Concern with Nitrous Oxide

My 9 year old son had some dental work done a few days ago.  He had 5 fillings on one side of his mouth.  They used Nitrous Oxide and said that he should be totally relaxed and do just fine.  3 of my other children have had nitrous oxide for fillings and did just fine.  However my son vomited a lot during the procedure.  Which they immediately extracted with their suction.  In looking this over at information online, I have seen it say that this occurs when over sedation occurs.  My son remembers that he vomited, but what bothers him most is he said he was so dizzy and felt like he was spinning the whole time.  And that he was in a inclosed small space the whole time.  So I'm assuming he was claustrophobic.  He has to go back to get a few more fillings, and I'm wondering if he should not have the nitrous oxide?  Is this common for someone to vomit during the procedure when having the laughing gas?  My other concern is if he doesn't have it, and he starts to gag or vomit that he'll freak out if he isn't lightly sedated.   My most important thing now is I want his next visit to go well, so this image doesn't stick with him.  I want to make sure he has a good experience, so he knows it always wont be so bad.  I wonder if he should have a sedative first, and no laughing gas, and maybe just do a little of the work, and go back a couple more times instead of trying to get everything done next time.   Any advice would greatly be appreciated.  Thank you!

[Jerome Bogin, D.D.S.]

I am of the opinion that a child should be trained to accept dentistry with local anesthesia(injection).I think most children can accept the treatment if enough time is spent with them, having patience and caring. If this is not possible then I think a specialist is in order. The answer to your question is yes ie the vomiting when receiving nitrous. I think I would be concerned that it might happen again and would consider alternative methods to having your son treated.