Potential of an Er:YAG Laser in the Removal of Calcium Hydroxide from Root Canals

Current Applications and Future Directions of Lasers in Endodontics: A Narrative Review

The utilization of lasers has been regarded as a novel technique for the purposes of clinical use in the dental field. Recently, numerous studies have been conducted on the potential applications of laser therapy in endodontics. Moreover, due to their ablation, penetrability, and disinfection capabilities, lasers have performed well with respect to endodontic treatments, including root canal treatment, vital pulp therapy (pulp capping and pulpotomy), dentinal hypersensitivity treatment, and management of dental pain related to pulp and periradicular disease. In particular, the superiorities of laser-aided pulp therapy are emphasized through condensed clinical controlled trials, and histological studies, in this review. Moreover, the ingenious use of laser applications with respect to aiding in the acceleration of root development and the extraction of foreign matters (i.e., broken files and fiber posts) in canals has quickly become the cutting-edge trend of current research. This review offers a summary and discussion of the current literature on all the aforementioned laser applications. Moreover, the characteristics of laser devices, including erbium lasers, neodymium-doped lasers, CO2 lasers, and diode lasers, are detailed and discussed here, providing useful references for laser application in endodontics. We also focus on the different wavelengths with respect to the lasers that are applied in endodontics. High-power lasers perform well as operative instruments; in addition, low-level lasers lead to the regulation of pulp inflammation, and the promotion of pulp healing. This narrative review provides a summary of the advanced applications of lasers in conjunction with various devices in the practice of endodontics, and aims to inspire innovative perspectives on lasers in the context of the treatment of dental diseases, especially pulp diseases, in the future.

The XP-Endo Finisher for the removal of calcium hydroxide paste from root canals and from the apical third

Background

The aim was to compare the efficacy of the passive ultrasonic irrigation PUI and the Xp-endo Finisher (FKG-Dentaire, La-Chaux-de-Fonds, Switzerland) in removing the calcium hydroxide paste from root canals and from the apical third.

Material and Methods

Sixty-eight root canals of single-rooted teeth were shaped using the BT-Race files (FKG-Dentaire, La-Chaux-de-Fonds, Switzerland). Ca(OH)2 was placed in all samples except for the negative control group (n=4). Remaining teeth were randomly divided into three groups: G1-Xp (n=30), G2-PUI (n=30) and the positive control group (n=4). Removal procedure consisted of three repeated one-minute-cycles. Samples were split longitudinally, photos of halves were taken at X6.4 magnification and were analyzed using the ImageJ-Software (The National Institutes of Health NIH, Bethesda, Maryland, USA) to calculate the percentage of surfaces with residual Ca(OH)2; the results were compared using the Wilcoxon-Mann Whitney test. Photos of the apical thirds were taken at X16 and X40 magnifications and were scored by two examiners from (0) to (4). Scores of the apical third were compared using the Fisher test.

Results

The Xp-endo Finisher removed completely the Ca(OH)2 dressing from four teeth (13.33%) whereas the PUI in one tooth (3.33%). The mean values of the remaining Ca(OH)2 were (2.1%, 3.6%) respectively and the difference was not significant (p= 0.195). Both examiners found the Xp-endo Finisher more efficient in the apical third and the difference was significant; p= (0.025, 0.047) respectively.

Conclusions

The Xp-endo Finisher showed a superiority over the PUI in removing the Ca(OH)2 from the apical third after 3 minutes of activation.

Key words:Calcium hydroxide removal, Passive ultrasonic irrigation, Xp-endo Finisher.

Comparison of different agitation methods for the removal of calcium hydroxide from the root canal: Scanning electron microscopy study

Aim:

This ex vivo study compared the efficiency of different irrigations systems to remove calcium hydroxide from root canal walls, especially from the apical third by using scanning electron microscopy (SEM).

Materials and Methods:

Eighty-four single-rooted teeth were divided into 4 groups of 20 teeth each, according to different irrigation protocols using a 30-gauge slot-tipped needle, ultrasonic irrigation system, erbium-doped yttrium aluminum garnet laser (Er: YAG) laser, and EndoVac system. The rest 4 teeth were used as control groups (2 positive and 2 negative control groups). After coronal access, all teeth were instrumented by Protaper Next rotary files (Dentsply-Maillefer, Ballaigues, Switzerland) up to size X3, followed an irrigation protocol and filled with pure calcium hydroxide powder mixed with saline. Teeth were stored in an incubator for 7 days, and then, calcium hydroxide was removed using 3 techniques: Manually (Group 1), by ultrasonic irrigation (Group 2), by laser Er: YAG and x-pulse tip (Group 3), and by EndoVac system (Group 4). The teeth of control groups were instrumented as the experimental groups; no removal technique was applied in positive group, whereas in negative one, the root canals were left empty. Teeth were sectioned longitudinally and observed under SEM Results were statistically analyzed with the Kruskal–Wallis Test and Mann–Whitney Test.

Results:

The results showed a significant difference between laser and the other three groups in coronal and middle root third, but no statistic difference in apical third.

Conclusion:

Laser improved the removal of calcium hydroxide in comparison with conventional techniques.

Effect of rotary instrument associated with different irrigation techniques on removing calcium hydroxide dressing

Calcium hydroxide [Ca(OH)2 ] residues in root canals may compromise sealing of filling and endodontic treatment success. The aim of this study was to compare the efficacy of using rotary instrument associated with EndoActivator, EndoVac, passive ultrasonic irrigation (PUI), and conventional needle irrigation (CNI), in Ca(OH)2 removal from root canal, by means of scanning electron microscopy (SEM) images. Sixty-six human canines were prepared with the Protaper system up to F5 and filled with Ca(OH)2 . After 7 days, Ca(OH)2 was removed with rotary instrument F5 associated with the irrigation techniques used in each group (n = 15): GI (CNI), GII (EndoVac), GIII (EndoActivator) and GIV (PUI). In all groups 15 mL of 2.5% NaOCl and 3 mL of 17% EDTA were used for Ca(OH)2 removal. The Ca(OH)2 residues was evaluated by SEM in the middle and apical third using a system of scores. The results were analyzed by the Kruskal-Wallis and Dunn tests (α = 0.05). None of the techniques completely removed the Ca(OH)2 from root canals. There was no difference between EndoActivator, EndoVac and PUI (P > 0.05), but the three techniques removed more Ca(OH)2 than the CNI (P < 0,05), in the middle and apical thirds of the root canal. It was concluded that the rotary instrument combined with EndoActivator, EndoVac, and PUI was shown to be more efficient than the rotary instrument combined with the CNI in removing Ca(OH)2 from the root canal.