IRCT20171106037264N2 IRCT 2018-09-18 Tehran University of Medical Sciences Pain reduction by Laser Pain reduction during infiltration injection of maxillary deciduous molar teeth by low level laser in 4-9 years old children 2018-09-23 anticipated 64 Complete https://irct.ir/trial/32538 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Parallel, Purpose: Supportive, Randomization description: This research is randomized clinical trial.with the help of 4 numeric random blocks ,by Excel software, Blinding description: The participant, care provider,investigator and outcome assessor will not be informed about the application of laser which is on or off. 3 Pain reduction during infiltration injection of maxillary deciduous molar teeth by low level laser in children. Intervention 1: Intervention group: In referral session patients history will be taken and intervention's goal will be explained to parents then an informed consent will be taken.First,20% benzocaine local anesthetic gel(Brand: pahl) will be applied to the subjected area.Right after, Denlase's low level laser (wave length 810 nm, by hand piece therapy( 0/78 cross section) 200 mW power, 20 s Radiation time,5j/cm2 density of energy) will be applied to the area for 20 s before injection. This steps will be done once for buccal side and once for palatal side. Intervention 2: Control group: In referral session patients history will be taken and intervention's goal will be explained to parents then an informed consent will be taken.First,20% benzocaine local anesthetic gel(Brand: pahl) will be applied to the subjected area.Right after, Denlase's low level laser, wich is on off mood will be applied to the area for 20 s before injection. This steps will be done once for buccal side and once for palatal side. Undecided - It is not yet known if there will be a plan to make this available Justification or reason for indecision in sharing IPD is There is no further information