Rough Surface Exposure after Immediate Implant

Sixty-eight year old healthy man has had multiple implants.  He readily accepted immediate implant when the tooth #5 had subgingival fracture of the lingual cusp (Fig.1).  A 5x20 mm Tatum screw implant was placed immediately after atraumatic extraction and bone expansion (Fig.2 I).  Implant rough surface was exposed buccally and lingually when the implant was placed equigingivally proximally.  Two buccal accessory incisions were made.  The flap was raised with scoring the periosteum underneath, advanced downward (as shown in Fig.3 arrow) and sutured to the lingual papilla.  The buccal aspect of the implant is covered, whereas the lingual rough surface remains partially exposed (Fig.4 arrow), assuming that the palatal mucoperiosteum is tough to advance even with release incisions.

Fig.3 and 4 are taken 1 week postop, whereas Fig.5 and 6 (mirror view) are taken 2 weeks postop. 

Fig.7-9 are taken 3.5 months postop.  Buccal gingiva appears to have elevated (Fig.8 arrow, as compared to Fig.5 B).  The rough surface seems to have been partially covered by lingual gingiva (Fig.9 arrowheads, as compared to Fig.6).

My questions are as follows.

It appears that exposed rough surface causes no harm.  Can the lingual margin be placed on the smooth portion of the implant when prepared for crown?  Or does the rough surface need to be covered by crown?

How to handle the lingually exposed rough surface intraop for immediate implant?  Guided bone regeneration?

Hello Dr. Wei,   You may recall, I said I always prefer to place an implant at the time of the extraction . In order to prevent the exposure of threads you must cover any exposed threads at the time with a graft material and then have primary closure by movement of crestal soft tissue. I preferred using Biogran as the graft material. Now that healing has taken place and threads are exposed, I would prefer to remove the exposed threads and prep the implant to the bone crest on my abutement.  If the threads are left exposed the bacteria will have a path (along the thread) into the bone.  Dr Borgner 11/13/2011

Dear Dr. Borgner: Thank you very much for the reply, which is very helpful.  In fact, after studying Tatum implant design, I found out that only the rough surface of screw type implant is exposed lingually (~1 mm), not threads.  Does crown still need to cover the rough surface?  The rough surface can also trap bacteria?

Dr Wei,  Rough surface exposure is not as important, I would polish the exposed surface with a polishing wheel when prepped. It looks like the implant has healed well.  Dr Borgner 11/16/2011


Xin Wei, DDS, PhD, MS 1st edition 11/12/2011, last revision 09/19/2012