Influence of Different Surface Treatments on the Bond Strength of Yttria-Stabilized Tetragonal Zirconia Ceramic.

This study evaluates the shear bond strength (SBS) of yttria-stabilized tetragonal zirconia (Y-TZP) and resin cement after different surface treatments. Forty-eight ceramic cubes were divided into four groups ( = 12): G1 (control) sandblasting with AlO; G2-sandblasting with silica-coated AlO (Rocatec); G3-Rocatec + CO laser; and G4-CO laser + Rocatec. A metallic primer was applied to the pretreated ceramic.

Coordination tending towards an anti-phase relationship determines greater sway reduction during entrainment with a simulated partner.

The increased risk of falls in the older aged population demands the development of assistive robotic devices capable of effective balance support. For the development and increased user acceptance of such devices, which provide balance support in a human-like way, it is important to understand the simultaneous occurrence of entrainment and sway reduction in human-human interaction. However, sway reduction has not been observed yet during a human touching an external, continuously moving reference, which rather increased human body sway.

Sex differences in the association of postural control with indirect measures of body representations.

Besides anthropometric variables, high-order body representations have been hypothesised to influence postural control. However, this has not been directly tested before. Moreover, some studies indicate that sex moderates the relationship of anthropometry and postural control.

Immediate Effects of Vibrotactile Biofeedback Instructions on Human Postural Control.

Vibrotactile biofeedback can improve balance and consequently be helpful in fall prevention. However, it remains unclear how different types of stimulus presentations affect not only trunk tilt, but also Center of Pressure (CoP) displacements, and whether an instruction on how to move contributes to a better understanding of vibrotactile feedback.Based on lower back tilt angles (L5), we applied individualized multi-directional vibrotactile feedback to the upper torso by a haptic vest in 30 healthy young adults.

Five second photoactivation? A microhardness and marginal adaptation in vitro study in composite resin restorations.

Introduction: Studies defining the characteristics of light curing units and photoactivation methods are necessary to allow the correct choices to be made in daily practice. This study aimed to determine whether different photoactivation protocols for composite resins [periodic level shifting (PLS) - 5 second and soft-start] are able to maintain or enhance the mechanical properties and marginal adaptation of restorations.

Methods: Restorations were placed in bovine teeth using the following photoactivation methods: continuous light for 20 seconds (control group); PLS technology (PLS - 5 second group); and continuous light and a light guide tip distance of 6 mm after which the tip was placed at the surface of the restoration (soft-start group).

Immediate and short-term effects of in-office desensitizing treatments for dentinal tubule occlusion.

Objective: The objective of this in vitro study was to evaluate the immediate and short-term effects of laser neodymium-doped yttrium aluminum garnet (Nd:YAG) irradiation and in-office desensitizing treatment on dentin tubule occlusion.

Background Data: Literature shows a lack of long-lasting treatments for dentin hypersensitivity.

Methods: Forty-eight dentin slabs (4×4×2 mm) were ground flat, polished, and treated with 27% ethylenediaminetetraacetic acid (EDTA) to open the dentinal tubules.

Effect of CO2 laser on root caries inhibition around composite restorations: an in vitro study.

The aim of the present study was to investigate the in vitro effect of CO2 laser on the inhibition of root surface demineralization around composite resin restorations. For this purpose, 30 blocks obtained from human molar roots were divided into three groups: group 1 (negative control), cavity prepared with cylindrical diamond bur + acid etching + adhesive + composite resin restoration; group 2, cavity prepared with cylindrical diamond bur + CO2 laser (5.0 J/cm(2)) + acid etching + adhesive + composite resin; and group 3, cavity prepared with cylindrical diamond bur + CO2 laser (6.

The effect of fluoride therapies on the morphology of bleached human dental enamel.

The aim of this in vitro study was to evaluate qualitatively the surface morphology of enamel bleached with 35% hydrogen peroxide (HP) followed by application of fluoridated agents. Forty intact pre molars were randomly distributed into four groups (n = 10), treated as follows: Group I (control group) remained stored in artificial saliva at 37 °C, Group II - 35% HP; Group III - 35% HP + acidulated fluoride (1.23%) and Group IV - 35% HP + neutral fluoride (2%).

Argon ion laser curing depth effect on a composite resin.

The aim of this study was to define optimal power settings as well as curing time associated with evaluating the curing depth of a composite resin as a function of Vickers hardness. The tests were performed with a hybrid composite resin cured with a halogen lamp and argon ion laser, with different exposure times and power settings. The composite resin bulk technique was used using a black polypropylene matrix with thicknesses ranging from 1 to 4 mm and Vickers microhardness was measured on the opposite surface of the light activation.

Influence of aluminum oxide sandblasting associated with Nd:YAG or Er:YAG lasers on shear bond strength of a feldspathic ceramic to resin cements.

Objective: This in vitro study evaluated the influence of the surface pretreatment of a feldspathic ceramic on the shear bond strength of two different resin cements.

Background Data: Although several conventional surface treatments have been used on feldspathic ceramic, few studies have investigated the effects of an alternative surface treatment, the association of aluminum oxide sandblasting with Nd:YAG and Er: YAG lasers.

Methods: Sixty samples made of a feldspathic ceramic were divided into three groups (n = 20) and treated with (1) controlled-air abrasion with Al(2)O(3) + 10% hydrofluoric acid (HF), (2) Al(2)O(3) + Er:YAG laser, and (3) Al(2)O(3) +Nd:YAG laser.

Argon ion laser and halogen lamp activation of a dark and light resin composite: microhardness after long-term storage.

Unlabelled: The objective of this study was to evaluate in vitro light activation of the nano-filled resin composite Vita shade A1 and A3 with a halogen lamp (QTH) and argon ion laser by Knoop microhardness profile.

Materials And Methods: Specimens of nanofilled composite resin (Z350-3 M-ESPE) Vita shade A1 and A3 were prepared with a single increment inserted in 2.0-mm-thick and 3-mm diameter disc-shaped Teflon mold.

In vitro microleakage of composite restorations prepared by Er:YAG/Er,Cr:YSGG lasers and conventional drills associated with two adhesive systems.

Purpose: The objective of this in vitro study was to compare the degree of microleakage of composite restorations performed by lasers and conventional drills associated with two adhesive systems.

Materials And Methods: Sixty bovine teeth were divided into 6 groups (n = 10). The preparations were performed in groups 1 and 2 with a high-speed drill (HD), in groups 3 and 5 with Er:YAG laser, and in groups 4 and 6 with Er,Cr:YSGG laser.

Effect of feldspathic ceramic surface treatments on bond strength to resin cement.

Objective: The objective of this study was to evaluate the shear bond strength of resin cement to feldspathic ceramic with various surface treatments.

Background Data: Application of adhesive techniques is well established in restorative dentistry, yet the influence of surface treatments on the bond strength of resin cement to ceramic materials prior to luting or repair procedures remains unclear.

Methods: One hundred samples made of a feldspathic ceramic were divided into 10 groups (n = 10): (1) control (no treatment); (2) 10% hydrofluoric acid (HF); (3) 37% phosphoric acid (H(3)PO(4)); (4) 1.

Bond strength of a dentin bonding system using two techniques of polymerization: visible-light and argon laser.

Objective: The aim of this work was to study one dentin-bonding system associated with posterior teeth restorative composite resin by means of tensile bond strength tests varying the technique of polymerization: visible light and argon laser.

Background Data: Previous studies have demonstrated the ability of the argon laser to polymerize light-activated materials.

Methods: Sixty specimens were prepared by grinding the labial surface of bovine teeth embedded in acrylic resin.

Polymerization shrinkage evaluation of three packable composite resins using a gas pycnometer.

Modern restorative dentistry has been playing an outstanding role lately since composite resins, allied to adhesive systems, have been widely applied on anterior and posterior teeth restorations. The evolution of composite resins has mostly been verified due to the improvement of their aesthetic behavior and the increase in their compressive and abrasive strengths. In spite of these developments, the polymerization shrinkage inherent to the material has been a major deficiency that, so far, has been impossible to avoid.

Finite elements study of the Flexi Post and Flexi Flange post systems in a maxillary central incisor.

The use of post and core systems has become an excellent alternative for restoring endodontically treated teeth. The aim of this study was to evaluate the von Mises, maximal compressive and tensile stresses distribution using the Finite Element Method (FEM) on human teeth restored with different post and core systems. The analysis was made on endodontically treated maxillary central incisors.