Luis Felipe Valandro

Bio: Luis Felipe Valandro is an academic researcher. The author has an hindex of 1, co-authored 1 publications receiving 19 citations.

Influence of insertion techniques for resin cement and mechanical cycling on the bond strength between fiber posts and root dentin.

Abstract: Univ Estadual Paulista, UNESP, Inst Sci &Technol, BR-12245000 Sao Jose Dos Campos, SP, Brazil

A Multicenter Randomized Double-blind Controlled Clinical Trial of Fiber Post Cementation Strategies

Abstract: Clinical Relevance Both self-adhesive and regular resin cements obtained good survival rates and could be used for fiber post cementation.

Biological and antibacterial properties of a new silver fiber post: In vitro evaluation.

Abstract: Background The incorporation of nano silver particles (AgNPs) to improve antibacterial properties of dental materials has become increasingly common. The aim of the present study was to compare the antibacterial activity and cytotoxicity effects of different fiber posts: glass fiber post, quartz fiber post, nano fiber post and silver fiber post. Material and methods The antibacterial activity against S. mutans, S. salivarius and S. sanguis was evaluated by using the agar disc diffusion test (ADT). Four wells of 3x2 mm (one for each material) were made with a punch by removing the agar and filled with the materials to be evaluated. The size of the inhibition zone was calculated. An extract was made eluting the posts in cell culture medium using the surface area-to-volume ratio of approximately 1.25cm²/ml between the surface of the samples and the volume of medium. Cell cultures were then exposed to 100 μL of the extracts medium. After 24 h, cell viability was determined using the MTT assay. Results Silver fiber post was the only material showing a fair antibacterial effect against all the three streptococcal strains. The level of cytotoxicity of all the fiber posts tested was higher than 90% and therefore they were considered not cytotoxic. Conclusions The new silver fiber post reported a fair antibacterial activity. On the other hand all the fiber posts tested (including the post with incorporated AgNPs) proved to be biocompatible, suggesting that their application does not represent a threat to human health. Key words:Antibacterial activity, agar disc diffusion test, biocompatibility, fiber post, MTT test.

Relined fiberglass post: an ex vivo study of the resin cement thickness and dentin-resin interface

Abstract: The aim of this study was to evaluate the thickness of resin cements in the root thirds when using conventional fiberglass posts (CP) and relined fiberglass posts (RP) in weakened roots and to evaluate the morphological characteristics of the dentin-resin interface. Forty human maxillary anterior teeth had the crown sectioned below the cemento-enamel junction. The canals were endodontically treated and weakened with diamond burs. Teeth were divided into four groups (n = 10): Group 1 - CP + RelyX ARC; Group 2 - CP + RelyX U200; Group 3 - RP + RelyX ARC; and Group 4 - RP + RelyX U200. Prior to luting, 0.1% Fluorescein and 0.1% Rhodamine B dyes were added to an adhesive and resin cement, respectively. Slices were obtained from the apical, middle, and cervical thirds of the root. Confocal laser scanning microscopy images were recorded in four areas (buccal, lingual, mesial, distal) of each third. In each area, four equidistant measures of the resin cement were made and the mean value was calculated. The interface morphology was observed. The data were submitted to three-way ANOVA and Tukey's test (α = 0.05). The interaction between fiberglass posts, resin cement, and root thirds was significant (p < 0.0001). The resin cement thicknesses were significantly lower for RP in comparison with CP, except in the apical third. There was no significant difference between the resin cements for RP. There was formation of resin cement tags and adhesive tags along the root for RP. RP favored the formation of thin and uniform resin cement films and resin tags in weakened roots.

The effect of environmental pressure and resin cements on the push-out bond strength of a quartz fiber post to teeth root canals.

Abstract: AIM To evaluate the effect of environmental pressure changes on the bond strength between a fiber post and one of three resin cements using different mixing methods and modes of application. METHODOLOGY Sixty single-canal human teeth were divided into three groups (n = 20) and endodontically treated. Post spaces were prepared, and a quartz fiber post was secured with either a self-adhesive machine-mixed cement (RelyX Unicem, Aplicap), a self-adhesive hand-mixed cement (RelyX Unicem), or a self-etching dual-cured resin cement (Panavia F2). Half of each group was subjected to 24 pressure cycles from 0 to 5 atmospheres. The mean push-out bond strength of the posts was calculated and statistically analyzed using ANOVA and Tukey tests (α = 0.05). RESULTS Regardless of the pressure, Unicem Aplicap achieved the highest bond strength (P < 0.05). The bond strengths of all groups were significantly lower after they were subjected to the pressure cycles (P < 0.003), and they were lower in the apical regions. CONCLUSION Bond strengths between the fiber post and root canal can be affected by environmental pressure while the type of resin cements, their mixing methods and modes of application incorporated lower porosity, achieving higher bond strength.