Harry Blechman

Bacterial Invasion of Pulpal Dentin Wall in vitro

Instrumented root canals of extracted human teeth were inoculated with known pulpal bacterial isolates. The inoculated teeth were immersed in the appropriate culture media and incubated at 37° C for varying periods. Streptococci multiplied in the root canals and invaded the radicular dentinal tubules. The extent of bacterial invasion was time-dependent. This experimental model may be useful in investigating the effect of intra-canal medicaments on microorganisms lodged in the pulpal dentin wall.

Periapical actinomycosis: An unusual case report

An unusual case of actinomycosis in the oral cavity is reported. The strict anaerobic qualities of Actinomyces israelii make laboratory culturing and growing of this organism difficult. Accordingly, the diagnosis was based on the histopathologic report. Because of the atypical clinical presentation, i.e., lack of any discharging sinus tract on the skin surface, and the histopathologic reports, it was postulated that the actinomycosis was superimposed on an existing granulomatous tissue.

Survey of the Yeast Population in Saliva and an Evaluation of Some Procedures for Identification of Candida albicans

A number of investigators during the last 25 years have reported on the frequency and distribution of yeasts and yeastlike organisms in the oral cavities and throats of apparently normal individuals and those with systemic or mycotic disease.12 For a comprehensive review of the literature prior to 1939, the reader is referred to a paper by Knighton.2 During the past decade, a number of selective enrichment and differential media have been introduced for the isolation and identification of yeasts and yeastlike micro-organisms. It was the purpose of this study to apply a number of the newer procedures to a survey of the yeast populations of the oral cavity.

A study of some factors associated with endodontic “flare-ups”

A study was undertaken by the TS others were broken during transit, as a result of improper packing; and in some instances x-ray films were not submitted. Thus, in the accompanying tables the total numbers of cases in various categories are not identical.

Primary herpes simplex virus infection in an adult.

Abstract A case of primary inoculation of a dental students fingers with herpes simplex virus has been reported. The infection in this case resulted from exposure to a patient with recurrent herpes labialis. The need for recognizing this hazard in dental practice has been discussed and the criteria for the diagnosis have been defined.

Production of Levan and Dextran in Plaque In Vivo

Frequent eating of small amounts of sucrose for a period of three days resulted in the in vivo accumulation in plaque of about 1% dextran and about 3% levan.

The effect of varying particle size of the components of Grossman's cement.

Uniform mixtures of Grossmans New Formula Root Canal Cement of differing particle size were prepared and compared for physical differences. The mixes composed of smaller particles gave denser, more radiopaque, quicker setting and were more homogeneous than the mixes with larger particles.

Effectiveness of Disposable Face Masks in Preventing Cross Contamination during Dental Procedures

Aerosols generated by the air turbine handpiece contain oral microorganisms that are a potential health hazard to the dentist. The effectiveness of different face masks in preventing cross contamination varied greatly but in all instances was significant.

The effects of desalivation on periodontal tissues of the Syrian hamster

Abstract Sixty hamsters were used to study the effects of desalivation on the incidence of periodontal lesions under three different dietary regimens. The desalivated animals consistently showed a greater number and extent of periodontal lesions in the soft and calcified tissues than their controls. Highly statistically significant differences were observed between the lesions of the control animals and those of the desalivated animals. The consistency and composition of diet seemed to play a role in the production of periodontal lesions in the hamster. High-carbohydrate, finely powdered, cariogenic ration 4 produced a greater number and extent of soft-and calcified-tissue lesions than either the laboratory chow or the ground laboratory chow. Ground laboratory chow produced a greater number and extent of lesions than laboratory chow in pellet form. The effects of the diets on the soft tissues appeared to be more severe than on the calicified tissues. The microscopic findings substantiated the gross observations. The desalivated animals showed histologic changes of greater severity than the intact controls. The pronounced changes in the desalivated animals were apical migration of the epithelial attachment and the presence of epithelium at the interradicular area. The control and desalivated animals fed ration 4 showed severe osteoporosis, possibly due to the nutritional inadequacy of the diet.

ANTIGENIC SUBSTANCES IN SOUND AND CARIOUS DENTIN

One of the more intriguing problems in caries research considers the role of immunological mechanisms in the initiation and progression of the carious lesion. The finding of gamma globulin (Ellison et al., 1960; Mandel and Ellison, 1961; Kraus and Sirisinha, 1962; Leach et al., 1963) and antibodies in oral fluids against a number of indigenous oral micro-organisms (Kraus and Konno, 1963) suggests the hypothesis that saliva may play an important role in modifying the carious process. In addition, others have shown that serum fractions may reach the ground substance of connective tissue, skin (Humphrey et al., 1957) and gingiva (Zwemer et al., 1959). Similar fractions could conceivably reach dentin by way of pulpal and periodontal tissues and provide another barrier. In view of these observations it occurred to us that an immunologic approach might yield additional information on aspects of the pathogenesis of dental canes. It was the intent of this investigation first to determine the antigenicity of human sound and carious dentin and then to characterize wherein possible the nature of some of the antigenic substances found therein. In this paper, we are reporting our procedures and some preliminary observations on the wide variety of substances which appear to be present in sound and carious dentin.