Edward J. Kaminski

Risk assessment of the toxicity of solvents of gutta-percha used in endodontic retreatment

Three randomly assigned groups of single-canaled extracted teeth obturated with gutta-percha were retreated using controlled application of one of three organic solvents: chloroform, xylene, or halothane. Two additional groups of teeth served as positive and negative controls. Residual volume of solvent expressed through the apical foramen during retreatment was determined by the difference of pretreatment and posttreatment weights of hermetically sealed receptacles attached to the root surface of the teeth. Results indicate that the amount of solvent that has been determined to have leached out through the apical foramen is several orders of magnitude below the permissible toxic dose. Thus, it is proposed that the use of any of the aforementioned solvents used in the retreatment of root canals would pose negligible risk to the patient.

A method for producing experimental simple vertical root fractures in dog teeth

Vertical root fractures present difficult diagnostic problems and have poor prognoses. Treatment of root fractures consists of osseous recontouring, hemisection, and root amputation or sealing medicaments into the root canal in an effort to promote defect calcification. Dogs are often used as models for root fracture studies; however, production of simple vertical fractures has been inconsistent with high rates (18 to 65%) of undesired fragmented fractures. A technique to reproducibly create simple vertical fractures with minimal trauma and low fragmentation is described. Selected posterior dog teeth were endodontically instrumented. A 60-degree beveled tip conical wedge was controllable driven apically to cause fracture. The teeth were then medicated with experimental compounds and sealed with glass ionomer cement. After 8 wk, the animals were killed and the mandibles and maxillae dissected free and serially sectioned. Light microscopic examination revealed that most of the teeth fractured (93%) were the simple vertical type.

Biological and physical properties of an experimentalroot canal sealer without eugenol

Abstract The working time, setting time, set hardness, setting pH, sealing potential, and biocompatibility of an experimental root canal sealer without eugenol were compared with those of two other root canal sealers that contain eugenol. The working and setting times for the sealer without eugenol were longer than those for the sealers with eugenol at 25 C. The setting times for all sealers were similar at approximately 37 C. Set hardness, pH, and sealing ability were similar for all the sealers tested. At less than 96 hours, the sealer without eugenol was more tissue-compatible than the sealers containing eugenol. After six months, the biocompatibility of all the sealers tested was similar.

A comparative study of the wound healing of three types of flap design used in periapical surgery

The clinical and histological features of wound healing of three common types of surgical flap designs used in periapical surgery were evaluated. A semilunar incision of alveolar mucosa, a submarginal incision of attached gingiva, and an intrasulcular incision of the attachment apparatus and papillae of the teeth were performed on beagles and observed at intervals of up to 60 days. Inflammatory changes persisted longer in the semilunar and intrasulcular incisions and retarded healing of the wound. Loss of alveolar bone occurred with the intrasulcular incision. Visible scarring occurred in the submarginal and semilunar incisions.

A comparative study of tooth apexification in the dog

Calcium hydroxide, collagen-calcium phosphate gel, and blood clot were compared as inducers of periapical calcification in the immature nonvital teeth of dogs. This investigation showed that calcium hydroxide accelerated hard tissue bridging of the open apex irrespective of complete resolution of initially induced inflammatory state. Collagen-calcium phosphate gel inhibited the reparative process of the initial inflammatory lesion leading to extensive destruction of the periapical tissues with no evidence of apexification. Locally induced blood clot maintained the initial inflammatory state and did not result in hard tissue bridging of the open apex. The investigation confrmed the use of the dog as an effective animal model for meeting the criteria of the experimental design.

Comparison of human polymorphonuclear neutrophil elastase, polymorphonuclear neutrophil cathepsin-G, and α2-macroglobulin levels in healthy and inflamed dental pulps

Polymorphonuclear neutrophils (PMNs) are found in dental pulp secondary to carious exposures, periodontal disease, or trauma. Lysosomal degranulation of these cells liberates cellular proteases, including elastase (PMN-E) and cathepsin-G (PMN-CG), which produce connective tissue degradation. However, nonspecific pulpal tissue destruction can be modified by a naturally occurring serum protease inhibitor alpha 2-macroglobulin (A2-M). This study relates the concentrations of human PMN-E, PMN-CG, and A2-M in healthy and inflamed pulpal samples. Evaluation of 21 specimens yielded statistically significant differences between healthy and moderate to severely inflamed pulps for all groups (p < 0.05). No significant correlation was detected among human PMN-E, PMN-CG, and A2-M in the healthy tissues (P > 0.05). However, in the moderate to severely inflamed pulps, there was a significant correlation between PMN-CG and A2-M (p < 0.05).

Human Polymorphonuclear Granule Components: Relative Levels Detected by a Modified Enzyme- linked Immunosorbent Assay in Normal and Inflamed Dental Pulps

Lysosomal granules of polymorphonuclear leukocytes (PMNs) contain proteolytic enzymes and other components important in the regulation of inflammation and the elimination of bacteria or debris associated with pulp disease. However, PMN lysosomal degranulation is nonspecific and can result in destruction of healthy connective tissue adjacent to the areas of damaged or infected tissue. For this study a modified enzyme-linked immunosorbent assay was used to detect the human PMN lysosomal granule products: elastase, cathepsin G, and lactoferrin. Evaluation of 55 pulp samples yielded a statistically significant difference (p less than 0.05) among the levels of elastase and lactoferrin in normal and moderate to severely inflamed pulps. Although cathepsin G levels were increased, there was no statistical significance (p greater than 0.05) among groups. The results indicate that a modified enzyme-linked immunosorbent assay technique can be used to measure PMN lysosomal granule components in dental pulp tissues. Additionally, elastase and lactoferrin levels appear to be valid diagnostic markers of advanced dental pulp disease.

Immunosuppression in adult female B6C3F1 mice by chronic exposure to ethanol in a liquid diet.

The overall objective of these studies was to characterize the effects of ethanol on the immunocompetence of adult female B6C3F1 mice. To obtain a significant suppression in the antibody response to SRBC, splenocytes from untreated mice had to be directly exposed to concentrations of ethanol from 0.3% to 3.0%, or to acetaldehyde at concentrations greater than 0.03%. We do not believe that these results are consistent with a role by a direct effect by either ethanol or its primary metabolite because these concentrations are higher than what could be obtained as reasonable blood levels. For in vivo exposure, we employed a pair-feeding regimen which was based on a liquid diet containing 5% ethanol (v/v) that provided 36% of the caloric intake as ethanol. Our results indicated that there was a definite temporal relationship to the consequent suppression of the antibody response to SRBC in that no effect was observed after 14 days exposure, and that the magnitude of the suppression increased from 18% after 21 days to 70% after 42 days. We also monitored the liver for histopathology and observed that the ethanol-induced liver damage was restricted to steatosis (fatty liver), which was also manifested with time and which was most pronounced after 42 days exposure. In contrast to our results with the in vivo antibody response, we saw no effect on mitogen-induced proliferation by splenocytes from ethanol-treated mice. These results prompted us to measure in vitro antibody responses by splenocytes from ethanol-treated mice. We saw no suppression of the in vitro antibody responses to SRBC, DNP-Ficoll or LPS after any length of exposure to ethanol, and speculated that the basis for the suppression of the in vivo antibody response was an indirect consequence of exposure. We subsequently determined that when normal splenocytes were cultured in 5% serum from ethanol-exposed mice (42-day group), there was a > 80% suppression relative to the serum from the pair-fed controls. As important controls for these studies, we have demonstrated that there was no difference between the responses of normal lymphocytes cultured in 5% normal mouse serum and in 5% serum taken from the pair-fed restricted controls. A determination of the ethanol content in the serum from ethanol-exposed mice (42-day group) indicated that the amount of ethanol present in these cultures was < 0.003%.(ABSTRACT TRUNCATED AT 400 WORDS)

Natural modifiers of the inflammatory process in the human dental pulp

Concentrations of the protease inhibitors alpha 1-antitrypsin and alpha 2-macroglobulin were determined in normal and inflamed human dental pulps. Carious pulpal exposure which is associated with polymorphonuclear leukocyte infiltration and release of lysosomal enzymes was chosen as the point of verifiable inflammatory activity in the pulp. Normal samples were collected from nondiseased third molar teeth treatment planned for extraction and inflamed human pulps were collected from teeth with deep carious lesions. One half of each sample was assayed for concentration of protease inhibitors by enzyme-linked immunosorbent assay and the remaining half was examined histologically to verify the clinical diagnosis and categorize the extent of the inflammatory process. alpha 1-Antitrypsin and alpha 2-macroglobulin were detected in normal and inflamed human dental pulps in the nanogram per milliliter range. Statistically significant differences were found in the concentrations of alpha 2-macroglobulin (p less than 0.01) in moderate to severe inflammation versus normal pulp categories and between mildly inflamed pulps and moderate to severely inflamed pulps (p less than 0.05). Although differences in concentrations of alpha 1-antitrypsin were seen between inflamed and normal pulps, the differences were not statistically significant. The presence of these two protease inhibitors in the human dental pulp tissue and the increase in their concentration in acute inflammation indicates that these proteins play a role in the pathogenesis of pulpal inflammatory disease.

Determination and Relationship of C-Reactive Protein in Human Dental Pulps and in Serum

C-reactive protein (CRP), an acute phase protein synthesized by the liver, increases in serum as much as 3000 times above its normal level in response to acute inflammation. The purpose of this study was to determine whether CRP levels in dental pulps could be correlated with the histological disease status of the pulp and with systemic blood levels of CRP. Inflamed and necrotic pulps were extirpated during routine endodontic therapy. Normal pulps were removed from extracted, intact third molars. One half of each pulp specimen was placed in formalin for histological study; the other half was frozen for immunological study. A serum sample was obtained from each patient at the end of the dental visit. CRP levels were determined by the enzyme-linked immunosorbent assay. Pulps were categorized histologically as normal, inflamed, inflamed/necrotic, or necrotic. The correlation between CRP levels of pulp and serum was not significant. CRP levels of normal pulps differed significantly only from inflamed pulps (p less than 0.05, Dunnett). This increase in CRP appears to be a local phenomenon resulting from the interaction of CRP with various inflammatory mediators in the pulp.