The effects of periodontal therapy on the mast cell population in gingival tissues.

The histologic condition of the gingival tissues was determined prior to and 4 weeks after scaling and curettage, then 4 months after periodontal osseous surgery in a group of eight patients with chronic periodontitis. The histopathologic changes were correlated with variations in mast cell population following the different modes of periodontal therapy.

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.

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 (PMN's) 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.

Comparison of human polymorphonuclear neutrophil elastase, polymorphonuclear neutrophil cathepsin-G, and alpha 2-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).

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.

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.

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.