Effect of low-level laser therapy on the healing process after tooth replantation: a histomorphometrical and immunohistochemical analysis

Success of tooth replantation is limited because part of the replanted tooth is lost because of progressive root resorption. This study used histomorphometry and immunohistochemistry to evaluate the effect of low-level laser therapy (LLLT) on the healing process of rat teeth replanted after different extra-oral periods, simulating immediate and delayed replantation. Sixty Wistar rats (Rattus norvegicus albinus) had their maxillary right incisors extracted and randomly assigned to six groups (n = 10): C4, C30 and C45, in which the teeth were replanted 4 min (immediate), 30 min (delayed) and 45 min (delayed) after extraction, respectively, and L4, L30 and L45, in which the teeth were replanted after the same extra-alveolar times, but the root surfaces and the alveolar wounds were irradiated with a gallium-aluminum-arsenate (GaAlAs) diode laser before replantation. The animals were sacrificed after 60 days. The anatomic pieces containing the replanted teeth were obtained and processed for either histomorphometrical analysis under optical microscopy or immunohistochemical expression of receptor activator of nuclear factor Kappa-B (RANK), and its ligand (RANKL), osteoprotegerin (OPG) and tartrate-resistant acid phosphatase (TRAP) proteins. Areas of external replacement and inflammatory root resorption were observed in all groups, without statistically significant differences (P > 0.05). Ankylosis was more frequent in L30 than in C30 (P < 0.05). RANKL immunostaining predominated over RANK and OPG immunostaining in both groups with immediate tooth replantation (P < 0.05). For the 45-min extra-alveolar time, however, there was greater evidence of RANK immunostaining compared to RANKL for both control and laser-treated groups (P < 0.05). Positive TRAP immunostaining predominated in L4 and L30 (P < 0.05). In conclusion, under the tested conditions, the treatment of the root surface and the alveolar wound with LLLT did not improve the healing process after immediate and delayed tooth replantation in rats.

Low-Fluoride Acidic Dentifrice: A Randomized Clinical Trial in a Fluoridated Area

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The Efficacy of Laser Fluorescence to Detect in Vitro Demineralization and Remineralization of Smooth Enamel Surfaces

Objective: The purpose of this study was to evaluate the efficacy of the laser fluorescence (LF) device in detecting in vitro demineralization and remineralization of smooth surface caries-like lesions. Background Data: The early detection of smooth surface caries-like lesions is important to provide proper management of carious lesions, and allows monitoring of them over time. Also, some authors suggest that LF could be useful in monitoring the caries pathological process. Materials and Methods: Seventy-eight blocks of bovine teeth were obtained, and then submitted to artificial caries lesion induction and to a pH-cycling process. Superficial microhardness (SMH) and laser fluorescence analysis were performed at baseline, after induction of caries-like lesions, and after the pH-cycling regimen to promote remineralization. Results: Friedman's and multiple comparison tests were performed for all variables. SMH analysis showed significant differences (p < 0.05) between baseline (286.77 +/- 1.49 Vickers hardness number [VHN] units), before (38.48 +/- 0.85 VHN), and after remineralization (131.93 +/- 2.63 VHN). Baseline values for LF were extremely low (2.71 +/- 0.05), and a statistically significant difference was observed only after remineralization (3.61 +/- 0.08), as demonstrated by the increase in LF values. Conclusion: The LF device did not show efficacy for monitoring in vitro demineralization and remineralization of smooth enamel surfaces.

Effects of Er,Cr:YSGG Laser Irradiation on Root Surfaces for Adhesion of Blood Components and Morphology

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Clinical Efficiency of Low-Level Diode Laser in Reducing Dentin Hypersensitivity

Dentin hipersensitivity (DH) is a relatively common clinical condition, especially in periodontal patients after treatment. In this study it was evaluated 28 teeth who presented dentin hypersensitivity. The teeth were subjected to clinical and radiographic exams and were divided into groups following the treatment and the time of examination after application proposed: GI: PO 3% (Potassium Oxalate-group control)/Baseline; GII: PO 3%/3 days after first session; GIII: PO 3%/6 days; GIV: PO 3%/30 days; GV: PO 3%/60 days; GVI: PO 3%/90 days; GVII: Laser (Low-level diode laser with 110 mW/cm(2))/Baseline; GVIII: Laser/7 days after first session; GIX: Laser/14 days; GX: Laser/30 days; GXI: Laser/60 days; and GXII: Laser/90 days. The groups I-VI, the teeth were subjected to 3 applications (GI-GIII) of desensitizing agent at regular intervals of seven days. The Groups VII-XI, each tooth was subjected to three applications (GVII GIX) in three different points (mesial, meddle and distal surfaces) with an interval of 72 h. The time of application in each point was of 33 s and the patients from both groups were followed up to 90 days. The nonparametric test Friedman (alpha = 0.05) was applied and the test of Mann Whitney (alpha = 0.05) was used to compare the time of examination between groups. The application of Laser was effective 6 days after first session and to PO was 30 days. It was observed that both treatments were effective for the reduction of dentin hypersensitivity, however the laser presented better effectiveness.

Occlusal caries prevention in high and low risk schoolchildren. A clinical trial

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Diet compounds, glycemic index and obesity-related cardiac effects

Background: Diet compounds may influence obesity-related cardiac oxidative stress and metabolic sifting. Carbohydrate-rich diet may be disadvantageous from fat-rich diet to cardiac tissue and glycemic index rather than lipid profile may predict the obesity-related cardiac effects.Materials and methods: Male Wistar rats were divided into three groups (n=8/group): (C) receiving standard chow (3.0 kcal/g); (CRD) receiving carbohydrate-rich diet (4.0 kcal/g), and (FRD) receiving fat-rich diet (4.0 kcal/g). Rats were sacrificed after the oral glucose tolerance test (OGTT) at 60 days of dietary treatments. Lipid profile and oxidative stress parameters were determined in serum. Myocardial samples were used to determine oxidative stress, metabolic enzymes, glycogen and triacylglycerol.Results: FRD rats showed higher final body weight and body mass index than CRD and C. Serum cholesterol and low-density lipoprotein were higher in FRD than in CRD, while triacylglycerol and oxidized low-density lipoprotein cholesterol were higher in CRD than in FRD. CRD rats had the highest myocardial lipid hydroperoxide and diminished superoxide dismutase and catalase activities. Myocardial glycogen was lower and triacylglycerol was higher in CRD than in C and FRD rats. Although FRD rats had depressed myocardial-reducing power, no significant changes were observed in myocardial energy metabolism. Myocardial beta-hydroxyacyl coenzyme-A dehydrogenase and citrate synthase, as well as the enhanced lactate debydrogenase/citrate synthase ratio indicated that fatty acid degradation was decreased in CRD rats. Glycemic index was positively correlated with obesity-related cardiac effects.Conclusions: Isoenergetic carbohydrate-rich and fat-rich diets induced different degree of obesity and differently affected lipid profile. Carbohydrate-rich diet was deleterious relative to fat-rich diet in the heart enhancing lipoperoxidation and shifting the metabolic pathway for energy production. Glycemic index rather than dyslipidemic profile may predict the obesity effects on cardiac tissue. (C) 2007 Elsevier B.V. All rights reserved.

Early Changes Induced by Short-Term Low-Dose Cadmium Exposure in Rat Ventral and Dorsolateral Prostates

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Biological aspects of Schizodon nasutus Kner, 1858 (Characiformes, Anostomidae) in the low Sorocaba river basin, São Paulo state, Brazil

Four biological aspects of Schizodon nasutus in the low Sorocaba river basin, São Paulo, Brazil were analysed. These were accomplished during the year seasons. The fish diet and the feeding activity were investigated by studying the repletion index, which showed no significant differences between seasons. The food items analysed by frequency of occurrence and dominance showed a predominance of vegetable items in the diet. The reproduction, analysed by using the gonadosomatic index, indicated that the reproductive period occurs during the summer period when temperatures are higher and rainfalls are more intense. The amount of accumulated fat and condition factor varied according to reproduction, especially for females.

Regular and chaotic interactions of two BPS dyons at low energy

We identify and analyze quasiperiodic and chaotic motion patterns in the time evolution of a classical, non-Abelian Bogomol'nyi-Prasad-Sommerfield (BPS) dyon pair at low energies. This system is amenable to the geodesic approximation which restricts the underlying SU(2) Yang-Mills-Higgs dynamics to an eight-dimensional phase space. We numerically calculate a representative set of long-time solutions to the corresponding Hamilton equations and analyze quasiperiodic and chaotic phase space regions by means of Poincare surfaces of section, high-resolution power spectra and Lyapunov exponents. Our results provide clear evidence for both quasiperiodic and chaotic behavior and characterize it quantitatively. Indications for intermittency are also discussed.

Effect of high and low molecular weight glutenin subunits, and subunits of gliadin on physicochemical parameters of different wheat genotypes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Experimental visceral leishmaniasis in high and low antibody - producer mice (selection IV-A)

A leishmaniose é uma infecção parasitária cuja imunidade protetora envolve a ativação de macrófagos. Neste trabalho avaliamos a susceptibilidade de camundongos H e L (bons e maus produtores de anticorpos, respectivamente) da seleção IV-A, à infecção com o protozoário L. donovani. Camundongos H infectados com 10(7) amastigotas por via intravenosa foram mais suscetíveis, apresentando maior carga parasitária tanto no fígado quanto no baço. Após 60 dias de infecção ambas as linhagens apresentaram um aumento no índice esplênico. Esta esplenomegalia foi conseqüência, pelo menos parcialmente, de um aumento no número de células esplênicas. Os resultados indicam que a seleção IV-A é susceptível à infecção com L. donovani e que dentro desta seleção a linhagem H apresenta maior suscetibilidade do que a linhagem L.

Low optical loss planar waveguides prepared in an organic-inorganic hybrid system

HfO2-(3-glycidoxipropil)trimethoxisilane (GPTS) planar waveguides were prepared by a sol-gel route. A stable sol of Hafnia nanocrystals was prepared and characterized by photon correlation spectroscopy and high resolution transmission electron microscopy. The suspension was incorporated in GPTS host and the resulting sol was deposited on borosilicate substrates by the spin coating technique. Optical properties such as refractive index, thickness, number of propagating modes, and attenuation coefficient were measured at 632.8, 543.5, and 1550 nm by the prism coupling technique as a function of the HfO2 content. (C) 2000 American Institute of Physics. [S0003-6951(00)03348-9].

Antimony orthophosphate glasses with large nonlinear refractive indices, low two-photon absorption coefficients, and ultrafast response

Antimony glasses based on the composition Sb2O3-SbPO4 were prepared and characterized. The samples present high refractive index, good transmission from 380 to 2000 nm, and high thermal stability. The nonlinear refractive index, n(2), of the samples was studied using the optical Kerr shutter technique at 800 nm. The third-order correlation signals between pump and probe pulses indicate ultrafast response (<100 fs) for all compositions. Enhancement of n(2) was observed by adding lead oxide to the Sb2O3-SbPO4 composition. Large values of n(2)approximate to10(-14) cm(2)/W and negligible two-photon absorption coefficients (smaller than 0.01 cm/GW) were determined for all samples. The glass compositions studied present appropriate figure-of-merit for all-optical switching applications. (C) 2005 American Institute of Physics.

Changes of physical properties of glass surfaces exposed to KNO3 vapors

Modifications of glass surfaces were studied after exposure of samples to an atmosphere resulting from the decomposition of molten KNO3. The diffusion coefficient of K+ ions migrating into the surfaces of float glass and synthesized glasses doped with up to 5 wt% SnO2 was calculated by the Boltzmann-Matano technique. The Vickers hardness and the refractive index increase with exposure time. Infrared spectra show that the migration of K+ is responsible for an increase in the number of non-bridging oxygens in the exposed samples. The spectra of the synthesized glasses present evidences that their surfaces undergo crystallization during the exposure. All results lead to the conclusion that the presence of tin in the glasses hinders the diffusion of K+ ions, thus affecting the Vickers hardness, the refractive index and the infrared spectra. It is shown that the exposure method can be used as an alternative process to promote the K+ migration into glass surfaces. (c) 2006 Elsevier B.V. All rights reserved.