The purpose of this study is to determine the effectiveness of buffered local anesthesia injections to numb the gums and teeth during dental treatment. Adjusting the pH of lidocaine with sodium bicarbonate may reduce the pain of injection for both adults and children. In this study, the investigators will compare two local anesthetic preparations, a buffered anesthetic and the conventionally available anesthetic, for pain upon injection.

Hypothesis: Anesthetic buffered to physiologic pH will result in a less painful injection compared to the acidic alternative used in most dental offices. This can be demonstrated by comparing two local anesthetic preparations, a buffered anesthetic and the conventionally available anesthetic, for pain upon injection.

Local anesthesia is an essential procedure in the comprehensive treatment of pediatric patients. In the treatment of subjects with dental disease and infection, local anesthesia is commonly required when performing operative procedures. The use of local anesthesia serves two main purposes: (i) enables the patient to remain free of discomfort during the sometimes painful procedure and (ii) permits the practitioner to complete the procedure without fear of hurting the patient which might otherwise impede the practitioner's ability to provide comprehensive care. However, patients are often fearful of local anesthesia because traditional preparations of local anesthesia are acidic and can be painful. Thus, an important advance in the areas of subject management and pain control during operative procedures would be a preparation of local anesthesia that significantly reduced the pain upon injection. A 2010 Cochrane Review found that adjusting the pH of lidocaine with sodium bicarbonate reduced the pain of injection for both adults and children. In this study, we will compare two local anesthetic preparations, a buffered anesthetic and the conventionally available anesthetic, for pain upon injection.

The study will test a local anesthetic buffering system, the Onset system, an FDA Class 1 compounding device manufactured by Onpharma Inc. It is a simple and portable local anesthesia buffering system that compounds anesthetic solution and 8.4% sodium bicarbonate neutralizing additive solution in a precise manner that brings the anesthetic solution up to human physiologic pH. Commercially available local anesthetics have a low pH to allow for prolonged shelf life, and to keep the anesthetic molecules in solution. The combination of a buffering sodium bicarbonate agent and local anesthetic has been reported to result in pain-free injections for both adults and children. The neutralizing additive solution is a sterile, nonpyrogenic, solution of sodium bicarbonate (NaHCO3) in water. pH is adjusted with carbon dioxide. Sodium Bicarbonate Inj., 8.4% USP Neutralizing Additive Solution (NDC Code 509-100-03) and Lidocaine w/ Epinephrine are compatible. Sodium bicarbonate is used in medicine and dentistry as regularly as saline, and pre-dates the FDA. It is commercially available and currently being used by health professionals in the U.S.A.

The local anesthetic used in the study will be 2% lidocaine with 1:100,000 ppm epinephrine, part of the amide family of local anesthetics. It has been widely used in dentistry and medicine and has long-standing proven records of safety.

Inclusion Criteria:

• Give written, informed consent (both the subject and the legal guardian)
• Be 9-12 years of age
• Be able to comprehend the visual analog scale (instructions given to ascertain this)
• Be able to comprehend the verbal rating scale (instructions given to ascertain this)
• In the opinion of the investigator, be a subject who can be expected to comply with the protocol
• Present moderate mandibular dental disease bilaterally
• Have 4 to 7 natural teeth (with at least one posterior tooth) present in each mandibular quadrant with moderate dental disease on at least one tooth
• Be willing to attend the clinic for 3 or more appointments

Exclusion Criteria:

• Antibiotic premedication requirement
• A history of allergy, sensitivity, or any other form of adverse reactions to local anesthetics of the amide type, or epinephrine
• A history of specific systemic illness that would preclude administration of a local anesthetic or vasoconstrictor (epinephrine) (e.g. liver , renal, cardiovascular diseases, blood dyscrasias, psychiatric disorders, etc.)
• A history of systemic illness that would interfere with healing response (e.g. liver disease, blood dyscrasias, uncontrolled diabetes, etc.)
• Current systemic medication that interferes with healing response
• Current systemic medication which contraindicates the use of local anesthetics or epinephrine
• Pregnant or lactating females (contradicts the use of local anesthetic in non-emergency type dental procedures)
• Current alcohol or drug abuse
• Received an anesthetic, analgesic or sedative within 24 hours prior to the therapy appointments
• Acute infections or conditions in the oral cavity requiring immediate treatment
• Participation in a clinical study of an investigational drug within the previous 4 weeks
• Previous enrollment in the present study

per protocol

up to 48 hours after treatment procedures

Participants were contacted by telephone within 48 hours and asked standardized follow-up questions to determine if there were any adverse reactions: 1. Have you had any health problems since you left the dental clinic?, 2. Have you had any soreness in your mouth since you left the dental clinic?, 2.a. If yes, is the soreness at the injection site?

The variation of VAS scores was found to be larger than that used in the sample size calculation; thus, the study was underpowered to reach statistical significance.