Journal of Lasers in Medical Sciences

Treatment protocols with low-level Laser (also called ‘soft laser therapy) have been used in health care systems for more than three decades. Bearing in mind the suitable sub-cellular absorption and the cellular-vascular impacts, low-level laser may be a treatment of choice for soft tissues. Low-level lasers have played crucial and colorful roles in performing periodontal surgeries. Their anti-inflammatory and painless effects have been variously reported in in-vitro studies. In this present review article, searches have been made in Pub Med, Google Scholar, and Science Direct, focusing on the studies which included low-level lasers, flap-periodontal surgeries, gingivectomy, and periodontal graft. The present study has sought to review the cellular impacts of low-level lasers and its role on reducing pain and inflammation following soft tissue surgical treatments.   

In the surgical treatment of malignant tumors, it is crucial to characterize the tumor as precisely as possible. The determination of the exact tumor location as well as the analysis of its properties is very important in order to obtain an accurate diagnosis as early as possible. In neurosurgical applications, the optical, non-invasive and in situ techniques allow for the label-free analysis of tissue, which is helpful in neuropathology. In the past decades, optical spectroscopic methods have been investigated drastically in the management of cancer. In the optical spectroscopic techniques, tissue interrogate with sources of light which are ranged from the ultraviolet to the infrared wavelength in the spectrum. The information accumulation of light can be in a reflection which is named reflectance spectroscopy; or interactions with tissue at different wavelengths which are called fluorescence and Raman spectroscopy. This review paper introduces the optical spectroscopic methods which are used to characterize brain tumors (neuro-oncology). Based on biochemical information obtained from these spectroscopic methods, it is possible to identify tumor from normal brain tissues, to indicate tumor margins, the borders towards normal brain tissue and infiltrating gliomas, to distinguish radiation damage of tissues, to detect particular central nervous system (CNS) structures to identify cell types using particular neurotransmitters, to detect cells or drugs which are optically labeled within therapeutic intermediations and to estimate the viability of tissue and the prediction of apoptosis beginning in vitro and in vivo. The label-free, optical biochemical spectroscopic methods can provide clinically relevant information and need to be further exploited to develop a safe and easy-to-use technology for in situ diagnosis of malignant tumors.

Introduction: The aim of this study was to evaluate and compare microhybride composite treated by bur and different power of Erbium, Chromium doped Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) laser by Scanning Electron Microscope (SEM).

Methods: 21 microhybride composite blocks (DiaFil TM, DiaDent, Korea) with 2 × 4 × 4 mm dimensions were made. The bonding surface of these blocks were polished, The samples were put into 6 groups for laser irradiation as follows: Group 1 (power: 1W, Energy: 50 mJ); Group 2(power: 2 W, Energy: 100mJ); Group 3 (power: 3W, Energy: 150mJ); Group 4 (power: 4W, Energy: 200mJ); Group 5 (power: 5W, Energy: 250mJ) and Group 6(power:6 W, Energy :300mJ). One group prepared by bur- treated. All samples were prepared by repetition rate of 20 Hz. Then, the samples were prepared for SEM examination.

Result: Some irregularities were seen in Er,Cr:YSGG laser samples in comparison to Bur group that produced favorable surface for adhesion of repair composite.

Conclusion: Among different lasers, Er;Cr:YSGG laser can be chosen as a suitable technique for surface treatment of unsatisfactory composites.

Key words: SEM evalution; laser; composite resin

In this study, laser induced breakdown spectroscopy (LIBS) is used for qualitative analysis of healthy and carious teeth. The technique of laser ablation is receiving increasing attention for applications in dentistry, specifically for the treatment of teeth such as drilling of micro-holes and plaque removal. In the process of ablation a luminous micro-plasma is normally generated which may be exploited for on-line elemental analysis via laser induced breakdown spectroscopy technique. We propose laser induced breakdown spectroscopy as a rapid, in situ and easy method for monitoring drilling process. The results of elemental analysis show the presence of some trace elements in teeth including P, Ca, Mg, Zn, K, Sr, C, Na, H, O and the permeability of some amalgam (teeth filling materials) elements including Hg, Ag, Cu and  Sn into dental matrix. This study address the ability of LIBS in elemental analysis of teeth and its feasibility in acute identification of healthy and carious teeth during drilling process for future clinical applications.

Introduction: Laser phototherapy is used for the treatment of chemotherapy-induced oral mucositis in patients with leukemia, although there are limited data supporting the safety of this method. This study aimed to evaluate the effect of different doses of low-level laser on proliferation of acute myeloid leukemia (AML) cell line (KG-1a) in vitro.

Methods: A plastic flask containing 5,000,000 KG-1a cultured cells was provided by Iran Pasteur Institute. KG-1a cell line has been produced from the bone marrow aspirate of a 59-year-old white male with acute myelogenous leukemia. Upon completion of the proliferation steps of KG-1a cell line, 7×10⁴ cells were placed in 96-well tissue culture plates. All the surrounding wells were filled with Wright-Giemsa stain in order to prevent laser from scattering to the neighboring wells. In total, 28 plates were prepared using this method. After a forty-eight hours incubation period, irradiation was performed in continuous mode with an infrared laser of 810nm wavelength. After 24 hours, cells cultures were exposed to one, two, or three applications of laser irradiation. Irradiation exposures were performed at energy densities of 5, 10, and 20 J/cm2. Each experiment included 18 replicates for each application of laser and 6 replicates of negative/untreated controls. For experiments with two and three repeated exposures, the irradiation applications were separated by 48 hours. All the culture plates were incubated for seven days. Cell proliferation was evaluated using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide)  assay after seven days. Spectroscopy (620nm) was used to determine the optical density (OD) of both irradiated and control samples.

Results: Significant increase in cell proliferation was seen only after two exposures at energy density of 20J/cm² (P=0.021).

Conclusion: Although LLLT is commonly used to treat radiotherapy- or chemotherapy- induced mucositis, as long as further studies demonstrate that different wavelengths and doses of laser phototherapy are safe and effective in treatment of mucositis, clinicians should remain cautious regarding the use of this treatment modality to treat patients with malignancies.

Introduction: The aim of this study was to evaluate the composite surface treated by different powers of Erbium-Doped Yttrium Aluminum Garnet (Er:YAG) laser in comparison with bur preparation via scanning electron microscope.

Methods: Fourteen composite resin blocks with 15× 10 × 10 mm dimensions were used in this study. The samples were divided to seven groups as follow: Group 1 (power: 1 W, Energy: 50 mJ); Group 2 (power: 2 W, Energy: 100 mJ); Group 3 (power: 3W, Energy: 150 mJ); Group 4 (power: 4 W, Energy: 200 mJ); Group 5 (power: 5W, Energy: 250 mJ); Group 6 (power: 6 W, Energy: 300 mJ); Group 7: Diamond bur. Then, the samples were prepared for SEM examination.

Results: The surface treated by Er:YAG laser showed irregular and micro porous surface.

Conclusion: It seems that composite surface treatment by Er:YAG laser can be an alternative method for composite repair if suitable parameters are used.

Introduction: Dentin hypersensitivity is one of the most common complications that affect patients after periodontal therapy. Recently low level laser therapy has been introduced as a new treatment modality and has produced beneficial results. The purpose of this study is to evaluate the effect of low level laser therapy toothbrushes in reduction of dentin hypersensitivity.

Methods: In this pilot interventional controlled clinical trial, 40 patients suffering from dentin hypersensitivity were selected using simple randomization. Half of the patients were given laser toothbrushes and the other half was given non-laser sensodyne toothbrushes. Primary dentin hypersensitivity was recorded by visual analogue scale (VAS) score and ice spray. Then dentin hypersensitivity was measured right after the treatment as well az in the intervals of 1 month and 2 months after initiation of the study. Data were compared using Statistical Package for the Social Sciences (SPSS) software and Analysis of variance (ANOVA) paired T test.

Results: The results of this study showed that there was a significant difference in each of the two kinds of tooth brushes separately for all time intervals (P < 0.001). Also the effect of the type of toothbrush was investigated using before treatment VAS with covariance analyses. P values for immediately, 1 month and 2 months after treatment were calculated to be 0.078, 0.02, 0.01 respectfully.

Also the effect of the toothbrush type was significant in the manner that laser toothbrushes reduce dentin hypersensitivity more than ordinary toothbrushes (P< 0.05).

Conclusion: Both sensodyne and laser tooth brushes improve dentin hypersensitivity, although the laser toothbrush led to better results in short.

Results and conclusion: Lasers are useful for soft tissue surgery in modern dentistry, especially in relation to pediatric patients due to the rapid and regular wound healing without sutures.

Introduction: Epulis granulomatosa is a lesion which grows from an extraction socket. It can be misdiagnosed with lesions of the same clinical appearance such as: foreign body or pyogenic granuloma, or as a herniation of the maxillary sinus. The most common treatment is surgical excision.

 Case report: The present article reports an Epulis granulomatosa which was removed with diode laser (810 nm) due to child’s fear related to traditional surgical instruments and bleeding.