Characterization of Reinforced and Unreinforced Glass-Ceramic Veneers.

This study aimed to characterize the surface topography, effect of polishing on surface roughness, residual stresses, and hardness in two glass-ceramic veneers. Fifty-two (52) upper incisors were collected, prepared, and scanned for ceramic veneers. Half of the teeth were restored with veneers made up of feldspathic ceramic (FE), and the other half with zirconia-reinforced lithium silicate ceramic (SZ).

Evaluation of the accuracy and stress distribution of 3-unit implant supported prostheses obtained by different manufacturing methods.

The purpose of this in vitro study was to measure the vertical, positive-horizontal, and negative-horizontal misfit (VM, PHM, and NHM, respectively) of the zirconia three-element prosthetic framework, fabricated using different methods, and compare them with conventional fabrication methods (lost-wax casting). Furthermore, this study aimed to evaluate the influence of the misfit values on the biomechanical behavior of the 3-unit fixed prosthetic frameworks using three-dimensional finite element analysis (3D-FEA). Forty frameworks (n = 10) were fabricated as follow: G1, Cerec Bluecam; G2, iTero; G3, 3Series; and G4, conventional method.

Analysis of Vertical Marginal Adaptation of Zirconia Fixed Dental Prosthesis Frameworks Fabricated by the CAD/CAM System: A Randomized, Double-Blind Study.

Purpose: The purpose of this study was to evaluate the marginal adaptation of fixed dental prosthesis frameworks fabricated by computer-aided design/computer-assisted manufacture (CAD/CAM) with three different systems of data acquisition.

Materials And Methods: A total of 50 specimens were fabricated as follows: using the conventional method (Ni-Cr) (n=10); iTero/industrial milling (Group 1, n=10); Cerec Bluecam/industrial milling (Group 2, n=10); 3S/industrial milling (Group 3, n=10); and Cerec BlueCam/Sirona milling (Group 4, n=10). The specimens were numbered and randomized, and the vertical marginal discrepancy was analyzed.

Optical impression systems for CAD-CAM restorations.

Computer-aided design/computer-aided manufacturing images can be taken through either direct or indirect imaging. For the indirect systems, the digitalization is obtained from the impression material or cast, and for the direct ones the image is taken directly from the mouth using intraoral scanners.The direct acquisition systems have been constantly improved because these are less invasive, quicker, and more precise than the conventional method.

Effect of static and cyclic loading on ceramic laminate veneers adhered to teeth with and without aged composite restorations.

Purpose: Existing composite restorations on teeth are often remade prior to the cementation of fixed dental prostheses. The aim of this study was to evaluate the effect of static and cyclic loading on ceramic laminate veneers adhered to aged resin composite restorations.

Materials And Methods: Eighty sound maxillary incisors were collected and randomly divided into four groups: group 1: control group, no restorations; group 2: two Class III restorations; group 3: two Class IV restorations; group 4: complete composite substrate.

The adhesive system and root canal region do not influence the degree of conversion of dual resin cement.

Objectives: The aim of this study was to evaluate the influence of two adhesive systems and the post space region on the degree of conversion of dual resin cement and its bond strength to root dentin.

Material And Methods: One three-step etch-and-rinse (All-bond 2, Bisco) and another one-step self-etch (Xeno III, Dentsply) adhesive systems were applied on 20 (n=10) crownless bovine incisors, at 12-mm-deep post space preparation, and a fiber post (DT Light Post, Bisco) was cemented using a dual cure resin cement (Duo-Link, Bisco). Three transverse sections (3 mm) were obtained, being one from each study region (cervical, middle and apical).

Effect of different polymerization devices on the degree of conversion and the physical properties of an indirect resin composite.

Polymerization of indirect resin composites (IRC) is carried out in the 'laboratories using special photo-polymerization devices to achieve a higher degree of conversion (DC). Such devices present variation in chambers and light output which may have consequences on the chemical and physical properties of IRCs. This study evaluated the effect of different polymerization devices on the flexural strength, Vickers microhardness and DC of an IRC.

Bond strength of two resin cements on dentin using different cementation strategies.

Purpose: This study evaluated the microtensile bond strength of two resin cements to dentin either with their corresponding self-etching adhesives or employing the three-step "etch-and-rinse" technique. The null hypothesis was that the "etch-and-rinse" adhesive system would generate higher bond strengths than the self-etching adhesives.

Materials And Methods: Thirty-two human molars were randomly divided into four groups (N = 32, n = 8/per group): G1) ED Primer self-etching adhesive + Panavia F; G2) All-Bond 2 "etch-and-rinse" adhesive + Panavia F; G3) Multilink primer A/B self-etching adhesive + Multilink resin cement; G4) All-Bond 2 + Multilink.

Durability of the bond strength of self-adhesive resin cements to human dentin.

This study subjected two self-adhesive resin cements and two conventional resin cements to dry and aging conditions, to compare their microtensile bond strengths (microTBS) to dentin. Using four different luting systems (n = 10), 40 composite resin blocks (each 5 x 5 x 4 mm) were cemented to flat human crown dentin surfaces. The specimens were stored in water for 24 hours (37 degrees C), at which point each specimen was sectioned along two axes to obtain beams that were divided randomly into two groups: dry samples, which were tested immediately, and samples that were subjected to accelerated aging conditions (12,000 thermocycles followed by storage for 150 days).

Comparison of resin push-out strength to root dentin of bovine- and human-teeth.

Aim: To compare the push-out strength of bovine- and human-root dentin and, thus, evaluate the suitability of bovine-root dentin to substitute human-root dentin for bond strength testing.

Materials And Methods: Ten single-rooted human-teeth and ten bovine incisors were prepared using a #3 bur of a fiber post system (12 mm long). The posts were duplicated with resin cement (Duolink).

Fatigue resistance of teeth restored with fiber posts and different post cementation strengths.

This study sought to evaluate how different post cementation strategies affected the fatigue resistance of bovine teeth restored with glass fiber posts. The canals of 63 single-rooted bovine teeth (each 16 mm in length) were prepared to 9 mm using a preparation drill from a double-tapered fiber post system. Each specimen was embedded in a PVC cylinder using acrylic resin up to 3 mm of the most coronal portion of the specimen and was allocated into one of seven groups (n = 9) based on the strategies for cementation.

Effect of acid neutralization and mechanical cycling on the microtensile bond strength of glass-ceramic inlays.

Objectives: To evaluate the hypothesis that a process of hydrofluoric acid precipitate neutralization and fatigue load cycling performed on human premolars restored with ceramic inlays had an influence on microtensile bond strength results (MTBS).

Methods: MOD inlay preparations were performed in 40 premolars (with their roots embedded in acrylic resin). Forty ceramic restorations were prepared using glass-ceramic (IPS Empress).

Adhesive cementation of zirconia posts to root dentin: evaluation of the mechanical cycling effect.

This study evaluated the effect of mechanical cycling on the bond strength of zirconia posts to root dentin. Thirty single-rooted human teeth were transversally sectioned to a length of 16 mm. The canal preparation was performed with zirconia post system drills (CosmoPost, Ivoclar) to a depth of 12 mm.

Effect of adhesive system type and tooth region on the bond strength to dentin.

Purpose: This study evaluated the bond strength of two etch-and-rinse adhesive systems (two- and three-step) and a self-etching system to coronal and root canal dentin.

Materials And Methods: The root canals of 30 human incisors and canines were instrumented and prepared with burs. The posts used for luting were duplicated with dual resin cement (Duo-link) inside Aestheti Plus #2 molds.

Evaluation of light transmission through translucent and opaque posts.

Objectives: The transmission of light through translucent posts was observed, and the microhardness of light-cured cement used to secure these posts was evaluated at different depths.

Methods: Fifteen single-rooted standard bovine teeth, 16 mm in size, were used. The root canals were prepared using #3 drills Light-Post (five teeth) and Aestheti Post (five teeth) systems (BISCO), with a working-length of 12 mm.

Influence of brush type as a carrier of adhesive solutions and paper points as an adhesive-excess remover on the resin bond to root dentin.

Purpose: To evaluate the influence of the brush type as a carrier of priming adhesive solutions and the use of paper points as a remover of the excess of these solutions on the push-out bond strength of resin cement to bovine root dentin. The null hypotheses were that brush type and the use of paper points do not affect the bond strength.

Materials And Methods: The canals of 80 single-root bovine roots (16 mm in length) were prepared at 12 mm using the preparation drill (FRC Postec Plus, Ivoclar).

Surface conditioning of a composite used for inlay/onlay restorations: effect on muTBS to resin cement.

Purpose: To assess the effect of the composite surface conditioning on the microtensile bond strength of a resin cement to a composite used for inlay/onlay restorations.

Materials And Methods: Forty-two blocks (6 x 6 x 4 mm) of a microfilled composite (Vita VMLC) were produced and divided into 3 groups (N = 14) by composite surface conditioning methods: Gr1--etching with 37% phosphoric acid, washing, drying, silanization; Gr2--air abrasion with 50-lm Al203 particles, silanization; Gr3--chairside tribochemical silica coating (CoJet System), silanization. Single-Bond (one-step adhesive) was applied on the conditioned surfaces and the two resin blocks treated with the same method were cemented using RelyX ARC (dual-curing resin cement).

Effect of mechanical cycling on the push-out bond strength of fiber posts adhesively bonded to human root dentin.

This study evaluated the effect of mechanical cycling on the bond strength of fiber posts bonded to root dentin. The hypotheses examined were that bond strength is not changed after fatigue testing and bond strength does not present vast variations according to the type of fiber post. Sixty crownless, single-rooted human teeth were endodontically treated, with the space prepared at 12 mm.

Effects of mechanical cycling on the bonding of zirconia and fiber posts to human root dentin.

Purpose: To evaluate the effect of cyclical mechanical loading on the bond strength of a fiber and a zirconia post bonded to root dentin.

Materials And Methods: Forty single-rooted human teeth (maxillary incisors and canines) were sectioned, and the root canals were prepared at 12 mm. Twenty randomly seleced specimens received a quartz fiber post (FRC) (D.

Effect of post length on the fatigue resistance of bovine teeth restored with bonded fiber posts: a pilot study.

This study evaluated the influence of the cementation length of glass fiber-reinforced composite (FRC) on the fatigue resistance of bovine teeth restored with an adhesively cemented FRC. Thirty roots of single-rooted bovine teeth were allocated to 3 groups (n = 10), according to the ratio of crown length/root length (post cementation length): group 1 = 2/3, group 2 = 1/2, and group 3 = 1/1. The roots were prepared, the fiber posts (FRC Postec Plus) were cemented, and the specimens were submitted to 2 million mechanical cycles.

Effect of surface conditioning methods on the microtensile bond strength of resin composite to composite after aging conditions.

Objectives: This study evaluated the effect of two different surface conditioning methods on the repair bond strength of a bis-GMA-adduct/bis-EMA/TEGDMA based resin composite after three aging conditions.

Methods: Thirty-six composite resin blocks (Esthet X, Dentsply) were prepared (5 mm x 6 mm x 6 mm) and randomly assigned into three groups for aging process: (a) immersion in citric acid (pH 3.0 at 37 degrees C, 1 week) (CA); (b) boiling in water for 8h (BW) and (c) thermocycling (x5000, 5-55 degrees C, dwell time: 30s) (TC).

Microtensile bond strength between a quartz fiber post and a resin cement: effect of post surface conditioning.

Purpose: To test the bond strength between a quartz-fiber-reinforced composite post (FRC) and a resin cement. The null hypothesis was that the bond strength can be increased by using a chairside tribochemical silica-coating system.

Materials And Methods: Thirty quartz-FRCs (Light-Post) were divided into 3 groups according to the post surface treatment: G1) Conditioning with 32% phosphoric acid (1 min), applying a silane coupling agent; G2) etching with 10% hydrofluoric acid (1 min), silane application; G3) chairside tribochemical silica coating method (CoJet System): air abrasion with 30-microm SiOx-modified Al2O3 particles, silane application.

Effect of silica coating on flexural strength of fiber posts.

Purpose: Fiber-reinforced composite (FRC) posts can be air-abraded to obtain good attachment to the resin cement. This study tested the effect of silica coating on the flexural strength of carbon, opaque, and translucent quartz FRC posts.

Materials And Methods: Six experimental groups of FRC posts (n=10 per group) were tested, either as received from the manufacturer or after chairside silica coating (30-microm CoJet-Sand).

Evaluation of the flexural strength of carbon fiber-, quartz fiber-, and glass fiber-based posts.

This study investigated the flexural strength of eight fiber posts (one carbon fiber, one carbon/quartz fiber, one opaque quartz fiber, two translucent quartz fiber, and three glass fiber posts). Eighty fiber posts were used and divided into eight groups (n = 10): G1: C-POST (Bisco); G2: AESTHETI-POST (Bisco); G3: AESTHETI-PLUS (Bisco); G4: LIGHT-POST (Bisco); G5: D.T.