Fahimeh Anbari

Radiation-induced hyposalivation is a common and debilitating side effect of head and neck radiotherapy, significantly impairing patients’ quality of

Introduction: Chondrocytes are the major cell in hyaline cartilage playing a crucial role in maintaining the mechanical resilience of the tissue. We assessed the effect of an 808nm diode laser on the proliferation of human chondrocytes. Methods: This study was conducted on human chondrocytes in vitro. The cells were divided into 5 cases and one control group. The cells were irradiated by low-level laser 808 nm, with energy levels of 1, 2, 3 J/cm² (0.2 W, for 5, 10, and 15 seconds), 4 J/cm² (0.3 W,13 s), and 5 J/cm² (0.4 W,12 s). The culture was incubated for 24 hours. The MTT assay was performed to determine the cell viability. After 72 hours of incubation, the procedure was reperformed to assess the effect of incubation duration. The cell viability in terms of incubation duration and irradiation parameters were investigated by a two-way ANOVA test. Pairwise comparisons were performed using the Bonferroni test. Results: In the 72-hour incubation group, cell viability in the group that received 5 J/cm² energy was significantly lower than that in the groups receiving 1 J/cm², 2 J/cm² and 4 J/cm² irradiation. The variables of time (P=0.001) and energy level (P=0.024) had significant effects on the cell viability of the samples. In the 24-hour incubation groups, no significant difference in cell viability was observed. Conclusion: The diode 808 nm Low-level laser irradiation (LLLI) at doses of 5 J/cm² and less did not show a significant increase in the proliferation of chondrocytes (regardless of incubation time). However, the best survival rate of chondrocytes was observed in the group of 4 J/cm² with 72-hour incubation.

Introduction: Nowadays, esthetic appearance plays an important role in the field of dentistry. Discolorations and pigmentations of the gingiva reduce the appearance of a healthy-looking smile. On this occasion, the use of lasers shows a promising approach for a fast and non-aggressive treatment in this field. Different laser wavelengths are being used for gingival depigmentation this clinical study aimed to investigate the effect of the novel laser wavelength (445 nm) in this field and compare it with an 810 nm diode laser. Methods: Two diode laser wavelengths (445 nm and 810 nm) were used for depigmentation. The laser output power chosen was 1 W. An optical fiber with a diameter of 400 µm was used. 21 patients with pigmented gingiva were selected. Depigmentation was carried out in a split-mouth design for a direct comparison of the clinical effect. Outcomes were documented by photograph after one month and six months of follow-up. Results: For each wavelength, 21 volunteers evaluated 21 clinical cases of depigmentation, which means that 441 comparisons were carried out in total regarding the color change from brownish to pinkish. A 100% clarification was achieved for 445 nm. In the 810 nm group, the color change in 44 of 441 cases (10%) could not be clearly identified. No statistically significant difference in pain experience was reported for both laser treatments. Conclusion: The clinical evaluation showed that within the limitations of this study, most of the clinical outcome parameters were highly acceptable by the patients due to mild pain and discomfort for both laser systems.

Introduction: Using lasers in melanin depigmentation is one of the main fields of interest for dental practitioners and patients. However, it is important to know what would happen inside the tissue and how the cells would interact inside the tissue with a laser. Methods: In this study, we used both wavelengths of 445 nm and 808 nm on sheep gingiva to find out the effects and side effects of these diode lasers while using them for gingival depigmentation. Results: After microscopic evaluation, we concluded that 808 nm and 445 nm lasers with a power of 1 W are safe enough to use in the depigmentation of gingiva, and both lasers are highly effective in melanin pigments which are located in basal membrane. Conclusion: The 445 nm blue laser produced a less thermal effect, which means it is safer to be used in gingival hyperpigmentation than a diode laser.

Taheri JB, et al. J Dent Anesth Pain Med. 2022 Aug;22(4):289-294. https://doi.org/10.17245/jdapm.2022.22.4.289

Purpose: Oral lichen planus (OLP) is a chronic inflammatory disease of the oral mucosa, which has potential for malignant transformation. MicroRNAs play an important role in immunopathogenesis of OLP, and may be used for prediction of its malignant transformation.This study aimed to assess the salivary level of microRNA-146a and microRNA-155 biomarkers in patients with OLP and oral squamous cell carcinoma (OSCC). Methods: In this case-control study, unstimulated saliva samples were collected from 60 patients, including 15 patients with dysplastic OLP, 15 OLP patients without dysplasia, 15 patients with OSCC, and 15 healthy controls according to the Navazesh technique. After RNA extraction, the expression of microRNA-146a and microRNA-155 was quantified by real-time quantitative polymerase chain reaction (RT-qPCR). The data were analyzed by the Kruskal-Wallis and Dunn-Bonferroni tests. Results: The difference in expression of microRNA-146a and microRNA-155 among the four groups was significant (P0.05). Conclusion: MicroRNA-146a and microRNA-155 may serve as early biomarkers in OLP. Also, considering the altered expression of microRNAs in dysplastic OLP and OSCC, their altered expression may serve as an alarming sign of malignancy. However, further investigations are still required.

Introduction: It has been demonstrated that laser technology can enhance topical drug absorption. This study aimed to determine the effects of Er,Cr:YSGG laser radiation before the application of topical corticosteroids in the healing of oral lichen planus. Methods: In this double-blind split-mouth clinical trial, 32 lesions were chosen from eight patients affected by oral lichen planus (OLP). The oral lesions were randomly categorized into two groups. The first group had topical treatment with triamcinolone NN ointment and the second group had laser radiation (Er,Cr:YSGG) for eight weeks before starting the ointment. For each lesion, the irritating level based on the VAS score, the lesion level based on the Thongprasom scale score, and the healing time were measured, and the collected data were analyzed by the Friedman test and the Wilcoxon’s statistical test. Results: The mean healing time based on the verbal analog scale (VAS) score was not significantly different between the two treatment groups (P>0.05). The mean healing time based on Thongprasom scale scores did not show any significant difference between the two treatment groups (P>0.05). Conclusion: The application of the Er,Cr:YSGG laser before treatment with triamcinolone NN ointment did not show any advantage for the average healing time compared to a medicine regimen with only triamcinolone NN ointment.

Khalighi HR, et al. J Dent Anesth Pain Med. 2022 Feb;22(1):19-27. https://doi.org/10.17245/jdapm.2022.22.1.19

Introduction: The golden standard of the treatment of radicular cysts is mainly root canal therapy or surgical excision with apicectomy. The root canals are usually disinfected by the mechanical and chemical actions of instruments and chemical irrigating solutions respectively. To improve the efficacy of the root canal disinfection process, many techniques have been used and many researchers are still trying to reach the quickest and most convenient way to achieve this goal. Diode lasers have shown antibacterial activity on dentinal tubules, and they can penetrate more than 1000 μm into the dentin. Case Presentation: Our patient was a 25-year-old female with an infraorbital abscess caused by a non-vital maxillary canine with periapical radiolucency. After completing the conventional treatment, the optical fiber was inserted into the canal according to the working length previously measured. An 810 nm diode laser at the output power of 4 W was used to irradiate the root canals, with a 300 μm fiber. The patient was free of pain within a few days. The lesion was resolved in radiographic follow-ups, 3 and 6 months after the root canal treatment. Conclusion: A combination of conventional root canal therapy and an 810 nm diode laser is an effective treatment for non-vital teeth with periapical lesions.