An ex vivo comparison of pressures within dental pulp space using conventional anesthetic technique versus needle-mounted obturator.

INTRODUCTION: The intrapulpal (IP) injection technique is 1 of several ways of obtaining profound anesthesia. There is evidence to suggest that pressure is the primary factor in obtaining anesthesia using IP injection. This is an ex vivo comparison of pressures within dental pulp space using the conventional anesthetic technique versus a needle-mounted obturator technique. METHODS: Twenty extracted anterior and premolar teeth were accessed with a high-speed 169L bur. A saline-filled tube connected to a digital pressure gauge was attached to the apical 10 mm of each tooth in a fixed mount. One operator performed all the injections under moderate pressure. Each tooth was injected twice; first, the tooth was given an IP injection with a normal setup, and then the same tooth was given an IP injection with the modified obturator syringe. The pressure at the apex was recorded for each tooth. A paired sample t test was completed to determine statistical significance. RESULTS: The pressure generated was considerably higher for the obturator group in every tooth when compared with the normal group (P < .001). CONCLUSIONS: IP injection with the obturator resulted in increased pressure at the apex of each tooth. This pressure increase may allow for increased anesthesia when IP injections are indicated.

Use of saliva for assessment of stress and its effect on the immune system prior to gross anatomy practical examinations.

The objective of this study was to determine the longitudinal effects of a series of stressful gross anatomy tests on the immune system. Thirty-six freshman occupational therapy students completed a written stress evaluation survey, and saliva samples were obtained at baseline and prior to each of three timed-practical gross anatomy tests. Cortisol, secretory IgA (sIgA), and IL-12 concentrations were measured within the salivary samples by enzyme-linked immunosorbent assay. The total scores from the stress surveys were used as markers for environmental stress. Data were compiled for each student at baseline and prior to each examination and were compared by repeated-measures MANOVA and Pearson's correlation test. Following normalization for protein concentration and flow rate, the concentrations of IL-2, IL-6, IL-12, and sIgA progressively increased from baseline to the third test. Cortisol concentrations, following normalization for flow rate, were highest prior to the first test and became significantly reduced prior to second and third test. Prior to second and third test, salivary concentrations of IL-6, IL-2, IL-12, and sIgA were significantly correlated (P < 0.05). In contrast, prior to third test, there was a negative correlation between salivary concentrations of cortisol and IL-12 (P < 0.05). Progressive increases in salivary sIgA, IL-6, IL-2, and IL-12 concentrations from the first to the third test coincident to decreased salivary cortisol suggest that the initial examination stressors precede significant effects on the immune system. These data suggest that there may be latent effects of examination stress on the immune system and that saliva can be used to predict these effects.