There are some basic universals that all people want to know before they engage in an activity. When these basics are accounted for routinely and followed through with, it can go a long way toward building trust and competence.
1) Where am I going and why? ~ give him specifics about where he is heading, "Let's go to the bathroom so we can brush teeth."
2) What am I doing? What is my job while we are there? ~ give him a role such as "You be the brush holder first and then I will take a turn."
3) What will happen next (after we are done)? ~ let him know the first - then pattern of what will be happening so that he can begin to learn it won't take forever and he will be able to get back to what he wants to do. "First we need to brush teeth. Then you can go back to play in the playroom."
4) How long will it last? ~ give him a framework to think about how long it will last, even if we don't know for sure that he will understand exactly what that means. It is more about the habit and verbal pattern of information. For example, "you brush for 5 and then I will. 5-4-3-2-1 , Great! Now my turn, 5-4-3-2-1. So clean! We are done."
5) Say what you mean AND mean what you say ~ As you are building this routine, you will want to stick to whatever you say, regardless of how it is going. As you are setting the routine for yourself and the child, you will want to resist the urge to "push him" if it is going well. While this is good for getting more teeth brushed in that moment, it undermines your overall goal of having his teeth brushed consistently because you didn’t do what you said you were going to do, and that goes toward him not being able to believe you. Conversely, if it is going really rottenly, try to stick with it and follow through, but make an adjustment next time. For example, if you realize that count of five just never goes well, try to drop it to three and see if that helps.
A teeth brushing interaction could look like:
1) "Hey Buddy, we are going to the bathroom to brush teeth." Hand extended. Wait for him to take your hand, possibly up to 30 seconds, before gently reaching for his hand and guiding toward bathroom.
2) "You will hold the brush while we count."
3) "First brush teeth, then back to play with lion."
4) "I will count 5 for you and 5 for me. 5-4-3-2-1 and 5-4-3-2-1"
5) "Way to go! You were a good helper with your teeth. You can go find lion. I bet he wants to smell your yummy breath."
When we fill in the blank of those questions ~
Where am I going?
What is my job/role?
How long will it last?
What is happening next?
Everyone feels more comfortable and competent and likely to be successful.