What is going on with my son?

My son is 11 months, he'll be one on the 24th. For the past couple of days he has been spitting up a lot. He was diagnosed with reflux when he was 6 weeks old but the symptoms disappeared when he was 9 months, so I took him off the Zantac. He isn't arching his back when he eats his bottle and it doesn't seem to bother him when he spits up. He is teething, he actually has 4 teeth coming in on the top, can this cause babies to spit up? Can reflux disappear and then suddenly reappear later? I'm worried about him because it seems like he is spitting up everything he eats, not just formula, but the solids he eats too. Any advice would be appreciated. Thanks.