Clinical Outcomes Mandible: Buffered 1% vs. Non-Buffered 1% Lidocaine
Condition: Anesthesia, Local
Study type: Interventional
Phase: Phase 4

Summary: 
      Assess the clinical impact of Buffered 1% lidocaine with epinephrine as compared to the
      Non-buffered 1% lidocaine with epinephrine in dental and oral surgical procedures.
    

Detailed description: 
      Background:

      Based on the discovery of its topical and locally injected anesthetic effects at the end of
      the 19th century, cocaine was rapidly adopted as a means of blocking painful sensory impulses
      from the periphery during surgical procedures.(1) In the last decade local anesthetics have
      been administered more often, alone or in combination with IV or inhalation anesthetics for
      most surgical procedures. For clinical procedures in the head and neck the local anesthetic
      drugs have been combined with a vasoconstrictor, usually epinephrine, to prolong the
      anesthetic effect at the locally injected anatomic site. To achieve pulpal and periosteal
      anesthesia by nerve or field block for procedures in dentistry, lidocaine at a 2%
      concentration has been preferred by clinicians for its reliable outcomes. To prolong the
      shelf life of the vasopressor, the drug combination must be formulated with a low pH,
      approximately pH 3.5 for lidocaine with 1/100k epinephrine (Epi).

      With a better understanding of the pharmacology, new options for improving local anesthetic
      effectiveness including buffering the commercially supplied drugs to a neutral pH just prior
      to injection, continue to emerge.(2) When injected, the low pH causes the "sting" felt by
      patients on injection. Buffering to a neutral pH eliminates this discomfort and makes the
      maximum concentration of the non-ionized form of the anesthetic drug immediately available to
      the targeted nerve membrane.(3-7) Until recently, buffering local anesthetics containing Epi
      followed with bicarbonate just prior to injection was impractical for the quantities used in
      intraoral procedures. However, today we do have options to efficiently accomplish this
      buffering technique.(Anutra Medical, Research TrianglePark, NC).

      Buffering local anesthetics just prior to use produces positive outcomes including less
      "sting" on injection, faster onset of the drug, and possibly added drug potency, ie the same
      positive clinical effect at lower dosage. In pilot studies with healthy adults as their own
      controls investigators have shown that Buffered 1% lidocaine with 1/100k Epi was as effective
      as Non-buffered 2% lidocaine with 1/100k Epi for pulpal anesthesia on a 1st molar or canine
      after nerve block in the mandible or field block in the maxilla-Phase one of this study.(8,9)
      These outcomes could be beneficial for performing multiple procedures in children whose
      lidocaine dosage is limited by body weight or others with chronic liver disease.

      Rationale:

      The recently reported results from the two clinical studies involving buffered lidocaine with
      Epi have led to clinicians questioning whether the Buffered 1% lidocaine with Epi might be as
      effective for achieving pulpal and periosteal anesthesia for dental procedures as
      Non-Buffered 1% lidocaine with Epi-Phase two of this study, outcomes not usually considered
      by most clinicians. This protocol addresses that question.

      Specific Aims:

      Compare clinical depths of pulpal anesthesia for maxillary(Phase one) and mandibular(Phase
      two) molar and canine teeth at 30min intervals Post-injection of lidocaine Assess pain levels
      during injection Assess time after injection to lower lip numb

      Hypotheses:

      No differences exist in anesthetic depth for pulpal anesthesia after intraoral injection
      mandibular nerve block between Buffered 1% lidocaine with 1/100k epinephrine as compared to
      Non-buffered 1% lidocaine with 1/100k epinephrine.

      Subjects will serve as their own controls in a cross-over AB/BA study design which is uniform
      within sequences, uniform within periods, and balanced
    

Intervention name(s): Lidocaine
Intervention type(s): Drug
Intervention description(s): Efficacy for mandibular molar and canine anesthesia
Other intervention name(s): xylocaine
Intervention MeSH terms: Lidocaine
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Double (Participant, Care Provider)
Primary purpose: Treatment
Keywords: lidocaine, mandible