IRCT2017101036699N1 IRCT 2017-11-13 Vice chancellor for research, Tabriz University of Medical Sciences Comparing of the efficay of Articaine and Lidocaine on Anesthesia of Maxillary first Molars in 4-6years old children Comparison of anesthetic efficacy of 4% articaine and 2% lidocaine for maxillary primary molar buccal infiltration during routine dental treatment in 4-6years old children 2017-11-22 anticipated 74 Complete https://irct.ir/trial/27360 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Not used, Assignment: Parallel, Purpose: Other. N/A Local anesthesia. Intervention 1: In group 1, an infiltration with articaine 4% with epinephrine 1 /100,000 will be informed as following.The syringe is parallel to the longitudinal axis of the tooth at the depth of the buccal mucosa groove and Up to reaching the tip of the needle into the apex of the buccal roots of the first molar will be drowned, Then in about 30 seconds, about two-thirds of the carpul (1 ml) will be injected. After 5 minutes the treatment will be done. It should be noted that injections and all operations will be performed by a same pediatric dentist. Intervention 2: In group2, an infiltration of lidocaine 2% with epinephrine of 1/1: 80000 will be informed as following. The syringe is parallel to the longitudinal axis of the tooth at the depth of the buccal mucosa groove and Up to reaching the tip of the needle into the apex of the buccal roots of the first molar will be drowned, Then in about 30 seconds, about two-thirds of the carpul (1 ml) will be injected. After 5 minutes the treatment will be done. It should be noted that injections and all operations will be performed by a same pediatric dentist.