Abrasive Instrument Research Articles

Gingival reaction to well-fitted subgingival proximal gold inlays.

Abstract Proximal inlays were seated in contralateral teeth in eight subjects with clinically healthy gingivae. After 23 days, the subgingival area and part of the supragingival surface of one of the inlays was roughened with an abrasive instrument up to 1 mm above the gingival margin; the other inlay remained polished. Gingival fluid flow rate was buccally and lingually measured in the papillary area close to the proximal roughened and polished inlay surfaces and also at papillae beside sound proximal surfaces of the same teeth during a period of 85 days. In addition, plaque was scored and also assessed planimetrically.The mean gingival fluid flow rate was significantly higher adjacent to both the rough and polished filling surfaces when compared with proximal surfaces without restoration. Plaque indices were similar in the vicinity of filled and sound proximal areas irrespective of the gold surface texture. Planimetrically more plaque was formed on the sites of roughened inlays.

Dermal changes following abrasion.

The purpose of this paper is to report histologic and clinical observations at intervals up to four years, following both therapeutic and experimental abrasion of the skin. Material and Methods Thirteen patients from the Dermatology Service (Surgical Skin Planing Clinic) of the Los Angeles County General Hospital and from the private practice of one of us (S. A.) were utilized in this study. Some were relatively young, with acne scars of the face (the biopsy specimens included skin<i>not</i>acne scarred, however), while the majority were in the 70- to 80-year age bracket with multiple recurrent actinic keratoses of the face (farmers' or sailors' skin). In the case of two men whose backs were utilized for quantitative studies, the skin was normal senile skin. The abrasions were performed with a motordriven rotating abrasive instrument. A steel wire brush¹⁸was used on the earlier patients and

Modern Rotating Instruments—Burs and Diamond Points

Removal of tooth structure by mechanical instrumentation employing burs and abrasive wheels and points, when utilizing the conventional dental handpiece, is ineffective, traumatic and fatiguing. It is apparent that more efficient operating procedures are possible as a result of the development of rotating cutting instruments of improved design and composition and handpieces capable of speeds in excess of 200,000 rpm. The use of diamond instruments, carbide burs and ultra high speeds provides a more effective method for the rapid removal of hard tooth structures. Through the application of these modern instruments, employing very light pressures and the continuous use of coolants, there is a significant reduction in trauma incident to operative procedures. These are important factors in relieving nervous tension for both the patient and the operator. The vibrations produced by ultra high speed cutting lie in a range of frequencies which approach the upper limit of perception. As a result the sensations produced are less unpleasant than those stimulated by the lower speeds and heavy pressures usually employed. In the final analysis, success in the clinical application of modern instruments is dependent upon the operator’s knowledge of the many physiologic and mechanical principles involved. These technics and procedures may change, to some degree, the present concepts of procedures in the removal of tooth structure, but they do not change the basic and sound principles of classic cavity preparation. Further improvements in dental handpieces will continue. Speeds that are now considered relatively high may be considered moderate if present trends continue. The design of burs and diamond abrasive instruments in many cases requires improvement. Such factors as the optimum size of the diamond abrasive particles for the ultra high speeds have not been resolved. Bur blade designs which have not changed for half a century may be improved. Perhaps a type of rotary file may lend itself efficiently to ultra high speed cutting. The changes in rotary operating equipment have been so rapid in the past few years that both the profession and the dental industry have been hard pressed to keep abreast of this progress. There is little doubt that the improved devices currently available to the profession have already contributed very significantly toward reducing patient discomfort and operator fatigue, and have increased operating efficiency to a marked degree.