Table 2. Summary of the methodology and results of studies for healing of apical periodontitis (8 studies total).
| Study | Year | Experimental groups & irrigants used | Outcome measures | Key findings | |
|---|---|---|---|---|---|
| Liang et al. [43] | 2013 | ⋄ Syringe needle irrigation (3 × 2 mL 5.25% NaOCl with 10 sec in canal without agitation; final irrigation time 60 sec) | ⋄ Presence of radiographic periapical lesion | ⋄ No significant difference between ultrasonically activated irrigation and syringe irrigation in periapical healing. | |
| ⋄ Ultrasonically activated irrigation (3 × 2mL 5.25% NaOCl with 10 sec of activation; final irrigation time 60 sec) | ⋄ Periapical radiograph and CBCT (lesion area and volume) | ||||
| ▪ Absence | |||||
| ▪ Reduction of radiolucency | |||||
| ▪ Enlargement of radiolucency | |||||
| ▪ Uncertain | |||||
| Tang et al. [44] | 2015 | ⋄ Ultrasonically activated irrigation (2.5% NaOCl) | ⋄ Presence of radiographic periapical lesion | ⋄ No significant difference between all groups in healing after 6 months and 12 months. | |
| ⋄ Ultrasonically activated irrigation (silver ion antibacterial solution) | ⋄ Periapical radiograph (PAI score 1–5) | ||||
| ⋄ Syringe needle irrigation (2.5% NaOCl) | |||||
| Cohenca et al. [45] | 2015 | ⋄ Apical negative pressure (30 sec 5.25% NaOCl, 30 sec 17% EDTA, 30 sec 5.25% NaOCl) | ⋄ Dog teeth, experimentally induced periapical lesions | ⋄ All groups had similar periapical response. | |
| ⋄ Ultrasonically activated irrigation (30 sec 5.25% NaOCl + 20 sec of activation; 30 sec 17% EDTA + 20 sec of activation; 30 sec 5.25% NaOCl + 20 sec of activation) | ⋄ Presence of radiographic periapical lesion | ⋄ Apical negative pressure group had the mildest infiltration of inflammatory cells. | |||
| ⋄ Syringe needle irrigation (30 sec of 5.25% NaOCl, 30 sec of 17% EDTA, 30 sec of 5.25% NaOCl) | ⋄ Periapical radiograph (lesion area) | ||||
| ⋄ Histology (conventional & fluorescence microscopy & staining) | |||||
| ▪ Thickness of PDL: score 1–4 | |||||
| ▪ Inflammatory infiltration: score 1–4 | |||||
| ▪ Resorption process of the mineralized tissue: score 1–2 (presence or absence) | |||||
| De Jesus et al. [46] | 2019 | ⋄ Apical negative pressure (30 sec 5.25% NaOCl; 30 sec 17% EDTA; 30 sec 5.25% NaOCl) | ⋄ Dog teeth, experimentally induced periapical lesions | ⋄ No significant difference between the groups; repair of apical periodontitis occurred in up to 60% of cases regardless of irrigation protocol used. | |
| ⋄ Ultrasonically activated irrigation (30 sec 5.25% NaOCl + 20 sec of activation; 30 sec 17% EDTA + 20 sec of activation; 30 sec 5.25% NaOCl + 20 sec of activation) | ⋄ Presence of radiographic periapical lesion | ||||
| ⋄ Syringe needle irrigation (30 sec of 5.25% NaOCl; 30 sec of 17% EDTA; 30 sec of 5.25% NaOCl) | ⋄ Periapical radiograph (PAI score 1–5) | ||||
| ⋄ Immunohistochemistry | |||||
| ▪ Tumor necrosis factor (TNF-α) | |||||
| ▪ Osteopontin (OPN) | |||||
| ▪ Interleukin 1α (IL-1α) | |||||
| Sigurdsson et al. [47] | 2016 | ⋄ GentleWave (3% NaOCl, distilled water rinse; 8% EDTA; 30 sec final distilled water rinse; 2 min 8% EDTA; 15 sec distilled water rinse) | ⋄ Presence of radiographic periapical lesion | ⋄ GentleWave resulted in 97.4% success rate of healing. | |
| ⋄ Periapical radiograph (PAI score 1–5) | |||||
| Sigurdsson et al. [48] | 2016 | ⋄ GentleWave (3% NaOCl, distilled water rinse; 8% EDTA; 30 sec final distilled water rinse; 2 min 8% EDTA; 15 sec distilled water rinse) | ⋄ Presence of radiographic periapical lesion | ⋄ GentleWave resulted in 97.3% success rate of healing. | |
| ⋄ Periapical radiograph (PAI score 1–5) | |||||
| Sigurdsson et al. [49] | 2018 | ⋄ GentleWave (3% NaOCl, distilled water rinse; 8% EDTA; 30 sec final distilled water rinse; 2 min 8% EDTA; 15 sec distilled water rinse) | ⋄ Presence of radiographic periapical lesion | ⋄ GentleWave resulted in 97.7% success rate of healing. | |
| ⋄ Periapical radiograph (PAI score 1–5) | ⋄ 43 out of 44 were completely functional. | ||||
| Martins et al. [50] | 2013 | ⋄ Syringe needle irrigation + Ca(OH)2 (1st appt: 5 mL 3% NaOCl during instrumentation, Ca(OH)2 dressing; 2nd appt: 5 mL 3% NaOCl) | ⋄ Presence of radiographic periapical lesion | ⋄ No significant differences in periapical healing between the groups. | |
| ⋄ Er,Cr:YSGG (1st appt: 2 mL saline during instrumentation, 4 times irradiation with 2 with canals filled with distilled water, 2 in dry condition; 2nd appt: repeat irradiation procedures, 5 mL saline rinse 1 min) | ⋄ Periapical radiograph (PAI score 1–5) | ||||
NaOCl, sodium hypochlorite; CBCT, cone beam computed tomography; EDTA, ethylenediaminetetraacetic acid; PAI, periapical index; Er,Cr:YSGG, Erbium, Chromium doped Yttrium Scandium Gallium Garnet.