A method of anesthetizing a tooth requiring tooth preparation, caries removal or manual manipulation thereof is disclosed. The method includes the steps of applying a composition having a high concentration of potassium to the tooth requiring tooth preparation, caries removal or manual manipulation, the composition being adapted to anesthetize the tooth so that the tooth may be drilled or manually manipulated, whereby the potassium enters the dentinal tubules and odontoblastic fibrils and penetrates the pulpal tissues of the tooth for anesthetizing the tooth. The improvement consists essentially of applying a solution of EDTA, EGTA, and citric acid to the tooth before the application of the potassium composition, the solution of EDTA, EGTA, and citric acid effectively removing a smear layer from the tooth so as to facilitate the penetration of the potassium solution through the dentinal tubules and odontoblastic fibrils.