Can I just wear the denture over the healing caps without having abutmentss?

Well, you can but you won't get the full benefit of the implants. Furthermore, the healing caps will eventually unscrew and fall out. You could lose them and the gums will grow over the implants further necessitating another minor surgery to uncover the implants and more costs for new healing caps. It's not the way to go and your should reconsider and get your implant restored properly. 

You can´t. without abutment your teeths will not have a retention. Healing caps are not tightened. Implants are supposed to be permanent and thats why it can´t be possible. If you want to have your teeths receiving their benefits, just wear your abutments.Good luck!

You may certainly wear the denture over the healing caps, but that will not provide the retention or stability that regular abutments will offer. Also, healing caps are not tightened as much as regular abutments as they are supposed to be temporary caps- hence they can become occasionally loose. It is best to have regular abutments placed so you can enjoy the benefits of your dental implants.