Article: Scanning electron microscope study for axial and marginal fitness of three different ceramometal alloys.[show abstract] [hide abstract]
ABSTRACT: In this study the SEM was used to measure the axial and marginal gap distance and to declare the marginal openings and faulty castings of three different ceramometal alloys a precious, semi-precious and nonprecious alloy systems that are commercially used in crown and bridge prosthodontics and to make a comparison between them in regard to axial and marginal gap distance.Egyptian dental journal 10/1995; 41(4):1417-22.
Article: The effect of the type and technique used for impression making on the accuracy of elastomeric impression materials.A N Habib, M T Shehata[show abstract] [hide abstract]
ABSTRACT: The effect of the technique used for impression making on the accuracy of three types impression materials, (vinyl silicons, condensation silicons and polyether elastomers) was evaluated. Three main impression making techniques were used. Impressions were made for stainless steel master model. The impressions were poured after thirty minutes with improved stone into stone casts. Accuracy was assessed by comparing seven measurements of the master model to their corresponding on the stone case produced. A travelling microscope of 0.001 mm accuracy was used for measurements. The results of the study have shown that all elastomeric impression materials produced accurate impression but with significant difference among them. The polyether was more accurate than silicon impressions. The technique used for making the impression had more effect on the relative accuracy than the type of the material. Reference for the best technique for each type was concluded.Egyptian dental journal 10/1995; 41(4):1409-16.
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ABSTRACT: A chemical etching technique is described for producing etch patterns in beryllium-free nickel chromium ceramo-metal alloy. Disc-shaped samples were chemically etched, evaluated with SEM and analysed by the EDAX technique. Scanning electron micrographs revealed, profound retentive cavities. The EDAX analysis provided a comprehensive interpretation of the etch mechanism. The obtained results show that the developed chemical etching has the potential to produce a highly retentive etched surface with less problematic and less technique sensitive than electrolytic etching.Egyptian dental journal 10/1995; 41(4):1391-5.
Article: Effect of application of ultrasonic vibrations on the cement bond strength of cemented cast crowns.Egyptian dental journal 08/1994; 40(3):833-8.