Recurrent Infection after Implant Surgery: Causes?

Dr. R. asks:

Four weeks ago I installed an implant into #18 area [mandibular left second molar; 37]. The bone type was type II -III. Two weeks following the surgery the patient presented with a fistula to the coverscrew area. I exposed coverscrew checked for mobility of coverscrew which had none and detoxified with tetracycline. I tried to leave the coverscrew exposed. I placed the patient on antibiotics. But, 2 weeks later the gingiva grew back over the coverscrew and the fistula was back. I exposed the coverscew again and again detoxified.

I realize now that I probably should have placed the healing abutment on at the 2 week time frame. Could this have caused the infection? From my understanding, if the implant is in softer bone, it is not recommended to remove the coverscew at this time since it may cause the implant to back out. That was my premise, at least, and the reason why I did not remove coverscrew at the 2 week mark. In general, what is the time frame that is recommended?

One other point that may be significant is that at the time of the initial surgery, the coverscrew fell down and it was replaced with a cover screw that had been used previously but had been cleaned and autoclaved. Could this be a factor? What do you recommend at this point?

6 thoughts on “Recurrent Infection after Implant Surgery: Causes?

  1. An xray would have been nice.

    What could be happening is not coming from the implant site, but from an adjacent tooth. What do you have? Do you have a root canal tooth next to the implant? Is there a tooth next to it that is non-vital?

    I don’t have enough information to give you an answer.

    As far as cover screws..sometimes they aren’t placed completely and food gets in between them and the implant..but then again, I don’t really have enough information. If you can provide it for us that would be great.

  2. Does the x ray show a radiolucency or significant loss of bone? If so then remoe the implant, debride the osteotomy and start over again. If the x ray is relatively normal then place a healing collar and observe. If symptoms and or a fistula occur then remove the implant. Usually fistula formation means a failing implant. The usual reasons for failure: over heated bone, inappropriate osteotomy such as a significant dehiscence or perforation,or as mentioned above possibly infection from an adjacent tooth. Implant placement in a site previously occupied by a tooth with significant apical pathology will sometimes result in post op infection soon after the initial antibiotic prescription is finished (i.e. 2 to 3 weeks after surgery).

  3. More info. Would be nice. The implant is infected. It may resolve spontaneously. What are you doing with the topical abx? Just watch and cross your fingers. The patient needs to be on an po abx. . If there is purulence ,something is gonna give! If the cover screw was down ,sterilized and compatible, it’s not the source . Bv

  4. is it oozing wid pus???
    Did antibiotics make any change???
    Many times the fistula at the top is because food getting stuck in the slot for key in cover screw… Try curretting it only..ask patient to brush hard the ridge area from above…shud help…if it stays perpetual..than u r probably heading for a failure…!!! The volcano is deeper…inside… !!!
    B.o.l

  5. Dr R.
    I wouldnt get overly concerned at this point. I saw no mention of pus/exudate in your post and I suspect it looks fine radiographically. I usually place a healing abutment on immediately with excellent success and have only limited experience with healing caps, that being said I have had a least a couple where the healing cap became exposed and the case turned out completely fine. I think you made the right decision by not switching to the healing abutment at 2 weeks. that is pretty much the weakest it will ever be and you absolutely could have backed the implant out. I would wait a month, trim the tissue, and if everything looks good and the implant is immobile, remove the healing cap and place a healing abutment with gentle to moderate finger pressure. Good luck with what ever you do.

  6. Dear Dr. R, do a fistulography with a gutapercha point number 20, so you can do the correct diagnosis.
    Good luck.

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