A Novel Approach to Grafting Around Implants

INTRODUCTION
Today’s clinicians who provide implant treatment to their patients are more than likely to experience situations that require the extraction of a tooth with concomitant implant placement. In sites where the size of the implant is equal to, or greater than, the residual root socket, it is a straightforward procedure that will not usually require grafting. However, since the shape of the socket will rarely be the cylindrical shape of a dental implant, in most circumstances there will be a moderate-to-large gap between the implant and the walls of the socket—to a lesser extent in bicuspids and to a greater extent in molars.

Grafting the “Gap”
Much has been written regarding how to manage the gap that results when an implant is placed in an extraction socket. When a dental implant is placed into a fresh extraction socket, the space between the implant periphery and surrounding bone is called the “gap” or “jumping distance”.¹ When looking at this space, there is both a vertical and horizontal component that must be addressed, with the horizontal component being more of an issue than the vertical when it comes to final aesthetic outcome. The vertical component’s effect is more on the initial stability of the implant at the time of placement.

Figure 1. An OsteoGen Strip (Impladent).

The main objective of immediate implant placement is to provide an osseointegrated fixture suitable for an aesthetic and functional restoration. Bone fill in the gap between the implant and the peripheral bone is important. Of great concern is the buccal aspect of an implant, especially in the aesthetic zone. This is due to the usually thin buccal bony plate, since its resorption can result in soft-tissue recession.^2-4 The horizontal gap, if less than 2.0 mm, will likely fill in without any intervention by the practitioner. In fact, it has been shown that it is possible to have complete fill-in with a gap of up to 4.2 mm, but this is not predictable.⁵

There are many materials on the market that are used to successfully fill this gap. Allograft, xenograft, and alloplastic materials all work, so it will come down to the clinical advantages and disadvantages of these materials, along with handling characteristics. Allografts work well and turn over within 3 to 5 months, and xenografts can take over 6 months to be resorbed.⁶ Allografts are available in both particulate and putty forms, with the putty being easier in regard to handling properties, but have a downside because allografts do not provide much in the way of contributing to the primary stability of implants in resistance to lateral motion.

The potential issue with particulates (depending upon the particle size) is that if the material ends up in the osteotomy apical to the implant, it is possible to have the graft material prevent your implant from fully seating.

OsteoGen Strips
OsteoGen Strips (Impladent) are a combination of OsteoGen nonceramic bone graft crystals with bovine achilles tendon collagen. The graft material is homogenously mixed with the collagen to create pliable sheets that simplify the placement and delivery of the graft while virtually eliminating the chance of particulate wash out. OsteoGen Strips (Figure 1) were developed specifically to address clinical issues surrounding extraction/immediate placement of implants. OsteoGen Strips were cleared by the FDA in 2009 and, more recently, OsteoGen Plugs (Impladent) were introduced to address the grafting needs of socket preservation.⁷ In addition to sockets, innovative practitioners started utilizing them in immediate implant cases to fill the gaps between the implant and the socket walls.⁸

The graft inside these Plugs and Strips is OsteoGen, a bioactive, non-ceramic (unsintered) calcium phosphate-based graft with physicochemical properties similar to human bone mineral. The unique low-temperature production process generates osteoconductive and resorbable low-density crystals and crystal clusters with a unique calcium-to-phosphate ratio that is neither a beta-tricalcium phosphate nor a dense nonresorbable ceramic hydroxyapatite.^9-11 OsteoGen is highly hydrophilic and has been used as a particulate graft material since 1984 and has documented clinical success for use with implants in periodontal procedures,^12,13 general osseous re-pair,¹⁴ and sinus lifts, including a decade-long longitudinal study of implant survival and success rates.^15-18 The OsteoGen Strips, Plugs, and Crystals are radiolucent on the day of placement, given their low-density properties. Clinicians can follow the healing process radiographically as the site changes from radiolucent to radiopaque as the material is replaced by native bone over the course of 3 to 6 months.

CASE REPORTS
Case 1
A 58-year-old male patient presented with a failing lower first molar (Figure 2) and a non-remarkable medical history. The decision was made to extract the tooth and place an immediate implant.

The tooth was sectioned and the roots were extracted atraumatically to protect the interseptal bone. Further reflection after debridement revealed a 5.0-mm buccal defect adjacent to where the distal root was located (Figure 3). Careful osteotomy preparation allowed for the placement of a 7 x 10 Hahn Tapered Implant (Glidewell Laboratories). Excellent primary stability was attained with a seating torque value of 60 N/cm and an ISQ of 71 (Figure 4). Due to the size of the defect, the decision to not immediately load was decided upon. The alveolous was bleeding profusely, so the establishment of a new blood supply was desired. OsteoGen Strips were placed in the distal socket (Figure 5), the buccal gaps, and around the collar of the implant (Figure 6). A 4- to 6-month collagen membrane (Newport Biologics) was placed using the technique of placing the healing abutment through the membrane (Figure 7). This technique not only stabilizes the membrane, but allows a one-stage surgery to be carried out. The membrane extended buccally past the edges of the defect and extended lingually into the subperiosteal space. The site was sutured with a 4.0 PTFE suture (Figure 8).

Case 2
A 46-year-old female patient presented with a non-restorable tooth No. 19 (Figure 9) and an unremarkable medical history.

The tooth was extracted while preserving the interseptal bone to help facilitate immediate implant placement. A high-speed surgical handpiece with a 557 LS bur was used to create a purchase point for the implant pilot bur (Figure 10). A 5 x 10 Hahn Tapered Implant was placed (Figure 11) with approximately 30 N/cm of torque and an ISQ of 50. Since adequate primary stability was not achieved due to a combination of bone quality and lack of bone-to-implant contact, the implant was stabilized by the tip and its contact with the remnants of the interseptal bone.

OsteoGen Strips were soaked with blood obtained from the socket (Figure 12) and then positioned on the mesial, distal, and buccal aspects around the implant (Figure 13). In order to not compromise the position of the keratinized mucosa, a collagen plug was cut into a disc (Figure 14) and placed over the OsteoGen material, then sutured in a figure-8 fashion with chromic gut sutures (Figure 15). A final radiograph (Figure 16) was taken before the patient was released; it demonstrated the radiolucent appearance of the graft material.

Case 3
A 38-year-old female patient presented to the office with a failed dental im-plant in the area of tooth No. 13 (Figure 17). Pertinent medical history for the patient included infusions of Remicade (Janssen Biotech) every 8 weeks for the treatment of Crohn’s disease.

Once the implant was removed (Figure 18), thorough and aggressive curettage of the site was carried out. Upon continued removal of granulation tissue, a facial perforation was noted. At this point, a full-thickness flap was carried out to expose the defect and facilitate complete degranulation and ultimate repair.

The defect was fully debrided with the use of serrated currettes and a No. 8 round slow-speed carbide bur. The defect extended medially to such a point that it communicated with the Schneiderian membrane of the sinus (Figure 19).

The new implant osteotomy was directed slightly away from the defect, making sure not to compromise the position with respect to restorative needs (Figures 20 and 21). Once the osteotomy was completed, a 4.3 x 8 Hahn Tapered Implant was placed (Figure 22) with a final seating torque value of 50 N/cm. An Osstell unit was used to verify stability with an ISQ of 65 BL and 67 MD (Figure 23).

Profuse bleeding was established by a perforation of the site with a 557 surgical carbide bur. (Note that the establishment of a blood supply is imperative to facilitate complete turnover of the OsteoGen material.) Next, OsteoGen Strips, rehydrated with sterile saline (Figure 24) were used to graft the gap between the implant and the alveolar crest along with the large facial defect (Figure 25). The site was then covered with a 4- to 6-month collagen membrane (Figure 26). Then the site was closed utilizing a 4.0 PTFE suture (Figure 27), and a final radiograph was taken (Figure 28).

CLOSING COMMENTS
The use of this innovative regenerative material has helped make grafting around an implant easier and more predictable. When used in smaller extraction sites, the OsteoGen Strips can be placed against the buccal and lingual walls of the socket and the implant driven between them. In this use, the strips have the ability to potentially contribute to the initial primary stability along with filling any voids.

In clinical situations where labial defects are encountered, OsteoGen Strips provide an excellent regenerative material that will not only fill the void, but will also not migrate from the site during healing. There are many ways to address defects, whether they are infra-bony or extra-bony. However, in the author’s clinical experience, OsteoGen Strips are an easy and cost-effective way to address these issues with outstanding results.

References

1. Botticelli D, Berglundh T, Buser D, et al. The jumping distance revisited: an experimental study in the dog. Clin Oral Implants Res. 2003;14:35-42.
2. Januário AL, Duarte WR, Barriviera M, et al. Dimension of the facial bone wall in the anterior maxilla: a cone-beam computed tomography study. Clin Oral Implants Res. 2011;22:1168-1171.
3. Katranji A, Misch K, Wang HL. Cortical bone thickness in dentate and edentulous human cadavers. J Periodontol. 2007;78:874-878.
4. Chen ST, Darby IB, Reynolds EC. A prospective clinical study of non-submerged immediate implants: clinical outcomes and esthetic results. Clin Oral Implants Res. 2007;18:552-562.
5. Rosenbach DR. GAP management around immediate implants: a review of the literature and its application in clinical practice. Dentaltown. September 2014:44-49.
6. Galindo-Moreno P, Hernández-Cortés P, Mesa F, et al. Slow resorption of anorganic bovine bone by osteoclasts in maxillary sinus augmentation. Clin Implant Dent Relat Res. 2013;15:858-866.
7. Kosinski T. A simple and cost-effective socket preservation technique. Dent Today. 2016;35:90-95.
8. Schlesinger C. Extraction with immediate placement and immediate temporization: the ultimate in patient satisfaction. Implant Practice US. December 2015/January 2016;8:22-25.
9. Valen M, Ganz SD. A synthetic bioactive resorbable graft for predictable implant reconstruction: part one. J Oral Implantol. 2002;28:167-177.
10. Artzi Z, Nemcovsky CE, Dayan D. Nonceramic hydroxyapatite bone derivative in sinus augmentation procedures: clinical and histomorphometric observations in 10 consecutive cases. Int J Periodontics Restorative Dent. 2003;23:381-389.
11. Ricci JL, Blumenthal NC, Spivak JM, et al. Evaluation of a low temperature calcium phosphate particulate implant material: physical-chemical properties and in vivo bone response. J Oral Maxillofac Surg. 1992;50:969-978.
12. Epstein SR, Valen M. An alternative treatment for the periodontal infrabony defect: a synthetic bioactive resorbable composite graft. Dent Today. 2006;25:92-97.
13. Corsair A. A clinical evaluation of resorbable hydroxylapatite for the repair of human intra-osseous defects. J Oral Implantol. 1990;16:125-128.
14. Wagner JR. Clinical and histological case study using resorbable hydroxylapatite for the repair of osseous defects prior to endosseous implant surgery. J Oral Implantol. 1989;15:186-192.
15. Fugazzotto PA, Vlassis J. Long-term success of sinus augmentation using various surgical approaches and grafting materials. Int J Oral Maxillofac Implants. 1998;13:52-58.
16. Vlassis JM, Hurzeler MB, Quinones CR. Sinus lift augmentation to facilitate placement of nonsubmerged implants: a clinical and histological report. Pract Periodontics Aesthet Dent. 1993;5:15-24.
17. Whittaker JM, James RA, Lozada J, et al. Histological response and clinical evaluation of heterograft and allograft materials in the elevation of the maxillary sinus for the preparation of endosteal dental implant sites. Simultaneous sinus elevation and root form implantation: an eight-month autopsy report. J Oral Implantol. 1989;15:141-144.
18. Manso MC, Wassal T. A 10-year longitudinal study of 160 implants simultaneously installed in severely atrophic posterior maxillas grafted with autogenous bone and a synthetic bioactive resorbable graft. Implant Dentistry. 2010;19:351-356.

Dr. Schlesinger is a 1996 graduate of The Ohio State University College of Dentistry. He completed a General Practice Residency after graduation at the Veterans Administration Medical Center (VAMC) in San Diego, Calif, and went on to become the Chief Resident at the VAMC West Los Angeles in California. During his time in Los Angeles, he completed extensive training in oral surgery, implantology, and advanced restorative treatment. Once he completed his residency, he maintained a thriving restorative and implant practice in San Diego for 14 years. In 2012, he relocated to Albuquerque, NM, to become the director of education and clinical affairs for OCO Biomedical. In 2013, he took over as chief operating officer of OCO Biomedical while keeping his clinical responsibilities. In 2016, he left OCO Biomedical and founded the CD Schlesinger Group, LLC (based in Albuquerque), to help practitioners gain knowledge and experience with implants, and he also became a key opinion leader for the Hahn Implant System. In addition to lecturing internationally, he continues to provide comprehensive implant care to patients in a private practice setting in Albuquerque. Dr. Schlesinger is a Fellow of the International Congress of Oral Implantologists. He can be reached at the email address chuck@ocobiomedical.com.

Disclosure: Dr. Schlesinger is a key opinion leader and a lecturer for the Hahn Implant System, for which he receives compensation.

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