RESUMEN
BACKGROUND: To compare acceptance and preference of topical lidocaine gel anesthesia with articaine injection anesthesia in patients with moderate periodontitis undergoing scaling and root debridement. METHODS: Ninety-one patients completed this randomized multicenter split-mouth controlled study and underwent two separate periodontal treatment sessions on different days, one with a topical intrapocket lidocaine gel application and the other with an articaine injection anesthesia in a different order depending on randomization. Parameters measured were the patients' preference for topical lidocaine gel anesthesia or injection anesthesia with articaine (primary efficacy criterion), their maximum and average pain, and their intensity of numbness as well as experience of side effects; the probing depth; and the dentists' preference and their evaluations of handling/application, onset and duration of anesthetic effect, and patient compliance. RESULTS: After having experienced both alternatives, 58.3% of the patients preferred the topical lidocaine gel instillation into the periodontal pockets. The safety profile of the lidocaine gel differed positively from the safety profile of articaine injection in type and frequency of adverse drug reactions. The dentists' acceptance and preference regarding either anesthetic method studied were balanced. CONCLUSIONS: Instillation of lidocaine gel into the periodontal pocket is a preferred alternative to injection anesthesia for most of the patients and an equivalent alternative for dentists in nonsurgical periodontal therapy.