Early Bone Loss/Remodeling?

Hello. I placed an Neodent Grand Morse implant 4.3 x 10mm in a completely healthy patient. The surgery went uneventfully. The implant was placed at bone level 3 months after extraction. 3 months later. I placed a crown over a 1.5mm height TiBase. I checked up on him 6 months later. The site looks healthy, without pockets nor bleeding. I took an Xray and could see some bone loss of the first threads of the implant. Patient doesn't complain at all. Should I be worried about it? I'm guessing maybe low TiBase Height? What are your thoughts?

Anguswalk DDS comments:

The crown to implant surface area ratio seems to be inadequate for the occlusal forces this patient generates. Flexure of coronal bone has lead to vertical bone loss. Left alone this will ultimately fail on its own. Replace with a wider longer implant now or later. The situation is not too difficult but requires delicate handling for the patient. All the best.

PK comments:

My guess is biological width. Depending on the original tissue thickness the implant may have needed to be subcrestal

Jason Larkin comments:

Neodent implants need to be placed 2mm subcrestal. This will allow you to use the taller gingival height tibases to allow for biological width of thick tissue around top of implant. Other factors could have been thin buccal plate, maybe waiting 4 months after extraction to allow for more complete socket remodeling, high occlusion or excursion, slight tissue opening prior to 2nd stage surgery. I feel the implant is fine as long as you have thick tissue and no lateral occlusion. ISQ? My 2 cents for next time is to place subcrestal 2mm. That's what the Neodent deep morse taper connection is know for.