My boyfriend is cambodian and most of his family has bad teeth?

some are rotten or discolored. his four year old daughter has many cavities and her baby teeth are rotting. in the nicest way possible, is this a genetic thing? i have noticed many asians with bad teeth. is this a result of poor diet? i heard that they feed babies sugary condensed milk? im just worried because we are expecting a baby that will be mixed puerto rican /black and half cambodian. he has told me that most people dont care about dental care in cambodia because they are so poor but, i have noticed many asians born in america have bad teeth too.