Give him bottled water w/o fluoride
.Wean to an open-mouthed cup with 2 handles. Limit milk/milk products to 16-21 oz./day & juice/ sweet drinks to 0-4 oz./day with meals & snacks, followed by toothbrushing. Have a consistent bedtime & routine. Read, soothe & brush his teeth. Put him in his own bed drowsy, but awake, to self-calm to fall asleep.