity was opened. Then, #10-15 K-type hand files were inserted into the canals, and after determining point 0.0 with the electronic apex locator, the working length was determined to be 0.5 mm shorter than this point and confirmed radiographically. When a discrepancy was observed, the apex locator was considered correct. The root canals were prepared with ProTaper Next up to 3 sizes larger than the initial diameter via a torque-controlled endodontic motor in 300 rpm/2-5.2 Ncm rotation mode. Between each file, the canals were irrigated with 5 ml of 2.5% NaOCl. In retreatment cases, after opening the access cavity under rubber dam isolation, the guta percha was removed with RT files, and the rest of the procedure was performed in the same manner as for primary root canal treatment.	Group 3 (PUI) Solutions were activated via ultrasonic tips (mode:E, setting:6) (DTE, Guilin Woodpecker Co., Guilin, Guangxi, China) and an ultrasonic device (DTE S6 Led, Guilin Woodpecker Co., Guilin, Guangxi, China). An ultrasonic tip one size smaller than the master apical file was used 2 mm behind the working length without contacting the walls. root canal treatment and irrigation activation: After the teeth were isolated with a rubber dam, the endodontic access cavity was opened. Then, #10-15 K-type hand files were inserted into the canals, and after determining point 0.0 with the electronic apex locator, the working length was determined to be 0.5 mm shorter than this point and confirmed radiographically. When a discrepancy was observed, the apex locator was considered correct. The root canals were prepared with ProTaper Next up to 3 sizes larger than the initial diameter via a torque-controlled endodontic motor in 300 rpm/2-5.2 Ncm rotation mode. Between each file, the canals were irrigated with 5 ml of 2.5% NaOCl. In retreatment cases, after opening the access cavity under rubber dam isolation, the guta percha was removed with RT files, and the rest of the procedure was performed in the same manner as for primary root canal treatment.	Group 4 (PIPS) A Fotona Er:YAG laser device (LightWalker Fotona, Ljubljana, Slovenia) was used for activation. A special conical and radial fiber tip (PIPS 300/14, Fotona) was placed in the coronal part of the pulp chamber, and the irrigation solutions in the canal were activated in SSP mode (50 μs, 0.3 W, 15 Hz and 20 mJ) with the air and water settings turned off. root canal treatment and irrigation activation: After the teeth were isolated with a rubber dam, the endodontic access cavity was opened. Then, #10-15 K-type hand files were inserted into the canals, and after determining point 0.0 with the electronic apex locator, the working length was determined to be 0.5 mm shorter than this point and confirmed radiographically. When a discrepancy was observed, the apex locator was considered correct. The root canals were prepared with ProTaper Next up to 3 sizes larger than the initial diameter via a torque-controlled endodontic motor in 300 rpm/2-5.2 Ncm rotation mode. Between each file, the canals were irrigated with 5 ml of 2.5% NaOCl. In retreatment cases, after opening the access cavity under rubber dam isolation, the guta percha was removed with RT files, and the rest of the procedure was performed in the same manner as for primary root canal treatment.	Group 5 (SWEEPS) A Fotona Er:YAG laser device (SWEEPS 600, Fotona) with an 8.5 mm long and 600 µm diameter tapered fiber tip was used for activation. The device was set to AutoSWEEPS mode with two ultrashort micropulses (25 μs) continuously changing at 0.3 W, 20 mJ, and 15 Hz. The tip was placed in the pulp chamber, and the solution was activated with the air and water settings turned off. root canal treatment and irrigation activation: After the teeth were isolated with a rubber dam, the endodontic access cavity was opened. Then, #10-15 K-type hand files were inserted into the canals, and after determining point 0.0 with the electronic apex locator, the working length was determined to be 0.5 mm shorter than this point and confirmed radiographically. When a discrepancy was observed, the apex locator was considered correct. The root canals were prepared with ProTaper Next up to 3 sizes larger than the initial diameter via a torque-controlled endodontic motor in 300 rpm/2-5.2 Ncm rotation mode. Between each file, the canals were irrigated with 5 ml of 2.5% NaOCl. In retreatment cases, after opening the access cavity under rubber dam isolation, the guta percha was removed with RT files, and the rest of the procedure was performed in the same manner as for primary root canal treatment.	Control Group (Conventional Syringe Irrigation) In this group, the traditional syringe method was used for final irrigation of the root canals. The canals were irrigated with 6 mL of 17% EDTA solution, 2 mL of saline and, finally, 6 mL of 2.5% NaOCl, and a 30-gauge perforated irrigation needle placed 1-2 mm shorter than the working length was used. During irrigation, 1-2 mm updown movements were made with a constant low pressure. root canal treatment and irrigation activation: After the teeth were isolated with a rubber dam, the endodontic access cavity was opened. Then, #10-15 K-type hand files were inserted into the canals, and after determining point 0.0 with the electronic apex locator, the working length was determined to be 0.5 mm shorter than this point and confirmed radiographically. When a discrepancy was observed, the apex locator was considered correct. The root canals were prepared with ProTaper Next up to 3 sizes larger than the initial diameter via a torque-controlled endodontic motor in 300 rpm/2-5.2 Ncm rotation mode. Between each file, the canals were irrigated with 5 ml of 2.5% NaOCl. In retreatment cases, after opening the access cavity under rubber dam isolation, the guta percha was removed with RT files, and the rest of the procedure was performed in the same manner as for primary root canal treatment.
Overall Study Lost to Follow-up	0	4	0	3	2	5

Baseline Characteristics

Race and Ethnicity were not collected from any participant.

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Control Group (Conventional Syringe Irrigation) n=17 Participants In this group, the traditional syringe method was used for final irrigation of the root canals. The canals were irrigated with 6 mL of 17% EDTA solution, 2 mL of saline and, finally, 6 mL of 2.5% NaOCl, and a 30-gauge perforated irrigation needle placed 1-2 mm shorter than the working length was used. During irrigation, 1-2 mm updown movements were made with a constant low pressure.	Group 1 (MDA) n=22 Participants After the root canal was filled with irrigation solution, a gutta-percha cone compatible with the master file was positioned 1 mm behind the working length and moved up and down with 100 strokes/minute for activation.	Group 2 (Sonic Activation) n=18 Participants Sonic activation was performed via the Easydo Activator device (EA; Easyinsmile (Weixiaomeichi, Changsha, China). While the solution was present in the canal, the needle tip of the device was placed in the canal 2 mm behind the determined working length, and the solutions were activated at the recommended power setting.	Group 3 (PUI) n=22 Participants Solutions were activated via ultrasonic tips (mode:E, setting:6) (DTE, Guilin Woodpecker Co., Guilin, Guangxi, China) and an ultrasonic device (DTE S6 Led, Guilin Woodpecker Co., Guilin, Guangxi, China). An ultrasonic tip one size smaller than the master apical file was used 2 mm behind the working length without contacting the walls.	Group 4 (PIPS) n=19 Participants A Fotona Er:YAG laser device (LightWalker Fotona, Ljubljana, Slovenia) was used for activation. A special conical and radial fiber tip (PIPS 300/14, Fotona) was placed in the coronal part of the pulp chamber, and the irrigation solutions in the canal were activated in SSP mode (50 μs, 0.3 W, 15 Hz and 20 mJ) with the air and water settings turned off.	Group 5 (SWEEPS) n=20 Participants A Fotona Er:YAG laser device (SWEEPS 600, Fotona) with an 8.5 mm long and 600 µm diameter tapered fiber tip was used for activation. The device was set to SWEEPS mode with two ultrashort micropulses (25 μs) continuously changing at 0.3 W, 20 mJ, and 15 Hz. The tip was placed in the pulp chamber, and the solution was activated with the air and water settings turned off.	Total n=118 Participants Total of all reporting groups
Pre-operative lesion diameter	3.01 mm2 STANDARD_DEVIATION 1.21 • n=17 Participants	2.79 mm2 STANDARD_DEVIATION 1.67 • n=22 Participants	3.11 mm2 STANDARD_DEVIATION 1.42 • n=18 Participants	3.17 mm2 STANDARD_DEVIATION 2.04 • n=22 Participants	2.96 mm2 STANDARD_DEVIATION 1.28 • n=19 Participants	2.43 mm2 STANDARD_DEVIATION 0.94 • n=20 Participants	2.91 mm2 STANDARD_DEVIATION 1.42 • n=118 Participants
Pre-operative PAI score	4.412 scores on a scale STANDARD_DEVIATION 0.507 • n=17 Participants	4.136 scores on a scale STANDARD_DEVIATION 0.834 • n=22 Participants	4.056 scores on a scale STANDARD_DEVIATION 0.802 • n=18 Participants	4.318 scores on a scale STANDARD_DEVIATION 0.568 • n=22 Participants	4.211 scores on a scale STANDARD_DEVIATION 0.787 • n=19 Participants	4.100 scores on a scale STANDARD_DEVIATION 0.641 • n=20 Participants	4.205 scores on a scale STANDARD_DEVIATION 0.689 • n=118 Participants
Age, Continuous	53.2 Years n=17 Participants	44.0 Years n=22 Participants	48.8 Years n=18 Participants	44.7 Years n=22 Participants	43.2 Years n=19 Participants	44.8 Years n=20 Participants	46.2 Years n=118 Participants
Sex: Female, Male Female	11 Participants n=17 Participants	7 Participants n=22 Participants	4 Participants n=18 Participants	11 Participants n=22 Participants	10 Participants n=19 Participants	12 Participants n=20 Participants	55 Participants n=118 Participants
Sex: Female, Male Male	6 Participants n=17 Participants	15 Participants n=22 Participants	14 Participants n=18 Participants	11 Participants n=22 Participants	9 Participants n=19 Participants	8 Participants n=20 Participants	63 Participants n=118 Participants
Race and Ethnicity Not Collected	—	—	—	—	—	—	0 Participants Race and Ethnicity were not collected from any participant.
Pre-operative fractal dimension	1.216 unitless STANDARD_DEVIATION 0.044 • n=17 Participants	1.23 unitless STANDARD_DEVIATION 0.04 • n=22 Participants	1.25 unitless STANDARD_DEVIATION 0.034 • n=18 Participants	1.235 unitless STANDARD_DEVIATION 0.049 • n=22 Participants	1.249 unitless STANDARD_DEVIATION 0.042 • n=19 Participants	1.216 unitless STANDARD_DEVIATION 0.025 • n=20 Participants	1.232 unitless STANDARD_DEVIATION 0.039 • n=118 Participants

PRIMARY outcome

Timeframe: 1 year from completion of treatment to follow-up

Post-endodontic treatment, a reduction in the diameter of the periapical lesion may be observed, or the lesion may exhibit complete radiographic resolution. the largest dimension obtained was recorded as the preoperative lesion diameter

Outcome measures

Outcome measures
Measure	Group 2 (Sonic Activation) n=18 Participants Sonic activation was performed via the Easydo Activator device (EA; Easyinsmile (Weixiaomeichi, Changsha, China). While the solution was present in the canal, the needle tip of the device was placed in the canal 2 mm behind the determined working length, and the solutions were activated at the recommended power setting.	Control Group (Conventional Syringe Irrigation) n=17 Participants In this group, the traditional syringe method was used for final irrigation of the root canals. The canals were irrigated with 6 mL of 17% EDTA solution, 2 mL of saline and, finally, 6 mL of 2.5% NaOCl, and a 30-gauge perforated irrigation needle placed 1-2 mm shorter than the working length was used. During irrigation, 1-2 mm updown movements were made with a constant low pressure.	Group 1 (MDA) n=22 Participants After the root canal was filled with irrigation solution, a gutta-percha cone compatible with the master file was positioned 1 mm behind the working length and moved up and down with 100 strokes/minute for activation.	Group 3 (PUI) n=22 Participants Solutions were activated via ultrasonic tips (mode:E, setting:6) (DTE, Guilin Woodpecker Co., Guilin, Guangxi, China) and an ultrasonic device (DTE S6 Led, Guilin Woodpecker Co., Guilin, Guangxi, China). An ultrasonic tip one size smaller than the master apical file was used 2 mm behind the working length without contacting the walls.	Group 4 (PIPS) n=19 Participants A Fotona Er:YAG laser device (LightWalker Fotona, Ljubljana, Slovenia) was used for activation. A special conical and radial fiber tip (PIPS 300/14, Fotona) was placed in the coronal part of the pulp chamber, and the irrigation solutions in the canal were activated in SSP mode (50 μs, 0.3 W, 15 Hz and 20 mJ) with the air and water settings turned off.	Group 5 (SWEEPS) n=20 Participants A Fotona Er:YAG laser device (SWEEPS 600, Fotona) with an 8.5 mm long and 600 µm diameter tapered fiber tip was used for activation. The device was set to SWEEPS mode with two ultrashort micropulses (25 μs) continuously changing at 0.3 W, 20 mJ, and 15 Hz. The tip was placed in the pulp chamber, and the solution was activated with the air and water settings turned off.
Post-operative Diameter of the Periapical Lesion	1.12 Post-operative lesion diameter- mm2 Standard Deviation 1.84	2.07 Post-operative lesion diameter- mm2 Standard Deviation 2.28	0.98 Post-operative lesion diameter- mm2 Standard Deviation 1.65	0.78 Post-operative lesion diameter- mm2 Standard Deviation 1.58	0.33 Post-operative lesion diameter- mm2 Standard Deviation 0.24	0.43 Post-operative lesion diameter- mm2 Standard Deviation 0.64

SECONDARY outcome

Timeframe: 1 year from completion of treatment to follow-up

Periapical status is evaluated radiographically using the Periapical Index (PAI), which scores lesions from 1 to 5 according to increasing radiographic appearance, helps to achieve consensus among dropping in categorizing lesions. In most studies utilizing the PAI, scores of 1 and 2 are classified as 'successful' or 'healed,' whereas scores of 3, 4, and 5 are categorized as 'unsuccessful' or 'non-healed.' Classifying PAI scores \<3 as healed and ≥3 as non-healed may facilitate communication between studies and the comparison of outcomes, particularly in follow-up studies; however, this approach may not provide detailed information regarding the progression of the disease. Lesion sizes on panoramic X-ray were classified according to the PAI classification. For each activation group, the mean PAI of participants was recorded as the group's PAI value in the data table.

Outcome measures

Outcome measures
Measure	Group 2 (Sonic Activation) n=18 Participants Sonic activation was performed via the Easydo Activator device (EA; Easyinsmile (Weixiaomeichi, Changsha, China). While the solution was present in the canal, the needle tip of the device was placed in the canal 2 mm behind the determined working length, and the solutions were activated at the recommended power setting.	Control Group (Conventional Syringe Irrigation) n=17 Participants In this group, the traditional syringe method was used for final irrigation of the root canals. The canals were irrigated with 6 mL of 17% EDTA solution, 2 mL of saline and, finally, 6 mL of 2.5% NaOCl, and a 30-gauge perforated irrigation needle placed 1-2 mm shorter than the working length was used. During irrigation, 1-2 mm updown movements were made with a constant low pressure.	Group 1 (MDA) n=22 Participants After the root canal was filled with irrigation solution, a gutta-percha cone compatible with the master file was positioned 1 mm behind the working length and moved up and down with 100 strokes/minute for activation.	Group 3 (PUI) n=22 Participants Solutions were activated via ultrasonic tips (mode:E, setting:6) (DTE, Guilin Woodpecker Co., Guilin, Guangxi, China) and an ultrasonic device (DTE S6 Led, Guilin Woodpecker Co., Guilin, Guangxi, China). An ultrasonic tip one size smaller than the master apical file was used 2 mm behind the working length without contacting the walls.	Group 4 (PIPS) n=19 Participants A Fotona Er:YAG laser device (LightWalker Fotona, Ljubljana, Slovenia) was used for activation. A special conical and radial fiber tip (PIPS 300/14, Fotona) was placed in the coronal part of the pulp chamber, and the irrigation solutions in the canal were activated in SSP mode (50 μs, 0.3 W, 15 Hz and 20 mJ) with the air and water settings turned off.	Group 5 (SWEEPS) n=20 Participants A Fotona Er:YAG laser device (SWEEPS 600, Fotona) with an 8.5 mm long and 600 µm diameter tapered fiber tip was used for activation. The device was set to SWEEPS mode with two ultrashort micropulses (25 μs) continuously changing at 0.3 W, 20 mJ, and 15 Hz. The tip was placed in the pulp chamber, and the solution was activated with the air and water settings turned off.
Post-operative Periapical Index (PAI) Score	1.778 scores on a scale Standard Deviation 1.215	2.647 scores on a scale Standard Deviation 1.272	2.000 scores on a scale Standard Deviation 0.976	1.864 scores on a scale Standard Deviation 0.941	1.421 scores on a scale Standard Deviation 0.507	1.400 scores on a scale Standard Deviation 0.754

OTHER_PRE_SPECIFIED outcome

Timeframe: 1 year from completion of treatment to follow-up

According to research, a high fractal dimension value indicates a more complex structure with fewer spaces between trabeculae, whereas a low fractal dimension value reflects a simpler structure with larger inter-trabecular spaces. The healing processes of lesions following root canal treatment can be objectively analyzed using the fractal analysis method, allowing for a quantitative evaluation of the degree of bone tissue healing and the remodeling of the trabecular architecture post-treatment.Fractal analysis (FA) was performed by an experienced oral and maxillofacial radiologist who was blinded to the activation method and used the fractal box counting method on panoramic radiographs. Images were processed in ImageJ through 8-bit conversion, Gaussian filtering, subtraction, thresholding, binarization, erosion-dilation, inversion, skeletonization, and fractal dimension calculation.