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Biomedical subjects

T C Dumsha

Publications and source records attributed to T C Dumsha.

18 recordsLinked to original sources
PubMed1998

Effect of soaking in Hank's balanced salt solution or milk on PDL cell viability of dry stored human teeth.

This study was designed to evaluate the effect of soaking in either Hank's balanced salt solution (HBSS) or milk on periodontal ligament (PDL) cell viability in avulsed teeth. Dry storage times of 30, 60, and 90 min were evaluated. PDL cell viability was determined after removal of the cells from the root surfaces of extracted teeth using a modification of the procedure described by Nakashima (Arch Oral Biol 1991;36:655-63). After trypsinization and subsequent treatment in collagenase, the cells were stained with trypan blue, and viable and non-viable cells were counted using a hemocytometer and converted to percentages for statistical comparison. The results of this study demonstrated no significant difference in the number of viable cells with or without soaking in HBSS or milk at any of the dry storage times. In addition, there was no significant difference in PDL cell viability between the 30-and the 60-min dry periods. Although the soaking procedure had no obvious negative consequence, no significant improvement in PDL cell viability by the addition of this step was demonstrated under the conditions of this study.

Adolescent↗
PubMed1996

The reliability of electric pulp test after concussion injury.

Traumatic injuries to teeth present a difficult diagnostic problem with respect to determining the vitality of the affected teeth. Conventionally, a latency period of 4 to 6 weeks is proposed as the amount of time required for the return of a positive electric pulp test (EPT) response; however, this has been based on empirical data. The purpose of this study was to 1) determine a time frame during which a return of a reliable response to EPT may be measured, and 2) correlate this time frame with pulpal vascular changes that occur after traumatic injuries. Four canines from each of nine ferrets were used for this experiment (18 traumatized and 18 control teeth). A reproducible concussion injury was devised by releasing a known weight at a constant height above the facial surface of the experimental teeth. The EPT response was confirmed by the use of an EMG muscle recorder. Animals were killed at 24, 48 and 72 h and 6, 12 and 28 days after the injury and the teeth analyzed histologically. The histological sections showed an absence of inflammatory cells in both groups; however, according to the NIH image system, an increase in the number of vessels was detected in the experimental group when compared to the controls. In a majority of the cases, a positive response to the EPT returned within 12 days post concussion injury and as early as 10 days. In addition, a significant vascular change was accompanied with the loss of the EPT response. This study provided a reliable method by which concussion injuries may be studied using an animal model.

Analysis of Variance↗
PubMed1995

Luxation injuries.

Luxation injuries range in severity from a mild blow to a more severe form, which can cause pulpal necrosis and additional sequelae. This article reviews the epidemiology and describes the various classifications, the appropriate treatment, and the various sequelae of luxation injuries.

Dental Pulp Calcification↗
PubMed1994

Determining periodontal ligament (PDL) cell vitality from exarticulated teeth stored in saline or milk using fluorescein diacetate.

One of the key factors for obtaining a favourable long-term prognosis in avulsed teeth is maintenance of the vitality of the periodontal ligament (PDL) cells. Most studies which have examined PDL cell vitality have used neutral red or trypan blue as stains. However, these stains have certain inherent disadvantages. The purpose of this paper was to (i) evaluate the use of saline and milk as storage media for PDL cells and (ii) determine the value of using fluorescein diacetate (FDA) as a staining medium for vital PDL cells on the root surface of avulsed teeth. Thirty-two single-rooted premolars were utilized from patients aged 13 to 28 years. Following atraumatic extraction, the teeth in the experimental groups were air dried for 10 min and then placed in either milk or saline for 120 min. Both control and experimental teeth were subjected to trypsinization procedures, staining with FDA, and haemocytometer readings to determine the number of vital cells. There was no statistically significant difference in the number of viable cells on the root surfaces of teeth after 2 h of storage in either milk or in saline. Furthermore, staining with FDA provided an excellent method by which to determine PDL cell vitality.

Adolescent↗
PubMed1992

Management of avulsions.

The treatment of the avulsed tooth provides a significant challenge to the dental practitioner. It is obvious that this particular dental injury poses a significant number of questions for both the researcher and the clinician. There will be most likely a continued interest to find the ideal treatment for this injury. As much as the dental literature has provided an improvement to the treatment of patients with avulsed teeth, however, there remains a significant number of clinically relevant questions that must be addressed before patients who sustain avulsion injuries can receive an acceptable long-term prognosis.

Humans↗
PubMed1990

Anatomical study of the position of the mesial roots of mandibular molars.

In order to determine the position of the anatomical apex of the mesial roots of the first and second molars, the horizontal distance from the outer surface of the buccal cortical plate to the apex and the vertical distance from the superior border of the neurovascular bundle to the apex were examined in 33 human cadaver mandible halves. The vertical distances were compared with measurements taken from periapical radiographs between the apex of each mesial root and the superior border of the mandibular canal prior to sectioning. The means of the horizontal buccal distances of the second molar were found to be significantly greater than those of the first molar. The means of the vertical distances of the second molar were found to be significantly less than those of the first molar. A high correlation was found between the vertical anatomic and radiographic measurements. In the majority of the sections, the neurovascular bundle was found in the lingual half of the mandible.

Adult↗
PubMed1985

Cytotoxicity testing of a dentin bonding system.

The cytotoxicity of a newly developed dentin bonding system was examined in African green monkey kidney cells and human embryonic lung cells. A tissue culture agar overlay procedure, a longitudinal study, and a cell replication assay were employed to evaluate cytotoxicity. Several of the components were discovered to be cytotoxic when tested individually in vitro. However, when used in the prescribed manner, little or no cytotoxic effect was elicited. The results of this study support further testing of these materials in vivo.

Animals↗
PubMed1984

Marginal leakage of class V cavity preparations.

Dentin-bonding materials, ferric oxylate (FO), addition reaction between N-phenylglycine and glycidyl methacrylate (NPG-GMA), and addition reaction product of pyromellitic acid dianhydride and 2-hydroxyethyl methacrylate (PMDM), were tested together for their ability to inhibit marginal leakage in Class V composite restorations in vitro. Sixteen experimental teeth were pretreated with FO, NPG-GMA, PMDM, and restored with composite. Sixteen control teeth were treated conventionally with composite. The teeth were then thermally cycled (5 and 55 degrees C) for 7 days, silver stained, and evaluated blindly for degree of marginal leakage on a scale of 0 (no leakage) to 7 (leakage into the pulp). The experimental group displayed significantly greater leakage values (p less than 0.01) than controls. The results of this study support the hypothesis that FO, NPG-GMA, and PMDM, together with composite inhibit marginal leakage.

Composite Resins↗