Low level lasers in dentistry

Low level laser therapy (LLLT) uses light energy, in the form of adenosine triphosphate (ATP), to elicit biological responses in the body. The increased cellular energy and changes in the cell membrane permeability result in pain relief, wound healing, muscle relaxation, immune system modulation, and nerve regeneration. This article investigates the clinical effects of LLLT and explains how it can be applied in the dental field.

Suppressing effect of low-dose gamma-ray irradiation on collagen-induced arthritis

We previously reported attenuation of autoimmune disease by low-dose gamma-ray irradiation in MRL-lpr/lpr mice. Here, we studied the effect of low-dose gamma-ray irradiation on collagen-induced arthritis (CIA) in DBA/1J mice. Mice were immunized with type II collagen, and exposed to low-dose gamma-rays (0.5 Gy per week for 5 weeks). Paw swelling, redness, and bone degradation were suppressed by irradiation, which also delayed the onset of pathological change and reduced the severity of the arthritis. Production of tumor necrosis factor-alpha, interferon-gamma, and interleukin-6, which play important roles in the onset of CIA, was suppressed by the irradiation. The level of anti-type II collagen antibody, which is essential for the onset of CIA, was also lower in irradiated CIA mice. The population of plasma cells was increased in CIA mice, but irradiation blocked this increase. Since regulatory T cells are known to be involved in suppression of autoimmune disease, the population of CD4(+)CD25(+)Foxp3(+) regulatory T cells was measured. Intriguingly, a significant increase of these regulatory T cells was found in irradiated CIA mice. Overall, our data suggest that low-dose gamma-ray irradiation could attenuate CIA through suppression of pro-inflammatory cytokines and autoantibody production, and induction of regulatory T cells.

Development of samarium [32P] phosphate colloid for radiosynoviorthesis applications: Preparation, biological and preliminary clinical studies experience

A new therapeutic radio colloid for radiosynoviorthesis (RS) applications is reported. The method of preparation involves the reaction of SmCl3 carrier with carrier added [32P]H3PO4 in the presence of gelatin. The pure colloid was recovered by dialysis purification leading to radiochemical yield of around 90%. The radiochemical purity of the pure colloid formulated in isotonic saline was over 98%, for the usage period of 14 days, as assessed by paper chromatography. Ninety percent of colloid particles were in the size of 1-10 microm as evident from the laser diffraction particle size analysis, ideally suitable for the intended end use. Animal studies revealed complete retention of the radio colloid in the rabbit knee joint. The results of clinical trials in humans are satisfactory and encouraging, satisfactory retention of the colloid in the knee joint and negligible leakage into the systemic circulation.

Die Radiosynoviorthese im orthopädischen und rheumatologischen Alltag

Radionuclide synoviorthesis (RSO) is a local radiotherapy that can be used in cases of synovialitis. RSO is performed by intraarticular injection of beta emitters (Er-169, Re-186, Y-90). Before RSO is planned, a precise indication is necessary, which must be verified by the acting nuclear physician, preferably using soft-tissue scintigraphy. If RSO is handled in an interdisciplinary fashion, it will be a valuable tool in the treatment of synovialitis.

The intra-articular distribution of 90yttrium does not influence the clinical outcome of radiation synovectomy of the knee

OBJECTIVES

To assess the impact of the intra-articular distribution of (90)yttrium-citrate ((90)Y) on the clinical effect of radiosynoviorthesis (RSO) of the knee and on (90)Y leakage from this joint.

METHODS

Patients with arthritis of the knee received 185 MBq (90)Y combined with a glucocorticoid, followed by clinical bed rest. Intra-articular (90)Y distribution, measured with a dual-head gamma camera immediately or after 24 hours, was scored as mainly diffuse or mainly focal. Leakage to regional lymph nodes, the liver and spleen was assessed with a dual-head gamma camera after 24 hours. Clinical effect was scored after 6 months by a composite change index (CCI), range 0-12; responders were defined as having a CCI > or =6.

RESULTS

Seventy-eight knees of 69 patients, mostly suffering from undifferentiated arthritis (42%) or RA (28%), were treated. (90)Y distribution was mainly diffuse in 54% and mainly focal in 46% with clinical response rates of 40% versus 56%, respectively, p = 0.3. CCI was not correlated with distribution. (90)Y leakage was found only to the liver and the spleen (mean leakage 0.4% and 1.1%, respectively). Leakage was significantly less in case of diffuse intra-articular (90)Y distribution, whereas leakage to the liver was correlated with distribution (r = 0.68, p<0.001). (90)Y leakage was not correlated with CCI.

CONCLUSIONS

Intra-articular (90)Y distribution does not influence the clinical effect of RSO of the knee. Although (90)Y leakage from the joint is less if (90)Y distributes diffusely in the joint cavity, leakage does not seem to hamper the clinical effect.

In vivo study of the inflammatory modulating effects of low-level laser therapy on iNOS expression using bioluminescence imaging

This study was designed to demonstrate that bioluminescence imaging (BLI) can be used as a new tool to evaluate the effects of low-level laser therapy (LLLT) during in vivo inflammatory process. Here, the efficacy of LLLT in modulating inducible nitric oxide synthase (iNOS) expression using different therapeutic wavelengths was determined using transgenic animals with the luciferase gene under control of the iNOS gene expression. Thirty transgenic mice, FVB/N-Tg(iNOS-luc)Xen, were allocated randomly to one of four experimental groups treated with different wavelengths (lambda = 635, 785, 808 and 905 nm) or a control group (nontreated). Inflammation was induced by intra-articular injection of zymosan A in both knee joints. Laser treatment (25 mW cm(-2), 200 s, 5 J cm(-2)) was applied to the knees 15 min after inflammation induction. Measurements of iNOS expression were performed at various times (0, 3, 5, 7, 9 and 24 h) by measuring the bioluminescence signal using a highly sensitive charge-coupled device (CCD) camera. The results showed a significant increase in BLI signal after irradiation with 635 nm laser when compared to the nonirradiated animals and the other LLLT-treated groups, indicating wavelength dependence of LLLT effects on iNOS expression during the inflammatory process, and thus demonstrating an action spectrum of iNOS gene expression following LLLT in vivo that can be detected by BLI. Histological analysis was also performed and demonstrated the presence of fewer inflammatory cells in the synovial joints of mice irradiated with 635 nm compared with nonirradiated knee joints.

Perspektiven der Strahlentherapie gutartiger Erkrankungen

PURPOSE

The numbers of patients with nonmalignant diseases referred for radiation therapy had to be evaluated for the last 4 years.

PATIENTS AND METHODS

In the years 2002, 2004, and 2005 radiation therapy was performed in 61, 40, and 26 patients, respectively. Regularly, more women than men were treated, median age annually was 57, 54, and 55 years, respectively (Table 1). The radiotherapy scheme was not modified within the evaluated period.

RESULTS

The proportion of nonmalignant diseases among all patients treated decreased from 4.7% in 2002 to 3.3% in 2004 and 2.2% in 2005, respectively. A shift was noticed toward the treatment of four main diseases (endocrine orbitopathy, prevention of heterotopic ossification, meningeoma, tendinitis, Table 2). The number of referring physicians decreased from 19 to six.

CONCLUSION

Due to administrative restrictions for treatment in hospitals, budget restrictions in private practices and lasting, insufficient revenues for radiotherapy in nonmalignant diseases, radiation therapy for the entire group of benign diseases is endangered.

Radiosynoviorthese

Intraarticular therapy is an established form of therapy in chronic inflammatory joint diseases. Besides the injection of glucocorticoids, radiosynoviorthesis is a frequently used procedure. Intraarticular injected beta-emitting radionuclides are indicated in chronic synovitis with recurrent joint effusions in rheumatoid arthritis, seronegative spondyloarthritis, villonodular synovitis after surgery and for bleeding prophylaxis in haemophilic arthropathy. The value of radiosynoviorthesis in activated osteoarthritis is not yet clarified.

Ungewöhnliche Fingergelenkdestruktionen nach Radiosynoviorthese (RSO) und Cortisoninjektionstherapie bei Bouchard-Arthrose

Starting in 1998, a female patient suffering from activated Bouchard arthrosis was treated with intra-articular steroid injections into digits of both hands. In September 2001, an additional therapy with erbium-169 injections into the same joints was begun. The injections were continued until March 2003. No benefit was observed. Instead, severe destruction of the involved joints with articular necroses and marked periarticular calcifications had occurred. The course of events are documented by plain film examinations.

CONCLUSIONS

The indication for alternating steroid injections and radio-synovectomies in patients with activated Bouchard arthrosis has to be reconsidered. In vivo and in vitro experiments are necessary to evaluate the potential harms of this combination of therapies. A close clinical and radiological control of treatment outcome with reevaluation of the indication is necessary.

Laser Therapy on Arthritis Induced by Urate Crystals

OBJECTIVE

We aimed to evaluate low-power laser therapy efficacy on fibrinogen (PF) in the plasma of rats with arthritis induced by urate crystals. In addition, anatomopathological (AP) studies were carried out.

BACKGROUND DATA

Raised blood uric acid may form microscopic crystals in the joint. These crystals set up the inflammation called "acute gouty arthritis."

METHODS

Two mg of uric acid were injected in both joints of the lower limbs of rats over 2 days. A group was treated with He-Ne laser (6 mW) on the injected joints during 3 consecutive days. After 96 h of the first injection, animals were sacrificed to determine fibrinogen by spectrophotometry. Sections from the lower limbs were used for AP studies.

RESULTS

A statistically significant increase (p < 0.001) in plasma fibrinogen levels was observed in the group injected with urates, when compared to both control group and the laser-treated group. The AP observed in the untreated group showed an intense fibroblastic proliferation and chronic inflammation. In the group treated with laser no inflammatory reaction was observed.

CONCLUSIONS

Laser therapy has an anti-inflammatory effect in arthropathy induced in rats injected with urates, determined by fibrinogen levels and by histological involution.

Yttrium90 synovectomy in the management of chronic knee arthritis: a single institution experience

Radiation synovectomy (RS) has been used to treat chronically inflamed joints refractory to treatment using conventional agents. In RS, the radioactive isotope is concentrated in the synovial membrane from the injected colloid suspension, where it exerts its activity. However, despite numerous reports confirming its safety and efficacy, this procedure is not widely practised. In the Singleton Hospital NHS Trust, yttrium(90) (Y(90)) RS has been practised since 1990 for refractory synovitis. In this study, we analyse the results of therapy and complications in 38 joints so treated. Doses of 10 mCi were used in the majority of patients. Most responses were apparent by 6 months following the procedure. Altogether, 68% of the treated joints showed satisfactory response at 3 years, with 29% having all symptoms under control beyond 3 years. In three patients, there was evidence of minor pigmentation at the injection site. Two patients had extravasation of the isotope and needle track ulcers, which were recorded as major toxicity. We find Y(90) radiosynovectomy to be safe, quick, and effective in the management of patients with refractory synovitis. The efficacy of RS should be tested in randomised clinical trials involving large numbers of patients.

Analysis of lapine cartilage matrix after radiosynovectomy with holmium-166 ferric hydroxide macroaggregate

OBJECTIVE

To study the short and long term effects of radiosynovectomy on articular cartilage in growing and mature rabbits.

METHODS

The articular cartilage of the distal femurs of rabbits was examined four days, two months, and one year after radiosynovectomy with holmium-166 ferric hydroxide macroaggregate ([(166)Ho]FHMA). Arthritic changes were evaluated from histological sections by conventional and polarised light microscopy, and glycosaminoglycan measurements using safranin O staining, digital densitometry, and uronic acid determination. Proteoglycan synthesis was studied by metabolic [(35)]sulphate labelling followed by autoradiography, and electrophoretic analysis of extracted proteoglycans. Northern analyses were performed to determine the mRNA levels of type II collagen, aggrecan, and Sox9 in cartilage samples.

RESULTS

Radiosynovectomy had no major effect on the histological appearance of articular cartilage in mature rabbits, whereas more fibrillation was seen in [(166)Ho]FHMA radiosynovectomised knee joints of growing rabbits two months after treatment, but not after one year. Radiosynovectomy did not cause changes in the glycosaminoglycan content of cartilage or in the synthesis or chemical structure of proteoglycans. No radiosynovectomy related changes were seen in the mRNA levels of type II collagen, whereas a transient down regulation of aggrecan and Sox9 mRNA levels was seen in young rabbits two months after [(166)Ho]FHMA radiosynovectomy.

CONCLUSIONS

[(166)Ho]FHMA radiosynovectomy caused no obvious chondrocyte damage or osteoarthritic changes in mature rabbits, but in growing rabbits some transient radiation induced effects were seen--for example, mild cartilage fibrillation and down regulation of cartilage-specific genes.

Monarthritis of the ankle as manifestation of a calcaneal metastasis of bronchogenic carcinoma

We report a case of bronchiogenic carcinoma metastasizing to the calcaneus and clinically manifesting itself as a therapy-refractory monarthritis in the right ankle. There is a wide spectrum of possible diagnoses of acute ankle monarthritis including different forms of inflammatory rheumatic diseases, sarcoidosis, osteoarthritis, or septic arthritis. Primary or metastatic malignancies of the hand or foot bones are considered to be rare. Persistent monarthritis as a sole symptom of a calcaneal metastasis has never been reported. This case demonstrates possible difficulties in the early differential diagnosis of acute monarthritis, and will be discussed with respect to the few reports on foot acrometastases.

The effect of radiation synovectomy in patients with persistent arthritis: a prospective study

OBJECTIVE

To investigate and compare the effects of radiation synovectomy of various joints in a rheumatological practice.

METHODS

Consecutive patients referredfor radiation synovectomy to Medical Center Alkmaarfrom 1993 till 1996 were analyzed (n = 138). Patients had to have persistent arthritis despite at least two intra-articular glucocorticoid injections with 20 mg triamcinolone hexacetonide. The knees were treated with 185 MBq Yttrium-90; shoulders, elbows, wrists, hips and talocrural joints received 185 MBq Rhenium-186 and meta-carpophalangeal joints and proximal interphalangeal joints 37 MBq Erbium-169. The radionuclide injection was followed by injection of 20 mg triamcinolone in order to prevent flare-up of synovitis (due to chemical irritation) and needle-track burn. The clinical effect was assessed by evaluating VAS pain (0-10 point scale), functional disability, tenderness and swelling of the treated joint and patient's and physician's global assessments of the effect of therapy (each on a 4-point scale).

RESULTS

The overall success rate for radiation synovectomy one year after treatment was 70% with a significant improvement in the variables VAS pain, functional disability and joint tenderness and swelling, when compared to baseline values (p < 0.000001). Moderate to considerable satisfaction of patients and physicians one year after treatment was found for > 50% of cases. Wrists and shoulders were the joints with highest success rate of treatment, followed by the elbows. Lowest success rates were found for hips and ankles. In RA treatment was effective in 76% of cases whereas patients with OA exhibited a success rate of 50%. In RA all treated joints, except the ankles, exhibited a success rate of > or = 75%. No short-term clinical adverse side effects were noted.

CONCLUSION

Radiation synovectomy seems to be a successful treatment for persistent arthritis when other therapeutic modalities have failed.

Acute arthritis as an unusual complication of malignancy

A 59-year-old man presented with an inability to weight-bear due to an acute, red, hot, swollen knee joint which was subsequently found to be due to a malignant joint effusion consequent to colonic carcinoma. Treatment with radiation therapy relieved his symptoms. A review of the literature reveals that malignant joint effusion is rare and this is only the third reported case secondary to colonic carcinoma.

Systemic radiation therapy with unsealed radionuclides

Systemic unsealed radiation therapy is achieved when a radioactive substance is administered orally or parenterally and that material is concentrated in an organ or site for sufficient time to deliver a therapeutic dose of radiation. The radioactive material usually emits beta particles. In general, there is intense local radiation of the abnormal tissues, and normal organs, which do not trap the radioactive material, are exposed to a small radiation dose. The most frequent treatments involve radioiodine (131)I for hyperthyroidism and differentiated thyroid cancer. Other applications include treatment of painful skeletal metastases, polycythemia vera, malignant cysts, and neuroendocrine tumors. The treatments are usually well tolerated and not associated with long-term effects, such as cancer or infertility.

Radiation synovectomy using 165Dy ferric-hydroxide and oxidative DNA damage in patients with different types of arthritis

Radiation synovectomy is an effective treatment for chronic synovitis refractory to pharmacological treatment in patients with rheumatoid or seronegative arthritis. Concerns persist about possible radiation-induced cytogenetic damage after radiation synovectomy leading to recommendations to use this technique only in the elderly. Micronucleus (MN) frequency in lymphocytes and urinary excretion of 8-hydroxy-2'-deoxyguanosine (8OHdG) as an indicator of cellular oxidative DNA base damage are biomarkers of radiation-induced cytogenetic damage. The course of both biomarkers was studied in patients with different types of chronic synovitis undergoing radiation synovectomy with very short-lived 165Dy-ferric-hydroxide (DFH).

METHODS

Radiation synovectomy of the knee was performed in 13 men and 12 women (mean age, 44+/-15 y) using a mean activity of 9.48+/-1.65 GBq 165Dy-DFH in 27 consecutive treatments. MN frequency in lymphocytes and urinary excretion of 8OHdG, measured by high-performance liquid chromatography, were assessed before and 4 (MN only) and 20 h after radiation synovectomy.

RESULTS

Urinary excretion of 8OHdG in patients (in micromol/mol creatinine; pretreatment mean, 3.1+/-3.4; median, 2.27) was not significantly different from that in healthy volunteers (mean, 2.0+/-1.2; median, 1.87) and not altered by radiation synovectomy (post-treatment mean, 2.5+/-1.5; median, 2.04, NS). An increase in 8OHdG levels after radiation synovectomy of more than 1 SD was found in only 1 patient, who experienced leakage to the lymph nodes but who already had elevated urinary 8OHdG levels before treatment. The frequency of MN/500 binucleated cells (BNCs) was slightly lower in patients (pretreatment mean, 4.3+/-2.6; median, 4.25) than in healthy volunteers (mean, 5.4+/-2.3; median, 5.3) and did not significantly change after therapy, either (4-h post-treatment mean, 3.9+/-2.1, median, 3.8; 20-h post-treatment mean, 4.1+/-2, median 3.8 MN/500 BNC). In 22 of 27 treatments, no leakage to nontarget organs could be monitored, whereas leakage to the local lymph nodes and the liver was detected after 5 treatments.

CONCLUSION

Radiation synovectomy using 165Dy-DFH causes no significant radiation burden to most patients as indicated by the absence of adverse changes in levels of biomarkers of cytogenetic damage and a low incidence of leakage. These data suggest that the risk of malignancy may not be elevated.