Gerald T. Charbeneau

Profile Characteristics of Cut Tooth Surfaces Developed by Rotating Instruments

THE irregularity of the cut tooth surfaces resulting from the shaping of cavities would appear to have a twofold significance. First, these irregularies should have some effect on the adaptation of the specified filling material to the cavity walls, and second, they may tend to undermine or weaken groups of enamel rods at the eavo-surface margins, thus resulting in a failure of the tooth structure surrounding the restoration rather than a failure of the restoration itself. In order to determine the significance that these irregularities may have in either case, it is desirable to know their magnitude as produced by various instruments. Appraisals of such surface roughness have been made previously by Street,6 and Peyton and Mortell.5 These methods of evaluation have been somewhat qualitative since they rely on observation at right angles to a cut surface which has been previously treated to make the crests of the irregularities more distinguishable. The eye is, however, more sensitive to the spacing of the irregularities rather than their height.2 Lammie4 used a stylus-type surface analyzer which gives an average height rating for a given surface. Such recordings do not provide a profile of widely spaced irregularities. Therefore, the Proficorder, an instrument of different design, has been employed in this study.

The gingival response to well-finished composite resin restorations.

Within the limits of this study, the following conclusions are made: 1. Well-finished and contoured composite resin restorations do not adversely affect the health of the gingiva. 2. The gingiva exhibits less inflammatory response to a well-finished and contoured composite resin restoration than to an open carious lesion. 3. The gingival inflammatory changes which do occur are independent of the presence of well-finished and contoured composite resin restorations. 4. Observation over an extended period of time is necessary to determine if composite resin restorations ultimately become gingival irritants.

Tissue response to an electric pulp tester.

1 he electric pulp tester used to determine tooth vitality has served dentistry since 1867 when it was introduced by Magitot. 1 It remains one of the most useful means of clinically differentiating between vital and nonvital teeth.2 Successful use depends upon an electrical impulse traversing mineralized dental tissues to stimulate pulpal nerves. Despite widespread use of the tester, little is known about the constancy of pulpal sensitivity at different times or under different conditions. Also, it has been stated that prolonged “stimulation at high intensities causes irreversible damage to the tooth.“3 Whether electric pulp testers currently in use are capable of producing irreversible pulp damage is not known. The purpose of this study was to determine whether they are capable of producing morphologic alteration of pulpal tissue.

Gingival tissue response to restoration of deficient cervical contours using a glass-ionomer material. A 12-month report

M any dental restorative materials are placed into contact with the contiguous gingival tissues. Testing biologic responses to these materials is imperative for providing successful dental treatment to patients. Cervical tooth tissue deficiencies are a part of the many pathologic entities that affect the natural dentition.’ Different authors have postulated theories trying to explain the etiologic factors of these lesions.2-5 Incorrect tooth brushing, oral habits performed with foreign objects, dietary elements, and even soft tissue action have been related as causative factors for cervical dental lesions to appear.6-7 These cervical abrasions and/or erosions are widely treated with conservative Class V restorations, many of which are in contact with the gingiva. Of all the restorative materials available, composite resin and amalgam are more widely used to treat cervical cavities. Recently, a new type of restorative material, glass-ionomer cement, has been developed. It is essentially an aluminosilicate polyacrylate cement. Recommended for use where cervical anatomic deficiencies exist, it has been suggested that there is no need of cavity instrumentation for placement in teeth with cervical V-shaped lesions without caries.8 Uor saucer-shaped lesions must contain a definitive finishing line. At present, there are no data regarding soft tissue responses to this restorative material nor to the value of the restorative procedure with regard to gingival

Quantitative evaluation of proximal tooth movement effected by wedging: A pilot study

The major purpose of this pilot study was to develop a method to accurately measure proximal tooth movement. A preliminary clinical evaluation of anterior and posterior tooth movement was performed with five patients. The patients were carefully chosen to eliminate as many variables as possible. The controlled patient criteria included periodontal health, proximal contacts, the age of the patients, and the teeth selected for anterior and posterior displacement. The small sample size dictates that additional experimentation must be performed before definitive conclusions can be drawn.

In vivo Remineralization Using a Sustained Topical Fluoride Delivery System

The efficacy of a new remineralization system was determined in vivo by maintaining a low concentration of approximately 1 ppm fluoride for 48 hrs against a demineralized human tooth. Human subjects were selected who wore removable partial dentures containing two or more of the demineralized teeth with film system. The findings indicate levels of fluoride uptake to 500 ppm at 50 micron depths in experimental sites.

Surface roughness of two dental amalgams after various polishing techniques

1. In comparison with standard polishing after 24 hours, no advantage is gained by using an abrasive paste after 10 minutes. Polishing after 24 hours produced a significantly smoother surface for both amalgam alloys on both the simulated proximal and occlusal surfaces. 2. The standard polishing procedures after 24 hours produced a smoother surface than any of the immediate finishing procedures tested. 3. The high-copper amalgam was signijficantly rougher with initial carving and immediate finishing, but surfaces of both alloys were equally smooth when polished after 24 hours. 4. Both amalgam alloys, when condensed against a new matrix band lacked smoothness when compared to the surfaces obtained by finishing after 24 hours. 5. There was a high correlation between arithmetic average roughness and average maximum peak height as quantitative measurements of surface texture.

Quality assessment of amalgam and inlay restorations on posterior teeth: a retrospective study.

This study was designed to assess and compare the quality of posterior proximo-occlusal amalgam and inlay restorations relative to type of restoration (material, surfaces involved, and cusp protection) and length of service of the restorations. A clinical evaluation system based on operationally defined and clinically important criteria was used. Clinically and statistically significant differences were found between overall ratings for amalgam and inlay restorations and between small (two-surface) amalgam and inlay restorations, as well as between larger (three-surface) amalgam and inlay restorations. In all cases, inlay restorations were of higher quality. A not acceptable rating for marginal integrity was the most frequent reason for not acceptable overall ratings. There was no difference in satisfactory/not acceptable ratings for inlay restorations with or without protected cusps (p = .95).