Newbury, United Kingdom
Clinical case description:
A 58 year old female presented with an upper right central incisor that required extraction. This tooth was heavily restored with a post and crown and a CBCT scan confirmed the presence of a large periapical area and absence of the majority of the labial plate. The patient was healthy and a non smoker.
The treatment plan would require a staged approach including removal of the tooth and the periapical granuloma. In this instance it was also determined to rebuild the lost bone volume with a bone substitute material at the same time as tooth removal. The rationale was that if the tooth was removed as a singular procedure, then the likelihood of significant collapse of the site (following post extraction healing) was a tangible risk which could jeopardise implant placement at a later date. In such a scenario, a separate large bone grafting procedure may be required at a later date leading to the necessity for a further surgical procedure for implant placement. By grafting the site with a bone substitute material at the same time as tooth removal, it was hoped that the overall socket dimensions could be maintained optimising the site for straightforward implant placement in due course.
The tooth and granulation material were removed resulting in a bone defect which extended to the nasal floor. The palatal cortical plate was visible although intact. The socket and bone defect were filled with Geistlich Bio-Oss® particles (0.25mm-1mm) and extending on the facial surface to re-establish the original labial plate contours.
A collagen membrane (Geistlich Bio-Gide®) was inserted between the palatal socket wall and the palatal gingiva and wrapped over the crestal area onto the buccal aspect. A double Geistlich Bio-Gide® membrane was subsequently placed to cover all the bone graft material. No fixation pins were required. The buccal flap was sutured back to closure with no attempt made to coronally advance the flap. As a consequence, the crestal portion of the membrane was left exposed to the oral environment (open wound healing). Finally, the site was temporised by utilising the adjacent upper right lateral incisor as a bridge abutment.
Epithelial coverage over the membrane and underlying bone graft occurred by secondary intention and the six month review revealed a typical convex buccal contour and a CBCT scan confirmed the presence of the Geistlich Bio-Oss® graft and a favourable volume of bone.
Following flap elevation, it was evident that the overall dimensions of the socket had been maintained with minimal dimensional shrinkage and subsequently implant placement was straightforward without the need for further bone grafting. Excellent primary stability was obtained. After a further three months, prosthetic reconstruction was initiated beginning with provisionalisation and subsequently restored with a zirconia abutment and e.max crown.
This case study demonstrates the success of the open wound healing concept whereby the assimilation of a particulate bone graft was not impeded or compromised despite the fact that primary closure of the soft tissues was not achieved. In this respect, coverage of the open wound with a Geistlich Bio-Gide® membrane may be an important factor in early protection of the bone graft and favours rapid epithelialisation of the wound by secondary intention.