In this study, the anesthetic efficacy of articaine infiltration technique with lidocaine inferaalveolar nerve block technique in pulp therapy of lower primary molars is compared. This article is a randomized, triple-blind crossover study without control and placebo and the study group is four to ten years old healthy children who need bilateral lower primary molar pulp therapy or deep restoration. Among these, children who have good cooperation are included, but children who do not cooperate are excluded and For this purpose, 64 children are enrolled in the study. Children are randomly and equally devided into two groups, A and B and they are treated within two sessions and in each session, one lower primary molar pulp therapy is done. Group A, in first session receives lidocaine infraalveolar nerve block injection and in second session receives articaine infiltrarion injection. In group B, all the procedure is the same as group A, but this group in first session receives articaine infiltrarion injection and in second session receives lidocaine infraalveolar nerve block injection. Also the washout period is one week. In each session, at the moment of pulp exposure, the child will be asked to mark visual analuge scale according to his pain. If the anesthesia caused by articaine infiltrarion injection is equal or better than lidocaine infraalveolar nerve block injection, due to greater ease and lesser risk, it can be the choice injection in pulp therapy of lower primary molars.