Comparative Study of the Anaesthetic Efficacy of 4% Articaine Versus 2% Mepivacaine in Mandibular Third Molar Germectomy Using Different Anaesthetic Techniques: a Split-mouth Clinical Trial

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.