or altered sensation affecting a nerve, is a well-known complication of injectable local anesthetics and has been present even before articaine was available. An article by Haas and Lennon published in 1993 seems to be the original source for the controversy surrounding articaine. This paper analyzed 143 cases reported in to the Royal College of Dental Surgeons of Ontario (RCDSO) over a 21-year period. The results from their analysis seemed to indicate that 4% local anesthetics had a higher incidence of causing paresthesia, an undesirable temporary or permanent complication, after the injection. The authors concluded that “...the overall incidence of paresthesia following local anesthetic administration for non-surgical procedures in dentistry in Ontario is very low, with only 14 cases being reported out of an estimated 11,000,000 injections in 1993. However if paresthesia does occur, the results of this study are consistent with the suggestion that it is significantly more likely to do so if either articaine or prilocaine is used.” In another paper by the same authors, 19 reported paresthesia cases in Ontario for 1994 were reviewed, concluding that the incidence of paresthesia was 2.05 per million injections of 4% anesthetic drugs. Another follow up study by Miller and Haas published in 2000, concluded that the incidence of paresthesia from either prilocaine or articaine (the only two 4% drugs in the dental market) was close to 1:500,000 injections. (An average dentist gives around 1,800 injections in a year.) Almost all recorded cases of long-term numbness or altered sensation (paresthesia) seem only to be present when this anesthetic is used for dental use (no PubMed references for paresthesia with articaine for other medical specialties). Also, in the vast majority of the reports, only the lingual nerve was affected. Nonetheless, direct damage to the nerve caused by 4% drugs has never been scientifically proven. Some research points to needle trauma as the cause of the paresthesia events. References External links Carticaine(articaine) PubChem page Orabloc Septodont Structure Permanent Nerve Damage from Inferior Alveolar Nerve Blocks: An update to include articaine. Permanent nerve involvement resulting from inferior alveolar nerve blocks. Nerve damage associated with inferior alveolar nerve blocks. Local anesthetics Dental equipment Thiophenes AstraZeneca brands Carboxylate esters Propionamides Methyl esters