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Statement of the Problem: Healing of the inferior alveolar nerve injury during dental procedures is one of the biggest concerns of dentists. There are still debates on different treatment modalities. Purpose: This study aimed to compare the effect of 940nm and 810nm diode lasers on the repair of the inferior alveolar sensory nerve. Materials and Method: In this single-blinded randomized clinical trial, 39 patients with inferior alveolar nerve injury were divided into three groups: 1. 810nm laser irradiated, 2. 940nm laser irradiated, and 3. No laser irradiation (control group). All patients were treated in 12 sessions (3 days per week) and evaluated using a complete clinical neurosensory test (CNT), including brushstroke, 2-point discrimination, pinprick nociception, and thermal discrimination before and after treatment. Results: The mean dysesthesia of the patient treated with 810nm diode laser was significantly lower than the control group in all sessions (the 1st (p= 0.003), 3rd (p=0.008), 7th (p= 0.006), and 12th sessions (p= 0.005)). The 810nm laser resulted in more satisfaction in patients than the control group in almost all sessions (1st (p< 0.001), 7th (p= 0.028), and 12th (p= 0.006)). More patient satisfaction was seen in the 1st and 3rd sessions in the 810nm laser than in the 980nm laser (p< 0.001 and p= 0.003, respectively). Conclusion: 810nm diode laser can be better than 940nm in repairing inferior alveolar sensory nerve damage. [ABSTRACT FROM AUTHOR]

Low-level laser therapy (LLLT) is a noninvasive technique used in different medical fields. It has been applied in different medical areas such as wound healing, traumatic brain injuries, neurological disorders, cognitive disorders, Alzheimer's disease, pain, and arthritis, with different results. We studied the effectiveness of LLLT on cognitive impairment in patients with chronic schizophrenia. A randomized controlled double-blind clinical trial was performed in a men's chronic treatment center, in Razi Psychiatric Hospital, in Tehran, Iran. We screened the cognitive impairment by Mini-Mental State Examination (MMSE). Positive And Negative Syndrome Scale (PANSS) was also used to assess the patients' positive and negative symptoms. Seventeen consenting patients were randomly allocated to the treatment arm, and 15 to the sham treatment control arm. The mean age of the control and treated patients was 49.47 ± 6.99 and 50.24 ± 7.69, respectively. No significant difference in PANSS and MMSE test scores was detected in both groups after the 6th session and after 2 months of follow-up after laser therapy. The positive and negative scales and agitation and excitement levels did not change significantly in either group. Nevertheless, the depression/anxiety subscale in the PANSS test showed a significant reduction after 6 sessions but did not persist after 2 months. No improvement in cognitive impairment or the positive and negative symptoms was detected after LLLT in patients with chronic schizophrenia. Trial registration: IRCT 20210520051349N1., (© 2022. The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature.)

Periorbital hyperpigmentation is a problem with complex multifactorial etiology, with early knowledge expanding. The purpose of the present study was to review studies on the efficacy of laser on periorbital hyperpigmentation. A systematic review of the data banks of scientific and research articles including PubMed, Web of Knowledge, Google Scholar, SCOPUS, and Iranian databases including SID and Magiran is performed. The following keywords were used to evaluate existing articles: Periorbital Hyperpigmentation, Periorbital Darkening, Dark Eye Circle, Eye Dark Circle, Infraorbital Hyperpigmentation, Infraorbital Dark Circle, and Laser (1990-2018). Finally, 10 clinical trial articles were included. A total of 2.76% of patients responded poor, 11.4% responded fair to different types of lasers, 45.3% responded good, and 35.9% excellent responded to have been cured. As a long-term effect, less than 1% of patients received a poor score after their laser treatment. Twenty-five percent of the patients showed a fair result. In total, 26.27% of patients achieved good and 43.35% of patients received excellent response from laser treatment on periorbital hyperpigmentation after 4-6 months of laser therapy. A large percentage of patients (76.4%) were satisfied with the effect of lasers on the reduction of moderate to high periorbital hyperpigmentation rates in the studies. Laser therapy is an effective and satisfactory therapeutic choice for treatment of periorbital hyperpigmentation. Also, it is safe overall with favorable sustainable results, although the follow-up periods usually last about several months., (© 2021. The Author(s), under exclusive licence to Springer-Verlag London Ltd. part of Springer Nature.)

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/cm 2 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., (© 2021 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

Background: The growth and proliferation of gingival fibroblasts are important in the process of oral wound healing, and photobiomodulation (PBM) might be able to modify this process., Objectives: The aim of the current study was to evaluate the biomodulatory effect of a single session of laser PBM by means of 810 nm and 940 nm diode lasers alone and their combined application with different fluencies on human gingival fibroblasts (HGFs)., Material and Methods: Cells were provided by the Pasteur Institute, the National Cell Bank of Iran (NCBI) (C-165). Laser irradiation was carried out using 810 nm, 940 nm and 810 nm + 940 nm in the continuous wave (CW) mode, 100 mW, and energy densities of 0.5, 1.5 and 2.5 J/cm2. Cell viability was evaluated at 24 h with the MTT assay. Trypan blue staining was used to evaluate proliferation 24, 48 and 72 h after laser therapy. Propidium iodine was used to stain DNA and the cell nucleus., Results: Laser irradiation (810 nm, 0.5 J/cm2) increased the viability of gingival fibroblasts, while this dose had an inhibitory effect with 940 nm. No positive effect on cell viability was found with other settings at 24 h. The viability results were not statistically different from those of the control in the dual wavelength group. At all single-laser irradiation doses, the cell proliferation results were lower as compared to the control at 48 and 72 h. The dual wavelength group results were significantly better than those of the control for the 1.5 J/cm2 and 2.5 J/cm2 energy densities (p < 0.001). Propidium iodine staining showed no negative effect of laser irradiation on the cell nucleus in any of the groups., Conclusions: Although a single irradiation dose of 810 nm, 0.5 J/cm2, resulted in a positive effect on cell viability at 24 h, no statistically significant stimulatory effect on viability and proliferation was observed for the other single wavelength group. When a combination of the 2 wavelengths was used, better results were observed as compared to the control, which needs to be further investigated in future studies.

Background: Enhanced sperm motility is necessary for the successful journey of sperm inside the female genital tract, successful fertilization, and the increased chance of pregnancy. Objective: We investigated the impact of red and near-infrared (NIR) ranges of photobiomodulation (PBM) alone and together on fresh human sperm to validate an optimized PBM protocol that would maximize sperm motility and viability in vitro . Methods: We randomly divided 30 normal human semen samples into 3 different PBM protocols (red, NIR, and red+NIR lasers). Each sample was divided into four subparts, one control group sample and three experimental group samples. Each experimental group received one of the PBM protocols (red, NIR, or red+NIR). Each protocol was adjusted to three energy densities (0.6, 1.2, and 2.4 J/cm 2 ). After exposure to the selected protocol, we determined the percentage of either viable or progressive sperm motility (PSM) and measured the DNA Fragmentation Index (DFI). Results: The NIR and red+NIR lasers at 2.4 J/cm 2 energy density significantly increased PSM after 60 min compared with the control groups [least significant difference (LSD) test, p  = 0.023 and p  = 0.04, respectively]. Samples treated with the red laser at 0.6 J/cm 2 had significantly decreased viability compared with the control group (LSD test, p  = 0.003). Samples treated with the red+NIR lasers had significantly decreased viability at 0.6 J/cm 2 ( p  = 0.003), 1.2 J/cm 2 ( p  = 0.001), and 2.4 J/cm 2 ( p  = 0.04) energy densities when compared with the control groups. The NIR laser resulted in no significant difference in sperm viability between the control and experimental groups. At 120 min after exposure, treatment with the red+NIR and red lasers at 2.4 J/cm 2 density significantly increased DFI compared to the control groups (LSD test, p  = 0.000, p  = 0.007). Conclusions: In this study, sperm motility, viability, and DFI data confirmed the superiority of the NIR laser at 0.6 J/cm 2 energy density compared with the red and red+NIR PBM protocols.

Objectives: A randomized, double-blind, clinical trial study was conducted with the aim of determining the efficacy of adding laser (830 nm) to ultrasound (US) and exercise for the management of shoulder tendonitis., Methods: 42 subjects (n=21, in adding laser group and n=21, in US and exercise group) received a course of 10 sessions treatment over one month in the shoulder region. Outcome measures such as Visual Analogue Scale (VAS), Tenderness Severity Scale (TSS), Constant Murley Score (CMS) and Manual Muscle Testing (MMT) were performed before treatment and at the end of 4 weeks treatment. In addition, follow up were performed 2 months after the end of treatment based on the degree of pain improvement., Results: VAS, TSS and CMS improved significantly (P=0.001) in both groups, however the muscle strengths only improved significantly in adding laser group (P< 0.01)., Conclusion: It seems that both protocols of physical therapy interventions were effective in relieving the signs and symptoms of shoulder tendonitis. Furthermore, adding low level laser therapy (LLLT) to the US and exercise was more efficient in improving the muscle strength in patients with shoulder tendonitis over a period of three months. However, it should be emphasized that, the current results might be due to the effects of laser and exercise instead of laser, us and exercise (as we had no independent group for US).