Evaluation of colostral immunity in swine with commercial anti-leptospira polyvalent whole-bacteria vaccine

The intensity and duration of passive immunity against swine leptospirosis were investigated by the microscopic agglutination test and in vitro leptospira growth inhibition. Twenty-one females at first parturition were divided into three groups: Group A (n = 08): received two doses with 30 days interval of the commercial anti-leptospira bacterin A. Group B (n = 06) received two doses with 30 days interval of the commercial anti-leptospira bacterin B and Group C (n = 07) was the control. In all groups the colostrums were collected. Blood collection of piglets was performed in four different ages. Agglutinin antibodies were equally detected in sera and colostrums for serovars Canicola, Grippotyphosa, Copenhageni, Icterohaemorrhagiae and Pomona (Group A) and Canicola, Copenhageni, Icterohaemorrhagiae, Pomona and Hardjo (Group 13). Mean neutralizing antibodies titers were low. Passive immunity was low duration. (C) 2007 Elsevier Ltd. All rights reserved.

Evaluation of the Possibility of Removing Staining by Repolishing Composite Resins Submitted to Artificial Aging

This in vitro research verified the possibility of eliminating staining caused by coffee and red wine in five composite resins, after being submitted to thermal cycling. Thirty-six specimens were prepared and immersed in water at 37 degrees C for 24 hours. After polishing, specimen color was measured in a spectrophotometer Cintra 10 UV (Visible Spectrometer, GBC, Braeside, VIC, Australia). All specimens were submitted to thermal cycling at temperatures of 5 and 55 degrees C with a dwell time of 1 minute, for 1,000 cycles in a 75% ethanol/water solution. After thermal cycling, the specimens were immersed in water at 37 degrees C until 7 days had elapsed from the time the specimens were prepared. All specimens were then taken to the spectrophotometer for color measurement. The specimens were divided into three groups (N = 12): distilled water (control), coffee, and red wine. For the staining process to occur on only one surface, all the sides, except one, of the surfaces were isolated with white wax. The specimens were immersed in one of the solutions at 37 degrees C for 14 days. The specimens were dried and taken to the spectrophotometer for color measurement. After this, the specimens were submitted to 20 mu m wear three times, and the color was measured after each one of the wear procedures. Calculation of the color difference was made using CIEDE2000 formula. According to the methodology used in this research, it was concluded that the staining caused by coffee and red wine was superficial and one wear of 20 mu m was sufficient to remove the discoloration.

In vitro evaluation of erbium, chromium:yttrium-scandium-gallium-garnet laser-treated enamel demineralization

This study evaluated the effect of different parameters of erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser irradiation on enamel mineral loss in a simulated caries model. Forty-five enamel samples obtained from third molar teeth (3 mmx 3 mm) were randomly divided into five groups (n = 9): G1-Er,Cr:YSGG laser at 0.25 W, 20 Hz, 2.8 J/cm(2); G2-Er,Cr:YSGG laser at 0.50 W, 20 Hz, 5.7 J/cm(2); G3-Er,Cr:YSGG laser at 0.75 W, 20 Hz, 8.5 J/cm(2); G4-sodium fluoride (NaF) dentifrice (positive control); G5-no treatment (negative control). After irradiation, the samples were submitted to 2 weeks of pH cycling. After the acid challenge, the samples were assessed by cross-sectional microhardness at different depths from the enamel surface. Analysis of variance (ANOVA) and Student-Newman-Keuls tests were performed (alpha = 5%). The percentage of lesion inhibition for each group was: G1 37%; G2 38%; G3 64%, and G4 50.5%. Regarding the relative mineral loss values (micrometers x volume percent), groups G1 (1,392 +/- 522) and G2 (1,292 +/- 657) did not differ significantly from each other, but both had higher values than group G3 (753 +/- 287); the groups irradiated with Er,Cr:YSGG laser did not differ from group G4. Although the findings of the study revealed that Er,Cr:YSGG laser irradiation at 8.5 J/cm(2) can be an alternative for the enhancement of the enamel`s resistance to acid, lower energy densities also produced a cariostatic potential comparable to the use of fluoride dentifrice.

Comparison of different irrigants on calcium hydroxide medication removal: microscopic cleanliness evaluation

Calcium hydroxide dressing residuals can compromise endodontic sealing. This study evaluated the cleaning efficacy of different endodontic irrigants in removing calcium hydroxide by SEM image analysis. Fifty-four single-rooted mandibular premolars were instrumented to a master apical file #60 and dressed with calcium hydroxide. After 36 hours, the teeth were reopened and Ca(OH)(2) medication was removed by 5 different experimental groups: 0.5% NaOCl (G1), EDTA-C (G2), citric acid (G3), EDTA-T (G4), and re-instrumentation with MAF using NaOCl and lubrificant, followed by EDTA-T (G5). The roots were split in the buccal-lingual direction and prepared for SEM analysis in cervical, middle, and apical thirds (9, 6, and 3 mm from the apex). Five blinded examiners evaluated the wall cleanliness using a scale from 1 to 5. Statistical analysis was performed using Kruskal-Wallis at 5% level of significance. Group G5 had the best results in all thirds, with significant statistical differences compared to all other groups in the middle and coronal third, and to G1 in the apical third. On the other hand, G1, only flushed with NaOCl, had the worst results, with statistical differences in all thirds compared to the other groups. The best cleanliness was achieved by G4 and G5 groups. The recapitulation of MAF in combination with irrigants improved the removal of calcium hydroxide medication better than an irrigant flush alone. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009; 107: 580-584)

Micro-hardness evaluation of a micro-hybrid composite resin light cured with halogen light, light-emitting diode and argon ion laser

This in vitro study aimed to determine whether the micro-hardness of a composite resin is modified by the light units or by the thickness of the increment. Composite resin disks were divided into 15 groups (n = 5), according to the factors under study: composite resin thickness (0 mm, 1 mm, 2 mm , 3 mm and 4 mm) and light units. The light activation was performed with halogen light (HL) (40 s, 500 mW/cm(2)), argon ion laser (AL) (30 s, 600 mW/cm(2)) or light-emitting diode (LED) (30 s, 400 mW/cm(2)). Vickers micro-hardness tests were performed after 1 week and were carried out on the top surface (0 mm-control) and at different depths of the samples. Analysis of variance (ANOVA) and Tukey tests (P a parts per thousand currency signaEuro parts per thousand 0.05) revealed no statistically significant difference among the light units for the groups of 0 mm and 1 mm thickness. At 2 mm depth, the AL was not statistically different from the HL, but the latter showed higher micro-hardness values than the LED. In groups with 3 mm and 4 mm thickness, the HL also showed higher micro-hardness values than the groups activated by the AL and the LED. Only the HL presented satisfactory polymerization with 3 mm of thickness. With a 4 mm increment no light unit was able to promote satisfactory polymerization.

The Effect of Fluoride Therapies on the Morphology of Bleached Human Dental Enamel

The aim of this in vitro study was to evaluate qualitatively the surface morphology of enamel bleached with 35% hydrogen peroxide (HP) followed by application of fluoridated agents. Forty intact pre molars were randomly distributed into four groups (n = 10), treated as follows: Group I (control group) remained stored in artificial saliva at 37 degrees C, Group II - 35% HP; Group III - 35% HP + acidulated fluoride (1.23%) and Group IV - 35% HP + neutral fluoride (2%). The experimental groups received three applications of bleaching gel and after the last application all specimens were polished. This procedure was repeated after 7 and 14 days, and during the intervals of applications, the specimens were stored in artificial saliva at 37 degrees C. Scanning electron microscopy (SEM) analysis showed superficial irregularities and porosities to varying degrees in bleached enamel compared to control group. Sample evaluation was made by attributing scores, and data were statistically analyzed using Kruskal-Wallis and Dunn tests (P < 0.05). SEM qualitative investigation demonstrated that 35% hydrogen peroxide affected human dental enamel morphology, producing porosities, depressions, and superficial irregularities at various degrees. These morphological changes were higher after the application of 1.23% acidulated fluoride gel. Microsc. Res. Tech. 74:512-516, 2011. (C) 2010 Wiley-Liss, Inc.

Evaluation of the lateral pterygoid muscle using magnetic resonance imaging

Objectives: The aims of this study were to evaluate the visibility of the lateral pterygoid muscle (LPM) in temporomandibular joint (TMJ) images obtained by MRI, using different projections and to compare image findings with clinical symptoms of patients with and without temporomandibular disorders (TMD). Methods: In this study, LPM images of 50 participants with and without TMDs were investigated by MRI. The images of the LPM in different projections of 100 TMJs from 35 participants (70 TMJs) with and 15 participants (30 TMJs) without clinical signs and symptoms of TMD were visible and analysed. Results: The oblique sagittal and axial images of the TMJ clearly showed the LPM. Hypertrophy (1.45%), atrophy (2.85%) and contracture (2.85%) were the abnormalities found in the LPM. TMD signs, such as hypermobility (11.4%), hypomobility (12.9%) and disc displacement (20.0%), could be seen in TMJ images. Related clinical symptoms, such as pain (71.4%), articular sounds (30.4%), bruxism (25.7%) and headache (22.9%), were observed. Conclusions: Patients with TMD can present with alterations in the LPM thickness. Patients without TMD also showed alterations, such as atrophy and contracture, in TMJ images. Recognition of alterations in the LPM will improve our understanding of clinical symptoms and pathophysiology of TMD, and may lead to a more specific diagnosis of these disorders. Dentomaxillofacial Radiology (2010) 39, 494-500. doi: 10.1259/dmfr/80928433