Treatment of Early Developed Peri-Implantitis in Fibula Graft Site.

The fibula microvascular free flap technique and placement of dental endosseous implants seem to be viable options for reconstructing the mandible, following a resective jaw surgery. The causes of early failures of implants include bone overheating, latent infection by surgical trauma, the factors related with the implant, and overcompression. This case report reviews the mechanisms of early post-implantation bone loss, and suggests the course of treatment for early peri-implantitis for implants that show no mobility. Radiographs and clinical data presented have shown that the surgical treatment of early developed peri-implantitis using GBR methods in free fibula graft sites offers promising and stabile results.

Introduction

In the past 25 years, the fibular microvascular free flap technique has become a routine procedure for the reconstruction of the mandible, in order to correct defects of the bone caused by the resection of the tumor. The literature data show that bone grafting and placement of dental endosseous implants seem to be widely accepted treatment options for reconstructing the mandible, following resective jaw surgery ().

Long-term studies show that the survival rate of implants placed into the fibula is acceptable ().

Early failures of implants are defined as those occurring between first and second-stage surgery, and the causes include bone overheating, latent infection by surgical trauma, the factors related with the implant, and overcompression (, ). The early peri-implant changes, apparent on the x-rays around the implants that have not yet been loaded, suggest iatrogenic causes of rapid crestal bone resorption, due to various factors, such as pour indication, extremely hard and poorly vascularized bone, surgical trauma, lack of keratinized gingiva ().

The authors of this paper suggest that the course of treatment for these peri-implant early changes and bone necrosis around implants that show no mobility, even in the free fibula graft site, can be the guided bone regeneration protocol, with prior surgical debridement of granulation tissue and detailed cleaning of the implant surface.

It is now accepted that clinicians can try to regenerate the bone that was resorbed as a result of infection, following successful decontamination of the implant surface and bone defect. With the re‐osseointegration as the ultimate goal, a number of regenerative techniques have been introduced, and various success rates in the use of regenerative procedures have been reported, regardless of radiographic evidence of defect fill ().

As with treatment of peri-implantitis, the primary objective is the elimination of the biofilm from the implant surface, utilizing one of the various protocols suggested that include the use of antiseptics, antibiotics, air‐abrasive devices and lasers (). The use of laser for decontamination in surgical resective or regenerative therapies may lead to better clinical results than conventional treatment alone ().

The aim of this paper was to present the management of early developed peri-implantitis in fibula graft site by utilizing surgical protocol for guided bone regeneration and laser-assisted surgical debridement and implant surface sterilization.

Clinical presentation

Pre-implantation clinical findings

A 26- year-old male patient presented to the Department of Implantology, Clinic of Dentistry, following the resection of the right side of the mandible, and reconstruction with the fibular microvascular graft. The patient was referred to this department from the Clinic for Maxillofacial surgery, for the purpose of receiving dental implants in the fibular graft area, and complete prosthetic rehabilitation to replace the missing teeth and the supporting alveolus.

Discharge summary from the Clinic of Maxillofacial Surgery contained following information:

The need for mandibular resection was the recidivism of previously pathohistologically proven myxoma.

The course of maxillofacial treatment: First surgery: Resection of the right-side body and angle of the mandible, reconstruction of the defect with the fibular microvascular autotransplant, fixation of the fragments with mini plates, and rigid intermaxillary immobilization; Second surgery: A day later, due to the development of hematoma in the early postoperative period, revision and hematoma evacuation surgery with anastomosis revision was performed. The patient was treated with antibiotics, wound debridement was done regularly, and the patient was fed through the nasogastric tube; Third surgery: Eight days following the second surgery, a dehiscence of the intraoral wound was noticed, and a revision of the wound was performed; Fourth surgery: Due to the prominence of a part of the bone transplant, a wound revision with osteotomy of the part of the autotransplant was performed, 20 days after the last procedure.

The postoperative course was uneventful, with the administration of antibiotics and regular wound debridement. The wound healed per primam, and after the removal of the intramaxillary fixation, the range of mandibular movement was within physiological boundaries.

Implantation procedure

Anamnestic data showed no medical history of systemic or metabolic diseases, and the patient did not receive any kind of drug therapy at the time. After a detailed clinical and radiographic examination, the patient was scheduled for implant surgery, one year following the fibular graft transplantation.

The course of surgery: The procedure was performed in local anesthesia. After the elevation of the mucoperiosteal flap, which proved to be difficult due to the abundance of scar tissue, the bone sockets in the fibular graft site were prepared, and three Nobel Replace 4,3x10mm implants were placed in the region of teeth 43, 45 and 46. At that time, the bone density was assessed as D1, with very low blood supply. Healing abutments were placed on the implants, and the wound was sutured around them (Figure 1a). The wound healed partially per secundam intentionem.

Figure 1

Panoramic x-ray immediately after implantation surgery (a), two weeks after implantation surgery, with early signs of crestal radiolucency around two distal implants (b), two months post-implantation follow-up, with clear signs of bone necrosis progressing around two distal implants (c)

Post-implantation clinical findings

Two weeks after the implantation, delayed healing, mild gingival inflammation and bleeding on probing was observed around two distal implants, without any major subjective symptoms reported by the patient. No mobility of the implants was noted.

Due to anatomical limitations in post-reconstructive surgery (high floor of the mouth), retroalveolar radiographs could not be obtained, hence the panoramic radiographs were used to assess peri-implant bone resorption, as has been described by Gbara et al. in 2007 ().

Marginal bone radiolucency in the two distal implants region was observed on the panoramic x-ray, suggesting bone necrosis due to surgical trauma (Figure 1b).

Course of treatment and outcome

Nonsurgical treatment was implemented: rinsing with saline and local drug application (Volon A Haftsalbe ung). Despite the treatments, the resorption of bone seemed to be more pronounced on the panoramic x-ray at two-month post-implantation follow-up; therefore, the decision was made to treat those peri-implant changes with regenerative surgical technique (Figure 1c).

Upon application of a local anesthetic solution (Ubistesin forte 1: 100000) in implanted regions (infiltration anesthesia), the mucoperiosteal flap was elevated and a crater‐shaped bone resorption was observed around the two distal implants, as well as the granulation tissue filling the defects (Figure 2a). The Bio-lase Water-lase Express laser was used to remove granulations. A granulation removal mode was applied, according to the manufacturer's instructions. The mode was then changed and the implant surface was disinfected (Figure 2b). The cleaned surfaces were washed with saline, and a bone substitute Bio-oss, along with collagen membrane Bio-gide were applied, in a guided bone regeneration attempt (Figure 3a and 3b). The surgical site was closed with single interrupted sutures. Systemic antibiotic therapy was prescribed (caps. Amoxicillin, 500mg/8h). A panoramic x-ray was made immediately after surgery to assess the results (Figure 4), as well as at four months follow-up (Figure 5a and 5b). The radiolucencies resolved entirely. Four months after surgery, the implants were loaded with a lateral metal-ceramic bridge (Figure 6).

Figure 2

Clinical situation after raising the mucoperiosteal flap - the granulation tissue filling the defects (a), and a crater‐shaped bone resorption around the two distal implants (b)

Figure 3

The application of bone substitute Bio-oss (a), along with collagen membrane Bio-gide (b)

Figure 4

Panoramic x-ray immediately after GBR surgery to assess the results (Figure 6),

Figure 5

Panoramic x-ray (a) and intraoral status (b) at four months follow-up – the radiolucencies resolved entirely.

Figure 6

The implants loaded with a lateral metal-ceramic bridge – intraoral view

Discussion

As for etiologies suggested in regard to early implant failure, surgical trauma has been stated among the most common factors. Implant failures due to this factor show early radiographical signs of a crater-shaped crestal bone defect, and are surrounded by granulation and fibrous connective tissue ().

Thermally-induced bone necrosis and overcompression are the most probable causes of early implant failure, due to the necrosis of the surrounding differentiated and undifferentiated cells, leading to the failure of bone integration (, ).

Compression of bone beyond its physiologic tolerance and excessive torque placed on an implant may result in high levels of strain transmitted to the adjacent bone and ischemia with subsequent necrosis, especially in the crestal region of an implant, which is often composed of dense cortical bone with a minimal blood supply ().

Although early crestal bone loss may produce the environment that is favorable for anaerobic bacterial growth, especially in one phase implant placement technique as in this case, and thus possibly contribute to more bone destruction in following years, there has been no evidence in the literature that peri-implantitis induces crestal bone loss during the healing period and the first year after prosthetic loading at a faster rate than in the years to follow (, ).

On the other hand, Sakka& Colthard stated that infection is the most common explanation for complications that might occur during the healing period and may, as in the case presented here, include signs such as early mucosal dehiscence that can impair the bone healing process, which leads to the integration of the implant ().

Pellegrino et al. showed a satisfactory long-term survival rate of implants placed into the fibula graft site, but they pointed out the problems of peri-implant bone resorption over time, that is mainly related to peri-implant gingival mucositis, due to the soft tissue quality. The authors suggest that skin or connective tissue grafts in planed implant sites, 2-3 months before implantation procedure, seem to offer an aid to manage this problem ().

Bashutski et al. reported a case in which first signs of radiolucency around implants were apparent one week after implantation, and can clearly be seen 3 weeks post-op, with an apparent delayed healing of the wound, but without clinical signs of infection and no signs of improvement after administration of systemic antibiotic therapy. Histological verification showed aseptic necrosis, with no bacterial infiltration. Some authors believed that overcompression was the most probable cause of the peri-implant necrosis ().

In our case, there were also no clinical signs of infection, only a delayed per sec healing. Considering the specificity of the case itself, the fact that there was no mobility in the implants, and also that the removal of the implants in this phase would probably lead to major defects in the grafted fibula site and the inability for implant placement without additional grafting, the decision was made to implement a protocol for laser-assisted surgical debridement and implant surface sterilization, followed by a guided bone regeneration procedure.

The decision on surgical technique (resective or regenerative) to treat peri-implantitis-like changes depends on the clinical situation. Even if surgery seems to be the therapy of choice, nonsurgical therapy should always be performed before surgical interventions ().

If a crater‐shaped lesion is present around the infected implant, regenerative techniques are needed. A number of different grafting materials, with or without use of a membrane, or the use of membranes alone, have been proposed over the years, in an attempt to regenerate the lost bone and induce re‐osseointegration on the previously contaminated implant surface ().

In a randomized clinical trial Renvert et al. compared augmented sites, with surface debridement and decontamination alone, and concluded that the successful treatment outcome using a bone substitute was more predictable ().

In 2019, Di Carlo et al. reported a GBR procedure performed in the post graft site, in which the onset of peri-implantitis led to the failure of osseointegration with consequent thinning of the fibula flap ().

Following mechanical decontamination, chlorhexidine, citric acid, tetracycline, hydrochloric acid, chloramines, hydrogen peroxide or sodium chloride were used for the purpose of chemical decontamination, and, no agents have yet been shown to be superior ().

Some authors have suggested that decontamination and detoxification of implant surfaces cannot be achieved using hand curettes in narrow bony defects. Also, the infracrestal application of air-powder abrasives may cause embolization, whereas laser application is not associated with such serious risks (, ).

Laser decontamination of the implant surface as an adjunct to surgical regenerative therapies may lead to better clinical results than conventional treatment alone. Clinical improvements have been reported for both the use of lasers and air‐abrasive devices on treatment outcome in the short term and the long term, but the evidence is still weak (, ).

We have decided to use Bio-lase Water-lase Express laser for granulation removal and implant surface disinfection.

In the study of Serino & Turri, the authors concluded that the amount of initial bone loss around the implants seemed to affect disease resolution, and that disease progressed for the implants which showed the signs of peri‐implantitis following the therapy ().

In the case presented here, the bone levels seemed to be stable 6 months following the GBR procedure, suggesting that surgical treatment of early developed peri-implantitis using GBR methods in free fibula graft sites shows promising and stable results. Further exploration of this specific type of cases, with years of follow-up, is needed in order to set the therapy guidelines for peri-implantitis in free fibula graft sites.