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Biomedical subjects

R A Feinman

Publications and source records attributed to R A Feinman.

At least 19 recordsLinked to original sources
PubMed1997

A combination porcelain/fiber-reinforced composite bridge: a case report.

In the search for an optimal treatment to restore the aesthetically prominent maxillary anterior dentition, new materials are continually introduced. The attention of the patients has shifted from function to aesthetics, biocompatibility of the materials utilized, and conservative preparation of teeth to be restored. To fulfill patient expectations, an advanced treatment modality has recently been developed. It combines porcelain with composite resin, thereby integrating the strength and resilience of composite resin with the aesthetic advantages of porcelain. To achieve this combination, bundles of fibers are impregnated with resin in the fabrication phase of the material. The learning objective of this article is to briefly review the past methods of fabricating a 3-unit prosthesis in the maxillary anterior region and describe the recently introduced treatment alternative.

Adolescent↗
PubMed1995

High velocity air microabrasion for conservative tooth preparation: the principle and the clinical procedure.

Various technologies within the dental armamentarium are applied to achieve the precise tooth preparations required for the different types of restorations. This article reintroduces the air microabrasion technique, which was first presented in 1945. The popular use of this technique had been postponed, pending the decrease in cost and development of compatible restorative materials to repair the tooth structure. With increased patient demand for less invasive preparation techniques and the decrease of the equipment cost, the use of air microbrasion for tooth preparation has been recognized. The history of the technology, its function, indications, advantages, and limitations are discussed, and a step-by-step clinical procedure is presented. The learning objective of this article is to familiarize the readers with this preparation procedure, enhancing the knowledge of preparation options.

Air Pressure↗
PubMed1994

Bleaching vital teeth.

This year is approximately the fifth year of controlled bleaching of vital teeth administered by the patient, and this practice still generates a great deal of discussion by the American Dental Association, the US Food and Drug Administration, the media, and general practitioners. The placement of a plastic carrier intraorally to hold a carbamide peroxide gel in the mouth is referred to as passive bleaching or dentist-prescribed home bleaching. This article reviews the past year's research, which contains many opposing opinions in both in vitro and in vivo studies with respect to the effect of carbamide peroxide on the hard and soft tissues when they come into contact with this agent for various lengths of time. Above all, the question of safety still arises, although few if any adverse effects have been reported with the use of dentist-prescribed, patient-applied home bleaching. Five years of nonproblematic treatment for millions of patients leads many dentists to believe that this technique, when controlled by the dentist, serves the public well.

Carbamide Peroxide↗
PubMed1993

Class II direct composite resin restorations using the prepolymerized ball technique.

The use of composite resin restoration materials and techniques has advanced steadily since the early 1980s, with innovations and improvements in products and application procedures. This article discusses one of the most up-to-date composite resin restoration materials and the technique of placing a prepolymerized resin ball into an appropriately prepared cavity, thereby maintaining contact and contour of the restoration.

Bicuspid↗
PubMed1988

Signaled avoidance in the eye withdrawal reflex of the green crab.

Learning in a signaled avoidance procedure was studied in the eye withdrawal reflex of the green crab, Carcinus maenas. A puff of air to the eye, which causes eye retraction, was used as the unconditioned stimulus (US). A mild vibration on the carapace, which has no effect on untrained animals, was used as a warning (conditioned) stimulus (CS). Eye withdrawal during the CS led to the omission of the otherwise scheduled US. Acquisition was rapid, reaching about 75% avoidance after 30 trials. Extinction occurred slowly over the course of 40 CS-only trials. Yoked controls did not perform as well. The behavior of experimental animals in the avoidance procedure was found to be essentially identical to the performance of animals subjected to a classical conditioning paradigm in which CS responses had no effect on US presentation. Additional groups of animals were subjected to experiments in which (a) avoidance conditioning (60 trials) was followed by classical conditioning (40 trials) or (b) classical conditioning was followed by avoidance. The behavior of these groups was, again, essentially identical. The results suggest that there may be an underlying Pavlovian mechanism for the learned response, although the contribution of an operant process is not excluded. The results expand the range of invertebrate animals in which fundamental conditioning phenomena can be demonstrated, and may provide a neuronal model for learning in a signaled avoidance procedure.

Journal Article↗