Local Anesthesia in Dentistry: Techniques and Drugs

The comparison between articaine and lidocaine as reference local anesthetics, the difference between infiltration, field block and nerve block, and the onset and duration times worth knowing.

Local anesthesia is the tool that has made modern dentistry essentially painless, and choosing the right drug and technique remains one of the most common clinical decisions in everyday practice. Lidocaine, available since 1948, was long considered the gold standard among amide-type local anesthetics, for its excellent balance of efficacy, low allergenicity and limited toxicity. Articaine, introduced later in dentistry (originally named carticaine in 1969, renamed articaine in 1984), has a distinctive chemical feature compared to other amide anesthetics: a thiophene ring giving it high lipid solubility, contributing to its clinical effectiveness.

Direct comparison between 4% articaine and 2% lidocaine, the subject of numerous systematic reviews and meta-analyses, generally indicates a higher likelihood of anesthetic success for articaine in several clinical subgroups, with effectiveness that according to some reviews is superior even in inferior alveolar nerve block in patients with irreversible pulpitis — one of the clinical situations where achieving deep, effective anesthesia is notoriously harder. Articaine's onset is typically 1.5-1.8 minutes at the maxillary level and 1.5-3.6 minutes for mandibular block, with pulpal anesthesia duration between 30 minutes and 2 hours.

In terms of technique, orofacial anesthesia is classified into three main categories. Local infiltration anesthetizes terminal nerve endings in the immediate vicinity of the injection site, and is the most common technique for treating a single tooth, especially at the maxillary level where cortical bone is more porous and allows good anesthetic diffusion. Field block anesthetizes terminal nerve branches over a wider area, allowing treatment of a segment slightly distal to the injection site. Nerve block, finally, anesthetizes the main branch of a specific nerve — the most common example being inferior alveolar nerve block — allowing treatment of the entire region innervated by that nerve trunk, typically necessary for the posterior mandible where denser cortical bone makes infiltration alone ineffective.

An often underestimated element concerns the concentration of epinephrine paired with the anesthetic as a vasoconstrictor: the standard 1:100,000 concentration offers the best trade-off between anesthetic duration and bleeding control in most healthy patients, while in patients with significant cardiovascular disease a more dilute concentration (1:200,000) may be preferable, which according to some studies produces less cardiovascular stimulation while still maintaining adequate anesthetic effectiveness for most procedures.

On Oralzon you'll find articaine- and lidocaine-based local anesthetics in various concentrations and formulations with epinephrine, along with all the instrumentation for infiltration, field block and nerve block techniques.