Effect of a novel laser-initiated photoacoustic activation of a solvent or sodium hypochlorite in the removal of filling remnants after retreatment of curved root canals

• Published in: Photodiagnosis and photodynamic therapy 2021-12, Vol.36, p.102535-102535, Article 102535
• Main Authors: Bago, Ivona, Plotino, Gianluca, Katić, Marko, Ferenac, Adriana, Petričević, Gabrijela Kapetanović, Gabrić, Dragana, Anić, Ivica
• Format: Article
• Language: English
• Subjects: Activation; Dental Pulp Cavity; Filling remnants; Lasers, Solid-State; Photochemotherapy - methods; Photosensitizing Agents; Retreatment; Root Canal Filling Materials; Root Canal Preparation; Sodium Hypochlorite; Solvent; Solvents
• ISSN: 1572-1000; 1873-1597
• DOI: 10.1016/j.pdpdt.2021.102535

•Using micro-CT to evaluate the efficacy of a novel laser activated irrigation in the removal of intracanal filling remnants.•The SWEEPS® was more effective than PUI, when used in combination with NaOCl, in the removal of filling remnants during root canal retreatment.•Additional activated irrigation of root canal with a solvent after the retreatment improved the removal of filling remnants from curved root canal. This study aimed to evaluate the effect of Er:YAG laser-initiated shockwave-enhanced emission of photoacoustic streaming (SWEEPS®) and passive ultrasonic irrigation (PUI) combining thymol-based solvent or sodium hypochlorite (NaOCl) in the removal of filling remnants from curved canals. Forty-eight curved root canals were instrumented and filled with an epoxy-resin-based sealer and gutta-percha. The canals were retreated with a Wave One Gold primary file (tip size 25; variable taper) and sodium hypochlorite (NaOCl). After the retreatment, the samples were randomly divided into four groups according to the additional irrigation protocol: PUI/NaOCl, PUI/solvent, SWEEPS®/NaOCl or SWEEPS®/solvent. The volume of filling material in root canal was measured after root canal filling, after mechanical retreatment, after final irrigation protocol and after additional irrigation protocol, using micro-CT. The results were analyzed using Kruskal-Wallis test with the post-hoc Mann-Whitney U test and Wilcoxon test (α=0.05). In the PUI group, irrigation with the solvent or NaOCl resulted in similar filling reduction (p = 0.224). In the SWEEPS® group, irrigation with NaOCl resulted in a significantly greater filling reduction compared to the solvent (p = 0.021). The SWEEPS®/NaOCl group was more effective than the PUI/NaOCl group (p = 0.008). No significant differences were found between PUI/solvent and SWEEPS® groups (p>0.05) and PUI/NaOCl and SWEEPS®/solvent group (p>0.05). Although all tested protocols improved the removal of filling remnants from curved root canal, the SWEEPS® was more successful than PUI when NaOCl was used. Both tested techniques showed similar efficacy when in combination with the solvent. [Display omitted]