PURPOSE The aim of this study was to evaluate the effects of repeated porcelain firing process on the corrosion rates of the dental alloys. MATERIALS AND METHODS Cr-Co, Cr-Ni and Pd-Ag alloys were used for this study. Each metal supported porcelain consisted of 30 specimens of 10 for 7, 9 and 11 firing each. Disc-shaped specimens 10 mm diameter and 3 mm thickness were formed by melting alloys...

Dentists and technicians have used dental ceramics associated with different types of alloys without taking into account the characteristics of compatibility of these materials. Knowing the properties of the alloy and ceramic used in metal/ceramic restorations is a key factor for treatment success. The purpose of this study was to evaluate the bond strength of a palladium-silver alloy (Pors-on ...

The electrochemical behaviors of eight parent alloys and four post-solder alloys used in dental prostheses were specified in a (pH=7.4; [NaCl]=9g/L)-aqueous solution at 37°C. For each alloy, the free potential was followed during two hours, and a cyclic polarization between the cathodic domain and the solvent’s oxidation was performed. The galvanic corrosion between each parent alloy and its us...

Five non-precious Ni-Co based alloys were analyzed with respect to their corrosion behaviour. The correlation between the amount of the elements Cr, Mo, V and the corrosion behaviour, expressed by the PREN (pitting resistance equivalent number) index in the case of the allied steels, was extended for Ni-Cr and Co-Cr dental alloys characterization. Open circuit potential, corrosion current densi...

s of the 9th Congress of Japan Bi-Digital O-Ring Test Medical Society July 24-25, 1999 Sanjyo Kaikan, Tokyo University, Tokyo Japan I. Dental Presentation Relationship between the Onset of Pustulosis Palmaris et Plantaris, Metal Allergy, and Chronic Oral Infectious Diseases Munehiro Kosugi, D.D.S. Research Fellow of Department of Microbiology, Tokyo Dental College; Funabashi City Bi-Digital O-R...

Numerous studies have been done in the past to identify the phases present in dental amalgam. Both metallographic and X-ray diffraction techniques have been used.-' Most researchers now presume that dental amalgam consists mainly of three phases. The original particle is an alloy of Ag, Sn, Cu, and sometimes Zn; the major portion is the compound Ag3Sn, which is often referred to as Py. After am...

Disintegrating the adhesive bridge from the abutment is one of the most uncomfortable consequences for the patient, and especially for the therapeutist, as it arises a question on the justifiability of the applied method. The success of these appliances depends on the design of the metal skelet, the strenght of the cement itself, as well as its bonding with the etched enamel and the dental allo...

STATEMENT OF PROBLEM For some patients, radiation treatment is a part of tumor therapy in the head and neck area before and/or after surgery. The oral cavity and teeth are thereby frequently exposed to high doses of radiation. In this situation, electronic backscatter from dental materials may damage the surrounding soft tissue. PURPOSE This study determined the degree of absorption and the b...

A preceding study of contact damage in a bilayer system consisting of a porcelain coating on a stiff Pd-alloy substrate is here expanded to investigate the role of substrate modulus and hardness. Bilayers are made by fusing the same dental porcelain onto Co-, Pd-, and Au-alloy metal bases. Indentations are made on the porcelain surfaces using spheres of radii 2.38 and 3.98 mm. Critical loads to...

The mechanical properties of six 35Ag-30Pd-20Au-15Cu alloys containing different contents (2% and 4%) of Sn, Ga, or In and a 35Ag-30Pd-20Au-15Cu alloy without additives were evaluated. These alloys were subjected to four different heat treatments before a mechanical test. The distribution of the elements and their contents were analyzed. The mechanical properties of 35Ag-30Pd-20Au-15Cu alloy ch...