The purpose of this study is to determine whether OraVerse is safe and effective for the reversal of dental anesthesia in children 2 to 5 years of age weighing at least 10 kg.

This Phase 4 clinical study is designed as a multicenter, randomized, double-blinded, controlled study to evaluate the safety and efficacy of OraVerse in approximately 150 children 2 to 5 years of age. OraVerse or sham injection is administered at the completion of a dental procedure requiring local anesthesia with lidocaine 2% with 1:100,000 epinephrine. The dental procedure(s) comprising restoration/fillings shall be performed in a single quadrant of the mouth.

The primary endpoint is safety and tolerability of OraVerse as measured by adverse events, vital signs, oral cavity assessments, nerve injury, and analgesics for intraoral pain. Secondary objectives in subjects 4 and 5 years of age include the safety and tolerability of OraVerse as measured by pain assessments using W-B PRS and evaluation of efficacy assessed by a pediatric Functional Assessment Battery (pFAB) and standardized lip and tongue palpation procedure.

Inclusion Criteria:

• Male or female, 2 to 5 years of age

• Sufficiently healthy as determined by the Investigator to receive routine dental care

• Requires a restorative procedure (restoration/filling) in a single quadrant of the mouth

• Requires local anesthesia with lidocaine 2% with 1:100,000 epinephrine administered by submucosal injection

• For subjects undergoing mandibular procedures, require an inferior alveolar nerve block for the restorative procedure

• Dental procedure(s) completed within 60 minutes of injection of local anesthetic

• For subjects 4 and 5 years of age, can be trained in standardized lip/tongue palpation procedure and pFAB

• Subjects who are trainable in pFAB and standardized lip/tongue palpation procedure have either:

  • normal pFAB at baseline prior to administration of local anesthetic and
  • at least one abnormal function (smiling, speaking, drinking or drooling) at the completion of the dental procedure OR
  • normal lip sensation at baseline prior to administration of local anesthetic and
  • numbness of the relevant lip quadrant at completion of the dental procedure

• Subjects give written or verbal assent, as capable and appropriate, and parent(s) or legal guardian(s) give written informed consent

Exclusion Criteria:

• Weight less than 10 kg
• Weight less than 15 kg if 4 or 5 years of age
• History or presence of any condition that contraindicates routine dental care or use of local anesthetic
• Requires more than ¼ cartridge of local anesthetic if weight is ≥ 10 kg and < 15 kg, more than ½ cartridge of local anesthetic if weight is ≥ 15 kg and < 30 kg, and more than 1 cartridge of local anesthetic if weight is ≥ 30 kg, excluding supplemental injections
• Allergy or intolerance to lidocaine, epinephrine, sulfites, phentolamine, nitrous oxide or topical benzocaine
• Has used any investigational drug and/or participated in any clinical study within 30 days of study drug administration
• Has participated in this study or any previous study of phentolamine mesylate for reversal of local soft tissue anesthesia (STA)
• Any use of commercial OraVerse™ within 30 days of study drug administration
• Use of opioid or opioid-like analgesics within 24 hours prior to administration of local anesthetic
• Requires the use of local anesthetic other than lidocaine 2% with 1:100,000 epinephrine to perform the scheduled dental procedure
• Requires the use of general anesthesia or sedatives except for nitrous oxide to perform the scheduled dental procedure
• Any condition which in the opinion of the Investigator increases the risk to the subject of participating in this study or decreases the likelihood of compliance with the protocol