Avalanche-assisted transient optical phenomenon in aggregated toluidine blue dye.

Pulse-modulated CW laser heat deposition modulates the darkness or the transparency of an aggregated medium in the high signal optical regimen. A recently reported work found that transient optical responses of molecular aggregates can be different depending on whether the sample is excited with a laser wavelength tuned within the absorption band of the monomer or within the absorption band of the aggregates. The different transient responses were attributed to different dynamic processes during the laser-induced disassembling of the molecular aggregates and may have implications in the field of organic electronics and optical devices, such as optical logical gates, optical power limiters and all-optical switching. In this paper laser beams with wavelengths of 663 nm and 532 nm were used to produce sudden changes in the thermodynamic equilibrium of the aggregation states of the ortho-toluidine blue dye, which allowed to observe the occurrence of the avalanche - mediated transient phenomenon in the laser-induced disassembling of ortho-toluidine blue (TBO) aggregates. A double exponential model was adjusted to the registered transient data. The obtained values for the fast components of the transient time responses of ortho-toluidine blue dye, for the studied concentrations, ranged from âˆ¼ 6.5 to 9.5 ms at 532 nm, and from âˆ¼ 43 to 48 ms at 663 nm. A single beam experiment was employed to evaluate the performance of the ortho-toluidine blue dye in a beam power-damping device, driven by the simultaneous and cooperative actions of the laser induced disassembling of aggregated dye units and the thermal lensing effect. It was found that the phenomenon of laser-induced dye disassembling of TBO, acting cooperatively with the thermal lensing effect, damps the laser beam power faster than the thermal lensing phenomenon alone. In addition, the results showed that the speed of the laser beam power-damping is dye dependent.

Blood glucose kinetics during concentric and eccentric muscle contractions

Studies comparing the two classes of stimuli (concentric and eccentric) have shown differences in the improvement of cardiovascular, metabolic, and muscle strength gain. This is an experimental, quantitative, and prospective study that aimed to verify the effect of eccentric exercise on glycolytic consumption and kinetics. The blood glucose kinetics of 17 male subjects was evaluated during a treadmill exercise with a 10% declined floor and velocity that required a 60% metabolic activity of VO2max, for 30 minutes. Seventy-two hours later, the same subjects exercised on the treadmill with a 10% inclined floor and 60% VO2max, for 30 minutes. To quantify glucose, blood samples were collected before the exercise, every three minutes along the 30 minutes of physical activity, and five and 10 minutes after finishing the exercise. For the downward slope, there was a homogeneous group behavior for blood glucose dynamics during the exercise, which was characterized by a monotonic decrease of glucose levels until reaching a minimum value at experimental times between 20 and 30 min, followed by a progressive recovery toward initial values. For the acclivity condition, blood glucose dynamics did not follow such a homogeneous behavior. A set of different types of dynamics could be identified. Experimental data showed that the type of dynamics could be predicted, to some extent, by the basal blood glucose level of subjects. The type of floor slope (upward or downward) directly affected glycolytic consumption and kinetics for the individuals analyzed.

Antiedematous Effect Promoted by Occlusion of Legs with Compressive Socks Containing Infrared-Emitting Ceramic Particulates.

Background: Published literature reports significant improvements in pathological conditions, such as pain, blood dyscrasias, and cellulite, after using topical occlusive accessories containing particulate ceramic materials. Objective: In this study, we investigated whether the use of a topical occluding garment made with synthetic fibers embedded with powdered ceramic materials could be beneficial to patients suffering from edema of lower limb extremities. Materials and methods: The cohort comprised 30 volunteers of both genders who were divided into two study groups. The bioceramic (BC) group wore compressive socks made of fabrics with embedded ceramic powder for 8 h a day for 28 days. The placebo group wore compressive socks of the same material without ceramic powder. The efficacy of the treatment was quantified through weekly plethysmographic measurements. In addition, pain relief was evaluated through a visual analog scale (VAS). Results: Data showed a statistically significant reduction in the edema volume for the BC group compared with the placebo group: 78.9 ± 10.7 mL versus 41.3 ± 5.6 mL, p = 0.003. Further, there was also greater pain relief for the BC group when compared with the placebo group, with a pain decrease of 7.0 ± 0.2 U versus 3.3 ± 0.2 U, respectively, on the VAS from 0 to 10 (p = 0.024). Conclusions: The topical occlusive therapy with compressive socks containing infrared-emitting ceramic particulate in its fabrics showed that they were more beneficial than the placebo garment in the treatment of edema of the inferior member extremities as well as in relief of associated pain.

LED phototherapy in full-thickness burns induced by CO2 laser in rats skin.

Many studies have been conducted on the treatment of burns because they are important in morbidity and mortality. These studies are mainly focused on improving care and quality of life of patients. The aim of this study was evaluate the LED phototherapy effects in rats skin full-thickness burns induced by CO2 laser. The animals were divided in NT group that did not received any treatment and LED group that received LED irradiation at 685 nm, 220 mW, and 4.5 J/cm2 during 40 s by burned area. Biopsies were obtained after 7, 14, and 21 days of treatment and submitted to histological and immunohistochemical analysis. The LED phototherapy shows anti-inflammatory effects, improves angiogenesis, and stimulates the migration and proliferation of fibroblasts. The T CD8+ lymphocytes were more common in burned areas compared to T CD4+ lymphocytes since statistically significant differences were observed in the LED group compared to the NT group after 7 days of treatment. These results showed that LED phototherapy performs positive influence in full-thickness burns repair from the healing process modulated by cellular immune response. The obtained results allowed inferring that burns exhibit a characteristic cell immune response and this cannot be extrapolated to other wounds such as incision and wounds induced by punch, among others.

Application of phototherapy for the healing of the navels of neonatal dairy calves.

The present work evaluated the effects of LED light irradiation on the healing of the navels of neonatal dairy calves. Fifty-seven neonatal calves were divided into two groups. Animals had their umbilical stumps immersed in 10% iodine tincture for 60 s, and this process was repeated every 24 h for three consecutive days. The 29 animals in the first group did not receive LED therapy. The 28 animals in the second group received LED light irradiation at 640 nm with 300 mW power, 46.8 J/cm2 energy density, 60 s irradiation time, and 0.385 cm2 spot size. The animals were irradiated at four points (46.8 J/cm2 per point) evenly distributed around the insertion site of the umbilical stump every 24 h for three consecutive days. Irradiation with LED light was applied before the umbilical stumps were immersed in the iodine solution. The time after birth at which the umbilical stump fell off of each calf was noted. The umbilical stumps of all animals fell off by the 25th day of age. After the umbilical stump fell off, the healing of the remnant wound was followed up to the 30th day after birth. The area of the wound was measured on the 15th, 20th, and 25th day after birth using digital photographs and computer-assisted area measurements. A two-tailed unpaired t test was applied to analyze the falling off the umbilical stump, whereas a Kruskal-Wallis one-way ANOVA test with a Dunn's multiple comparison test was used for the wound size evolution. GraphPad Prisma 5.0® and GraphPad StatMate 2.00® were used for the statistical analysis. The results revealed that phototherapy hastened the falling off the umbilical stump, accelerated navel healing, and reduced the mortality rate in newborn calves. Therefore, this study introduced a preventive and adjuvant after birth treatment that proved to be effective in reducing the incidences of omphalitis and newborn mortality.

Analysis of experimental tendinitis in rats treated with laser and platelet-rich plasma therapies by Raman spectroscopy and histometry.

The objective of this controlled experimental study was to analyze the changes in the Achilles tendons of rats with experimentally induced tendinitis after treatment with platelet-rich plasma (PRP) and/or laser therapies by histometry to quantify fibroblasts and by Raman spectroscopy to determine the biochemical concentration of collagen types I and III. Fifty-four male Wistar rats were divided into six treatment groups: control (G1); PRP only (G2); irradiation with 660 nm laser (G3); irradiation with 830 nm laser (G4); PRP plus 660 nm laser irradiation (G5); and PRP plus 830 nm laser irradiation (G6). Injuries (partial tenotomy) were inflicted in the middle third of the Achilles tendon, with PRP added prior to suture in the appropriate experimental groups. A diode laser (model Laser Flash® III, DMC Equipamentos Ltda, São Carlos, SP, Brazil) that can be operated in two wavelengths 660 and 830 nm was used for irradiation treatments. The irradiation protocol was energy density of 70 J/cm², 20 s irradiation time, and 0.028 cm² spot area, per point in three points in the injured. The histometry was made in micrographical images of the H&E stained sections and evaluated by ImageJ (version 1.46r)®. Raman spectra were collected using a dispersive spectrometer at 830 nm excitation, 200 mW power, and 10 s integration time (P-1 Raman system, Lambda Solutions, Inc. MA, USA). The relative amount of type I collagen was significantly greater in the PRP plus 830 nm laser irradiation group (468 ± 188) than in the control (147 ± 137), 630 nm laser only (191 ± 117), and 830 nm laser only (196 ± 106) groups (p < 0.01), while the quantity of type III collagen was significantly greater in the PRP-only group compared to both irradiated groups without PRP (p < 0.05). Treatment with PRP combined with irradiation at 830 nm resulted in a larger number of fibroblasts and increased concentration of type I collagen, thus accelerating the healing of the injured tendon.

Experimental full-thickness burns induced by CO2 laser.

Many studies have been conducted on the treatment of burns because they are important in morbidity and mortality. These studies are mainly focused on improving care and quality of life of patients. The aim of this study is the induction of standardized full-thickness burns of the skin of rats using the CO2 laser. The results show that non-contact technique using the CO2 laser is effective to induce such standardization of burning and is an important step in determining the efficiency of different therapies used in treating burns.

Thermo-optical characterization of cadmium selenide/zinc sulfide (CdSe/ZnS) quantum dots embedded in biocompatible materials.

Cadmium selenide/zinc sulfide (CdSe/ZnS) core-shell quantum dots (QDs) embedded in biocompatible materials were thermally and optically characterized with a thermal lens (TL) technique. Transient TL measurements were performed with a mode-mismatched, dual-beam (excitation and probe) configuration. A thermo-optical study of the CdSe/ZnS QDs was performed for different core diameters (3.5, 4.0, 5.2, and 6.6 nm) in aqueous solution and synthetic saliva, and three different core diameters (2.4, 2.9, and 4.1 nm) embedded in restorative dental resin (0.025% by mass). The thermal diffusivity results are characteristic of the biocompatible matrices. The radiative quantum efficiencies for aqueous solution and biofluid materials are dependent on the core size of the CdSe/ZnS core-shell QDs. The results obtained from the fluorescence spectral measurements for the biocompatible materials support the TL results.

Photodynamic inactivation of yeast and bacteria by extracts of Alternanthera brasiliana.

This study was undertaken to evaluate the effect of Alternathera brasiliana (Amaranthaceae) extracts as photosensitizing agents in photodynamic antimicrobial therapies (PACT) against Staphylococcus aureus, Staphylococcus epidermidis and Candida dubliniensis. The crude hexane and ethanol extracts were obtained from A. brasiliana whole plant and showed absortion from 650 to 700 nm. Also, singlet molecular oxygen (1O2) production (type II photosensitization reaction) was examined, and the results show that 1,3-diphenylisobenzofuran photodegradation was greatly enhanced in the presence of the A. brasiliana extracts. One plate in each assay was irradiated while the other was not irradiated, the number of colony-forming units per milliliter (CFU/mL) was obtained, and data analyzed by the Tukey test. The chemical composition of the extracts was determined by chromatographic and spectrometric techniques; steroids, triterpenes, and flavonoids were identified. Laser irradiation alone at 685 nm using diode laser, output power of 35 mW, and energy of 28 J/cm2, or non-irradiated crude extracts in sub-inhibitory concentration did not reduce the number of CFU/mL significantly, whereas irradiated hexane and ethanol extracts, in sub-inhibitory concentrations, inhibited the growth of these microorganisms. The photoactivation of hexane and ethanol extracts of A. brasiliana, in sub-inhibitory concentrations, using red laser radiation at 685 nm had an antimicrobial effect.

Reductions in body measurements promoted by a garment containing ceramic nanoparticles: a 4-month follow-up study.

BACKGROUND: Published literature reports significant improvements in pathological conditions, such as pain, blood dyscrasias, and cellulite, after using topical occlusive accessories containing particulate ceramic materials. Recent work reported a reduction in body measurements after 30 days of daily use of high-waist undershorts made of synthetic fabrics with embedded ceramic particles. OBJECTIVES: In this study, we investigated whether the use of a garment made with synthetic fibers embedded with powdered ceramic could lead to reductions in body measurements at a longer time span (120 day). METHODS: Thirty-two female volunteers wore clothing containing ceramic powder for at least 8 h a day for 120 days. The efficacy of the treatment was evaluated through anthropometric measurements taken before treatment and after 30, 60, and 120 days of treatment. RESULTS: The experimental data showed a more pronounced reduction in body measurements at the beginning of treatment with a trend of stabilization in measured body circumferences during the final 60 days of the experimental period. CONCLUSIONS: The experimental data showed that the occlusive treatment with a garment composed of ceramic particles promoted reductions in body measurements during a 120-day experimental period.

Influence of coffee and red wine on tooth color during and after bleaching.

OBJECTIVE: The aim of this study was to evaluate the influence of coffee and red wine staining on tooth color during and after bleaching. MATERIALS AND METHODS: Blocks obtained from human molars were divided into 11 groups (n = 5) in accordance with the bleaching treatment-peroxide carbamide 10%, 15% or 20%-and in accordance with the stain therapy-coffee, wine or without staining (control). Color change analysis was performed by photo-reflectance using a spectrophotometer, during (3-times/week) and after (7, 15 and 30 days) the bleaching treatment. During the experiment, the samples were stored in artificial saliva. The results were submitted to statistical analysis with the Dunnet and Tukey tests (p < 0.05). RESULTS: The concentrations of carbamide peroxide (10%, 15% and 20%) did not differ significantly from the control group during bleaching (up to the 22nd day), with (Tukey, p > 0.05) or without storage in pigment solution. After the bleaching, there were statistically significant differences between the groups treated with coffee (30th day) and wine (7th and 30th days) relative to the control, which was treated with whitening agents. CONCLUSION: During bleaching, remineralization of the enamel with artificial saliva and the subsequent bleaching session were effective in preventing enamel staining. After the whitening procedures, both stain therapies-coffee and wine-caused enamel color changes; however, the wine led to greater staining than did coffee.

Low-level laser therapy ameliorates CCl4-induced liver cirrhosis in rats.

This study investigated the effects of low-level laser therapy (LLLT) in the liver function, structure and inflammation in a experimental model of carbon tetrachloride (CCl(4))-induced liver cirrhosis. Wistar rats were divided into Control, LLLT, CCl(4) and CCl(4) +LLLT groups. CCl(4) groups received CCl(4) (0.4 g kg(-1); i.p.), three times a week, for 12 weeks. A 830 nm LLLT was performed with a continuous wave, 35 mW, 2.5 J cm(-2) per point, applied to four points of the liver (right and left upper and lower extremities, in the four lobes of the liver) for 2 weeks. Liver structure and inflammation (cirrhotic areas, collagen deposition, inflammation, density of Kupffer and hepatic stellate cells) and function (aspartate aminotransferase, alkaline phosphatase, gamma glutamyltransferase, lactate dehydrogenase, total proteins and globulins) were evaluated. LLLT significantly reduced CCl(4)-increased aspartate aminotransferase (P < 0.001), alkaline phosphatase (P < 0.001), gamma-glutamyl transferase (P < 0.001) and lactate dehydrogenase (P < 0.01) activity, as well as total proteins (P < 0.05) and globulins (P < 0.01). LLLT also reduced the number of cirrhotic areas, the collagen accumulation and the hepatic inflammatory infiltrate. Of note, LLLT reduced CCl(4)-increased number of Kupffer cells (P < 0.05) and hepatic stellate cells (P < 0.05). We conclude that LLLT presents beneficial effects on liver function and structure in an experimental model of CCl(4)-induced cirrhosis.

Evaluation of ultrasound and light sources as bleaching catalysts - an in vitro study.

PURPOSE: To evaluate the efficacy of tooth bleaching with high concentration agents, varying the catalyst sources and exposure times. MATERIALS AND METHODS: Stained human third molar fragments were randomized and placed into 8 groups (n = 5). G1: Whiteness HP Maxx (FGM, Joinville, SC, Brazil) 35% (HP)/5 min on enamel surface without external catalyst source; G2: HP/15 min without external catalyst association; G3: HP/5 min with Quartz Tungstein Halogen (QTH: Optilux 501C, Demetron/Kerr, Danbury, CT, USA) as a catalyst; G4: HP/15 min with QTH as a catalyst; G5: HP/5 min with LED/laser as a catalyst; G6: HP/15 min with LED/ laser as a catalyst; G7: HP/5 min with ultrasound as a catalyst; G8: HP/15 min with ultrasound as a catalyst. The efficacy of bleaching was measured using a spectrophotometer (initial fotoreflectance analysis, after artificial staining with black tea, and after each of the bleaching sessions). Three bleaching sessions were performed. Data were submitted to Analysis of Variance and Tukey-Kramer tests (P < 0.05). RESULTS: No significant differences were found between the catalyst sources as related to the factor of exposure time and within each evaluation time. For the 15 min exposure, the best result was achieved in the second bleaching session, except for the LED/laser group. For the 5 min exposure, the best result was achieved in the third session, except for ultrasound. The 15 min of exposure time showed higher reflectance than 5 min for LED/laser and ultrasound in all bleaching sessions and for halogen in the second bleaching session. CONCLUSION: Light sources did not increase the catalytic efficiency of bleaching, and allowing a longer time for gel exposure on the enamel achieves faster results.

Photodynamic inactivation of Staphylococcus aureus and Escherichia coli biofilms by malachite green and phenothiazine dyes: an in vitro study.

OBJECTIVES: The organization of biofilms in the oral cavity gives them added resistance to antimicrobial agents. The action of phenothiazinic photosensitizers on oral biofilms has already been reported. However, the action of the malachite green photosensitizer upon biofilm-organized microorganisms has not been described. The objective of the present work was to compare the action of malachite green with the phenothiazinic photosensitizers (methylene blue and toluidine blue) on Staphylococcus aureus and Escherichia coli biofilms. METHODS: The biofilms were grown on sample pieces of acrylic resin and subjected to photodynamic therapy using a 660-nm diode laser and photosensitizer concentrations ranging from 37.5 to 3000 µM. After photodynamic therapy, cells from the biofilms were dispersed in a homogenizer and cultured in Brain Heart Infusion broth for quantification of colony-forming units per experimental protocol. For each tested microorganism, two control groups were maintained: one exposed to the laser radiation without the photosensitizer (L+PS-) and other treated with the photosensitizer without exposure to the red laser light (L-PS+). The results were subjected to descriptive statistical analysis. RESULTS: The best results for S. aureus and E. coli biofilms were obtained with photosensitizer concentrations of approximately 300 µM methylene blue, with microbial reductions of 0.8-1.0 log(10); 150 µM toluidine blue, with microbial reductions of 0.9-1.0 log(10); and 3000 µM malachite green, with microbial reductions of 1.6-4.0 log(10). CONCLUSION: Greater microbial reduction was achieved with the malachite green photosensitizer when used at higher concentrations than those employed for the phenothiazinic dyes.

Aloe vera extract reduces both growth and germ tube formation by Candida albicans.

Due to the increased number of immunocompromised patients, the infections associated with the pathogen of the genus Candida have significantly increased in recent years. To grow, Candida albicans may form a germ tube extension from the cells, which is essential for virulence. In this work, we studied the effect of crude glycolic extract of Aloe vera fresh leaves (20% w/v) on growth and germ tube formation by C. albicans. The C. albicans growth was determined in the presence of different concentrations of A. vera extracts in Sabouraud dextrose broth medium. In the presence of A. vera extract (10% v/v), the pronounced inhibition in the C. albicans growth (90-100%) was observed. This inhibition occurred parallel to the decrease in the germ tube formation induced by goat serum. Our results demonstrated that A. vera fresh leaves plant extract can inhibit both the growth and the germ tube formation by C. albicans. Our results suggest the possibility that A. vera extract may be used as a promising novel antifungal treatment.

Effect of incoherent LED radiation on third-degree burning wounds in rats.

The main physiological characteristics in a burn process are the increase of the capillary permeability and the occurrence of edema and exudation. Light-emitting diode (LED) has been proposed as treatment of burning. This study investigated the effects of LED on the repair process of rat skin submitted to a third-degree burning. The lesions were produced on the dorsal surface of male Wistar rats. Animals were divided into 4 groups (n = 6) as follows: L1 and L2 groups as LED-treated burned rats, and received LED therapy along 7 and 15 days with 48 hours intervals, respectively; C1 and C2 groups as control, non-treated burned rats. A red LED (640 nm, 30 mW) operating with a fluence of 4 J/cm(2) was used. The wound area was measured daily after irradiation. Animals were euthanized at the 8th and 16th days after burning, and the wound fragment was submitted to histology. The inflammatory cells as well as the damaged area at the 8th day after burns were significantly lower for the LED-treated group when compared to control. Furthermore, the LED phototherapy effect on cellular migration was even more pronounced at the 16th day. Our results indicated that the treatment with a LED system was clearly effective in reducing the number of inflammatory cells and improving the healing process in an experimental model of third-degree burnings.

Reduction in body measurements after use of a garment made with synthetic fibers embedded with ceramic nanoparticles.

BACKGROUND: Therapeutic effects have been attributed to far-infrared (FIR) radiation emitted from different types of sources. One class of such infrared emitters consists of ceramics in a powdered form, which allows for its incorporation into creams and fabrics. Such ceramic materials emit in the FIR when subjected to body temperature. Published literature reports significant improvement in both pathological conditions, such as pain and blood dyscrasias, and cellulite upon use of accessories containing ceramic emitters. OBJECTIVES: In this study, we investigated whether the use of a garment made with synthetic fibers embedded with powdered ceramic led to a reduction in body measurements. METHODS: The study population comprised 42 women divided into two groups: active and placebo. The volunteers used clothing either impregnated or not impregnated with ceramic powder for at least 8 h/day for 30 days. RESULTS: The experimental data showed a reduction in body measurements, which may be a consequence of an increment in microcirculation and peripheral blood flow, and these changes might promote improved general health. CONCLUSIONS: Objective indicators were identified which showed that the reported ceramic accessories actually were capable of biological modulation.

Optical characterization in annatto and commercial colorific.

Nowadays, the synthetic dyes (as erythrosine, ponceau and tartrazina) and natural colourants (as annatto, paprika, curcuma and anthocyanin) are indispensable in the food, pharmaceutical and cosmetics applications. However, the use of natural colourant has been considered safer for human consumption then synthetic dye. For practical applications of the coloring, optical properties are important for the understanding of the characteristics of them. In this work, we presented the absorption and fluorescence spectroscopic characterizations of annatto extracts obtained from the seeds of the tropical shrub Bixa orellana L. solutions and commercial colourant. The measurements were performed in annatto extracts with acetone and chloroform in different concentrations range (3.5-52.5) µg/mL. The main carotenoids detected in annatto seeds is bixin. The numerical calculus of the absorbance spectra for cis- and trans-bixin conformation is presented. In addition, for commercial colourant, the measurements were performed for six different brands and five lots each one. Modifications in the shape of the colorific fluorescence spectra were observed and it can be an indicative of differences in the industrial methods applied for obtaining annatto pigments powders and/or the possibility of the presence of other impurities added in the commercial powders.

Influence of chemical or physical catalysts on high concentration bleaching agents.

OBJECTIVES: The aim of this in vitro study was to evaluate the bleaching efficacy of high concentration bleaching agents activated by chemical or physical catalysts. MATERIALS AND METHODS: This study was divided into two parts. Part 1 evaluated the efficacy of tooth whitening after treatment with 35% hydrogen peroxide (Whiteness HP Maxx) that was activated by different light-curing units: halogen lamp (conventional and bleach mode) (Optilux 501C, Demetron/Kerr), LED first generation (Ultrablue IV, DMC), LED/diode laser (Ultrablue IV, DMC), LED second generation (Bluephase 16i, Ivoclar Vivadent), and no light source (control group). Part 2 provided an analysis of the effect of chemical and physical catalysts on high concentration bleaching agents: 35% hydrogen peroxide (Whiteness HP Maxx) + 20% sodium hydroxide; 35% hydrogen peroxide + 7% sodium bicarbonate; 38% hydrogen peroxide (Opalescence Xtra Boost); 35% hydrogen peroxide + halogen lamp; 35% hydrogen peroxide + 20% sodium hydroxide + halogen lamp; 35% hydrogen peroxide + 7% sodium bicarbonate + halogen lamp; 38% hydrogen peroxide + halogen lamp; and 35% hydrogen peroxide. Blocks obtained from human molars were randomly divided into groups (n = 5) in accordance with bleaching treatments. The efficacy of bleaching was measured using a spectrophotometer. Three bleaching sessions were performed. The results were submitted to ANOVA followed by the Tukey test (5%). RESULTS: For both parts of the study, activated vs. non-activated bleaching did not differ significantly for all sessions tested. CONCLUSION: Activating systems did not improve the whitening effectiveness of high concentration bleaching agents.

Comparative study of the topical application of Aloe vera gel, therapeutic ultrasound and phonophoresis on the tissue repair in collagenase-induced rat tendinitis.

The aim of our study was to compare topical use of Aloe vera gel, pulsed mode ultrasound (US) and Aloe vera phonophoresis on rat paw with collagenase-induced tendinitis. Edema size, tensile tendon strength, tendon elasticity, number of inflammatory cells and tissue histology were studied at 7 and 14 days after tendinitis induction. Pulse mode US parameters were: 1 MHz frequency, 100 Hz repetition rate, 10% duty cycle, and 0.5 W/cm(2) intensity, applied for 2 min each session. A 0.5 mL of Aloe vera gel at 2% concentration was applied for 2 min per session, topically and by phonophoresis. Topical application of Aloe vera gel did not show any statistically significant improvement in the inflammatory process, whereas phonophoresis enhanced the gel action reducing edema and number of inflammatory cells, promoting the rearrangement of collagen fibers and promoting also the recovery of the tensile strength and elasticity of the inflamed tendon to recover their normal pre-injury status. Results seem to indicate that Aloe vera phonophoresis is a promising technique for tendinitis treatment, without the adverse effect provoked by systemic anti-inflammatory drugs.