Mandibular Angle Fracture Treated With New Three-Dimensional Grid Miniplate

Fractures of the mandibular angle deserve particular attention because they represent the highest percentage of mandibular fractures and have the highest postsurgical complication rate, making them the most challenging and unpredictable mandibular fractures to treat. Despite the evolution in the treatment of maxillofacial trauma and fixation methods, no single treatment modality has been revealed to be ideal for mandibular angle fractures. Several methods of internal fixation have been studied with great variation in complications rates, especially postoperative infections. Recently, new studies have shown reduction of postsurgical complications rates using three-dimensional plates to treat mandibular angle fractures. Nevertheless, only few surgeons have used this type of plate for the treatment of mandibular angle fractures. The aim of this clinical report was to describe a case of a patient with a mandibular angle fracture treated by an intraoral approach and a three-dimensional rectangular grid miniplate with 4 holes, which was stabilized with monocortical screws. The authors show a follow-up of 8 months, without infection and with occlusal stability.

Effect of relining, water storage and cyclic loading on the flexural strength of a denture base acrylic resin

Objectives: This study investigated the effect of relining, water storage and cyclic loading on the ultimate flexural strength (FSU) and on the flexural strength at the proportional limit (FSPl) of a denture base acrylic resin (Lucitone 550-L).Methods: Rectangular bars of L were made (64 mm x 10 mm x 2 mm) and relined (1.3 mm) with four relining resins (Kooliner-K, Ufi Gel Hard-UGH, Tokuso Rebase Fast-TR and New Truliner-NT). In addition, specimens relined with L and intact L specimens were made (64 mm x 10 mm x 3.3 mm). A three-point flexural test was applied on the specimens (n = 10) after (1) polymerization; (2) water storage (30 days); (3) cyclic loading (10,000 cycles at 5 Hz) and (4) water storage (30 days) + cyclic loading. Data (MPa) were analyzed with three-way ANOVA and Tukey's HSD tests (alpha = 0.05). To test for a possible correlation between FSU and FSPl, a linear regression coefficient 'r' was calculated.Results: After water storage, L-UGH and L-TR demonstrated an increased FSU (41.4950.64 MPa and 49.95-57.36 MPa, respectively) (P < 0.05). Only L-TR demonstrated an increased FSPl (20.58-24.21 MPa) after water storage (P < 0.05). L-L had the highest FSU (between 78.57 and 85.09 MPa) and FSPl (between 31.30 and 34.17 MPa) (P < 0.05). The cyclic loading decreased the FSU and FSPl of all materials (P < 0.05). Regression analysis showed a strong linear correlation between the two variables (r = 0.941).Conclusions: Water storage improved the FSU of L-UGH and L-TR and the FSPl of L-TR. L-L produced the highest FSU and FSPl. The FSU and FSPl of all materials were detrimentally influenced by cyclic loading.

Effect of thermal cycling on microleakage between hard chairside relines and denture base acrylic resins

Objectives:Microleakage is a pre-stage of debonding between hard chairside relines and denture base acrylic resins. Therefore, it is important to assess them with regard to the longevity of the relined denture. This study investigated the effect of thermal cycling on the microleakage at the interface of three hard chairside reline resins and three denture base resins.Material and methods:Rectangular bars (12 mm x 3 mm x 3 mm) of Lucitone 550, Acron MC and QC 20 were made and relined with Kooliner, Tokuyama Rebase Fast II and Ufi Gel Hard, Lucitone 550, Acron MC and QC 20 resins. Specimens were divided into one control and two test groups (n = 10). In specimens of the control group, the microleakage was performed after the reline procedure. In Test Group 1, the specimens were stored for 24 h in distilled water at room temperature and in Test Group 2; the specimens were thermal cycled from 5 to 55 degrees C for 5000 cycles with a 30-s dwell time. Subsequently, all specimens were immersed in 50% silver nitrate solutions for 24 h. All specimens were sectioned longitudinally into three fractions and the lateral sections were examined (n = 20). Silver nitrate stain penetration was examined under a stereoscopic lens with x30 magnification, and the images were captured. Leica Qwin image analysis software was used to determine microleakage at the interface of the materials. Data were analysed using the Kruskal-Wallis test at a 95% level of significance.Results:For all cycles, there were no statistically significant differences between thermal cycled and non-thermal cycled groups (p > 0.05).Conclusion:It can be concluded that thermal cycling had no effect on the microleakage.

Flexural strength of acrylic resin repairs processed by different methods: water bath, microwave energy and chemical polymerization

Denture fractures are common in daily practice, causing inconvenience to the patient and to the dentists. Denture repairs should have adequate strength, dimensional stability and color match, and should be easily and quickly performed as well as relatively inexpensive. Objective: The aim of this study was to evaluate the flexural strength of acrylic resin repairs processed by different methods: warm water-bath, microwave energy, and chemical polymerization. Material and methods: Sixty rectangular specimens (31x10x2.5 mm) were made with warm water-bath acrylic resin (Lucitone 550) and grouped (15 specimens per group) according to the resin type used to make repair procedure: 1) specimens of warm water-bath resin (Lucitone 550) without repair (control group); 2) specimens of warm water-bath resin repaired with warm water-bath; 3) specimens of warm water-bath resin repaired with microwave resin (Acron MC); 4) specimens of warm water-bath resin repaired with autopolymerized acrylic resin (Simplex). Flexural strength was measured with the three-point bending in a universal testing machine (MTS 810 Material Test System) with load cell of 100 kgf under constant speed of 5 mm/min. Data were analyzed statistically by Kruskal-Wallis test (p<0.05). Results: The control group showed the best result (156.04 +/- 1.82 MPa). Significant differences were found among repaired specimens and the results were decreasing as follows: group 3 (43.02 +/- 2.25 MPa), group 2 (36.21 +/- 1.20 MPa) and group 4 (6.74 +/- 0.85 MPa). Conclusion: All repaired specimens demonstrated lower flexural strength than the control group. Repairs with autopolymerized acrylic resin showed the lowest flexural strength.

Effect of reline material and denture base surface treatment on the impact strength of a denture base acrylic resin

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

Reliability of a method for evaluating porosity in denture base resins

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

Influence of surface treatments on the flexural strength of denture base repair

Objective: The purpose of this study was to evaluate the flexural strength of repairs made with autopolymerising acrylic resin after different treatments of joint surfaces.Material and Methods: Fifty rectangular specimens were made with heat-polymerised acrylic resin and 40 were repaired with autopolymerising acrylic resin following joint surface treatments: group 1 (intact specimens), group 2 (chemical treatment: wetting with methyl-methacrylate for 180 s), group 3 (abraded with silicon carbide paper), group 4 (abraded and wetting with methyl-methacrylate for 180 s) and group 5 (without surface treatment). The flexural strength was measured by a three-point bending test using a universal testing machine with a 100 Kgf load cell in the centre of repair at 5 mm/min cross-head speed. All data were analysed using one-way ANOVA and Tukey HSD test for multiple comparisons (p < 0.05).Results: Among repaired specimens, groups 2 and 4 had 66.53 +/- 3.4 and 69.38 +/- 1.8 MPa mean values and were similar. These groups had superior flexural strength than groups 3 and 5 that were similar and had 54.11 +/- 3.4 and 51.24 +/- 2.8 MPa mean values, respectively. Group 1 had a mean value of 108.30 +/- 2.8 MPa being the highest result.Conclusion: It can be concluded that the treatment of the joint surfaces with methyl-methacrylate increases the flexural strength of denture base repairs, although the strength is still lower than that observed for the intact denture base resin. Abrasion with sandpaper was not able to influence the flexural strength of repaired denture bases.

Influence of different light sources and photo-activation methods on degree of conversion and polymerization shrinkage of a nanocomposite resin

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effect of different dental composite resins on the polymerization process

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

Ultrastructural features of the glandular region of the stomach of Piaractus mesopotamicus (Holmberg, 1887) with emphasis on the oxyntopeptic cell

The characteristics of the lining and glandular epithelial types of the wall of the stomach of pacu (Piaractus mesopotamicus Holmberg, 1887) were studied by transmission electron microscopy. Columnar mucous cells were observed in the lining epithelial surface and the glandular epithelium that invaginated in the lamina propria showed secretory cells or oxyntopeptic cells as called by some authors in the literature. The columnar epithelial cells are narrow and show a basal nucleus. They are rich in organelles and contain secretory granules of round or rectangular shape heterogeneously electron dense in the apical portion. In the basal region of the glands there are secretory cells. The luminal half of these cells has abundant tubules (tubulo-vesicular system) that communicate with the external medium. Deeper basally in the cytoplasm there are the nucleus, mitochondria of various shapes and other scattered organelles.

Influence of physical and chemical factors during foraging and culture of the symbiont fungus in Atta sexdens rubropilosa (Hymenoptera : Formicidae)

The aim of this paper is to investigate the influence of physical and chemical factors on transport and use of substrate for Atta sexdens rubropilosa workers. Three types of rectangular fragments were used to study the physical influence factors: filter paper with paraffin, filter paper without paraffin and polyester film. To study the chemical factors, some fragments were impregnated with organic extract of orange albedo, others were soaked with soybean oil and for the remaining ones nothing was applied. The following parameters were evaluated: (i) attractiveness of substrate for transport and number of loading workers per treatment; (ii) foraged material incorporation; (iii) rejection by numbers of fragments deposited in the garbage or beside the fungus garden. All the polyester film fragments carried out to the fungus garden were subsequently rejected. We verified that chemical factors of the substrate were more quickly detected by the workers, whereas physical factors were used as a criterion in the decision-making to reject or accept the substrate collected.

Photoeletrolytic system applied to remazol red brilliant degradation

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Características limnológicas da coluna d'água e dos efluentes de viveiros de criação de camarões-da-amazônia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Modal analysis of anisotropic diffused-channel waveguide by a scalar finite element method

A procedure to model optical diffused-channel waveguides is presented in this work. The dielectric waveguides present anisotropic refractive indexes which are calculated from the proton concentration. The proton concentration inside the channel is calculated by the anisotropic 2D-linear diffusion equation and converted to the refractive indexes using mathematical relations obtained from experimental data, the arbitrary refractive index profile is modeled by a. nodal expansion in the base functions. The TE and TM-like propagation properties (effective index) and the electromagnetic fields for well-annealed proton-exchanged (APE) LiNbO3 waveguides are computed by the finite element method.

Multiscale Fractal Descriptors and Polynomial Classifier for Partial Pixels Identification in Regions of Interest of Mammographic Images

Computer systems are used to support breast cancer diagnosis, with decisions taken from measurements carried out in regions of interest (ROIs). We show that support decisions obtained from square or rectangular ROIs can to include background regions with different behavior of healthy or diseased tissues. In this study, the background regions were identified as Partial Pixels (PP), obtained with a multilevel method of segmentation based on maximum entropy. The behaviors of healthy, diseased and partial tissues were quantified by fractal dimension and multiscale lacunarity, calculated through signatures of textures. The separability of groups was achieved using a polynomial classifier. The polynomials have powerful approximation properties as classifiers to treat characteristics linearly separable or not. This proposed method allowed quantifying the ROIs investigated and demonstrated that different behaviors are obtained, with distinctions of 90% for images obtained in the Cranio-caudal (CC) and Mediolateral Oblique (MLO) views.