Journal of Lasers in Medical Sciences

Letter to editor regarding to article "The Effects of Photobiomodulation Therapy on Post-Surgical Pain", Kamran Ezzati, Reza Fekrazad, Zeinab Raoufi. J Lasers Med Sci 2019 Spring;10(2):79-85

Introduction: High-intensity laser therapy (HILT) has been used more recently in the therapeutic protocols of pain managements. Adding therapeutic interventions to laser therapy is usual in clinical practice. This study aimed to evaluate the efficacy of HILT and beneficial effects of adding co-interventions to HILT in musculoskeletal pain management.

Methods: The following databases were searched up to August 2018: Medline, PubMed, EMBASE, Cochrane, Google Scholar, Springer and ISI. The keywords of pain, HILT, high power laser therapy, laser therapy, photobiomodulation, physical therapy and rehabilitation were searched. The quality of the articles was assessed using the PEDro scale. The primary measure was pain severity expected to be reported in all studies. Effect size was calculated as standardized mean differences divided by the standard deviation of either the treatment or other group.

Results: Initially 52 potential studies were found. Eighteen of these studies were excluded based on title and abstract. The full text of 34 remaining articles was screened and 15 of the studies were excluded. All included studies had high quality (PEDro ≥7). Approximately, 94% of included articles (n=18) revealed positive effects of HILT on pain. The effect sizes for HILT and placebo/comparator groups were 0.9-9.11 and 0.21-11.22 respectively. Also, the differences of effect size between two groups were between 0.03 to 5.85.

Conclusion: It is early to determine that HILT may be an effective non-invasive agent in the management of musculoskeletal pain, as few studies have shown its clinical efficacy. Adding related co-interventions to HILT may enhance the beneficial effects of laser therapy. The variability of the study methods and outcomes suggests that further long-term follow-up, randomized controlled clinical trials with appropriate methodological design are needed regarding the effectiveness of HILT on pain.

Lasers have wide applications in the treatment and diagnosis of diseases and various medical fields. Laser therapy like the other methods has advantages and disadvantages. Some risks such as bleeding, pain, and infection are created after laser therapy. Explanation and evaluation of laser effects on cell function, tissue, and the body are the aims of this study. We reviewed papers available from 1986 to 2019 about the effects of lasers on cells and tissue. An online search of PubMed, Science Direct and Google scholar using such keywords as “laser”, “cell”, “tissue”, “body” and “side effects” was performed. The laser photons are absorbed by chromophores, resulting in the target heating and localized damage. Laser irradiation alters cellular metabolism and cellular functions. These alterations may be accompanied by undesired side effects which can be monitored via metabolites level change in the body. Based on this finding, laser therapy may be associated with several side effects and complications; therefore, before treatment, the determination of laser types and their properties is necessary to avoid creating side effects. The advantages and disadvantages of the treatment type should be considered in order to choose the best treatment with the least side effects. The patients’ awareness of possible side effects before treatment and also an effective follow-up and management of patients after action are two important points in laser therapy. Training curriculum definition should be determined for laser applicant qualifications in different medical fields.

Introduction: The treatment of nail psoriasis is often difficult and unsatisfactory due to therapy resistance. This study aimed to compare the efficacy of clobetasol 0.05% ointment and photodynamic therapy (PDT) using aminolevulinic acid (ALA) and red light in the treatment of severe nail psoriasis.

Methods: This open-trial study included 69 nails of 8 patients with severe nail psoriasis. Thirty-four nails were treated with clobetasol 0.05% ointment and 35 nails were treated with ALA-PDT. ALA-PDT treatment was performed every 3 weeks for 5 cycles; the nails were treated with clobetasol under occlusion every day during the study. All the patients were followed up after 24 weeks. The severity of nail involvement was measured by the Nail Psoriasis Severity Index (NAPSI) scores at the baseline and during the treatment.

Results: There were no significant differences in the NAPSI scores between the treatment groups in the baseline and weeks 3, 6 and 9 (all P > 0.05), although significant differences were found in weeks 12, 15 and 24 (follow-up) (P < 0.001). A significant time-effect improvement was found in all the nail-matrix, nail-bed and total NAPSI scores in both treatment groups (all P < 0.001). The patients did not report intense pain and discomfort during irradiation.

Conclusion: Clobetasol 0.05% ointment seems to be effective in treating nail psoriasis after a treatment period of 15 weeks. However, the efficacy of ALA-PDT at a 24-week follow-up was greater than that of clobetasol.

Introduction: Smoking as one of the causes of various diseases has encouraged worldwide studies on its adverse pharmacological effects on different organs. Nicotine may influence the smooth muscles of the colon and subsequently the gut motility, which leads to a change in the moving rate of digested material through the gastrointestinal tract.

Methods: Among various techniques, optical detection methods benefit from non-contact and high-sensitivity for studying the early effect of nicotine on the cells. Thus, we used an optically ellipsometric method to get the fast and sensitive nicotine effect on the colon cell. Two-dimensional plasmonic platforms by gold deposition onto the polydimethylsiloxane polymer (PDMS) patterned substrate were used as the guest medium of the cell and the sample was excited by all of the visible region wavelengths at different exposure time and maintenance time.

Results: Our results showed that the phase difference between each polarization increased by augmenting the exposure time of smoke over the cell at a fixed maintenance time and there was a general red-shift by increasing the maintenance time at a fixed exposure time.

Conclusion: Using different exposure time to cigarette smoke, we optically showed that the cigarette containing the addicting chemical of nicotine had a direct effect on the cultured colon cells on our 2D biocompatible plasmonic chip. It demonstrated considerable changes in the amplitude and phase of the interacted light by injecting nicotine into the system with the aid of the label-free and non-invasive plasmonic technique.

Introduction: This study assessed the effect of polarized low-level laser therapy (PLLLT) in the treatment of myofascial trigger points (MTrPs) in the trapezius muscles. Its effectiveness in pain reduction was compared to low-level laser therapy (LLLT).

Methods: 64 patients with MTrPs were randomly divided into two groups, namely, PLLLT and LLLT. Each patient received treatment for a period of 2 weeks, 5 sessions a week. The intensity of laser irradiation to the skin surface was 6 J/cm². The system exit power was 160 mw at 755 nm wavelength. The Visual Analog Scale (VAS) for the 1^st, 5^th and 10^th sessions was analyzed through two-way repeated measures ANOVA.

Results: Increasing the number of treatment sessions was effective in reducing pain intensity (P> 0.05). The effect of LLLT in pain reduction was significantly greater than that of PLLLT (P>0.05). Referred pain (RP), limitation of neck movement (LNM), presence of muscular taut band (PMTB) and sensitivity of muscular taut band (SMTB) were reduced significantly by the end of the 10^th session, compared with participants’ condition at the beginning of the 1^st session in both groups.

Conclusion: PLLLT and LLLT can effectively treat MTrPs of the trapezius muscles, especially to reduce RP, LNM, PMTB and SMTB. However, the effect in the LLLT group was significantly greater than in the PLLLT group. In accordance with the observed results, LLLT is recommended as an effective method for treating MTrPs.

Introduction: Diabetes mellitus (DM) is a common disease with a highly significant burden among the Saudi population. This study aimed to investigate the effects of adding either magnetic or laser therapy to medications in patients with diabetic peripheral neuropathy (DPN).

Methods: Seventy-one medically controlled diabetic patients were randomly assigned to 1) Magnetic group: 26 patients were exposed to magnetic therapy for 20 minutes/session, 2 sessions/week, for 3 months 2) Laser group: 25 patients were exposed to laser therapy with intensity 5.7 J/cm2 for 30 minutes/session, 2 times/week, for 3 months. 3) Drug group: 20 patients received only the regular medications for diabetic control and pain analgesia. Pain and neuropathy were assessed by the visual analog scale (VAS) and the Toronto Clinical Neuropath Scoring System (TRCNSS). Conduction velocities and amplitudes of peroneal and sural nerves were measured by electromyography.

Results: The results showed significant increases in conduction velocities and amplitudes in both magnetic and laser groups in parallel with significant reductions in TRCNSS. Non-significant changes were obtained only after using only medications (P > 0.05). The mean values of VAS reduced significantly in the three groups. The least significant differences showed significant changes among the three groups, whereas non-significant differences were obtained between both magnetic and laser groups.

Conclusion: There were non-significant differences between both magnetic and laser therapy groups. Addition of either magnetic or laser therapy to medications could bring extra positive benefits to patients with DPN. Both magnetic and laser therapy can be applied with medications for the treatment of patients with DPN.

Introduction: Recently, laser treatment for hair loss has become very popular. Laser-assisted drug delivery (LAD) is an evolving technology with potentially broad clinical applications. This work aims at inspecting the effect of the fractional carbon dioxide laser (CO2) on improving the delivery of minoxidil in patients with androgenetic alopecia and detecting the role of the fractional CO2 laser in its treatment.

Methods: We enrolled 45 Egyptians with male androgenetic alopecia (MAGA); clinical grading was assessed based on Norwood-Hamilton classification. The patients were divided into 3 groups: the first group (combined group) received the fractional CO2 laser session followed by topical application of minoxidil and also in between sessions; the second group received fractional CO2 laser sessions only and 6 sessions with 2-week intervals were performed; the third group applied topical minoxidil only for 3 months. Global photographs and dermoscopic assessments were performed before treatment and 3 months after the treatment.

Results: Several dermoscopic findings were detected, including peripilar sign, hair diversity, yellow spot, white dots, and arborizing red lines. The number of double hair units significantly increased after the treatment in the combined group. The mean number of hair after the treatment in the 3 groups significantly increased, mostly in the combined group. The hair thickness (thin & thick) significantly increased after the treatment in the combined group and the fractional group; however, in the minoxidil group, only thin hair thickness increased. In all the 3 groups, there was a significant improvement in hair count and thickness.

Conclusion: The ablative fractional CO2 laser alone or combined with minoxidil may serve as an additional treatment for MAGA.

Introduction:Myofascial pain dysfunction syndrome (MPDS) is a common temporomandibular joint disorder. Due to its multifactorial etiology, treatment usually involves more than one modality to obtain complementary results. The purpose of this study was to compare the combined effect of low level laser, hard occlusal appliance and conventional pharmacotherapy versus pharmacotherapy only in the management of patients with MPDS.

Methods: In this randomized clinical trial, 15 MPDS patients were diagnosed and randomly assigned to 3 groups (n=5). Subjects in Group 1 were treated with pharmacotherapy (PT), Group 2 received active laser (940 nm Gallium Arsenide) every other day for a total of 10 sessions, plus pharmacotherapy (PTL) and Group 3 were given hard occlusal splint 12 h/day for 4 weeks plus pharmacotherapy (PTO). The intensity of pain was measured using visual analog scale (VAS) prior to treatment, 2 and 4 weeks after treatment onset and 2 weeks later. Maximum painless mouth opening and pain intensity at muscle palpation was also recorded. Comparisons were made between groups in 4 treatment sessions via repeated measure analysis of variance (ANOVA) (P < 0.05).

Results: Pain relief, in subjective VAS was observed in both laser and appliance groups in the third and fourth examination sessions, though occlusal appliance significantly showed to provide the best results between the three groups (p<0.05). No statistically significant reduction in pain was noted using pharmacotherapy only. Maximum painless mouth opening and muscle tenderness was not significantly different among the three groups (p>0.05).

Conclusion: Both Laser and occlusal appliance combined with pharmacotherapy proved to be effective for pain reduction. The 3 groups however failed to result in significant improvement in maximum mouth opening or tenderness of the muscles of mastication.

Introduction: This study aimed to investigate the effect of different surface treatments on the bond strength of resin cement to nickel-chrome (Ni-Cr) alloy.

Methods: Forty disk-shaped specimens of Ni-Cr alloy were prepared and divided into 4 groups. In the first group, the specimens’ surface was sandblasted with 50 μ Al2O3 particles. In the second group, the specimens were prepared with the Er:YAG laser. In the third group, the specimens were prepared using the Er:YAG laser after sandblasting. In the fourth group, the specimens’ surface was covered with a thin layer of MKZ metal primer after sandblasting. Then the cylinders of composite resin were bonded to the treated metal surfaces using Panavia F2.0 resin cement. All of the samples were subjected to 2000 thermal cycles. The shear bond strength was tested using a universal testing machine at the crosshead speed of 0.5 mm/min. The failure mode was also observed by a stereomicroscope. Data were analyzed using the one-way ANOVA and the Tukey HSD test at a significance level of 0.05.

Results: The shear bond strength from the highest to the lowest were as follows: the Er:YAG laser group, the sandblast and MKZ primer combination group, the sandblast group, and the sandblast and Er:YAG laser combination group. The mean differences of shear bond strength between the Er:YAG laser group and the sandblast group (P = 0.047) and also between the Er:YAG laser group and the sandblast and Er:YAG laser combination group (P = 0.015) were statistically significant.

Conclusion: Among the different surface treatments employed in this study, Er:YAG laser treatment increased the shear bond strength between the metal alloy and the resin cement (Pavnavia F2).

Introduction: White Spot Lesions (WSLs) occurring after orthodontic treatment lead to patient dissatisfaction and aesthetic problems. The role of calcium-phosphate demineralization systems and Er:YAG laser in the treatment of these lesions has been recently taken into account. This study was aimed to investigate the effect of Er:YAG laser and MI-Paste Plus on the treatment of WSLs.  

Methods: A total of 65 premolars extracted due to orthodontic treatment were studied in this research. To create enamel lesions, the teeth were placed in a demineralizing solution. The teeth were then randomly divided into five groups (n=13). First group: control, second group: saliva, third group: MI Paste Plus, fourth group: Er:YAG laser, and fifth group: MI Paste together with Er:YAG laser. The teeth were kept in artificial saliva between treatment processes and was exchanged daily. The teeth were sectioned longitudinally by a disc from the middle of the exposed enamel and each section was mounted in polyester resin. The surface of the samples was serially polished and the microhardness of the teeth was measured at depths 0, 50, 100, and 150 µm.  

Results: The microhardness was significantly higher in fifth group than other groups at all depths (P<0.05). The microhardness of fourth group was significantly higher than that of the three other groups at depth 150 µm (p<0.05). The microhardness of third group was significantly higher than that of the control group at depth 0 µm (p<0.0001).

Conclusions: The combined application of the Er:YAG laser and MI Paste Plus is effective in the treatment of WSLs.

Introduction: Periodontal disease (PD) is an inflammatory condition, which leads to tooth loss, promoting a systemic inflammatory state that can act aggravating the nerve degeneration. As laser therapy may stimulate regeneration, the aim of this study was to evaluate the effect of low-level laser on peripheral nerve regeneration under the systemic inflammatory condition of PD.

Methods: 32 male rats were used, distributed in 4 groups: nerve injury (NI); periodontal disease with nerve injury (PDNI); nerve injury and treatment (NDT); periodontal disease with nerve injury and treatment (PDNIT). On the 7th day of the experiment, the animals had ligatures placed around the lower first molars. On the 22nd day, they underwent peripheral nerve damage, and, on the 25th day, we began the low-level laser treatment, performed for 2 weeks. The functional index of the sciatic (FIS) was evaluated with subsequent euthanasia of all the animals on the experiment 37th day. The sciatic nerve was collected for morphological and oxidative stress analysis and the hemi jaws for radiographic analysis.

Results: Regarding the FIS, there was no difference among groups in the first evaluation (EV) pre-injury, as for theEV2, after injury, all groups presented a decrease in these values, which remained post treatment. For the morphology of the PDNI nerve tissue presented larger diameter fibers, whereas NIT and PDNIT fibers had smaller diameters, with endoneural organization. When it comes to the antioxidant system, there was an increase in protein concentration, higher superoxide activity, and decreased glutathione transferase activity in the treated groups. Catalase and cholinesterase did not differ between groups, and lipoperoxidation was increased in the PD groups. For the mandible radiographic analysis, it was possible to verify the induction of PD.

Conclusion: As for the used parameters, the low-level laser was not effective in increasing the nociceptive threshold, but it contributed to the regeneration of nerve fibers, although the inflammation was still present in the site. However, the treatment was effective in protecting cells against oxidative damage due to increased SOD and increased protein, although the decrease in GST demonstrates the inhibition of this stage of the antioxidant system.

Introduction: After menopause women experience vaginal atrophy related to hormonal changes and estrogen deficiency. The purpose of this paper was to evaluate the effect of the fractional CO2 laser on the quality of life, vaginal atrophy symptoms, and urine incontinency in menopause women.

Methods: This prospective study was conducted among 140 women from 2017 to 2018 in Yas hospital, Tehran University of Medical Sciences. They encountered the fractional microablative CO2 laser system three times at four-week intervals. The short form of the Health Questionnaire (SF-12) and the Female Sexual Functional Index (FSFI) questionnaire were utilized to assess the participants’ quality of life. Also, the standard measuring tools including the vaginal health index (VHI) and International Consultation on Incontinence Questionnaire (ICIQ) Form were used to evaluate the vaginal atrophy symptoms.

Results: The quality of life improved significantly in somatic, social function, and mental health. In the sexual context, arousal and satisfaction status improved significantly. Also, the frequency of urinary incontinence, enuresis, urgency, and the leak improved significantly (P < 0.05). Among the scale variables for urinary function, it was seen that the urgency impact had no improvement. All vaginal indices improved (P < 0.05).

Conclusion: The fractional CO2 laser can be effective in treating vaginal atrophy and urinary symptoms. Besides, it improved the quality of life and the sexual function of

Introduction: Melasma is one of the most common skin pigmentation disorders, which mostly affects the facial skin and has a considerable psychological impact on the patients. Melasma management has been one of the controversial issues in dermatology. We aimed to compare the combined treatment of the Er: YAG (erbium: yttrium–aluminum–garnet) laser plus hydroquinone (HQ) 4% with HQ 4% alone in the treatment of melasma.

Methods: Twenty-nine patients were treated with the combined Er: YAG laser and HQ 4% on one side of the face with HQ 4% alone on the other side. Three sessions of the laser rat 4-week intervals. The outcome was calculated using the Melasma Area Severity Index (MASI).

Results: The side that received the combined treatment (laser + HQ 4%) showed a statistically significant reduction in MASI compared to the side treated with HQ 4% alone.

Conclusion: Our study suggests the superiority of the combination of the Er: YAG laser and HQ 4% in the treatment of melasma compared to HQ 4% alone. 

Background: The tooth root surfaces are modified by different agents for better removal of the smear layer, formation of fibrin clots and attachment of blood cells. This in vitro study compared removal of the smear layer, formation of fibrin clots and attachment of blood cells after exposing periodontally compromised root surfaces to ER:YAG and CO₂ laser beams.

Methods: Eighteen dentin block samples were prepared from freshly extracted periodontally compromised teeth that were deemed hopeless, and divided into 3 groups; exposed to Er:YAG laser beams, exposed to CO₂ laser beams and the control group. The samples were evaluated using scanning electron microscopy and micrographs were taken. Smear layer removal and blood cell attachment were scored. Data were analyzed with SPSS using Kruskal-Wallis and Mann-Whitney tests.

Results: In the Er:YAG laser group, the smear layer was removed completely. In the specimens exposed to blood, better fibrin clot formation and blood cell attachment were observed in the Er:YAG laser group. In the CO₂ laser group, the smear layer was also removed; however, there were no significant differences between the CO₂ laser and control groups in fibrin clot formation and blood cell attachment.

Conclusion: Application of Er:YAG laser to the root dentin appears to result in the formation of a suitable surface for fibrin clot formation and blood cell attachment. Further clinical studies are necessary to support these results.

Introduction: Bisphosphonates consist of a range of drugs used in the treatment of osteopathy or some osteotropic malignancies. Medication-related osteonecrosis of the jaws (MRONJ) is a serious adverse consequence from their use. Conventional treatment is not always effective, so it is necessary to resort to the use of adjuvant therapies. This study aimed to evaluate the effectiveness of the association of surgery, antibiotic therapy and low-level laser (LLL) therapy as a treatment strategy for MRONJ through the presentation of a clinical case.

Case presentation: A 49-year-old patient, female gender, presented for diagnosis and treatment of bone lesions in the maxillae. The patient reported that she had used zoledronate for one year. Five years later there were two painless bone lesions in both sides of maxilla, following extraction of the first upper molars. Clinical, tomographic and histopathologic examination established the diagnosis of MRONJ. The treatment consisted of curettage of necrotic bone, antibiotics and thirteen LLL therapy sessions. The integral mucosal healing was observed after two months of follow-up and no symptoms were detected. The patient was evaluated at six and 12 postoperative months without complications.

Conclusion: The combination of surgery, antibiotic therapy and LLL therapy has shown be effective in the treatment of MRONJ.

Juvenile hyaline fibromatosis (JHF) is an unknown hereditary disorder with variable penetrance. The characterizations of this disease consist of different signs and symptoms such as multiple tumorous (tumor-like) muco-cutaneous proliferation, gingival hypertrophy, perianal lesions, articular contractures, and osteolytic lesions. A 3-year-old girl with numerous painless nodular masses on her gingival, ear and anal areas is presented in this case report. Based on characteristic histological features, the diagnosis of JHF was made. The patient underwent surgery following general anesthesia and the above areas were surgically operated with appropriate laser parameters, and the patient was able to eat and wash away after a day and was discharged with an antibiotic prescription after one day in the hospital and returned to normal after a week. The recurrence occurred in other areas a year later, especially in the cheek, the ears and the anal area. Therefore, this rare case is presented with recurrence.

Behçet’s disease (BD) is a chronic, relapsing, systemic vasculitis of unknown etiology. Oral and genital aphthous ulcers are considered as the hallmarks of BD. The genital ulcers of BD may be extremely painful and often refractory to multiple treatments. In addition, they exert a negative impact on the patient’s quality of life. Some investigations have demonstrated the significant and immediate pain-relieving effects of NTCLT (non-thermal CO2 laser therapy) on some oral lesions with no visible adverse effects. In this paper, we report a case of BD whose painful genital ulcers were irradiated with NTCLT and the patient’s pain caused by the ulcers relieved immediately and significantly with no visible complications.

Introduction: The use of low-level laser therapy (LLLT) to treat wounds and accelerate tissue healing has been extensively studied in recent years. The aim of this article is to describe a clinical case using an unfocused high-power laser instead of a low-power laser for therapy. 

Case Report: In the present article, we present the use of a high-power diode laser to treat an extensive knee injury that occurred after surgical treatment for total prosthesis due to border ischemia resulting from prolonged use of autostatic retractors. 

Conclusion: It is possible to use an unfocused high-power laser at a decreased intensity to accelerate healing as an adjuvant in the treatment of complicated wounds. This procedure results in reduced application time and cost and an excellent tissue response pattern similar to that reported in the literature with low-power lasers.