Efficacy of Differents Anaesthetics in Mandibular Third Molar Germectomy
Condition: Local Anesthetic Efficacy
Study type: Interventional

Summary: 
      Aim: To compare the clinical efficacy of local anaesthetics with articaine 4% or mepivacaine
      2% (both with epinephrine 1:100.000) using different anaesthetic techniques to perform
      germectomy of lower third molars and to assess patients' feelings and pain during surgery.

      Methods: 50 patients (ranged 11-16 years) who required germectomy of mandibular third molars
      were recruited. Each patient received local anaesthesia on one side with articaine inoculated
      with plexus technique while on the other side with mepivacaine using inferior alveolar nerve
      block technique. The patients' evaluation was performed on pre and intraoperative
      tactile-pressure feelings and intraoperative pain with four levels on the analogic visual
      scale (VAS).
    

Detailed description: 
      The surgical extraction of a tooth that exhibits at least a third of its root in formation,
      with a periodontal ligament discernible on panoramic x-ray, is defined as germectomy. Early
      germectomy is a usefull intervention to avoid problems caused by lower third molar retention
      and impaction, and it is often required before or after orthodontic treatment. This surgical
      technique would also allow to avoid complications, such as inferior alveolar and lingual
      nerve damage.

      The control of the patient's pain and anxiety by using local anaesthesia is essential in oral
      surgery: these aspects become more important in adolescents, above all in the case of third
      molar germectomy. Local anaesthetic (LA) injection is often the only painfull part of the
      dental procedure, and the fear associated with this technique is the main reason that leads
      patients to avoid dental treatment.

      During the execution of dental surgical procedures, anaesthesia of the structures innervated
      by the mandibular nerve is necessary, and many local anaesthetic techniques are described in
      the literature. Generally, infiltration plexus technique is usually performed for maxillary
      procedures while IANB is used for molar mandibular sites with 2% local anaesthetics. Failure
      rates for IANB are high, sometimes reaching 80% for the lower incisors with this technique,
      and numerous approaches for the implementation of a new technique of IANB have been
      described. Among them, the articaine 4% already has been successfully used to achieve local
      anesthesia and facial infiltration anaesthetic technique in the mandible showed efficacy with
      encouraging result that can be overlapped to the IANB technique. Articaine
      (4-methyl-3-[2-(propylamino)-propionamido]-2-thiophene-carboxylic acid, methyl ester
      hydrochloride) contains a thiophene ring instead of benzene and an ester group. The thiophene
      ring allows for higher lipid solubility so a greater portion of an administered dose can
      enter in neurons. Gazal found that a combination of nerve block anaesthesia, buccal
      infiltration and intra-ligamentary injection resulted in more profound anaesthesia (P =0.003)
      and higher success rates compared to IANB alone in mandibular first molar pulp anaesthesia.
      Other studies reported the use of articaine in implantology interventions in which it was
      used with subperiosteal technique on the buccal and vestibular sides.

      Thus, the literature showed several conflicting results on the mandibular facial plexus
      infiltration technique used with different anesthetics.

      Recent studies of this anaesthetic technique found that 1.8 cc of 4% articaine facial
      infiltration in the mandible can be effective when the thickness of mandibular facial cortex
      is < 2.0-3.0 mm, with 5-10 minutes needed for the adequate anaesthesia.

      It was reported that many dental procedures on deciduous molars could be accomplished with
      infiltration of articaine alone in the pediatric population.

      As above mentioned, the difficulty in achieving reliable anaesthesia in the third mandibular
      molars in adults with facial infiltration of local anaesthetic is related to the thickness of
      the cortical bone and inability to achieve consistently inferior alveolar nerve.

      An ideal local anaesthetic should have the following characteristics:

        1. short latency time;

        2. strength of the intense effect;

        3. duration of prolonged action;

        4. lack of harmful local and systemic effects. Currently, mepivacaine is among the most
           used and studied anaesthetics in dentistry; however, articaine is nowadays increasingly
           used for its manageability, lack of side effects and high anaesthetic potency.
           Mepivacaine is an amide-type anaesthetic with fast action from the beginning and 30-120
           minutes duration. Its maximum allowed dose is 300 mg with epinephrine or 500 mg alone.
           The dose for children is 4-6 mg/kg/dose (maximum: 270 mg) without epinephrine.

      Articaine, due to its chemical characteristics, is quickly soluble and rapidly released from
      adipose/lipid tissue. The ester side chain of articaine is hydrolyzed by plasmaesterases
      rendering the molecule inactive. Evidence suggests that it is the local anaesthetic that best
      spreads within soft and hard tissues. Then, it has a non-conducive effect on extended
      operations having a shorter half-life of 25 minutes compared to approximately 90 minutes of
      other amides (115 minutes for mepivacaine) that require hepatic clearance. Accordingly, it
      was suggested that articaine does not own any relevant side effects or systemic toxicities.

      For this reason, articaine has been used at higher concentrations (4%), associated with
      epinephrine, compared to other local dental anesthetics. This higher concentration ensures an
      excellent spread both in hard and soft tissues, also promoted by a pKa very similar to the
      physiological pH of tissues. Its great liposolubility allows a rapid diffusion in adipose
      tissue (spread coefficient = 17,0) and involves a lower adherence to the nerve membranes and,
      above all, lower toxicity for the tissues. Moreover, articaine has a high protein-based bond
      (94%) which allows a better affinity for the protein-based membrane receptors, and it is a
      direct sign of its increased anaesthetic potency.

      Dental local anaesthetics are often combined with vasoconstrictors, such as epinephrine, to
      increase the depth and duration of analgesia. Clinical experiments, in which articaine
      without vasoconstrictor was used, did not show any satisfying results, whereas the use of
      articaine combined with low concentrations of vasoconstrictors produced better anaesthetic
      effects than other common local anaesthetics such as bupivacaine and mepivacaine. It is well
      documented that vasoconstrictors have a safety range if used at low doses, and not directly
      injected in the blood vessels, even in particular care patients.

      The present study aimed to compare the clinical efficacy of articaine 4% (epinephrine
      1:100.000) versus mepivacaine 2% (epinephrine 1:100.000) for the surgical germectomy of
      mandibular third molars with two different conventional anaesthetic techniques in young
      patients whom jawbone is not completely mineralized yet and more penetrable by the articaine
      molecule.
    

Intervention name(s): Third Molar Germectomy
Intervention type(s): Procedure
Intervention description(s): Surgical extraction of Third Molars that exhibits at least a third of its root in formation, with a periodontal ligament discernible on panoramic x-ray (defined as germectomy).
Intervention model: Single Group Assignment
Intervention model description: The subjects were children undergoing orthodontic treatment in whom early extraction was indicated to facilitate their treatment in some specific conditions (i.e. posterior crowding, altered second molar eruption, non-extraction approach). For each subject, the first germectomy was scheduled 15 days apart. The same senior operator, assisted by the same practitioner, completed all the surgical procedures. All interventions made with mepivacaine were performed with the same anaesthetic technique routinely used in Oral surgery (IANB). The technique was complemented with anaesthesia of the buccal nerve, as routine for this technique, administering another 1.8 ml of the same anaesthetic used in each intervention. On the other hand, the surgical procedures in articaine cases were made practising a plexus technique, performing a deep buccal injection distally to the second mandibular molar.
Masking: None (Open Label)
Primary purpose: Supportive Care