Efficiency of diode laser and ultrasonic-activated irrigation in retreatment of gutta percha and bioceramic sealer: An in vitro study

Evaluation of canal patency and cleanliness following retreatment of bioceramic sealer-obturated root canals using three different irrigant activation protocols

This study evaluated the effectiveness of three different irrigant activation techniques in cleaning and establishing patency during retreatment of root canals obturated with gutta-percha and bioceramic sealer. 60 extracted premolars with oval-shaped canals were instrumented and obturated with gutta-percha and EndosequenceBC sealer using the 'warm hydraulic condensation' technique. The teeth were retreated using Protaper Universal Retreatment and XP-Endo Shaper system and divided into four groups according to the irrigant activation protocol used: control, passive ultrasonic irrigation (PUI), Endovac irrigation (EVI) and XP-Endo Finisher R (XPFR). Apical patency was achieved in all the samples of the XPFR group (100%), which showed a significantly higher success rate compared with the control (73.3%) and EVI groups (73.3%) (p < 0.05). The scanning electron microscopic evaluation revealed significantly cleaner middle and apical third root canals in the PUI and XPFR groups compared with the control group (p < 0.05). These findings suggest that XPFR effectively cleans and establishes patency in root canals filled with bioceramic sealers.

Impact of LASER activated irrigation on the retrievability of Guttaflow bioseal (in-vitro study)

BACKGROUND

This study aimed to evaluate the efficiency of diode LASER activated irrigation in the removal of GuttaFlow Bioseal root canal filling material during retreatment.

MATERIALS AND SUBJECTS

Root canals of forty-five single-rooted human mandibular premolar teeth were prepared with ProTaper Universal rotary system and obturated with lateral condensation obturation technique using Gutta Percha and Roeko GuttaFlow Bioseal root canal sealer. All specimens were retreated with ProTaper Universal Retreatment System files then divided to three different groups according to the technique of activation of irrigation. Samples were sectioned, and the residual filling remnants were captured using digital camera attached to microscope. Data was collected by three different interpreters, to eliminate the subjectivity of the process, using the ImageJ Software. The mean value of the data was obtained and evaluated statistically. The significance level was set at P ≤ 0.05.

RESULTS

The remaining filling materials in the canals irrigated with ultrasonic activation (6.17 ± 1.42 at coronal level, 10.93 ± 1.91at middle level, and 14.58 ± 2.23 at apical level) were less than these irrigated with LASER activation (15.87 ± 3.78 at coronal level, 21.28 ± 4.44 at middle level, and 27.06 ± 2.68 at apical level). Maximum amount of remaining filling materials was present in the canals irrigated with passive side-vented syringe (23.07 ± 3.22 at coronal level, 38.09 ± 7.27 at middle level, and 34.24 ± 9.77 at apical level).

CONCLUSION

The activation of irrigation techniques used were incapable of complete removal of filling material at root canal walls.

The Efficacy of Er:YAG Laser-Activated Shock Wave-Enhanced Emission Photoacoustic Streaming Compared to Ultrasonically Activated Irrigation and Needle Irrigation in the Removal of Bioceramic Filling Remnants from Oval Root Canals-An Ex Vivo Study

The removal of filling material is important for successful root canal retreatment. The aim of the study was to compare the efficiency of two activated irrigation techniques, the shock wave-enhanced emission photoacoustic streaming (SWEEPS) mode of the Er:YAG laser and ultrasonically activated irrigation (UAI) and a conventional syringe-needle technique (SNI), in the removal of bioceramic sealer/gutta-percha during conventional retreatment in oval root canals. The study sample consisted of distal root canals of 42 extracted human mandibular molars, which were prepared using a ProTaper Next system up to size 40/0.06 and filled with bioceramic sealer using a single-cone obturation technique. The teeth were then re-treated with a Reciproc Blue RB40 file and 3% sodium hypochlorite solution. The prepared teeth were randomly divided into three groups (n = 14 per group) and subjected to one of the three irrigation methods. Micro-CT scans were performed at different stages to assess the amount of filling material after each retreatment phase. The results of the study showed that all the tested irrigation techniques reduced a statistically significant amount of the remnant filling material at retreatment (p < 0.05), and there were no statistically significant differences in efficacy between the three methods. All tested techniques had similar efficacy in the removal of the remaining filling remnants.

Evaluation of Dentinal Microcracks following Diode Laser- and Ultrasonic-Activated Removal of Bioceramic Material during Root Canal Retreatment

This study is aimed at evaluating the use of microcomputed tomography (micro-CT) analysis and the dentinal microcrack formation following retreatment of bioceramic sealer employing adjunct laser-activated irrigation and ultrasonic-activated irrigation. Thirty sound human single-canal teeth (n = 30) obturated using the single-cone technique with bioceramic sealer were retreated using nickel-titanium (NiTi) rotary files. The sample was randomly divided into three equal groups: group 1, the control group, was not subjected to further treatment; group 2 underwent ultrasonic activation of irrigants; group 3 underwent active irrigation with a diode laser (980 nm wavelength). Using micro-CT, the teeth were scanned before and after retreatment protocols. Two calibrated experienced observers viewed the cross-sectional images and calculated the number of dentinal defects. The presence of any crack or craze line on the external root surface or internal canal wall was counted. Data were analyzed using Friedman's two-way analysis of variance and Fisher's exact test. Statistical significance was set at p < 0.05. A significant increase occurred in the number of cracks post retreatment protocols, specifically in the coronal and middle canal thirds, compared to pre- and postinstrumentation (p = 0.0001). However, ultrasonic- or laser-activated irrigation did not result in a significant increase in the number of cracks (p = 0.345). NiTi rotary root canal retreatment was associated with a significant increase in dentinal microcracks. However, employing ultrasonic- or laser-activated irrigation as adjunct retreatment techniques did not reveal a significant increase in dentinal microcracks within the roots.