Search

Purpose: To determine the influence of mechanical properties of resin-based composites on the microtensile bond strength to dentin of all-in-one adhesives., Materials and Methods: Microtensile bond strengths were measured with the non-trimming technique for the experimental groups: 1) Bond Force/Estelite Σ (Tokuyama); 2) G-Bond Plus (GC)/Estelite Σ; 3) Bond Force/Gradia Direct Anterior (GC);4) G-Bond Plus/Gradia Direct Anterior; 5) Bond Force/Gradia Direct LoFlo (GC); 6) G-Bond Plus/Gradia Direct LoFlo. The following mechanical properties of the resin-based composites were assessed: tensile strength, flexural strength, tensile elastic modulus, shear elastic modulus, Poisson's ratio, Vicker's hardness, contraction stress. Three-dimensional models of microtensile beams were created for finite element analysis of the first principal stress values and distribution in the adhesive layer during microtensile testing. Statistical tests were applied to microtensile bond strength values (two-way ANOVA) and to data from mechanical tests (one-way ANOVA). In all the analyses, the level of significance was set at p < 0.05., Results: While the adhesive did not significantly influence microtensile bond strength, the composite was a significant factor. Regardless of the adhesive, Estelite Σ yielded significantly higher bond strengths than Gradia Direct Anterior and Gradia Direct LoFlo, that were comparable. Adhesive-composite interactions were not statistically significant. Estelite Σ had the highest Vicker's hardness, the highest tensile and shear elastic moduli, the lowest and closest to dentin Poisson's ratio. A more favorable stress distribution in the adhesive layer occurred in the Estelite Σ model., Conclusions: When comparing the bonding potential of several adhesives with the microtensile technique, the same resin composite should be used in all the experimental groups for building up the coronal portion.

Objectives: When coronal fracture occurs in anterior teeth, fragment reattachment can be a valid alternative to a direct restoration. The aim of this study was to evaluate the influence of the material and the technique used to reattach the fragment., Materials and Methods: Eighty sound maxillary and mandibular incisors were selected and randomly divided into eight groups (n = 10). The incisal third of each tooth was removed using a saw machine. The fragments in groups 1-4 were reattached using resin-based materials: group 1 adhesive, group 2 flow, group 3 composite, group 4 cement; in groups 5-8, the same materials mentioned before were used but a bevel was also performed on both labial and lingual surfaces. Shear bond strength (SBS) was calculated by applying a load incisal to the reattachment line. A two-way Anova was used to evaluate the influence of materials and techniques on the SBS., Results: The technique used was statistically significant (P < 0.001), while the material was not (P = 0.793)., Conclusions: The choice of material seems to have no influence on the SBS, whereas a bevel performed on the labial and lingual surfaces can significantly improve the SBS of the reattached fragment., (© 2011 John Wiley & Sons A/S.)

The aim of this study was to evaluate whether a post-cure heat-treatment may improve the flexural strength of two indirect resin-based composites. Tested factors were: material (Gradia Indirect, Gradia Forte), mass (opaqus dentin, dentin, enamel) and curing mode (light, light and heat). A three-point bending test appliance was developed according to ISO 4049/2000. Three-Way ANOVA and 2-Pameter Weibull cumulative distribution function were performed. Factors material and curing mode were significant (p < 0.001), while the mass type was not (p = 0.181). A post-cure heat treatment may be useful for enhancing the flexural strength of both materials.

Purpose: To evaluate the effects of storage condition and duration on the resistance to fracture of different fiber post systems (and to morphologically assess the post structure before and after storage., Methods: Three types of fiber posts (DT Light Post, GC Post, FRC Postect Plus) were divided in different groups (n = 12) according to the storage condition (dry at 37 degrees C; saline water at 37 degrees C; mineral oil at 37 degrees C and storage inside the roots of extracted human teeth immersed in saline water at 37 degrees C) and duration (6, 12 months). A universal testing machine loading at a 90 degrees angle was employed for the three-point bending test. The test was carried out until fracture of the post. A 3-way ANOVA and Tukey's test (alpha = 0.05) were used to compare the effect of the experimental factors on the fracture strength. Two posts of each group were observed before and after the storage using a scanning electron microscope., Results: Storage condition and post type had a significant effect on post fracture strength (P < 0.05). The interaction between these factors was significant (P < 0.05). Water storage significantly decreased the fracture strength, regardless of the post type and the storage duration. Storage inside roots, in oil, and at dry conditions did not significantly affect post fracture strength. SEM micrographs revealed voids between fibers and resin matrix for posts stored in water. Posts stored under the other conditions showed a compact matrix without porosities.

Aim: Several new irreversible hydrocolloid formulations have recently become available with claims of an improved dimensional stability by the manufacturers. The aim of this study was to evaluate the accuracy of casts made from alginate impression materials poured immediately and after specific storage periods., Methods and Materials: Five alginates were tested: CA 37 (Cavex); Jeltrate (Dentsply Caulk); Jeltrate Plus (Dentsply Latin America); Hydrogum 5 (Zhermack); and Alginoplast (Heraeus Kulzer). A master model was mounted on a special device and used to obtain the impressions. These impressions were stored at 23 degrees C and 100% relative humidity, then poured with gypsum immediately, and again after 24, 72 and 120 hours. The casts were measured and the data were analyzed by one way analysis of variance (ANOVA) and Tukey test at p<0.05., Results: The dimensional stability of the alginate impressions was both material and time dependent (p<0.05). After 24 hours of storage, only Alginoplast and Hydrogum 5 comply with the master model (p>0.05). After 72 and 120 hours, only Hydrogum 5 was dimensionally stable (p>0.05)., Conclusion: The dimensional stability of the alginate impressions is influenced by the selected material and the storage time., Clinical Significance: Alginate impressions should generally be poured immediately. However, some new types of alginate may have the pouring delayed.

The intestinal parasitosis is a world health problem. The countries which don't have any economic, sanitary or educational resources are the most affected. Perú doesn't scape of that situation and for this reason, it is necessary that health professionals should have clinical therapeutical and epidemiological acknowledgements in order to be applied efficiently in benefit of the community. This paper there is a review of newer treatment of the enteroparasitosis, regarding the classic drugs and the ones which have been recently introduced.

We present our experience in the investigation of Strongyloides stercoralis in the duodenal juice obtained by the "string capsule" o Enterotest, in 1,511 patients from the Gastroenterology Service of the National Hospital "Edgardo Rebagliati Martins" IPSS, between January 1985 to July 1990. We found 36 patients parasitized with Strongyloides stercoralis, an incidence of 2.4%. This method was good tolerated and have proved to be simple, fast, effective and allowing to examine simultaneously many patients at a very low cost.

We report the first clinical case of a patient with a severe hyper infestation due to Strongyloides stercoralis who developed a pancreatic pseudotumoral complication. Its clinical aspects, auxiliary exams, therapeutic schedule, evolution and the roentgenographic, ultrasound and TAC images are shown in this paper.