In general, autogenous bone is the most predictable material of choice for augmentation procedure. However, the autogenous bone graft procedure requires an additional surgical wound, and the amount of graft is limited because of the donor site. In this case, autogenous corticocancellous bone cores were harvested adjacent to the implant surgical site and the defect, which was distal to the implant surface, was treated with autogenous bone and deproteinized bovine bone. The implant-supported prosthesis was functioning well up to 6 months without any probing depth or gingival inflammation.
In general, autogenous bone is the most predictable material of choice for augmentation procedure.1 This may be due to osteogenic, osteoinductive, and osteoconductive properties associated with undifferentiated cells or osteoblasts surviving within the graft material that may contribute to the new bone formation.2 However, the autogenous bone graft procedure requires an additional surgical wound, and the amount of graft is limited.3
In this case, the bony defect distal to the implant surface was treated with autogenous bone harvested from the area adjacent to the surgical site and deproteinized bovine bone.
A 47-year-old male patient presented to the Department of Periodontology at the Armed Forces Capital Hospital, Seongnam-si, Korea for evaluation of the lower left molar area. The patient had type II diabetes and his diabetic condition was under control with regular evaluation by his physician. His fasting plasma glucose level was below 140 mg/dL, which is recommended by the American Diabetes Association.4
Clinical and radiographic examination indicated that mandibular first and second molars were missing. Insufficient healing around the extraction socket was noticed (Figure 1). The patient was referred to the Department of Prosthodontics for further evaluation and treatment planning. The patient was given a detailed explanation concerning the present state, alternative treatment plans, and the procedure, and informed consent was obtained from the patient. Treatment with placement of dental implant and bone graft was planned after consultation.
Preoperative antibiotics were prescribed, and the patient rinsed for 2 minutes with a 0.12% chlorhexidine digluconate solution (Hexamedine, Bukwang, Seoul, Korea) immediately before the procedure. Following injection of 2% lidocaine with 1∶100 000 epinephrine local anesthetic, a crestal incision was made with mesial and vertical releasing incisions. A surgical template was used to locate the desired implant position, and two 4.1 × 11.5 mm implants (AVANA, Osstem, Seoul, Korea) were placed with the insertion torque of 40 Ncm (Figure 2). There was a 5.5 mm (mesiodistal) × 6.0 mm (buccolingual) defect distal to the most distant implant.
Corticocancellous bone cores were harvested from the buccal shelf next to the surgical area using a trephine bur (ACE Surgical Supply Company Inc, Brockton, Mass) (Figure 3). The cores were then crushed into smaller particle sizes using a rongeur forceps and bone mill. The autogenous bone was packed against the implant surface, and the basal surface of the extraction socket and the rest of the area was then packed with deproteinized bovine bone (Bio-Oss, Geistlich Pharm AG, Wolhusen, Switzerland) (Figure 4). The wound was closed by means of single sutures (Ethicon, Johnson and Johnson Medical Inc, Arlington, Tex).
The patient was placed on amoxicillin 500 mg, 3 times a day for 5 days, mefenamic acid 500 mg initially, then mefenamic acid 250 mg, 4 times a day for 5 days, and chlorhexidine digluconate 0.12%, 3 times a day for 4 weeks. He was asked not to chew on or to brush the surgical area for the first 4 weeks postoperatively, and oral hygiene reinforcement was performed at each visit. The patient reported no specific symptoms, and he did not show any adverse clinical signs.
The 6-week postoperative photograph showed uneventful healing of soft tissue (Figure 5). The radiograph taken at 6 weeks postoperatively showed that the graft material was well stabilized around the defect area (Figure 6). The impression was taken 14 weeks postoperatively (Figures 7 and 8). The prosthesis was delivered 4 months after surgery and no resorption was noticed radiographically (Figure 9). The prosthesis was functioning well up to 6 months without any probing depth or gingival inflammation (Figure 10).
In this case, autogenous bone was applied against the implant surface,3 and the deproteinized bovine bone was placed over the autogenous bone because the bovine bone has osteoconductive properties.5 Overfilling was done in the defect area to compensate for the possible autogenous bone resorption caused by the remodeling.6
Traditionally, the nonresorbable expanded polytetrafluoroethylene membranes have been used to prevent the penetration of nonosteogenic soft tissue and to help preserve the space for new bone growth.7 The disadvantages for using the membranes are that a second surgery is required to remove this membrane, and there is a risk of membrane exposure during the healing period, leading to compromised bone regeneration.8 In this report, graft material was used alone without membrane to avoid a second surgical intervention and to shorten the treatment time.9 Results reported by Hämmerle et al10 showed that vertical bone growth along the implant surface was 52%, in the graft material group without membrane. In comparison, the width of the regenerated bone 1.5 mm above the bottom of the original defect amounted to 42% of the original defect.10 However, there is a limitation that the results from animal studies may not be generally extrapolated to human relevance.
Preoperative antibiotics were used in this diabetic patient with the hope that they may give maximum reduction of infectious complications and fewer implant failures.11,12 Chlorhexidine was applied before and after implant placement to achieve beneficial results of reducing the implant failure rates for diabetic patients.13
In this report, the fasting plasma glucose level was only monitored because his diabetic condition was under control with his physician. Glycosylated hemoglobin A1c (HbA1c) is a good clinical indicator of diabetic control and compliance over 2 or 3 months preceding the test.14 A figure of less than 7% for HbA1c is considered a good level of glycemic control.15 If it is not possible to achieve the glycemic control, it is recommended to postpone implant surgery until ideal glucose control and protein nutrient are achieved.15
In this case, autogenous corticocancellous bone cores were harvested adjacent to the surgical site, and this approach eliminated the need for a remote second surgical donor site and additional morbidity. Additionally, the 1-stage approach, using grafting material at the time of implant placement added the advantage of avoiding a second surgical intervention and shortening the treatment time. Further evaluation is needed to monitor hard and soft tissue changes on a long-term basis.
This work was supported by the Korea Research Foundation Grant funded by the Korean Government (KRF-2008-357-E00015). The author does not have any financial interest in the companies whose materials are included in the article.