It's really important to prevent this gorgeous pearly teeth children have and establish good habits from an early age. We started brushing Jacobs teeth at the age of 4 months before his first teeth came out. We were using a bendy brush just to make him used to brushing and to clean his gums. We started brushing his teeth with a proper toothbrush and toothpaste at the age of 6 months and we do it twice a day.
He absolutely loves to clean his teeth. Just have a look at this video :)
And that's his first toothbrush.