Steps to Close Fistula Associated with Immediate Implant
Prior to surgery, an apical fistula is found associated with the discolored upper left central incisor (Fig.1 <). Pain has improved reportedly since taking Amoxicillin for #14 implantation. Note that the gingival margin of the affected tooth is higher than that of the right central. In spite of loss of the buccal plate, there is no clinical sign of collapsing pre- and post-extraction (Fig.2,3 *). A large periradicular radiolucency (Fig.4 arrowheads) is confirmed with a 2 mm pilot drill in place (20 mm deep from the gingival margin). A 5x20 mm implant is placed with insertion torque >60 Ncm (Fig.5 I), with mixture of autogenous bone, allograft and synthetic bone filling the defect (*). Prior to grafting, perio glue is used to seal the fistula (Fig.6 >) and a piece of collagen membrane is inserted immediately lingual to the defective buccal plate (Data not shown). Following placement of a 20º 4x5 mm abutment (A) and preparation and fabrication of an immediate provisional (Fig.7 P), another piece of collagen dressing (half moon shaped) is inserted into the remaining buccal gap (Fig.6 *). In order to let the recessive gingiva (Fig.7 <) grow down naturally postop, the margin of the provisional is intentionally trimmed short.
In brief, several steps must be carried out strictly to close a fistula associated with immediate implant: oral antibiotic peri-surgically (1); thorough debridement of and topical application of antibiotic to the socket post extraction, placement of collagen membrane inside the fistula prior to bone grafting, sealing the external opening of the fistula and finally packing the remaining defect with bone and membrane.
The patient returns 2 months postop. There is minimal buccal plate atrophy (Fig.8 arrowheads) over the immediate provisional (P). The gingival margin of the left central incisor appears to have grown coronally (Fig.9 black <), while the fistula has regressed (white >). The bone density around the implant appears to increase 2 months (Fig.10 I) and 7 months (Fig.11) postop.
There appears no bone loss (Fig.11 *) or papillary recession (Fig.12 *) 7 months postop. The implant/abutment is re-prep for final restoration (Fig.13,14).
It appears that the fistula, although reduces in size, remains with light exudate (Fig.16 <). When a Gutta Percha is inserted into the fistula (Fig.15 >) before crown cementation, it points to the original mesial socket with possible foreign body (*, which may be related to apicoectomy). If the fistula gets worse or become symptomatic, closed debridement with Arestin placement or open debridement will be performed.
In fact, the fistula remains with minimal exudate, 8.5 months post cementation. Open debridement is performed, followed by bone graft with PRF (Fig.17). The wound seems to heal favorably, 1 week postop (Fig.18). The incision is somewhat small, barely covering the bony defect. It appears that PRF helps prevent wound dehiscence.
The patient remains asymptomatic 7 months post regraft. There is apparent bone growth (Fig.19). A small piece of graft is found attached to the gingiva (Fig.20 <). In contrast, a delayed implant of the same patient is associated with pre- and post-implantation bone loss. There is minimal crestal bone loss 2 years 3 months post cementation (Fig.21). Panoramic X-ray is taken 3 years 4.5 months postop cementation. CT taken 3 years 10 months post cementation shows the intact buccal plate (Fig.22,23 B). The apparent thread exposure shown in 3-D image (upper left of Fig.22 *) is due to low bone density in the axial section (upper right of Fig.22 *).
Upper Incisor Immediate
Xin Wei, DDS, PhD, MS 1st edition 12/07/2014, last revision 05/11/2019