Immediate Placement of Dental Implants in Infected Dental Extraction Sockets

Osseointegration is defined as a direct structural and functional connection between living bone and the surface of a load carrying titanium implant¹. Osseointegration is when there is no progressive relative movement between the implant and the bone with which it has direct contact. Using this concept, implant placement in infected sites has previously been contraindicated.

We present a study of 85 consecutive patients (98 implants) treated over a 1-year period receiving immediate implant placement. Cases were selected based on radiographic and clinical evidence of periodontal or periapical infection preoperatively. All the implants were placed by a single operator and followed up for at least 12-months.

All patients were given a chlorhexidine mouthwash rinse for 2-minutes prior to surgery. No preoperative antibiotics were given. After administering local anaesthetic, periotome was used to separate the periodontal ligament from the tooth prior to delivery with forceps. Following extraction, curettage of the socket was conducted until visible granulation tissue was removed and bone contact obtained, coupled with copious saline irrigation. Sockets were then soaked with an antibiotic solution for 1 minute using ribbon gauze. Osteotomy site was prepared using the nobel drill sequence up to 1 mm less than the implant diameter and extending 2-3 mm past the apex of the socket. Any bony defect around the implant was repaired with xenograft bone graft (Bio-Oss®). If a flap was raised during surgery an additional haemocollagen membrane was placed prior to replacing the flap. Primary implant stability equal to or greater than 30-Newton was established. Hand torque was applied to obtain increased stability and greater bone compression if the bone quality permitted. Either a healing abutment or provisional prosthesis was placed.

All patients were prescribed 500mg Amoxicillin TDS and 400mg Metronidazole TDS for 5-days postoperatively. A daily Chlorhexidine mouthwash was recommended for 14 days. Normal oral hygiene procedures and analgesia were advised during the healing phase.

Initial follow-up was arranged 2-3 weeks postoperatively. After 6-8 weeks a definitive restoration was placed. A final review at 12 months was arranged before discharge to their referring general dental practitioners.

Survival criteria included fulfillment of designated function (occlusion and aesthetics), stability, absence of pain or clinical signs of infection and no radiographic signs of peri-implant pathology. Data collection included the age and gender of the patient, the site of implant placement, implant size, socket graft and time of loading.

The study found 94 (95%) of the 98-implants placed had survived. In the immediate loaded group, 39 (95%) of the 41-implants placed had survived based on clinical and radiographic follow-up. Age and implant survival highlighted the 80-years and over category where 2 (33%) of the implants had failed. All implant failures were reported in females. No significant differences were noted between maxillary and mandibular placement or size of implant.

Survival of early and immediately loaded implants placed immediately following tooth extraction at infected sites has been demonstrated at 12 months. However, the survival of implants in infected sites depends on obtaining good primary stability on implant placement and meticulous debridement of the infected site. The use of antibiotic irrigation of the site may be a contributory factor in eliminating the main source of infection and encouraging regeneration. An appropriate xenograft is effective for guided bone regeneration and good oral hygiene will also influence the success of the implant placement.

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References:

1. Brånemark P-I et al. Osseointegrated implants in the treatment of the edentulous jaw. Stockholm: Almqvist and Wiksell 1977:132.
2. Lindeboom JAH et al. Immediate placement of implants in periapical infected sites: a prospective randomized study in 50 patients. Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontics 2006;101:705-710.