Effect of low‐level laser therapy on postoperative pain after single‐visit root canal retreatment of mandibular molars: A randomized controlled clinical trial

Abstract

Aim To compare the effect of low‐level laser therapy (LLLT) on postoperative pain after single‐visit root canal retreatment on mandibular molars. Methodology This randomized controlled clinical trial included 36 patients referred to the Department of Endodontics, Islamic Azad University, Tehran, Iran. Healthy patients who required root canal retreatment on symptomatic first or second mandibular molars, with a PAI index score of 2 or 3, preoperative tooth and percussion pain of <56 mm on a 170‐mm visual analogue scale (VAS) were included. After local anaesthesia using inferior alveolar nerve block followed by rubber dam isolation and access cavity preparation, the D RaCe retreatment system was used to remove the existing root filling material, and after canal negotiation and gaining patency, working length was determined with an apex locator. Further canal enlargement was carried out with size 35, 0.04 taper, and size 40, 0.04 taper RaCe rotary instruments and then canals were filled using laterally compacted gutta–percha points and AH Plus sealer. The patients were randomly assigned to treatment groups: In the LLLT group, a 980‐nm diode laser set at 6.89 W/cm2 energy density, 0.5 W power, and a tip diameter of 10 mm were activated from the buccal side on the mesial and distal root apices for 15 s. In the sham group, the laser handpiece was placed inside the patient's mouth at the same location, but the laser was not activated. Then patients were instructed to record their postoperative pain levels at 4, 8, 12 and 24 h and 2, 3 and 7 days after treatment on separate VAS scales. For data analysis, the independent sample t and the Mann–Whitney U tests were used. Nominal variables were analysed by using the chi‐square test. Results In the LLLT group, the most intense pain was reported 24 and 48 h post‐treatment [mean (SD) = 0.22 (0.54) for both], whereas in the sham group, the most intense pain level was observed 4 h post‐treatment [mean (SD) = 0.78 (0.80)]. At the 4‐h interval, pain intensity was significantly lower in the LLLT group (p = .016). Conclusions Low‐level laser therapy reduced postoperative pain after single‐visit root canal retreatment of mandibular molars only four hours following the procedure.

Effect of Low-level Laser on Proliferation, Angiogenic and Dentinogenic Differentiation of Human Dental Pulp Stem Cells

“…Also increased production of DSP and VEGF was observed compared to control group. LLTI exerts regenerative effects (22). However, many parameters in uence the effect of LLLI, one of which is the tissue penetration depth (57).…”

“…low-intensity laser radiation (LLLI) (12). LLLI is a non-invasive procedure that induces athermic, nondestructive photobiological processes (22). LLLI is effective in pain reduction, wound healing, bone repair and remodeling, nerve repair and angiogenesis (12,22).…”

Regenerative endodontic therapy in mature teeth with necrotic pulp and apical periodontitis using two disinfection protocols

“…In the present study, we used bio-stimulation to enhance the regeneration. Using bio-stimulation technique as low-level laser treatment stimulates regeneration processes without significantly increasing body temperature because it enhances cellular metabolism, protein expression, cell migration, proliferation, and differentiation [ 20 ].…”

“…In both groups I and II, 980-nm diode laser (Pioon, China) was used for laser irradiation for 15 s at 0.5 W power and a tip diameter of 10 mm. With the tip of the laser handpiece held at a distance of about 10 mm from the mucosa, the soft tissues covering the mesial and distal apices of the tooth were exposed to laser radiation from the buccal and lingual sides [ 20 ].…”

Two-year Follow-up of Avulsed Teeth Submittted to Laser Therapies: A Case Report

“…Relative to complications affecting the pulp, pulp necrosis was found after 4 weeks of follow-up, and internal root resorption, after one year [4]. Both antimicrobial Photodynamic Therapy (aPDT) and Photobiomodulation Therapy (PBMT) using low power laser can be used during the postoperative phase to reduce the local bacterial load and accelerate the healing process (by affecting cellular metabolic processes), respectively [5,6] to prevent these occurrences. Photobiomodulation Therapy (PBMT) is based on applying light emitting diodes from LASERS or LEDS to promote pain control, modulation of inflammation, and tissue repair.…”