Biomedical subjects

M E Essig

Publications and source records attributed to M E Essig.

4 recordsLinked to original sources

PubMed1999

A new technique for generating a computer-aided design and computer-integrated machining crown: case report.

A new technique for producing a Computer-Aided Design and Computer-Integrated Machining Ceramic Reconstruction crown is presented. After completion of the tooth preparation, an "optical" impression of the tooth was made with a charged couple device camera, and the electronic image was transferred to a computer screen. The "proposed" crown was electronically designed on the screen by the operator, and a proper prefabricated ceramic block was selected and used as milling material. A miniature milling machine then fabricated the crown from the ceramic block. The marginal adaptation and the contour of the crown were verified, and an external shading technique was utilized to improve the esthetics. The prepared tooth and crown were acid-etched, and the crown was cemented with a dual-curing composite luting agent. Once bonded in place, the occlusion was adjusted and the crown polished and finished. The advantage of this technique is that it eliminates the traditional laboratory casting procedure and corresponding laboratory fee while utilizing materials with superior physical properties for maximum strength and esthetics.

Adult↗

PubMed1989

A new method for generating ceramic restorations: a CAD-CAM system.

The CAD-CAM CEREC system is a small, complex unit developed for electronically designing and milling ceramic restorations. The system makes it possible to generate a restoration without taking impressions, developing temporary prostheses, and without laboratory assistance. The entire restorative procedure is performed in one appointment. Basic features include the following: the cavity preparation is scanned stereo-photogrammetrically, using a three-dimensional miniature video camera; the small microprocessor unit stores the three-dimensional pattern depicted on the screen; the video display serves as a format for the necessary manual construction via an electrical signal; the microprocessor develops the final three-dimensional restoration from the two-dimensional construction; the processing unit automatically deletes data beyond the margins of the preparation; the electronic information is transferred numerically to the miniature three-axis milling device; driven by a water turbine unit, the milling device generates a precision-fitting restoration from a standard ceramic block; the entire process of electronic designing and subsequent milling of a ceramic restoration requires approximately 10 to 15 minutes.

Computer Simulation↗

PubMed1985

Enamel microhardness change and plaque pH measurements in an intra-oral model in humans.

Changes in plaque pH and microhardness of bovine enamel slabs were evaluated with a seven-day intra-oral cariogenicity test (ICT). The test enamel slabs were mounted in prosthetic appliances with a Dacron mesh cover for enhancement of microbial colonization. Three percent solutions of sucrose, sorbitol, and xylitol were evaluated as four daily extra-oral immersions of 10 min each, for seven days, and the results were compared with baseline experiments (no daily immersions). The pH was measured with antimony electrodes on one-day and seven-day ICT plaque samples that were challenged with a one-minute immersion in the studied substrates. Plaque samples in the baseline experiments were challenged with 3% sucrose. The enamel softening was assessed with measurements of microhardness. Sucrose challenge caused pH depression with both the baseline and the sucrose-immersed plaque. Sorbitol and xylitol challenge did not depress the plaque pH. Compared with the baseline, sucrose immersions caused enamel softening; sorbitol and xylitol did not.

Animals↗

PubMedDate not supplied

Three-year clinical evaluation of CAD/CAM restorations.

This study dealt with the clinical evaluation of 121 inlays and onlays generated from both Dicor ceramics and Vita porcelains. These two different types of ceramic materials were cemented using three different duo-cured composite resin luting agents, which differed in particle size. At the end of 3 years, no difference could be detected between the clinical performance of the Dicor and Vita restorations. Both exhibited the same degree of color matching characteristics, marginal integrity, and general clinical performance; however, seven of the restorations exhibited fracture through the isthmus, which was shown to be due to insufficient cavity depth. The balance of the restorations exhibited excellent clinical performance when evaluated against the United States Public Health Service System.

Aluminum Oxide↗