Four months after graft: type 5 bone at lingual site?

Hounsfield units score depends mostly on a scan technique and does not reflect an actual bone density level. How about clinical stability of the implant and the lingual probing depth? X ray shows an empty space there.

Looks like there is no bone there, based on the images you posted

I may be missing something but If this is an analysis of a future implant over a current scan then it appears that you have a void in the bone that is well circumscribed . Could you just post the segments of the scan without the implant in place-that may help us see better. The buccal looks worse than the lingual visually Ive looked baack and forth several times and it all looks like empty space- if that is the case I would love to hear about how you did the graft and when relative to the extraction. If there is bone there then nevermind any of this

Just as a suggestion... Next time you extract a tooth, consider using the tooth itself as the graft by converting it into autogenous Dentin Graft. Perfect results every time. You can do it using the Smart Dentin Grinder. Takes about 10 - 15 minutes. The patient will also react very positively to this procedure.

It looks like the extraction site was mostly a shell of cortical bone which has low vascularity hence low bone turnover for your graft. If you want a more dense bone wait longer 6-8 months. In the future if you use 50% cancellous and 50% Xenograft ( or 50 % Cortical bone).

Could you anesthetize the area and sound for bone with a probe?

Buccal looks much worse than lingual. Sure you're reading your scan correctly?

I always say the only way for the bone to regenerate is for the Host biology to do it , simply we can integrate foreign materials into host bone to "improve" the appearance but true regeneration is done by the host . So we new to work with the host , hence the less I do the better the outcome will be long term as we are dealing with a living tissue and need to keep it that way . So BTcP sounds good as it will fully resorb in time with host regeneration . Regards