Faculty Bibliography

The quantitation of catecholamines has yet to be reported in the human dental pulp. Various methods of chemical detection have shown the presence of catecholamines in pulpal tissue. Pulpal tissue was obtained from nonrestored, uninflamed teeth that needed to be extracted. The samples were collected, extracted, and analyzed by means of high-performance liquid chromatography with ultraviolet detection for levels of catecholamines (dopamine, epinephrine, and norepinephrine). As mediators of vasoconstriction, catecholamines play an important role in the control of intrapulpal pressure. This research describes a method for quantitation of catecholamines. Future studies investigating inflamed tissue can now be accomplished with the use of this analytic method. The results from this research indicate a baseline level of catecholamines in the uninflamed human dental pulp.

The objective of this in vitro study was to evaluate the efficacy of a variety of endodontic irrigating devices. This study utilized plastic blocks with artificial canals to simulate the clinical setting. The canals were instrumented, and red food dye was introduced into each canal. The blocks were placed in a jig to simulate maxillary and mandibular arch orientation. Irrigation was performed with: (a) B-D 22-gauge needle; (b) Monoject Endodontic Needle 23 and 27 gauge; (c) Max-i-Probe 25-, 28-, and 30-gauge probes; (d) Cavi-Endo ultrasonic handpiece; and (e) Micromega 1500 subsonic handpiece. A Sony Camcorder was used to record the effect of irrigation on the simulated canal contents. Tape review enabled the investigators to observe dye clearance effected by each modality. The Max-i-Probe probes were the most effective instrument used to clear dye from the simulated canals in both the mandibular and maxillary positions

The purpose of this in vitro study was to compare the apical seals achieved using retrograde amalgam fillings or the Nd:YAG laser. Freshly extracted teeth were randomly separated into groups that would have their apices treated either with a Nd:YAG laser or retrograde amalgam. After instrumentation and obturation, bacterial reservoirs were prepared in the coronal portion of canals. Teeth to receive retrofillings had their apices prepared and amalgams placed. Teeth to be lasered had no apical preparations. Teeth and culture media were then sterilized by irradiation. Streptococcus salivarius was deposited in the opened bacterial reservoirs. At intervals, culture media with an indicator in culture chambers was observed for color change. Specimens that demonstrated color change were cultured for S. salivarius. Under the conditions of this in vitro study, no statistically significant difference was found in bacterial leakage between the laser-treated group and the retrograde amalgam group

Pretreatment radiographs were taken using a paralleling device and measurement grid. The measurement controls obtained in that manner in 60 teeth were compared to measurements obtained from conventional radiographs taken during endodontic treatment. This study was undertaken to test the proposal that pretreatment radiographs taken with a paralleling device and measurement grid would make further radiographs for that purpose unnecessary, thus reducing patients' exposure to ionizing radiation.

Sixty recently extracted intact anterior teeth were filled with Cavit G or Cavit. They were examined for dye penetration at room temperature and subjected to temperature change. Under the test conditions Cavit G and Cavit were resistant to penetration by aqueous methylene blue dye.

Enamel acid-etching has become a widespread, popular clinical procedure in recent years. Numerous studies have investigated the nature of the acid-treated enamel. However, little or no information is presently available pertaining to the effects of acid treatment upon dental pulp tissue. A limited investigation was carried out on bilateral orthodontic extraction cases to determine the effects of enamel acid-etching upon healthy dental pulp. In each of five cases one premolar served as the experimental tooth, while the contralateral premolar served as the control. After a 24-hour postoperative interval there appeared to be no basic histologic difference between the experimental and control groups.

Previous investigators who attempted to identify mast cells in the dental pulp have used demineralizing or tooth-splitting procedures to obtain their tissue samples. However, Eda and Langeland15 found that the fluorescence of mast cells is destroyed by acid demineralizing agents. On the other hand, tooth splitting may damage the pulp by crushing it with forceps, or cutting and heating it with burs, stones, or discs. In the present study, we used the extirpated pulps from teeth in which endodontic access openings were made by means of high-speed rotary instruments with water spray. Metachromatic staining methods failed to demonstrate mast cells in any of the non-inflamed pulp specimens. Two of the inflamed pulp specimens revealed numerous mast cells which appeared intact and well preserved with no evidence of degranulation. As to the distribution of the mast cells, there was no correlation with the number and types of other inflammatory cells observed. Although several cells present in the specimens examined were suggestive of mast cells, only those cells that revealed definitive metachromasia were included in this study.