Assessment of the chemical solubility of experimental and commercial lithium silicate glass-ceramics.

Objective: This study aimed to evaluate the chemical solubility (CS) and conduct a comprehensive physicochemical characterization of several experimental and commercial lithium silicate-based glass-ceramics towards an understanding of the chemical processes governing dissolution in these glass-ceramics.

Methodology: Glass-ceramic (GC) samples were categorized into two groups: experimental materials featuring lithium metasilicate crystals (GCE1 and GCE2); and five commercial brands relying mostly on lithium disilicate (Celtra®Duo, IPS e.max®CAD, Straumann®n!ce®, CEREC Tessera™, and VITA Suprinity®).

Effect of Grinding and Regenerative Heat Treatment on the Fracture Resistance of a Zirconia/Porcelain Veneer Interface.

Purpose: To experimentally assess the effect of regenerative heat treatment (HT) on yttria-stabilized tetragonal zirconia polycrystalline ceramic (Y-TZP) to guarantee veneer adhesion strength.

Materials And Methods: One surface of bar-shaped Y-TZP specimens was ground (G) with a diamond stone, while the control samples (C) were not. Groups C900 and G900 were submitted to HT at 900°C for 60 min, whereas groups C1000 and G1000 were submitted to HT at 1000°C for 30 min.

Surface properties of a new lithium disilicate glass-ceramic after grinding.

This study aimed to evaluate the effect of grinding on some surface properties of two lithium disilicate-based glass-ceramics, one experimental new product denominated LaMaV Press (UFSCar-Brazil) and another commercial known as IPS e-max Press (Ivoclar), in the context of simulated clinical adjustment. Discs (N = 24, 12 mm in diameter) were separated into four groups: LaMaV Press with no grinding (E), LaMaV Press after grinding (EG), IPS e-max Press with no grinding (C), and IPS e-max Press after grinding (CG). A 0.

Does Diamond Stone Grinding Change the Surface Characteristics and Flexural Strength of Monolithic Zirconia?

Purpose: The present study evaluated the effect of grinding on the surface morphology, mean roughness, crystalline phase, flexural strength, and Weibull modulus of monolithic (MZ) and conventional (CZ) zirconias.

Methods And Materials: CZ and MZ bars and square-shaped specimens were distributed into three subgroups, combining grinding (G) and irrigation (W) with distilled water: Ctrl (Control: no grinding, 20 × 4 × 1.2 mm and 12 × 1.

Mechanical and Surface Properties of Monolithic Zirconia.

Purpose: This study compared monolithic zirconia with conventional ones based on mean roughness (Ra), Vickers hardness (VHN), topography, transmittance, grain size, flexural strength (FS), Weibull modulus, and fractographic behavior.

Methods And Materials: One monolithic (Prettau Zircon [PR group]) and two conventional (ICE Zirkon Transluzent [IZ group] and BloomZir [BL group]) zirconias were used. Specimens were tested using a profilometer, a microhardness tester, a scanning electron microscope, a spectrophotometer, and a Universal Testing Machine (EMIC DL 2000).

Custom Cast Ball Attachments Used on Outdated Implants to Restore a Maxillary Implant-Supported Overdenture.

The lack of compatible prosthetic components can be a complication during oral rehabilitation using outdated implants. The aim of the present clinical report was to describe an alternative technique for the fabrication of a maxillary implant-supported overdenture in a patient with 20-year-old dental implants using castable spherical patterns and ball attachments. The patient had been wearing a relined bar/clip overdenture in the mandible on 4 external-hexagon dental implants and a relined complete denture in the maxilla on 4 internal-hexagon implants due to abutment screw fracture inside of the implants, losing the attachment system.

Y-TZP zirconia regeneration firing: Microstructural and crystallographic changes after grinding.

This study evaluated microstructural and crystallographic phase changes after grinding (G) and regeneration firing/anneling (R) of Y-TZP ceramics. Thirty five bars (Lava and Ice Zirkon) were divided: Y-TZP pre-sintered, control (C), regeneration firing (R), dry grinding (DG), dry grinding+regeneration firing (DGR), wet grinding (WG) and wet grinding+regeneration firing (WGR). Grinding was conducted using a diamond bur and annealing at 1,000°C.

Characterization of a Diamond Ground Y-TZP and Reversion of the Tetragonal to Monoclinic Transformation.

Purpose: To characterize the surface of an yttria-stabilized zirconia (Y-TZP) ceramic after diamond grinding in terms of its crystalline phase, morphology, mean roughness (Ra), and wettability as well as to determine a thermal treatment to reverse the resulting tetragonal to monoclinic (t-m) transformation.

Methods And Materials: Y-TZP specimens were distributed into different groups according to the actions (or no action) of grinding and irrigation. Grinding was accomplished using a diamond stone at a low speed.

Zirconia changes after grinding and regeneration firing.

Statement Of Problem: Despite improvements in computer-aided design and computer-aided manufacturing (CAD-CAM) systems, grinding during either laboratory procedures or clinical adjustments is often needed to modify the shape of 3 mol(%) yttria-tetragonal zirconia polycrystal (3Y-TZP) restorations. However, the best way to achieve adjustment is unclear.

Purpose: The purpose of this in vitro study was to evaluate the microstructural and crystallographic phase changes, flexural strength, and Weibull modulus of a 3Y-TZP zirconia after grinding with or without water cooling and regeneration firing.

Effect of Grinding and Resintering on the Fatigue Limit and Surface Characterization of a Y-TZP Ceramic.

This study evaluated the effect of grinding protocols and resintering on flexural fatigue limit and surface characterization of LavaTM Y-TZP. Bar-shaped specimens (20×4.0×1.

Effects of whitening dentifrice on yttria-stabilized tetragonal zirconia polycrystal surfaces after simulating brushing.

Statement Of Problem: The changes that occur after brushing yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) are unknown. These changes may favor the retention of microorganisms and chemisorption of water, impairing its longevity.

Objective: The purpose of this in vitro study was to evaluate the effects of a whitening dentifrice on Y-TZP surfaces after simulating 10 years of brushing.

An alternative technique for fabrication of frameworks in an immediate loading implant fixed mandibular prosthesis.

The oral rehabilitation of edentulous patients with immediate loading has become a safe procedure with high predictability. The success is related to immediate fabrication of a passive fit framework to attach the implants. Based on these considerations, this case report shows an alternative technique for mandibular rehabilitation using implants immediately loaded, where the framework was fabricated using cylinders with internal reinforcement and precast pieces, electrowelding, and conventional welding providing esthetics and function to the patient in a short period of time.

A castor oil-containing dental luting agent: effects of cyclic loading and storage time on flexural strength.

Favorable results in the use of castor oil polyurethane (COP) as pulp capping, membrane material, sealer, mouthwash and in bone repair, associated with the fact that Ricinus communis is not derived from petroleum and it is abundant in Brazil, encourage researches in the development of luting agents. Objectives This study compared the flexural strength (FS) of a castor oil-containing dental luting agent with a weight percentage of 10% (wt%) of calcium carbonate (COP10) with RelyX ARC (RX) after mechanical cycling (MC) and distilled water storage. Material and Methods Sixty-four specimens (25x2x2 mm) were fabricated and divided into two groups, COP10 and RX (control).

Effect of surface and heat treatments on the biaxial flexural strength and phase transformation of a Y-TZP ceramic.

Purpose: To evaluate the effect of grinding and airborne-particle abrasion on the biaxial flexural strength (BFS) and phase transformation of a Y-TZP ceramic, and examine whether sintering the veneering porcelain renders the previous heat treatment recommended by the manufacturer unnecessary.

Materials And Methods: Lava zirconia specimens (N = 108) were obtained with the following dimensions: 14.0 mm diameter × 1.

Modified indexing technique for the immediate interim restoration of a dental implant.

Because of the functional and esthetic requirements of patients, different techniques have been proposed to reduce the time between dental implant placement and interim restoration fabrication. This article describes a modified indexing technique by using a surgical template for open-tray impression and definitive cast development during immediate loading procedures. This technique does not use a complete impression of the oral cavity and, therefore, is more comfortable, less time consuming, and less expensive.

In vitro comparisons of casting retention on implant abutments among commercially available and experimental castor oil-containing dental luting agents.

Statement Of Problem: Although cement-retained implant prostheses are widely used, the quantification of optimal retention remains controversial, and new dental luting agents should be evaluated.

Purpose: The purpose of this study was to compare, in vitro, the casting retention on implant abutments after cementation with 3 commercially available luting agents and an experimental luting agent (castor oil polyurethane, COP) with variable weight percentages (wt%) of calcium carbonate (CaCO3).

Material And Methods: Seventy-two palladium-silver cast copings were fabricated and divided into 6 groups: Temp Bond interim cement (TB); zinc phosphate cement (ZP); Rely X ARC resin cement (RX); pure COP (COP); COP + 10% wt% CaCO3 filler (COP 10); and COP + 50% wt% CaCO3 filler (COP 50).

Ricinus communis treatment of denture stomatitis in institutionalised elderly.

This study compared the effectiveness of Ricinus communis (RC) with Nystatin (NYS) and Miconazole (MIC) in the treatment of institutionalised elderly with denture stomatitis (DS). They (n = 30) were randomly distributed into three groups: MIC, NYS or RC. Clinical and mycological evaluations were performed prior to the use of the antifungal (baseline) and repeated after 15 and 30 days of treatment.

Radiopacity evaluation of contemporary luting cements by digitization of images.

Objective. The aim of this study was to evaluate the radiopacity of two conventional cements (Zinc Cement and Ketac Cem Easymix), one resin-modified glass ionomer cement (RelyX Luting 2) and six resin cements (Multilink, Bistite II DC, RelyX ARC, Fill Magic Dual Cement, Enforce and Panavia F) by digitization of images. Methods.

Comparison of the accuracy of plastic and metal stock trays for implant impressions.

Purpose: This in vitro study evaluated the dimensional accuracy of two impression techniques (tapered and splinted) with two stock trays (plastic and metal) for implant-supported prostheses.

Materials And Methods: A master cast with four parallel abutment analogs and a passive framework were fabricated. Polyvinyl siloxane impression material was used for all impressions with two metal stock trays and two plastic stock trays (closed and open trays).

Diametral tensile strength and film thickness of an experimental dental luting agent derived from castor oil.

Unlabelled: The need to develop new dental luting agents in order to improve the success of treatments has greatly motivated research.

Objective: The aim of this study was to evaluate the diametral tensile strength (DTS) and film thickness (FT) of an experimental dental luting agent derived from castor oil (COP) with or without addition of different quantities of filler (calcium carbonate - CaCO3).

Material And Methods: Eighty specimens were manufactured (DTS N=40; FT N=40) and divided into 4 groups: Pure COP; COP 10%; COP 50% and zinc phosphate (control).

Noncarious cervical lesions and their association with toothbrushing practices: in vivo evaluation.

Objectives: This pilot study aims to investigate the prevalence of noncarious cervical lesions (NCCLs) in a student population at the Faculty of Dentistry of Araçatuba–UNESP and to assess the potential relation between buccal hygiene habits and the presence and number of NCCLs.

Methods: This study was conducted with a sample of 58 young volunteers (15 men and 43 women; mean age, 23.6 ± 1.

Influence of microwave sterilization on the cutting capacity of carbide burs.

Objective: This study compared the cutting capacity of carbide burs sterilized with microwaves and traditional sterilization methods.

Material And Methods: Sixty burs were divided into 5 groups according to the sterilization methods: dry heat (G1), autoclave (G2), microwave irradiation (G3), glutaraldehyde (G4) or control - no sterilization (G5). The burs were used to cut glass plates in a cutting machine set for twelve 2.