I can't really answer your question, as I chose not to night wean. I felt that our dd's mental health was more important than the baby teeth, which will come out anyway. Also, I was not convinced that night nursing was to blame, really.
The dentist advised me to wipe dd's teeth with a piece of cloth after each nursing. Not exactly possible as we would have had no sleep. Hah. Instead, we had her rinse her mouth after each time she ate food and also had her take xylitol. We also had never fed her juices and limited fruit, etc.
The end result, who knows why, was that her teeth looked scary and the two front teeth crumbled into pieces and she was left with little stubs, one of which was dark and hollow. After one who wanted to fill her mouth with fluoride every month or two and predicted needing to fix the teeth under anesthesia, we found a dentist who was happy to just keep en eye on things. After some years of visits, we agreed to an x-ray to check how soon the permanent teeth would come and how they were doing. Everything was ok. Last time we went she was amazed with the end result: Dd is now 6 and has lost 3 teeth by now. Meanwhile, nothing bad has progressed for quite some time. The teeth look just as scary -or good from my point of view- as they did some years ago. Dd never had any major pain caused by her teeth, which would be hard to believe if you had seen them.
I don't know that I can really give advice to anyone else. However, we are so very pleased with how everything turned out. Dd loves going to the dentist, as nothing was ever done against her will and the dentist was very nice and respectful.