CAD/CAM post-and-core using different esthetic materials: Fracture resistance and bond strengths.

Purpose: To evaluate the fracture resistance (FR), and push-out bond strengths (BS) of custom-made CAD/CAM post-and-cores manufactured with different esthetic materials.

Methods: 90 single-rooted extracted teeth were selected, endodontically treated and prepared to receive the posts. The specimens were randomly divided into three equal groups according to the material: hybrid ceramic Vita Enamic (HC); nano-ceramic resin composite Lava Ultimate (RC); and experimental epoxy-resin reinforced by glass-fiber (FG).

Mechanical properties of direct and indirect composites after storage for 24 hours and 10 months.

Objective: The objective of this study was to evaluate the diametral tensile strength (DTS) and Knoop hardness (KH) of direct (Filtek Z350-3M/ESPE and Charisma-Heraeus Kulzer) and indirect composites (Sinfony-3M/ESPE and Signum-Heraeus Kulzer) kept in storage for two periods of time, 24 hours and 10 months, in distilled water.

Methods: Twenty-five specimens of each material were prepared. DTS (n=10) was tested using a universal testing machine (Versat, model 2000) at a crosshead speed of 1.

Influence of diamondlike carbon-coated screws on the implant-abutment interface.

Purpose: To evaluate the implant-abutment interface area and the abutment screw loosening value when diamondlike carbon (DLC)-coated or titanium screws were used before and after cyclic loading.

Materials And Methods: Thirty-six implants were divided into four groups according to the type of connection (external hexagon [EH] or internal hexagon [IH]) and the type of abutment screw (with [EHD/IHD] or without [EHT/IHT] DLC coating). The implants were placed in epoxy resin-glass fiber composite, and crowns cast in a metal alloy were screwed to the implants.

Effect of the curing method and composite volume on marginal and internal adaptation of composite restoratives.

The aim of the present study was to evaluate the influence of curing methods and composite volumes on the marginal and internal adaptation of composite restoratives. Two cavities with different volumes (Lower volume: 12.6 mm(3); Higher volume: 24.

Influence of anatomic reference on the buccal contour of prosthetic crowns.

During clinical practice, when performing prosthetic rehabilitation with single crowns, improper reproduction of the dental contour by the dental laboratory is a common occurrence. Therefore, the present study evaluated the fidelity of the reproduction of the buccal contour in an upper left canine performed by three Dental Prosthesis Technicians (DPT) using the indirect laminate veneer technique. First, the DPTs confected the veneers based on a model obtained from the upper arch of a dental dummy, containing a replica of an upper left canine with a prosthetic preparation for a laminate veneer.

Effect of irradiance and light source on contraction stress, degree of conversion and push-out bond strength of composite restoratives.

Purpose: To evaluate the influence of five curing methods on contraction stress, stress rate, and degree of conversion (DC) of a composite and on bond strength of composite restoratives.

Methods: For the stress test, composite was applied between two 5-mm diameter glass rods, mounted in a servohydraulic machine. Stress rates were calculated as the change in stress vs.

Concurrence between the maxillary midline and bisector to the interpupillary line.

Purpose: Symmetry is one of the factors that contributes to facial harmony, and in oral rehabilitation it determines the success of esthetic treatment. Therefore, the aim of the present study was to analyze the axial symmetry between the bipupillar midline and maxillary central incisors midline of 102 dental students (both genders) distributed across five Brazilian dental schools.

Materials And Methods: Students with no teeth missing and who had never been subjected to any dental treatment were selected.

Degree of conversion and contraction stress development of a resin composite irradiated using halogen and LED at two C-factor levels.

This study verified the influence of curing methods and light sources on contraction stress, stress rate and degree of conversion (DC) of a restorative composite at two C-factor (CF) levels. For the stress test, composite (0.84 mm thick) was applied between two glass rods 5-mm in diameter mounted in a servohydraulic testing machine.

Influence of the curing method on the post-polymerization shrinkage stress of a composite resin.

The aim of this study was to evaluate the effect of different curing methods on the stress generated by the polymerization shrinkage of a restorative composite in two moments: immediately after light exposure and after 5 min. Photoactivation was performed using two different light sources: (1) xenon plasma arc (PAC) light (1,500 mW/cm2 - 3s) and (2) a quartz-tungsten-halogen (QTH) light with three light-curing regimens: continuous exposure (40 s at 800 mW/cm2 - CL); soft-start (10 s at 150 mW/cm2 and 30 s at 800 mW/cm2 - SS) and intermittent light [cycles of 4 s (2 s with light on at 600 mW/cm2 and 2 s of light off), for 80s - IL]. The composite resin was applied between two 5-mm diameter metallic rods, mounted in a servohydraulic machine.

Effect of different photoactivation methods on the bond strength of composite resin restorations by push-out test.

Objective: Modulated curing methods could lead to a higher probability of bond preservation. Therefore, the aim of this study was to evaluate the effect of 7 curing methods on bond strength of composite resin restorations.

Method And Materials: Seventy bovine incisors were selected.

Modulated photoactivation methods: Influence on contraction stress, degree of conversion and push-out bond strength of composite restoratives.

Objectives: Verify the influence of curing methods on contraction stress, stress rate, and degree of conversion (DC) of a restorative composite and on bond strength of composite restoratives.

Methods: For the stress test, composite (0.84 mm thick) was applied between two 5-mm diameter glass rods, mounted in a servohydraulic machine.

Marginal adaptation of composite restorations photoactivated by LED, plasma arc, and QTH light using low-modulus resin liners.

Purpose: The aim of this study was to evaluate the influence of resin liners on the marginal adaptation to dentin of resin composite restorations photoactivated by a conventional quartz-tungsten halogen lamp (QTH), light emitting diodes (LED), and a plasma arc light (PAC).

Materials And Methods: The buccal surfaces of 120 bovine incisors were ground until a flat dentin area was obtained. A circular cavity (4 mm in diameter x 1.

Relationship between bond strength and marginal and internal adaptation of composite restorations photocured by different methods.

Objective: This study evaluated the relationship between bond strength and marginal and internal adaptation of composite restorations photocured using different methods with a quartz-tungsten-halogen light.

Material And Methods: A push-out test was performed to evaluate bond strength of conical restorations in 50 bovine incisors. To evaluate marginal (external) and internal restoration adaptation, 50 circular all-enamel margin preparations were done in bovine incisors.

Dye staining gap test: an alternative method for assessing marginal gap formation in composite restorations.

Objective: The aim of this study was to evaluate and compare marginal adaptation of composite restorations assessed by a dye staining method and by scanning electron microscopy (SEM) analysis.

Material And Methods: Twenty bovine incisors were selected and ground flat to expose dentin. Two cylindrical cavities were prepared on the central area of flattened surfaces.

Effect of resin liners and photoactivation methods on the shrinkage stress of a resin composite.

Purpose: This study was undertaken to evaluate the effect of three different photoactivation methods on the polymerization shrinkage stress of a resin composite using different resin liners.

Materials And Methods: Three photoactivation methods using a quartz-tungsten-halogen light were evaluated: continuous light, soft start, and intermittent light. Three lining groups were tested: one or three coats of adhesive, and flowable composite.

Association of photoactivation methods and low modulus liners on marginal adaptation of composite restorations.

The aim of this study was to evaluate the effect of photoactivation methods, resin liners, and the association of these techniques on the marginal adaptation of composite restorations. One-hundred-and-twenty bovine incisors were selected. A circular cavity was prepared in a flat dentin area on the buccal surface and the Scotchbond Multi Purpose system was applied.

Comparative study of the surface roughness of Ormocer-based and conventional composites.

The aim of this study was to evaluate the surface roughness of two Ormocer-based resin composites before and after mechanical toothbrushing. The study compared the brands Admira and Definite with composites based on conventional monomer systems (Bis-GMA, Bis-EMA, UEDMA e TEGDMA), Z250 and A110. Eight samples of each material with 4mm in diameter and 2mm in height were prepared using a metallic mold.

Effect of different photoactivation methods on the polymerization depth of a light-activated composite.

This study verified the polymerization depth of the composite Z100 (3M Dental Products) by Knoop Hardness test using four photoactivation methods. Twenty cylindrical specimens (5 mm in diameter by 5 mm in height) were prepared in a metallic mold and photoactivated by one of the four methods: continuous light (520 mW/cm2 for 40 seconds); stepped light (150 mW/cm2 for 10 seconds followed by 520 mW/cm2 for 30 seconds); intermittent light (cycle of 1 second, 1/2 second with the light on and 1/2 second with the light off for 60 seconds at 520 mW/cm2) and Xenon plasma are (1370 mW/cm2 for 3 seconds). Knoop hardness measurements were obtained on the surface, at the depths of 1.