Dental bleaching with ozone: effects on color and enamel microhardness.

The aim of this in vitro study was to evaluate the effects of dental bleaching with ozone (O3) on color change and enamel microhardness. Enamel blocks (3 x 3 x 3mm) were randomly distributed for treatments (n=10). Color change (ΔE) and Knoop microhardness of the enamel blocks were evaluated before and after the following treatments: C - deionized water (control); HP - 37.5% hydrogen peroxide (Pola Office+/ SDI); PLA - placebo gel; O3 - ozone; and O2 - oxygen. Four 8-minute applications were used for HP and PLA, and one 19-minute application for O3 and O2.One-way ANOVA revealed that ΔE was not significantly influenced by the treatment (p = 0.112). For the treatments with HP, PLA, O3 andO2, ΔE was greater than 3.3. The paired t test showed significant decrease in microhardness after treatments (p < 0.001) but no significant difference between treatments (ANOVA; p = 0.313). Dental bleaching treatments with O3, HP, O2 and PLA induced enamel color changes that may be clinically discernible, although enamel microhardeness decreased.

O objetivo deste estudo in vitro foi avaliar os efeitos do clareamento dental com ozônio (O3) quanto à alteração de cor e microdureza do esmalte. Blocos de esmalte (3 x 3 x 3mm) foram aleatoriamente distribuídos entre os tratamentos (n=10). Alteração de cor (ΔE) e microdureza Knoop foram avaliados antes e após cada um dos seguintes tratamentos: C ­ água deionizada (controle); PH ­ peróxido de hidrogênio a 37,5% (Pola Office+/ SDI); PLA ­ gel placebo; O3 ­ ozônio; O2 ­ oxigênio. Quatro aplicações de PH e PLA foram realizadas por 8 minutos cada e uma aplicação de O3 e O2 foram realizados por 19 minutos em cada bloco de esmalte. ANOVA a um critério mostrou que os valores de ΔE não foram significativamente influenciados pelo tratamento (p = 0,112). Para os tratamentos com PH, PLA, O3 e O2, o ΔE foi maior que 3,3. O teste t pareado mostrou diminução significativa dos valores de microdureza no final do tratamento quando comparado com o tempo baseline (p < 0,001), mas não houve diferença significativa entre os tratamentos (ANOVA; p = 0,313). O tratamento com O3, PH, O2 e PLA levou a alteração de cor do esmalte clinicamente perceptível, embora tenha sido observada diminuição da microdureza do esmalte com a realização dos tratamentos.

Dental bleaching with ozone: effects on color and enamel microhardness / Clareamento dental com ozônio: efeitos na cor e na microdureza do esmalte

The aim of this in vitro study was to evaluate the effects of dentalbleaching with ozone (O3) on color change and enamelmicrohardness. Enamel blocks (3 x 3 x 3mm) were randomlydistributed for treatments (n=10). Color change (ΔE) and Knoopmicrohardness of the enamel blocks were evaluated before andafter the following treatments: C – deionized water (control); HP– 37.5% hydrogen peroxide (Pola Office+/ SDI); PLA – placebogel; O3– ozone; and O2– oxygen. Four 8-minute applicationswere used for HP and PLA, and one 19-minute application for O3and O2.One-way ANOVA revealed that ΔE was not significantlyinfluenced by the treatment (p = 0.112). For the treatments withHP, PLA, O3 and O2, ΔE was greater than 3.3. The paired t testshowed significant decrease in microhardness after treatments (p< 0.001) but no significant difference between treatments(ANOVA; p = 0.313). Dental bleaching treatments with O3, HP,O2and PLA induced enamel color changes that may be clinicallydiscernible, although enamel microhardeness decreased.

O objetivo deste estudo in vitro foi avaliar os efeitos doclareamento dental com ozônio (O3) quanto à alteração de core microdureza do esmalte. Blocos de esmalte (3 x 3 x 3mm)foram aleatoriamente distribuídos entre os tratamentos(n=10). Alteração de cor (ΔE) e microdureza Knoop foramavaliados antes e após cada um dos seguintes tratamentos: C– água deionizada (controle); PH – peróxido de hidrogênio a37,5% (Pola Office+/ SDI); PLA – gel placebo; O3– ozônio;O2– oxigênio. Quatro aplicações de PH e PLA foramrealizadas por 8 minutos cada e uma aplicação de O3e O2foram realizados por 19 minutos em cada bloco de esmalte.ANOVA a um critério mostrou que os valores de ΔE não foramsignificativamente influenciados pelo tratamento (p = 0,112).Para os tratamentos com PH, PLA, O3 e O2, o ΔE foi maior que3,3. O teste t pareado mostrou diminução significativa dosvalores de microdureza no final do tratamento quandocomparado com o tempo baseline (p < 0,001), mas não houvediferença significativa entre os tratamentos (ANOVA; p =0,313). O tratamento com O3, PH, O2e PLA levou a alteraçãode cor do esmalte clinicamente perceptível, embora tenha sidoobservada diminuição da microdureza do esmalte com arealização dos tratamentos.

Photobiostimulation reduces edema formation induced in mice by Lys-49 phospholipases A2 isolated from Bothrops moojeni venom.

The prominent local myotoxic effects induced by Bothrops snake venom are due, in part, to myotoxins. This effect is not neutralized by antivenom, which is the main therapy for victims of snakebite. Two basic myotoxins named MjTX-I and MjTX-II were isolated from Bothrops moojeni venom. Both myotoxins have a Lys-49 phospholipase A2 structure devoid of enzymatic activity, but are highly myonecrotic and edema-inducing. In this study, we analyzed the effect of a low-level laser (LLL) at 685 nm, an energy density of 2.2 J cm(-2), and the irradiation time of 15 s, and a light emitting diode (LED) at 635 or 945 nm at energy densities of 4 and 3.8 J cm(-2), and irradiation times of 41 and 38 s, respectively, applied 30 min and 3 h after edema formation in mice caused by MjTX-I or MjTX-II. MjTX-I or MjTX-II caused a significant edema formation in envenomed paws. LLL and LED irradiation significantly reduced the edema formation by both myotoxins from 1 up to 6 hours after the injection. Both LLL and LEDs were similar in reducing the edema formation induced by myotoxins. The combined photobiostimulation with antivenom had the same effect in reducing edema as treatment with the LLL or LEDs alone. In conclusion, the results of this study indicate that photobiostimulation could be used in association with antivenom therapy for treatment of local effects of Bothrops species venom.

Analgesic Effect of Light-Emitting Diode (LED) Therapy at Wavelengths of 635 and 945 nm on Bothrops moojeni Venom-Induced Hyperalgesia.

Envenoming induced by Bothrops snakes is characterized by drastic local tissue damage involving hemorrhage, myonecrosis and proeminent inflammatory and hyperalgesic response. The most effective treatment is antivenom therapy, which is ineffective in neutralizing the local response. Herein, it was evaluated the effectiveness of light-emitting diode (LED) at wavelengths of 635 and 945 nm in reducing inflammatory hyperalgesia induced by Bothrops moojeni venom (BmV) in mice, produced by an subplantar injection of BmV (1 µg). Mechanical hyperalgesia and allodynia were assessed by von Frey filaments at 1, 3, 6 and 24 h after venom injection. The site of BmV injection (1.2 cm(2) ) was irradiated by LEDs at 30 min and 3 h after venom inoculation. Both 635 nm (110 mW, fluence of 3.76 J/cm(2) and 41 s of irradiation time) and 945 nm (120 mW, fluence of 3.8 J/cm(2) and 38 s of irradiation time) LED inhibited mechanical allodynia and hyperalgesia of mice alone or in combination with antivenom treatment, even when the symptoms were already present. The effect of phototherapy in reducing local pain induced by BmV should be considered as a novel therapeutic tool for the treatment of local symptoms induced after bothropic snake bites.

Catheters: instrumental advancements in biomedical applications of optical fibers.

This review is focused on the advancements in biomedical engineering regarding the elaboration of new prototypes of optical fiber catheters to be applied in spectroscopic analysis, such as Raman and fluorescence spectroscopy. Our group has contributed to the development of new prototypes with interesting properties, such as side-viewing signal excitation and collection, distal tip with bending control, and Raman scattering minimization from the optical fiber. In addition, several groups have contributed to other new catheter-improving properties of this spectroscopic device. However, a relatively small number of studies has been published in the literature, due to industrial interest in this interdisciplinary and multidisciplinary area. To our knowledge, no review that has focused on the applications of catheters to several modes of spectroscopy has been published. In this work we revised this topic, analyzing the advancements and limitations of the recent biomedical catheters.

Cateter óptico para aplicaçöes espectroscópicas / Optic catheter for spectroscopic applications

Neste trabalho é apresentada a caracterização de cateteres utilizando fibras ópticas para aplicações de espectroscopia in vivo. Estes cateteres apresentam a configuração de seis fibras em torno de uma fibra central de mesmo diâmetro, sendo estas fibras do tipo multimodo com diâmetro de núcleo de 100 mum. A eficiência de coleta de radiação para este tipo de cateter é da ordem de 0,05 por cento, variando em função da distância ao tecido e da distribuição de intensidade de sinal retroespalhado na superfície do mesmo.

ln this work we describe the characterization of fiber optic catheters for in vivo spectroscopy applications. This type of catheters have the geometry of one central fiber sun-ounded by six 100 µm diameter multimode fibers. The collection efficiency of these type of catheter is about 0.05% and it changes with the distance to the tissue surface and the signal intensity distribution on it.

Estudo da eficiência de captaçäo de energia entre cateter momofibra e polifibra / Study about the efficiency of energy uptake between mutifiber and single fiber catheter

Neste trabalho é realizado o estudo comparativo entre o cateter convencional tipo polifibras (6x1), e uma nova configuração do mesmo dispositivo utilizando apenas uma fibra. Os resultados demostram que esta nova configuração apresenta melhor eficiência da coleta de radiação do sinal retroespalhado pela amostra.

This work aims the comparative study between a standard multifiber catheter (6x1), and a new configuration of the same device using only single fiber. The results show that this new configuration has better collection efficiency for the backscattering signal from the sample.