Effect of monomer treatment and polymerisation methods on the bond strength of resin teeth to denture base material

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

Influence of Crown Ferrule Heights and Dowel Material Selection on the Mechanical Behavior of Root-Filled Teeth: A Finite Element Analysis

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

Evaluation of fungal adherence to plasma-modified polymethylmethacrylate

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

Effect of long-term water immersion on the fracture toughness of denture base and reline resins

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evaluation of Candida albicans adhesion and biofilm formation on a denture base acrylic resin containing silver nanoparticles

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 Superovulatory Protocols on In Vitro Production of Nellore (Bos indicus) Embryos

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

Adubação nitrogenada na implantação e na formação de pomares de caramboleira

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

Hardness and compressive strength of indirect composite resins: effects of immersion in distilled water

The aim of this study was to evaluate the effect of ageing in distilled water on the hardness and compressive strength of a direct composite resin Z100, a feldspatic porcelain (Noritake) and three indirect composites (Artglass, Solidex and Targis). For the Vickers hardness tests, five disk-shaped specimens (2 x 4 mm) of each material were prepared according to the manufacturers' instructions. The hardness tests were conducted using a Vickers diamond indentor. Compressive strength measurements were recorded on cylindrical specimens with a diameter of 6 mm and a length of 12 mm. The compression tests were carried out with a constant cross-head speed of 0.5 mm min(-1) on a mechanical test machine. For each material, 10 specimens were tested after 7 days of dry storage at 37 +/- 1 degreesC and 10 specimens were tested after water storage at 37 +/- 1 degreesC for 180 days. Noritake porcelain specimens showed higher hardness values than the composites. Among the composite materials, Z100 promoted the highest VHN values, regardless of the ageing periods. The results showed that Solidex and Z100 had the highest compressive strength values. Ageing in water reduced the hardness for all composites, but had no long-term effect on the compressive strength.

Histological evaluation of MTA as a root-end filling material

Aim To assess the histological response associated with grey mineral trioxide aggregate (GMTA) and zinc oxide eugenol (ZOE) as root-end filling materials in teeth where the root canals were not filled and the coronal access cavities were not restored.Methodology Periapical lesions were developed in 24 premolar teeth in three dogs. The root canals were prepared and half of them were dried, filled and the coronal access restored (closed). The remaining teeth were not root filled and no coronal restoration was placed (open). Apical root-end resections were performed 3 mm from the apex, and root-end cavities were prepared with ultrasonic tips. These were randomly filled with either ZOE or GMTA in the same number of specimens using MAPSYSTEM device. After 180 days the animals were killed and blocks of tissues removed and processed for histological examination. Periradicular tissue reaction was evaluated, including severity of inflammation and cementum formation. Statistical analysis was performed using ANOVA analysis and Tukey's test.Results A significant difference was found between the levels of inflammation in the periradicular tissues of the GMTA/closed group, compared with the ZOE/open and ZOE/closed groups (P < 0.05) but not between GMTA/closed and GMTA/open groups. Cementum formation was not found over any ZOE specimens but over MTA in all specimens. No microorganisms were found in the interface between the material and the dentinal walls.Conclusions GMTA was associated with less periapical inflammation and tissue response when used as a root-end filling material, even when no root filling or coronal restoration was present.

Mineral trioxide aggregate as a root canal filling material in reimplanted teeth. Microscopic analysis in monkeys

This study analyzed mineral trioxide aggregate (MTA) as a root canal filling material for the immediate reimplantation of monkey teeth. Four adult capuchin monkeys Cebus apella were used, which had their maxillary and mandibular lateral incisors on both sides extracted and reimplanted after 15 min. During the extra-alveolar period, the teeth were kept in saline solution and after reimplantation retention was performed with a stainless steel wire and composite resin for 14 days. After 7 days, the reimplanted teeth were submitted to endodontic treatment with biomechanics up to file n. 30 and irrigation with a saturated solution of calcium hydroxide [Ca(OH)(2)], and then divided into two study groups: group I - root canal filled with a Ca(OH)(2) paste, and group II - root canal filled with MTA. Radiographic follow up was performed at 30, 60 and 90 days postoperatively, and after 180 days the animals were killed and specimens were processed for histomorphological analysis. The results revealed that most specimens of both groups presented organized periodontal ligament with no inflammation. The resorptions observed were surface resorptions and were repaired by cementum. Both MTA and Ca(OH)(2) were good root canal filling materials for immediately reimplanted teeth, providing good repair and also allowing biological sealing of some lateral canals. There was no significant difference between the study groups (alpha = 29.60%).

Effects of pretreatment with rosemary (Rosmarinus officinalis L.) in the prevention of lipid oxidation in salted tilapia fillets

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

Liver HLA-G expression is associated with multiple clinical and histopathological forms of chronic hepatitis B virus infection

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Comparative study between atropine and hyoscine-N-butylbromide for reversal of detomidine induced bradycardia in horses

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

On the first nu(6) anti-aligned librating asteroid family of Tina

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