Effect of Low-level Laser Therapy With Different Locations of Irradiation on Postoperative Endodontic Pain in Patients With Symptomatic Irreversible Pulpitis: A Double-Blind Randomized Controlled Trial

Abstract

Introduction: This double-blind, placebo-controlled, clinical trial aimed to investigate the analgesic efficacy of low-level laser therapy (LLLT) with two different locations, and their comparison, in postoperative endodontic pain (PEP) levels in molars diagnosed with symptomatic irreversible pulpitis. Methods: Seventy-five patients with a molar tooth, diagnosed with symptomatic irreversible pulpitis, were divided into three groups of placebo, buccal only irradiation (BI), and buccal and lingual irradiation (BLI), with 25 cases being in each group. The participants received similar singlevisit nonsurgical endodontic treatments. Then, a sham laser was used in the control group instead of LLLT. Individuals in BI and BLI groups received 80-second irradiation on the buccal surface and 80-second irradiation on each of the buccal and lingual surfaces respectively. A laser with an 808 nm wavelength, power of 100 mW, a fiber diameter of 600 μm, and a dose of 70 J/cm2 was used. PEP was assessed using a 0-100 mm VAS 4, 8, 24, and 48 hours after the treatment. Results: BLI showed a significantly higher reduction of PEP compared to placebo in all time intervals of this study. BLI was significantly more effective than BI 8 hours after the treatment. However, intragroup differences between BLI and BI groups at other time intervals and between BI and placebo groups in all time intervals were not significant. The number of taken analgesics in the BLI group was significantly lower than the placebo group and was on a statistical borderline compared to the BI group. Conclusion: LLLT with BLI was an effective measure as a supplement to oral analgesics in the reduction of PEP compared to the placebo.

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

“…Many clinical trials have proved the effectiveness of LLLT on endodontic pain after initial root canal treatment (Doğanay Yıldız & Arslan, 2018; Lopes et al, 2019; Nabi et al, 2018; Naseri et al, 2020). The pain control mechanisms of laser irradiation are attributed to the reduction in inflammatory prostaglandin, interleukin 1β and TNF‐alpha (Arslan et al, 2017); reduction of inflammatory processes; inhibition of firing nociceptors; increasing lymphatic drainage and increasing histamine release (Doğanay Yıldız & Arslan, 2018); increased production of inhibitory prostaglandins such as PGI2 (Arslan et al, 2017; Metin et al, 2018); inhibiting the synthesis of pro‐inflammatory factors and neurotransmitters related to pain sensation (Arslan et al, 2017); increased level of immunoglobulins and lymphokines and their effects on the immune system (Metin et al, 2018); increased production of beta‐endorphin and encephalin (Arslan et al, 2017) and elevated level of adrenocorticotropic hormone (ACTH) (Hagiwara et al, 2007; Laakso et al, ), which are all effective in analgesia.…”

“…Following pioneer studies that have focused on LLLT after endodontic surgery using 809‐nm laser (Kreisler et al, 2004), RCT on teeth with vital pulps and symptomatic irreversible pulpitis with 808‐nm diode (Naseri et al, 2020), RCT of teeth with necrotic pulps and symptomatic apical periodontitis using 970‐nm and 808‐nm diode lasers (Doğanay Yıldız & Arslan, 2018; Lopes et al, 2019) and after single‐visit RCT in combination with ibuprofen using 1064‐nm diode (Nabi et al, 2018), the present clinical trial evaluated the effect of LLLT with 980‐nm diode on pain after root canal retreatment. In this study, the condition of the teeth was standardized to minimize the effect of confounders.…”

“…Post‐treatment pain following root canal treatment or retreatment may negatively affect the patient's trust and compliance (Nabi et al, 2018; Naseri et al, 2020). Post‐treatment complications following root canal treatment include acute pain sometimes accompanied by swelling.…”

“…In Endodontics, the positive effect of LLLT in reducing postoperative pain has been reported after endodontic surgery (Kreisler et al, 2004), after root canal treatment (RCT) in teeth with symptomatic apical periodontitis (Doğanay Yıldız & Arslan, 2018; Lopes et al, 2019), after single‐visit RCT in combination with ibuprofen (Nabi et al, 2018) and after root canal treatment of teeth with symptomatic irreversible pulpitis (Naseri et al, 2020). In the field of root canal retreatment, only two studies have evaluated the effects of LLLT on post‐treatment pain (Arslan et al, 2017; Asnaashari et al, 2017).…”

Effect of laser assisted local anesthesia in single-visit root canal treatment for mandibular molar teeth with acute irreversible pulpitis

“…No direct comparison of the present results with other studies could be made as a literature search failed to identify any similar attempts to assess lasers for irreversible pulpitis. Earlier studies on laser application for the management of irreversible pulpitis to control intra- and post-operative pain have been done using laser irradiation on the external tooth surface, either before or after root canal treatment, but not directly on the pulp during the treatment procedure (7, 14, 15).…”