The random allocation method in this study will be the permutation block randomization method, in which "A" represents the intervention group receiving one (no lidocaine), and "B" represents the second group receiving lidocaine 2%. Slow. And "c" represents the third group with a low concentration of cocoa and "D" represents the group receiving the high concentration of the drug. This method is based on 9 blocks in 24 permutations, taking into account all possible displacements (ABCD, ACBD, ABDC, BACD, ....) and assigning zero to 24 (according to random number table) to each of these .displacements. , Runs (ABCD code 0, ACBD code 1, CABD code 2, ... up to 24)
Then, using a random number table, 9 random numbers (rows or columns) are selected and the permissions assigned to each number are written. (Arrange the permutations side by side, left and right, respectively) and how to assign 200 people to four groups of A B C D