Low level light therapy (LLLT) is known to accelerate the process of wound healing, bone and cartilage formation, and to decrease tissue necrosis and inflammation. It also can be applicable to acute and chronic injury or degenerative disease. Despite forty- plus years of accumulating exprerience of the clinical efficacy of LLLT, their molecular biologic evidence is not fully elucidated. The aim of this review is to explore the role of the ROS system and its molecular biologic mechanism in related with inflammatory response, anti-apoptosis and angiogenesis during LLLT. We suggest that activation of ROS system explains many (if not most) of the observed response of cells to LLLT in vitro, and is likely to play a pivotal role in the response of animals and patients to LLLT for both experimental and clinical indications and diseases.

Recurrence-metastasis status of squamous cell carcinoma of tongue is a challenging oncologic problem. This study examined the expression of E-cadherin/β-catenin cell adhesion complex in squamous cell carcinoma of the tongue through an immunohistochemical study. Twenty samples from 15 patients with squamous cell carcinoma of the tongue, who were treated at the Department of Oral and Maxillofacial Surgery, consisted of primary or recurrent tumors along with matched metastatic lymph nodes were retrieved for immunohistochemical staining and grouped based on recurrence-metastasis status.Differences in stain localization were noted in E-cadherin, β–catenin and phospho β–catenin staining between different tumor groups based on the recurrence-metastasis status. The number of phospho β-catenin stain positive cells was found to have a significant role in survival. E-cadherin confirms its role as a powerful individual differentiation indicator and the role of β-catenin specially the phospho type elicts interest

A blood test is a laboratory analysis performed on a blood sample that is usually extracted from a vein in the arm using a needle, or via fingerprick. They are used to determine physiological and biochemical states, such as disease, mineral contents, drug effectiveness, and organ function. Although the term blood test is used, most routine tests (except for most haematology) are done on plasma or serum, instead of blood cells. Main advantage of using saliva in diagnostics is easy and non invasive sample taking compared to peripheral blood. According to the study published, saliva contains more than 20 percent of the proteins found in blood. The purpose of present study is to compare biochemical enzymes in saliva and in blood serum and to evaluate the usefulness of saliva specimens instead of blood in dental clinic. The saliva from 215 healthy over 50 years of aged people lived in Dong-gu district, Gwangu city was collected and the analysis was performed by six enzyme-linked immunosorbent assays (ELISA). ELISA results were compared with blood chemistry results. The values or patterns on Alanine Aminotransperase (ALT), Aspartate Aminotransperase (AST), Cholesterol and Triglyceride in saliva were not correlated with those in blood serum. However, Albumine and γ-glutamyl transpeptidase (γ-GTP) were followed the positive relationship with blood chemistry. These result showed that detection and identification of Albumine and γ-GTP level could be established by saliva ELISA analysis, so that ELISA assay on saliva could be useful alternative to serum testing.

Diabetic patients tend to exhibit delayed bone formation and osteoblast differentiation, which results in osteopenia. Recently, numerous clinical reports suggest that 635-nm light irradiation improves bone regeneration and wound healing, and reduces pain in patients suffering from diabetes. The purpose of the present study was to test the hypothesis that 635-nm irradiation can influence bone formation by MC3T3-E1 osteoblasts cultured on high concentrations of glucose(25mmol/L D-glucose) in the presence or absence of phorbol 12-myristate 13-acetate(PMA), and to establish an in vitro pathological model of bone formation. The effect of 635-nm irradiation on bone formation was investigated using Alizarin Red S staining, and alkaline phosphatase enzyme activ ity and calcium deposition assays. In addition, gene expression of the o steogenic markers BMP-2, osterix and osteocalcin were assayed by RT-PCR. Calcium deposition by MC3T3-E1 cells was reduced in the presence of high concentrations of glucose or by PMA supplementation. However, 635-nm irradiation led to an increase in calcium deposition by MC3T3 cells, followed by increased bone mineralization. mRNA expression of BMP-2 and osterix at an early stage and of osteocalcin at a late stage was significantly upregulated by 635-nm irradiation in MC3T3-E1 cells supplemented with high concentrations of glucose. Irradiation at 635 nm increases bone mineralization in MC3T3-E1 cells cultured in vitro on high concentrations of glucose and alters osteogenic gene expression, which accelerates bone formation in hyperglycemic conditions.

Human gingival fibroblasts (hGFs) were reported to play an important role in inflammatory reactions to lipopolysaccharide (LPS) from P.gingivalis in the periodontal connective tissue. Although the biostimulatory effects of hyperbaric oxygen therapy, such as anti-inflammatory activity, have been reported, the pathological mechanism is not completely understood. This study examined the changes in the inflammatory cytokine profiles, which are produced after exposure to hyperbaric oxygen in P.gingivalis LPS-treated human gingival fibroblasts, and subsequently to examine the mitogen activated protein kinase (MAPK) pathway involved in cytokine production. Gingival fibroblasts with or without P.gingivalis LPS were exposed to hyperbaric oxygen, and the cytokine profiles in the supernatant were observed using a human inflammation antibody array. The expression of cyclooxyginase-2 (COX-2) protein, phosphorylation of extracellular signal-regulated kinase (ERK1/2), p38, and c-Jun-N-terminal kinase (JNK) MAPK by western blot analysis, and the amount of prostaglandin E2 (PGE2) in the supernatant by an enzyme-linked immunoassay were determined. COX-2 protein expression and PGE2productionwereincreasedsignificantlyintheP. gingivalis LPS-treated group, and were decreased by treating P. gingivalis LPS with hyperbaric oxygen. Treatment of P. gingivalis LPS in the gingival fibroblasts led an increase in the amount of pro-inflammatory-related cytokines interleukin-6 (IL-6) and IL-8 released, whereas hyperbaric oxygen inhibits the irrelease. Ananalysis of the MAPK signal transduction showed that hyperbaric oxygen induced a significant decrease in the level of P38 phosphorylation regardless of the presence or absence of LPS. In addition, hyperbaric oxygen promoted JNK phosphorylation, significantly in the presence of LPS. Hyperbaric oxygen can inhibit pro-inflammatory cytokines and mediate the MAPK signal pathway, and appears to be useful as an anti-inflammatory tool.

The pattern of wound healing process differs markedly according to the cell types. Gingival wounds heal more rapidly without scar, however dermal wounds show collagen laid down in thick disorganized patterns and keloid formation. This h as b een s uggested t o be d ue t o the presence of d ifferent E C M components a nd c ytokines a s well a s growth factors. The purpose of this study was to examine the differential expression of genes in connection with keloid formation in gingival fibroblasts (hGFs) and dermal fibroblasts (hDFs) in response to inflammation. In this study, we investigated the differences between hGFs and hDFs in the expression and production of cyclooxygenase (COX-2), prostaglandins E2 (PGE2), transforming growth factor (TGF)-β, collagens, matrix metalloproteinases (MMPs), and tissue inhibitors of matrix metalloproteinases (TIMPs) which play important roles in collagen deposition in wound healing. The hGFs and hDFs were primary cultured and allocated to arachidonic acid (AA) treatment group and control group. Protein and mRNA were extracted right after (0 hr) and 24 hr after AA treatment. At a defined concentration of AA in hGFs and hDFs, MTT assay was performed. The mRNA and protein expression levels of COX-2, TGF-β, collagen 1 and 3, MMP 1 and TIMP 1 were examined by Real-time PCR and Western blots. The amounts of PGE2 were measured by enzyme-linked immunosorbent assay (ELISA).The expression of COX-2 and TGF-β exhibited reduced levels in hGFs , but were increased in hDFs at 24 hr after AA treatment. Production of PGE2 was increased in hGFs and hDFs at right after AA treatment but, not changed at 24 hr after AA treatment. The protein and mRNA expression of collagen 1 and 3 were decreased in hGFs , whereas increased in hDFs at 24 hr AA treatment. Expression of MMP-1 protein was increased in hGFs at 24 hr but, was decreased in hDFs at 24 hr compared with that of control. The protein expression of TIMP-1 was decreased in hGFs but, was increased in hDFs at 24 hr compared with that of control. These observations demonstrate differential expression between gingival and dermal fibroblasts in regulation of collagenolytic capacity by extracellular matrix-associated genes in keloid formation associated with wound repair.

Candida albicans and their associated Candida species are opportunistic pathogens which exists as normal flora in the oral cavities of healthy individuals. In response to physiological changes in the host, these yeasts can become pathogenic, resulting in oral candidiasis. The rapid detection and identification of Candida species in clinical laboratories are extremely important for the management of patients with hematogenous candidiasis. The presently available culture and biochemical methods for detection and species identification of Candida are time-consuming and lack the required sensitivity and specificity. In this study, we have established a seminested PCR (snPCR) using universal and species-specific primers for detection of Candida species in saliva. The universal outer primers amplified the 3end of 5.8S ribosomal DNA (rDNA) and the 5end of 28S rDNA, including the internally transcribed spacer 2 (ITS2), generating 350- to 410-bp fragments from the four commonly encountered Candida spp., viz., C. albicans, C. tropicalis, C. glabrata, and C. parapsilosis. The saliva from 331 healthy and, over 50 years of aged people lived in Dong-gu, Gwangu city, was collected. Total DNA were extracted by Hoffman-Winston yeast total DNA prep. method and performed t he s nP CR. R esults appeared to b e negative on 292 people ( 88.2%), however, 2 6 people ( 7.9%) were p ositive Candida albicans, 6 people (1.8%) were positive Candida glabrata, 5 people (1.5%) were positive Candida tropicalis, and only 2 person (0.6%) were positive Candida parapsilosis. These result showed that detection and identification of Candida species could be established by saliva analysis, so that snPCR on saliva is useful method of diagnosis of clinical fields

Intracellular reactive oxygen species(ROS) produced in a various pathologic state was known to intermediate many cellular response such as inflammation. Recently, low level light irradiation by HeNe laser used in many clinical field could improve inflammatory state by scavenging intracellular ROS through photo-detachment/dissociation process. The purpose of this study is to investigate the differential effects of blue and red light irradiation on ROS scavenging effects. Immortalized human oral keratinocyte HaCat cells were used. Phorbol 12-myristate 13-acetate(PMA) was treated for inflammation. Red(635nm) and blue(470nm) light irradiation was carried out. To asses the intracellular ROS by light irradiation, confocal microscopic and flow cytometric assay with DCF fluorescence for total ROS and ESR spectrometry of DMPO-O2 - for superoxide anion were caried out. And microarray was performed for mRNA expression level. Released intracellular total ROS in PMA treated HaCat cell lines was dissociated efficiently by red light irradiation, while blue light irradiation did not. Rather, blue light irradiation increased ROS formation. For superoxide anion generated the first synthetic form of ROS, red light irradiation reduced its amount but blue light irradiation did not. In the mRNA expression in line with cyclooxygenase(COX) pathway, prostagrandin endoperoxide synthase 1(PTGS 1), prostagrandin endoperoxide synthase 2(PTGS 2) and phospholipase A2(PLA2) were increased by both light irradiation and they were decreased as time flows. And genes associated with ROS releasing, mRNA expressions of tumor necrosis factor receptor (TNFR) and interleukin 1beta(IL1B) were increased by 1 hour red light irradiation but did not by blue light irradiation. As a result, red and blue light irradiation showed different response in affecting the level of ROS. These findings indicate that red light rather than blue light is more useful for anti-inflammation in clinical field

The phytochemicals of many plants suggest their potential use as dietary supplements in cancer chemoprevention and chemotherapy. In the present study, antitumor activity of Cudrania tricuspidata, a plant native to East Asia, was investigated. Cell growth inhibition of the extract on HT-29 colorectal adenocarcinoma using MTT colorimetric assay was determined. Apoptosis on HT-29 cells was performed by DNA fragmentation analysis. PGE2 release was measured by enzyme immunoassay, because PGE2 is a key protumorigenic prostanoid in many human cancers. For the ROS scavenging activity, ROS level was detected by laser scanning confocal microscope. It was found that methanol extract of leaves inhibits cell viability by inducing apoptosis as evidenced by DNA fragmentation. Stem bark decreases synthesis of PGE2, inflammatory mediator. Fruits exhibited pronounced ROS scavenging activity. Taken together, these results suggest that Cudrania tricuspidata exerts growth inhibition and anti-oxidation on HT-29 cells through apoptosis, ROS scavenging respectively that it may have anti-cancer properties.

The purpose of the present study is to investigate the optimal wavelength, frequency and energy density for set up the photobiologic treatment of periodontal disease. To establish the present study, λ scan of 500㎚ to 900㎚ was used to search the optimal wavelength for maximal proliferation of human gingival fibroblasts. Cell proliferation assay was carried out as MTT assay. Light intensity of 0.8 to 3.25mW, frequency of 0 to 584㎐ and 0 to 2hours was applied for investigation of optimal energy density, frequency and applied duration. Finally, 628㎚ with 1mW/cm2 for 1hour of LED irradiation resulted in maximal proliferation of gingival fibroblasts. These results suggest that LED irradiation on gingival fibroblast show different proliferation according to the condition of irradiation, and demonstrate that LED irradiation can control the quantity of cell proliferation.

To investigate the differential expression of genes by 635nm LEDs irradiation in arachidonic acid-treated human gingival fibroblasts, cDNA microarray was carried out. Human gingival fibroblasts were primary cultured and arachidonic acid was treated to induce inflammation. 635nm of wave length was used for LEDs irradiation. The experimental group was categorized into four group ; control, only LEDs irradiation group, only arachidonic acid-treated group and arachidonic acid-treated with LEDs irradiation group. The expression of 8,078 genes were increased and the expression of 7,103 genes were decreased in only LEDs irradiation group. For arachidonic acid-treated with LEDs irradiation group, the expression of 6,815 genes were increased, while the expression of 8,031 genes were decreased comparing with only arachidonic acid-treated group. IL-13alpha2 receptor was the most expressed gene in LEDs irradiation group comparing with control, followed by MMP3. Genes which the most down regulated was BIRC3 in LEDs irradiation group. PLAB genes was the most up-regulated in arachidonic acid treated with LEDs irradation group, followed by ranked RARRES1. Considering the classification by cell function, genes associated with signal transduction were the most affected by LEDs irradiation, followed by the genes associated with nucleoside, nucleotide and nucleic acid metabolism. In arachidonic acid treated with LEDs irradiation, genes associated with signal transduction and protein metabolism were affected. Taken together, LEDs irradiation could affect various biological process and could identify many genes related to LEDs irradiation, which could be used for clinical application.

The process 0 1' wound healing needs the deposition of collagen and non-collagenous compounds, followed by the remodelling of extracellul ar matrix Recently, it has known that LEDs irradiation can help wound healing to accelerate the cell proliferation. But its mec hanism is not elucidated yot. The purpose of the present study is to observe the expression level of extracellular matrix by 635nm LEDs ir radiation. Human gingival fibroblasts were primary cultured, treated arac hidonic acid (때 and followed by LEDs irradiation. To observe the mRNA expression of extracellular matrix, cDNA mlcroarray was ca n‘ ied out 1n present study, 3 experimental groups were categorized into control, AA-treated group, and AA-treated with LEDs irradiation group. The differential expressions of MMP-1, -2, -3, - 10, - 11, -14, -16, - 17, -25 and TIMP-1, -2, -3. -4 were observed. Especially, mRNA expression of T1MP-3 was 10 fold decreased in arach idonic acid -treated with 635nm LEDs irradiation group. Finally, LEDs irradation can affect the expression level of MMPs and TIMPs, which lead to prolifer ation of gingival fibroblasts and result in would healing

The nitric oxide(NO) is a major factor contri buting to t he loss of neurons in ischemic st roke. demyelina t ing diseases, and other neurodegenerative di sorders . But it is known that NO is not function ing as a direct neurotoxin. NO combined with superoxide(02-) by the diffusion-contl'O ll ed reaction, formed a peroxin it ri te anion (ONOO-)‘ which this s pecies has been shown to contribute to oxidative s igna ling and damage. ONOO stimuJates apoptosis in many cell types. whether ONOO acts direct ly as an ox idant 0 1' the induction of apoptosis is because of the radicals derived from ONOO- decompositi on . But. the mecha ni sm by which ONOO- induces apoptosis is un clear although subsequent forrnation 0 1' reactive oxygen s pecies(ROS) has been suggested in a few reports The aim of this study is to investigate the a nti -apoptotic pathway by inhibi tion 0 1' ONOO synthesis t hrough scavenging of ROS us ing s pecific wavelength 0 1' light irradiation . The present study investi gated the a nti -apop totic effect of the specific wavelength 0 1' irradi ation in Sodium Nitroprusside(SNP) t reated SJ-I-SY5Y ceJls, by MTT, DNA fragmentation, and flow cytometric assay and th rough western blot and caspase-3, -9 activity assay for confirmation of caspase pathway. Also. NO reJease and ROS leveJ was measured in order to observe the changes of NO involved in radical by Griess reaction analysis and DCF'-DH. Results showed that the cell viability were r educed by about 50% of control group by SNP treatment, but re covered to about 80% by 590nm irradiation . The apoptotic cells were observed by flow cytomet ry and DNA fra g mentation assay in SNP-treated group‘ but 590nm irradiation led apoptotic feature to be reduced . Released NO a nd ROS level were increased after SNP treatment but ROS level was dec reased in 590nm irradi at ion - treated group, in spite of high NO concentration fo llowing SNP treatment Also. SNP t reatment led cytochrom C release but 590nm irraidiation inhibit it, hence the expression 0 1' caspase-3 and -9 was dec reased sign ificantly‘ These results showed that 590nm irradiation protect neuronal death thl'Ough bl ocking of NO-induced mi tochondri al apoptotic pathway. Also, it suggests that specific wavelength of irradi ation was used for prevent ion from neurodegenerative disordcr progression

It has been reported that light-emitting diodes(LED) can be used in the treatment of oral diseases. Although bio-stimulatory effects of LED irradiation such as promotion of wound healing have been well known, there are few reports about molecular mechanisms associated with wound healing by LED irradiation. The purpose of the present study was to investigate the expression pattern of various extracellular matrix(ECM) molecules in relation to wound healing after LED irradiation on primary human gingival fibroblasts(hGFs) in vitro. The source of light for irradiation was a continuous-wave LED emitting at a wavelength of 635 nm, and manufactured that energy density was 5 mW/cm2 on sample surfaces. The hGFs were irradiated for 1 hour at 37℃ in 5% CO2 humidified chamber. Experimental samples were acquired at 0 (right after irradiation), 24 and 48 hour after irradiation. To investigate the molecular mechanisms associated with wound healing, we examined the mRNA expression of 6 types of collagens, 7 types of matrix metalloproteinases(MMPs) and 4 types of tissue inhibition of metalloproteinases(TIMPs) after LED irradiation by RT-PCR. The mRNA expression of collagen 4, MMP-3, 9, and 16, and TIMP-3 was influenced by LED irradiation. Generally, the collagen expression of the irradiation group was slightly increased, particularly collagen 4 was significantly increased at 0 hour. The expression of MMP-3 was increased at 0 and 24 hours and MMP-16 was increased at 24 hours, respectively. The expression of MMP-9 was decreased at 0 hour and increased at 24 and 48 hours. The mRNA expression of TIMP-3 was significantly decreased at 24 and 48 hours after irradiation. These results suggest that the altered expression of ECM molecules after LED irradiation may contribute to the accelerated wound healing.

It has been reported that light-emitting diodes(LED) can be used in the treatment of oral diseases. Although bio-stimulatory effects of LED irradiation such as promotes stimulation of wound healing have been well known, there are few reports about molecular mechanism associated with cell cycle by LED irradiation. The purpose of present study was to examine the molecular event in cell cycle of LED irradiation on primary human gingival fibroblast(hGF) in vitro. The source of light for irradiation was a continuous-wave LED emitting at a wavelength of 635nm, and manufactured that energy density was 5mW/cm2 on sample surface. The hGF were irradiated for 1 hour at 37℃ in 5% CO2 humidified chamber. Experimental samples were acquired at 0 (right after irradiation), 8 and 24 hour after irradiation. To investigate the molecular mechanisms associated with cell cycle, growth phase was determined by flow cytometry and mRNA expression of cyclin A, cyclin B, cyclin D1, cyclin E, cdc2, PCNA, p18, p27, p21, and p53 were determined by real time RT-PCR. Flow cytometric analysis demonstrated the percentage of cells in the G1 and S phase were decreased, but the G2 phase increased, which showed cells irradiated by LED were transitioned from S to G2 phase. For mRNA expression, cyclin B, cdc2, PCNA and p53 were increased at 0 hour after irradiation, and most of cell cycle molecules were increased at 8 hour after irradiation. At 24 hour after irradiation, cyclin A, cyclin E, PCNA and p18 were increased. Taken together, LED irradiation induced proliferation of hGF cells through transition from S to G2 phase.

The purpose 01' pl'esent study was to examine the molecular events in apoptosis by CoCl2, mimicking hypoxic cond ition and recovering effects by LED ir l'adiation on Human SH-SY5Y neuroblastoma cells The SOUl'ce 0 1' light for ir l'adiation was a continuous-wave LED emitting at a wavelenl양h of 590 nm, and manufactured that ene rgy density was 5 mW!cm2 on sample surface, After ir l'adiation, cell viabi lity was measured with BrdU , cell morphol ogy was examined with Diff- Quik staining, cell signaling was monitored with various apoptosis-related molecules using RNase Pl'otection Assay(RPA) , W11en treated with CoC12, apoptotic induction was found in the SH-SY5Y cells in a concentration-dependent and time-dependent manner , Diff-Quik s taining was revealed that DNA fragmentation re presented apoptosis was examined in CoC12-tl'eated group, Moreover, RPA assay of SH-SY5Y cclls lIs ing val'iolls apoptosis-related molecllles showed that the apoptotic cell population was mcreased J-loweve. there was sorne signifïcant change in LED irradiatied cells aftel' treatement of CoC12 The main mechanism for Lhese a poptosis appearecl to be mito c hondriεt - m ecliated pathway, such as cytochrome- c‘ caspase-9, caspase-3, pro-apototic protein ßax, anti-apototic protein Bcl-2, and death receptor• mediated pathway, such as Fas, cas pase- 8, a ncl TNFRl These results demonstrate that CoCI2 induce apoptosis in SH-SY5Y via different dual apop tosis pathway through death receptor pathway as well as mitochondria- dependent pathway and LED irradiation can recl llces the CoCl2-induced apoptosis by blocking their internal signaling pathway

The number 01' patien ts with tongue carcinoma is increasing rapidly among young indiv idua ls in many parts of the worl d. Until now‘ most of studies were focused on the comparison malignancy wi th normal 01' dysplasia. There is little report of gene a lterations in normal to cancer , oral carcinogenesis. The purpose of present study is to evaluate the gene a ltc ration in every steps of oral carcinogenes is by DD- PCR. To induce tongue carcinoma in rat by 4- NQO. each dri nking water made 10ppm. 25ppm. 50ppm and control(o nly D.W without 4-NQO) . Specimens were classified into 4 groups s uch as co ntrol, I(mild & mocle rate dysplasia) , II(severe dysplasia and car cinoma in s itu) , III(carcinoma). Total RNA was ext racted and DD- PCR was performed using customized random primers. And to confïrmed t he results of DD-PCR‘ RT- PCR a nd real-time PCR with specific primers were carried out. There was phenotypic alteration in tongue 。f dosc a nd t imc dc pcndcnt man ncr. In gross examination, multiple papules, patch form or ulcerations were observed during 4 - NQO t reatment Hi s tologicall y, dysplasia was observed in 3 to 6 month and tumor formation in 6 to 8 month For DD-PCR, RT-PCR and real-time PCR, cyclophilin A, BAC RP23-372MB and BAC CH230-103E9 were differ entia lly expressed. Taken together, cyclophilin A has a role in all steps of oral carcinogenesis. BAC RP23-372N田is implica ted in carcinoma in s itu a nd BAC CH230-103E9 mRNA expression is assoicated with dysplasia and carcinom in s itu Conclus ively. some genes a re impli catcd a ll st eps of oral carci nogenesis, others are associated with one step, whi ch meant that genes are di fferentia lly expressed in every steps

LEDs have been shown to be a safe, efficient, light-weight, and less-expensive alternative to heal wound. LED irradiation at the same biostimulatory wavelength of previous laser studies have similar biochemical effects The purpose of present study is to evaluate the effects of wound healing by LED irradiation. Thirty 34-day-old sprague dawley were used for present study. 1.5mm diameter defected holes were formed in both ear lobes of rat by rubber dam punch. 635nm and 890nm irradiation was performed by LED for 2 weeks, followed by histologíc examination staíned with H&E and Masson trichrome. Also, RT-PCR was carried out to find out the mRNA expression level in gingival fjbroblast irradiated by 635nm for 1 hour. In gross exarnination, wound healing was observed in irradiated group comparing to control For microscopic exarnination, repair by connective tissues was filled in defects of irradiated group, while dense cellular bands consisting of fjbroblasts and capi llaries were found at the end of defect in control By staining of masson trichrome, amount of collagens were found in irradiated group. In a result of RT-PCR, mRNA expressions of TGF- ß , MMP-1,3 and Timp-3 were down-regulated in irradiated group comparing with their expression in control group. Taken together, LED irradiation increase the prolifeation and the activity of fibroblasts and down-regualted the TGF-ß , MMP- 1,3 and Timp- 3 mRNA, followed by activation of would healing.

μ방lt emitting diodes (LED) devices are commercially introduced as an alternative for low-Ievellaser therapy (11ι，T) ， and it has several advantages over lasers such as a safe, efficient, and less-expensive altemative to treat wounds. And LED irradiation at the same biostimulatory wavelength has similar bíochemical effεαs. In the present study, to asses whether the I핑ht-emitting diode (LED) irradíation can stimulate bone regeneration, irradiated bony defects with or without grafting materials on rat calvaria were compared to corresponding nonirradiated control. Fifty male Sprague-Dawly rats weighing about 150g, were used. Factors for present study were designed as follows, 1) presence or absence of grafting materials, 2) with or without irradiation, and 3) number of irradiation. Two weeks after operation, rats were sacrifìced. Radiologic and 비stomorphologic fmdings were evaluated. Macrospically, there were no incidents of infection, dehiscence, hematoma and necrosis during study. Radiological findings showed greater radiopacity in the graft group and radiopacity increased as the number of irradiation increase. And microscopically, new bαle formation was great in the graft group and increased as the number of irradiation increase, Present study has shown that LED irradiation improved bone regeneration through radiologic and histomorphologic fmdings in rat.