This Phase 2 clinical study is designed as a multicenter, randomized, blinded, controlled study to evaluate the safety and efficacy of NV-101 in approximately 150 children 4 to 11 years of age. NV-101 or sham injection is administered at the completion of a dental procedure requiring local anesthesia with 2% lidocaine with 1:100,000 epinephrine. The dental procedure(s) shall be performed in a single quadrant of the mouth and include cavity preparation, restoration/filling, teeth cleaning (non-surgical scaling and/or root planing), or crowns.

Inclusion Criteria:

• Male or female, 4 to 11 years of age

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

• Requires a restorative procedure such as cavity preparation, or such as teeth cleaning (non-surgical scaling and/or root planing) in a single quadrant of the mouth

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

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

• Can be trained to complete the Wong Baker Pain Rating Scale

• For subjects 6 to 11 years of age who are trainable in standardized palpation procedure:

  • have normal lip sensation at baseline prior to administration of local anesthetic
  • have numbness of the relevant lip quadrant at completion of the dental procedure

• Negative urine pregnancy test at screening in female subjects who are past menarche

• Subjects give written or verbal assent, as applicable, and parents(s) or legal guardian(s) give written informed consent

Exclusion Criteria:

• Weight less than 15 kg
• History or presence of any condition that contraindicates routine dental care or use of local anesthetic
• Requires more than half cartridge of local anesthetic if weight is greater than or equal to 15 kg and less than 30 kg and more than one cartridge of local anesthetic if weight is greater than or equal to 30 kg, excluding supplemental injections
• Allergy or intolerance to lidocaine, epinephrine, sulfites, phentolamine, 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)
• Use of opioid-like analgesics within 24 hours prior to administration of local anesthetic
• Requires the use of local anesthetic other than lidocaine/epinephrine to perform the scheduled dental procedure
• Requires the use of nitrous oxide or sedatives to perform the scheduled dental procedure
• Any condition which, in the opinion of the Investigator, increases the risk to the subject of participating in the study or decreases the likelihood of compliance with the protocol