All potty training books and articles I've read say that most kids potty train at different times for day and night; I've also observed that with my children, who did wear pull ups at night for a while and didn't wear them during the day and potty trained ok during the day. Note: the younger was dry at night at between 3 and 3 1/2 and the older one still wears pullups and wets almost every night at 5 1/2, but is fully potty trained during the day. Different kids train at different times, so don't feel like your child has to be potty trained by 3 or 4 or 5 -- it will happen when your child's body is ready. (I think doctors start getting concerned about night time wetting at around age 6 or 7, something to ask the pediatrician if you have concerns.) It's a different process for each child, in part because their bodies have to be ready and nothing you can do can make their bodies develop faster; I learned the hard way that the more you stress and fret about it and the more pressure your child feels, the harder it is. So as long as your child is comfortable with it, give yourself a break and go for the pull ups at night. I would just think about how you approach it, because he might feel relieved or he might feel criticized or ashamed to go back. My sons would have been happy, but my friend's daughter did not want pull ups AT ALL once she stopped wearing them during the day, even though she was wetting every night. (The mom got one of those water-proof things that go over the sheets to cut down on some of the laundry/full out midnight bed changes.) Something to be prepared for, both of my children trained faster with peeing than pooping, which was very pronounced with my older son, who would hold BMs until naptime, when he got pullups and then relieved himself; when he stopped napping and was just using pullups for BMs, we stopped them and then he held until evening and would soil almost as soon as we put the pull ups on him! Finally, I made the rule that he could go in the pull ups but had to be sitting on the potty or toilet when he did to get him accustomed to the routine of going in the bathroom on a toilet and then it was just another step to remove the pullups. But he was fully daytime potty trained by 4, so again it does eventually happen, we parents just have to be patient with ourselves and our kids! I highly recommend Pantley's "The No-Cry Potty Training Solution" for great ideas and advice, especially how to create the right potty training approach for your family.
Hope this helps!