Comparison of Anesthetic Efficacy of Bilateral and Unillateral Application of Kovacaine Mist in Healthy Volunteers

To compare the efficacy of Kovacaine Mist administered bilaterally to that of Kovacaine Mist administered unilaterally with respect to global profound pulpal anesthesia in target teeth numbers 4-13.

Qualified and consenting healthy subjects will be randomly assigned in a double-blind manner to sequences of four randomly ordered study periods with inter-treatment "washout" periods of 3 to 14 days. The four study regimens, which will be applied in random order will be:

* Regimen1. Three sprays of Kovacaine Mist in each nostril (bilateral dosing);
* Regimen 2. Three sprays of Kovacaine Mist in the right nostril and three sprays of placebo in the left nostril (right-sided unilateral dosing);
* Regimen 3. Three sprays of Kovacaine Mist in the left nostril and three sprays of placebo in the right nostril (left-sided unilateral dosing);
* Regimen 4. Three sprays of placebo in each nostril (placebo dosing).

During each testing period, eight representative maxillary teeth (#s 3, 4, 6, 8, 9, 11, 13 and 14) will be assessed for anesthesia using standard EPT testing. EPT testing will be conducted on the eight representative teeth at the following time points (minutes relative to the first spray of study drug): T-5, T3, T7, T11, T16, T21, T26T31, T41, T51, T61, T76, T91, T121, T151, and T181. If EPT testing of a target tooth is not possible (e.g., missing or does not meet inclusion criterion #2) tooth substitution is permissible. For molar teeth, #2 may replace #3 and #15 may replace #14. For premolar teeth, #5 may replace #4 and #12 may replace #13. The same replacements will be made for all testing sessions, and the actual teeth tested will be documented in the CRF.

Eligibility Criteria:
Inclusion Criteria:

* Male or female 18 years of age or older.
* Eight representative maxillary teeth \[(3 (or 2), 4 (or 5), 6, 8, 9, 11, 13 (or 12), and 14 (or15)\] free of observable decay (or other pathology), crowns or veneers, all of which have EPT values of 10-50 at screening.
* Normal lip, nose, eyelid, palate, and cheek sensation.
* Patency of both left and right nasal airways.
* Ability to understand and willingness to sign the study informed consent form, communicate with study investigators, and understand and comply with the requirements of the study protocol.

Exclusion Criteria:

* Poorly controlled hypertension (blood pressure greater than 150/90 mmHg) or history of coronary heart disease.
* Diabetes mellitus.
* Any active thyroid disease other than S/P thyroidectomy on thyroid hormone replacement with TSH values in the normal range.
* History or presence of narrow-angle glaucoma.
* Prostatic enlargement.
* History of sinus/nasal surgery that, in the opinion of the investigator, could confound study results.
* History of frequent nose bleeds.
* Receipt of dental care requiring a local anesthetic within the last 24 hours.
* History of allergy to or intolerance of tetracaine, benzyl alcohol, benzocaine, other ester local anesthetics, succinylcholine, or para-aminobenzoic acid (as found in PABA-containing sunscreens).
* History of allergy or hypersensitivity to articaine, oxymetazoline, epinephrine, or sulfite antioxidants.
* History of drug abuse.
* Use of a monoamine oxidase inhibitor within the 3 weeks immediately prior to anticipated study participation.
* Nursing, pregnant, suspected of being pregnant, or trying to become pregnant. (Females will be required to undergo pregnancy testing to rule out pregnancy)
* Use of any investigational drug and/or participation in a clinical research trial within 30 days of the first study dosing day.
* Requirement for uninterrupted use of any medication with actions that might, in the opinion of the involved investigator, confound interpretation of study results.