Assuming all metabolic/systemic factors were taken into consideration pre-op:
A. Did the bone overheat due to lack of irrigation during osteotomy?
B. Was the implant over torqued during placement?
C. Merely irrigating the site after failure of osseo-integration is inadequate, the site has to be inspected for granulation tissue/ epithelial invagination, curetted, preferably grafted, and left alone for 8 weeks at the minimum before re-accessing for implant placement.
D. Was there an inadvertent load on the implant post placement?
E. Was the implant drill blunt, which might result in play in the implant post primary fixation.
F.When you say infection-free, how did one ascertain that there was an infection? Was there granulation tissue, discharge inflammation etc etc.
G. What is the quality of bone at the site?
F. Was there a cratering or loss of the crestal bone post primary fixation, which is the first sign of osseo integration failure.
These are a few thoughts off the cuff… open to interpretation.
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