The risk of infection starts when a periodontal pathogen gets released (from the teeth) into the mouth cut. Risks are lowered with a good cleaning 3 months prior and meticulous dental hygeine prior to surgery and more so than 'normal'. So, decreasing risk, starts there.
On the day of surgery, a patient should be instructed to self clean the mouth (brush teeth and disinfect mouth wash) soon before it while at facility where surgery is to be performed. After that, right before the cut, the doctor should lavage the mouth with more anti-septics, like while one is on the table.
My readings/research on infection risks with porex implants is LESS than 5%. So, 10% chance seems pretty high to me. However, the 10% could reflect that observed in the clinical practice who cited that figure. Still seems high to me and enough so NOT to place implants in at the SAME time as a cut to the bone area because if there is infection to implant AND a cut bone area, risks of infection would tend to get higher to the bone cut areas .
Keep in mind that even if just bone cut and no implant, having no implant does not preclude infection. Although if infection and no implant, the chances are better of the infection clearing with no implant placed at same time as bone cut area.
Then there is factor of pore size of implant. I forget the micron size but it's like this. A phagocyte is LARGER than an unwanted bacteria. (Phagocytes are cells that protect the body by ingesting (phagocytosing) harmful foreign particles, bacteria, and dead or dying cells.) So, the pore size must not be that small so only the bad bacteria can get in but not the phagocytes to ingest (protect against infection).
Probably best to get them out ASAP to lower chances of infection spreading to bone.