Predictability of GBR?

Dr. H asks:

I am periodontist with two years experience with dental implants.
Recently I placed implants in a 36 year old female,healthy, with no
parafunctional habits, who had lost tooth numbers 19 and 30 several
years ago. She has buccal-lingual bone resorption, so I decided to
place the dental implant and do guided bone regeneration (GBR) at the same time.

I used a bioactive glass (fillerbone) and a membrane (Membracel). During the healing process, the flap opened exposing the membrane and the graft which eventually was lost, leaving an exposed dental implant. I waited for the healing process to close the wound completely before taking a course of action.

Two months now since the surgery and there is a complete closure of the wound, leaving only the head and the cover screw exposed. The patient has shown excellent oral hygiene and has followed all the indications given (eg, brush gently, with a gentle toothbrush with a .20% chlorhexidine gel).

My questions are: Should I try to regenerate again or can I load the dental implant knowing that I have at least a 30% vestibular dehiscence on the implant? Lingually, there is no implant bone defect. Will I have tissue problems, especially plaque control, and how predictable is GBR after the implant has osseointegrated? How can I be sure that I have a “tension free” flap, which is, I think, is my biggest problem?