Let your children pick their own toothbrush when it’s time for a change. This gives them something to look forward to every three months. Today, there is an assortment of kiddy toothbrushes from familiar cartoon characters to those in the shape of animals like penguins or cats that will make toothbrushing a lot more fun. In choosing a toothbrush, make sure it has soft bristles and a head that fits well in the child’s mouth. Manual and electric toothbrushes are equally effective at removal of dental plaque.
17 months is still a little young. Give them those teething toothbrush for him to play or chew on. soon he will get and understand to concept of brushing teeth with a toothbrush!
Hey.. this article may be helpful https://sg.theasianparent.com/kids-hate-brushing-teeth
Use flavoured toothpaste, he may not bite it.