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Biomedical subjects

M M Stark

Publications and source records attributed to M M Stark.

13 recordsLinked to original sources

Evaluation of the apical sealing ability of apatite root canal sealer.

The apical sealing ability of a tricalcium phosphate sealer was compared with that of three other sealers. Seventy roots of human incisors were cleansed and shaped and randomly assigned to one of seven groups of ten roots each. The root canal systems were obturated with gutta-percha and one sealer using the lateral-vertical condensation technique. The canal was sealed with Roth's sealer, Sealapex, Kerr root canal sealer, or Sankin apatite root sealer (Type I, II, or III). One group was filled with gutta-percha without sealer to serve as a control. After the roots were immersed in silver nitrate, the degree of dye penetration was measured under a dissecting microscope. Results indicated that Sealapex had the best sealing ability, followed by Sankin apatite root sealer, Type II. Roth's cement showed the most dye penetration. Canals that were obturated without sealer showed significantly greater apical leakage.

Apatites

Human blood pressure and pulse rate response to racemic epinephrine retraction cord.

1. The pulse rate of patients after application of racemic epinephrine-impregnated retraction cords depends more on the level of anxiety and stress than on the level of the epinephrine. 2. Blood pressure is elevated by placement of racemic epinephrine-impregnated retraction cords upon an exposed vascular bed or lacerated tissue. 3. Four percent racemic epinephrine-impregnated retraction cords cause less elevation of blood pressure than 8% racemic epinephrine cords. 4. Although the elevations in blood pressure from 8% cord occur within a narrow range, this range may be hazardous to cardiac patients. Therefore, 4% racemic epinephrine cord should be used. 5. A desirable amount of tissue retraction is produced by 4% racemic epinephrine cord. 6. Dry cords do not provide adequate retraction of tissue and are contraindicated for tissue-retraction purposes.

Adult

Rationalization of electric pulp-testing methods.

A new electric pulp-testing system, the Testark, was developed in order to assess the potential of a different way of testing pulp sensitivity, thus making this electric pulp test more dependable than the conventional electric pulp-testing method. A study was conducted to evaluate the potential of the Testark system in comparison with a commercially available pulp tester. This pilot study consisted of application of three different desensitizing agents (sodium fluoride, test product. 'A', and test product 'B') to the cervical areas of hypersensitive teeth. The results were recorded with both the Testark and the conventional pulp tester simultaneously, and the sodium fluoride and test product 'B' proved to yield a beneficial effect by desensitizing the teeth after a single application. The level of desensitization with these agents was higher than the level obtained with the test product 'A' paste, which was utilized daily for 14 days. The results obtained with the conventional pulp tester differed by way of interpretation from those obtained with the Testark system. The Testark system proved to be easy to use and highly accurate in the data readings because of its high resolution. The Testark systemwas found to be more dependable than the commerical pulp tester, since it reduced the subjective errors which are inevitable when a commerical pulp tester is used. The Testark system is being developed further, and more studies are being conducted at the present time, in order to assess the full potential of the instrument.

Adult

Laser evaluation of handpiece contamination.

Six different models of ultra-high speed handpieces were evaluated in regard to debris accumulation following cutting through tooth structure. A weight-load machine and a laser particle detector were utilized to evaluate the amount of the debris retained. Amounts of debris accumulated after dry and wet cutting were also evaluated. The effect of simple wiping of the handpieces with alcohol guaze was assessed. The results obtained show that the longer the cutting time, the larger the amounts of debris retained on the handpieces. Dry cutting resulted in smaller amounts of debris entrapped than following wet cutting. The cleaning by wiping with alcohol gauze reduced the amounts of the debris, but is insufficient and cannot be utilized as a single procedure for decontaminating handpieces. The external head design is a cardinal factor in retention of debris: larger but smoother surfaces will retain less debris than smaller but more complicated surfaces. External tubings are debris retention foci.

Clinical Trials as Topic

Direct and indirect pulp capping.

Cavity disinfection, indirect pulp capping, and direct pulp capping have been discussed in light of present day knowledge of the biology of the pulp. A format has been presented to the restorative dentist which has had long-standing clinical acceptance based on some scientific data and clinical evidence to substantiate the treatment radionale.

Calcium Hydroxide

Comparison of tissue response between a synthetic gutta-percha and a natural gutta-percha endodontic filler.

Biologic acceptance is one of several criteria that must be met by an endodontic filling material. The purpose fo this experiment was to compare a new filling material consisting of a synthetic gutta-percha with a standard material consisting of natural gutta-percha. Each sample, being an endodontic point, contained a quantity of fillers. The materials were implanted subcutaneously in male white rats. The histologic appearance was essentially identical for both materials.

Animals