Effect of cleanser solutions on the color of acrylic resins associated with titanium and nickel-chromium alloys.

This study evaluated the effect of cleanser solutions on the color of heat-polymerized acrylic resin (HPAR) and on the brightness of dental alloys with 180 immersion trials. Disk-shaped specimens were made with I) commercially pure titanium, II) nickel-chromium-molybdenum-titanium, III) nickel-chromium molybdenum, and IV) nickel-chromium-molybdenum beryllium. Each cast disk was invested in the flasks, incorporating the metal disk into the HPAR.

Tensile and flexural strength of commercially pure titanium submitted to laser and tungsten inert gas welds.

This study evaluated the tensile and flexural strength of tungsten inert gas (TIG) welds in specimens made of commercially pure titanium (CP Ti) compared with laser welds. Sixty cylindrical specimens (2 mm diameter x 55 mm thick) were randomly assigned to 3 groups for each test (n=10): no welding (control), TIG welding (10 V, 36 A, 8 s) and Nd:YAG laser welding (380 V, 8 ms). The specimens were radiographed and subjected to tensile and flexural strength tests at a crosshead speed of 1.

Effect of investment type and mold temperature on casting accuracy and titanium-ceramic bond.

This study evaluated the casting accuracy of crown margins and metal-ceramic shear bond strength (SBS) of pure titanium injected into casting molds made using 2 investment types at 3 mold temperatures. Sixty crown (30-degree beveled finish line) and 60 cylinder (5mm diameter × 8mm high) patterns were divided into 6 groups (n=10), and cast using a phosphate-bonded investment (P) and a magnesium oxide-bonded investment (U), at 400°C (groups P400 and U400), 550°C (groups P550 and U550) and 700°C (groups P700 and U700) mold temperatures. Crown margins were recorded in impression material, the degree of marginal rounding was measured and margin length deficiencies (µm) were calculated.

Effect of denture cleansers on metal ion release and surface roughness of denture base materials.

Chemical disinfectants are usually associated with mechanical methods to remove stains and reduce biofilm formation. This study evaluated the effect of disinfectants on release of metal ions and surface roughness of commercially pure titanium, metal alloys, and heat-polymerized acrylic resin, simulating 180 immersion trials. Disk-shaped specimens were fabricated with commercially pure titanium (Tritan), nickel-chromium-molybdenum-titanium (Vi-Star), nickel-chromium (Fit Cast-SB Plus), and nickel-chromium-beryllium (Fit Cast-V) alloys.

Shear bond strength of repairs in porcelain conditioned with laser.

The aim of this study was to evaluate the shear bond strength of repairs in porcelain conditioned with laser. Sixty porcelain discs were made and six groups were formed (n = 10): G1: conditioning with laser with potency 760 mW; G2: conditioning with laser with potency 760 mW and application of 37% phosphoric acid for 15 s; G3: conditioning with laser with potency 900 mW; G4: conditioning with laser with potency 900 mW and application of 37% phosphoric acid for 15 s; G5: application of 37% phosphoric acid for 15 s (group control) and G6: application of 10% hydrofluoric acid for 2 min. The composite resin was insert of incremental layers at the porcelain surface aided with a metal matrix, and photoactivation for 20 s each increment.

Shear bond strength between Ni-Cr alloy bonded to a ceramic substrate.

Introduction: The aim of this study was to evaluate the shear bond strength between a Ni-Cr alloy and a ceramic system submitted or not to thermocycling.

Materials And Methods: Forty-eight cylinder blocks of Ni-Cr with 3.0 mm diameter by 4.

Analysis of short implants and lateralization of the inferior alveolar nerve with 2-stage dental implants by finite element method.

There are difficulties for dental implant use in posterior mandible when there is little bone height for implant placement. Among the treatment alternatives available, there is no direct comparison between short implants and conventional implants placed with lateralization of the inferior alveolar nerve. The present study aimed to comparatively evaluate the risk of peri-implant bone loss of the above treatments.

Effect of different cleansers on the surface of removable partial denture.

Removable partial dentures (RPD) demand specific hygienic cleaning and the combination of brushing with immersion in chemical solutions has been the most recommended method for control of biofilm. However, the effect of the cleansers on metallic components has not been widely investigated. This study evaluated the effect of different cleansers on the surface of RPD.

Evaluation of anodic behavior of commercially pure titanium in tungsten inert gas and laser welds.

Purpose: This study evaluated the resistance to corrosion in welds made with Tungsten Inert Gas (TIG) in specimens made of commercially pure titanium (cp Ti) in comparison with laser welds.

Materials And Methods: A total of 15 circular specimens (10-mm diameter, 2-mm thick) were fabricated and divided into two groups: control group-cp Ti specimens (n = 5); experimental group-cp Ti specimens welded with TIG (n = 5) and with laser (n = 5). They were polished mechanically, washed with isopropyl alcohol, and dried with a drier.

An easy technique to obtain articulated casts using the palate for the interocclusal record.

This article describes a highly efficient technique to obtain articulated casts. Interocclusal recording is carried out using the palate as an area of registration without having to remove or section provisional prostheses while also maintaining the established vertical dimension.

Effect of casting atmosphere on the shear bond strength of a ceramic to Ni-Cr and Ni-Cr-Be alloys.

The success of metal-ceramic restorations depends on an optimal bond between metal and ceramic. This study evaluated the effect of 3 casting atmospheres on the metal-ceramic bond strength (MCBS) of 2 Ni-Cr alloys, with beryllium (Fit Cast V) and without beryllium (Fit Cast SB). Sixty acrylic resin patterns (8 mm long and 5 mm diameter) were obtained using a fluorocarbon resin matrix.

Use of resin-bonded extracoronal attachments with removable partial denture: case report.

Introduction: Resin-bonded extracoronal attachments may be indicated for the abutment teeth of removable partial dentures, especially for anterior teeth when a cingulum rest must be provided. This type of treatment has a series of advantages such as minimal tooth reduction, supragingival margins, favourable stress distribution, and improved aesthetic appearance.

Objective: To report a clinical case of oral rehabilitation using a combination of resin-bonded extracoronal attachments joined by a Dolder bar with a removable partial denture.

Comparative study of intermaxillary relationships of manual and swallowing methods.

This study compared the mandibular displacement from three methods of centric relation record using an anterior jig associated with (A) chin point guidance, (B) swallowing (control group) and (C) bimanual manipulation. Ten patients aged 25-39 years were selected if they met the following inclusion criteria: complete dentition (up to the second molars), Angle class I and absence of signs and symptoms of temporomandibular disorders and diagnostic casts showing stability in the maximum intercuspation (MI) position. Impressions of maxillary and mandibular arches were made with an irreversible hydrocolloid impression material.

Correlation between metal-ceramic bond strength and coefficient of linear thermal expansion difference.

The purpose of this study was to evaluate the metal-ceramic bond strength (MCBS) of 6 metal-ceramic pairs (2 Ni-Cr alloys and 1 Pd-Ag alloy with 2 dental ceramics) and correlate the MCBS values with the differences between the coefficients of linear thermal expansion (CTEs) of the metals and ceramics. Verabond (VB) Ni-Cr-Be alloy, Verabond II (VB2), Ni-Cr alloy, Pors-on 4 (P), Pd-Ag alloy, and IPS (I) and Duceram (D) ceramics were used for the MCBS test and dilatometric test. Forty-eight ceramic rings were built around metallic rods (3.

T-bar clasp-retained removable partial denture as an alternative to implant-based prosthetic treatment.

This article reports the case of a 55-year-old female patient who presented with unsatisfactory temporary crowns in the right mandibular premolars and molars, and a premolar-to-molar fixed partial denture in the left side. The clinical and radiographic examinations revealed a fracture of the left first premolar that was a retainer of the fixed partial denture and required extraction. Initially, the acrylic resin crowns were replaced by new ones, and a provisional RPD was made using acrylic resin and orthodontic wire clasps to resolve the problem arising from the loss of the fixed partial denture.

Effect of the use of die spacer on the marginal fit of copings cast in NiCr, NiCrBe and commercially pure titanium.

The goal of this study was to evaluate the effect of using die spacers on the marginal fit of NiCr (M1) and NiCrBe (M2) alloys and commercially pure titanium (cpTi) (M3) copings cast by the lost wax technique. Using a metal matrix, 45 resin added extra hard type IV stone models were obtained for the fabrication of wax patterns under the following conditions: no die spacer (A), with one die spacer layer (B) and with two die spacer layers (C), with five repetitions for each condition (alloy x die). Each die was waxed and the wax patterns were invested as per manufacturer's instructions.

The castability of pure titanium compared with Ni-Cr and Ni-Cr-Be alloys.

Statement Of Problem: Titanium is the most biocompatible metal available for dental casting; however, there is great concern about its castability since this aspect of a casting metal/alloy has direct influence on the marginal fit of dental crowns.

Purpose: The purpose of this study was to compare the castability of commercially pure titanium with 2 Ni-Cr base metal alloys.

Material And Methods: Castability was evaluated indirectly by determining the sharpness of cast crown margins using the lost-wax technique.

Clinical evaluation of interocclusal recording materials in bilateral free end cases.

Five combinations of materials commonly used for intermaxillary records in cases of bilateral free end saddle were evaluated: acrylic resin base + wax; acrylic resin base + wax + ZOE paste; acrylic resin base + wax + Duralay resin; condensation silicone; and acrylic resin plate + irreversible hydrocolloid. The materials were evaluated by measuring the vertical distance between pairs of reference points located on the bases of the upper and lower articulated casts. The measurements obtained by manual articulation of the casts were used as the standards to which the measurements obtained with the recording materials were compared.

Influence of investment type and sprue number on the casting accuracy of titanium crown margins.

Statement Of Problem: Titanium offers biocompatibility and adequate mechanical properties for fabricating dental prostheses; however, casting difficulties can compromise the accuracy of titanium crown margins.

Purpose: The aim of this study was to evaluate the influence of investment type and number of sprues on accuracy of crown castings made with commercially pure titanium.

Material And Methods: The casting accuracy was evaluated indirectly by determining the deficiency of titanium crown margins cast using the lost-wax technique.

Effect of casting technique on surface roughness and consequent mass loss after polishing of NiCr and CoCr base metal alloys: a comparative study with titanium.

Statement Of Problem: Surface roughness of cast metal frameworks may lead to difficulties in finishing or polishing procedures and weaken the framework.

Purpose: The aim of this study was to assess the surface roughness of 2 base metal alloys, submitted to different casting techniques, to determine the influence of surface roughness on loss of mass after polishing compared to commercially pure titanium castings.

Material And Methods: Forty disk-shaped wax patterns (8 x 2 mm) were randomly assigned to 5 groups (n=8): (1) CoCr alloy (Wironit), acetylene-oxygen flame casting (WFC), (2) NiCr alloy (Verabond II), acetylene-oxygen flame casting (VFC), (3) CoCr alloy, vacuum casting (WVC), (4) NiCr alloy, vacuum casting (VVC), and (5) commercially pure Ti alloy (Ti) melted by electric arc in argon gas atmosphere.

Combination therapies in the treatment of temporomandibular disorders: a clinical report.

Numerous implant systems exist that have the versatility to create a custom implant abutment with an anatomic shape. This clinical report describes the use of a digital scanner with CAD/CAM technology to create (copy mill) an anatomically shaped abutment.

Comparative study of circumferential clasp retention force for titanium and cobalt-chromium removable partial dentures.

Statement Of Problem: The interest in using titanium to fabricate removable partial denture (RPD) frameworks has increased, but there are few studies to support its use.

Purpose: The objective of this study was to compare circumferential RPD clasps made of commercially pure titanium and identical clasps made of 2 different cobalt (Co)-chromium (Cr) alloys by testing insertion/removal and radiographically inspecting the casts for defects.

Material And Methods: On refractory casts that represent a partially edentulous mandibular right hemi-arch segment, 36 frameworks were cast from commercially pure titanium (n = 12) and 2 Co-Cr alloys (n = 12 each) with identical prefabricated patterns and the manufacturer-designated investment and casting technique.