The Photobiomodulation effect of 980 nm Diode Laser on Patients with Xerostomia.

PURPOSE: Xerostomia is not a disease in itself. This condition is associated with systemic diseases, medication use, and radiotherapy. Oral and general health suffer when the salivary gland´s function is reduced. The effectiveness of therapeutic methods in resolving this issue thus far has been inadequate. This study aimed to determine the photobiomodulation (PBM) effect of a 980 nm laser on xerostomia. METHODS: A quasi-experimental study was carried out using a 980 nm diode laser on 28 patients with xerostomia. A diode laser (980 nm) was used extortionally over the submandibular glands and parotids and it was used internally in the sublingual glands. The laser beam (extrorally 6 J, 300mW, 20 s, and introrally 4 J, 200mW, 20 s) was applied bilaterally every other day for 10 sessions. It should be noted that 8 points of the parotid, 2 points of the submandibular glands, and 2 points of the sublingual glands were irradiated. The saliva was collected each session using the Navazesh technique, 5 min before and after PBM. The Wilcoxon test was used to study the effect of laser therapy on saliva flow rate (volume and weight). The P < 0.05 level was considered a significant level. RESULTS: The volume (P < 0.0001) and the weight (P < 0.0001) of the saliva were increased by using a 980 nm diode laser. While, in smokers and diabetic patients with hypertension, no significant difference was observed in either saliva volume (P = 0.593, P = 0.092) or weight (P = 0.785, P = 0.089). CONCLUSION: In this study, the volume and weight of the unstimulated saliva in most patients with xerostomia increased with using PBM.

Photobiomodulation for the management of xerostomia and oral mucositis in patients with cancer: a randomized clinical trial.

To evaluate the applicability of photobiomodulation therapy (PBM-T) in the management of xerostomia and OM. Fifty-three patients with head and neck squamous cell carcinoma were randomized into two groups: Sham and PBM-T. The Sham group received artificial saliva and laser simulation, while the PBM-T group received artificial saliva and PBM-T. Xerostomia-related quality of life (QoL), the presence or absence of OM lesions, the decayed-missing-filled teeth (DMFT) index, and periodontal charts were evaluated. The results of the QoL questionnaire, DMFT index, and periodontal chart were analyzed with the Kruskal-Wallis test, followed by the Student-Newman-Keuls test, while OM findings were compared using the Mann-Whitney test. QoL scores significantly increased in the Sham group (p < 0.0001), denoting more severe xerostomia symptoms (p = 0.0074), and decreased in the PBM-T group, indicating no or very mild xerostomia. Higher grades of OM were found in the Sham group than the PBM-T group (p = 0.0001). There was no significant difference in DMFT index or periodontal charts between the groups (p > 0.05). PBM-T improved QoL in patients with head and neck cancer treated with radiotherapy, whether as radiation alone or as an adjunct to chemotherapy and surgery.

[State of art of photobiomodulation in the management of radiotherapy adverse events: Indications and level of evidence]. / État de l'art de la photobiomodulation dans la prise en charge des effets secondaires de la radiothérapie : indications et niveaux de preuve.

PURPOSE: To evaluate the current and potential indications of photobiomodulation (PBM) and their level of evidence in the prevention or management of radiation therapy-related side effects. MATERIALS AND METHODS: The Embase, Medline/PubMed, Cochrane, EBSCO, Scopus, and LILACS databases were systematically reviewed to include and analyze publications of clinical studies that have assessed PBM in the prevention or management of radiotherapy-related side effects. The keywords used were "photobiomodulation"; "low level laser therapy"; "acute oral mucositis"; "acute dysphagia"; "acute radiation dermatitis"; "lymphedema"; "xerostomia"; "hyposalivation"; "trismus"; "bone necrosis"; "osteoradionecrosis"; and "radiation induced fibrosis". Prospective studies were included, whereas retrospective cohorts and non-original articles were excluded from the analysis. RESULTS: PBM in the red or infrared spectrum has demonstrated efficacy in randomized controlled trials in the prevention and management of radiotherapy-related side effects, especially acute oral mucositis, acute radiation dermatitis, and upper extremity lymphedema. The level of evidence associated with PBM was heterogeneous, but overall was still moderate. The main shortcomings were the diversity and lack of detail in treatment protocols, which could have compromised efficiency and reproducibility of PBM results. CONCLUSION: The published data suggest that PBM may be considered as a full-fledged supportive care for patients treated with radiotherapy, or at least in the setting of a therapeutic clinical trial. However, until strong evidence has been published on its long-term safety, the use of PBM should be considered with caution, specifically when applied near areas with proven or potential tumors. The patient should be informed of the theoretical benefits and risks of PBM in order to obtain his informed consent before treatment.

Evaluation of photobiomodulation in salivary production of patients with xerostomy induced by anti-hypertensive drugs: Study protocol clinical trial (SPIRIT compliant).

INTRODUCTION: Hypertension (systemic arterial hypertension [SAH]) is a systemic condition that affects about 30% of the world population, according to data from the World Health Organization (WHO). Drugs used to control this disease have the potential to induce xerostomia, an oral condition in which the decrease of the salivary flow is observed and whose presence leads to the increase of the index of caries, periodontal disease, loss of the teeth, dysgeusia, difficulty of mastication, dysphagia, bad breath and oral burning and impairment of prothesis installed in the buccal cavity, including retention of removable and total dentures. METHODS: This is a randomized, placebo-controlled, blind clinical protocol that aims to analyze the impact of phobiomodulation (PBM) on salivary glands of patients with antihypertensive drug induced xerostomia. Patients will be divided into 2 groups: G1: older adults with xerostomia induced by antihypertensive drugs and treatment with PBM (n = 30); G2: placebo PBM (n = 30). The irradiation will be made using a diode laser emitting at 808 nm with 100 mW and 40 seconds of exposure per site at the salivary glands. Twenty sites will be irradiated weekly for 4 weeks. Non-stimulated and stimulated salivary flow will be analyzed before and after the treatment. RESULTS: This protocol will determine the effectiveness of photodynamic therapy regarding the reduction of xerostomia in older adults using antihypertensive drugs. CONCLUSION: This protocol will determine the effectiveness of photodynamic therapy regarding the reduction of xerostomia in older adults using antihypertensive drugs. TRIAL REGISTRATION: Clinicaltrials.gov - NCT03632096.

Photobiomodulation Therapy in the Treatment of Oral Mucositis, Dysphagia, Oral Dryness, Taste Alteration, and Burning Mouth Sensation Due to Cancer Therapy: A Case Series.

Oral complications of cancer therapy, such as oral dryness, dysphagia, and taste alteration, are associated with a negative impact in the quality of life of the patients. Few supportive care measures are available for such complications. This case series reveals the effectiveness of the photobiomodulation (PBM) therapy when used in a specific protocol and parameters, in the management of oral complications related to cancer therapy. Dysphagia was measured using the functional outcome swallowing scale for staging oropharyngeal dysphagia (FOSS). Oral mucositis was measured according to the National Cancer Institute scale. The quantity of the whole resting and stimulated saliva was measured in order to assess the oral dryness. In addition, the taste alteration was measured according to a protocol suggested by the International Standards organization (ISO). Sensation of burning mouth was measured using a visual analogue scale. These measurements were made before treatment, during, and at the end of the treatment. Diode laser 635 nm was used in 3 J/cm2. Five sessions interleaved with 24 h breaks were conducted for the dysphagia and oral dryness, and 10 sessions were conducted for the taste alteration and burning mouth sensation. Regardless of the limitations of this case series, PBM can be considered safe, time saving, and a promising approach for the management of the oral complications due to cancer therapy and the quality of life of cancer patients.

Low-level laser therapy with 850 nm recovers salivary function via membrane redistribution of aquaporin 5 by reducing intracellular Ca2+ overload and ER stress during hyperglycemia.

The overall goal is to study the effect of low-level laser therapy (LLLT) on membrane distribution of major water channel protein aquaporin 5 (AQP5) in salivary gland during hyperglycemia. Par C10 cells treated with high glucose (50 mM) showed a reduced membrane distribution of AQP5. The functional expression of AQP5 was downregulated due to intracellular Ca2+ overload and ER stress. This reduction in AQP5 expression impairs water permeability and therefore results in hypo-salivation. A reduced salivary flow was also observed in streptozotocin (STZ)-induced diabetic mice model and the expression of AQP5 and phospho-AQP5 was downregulated. Low-level laser treatment with 850 nm (30 mW, 10 min = 18 J/cm2) reduced ER stress and recovered AQP5 membrane distribution via serine phosphorylation in the cells. In the STZ-induced diabetic mouse, LLLT with 850 nm (60 J/cm2) increased salivary flow and upregulated of AQP5 and p-AQP5. ER stress was also reduced via downregulation of caspase 12 and CHOP. In silico analysis confirmed that the serine 156 is one of the most favorable phosphorylation sites of AQP5 and may contribute to the stability of the protein. Therefore, this study suggests high glucose inhibits phosphorylation-dependent AQP5 membrane distribution. High glucose induces intracellular Ca2+ overload and ER stress that disrupt AQP5 functional expression. Low-level laser therapy with 850 nm improves salivary function by increasing AQP5 membrane distribution in hyperglycemia-induced hyposalivation.

Different Protocols of Photobiomodulation Therapy of Hyposalivation.

OBJECTIVE: Photobiomodulation (PBM) therapy has proved to be effective for a wide range of oral pathologies including oral dryness, but the literature still lacks reports of clinical trials and protocols. The purpose of our study was to evaluate the effects of different wavelengths of PBM on salivation in patients suffering from hyposalivation aiming at determination of optimal treatment protocol. MATERIALS AND METHODS: This study included 30 patients whose major salivary glands were treated with low-intensity diode laser BTL2000 (Medical Technologies, s.r.o., Czech Republic) during 10 consecutive days. Patients were randomly assigned into two groups, each of 15 patients, and treated with PBM of 830 nm and PBM of 685 nm, respectively. The whole unstimulated and stimulated saliva quantities were measured each day during 10 days, before and after laser treatment, and at 10th day after treatment was ended. RESULTS: Results have shown that the laser treatment significantly improves salivation (p < 0.0001) in both groups after 10 days treatment. The salivation also remains improved 10 days after the end of treatment. The patients treated with PBM of 830 nm have had continuously higher values of quantity of saliva. CONCLUSIONS: Our results have shown that both laser wavelengths were effective in increasing salivary flow rate, and the improvement in salivation was statistically significant. The effect of treatment could be observed 10 days after the completion of treatment, thus providing evidence not only of stimulative effect but also indicating regenerative potential of PBM therapy.

Impact of low-level laser therapy on hyposalivation, salivary pH, and quality of life in head and neck cancer patients post-radiotherapy.

Late effects of radiotherapy for head and neck cancer treatment have been increasingly investigated due to its impact on patients' quality of life. The purpose of this study was to evaluate the effect of low-level laser therapy on hyposalivation, low salivary pH, and quality of life in head and neck cancer patients post-radiotherapy. Twenty-nine patients with radiation-induced xerostomia received laser sessions twice a week, during 3 months (24 sessions). For this, a continuous wave Indium-Gallium-Aluminium-Phosphorus diode laser device was used punctually on the major salivary glands (808 nm, 0.75 W/cm2, 30 mW, illuminated area 0.04 cm2, 7.5 J/cm2, 10 s, 0.3 J). Six extraoral points were illuminated on each parotid gland and three on each submandibular gland, as well as two intraoral points on each sublingual gland. Stimulated and unstimulated salivary flow rate, pH (two scales with different gradations), and quality of life (University Of Washington Quality of Life Questionnaire for Patients with Head and Neck Cancer) were assessed at baseline and at the end of the treatment. There were significant increases in both mean salivary flow rates (unstimulated: p = 0.0012; stimulated: p < 0.0001), mean pH values (p = 0.0002 and p = 0.0004), and mean score from the quality of life questionnaire (p < 0.0001). Low-level laser therapy seems to be effective to mitigate salivary hypofunction and increase salivary pH of patients submitted to radiotherapy for head and neck cancer, thereby leading to an improvement in quality of life.

Low-level Laser Therapy: A Review of Its Applications in the Management of Oral Mucosal Disorders.

Due to its analgesic, anti-inflammatory, and biostimulating effects, low-level laser therapy (LLLT) has been widely used for oral disorders, such as oral lichen planus (OLP), xerostomia, recurrent aphthous stomatitis (RAS), herpes labialis, burning mouth syndrome (BMS), and oral mucositis (OM). The research team for the present study has reviewed the literature on the subject, with an emphasis on the applicability of LLLT in general and of its various clinical protocols for the management of those oral disorders. In lesions such as the ones occurring in OM, RAS, herpes labialis, and OLP, the course of wound healing and the pain have been shown to decrease, with a few, or most often, no adverse side effects. The literature shows that LLLT can also be effective in reducing symptoms in patients with BMS. For the treatment of hyposalivation and xerostomia, the use of LLLT has been described in the literature, but no consensus has resulted. Very few controlled clinical studies with well-established therapeutic protocols have occurred, except for OM, for which LLLT has been widely researched. Although information on the use of the laser for some lesions has already been consolidated, further research is needed, especially randomized, controlled clinical trials with long-term follow-up. Those studies will allow the safe use of LLLT, permitting the creation of care protocols for the management of oral disorders.

The Effectiveness of Low-Level Laser Therapy in Patients with Drug-Induced Hyposalivation: A Pilot Study.

OBJECTIVE: The aim of this study was to compare switched on and switched off (sham) low-level laser therapy (LLLT) in the treatment of drug-induced hyposalivation. BACKGROUND DATA: Hyposalivation is decreased salivary flow rate most frequently present in patients who take a lot of medication, suffer from Sjögren's syndrome, or were irradiated. Available therapies provide only short-term relief. MATERIALS AND METHODS: Forty-three participants (40 females and 3 males, average age 72.3 ± 8.9) participated in the study. Before therapy or after therapy, every participant fulfilled quality-of-life assessment scale (OHIP-CRO14). Unstimulated and stimulated salivary flow rates were measured before and after treatment. The LLLT was performed by the use of gallium-aluminum-arsenide (GaAlAs) laser (830 nm) on parotid, submandibular, and sublingual glands every day except during weekends for 14 days. RESULTS: Significant difference in unstimulated salivary flow rate after the treatment was found in the study group (p = 0.002) compared with the sham group. No significant difference in stimulated salivary flow rate after treatment was found in the laser group (p = 0.626) nor in the sham laser group (p = 0.233). No significant difference in patient's quality-of-life score was found after both treatments. CONCLUSIONS: The results of this study showed that the LLLT increased unstimulated salivary flow rate significantly. However, stimulated salivary flow rate did not increase significantly after the LLLT. In patients who underwent sham laser therapy, neither unstimulated nor stimulated salivary flow rate increased significantly.

Low-Level Laser for Mitigation of Low Salivary Flow Rate in Head and Neck Cancer Patients Undergoing Radiochemotherapy: A Prospective Longitudinal Study.

OBJECTIVE: The present study aimed to assess the impact of low-level laser (LLL) on low salivary flow rate in patients undergoing radiochemotherapy (RT-CT) for head and neck cancer. BACKGROUND DATA: LLL has shown efficiency in preventing hyposalivation in patients under different pathological conditions, including those undergoing RT-CT. METHODS: During all RT-CT, 17 patients received laser therapy and 10 received clinical care only. An Indium-Gallium-Aluminum-Phosphorus diode laser was punctually used for intraoral (660 nm, 40 mW, 10 J/cm(2), illuminated area 0.04 cm(2), 10 sec) and extraoral irradiation (780 nm, 15 mW, 3.8 J/cm(2), illuminated area 0.04 cm(2), 10 sec), three times a week and on alternate days, for a total of 21 sessions. Unstimulated salivary flow rate was assessed before the first RT session (N0), at the 15th RT session (N15), at the last RT session (Nf), and at 30 (N30) and 90 days after the end of the oncologic treatment (N90). RESULTS: At N15, Nf, and N30, patients treated with LLL showed significantly higher averages of salivary flow rate when compared with patients receiving clinical care only. CONCLUSIONS: LLL seems to be an efficient tool for mitigation of salivary hypofunction in patients undergoing RT for head and neck cancer.

Effect of low-level laser therapy on radiotherapy-induced hyposalivation and xerostomia: a pilot study.

OBJECTIVE: The present pilot study aimed to assess the effect of low-level laser therapy (LLLT) on hyposalivation and xerostomia as a consequence of head and neck radiotherapy. BACKGROUND DATA: The benefits of LLLT in salivary flow have been shown; however, there are no studies investigating its effects on patients who have already undergone radiotherapy and present hyposalivation and xerostomia as a sequela. METHODS: Twenty-three patients with a history of head and neck malignancy, who were treated by fractioned teletherapy (dosimetry ranging from 45 to 70 Gy) in the cervicofacial region were selected. They all presented with xerostomia and severe hyposalivation. Patients were randomly distributed into a laser group (n=12) and a control group (n=11). A GaAlAs laser (830 nm, 100 mW, illuminated area 0.028 cm2, 3.57 W/cm2, 20 sec, 2.0 J, 71 J/cm2) was used punctually in the major salivary glands, twice a week for 6 weeks, with a 12 session total. Stimulated and unstimulated salivary flow rate (SFR) were assessed, as well as the xerostomia and quality of life related to oral health (QLROH). RESULTS: The analysis did not show any significant difference between the groups with regards to the SFR and xerostomia, and the QLROH. However, at the end of the treatment, the xerostomia and the QLROH showed significant improvement in both groups compared with assessments performed at baseline, highlighting the importance of advice given to the irradiated patients, and their follow-up. CONCLUSIONS: With the parameters used, LLLT was not able to increase SFR or decrease xerostomia. The results may be associated with the late effects of radiotherapy on glandular structure, such as fibrosis and acinar atrophy.

[The effects of low-level laser therapy on xerostomia (mouth dryness)].

INTRODUCTION: Xerostomia is a subjective complaint of mouth/oral dryness, caused by a reduction in normal salivary secretion due to different causes. Even though there are many available treatment modalities to enhance salivary flow, the therapy often remains unsatisfactory. The low-level laser therapy (low-level laser irradiation, photo-biomodulation) has been extensively used as a new, non-invasive approach and advantageous tool for reduction of xerostomia. Therefore, the aim of this study is to give a systematic overview on the effects of low-level laser therapy on xerostomia. MATERIAL AND METHODS: A systematic review of published articles in PubMed database was carried out using keywords: "low-level laser therapy", "xerostomia", "mouth dryness". RESULTS: In all published articles, which were considered adequate for this overview, positive effects of low-level laser therapy were reported. Low-level laser therapy could significantly enhance salivary secretion and improve antimicrobial characteristics of secreted saliva (increased level of secretory immunoglobulin A; sIgA). Furthermore, low-level laser therapy could improve salivary flow and regeneration of salivary duct epithelial cells. CONCLUSION: The current literature suggests that low-level laser therapy can be safely and effectively used as an advanced treatment modality for reduction of xerostomia. Further in vivo, in vitro and clinical studies using different irradiation parameters are suggested to determine the best laser parameters to be used.

The effect of low-level laser therapy on salivary glands in patients with xerostomia.

OBJECTIVE: The aim of this study was to investigate the effect of low-level laser irradiation on the secretory function of salivary glands in 34 patients with xerostomia (dry mouth). BACKGROUND DATA: Xerostomia, a common complaint of oral dryness within the elderly population, is caused by a reduction in normal salivary secretion due to different causes. Treatment is aimed at increasing salivary flow, although in most cases it remains palliative. MATERIALS AND METHODS: In this study, laser light from a pulsed Ga-As laser operating at 904 nm was applied bilaterally on each salivary gland area: extraorally on the parotid and submandibular gland areas and intraorally on the sublingual gland area. The operational probe distance from the irradiated area was 0.5 cm resulting in an irradiance of 246 mW/cm(2). The exposure time was 120 sec per daily treatment during 10 consecutive days. The average energy density per exposure was 29.5 J/cm(2). The control group consisted of 16 patients who were treated with 15 mL of a 2% citric acid solution applied as a mouth rinse for 30 sec. RESULTS: The average difference in the amount of salivation (dQ-sal, mL/min) before and after laser therapy increased linearly from dQ-sal = 0.05 mL/min on the first day, up to dQ-sal = 0.13 mL/min on the last (10th) day of therapy. In the control group, the average dQ-sal initially demonstrated a gradual increase, with a reversal of the trend toward the end of the therapy period and eventually yielding no correlation between the duration of therapy and dQ-sal. CONCLUSION: The results of our study indicate that the effects of low-level laser therapy on salivary glands are not only stimulating, but also regenerative to a degree since the glandular response to the same amount of applied laser energy increased linearly over time.

Effects of low-level laser treatment on mouth dryness.

UNLABELLED: Mouth dryness (MD) is usually followed by inadequate mechanical cleaning of the mouth and decrease in the levels of salivary antimicrobial proteins (including secretory immunoglobulin A (sIgA)). It is accompanied by difficulties during speaking and food swallowing, with an unpleasant taste, burning sensations in the mouth and higher susceptibility to oral diseases. Low-level laser treatment (LLLT) can intensify cell metabolism and its application on salivary glands could improve salivation. The purpose of this study was to evaluate the effects of LLLT on salivation of patients suffering from MD. The study included 17 patients with MD. Their major salivary glands were treated with low intensity laser BTL2000 on 10 occasions. The whole unstimulated and stimulated saliva quantities were measured just before the 1st, after the 10th and thirty days following the last (10th) treatment. In the samples of unstimulated saliva concentrations of sIgA were estimated by using ELISA method and its quantity in the time unit was calculated. The visual analogue scale (VAS) score was used to assess burning and/or pain intensity at these three time points. Statistical tests revealed significant salivation improvement quantitatively and qualitatively, i.e. increase in the quantity of saliva and sIgA. VAS score was also significantly improved and no side effects were observed. CONCLUSIONS: According to the results of this study, application of LLLT to xerostomic patients' major salivary glands stimulates them to produce more saliva with better antimicrobial characteristics and improves the difficulties that are associated with MD. This simple non-invasive method could be used in everyday clinical practice for the treatment of MD.

Laser as a therapy for dry mouth symptoms in a patient with Sjögren's syndrome: a case report.

This clinical case study reports on dry mouth symptoms in a patient with Sjögren's syndrome (SS) who was treated with laser phototherapy (LPT). A 60-year-old woman diagnosed with SS was referred to the laboratory for lasers in dentistry to treat her severe xerostomia. A diode laser (780 nm, 3.8 J/cm2, 15 mW) was used to irradiate the parotid, submandibular, and sublingual glands, three times per week, for a period of 8 months. The salivary flow rate and xerostomia symptoms were measured before, during, and after LPT. Dry mouth symptoms improved during LPT. After LPT, the parotid salivary gland pain and swelling were no longer present. Treatment with LPT was an effective method to improve the quality of life of this patient with SS.

Improvement in quality of life of an oncological patient by laser phototherapy.

OBJECTIVE AND BACKGROUND DATA: Common side effects of radiotherapy (RT) to the head and neck include oral mucositis, xerostomia, and severe pain. The aim of this study is to report improvement in the quality of life of an oncological patient by laser phototherapy (LPT). CLINICAL CASE AND LASER PHOTOTHERAPY PROTOCOL: The patient, a 15-year-old girl diagnosed with mucoepidermoid carcinoma, underwent surgical excision of a tumor of the left palatomaxilla. After that, she was subjected to 35 sessions of RT (2 Gy/d). Clinical examination revealed the spread of severe ulcerations to the jugal mucosa, gums, lips, hard palate, and tongue (WHO mucositis score 3). She had difficulty in moving her tongue and she was unable to eat any solid food. Oral hygiene orientation and LPT were performed throughout all RT sessions. A continuous diode laser, 660 nm, 40 mW, 6 J/cm(2), 0.24 J per point in contact mode, with spot size of 0.04 cm(2) was used in the entire oral cavity. A high-power diode laser at 1 W, 10 sec per cm of mucositis, approximately 10 J/cm(2), was used in defocused mode only on ulcerative lesions. After the first laser irradiation session, decreases in pain and xerostomia were reported; however, a more significant improvement was seen after five sessions. At that point although the mucositis score was still 2, the patient reported that she was free of pain, and consequently a palatine plate could be made to rehabilitate the entire surgical area. Seventeen laser irradiation sessions were necessary to eliminate all oral mucositis lesions. CONCLUSION: Normal oral function and consequent improvements in the quality of life of this oncologic patient were observed with LPT.

Effect of diode laser on enzymatic activity of parotid glands of diabetic rats.

The aim of this study was to evaluate the effect of laser irradiation (LI) on enzymatic activities of amylase, catalase and peroxidase in the parotid glands (PG) of diabetic and non-diabetic rats. Ninety-six female rats were divided into eight groups: D0; D5; D10; D20 and C0; C5; C10; C20, respectively. Diabetes was induced by administration of streptozotocin and confirmed later by the glycemia results. Twenty-nine (29) days after the induction, the PGs of groups D5 and C5; D10 and C10; D20 and C20, were irradiated with 5 J/cm(2), 10 J/cm(2) and 20 J/cm(2) of laser diode (660 nm/100 mW) respectively. On the following day, the rats were euthanized and the enzymatic activity in the PGs was measured. Diabetic rats that had not been irradiated (group D0) showed higher catalase activity (P < 0.05) than those in group C0 (0.14 +/- 0.02 U/mg protein and 0.10 +/- 0.03 U/mg protein, respectively). However, laser irradiation of 5 J/cm(2) and 20 J/cm(2) decreased the catalase activity of the diabetic groups (D5 and D20) to non-diabetic values (P > 0.05). Based on the results of this study, LI decreased catalase activity in the PGs of diabetic rats.

Prevenção da xerostomia e da mucosite oral induzidas por radioterapia com uso do laser de baixa potência / Low level laser therapy in the prevention of radiotherapy-induced xerostomia and oral mucositis

OBJETIVO: Verificar se o uso do laser de InGaAlP com comprimento de onda de 685 nm pode reduzir a incidência de xerostomia, gravidade da mucosite oral e da dor associada à mucosite em pacientes portadores de câncer de cabeça e pescoço submetidos a radioterapia. MATERIAIS E MÉTODOS: Sessenta pacientes portadores de carcinoma de cabeça e pescoço foram submetidos a radioterapia com dose diária de 1,8 a 2,0 Gy e dose final de 45 a 72 Gy. O volume salivar foi medido nos dias um, 15, ao final do tratamento e após 15 e 30 dias, e a mucosite oral em avaliações semanais. Vinte e nove pacientes se submeteram a radioterapia sem laser e 31 foram submetidos a radioterapia e laser com dose diária de 2 joules/cm² em pontos pré-determinados da mucosa oral e glândulas parótida e submandibular. RESULTADOS: No grupo submetido a radioterapia e laser, a incidência de mucosite (p < 0,001) e dor (p < 0,016) foram significativamente menores e o volume salivar se manteve maior (p < 0,001) durante e após o tratamento. CONCLUSAO: Os pacientes submetidos à associação de radioterapia e laser tiveram menor incidência de xerostomia, mucosite oral e dor quando comparados ao grupo de radioterapia sem laser, com resultados com significância estatística.