Harmonizing color measurements in dentistry using translucent tooth-colored materials.

Background: Since color measurements are relative, the discrepancy among different instruments is alarmingly high. This multicenter study evaluated the effectiveness of instrument calibration and inter-instrument harmonization of different spectrophotometers with the same optical geometry using tooth-colored, translucent dental materials.

Methods: The coordinating center (CC) spectrophotometer was calibrated using the NPL Ceram Series II set.

Evaluation of the Effects of Radiation Therapy on Muscle Contractibility and Skin Healing: An Experimental Study of the Cancer Treatment Implications.

Background: Radiotherapy can affect healthy cells, resulting in side effects. This study aimed to assess the impact of radiotherapy on soft tissue in surgical wounds in rats.

Methods: The animals were divided into four groups: control (S) group without irradiation, immediate irradiation (S-IIr) group receiving irradiation right after surgery, late irradiation (S-LIr) group receiving irradiation four weeks after surgery, and early irradiation (Ir-S) group receiving irradiation before surgery.

Development of Y-TZP/MWCNT-SiO nanocomposite for dental protheses.

Y-TZP/MWCNT-SiO nanocomposite was synthesized by co-precipitation and hydrothermal treatment methods. After the characterization of the MWCNT-SiO powder, specimens were obtained from the synthesized material Y-TZP/MWCNT-SiO by uniaxial pressing for a second characterization and later comparison of its optical and mechanical properties with the conventional Y-TZP. The MWCNT-SiO was presented in bundles of carbon nanotubes coated by silica (mean length: 5.

The Effect of a 10-MDP-Based Dentin Adhesive as Alternative for Bonding to Implant Abutment Materials.

Bonding to different dental restorative materials is challenging. This study aimed to evaluate the effect of a 10-MDP-based dentin adhesive on the shear bond strength (SBS) of self-adhesive resin cement (RC) to implant abutment materials. One hundred and twenty specimens were obtained from zirconia (ZO), cobalt-chromium alloy (CoCr), and commercially pure titanium (Ti), which were treated as follows (n = 10): control group-non-treated (CG), 10-MDP-based dentin adhesive (SB), light-cured SB (SB-LC), and zirconia primer (ZP).

Effects of staining and artificial aging on optical properties of gingiva-colored resin-based restorative materials.

Objectives: To evaluate CIEDE2000/CIELAB differences in color (ΔE/ΔE), and translucency parameter (ΔTP/ΔTP), and gloss of gingiva-colored resin-based restorative materials upon staining/aging.

Materials And Methods: Disc-shaped, 10 mm in diameter, and 2-mm-thick samples (n = 5/group) were made from giomer (Beautifil II gingiva), oligomer-based (crea.lign GUM gel), CAD/CAM polymethyl-methacrylate-based (IvoBase CAD), PMMA-based (ProBase Hot), and dimethacrylate-based (SR Nexco Paste Gingiva).

Effect of Staining and Aging on Translucency Parameter of CAD-CAM Materials.

Objectives: To evaluate different intervals of exposure to staining solutions and artificial aging on translucency parameter (TP) of CAD-CAM materials.

Material And Methods: One millimeter thick square-shaped specimens (N = 288) were cut from Cerasmart (CS), IPS e.max (IE), Lava Ultimate (LU), Shofu HC (SH), Vita Enamic (VE), and Vita Suprinity (VS) and were divided into laboratory and chairside polishing.

Staining and aging-dependent changes in color of CAD-CAM materials.

Statement Of Problem: Consumption of some beverages and aging may affect the color of dental materials used in fixed prosthodontics, but their effect on recently introduced materials is not well known.

Purpose: The purpose of this in vitro study was to evaluate staining, aging, and the exposure interval on color changes of computer-aided design and computer-aided manufacturing (CAD-CAM) resin nanoceramics (RNC), polymer-infiltrated ceramic-network (PICN) materials, and lithium silicate and lithium disilicate ceramics.

Material And Methods: A total of 288 square-shaped, 1-mm-thick specimens prepared from Cerasmart, IPS e.

Effect of Air-Particle-Abrasion Protocols on Surface Roughness and Early Biofilm Formation of Zirconia.

Purpose: The air-particle-abrasion on zirconia in the gingival area of connectors and pontics in fixed partial dentures appears to increase fracture resistance. This study evaluated 'in situ' biofilm formation on the zirconia surface after different air-particle-abrasion protocols.

Materials And Methods: Ninety sintered blocks (5 × 5 × 2 mm) of yttrium partially stabilised zirconia (Y-TZP) were obtained and randomised among nine groups according to the factors 'type of particle' (Alumina 50 and 110 µm; Cojet and Rocatec) and 'pressure' (2.

Systemic and local effects of radiotherapy: an experimental study on implants placed in rats.

Objectives: Evaluate the modulating effect of ionizing radiation, blood cytokine levels, and bone remodeling of the interface around the implant to understand the radiation mechanisms which can impair the implants receptor site.

Material And Methods: Sixty rats were submitted to grade V titanium implants in the femurs and were divided into the following groups: no-irradiation (N-Ir): control group with implant only; early-irradiation (E-Ir): implant + irradiation after 24 h; late-irradiation (L-Ir): implant + irradiation after 4 weeks; and previous-irradiation (P-Ir): irradiation + implant after 4 weeks. The animals in the E-Ir, L-Ir, and P-Ir groups were irradiated in two fractional stages of 15 Gy.

The Effect of Resection Angle on Stress Distribution after Root-End Surgery.

Introduction: This study aimed to investigate the influence of the resection angle on the stress distribution of retrograde endodontic treated maxillary incisors under oblique-load application.

Methods And Materials: A maxillary central incisor which was endodontically treated and restored with a fiber glass post was obtained in a 3-dimensional numerical model and distributed into three groups according to type of resection: control; restored with fiber post without retrograde obturation, R45 and R90 with 45º and 90º resection from tooth axial axis, respectively and restored with Fuji II LC (GC America). The numerical models received a 45 occlusal load of 200 N/cm on the middle of lingual surface.

Influence of implantoplasty on stress distribution of exposed implants at different bone insertion levels.

This study evaluated the effect of implantoplasty on different bone insertion levels of exposed implants. A model of the Bone Level Tapered implant (Straumann Institute, Waldenburg, Switzerland) was created through the Rhinoceros software (version 5.0 SR8, McNeel North America, Seattle, WA, USA).

The Role of New Removable Complete Dentures in Stimulated Salivary Flow and Taste Perception.

Purpose: To evaluate the effect of replacement of inadequate complete dentures on salivary flow and taste perception in geriatric patients.

Materials And Methods: Thirty-three patients, 13 males and 20 females, with a mean age of 64.4 years were submitted to stimulated and unstimulated salivary flow rate and salivary pH measurements, and sense of taste evaluation.

FEA and microstructure characterization of a one-piece Y-TZP abutment.

Objectives: The most important drawback of dental implant/abutment assemblies is the need for a fixing screw. This study aimed to develop an esthetic one-piece Y-TZP abutment to suppress the use of the screw.

Methods: Material characterization was performed using a bar-shaped specimen obtained by slip-casting to validate the method prior to prototype abutment fabrication by the same process.

Effect of the addition of silanated silica on the mechanical properties of microwave heat-cured acrylic resin.

Objectives: The purpose of this study was to evaluate the flexural strength and Vickers hardness of a microwave energy heat-cured acrylic resin by adding different concentrations of silane surface-treated nanoparticle silica.

Methods: Acrylic resin specimens with dimensions of 65 × 10 × 2.5 mm were formed and divided into five experimental groups (n = 10) according to the silica concentration added to the acrylic resin mass (weight %) prior to polymerisation : G1, without silica; G2, 0.

Evaluation of flexural resistance of a denture base acrylic resin reinforced with glass fiber and with composite resin.

The objective of this study was to evaluate the flexural strength of denture base resin reinforced with glass fibers and with a laboratorial composite resin. Group G1 was formed with specimens made of acrylic resin. Group G2 was formed with the same acrylic resin but reinforced with a glass-fiber system, and G3 was reinforced with the composite resin.

Effect of thickness of indirect restoration and distance from the light-curing unit tip on the hardness of a dual-cured resin cement.

This study evaluated the Knoop hardness and polymerization depth of a dual-cured resin cement, light-activated at different distances through different thicknesses of composite resin. One bovine incisor was embedded in resin and its buccal surface was flattened. Dentin was covered with PVC film where a mold (0.

Effect of light energy density on conversion degree and hardness of dual-cured resin cement.

This study evaluated the effect of different light energy densities on conversion degree (CD) and Knoop hardness number (KHN) of RelyX ARC (RLX) resin cement. After manipulation according to the manufacturer's instructions, RLX was inserted into a rubber mold (0.8 mm x 5 mm) and covered with a Mylar strip.

Evaluation of a new intraoral paralleling device for creating guiding planes: a pilot study.

Aim: The aim of the study was to assess the accuracy of a new intraoral paralleling device for creating proximal guiding planes for removable partial dental prostheses.

Methods And Materials: Thirty gypsum casts were divided into two groups in which the proximal surfaces of selected teeth were prepared using either a surveying device (Group 1) or the new ParalAB paralleling device (Group 2). In each cast guiding planes were prepared on the distal surface of the maxillary left canine (A), on the mesial and distal surfaces of the maxillary left second molar (B and C), and on the distal surface of the maxillary right canine (D).

Effect of light-curing method and indirect veneering materials on the Knoop hardness of a resin cement.

This study evaluated the Knoop hardness of a dual-cured resin cement (Rely-X ARC) activated solely by chemical reaction (control group) or by chemical / physical mode, light-cured through a 1.5 mm thick ceramic (HeraCeram) or composite (Artglass) disc. Light curing was carried out using conventional halogen light (XL2500) for 40 s (QTH); light emitting diodes (Ultrablue Is) for 40 s (LED); and Xenon plasma arc (Apollo 95E) for 3 s (PAC).

Effect of light-curing methods on resin cement Knoop hardness at different depths.

This study evaluated, using Knoop hardness test, the polymerization depth of Rely-X dual-cured resin cement activated by chemical reaction alone (control group) or by chemical/physical mode with light curing through a 1.5-mm-thick ceramic layer (HeraCeram). Bovine incisors had their buccal surface flattened and hybridized.

Shear bond strength of a ceramic to Co-Cr alloys.

Statement Of Problem: Different combinations of Co-Cr alloys bonded to ceramic have been used in dentistry; however, the bond strength of ceramic to metal can vary because of different compositions of these alloys.

Purpose: The purpose of this study was to evaluate the shear bond strength of a dental ceramic to 5 commercially available Co-Cr alloys.

Material And Methods: Five Co-Cr alloys (IPS d.

Effect of veneering materials and curing methods on resin cement knoop hardness.

This study evaluated the Knoop hardness of Enforce resin cement activated by the either chemical/physical or physical mode, and light cured directly and through ceramic (HeraCeram) or composite resin (Artglass). Light curing were performed with either conventional halogen light (QTH; XL2500) for 40 s or xenon plasma arc (PAC; Apollo 95E) for 3 s. Bovine incisors had their buccal surfaces flattened and hybridized.

Effect of light-curing method and cement activation mode on resin cement knoop hardness.

Purpose: To evaluate the Knoop hardness (KHN) of the resin cement Enforce activated by chemical/physical mode or physical mode solely; light-cured directly or through a 1.5 mm thick ceramic disc (HeraCeram) on shade DD2.

Materials And Methods: Light-curing was carried out using a conventional quartz tungsten halogen light (QTH) (XL2500) for 40 seconds at 700 mW/cm(2); light-emitting diodes (LED) (Ultrablue Is) for 40 seconds at 440 mW/cm(2); and Xenon plasma arc (PAC) (Apollo 95E) for 3 seconds at 1600 mW/cm(2).

Effect of the increase of energy density on Knoop hardness of dental composites light-cured by conventional QTH, LED and xenon plasma arc.

The aim of this study was to evaluate the effect of the increase of energy density on Knoop hardness of Z250 and Esthet-X composite resins. Cylindrical cavities (3 mm in diameter X 3 mm in depth) were prepared on the buccal surface of 144 bovine incisors. The composite resins were bulk-inserted and polymerized using different light-curing units and times: conventional QTH (quartz-tungsten-halogen; 700 mW/cm(2); 20 s, 30 s and 40 s); LED (light-emitting diode; 440 mW/cm(2); 20 s, 30 s and 40 s); PAC (xenon plasma arc; 1700 mW/cm(2); 3 s, 4.