Guided Bone Regeneration for Peri-implantitis in the Esthetic Zone: A Case Report
Peri-implantitis is generally described as bone loss around implants with bleeding on probings and possible suppuration. When peri-implantitis involves the esthetic zone the route of intervention should not only resolve the disease but also respect patient’s esthetics. To date, little evidence is available in literature to indicate the most predictable method of treatment for restoration of heathy tissues around implants. The studies that have been conducted to date have a high heterogeneity, particularly regarding defect morphology, surgical protocols, and selection of biomaterials. This report describes a regenerative treatment of 11.2 mm buccal bony defect around a peri-implantits affected implant in the esthetic zone.
The aim of this case report is to present a successful regenerative surgical approach of an advanced peri-implatitis case that occurred in an area of high esthetic demand, namely in the maxillary incisor region.
A 55-year-old female with no history of systemic disease or smoking patient presented with advanced peri-implantitis around left central incisor. The implant #9, placed 8 years prior (2009), was identified as a Straumann4.8 by 12mm Soft Tissue Level, regular neck (RN), SLA Active with a cement retained crown on a RN solid abutment and a machined collar of 1.8 mm in height. An examination revealed PDs from 5 to 8mm, bleeding and suppuration on probing. CBCT scan showed a 11.2 mm buccal defect and the presence of a tooth fragment. A regenerative procedure was preferred over the explantation. Firstly, considering the size of the implant (4.8 by 12mm), explantation would have posed a more challenging rehabilitation process with a difficult restoration of the bone ridge anatomy and soft tissues. In addition, the contained anatomy of the bony defect and the thick gingival biotype of the patient would facilitate the outcome of a possible graft. The patient’s esthetic demand and preference to opt for a less invasive and time consuming treatment played also a role. The patient was informed about the possible collapse of the mesial papilla of the adjacent lateral maxillary incisor (#10) after the regenerative treatment due to flap incision and a possible need for a new crown for #10, with a lower marginal preparation to overcome the exposed margin.
Vertical incisions were made distal to #7and #11 in order to include the exostosis, which were the source of autogenous bone graft. Intrasulcular incisions were made on both buccal and palatal side from #7 to #11. A full thickness flap was raised buccally and to a minor extent palatally. Thorough debridement of the implant surface was performed with titanium handscalers and a rotary titanium brush comprising titanium alloy bristles (Straumann, TiBrush). Bony defect was observed on buccal (five to six threads exposed) and palatal (two thread exposed) along with a tooth fragment on the distofacial aspect of the implant. The implant surface was decontaminated with abundant irrigations with saline solution and chlorhexidine gluconate 0,12% and 0.6 ml of 24% ethylenediaminetetraacetic acid (EDTA) surface gel conditioner (Straumann, Emdogain PrefGel) was applied for 120 seconds on the implant surface. Autogenous bone was obtained from the exostosis with a bone scraper, mixed with gentamicin sulfate 80mg/2ml and used to fill the defect. The existing graft was bulked with 0.5g bovine derived xenograft (Geistlich,Bio-Oss small granules 0,25-1mm) mixed with enamel matrix derivative (Straumann, Emdogain) to enhance the viscosity and stabilization of the graft. A resorbable bilayer collagen membrane (Geistlich,Bio-Gide, 13x25mm) was trimmed following the ridge anatomy, applied and then stabilized with two tacks (ACESurgical Supply Co., TRUtacks) on the buccal plate. Primary closure was achieved. A new essix retainer was delivered for esthetics, avoiding pressure on the surgical wound. The patient was dismissed and did not report significant post-operative discomfort.
RESULTS & CONCLUSION
At 9 months, a new CBCT scan was performed for planning of the implant #14 and the field of view was extended to #9 in order to re-evaluate the results from the regenerative treatment.The comparison between pre and post operative Cone Beam CT showed a vertical bone level gain of 11.2 mm buccally and 2.3 mm palatally, and a 2.5 mm thick buccal plate. Calibrated measurements comparing pre and post-operative CBCT scans were performed with ImageJ software (National Institute of Health, NIH), knowing the 1.25 mm thread pitch of the 4.8mm wide Straumann implant. The final restoration for #9 and crown on #10 were delivered in the Division of Advanced Education in General Dentistry (AEGD), UConn at 9 months. At 14 months follow up, probing depths were within normal limits, ranging from 2 to 3 mm and no alteration of marginal soft tissues was noted. The implant was restored with a custom abutment.
With the regenerative technique used in this case report, explantation was avoided, peri-implant tissues were brought back to health, and esthetics were preserved.