Influence of simulated gastric juice on surface characteristics of CAD-CAM monolithic materials.

Statement Of Problem: How the surfaces of monolithic esthetic restorations behave in the presence of acidic substances is unclear.

Purpose: The purpose of this in vitro study was to evaluate the effect of simulated gastric juice on roughness, morphology, microhardness, substance loss, and color change of computer-aided design and computer-aided manufacturing (CAD-CAM) monolithic materials.

Material And Methods: Disks from Lava Ultimate, VITA ENAMIC, IPS e.

Effect of grinding and polishing on the roughness and fracture resistance of cemented CAD-CAM monolithic materials submitted to mechanical aging.

Statement Of Problem: The effect of clinical adjustments on the strength of cemented computer-aided design and computer-aided manufacturing (CAD-CAM) monolithic materials under aging challenge is unclear.

Purpose: The purpose of this in vitro study was to assess the surface roughness and fracture resistance (with or without mechanical aging) of cemented CAD-CAM monolithic materials submitted to grinding and polishing procedures.

Material And Methods: Disks of Lava Ultimate, Vita Enamic, crystallized Vita Suprinity, and IPS e.

Does airborne-particle abrasion before, rather than after, zirconia sintering lead to higher mechanical strength even under aging challenge?

Statement Of Problem: Information concerning the effect of airborne-particle abrasion before zirconia sintering on its strength after aging is lacking.

Purpose: The purpose of this in vitro study was to determine the influence of airborne-particle abrasion moment (before or after zirconia sintering), particle size, and aging on the mechanical strength of a yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) ceramic.

Material And Methods: Four hundred presintered zirconia disks were allocated to nonabraded (control) and abraded groups with 50 μm or 120 μm AlO particles before (50/BS or 120/BS) or after sintering (50/AS or 120/AS).

Wear resistance and abrasiveness of CAD-CAM monolithic materials.

Statement Of Problem: Computer-aided design and computer-aided manufacturing (CAD-CAM) restorations are in contact with the antagonist tooth, either a natural tooth or a restoration. Therefore, clinicians should be aware of the wear resistance of CAD-CAM materials and the wear behavior of the antagonist.

Purpose: The purpose of this in vitro study was to evaluate the wear resistance and abrasiveness of CAD-CAM materials.

Marginal Fit of Metal-Ceramic Copings: Effect of Luting Cements and Tooth Preparation Design.

Purpose: To evaluate the effect of the triad finish line design, axial wall convergence angle, and luting cement on the marginal fit of metal copings used in metal-ceramic crowns.

Materials And Methods: Schematic dies and their respective copings were cast in NiCr alloy. The dies exhibited the following finish line/convergence angle combinations: sloping shoulder/6°, sloping shoulder/20°, shoulder/6°, shoulder/20°.

Elastic Properties of Lithium Disilicate Versus Feldspathic Inlays: Effect on the Bonding by 3D Finite Element Analysis.

Purpose: To determine the elastic properties of five ceramic systems with different compositions (lithium disilicate vs. feldspathic ceramics) and processing methods and compare the stress distribution in premolars in the interface with inlays made with these systems loaded with the maximum normal bite force (665 N) using 3D finite element analysis (FEA).

Materials And Methods: The elastic properties of five ceramic restoration materials (IPS e.

The fracture resistance of a CAD/CAM Resin Nano Ceramic (RNC) and a CAD ceramic at different thicknesses.

Objectives: This study aimed to investigate the influence of restoration thickness to the fracture resistance of adhesively bonded Lava™ Ultimate CAD/CAM, a Resin Nano Ceramic (RNC), and IPS e.max CAD ceramic.

Methods: Polished Lava™ Ultimate CAD/CAM (Group L), sandblasted Lava™ Ultimate CAD/CAM (Group LS), and sandblasted IPS e.

Heat treatment following surface silanization in rebonded tribochemical silica-coated ceramic brackets: shear bond strength analysis.

Objective: This study aimed to evaluate the effects of heat treatment on the tribochemical silica coating and silane surface conditioning and the bond strength of rebonded alumina monocrystalline brackets.

Material And Methods: Sixty alumina monocrystalline brackets were randomly divided according to adhesive base surface treatments (n=20): Gc, no treatment (control); Gt, tribochemical silica coating + silane application; Gh, as per Gt + post-heat treatment (air flux at 100ºC for 60 s). Brackets were bonded to the enamel premolars surface with a light-polymerized resin and stored in distilled water at 37ºC for 100 days.

Zirconia-porcelain bonding: effect of multiple firings on microtensile bond strength.

Purpose: To determine the bond strength between zirconia and porcelain with varying numbers of veneer firing cycles.

Materials And Methods: Fifty specimens of zirconia veneered with feldspathic ceramic were submitted to one (1-firing), two (2-firings), three (3-firings), four (4-firings), or five (5-firings) firing cycles to sinter the porcelain. After the respective number of firings, the specimens were embedded into acrylic resin and sectioned into bars with a 1-mm2 cross-sectional area.

Toxicity of photodynamic therapy with LED associated to Photogem®: an in vivo study.

The aims of this study were to evaluate the effects of Photogem®-mediated photosensitization on rat palatal mucosa and the biodistribution of the photosensitizer in this tissue. A solution of Photogem® (500 or 1000 mg/l) was applied to the palatal mucosa for 30 min and the exposure time to blue LED (460 nm) was 20 min (144 J/cm(2)). At 0, 1, 3, and 7 days, palatal mucosa was photographed for macroscopic analysis.

Chemiluminescence as a PDT light source for microbial control.

The photodynamic therapy (PDT) is a combination of using a photosensitizer agent, light and oxygen that can cause oxidative cellular damage. This technique is applied in several cases, including for microbial control. The most extensively studied light sources for this purpose are lasers and LED-based systems.

Indirect cytotoxicity of a 35% hydrogen peroxide bleaching gel on cultured odontoblast-like cells.

The aim of this study was to evaluate the trans-enamel and trans-dentinal effects of a 35% hydrogen peroxide (H2O2) bleaching gel on odontoblast-like cells. Enamel/dentin discs obtained from bovine incisors were mounted in artificial pulp chambers (APCs). Three groups were formed: G1- 35% H2O2; G2- 35% H2O2 + halogen light application; G3- control.

Photodynamic therapy associating Photogem and blue LED on L929 and MDPC-23 cell culture.

To evaluate the cytotoxicity of PDT (photodynamic therapy) with Photogem associated to blue LED (light-emitting diode) on L929 and MDPC-23 cell cultures, 30000 cells/cm2 were seeded in 24-well plates for 48 h, incubated with Photogem (10, 25 or 50 mg/l) and irradiated with an LED source (460+/-3 nm; 22 mW/cm2) at two energy densities (25.5 or 37.5 J/cm2).