The International Journal of Periodontics & Restorative Dentistry © 2014 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
s51
Socket Preservation Procedure with Equine Bone Mineral: A Case Series Myron Nevins, DDS1/Emil G. Cappetta, DMD2 Dan Cullum, DDS3/Wahn Khang, DMD4/Craig Misch, DDS, MDS5 Paul Ricchetti6/Anthony Sclar, DMD7/Stephen S. Wallace, DDS8 Daniel Kuan-Te Ho, DMD, DMSc, MSc9/David M. Kim, DDS, DMSc10
Conventional dentoalveolar osseous augmentation procedures for creating bone volume for dental implant placement often involve the use of grafting materials with or without barrier membranes to foster selective cell and tissue repopulation. A study was conducted to determine the efficacy of equine particulate bone (Equimatrix, Osteohealth) to augment the creation of new bone and preserve the volume of bone at extraction sites for the purpose of placing an implant in an optimal position for restoration. Clinical and histologic evidence supported the suitability of equine particulate bone for extraction site augmentation that allowed dental implant placement after a 6-month healing period. (Int J Periodontics Restorative Dent 2014;34(suppl):s51–s57. doi: 10.11607/prd.2139)
Associate Clinical Professor, Division of Periodontology, Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, Massachusetts, USA. 2Private Practice, Summit, New Jersey, USA. 3Private Practice, Coeur d’Alene, Idaho, USA. 4Clinical Assistant Professor, Department of Periodontics, University of Maryland Dental School, Baltimore, Maryland, USA. 5Clinical Associate Professor, Department of Implant Dentistry, New York University College of Dentistry, New York, New York, USA. 6Private Practice, Mayfield Heights, Ohio, USA. 7Private Practice, Miami, Florida, USA. 8Associate Clinical Professor, Department of Periodontics, Columbia University College of Dental Medicine, New York, New York, USA. 9Assistant Professor, Department of Periodontics, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, Texas, USA. 10Associate Professor, Division of Periodontology, Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, Massachusetts, USA. 1
Correspondence to: Dr Myron Nevins, Harvard School of Dental Medicine, 188 Longwood Avenue, Boston, MA 02115; fax: 617-432-19897; email: [email protected]. ©2014 by Quintessence Publishing Co Inc.
The use of dental implants in the partially and fully edentulous patient with deficient bone volume has given rise to a new demand for bone reconstruction before or during implant therapy to achieve optimal esthetics. A prominent root position is frequently accompanied by a thin, frail buccal plate that may be damaged during tooth removal, resulting in a deformed edentulous ridge of which the bone morphology would require augmentation prior to implant placement.1 Hence, preservation of the alveolus at the time of extraction of teeth with prominent roots in the anterior maxilla is crucial to allow optimal implant placement.1 Fortunately, continuous innovations in surgical techniques and advances in the biologic understanding of bone regeneration techniques have led to improved implant procedures and an increased predictability in the reconstruction of alveolar ridge defects.2–4 Conventional dentoalveolar osseous augmentation procedures for creating bone volume for dental implants often involve the use of grafting materials with or
Volume 34, Supplement, 2014 © 2014 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
s52 without barrier membranes to foster selective cell and tissue repopulation.5 However, the clinical and histologic efficacy of the material is dependent on its type, source, and biocompatibility together with the provision of space maintenance.4 It is considered that particulate bone can be advantageous compared to block bone due to smaller pieces allowing more rapid ingrowth of blood vessels, a larger osteoconductive surface, and easier biologic remodeling. The purpose of this proof-of-principle investigation was to determine the efficacy of particulated equine bone mineral (EBM) (Equimatrix, Osteohealth) to augment the creation of new bone and preserve the volume of bone at extraction sites for the purpose of placing an implant in an optimal position for restoration. The primary objective of this proposed prospective case series was to demonstrate the clinical efficacy of EBM in providing hard tissue regeneration in the socket preservation procedure by means of clinical, radiographic, histologic, and histomorphometric analyses.
Method and materials Twelve healthy patients, eight women and four men ranging in age from 27 to 66 years, were recruited from seven centers for this prospective case series study. The informed consent, based on the Helsinki Declaration of 1975 as revised in 2000, was signed by each patient following a personal-
ized review at a separate consultation appointment. The 12 patients were prepared for surgery in accordance with accepted dental practice guidelines after appropriate demographic information and medical history were taken. Following extraction of 17 maxillary teeth (anterior to and including the premolars), socket preservation procedures were performed.
Inclusion Criteria
1. Subjects (male and female) between 20 and 70 years of age who elect the dental implant treatment option for rehabilitation. 2. A willingness to sign an informed consent, participate, and return for follow-up visits. 3. A nonsignificant medical history and no current use of medications that might complicate results. 4. An enclosed extraction site (without a buccal wall defect).
Exclusion Criteria
1. Failure to meet all inclusion criteria or an unwillingness to cooperate with the protocol schedule. 2. A prior failed dental implant. 3. A need for an onlay ridge augmentation procedure in the area to achieve adequate bone volume for the placement of dental implants. 4. The presence of significant untreated periodontal disease,
caries, infection, or chronic inflammation in the oral cavity within two adjacent tooth positions of the clinical trial area. 5. The use of a nicotinecontaining product within 3 weeks prior to surgery. 6. Insulin-dependent diabetes or HgB1c levels > 6.5%. 7. A history of malignancy (except basal or squamous cell carcinoma of the skin or in situ cervical carcinoma) within the past 5 years. 8. Women who are nursing or pregnant. 9. Current use of medications (except estrogen/progesterone therapy) or treatment that is known to have an effect on bone turnover. 10. The presence of any disease that affects bone metabolism (excluding idiopathic osteoporosis). 11. History of an autoimmune disease, documented allergy, or multiple allergies to any component of the agents used in the study. 12. A difficult extraction with potential disruption/fracture of the alveolar bone. 13. An acutely infected defect site.
The Surgical Preservation Procedure
The surgical procedures were performed on an outpatient basis following radiographic and clinical examinations and oral hygiene instructions (Fig 1a). The patients
The International Journal of Periodontics & Restorative Dentistry © 2014 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
s53 were seen at 1, 2, 4, 8, 12, and 24 weeks until biopsy, and dental CT scans were taken following the extraction and after 6 months of healing. After local anesthesia was administered to the area of the planned extraction, full-thickness flaps were elevated with a horizontal and a vertical incision as needed to reveal the bone surface (Fig 1b). The extraction site was debrided and evaluated, and cortical perforations were made if necessary for bleeding before the EBM was delivered into the socket (Fig 1c). The flaps were coapted for primary closure with no barrier membranes. A 6-month core biopsy was planned for retrieval with a cylindrical trephine bone bur equipped with a 2-mm core.
Postsurgical Care
Patients were instructed not to brush or floss at the surgical site(s) until the sutures were removed 10 to 21 days postoperatively, when the flap had become stabilized. Patients were instructed to rinse with chlorhexidine mouthrinse (0.12%) daily until the sutures were removed.
Light microscopy and histomorphometric analysis
Once completely dehydrated, the bone cores were embedded in ascending grades of ethanol (60%, 80%, 96%, and absolute) in a light-curing, single-component
composite resin (Technovit 7200 VLC, Heraeus Kulzer). Polymerized blocks were initially ground to bring the tissue components closer to the cutting surface. A 100-µm-thick section attached to the second slide was sawed with a diamond blade under 50 to 100 g of pressure. The final thickness of 40 µm was achieved by grinding and final polishing with 1,200-, 2,400-, and 4,000-grit sandpaper. Sections from each block were stained with Sanderson’s Rapid Bone Stain (SRBS) and acid fuchsin counterstain. Light microscopy overview images of the cores were taken digitally with a Leica M16 stereomicroscope (Leica Microsystems). Histomorphometric measurements were performed using software (ImageAccess) to calculate the percentages of mineralized bone, soft tissue components (connective tissue and/or bone marrow), and residual graft particles.
Results In this case series, 17 maxillary extraction site regeneration surgeries were performed. Healing was uneventful, with minimal soft tissue inflammation and no signs of infection. At 6 months, sufficient regenerated bone was present at each site for successful implant placement (Figs 1d to 1i). A histologic study of core biopsy specimens demonstrates the range of bone regeneration observed at 6 months. Figure 2a represents an intact core obtained at
the time of implant placement, 6 months after the extraction site grafting, showing significant quantities of both lamellar and newly regenerated woven bone. The regenerated bone is surrounded by and interconnected with intact EBM particles, and active bridging of newly formed bone can be seen throughout the apical portion of the core specimen (Fig 2b). No evidence of an inflammatory infiltrate is present in this core specimen. Vital osteocytes and evidence of remodeling bone can be observed throughout the core (Fig 2c). At higher magnification, osteocytes— indicative of healthy, vital bone— are readily apparent throughout the newly regenerated bony area. As in the first core, active bridging of newly regenerated bone is readily apparent in the second core (Fig 3a). At higher magnification, newly formed bone can be seen in intimate contact with residual EBM particles, verifying the osteoconductivity of EBM (Fig 3b). Lacunae with vital osteocytes are seen throughout areas of regenerated bone.
Histomorphometric Results
At 6 months following the bone preservation procedure, histomorphometric quantitative results supported the qualitative histologic findings. The mean histometric results of analyzed cores are as follows: mean percent bone, 28.8%; mean percent residual graft particles, 25.7%; mean percent marrow/ connective tissue, 45.6%.
Volume 34, Supplement, 2014 © 2014 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
s54
Fig 1a A patient presented with compromised teeth (maxillary right second and first molar and second premolar) and elected to replace them with dental implants.
Fig 1b Atraumatic extraction was performed to preserve the buccal plate.
Fig 1c Extraction sockets were grafted with EBM.
Fig 1d A postoperative radiograph demonstrated preservation of ridge height.
Fig 1e Clinical re-entry of the grafted sites, demonstrating sufficiently dense bone to receive dental implants.
Fig 1f Postoperative radiograph taken after the implant placement.
Fig 1g (left) Radiographic view of periodontally compromised dentition. The decision was made to extract the maxillary right second premolar. Fig 1h (right) Dental CT scan demonstrating preserved ridge dimension after the grafting procedure.
Fig 1i Radiographic view of a dental implant successfully placed into the grafted site.
The International Journal of Periodontics & Restorative Dentistry © 2014 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
s55 Fig 2a Histologic view of an intact core demonstrating significant quantities of dense, some lamellar, and newly regenerated woven bone in the apical portion of the specimen.
New bone
NB
G
Graft
New bone
G
NB
G Bone remodeling cone
NB G
G
G G
200 μm
Fig 2b Specimen showing active bridging of newly formed bone throughout (NB = new bone; G = graft particles). Fig 3a As in the first core, active bridging of newly regenerated bone is readily apparent in this core.
New bone
100 μm
Fig 2c Specimen showing evidence of remodeling cone throughout the core (G = graft particles). Graft
New bone
Graft
New bone Fig 3b Higher magnification view shows newly formed bone (NB) in intimate contact with residual EBM particles (G), verifying the osteoconductivity of EBM.
CT G
G NB
NB G G
NB G
G
G 200 μm
Volume 34, Supplement, 2014 © 2014 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
s56 Discussion Significant knowledge exists of the healing process of extraction wounds, including contour changes caused by bone resorption and the cascade of histologic events in both animals and humans.6–10 Resorption of the alveolar process following tooth extraction in both jaws is significantly greater on the buccal aspect than on the lingual or palatal, resulting in a greater reduction in the width of the maxillary alveolar ridge than in the height.11–13 The most significant loss of tissue contour takes place during the first month after tooth extraction and averages 3 to 5 mm after 6 months.14–18 Bovine-derived bone mineral xenografts have consistently demonstrated successful long-term implant survival when used alone or in combination with other matrices.19–23 Evidence further documents a range of values for an effective percentage of new vital bone formation at various time points when bovine xenografts are used.24–29 The earliest documented time point following extraction grafting is generally 6 months, and average regenerated bone values range from approximately 12.5% to 24%.24,25,30–33 This proof-of-principle case series of an equine-derived bone mineral matrix, with physical and chemical characteristics similar to those of other xenografts, was used for extraction site augmentation procedures to prepare for implant placement. Study outcomes included histomorphometric and histo-
logic findings at 6 months following grafting, which demonstrated newly regenerated bone surrounded by and in intimate contact with residual EBM particles. Active bridging between EBM particles with newly formed bone was routinely observed in the core biopsy specimens, and no evidence of an inflammatory cell infiltrate was found. Histomorphometric values of percentage vital bone proved comparable to reported mean values of bovine-derived bone mineral xenografts. With vital bone formation values ranging from 17.9% to 39.1%, and a mean value of 28.8%, EBM in this initial case series appears comparable to other bone mineral xenografts in terms of its osteoconductive ability to support new bone formation at 6 months in socket preservation procedures.27 Although the results of this study are promising, longer-term studies are needed to determine bone regeneration trends at later time points. In addition, clinical studies examining long-term implant survival under function are needed to gain a comprehensive understanding of the potential role of EBM for osteogenic procedures.
Conclusions Clinical and histologic evidence supported the suitability of EBM for extraction site augmentation, which resulted in subsequent dental implant placement after a 6-month healing period. There were no adverse events encountered with these procedures.
Acknowledgments This study was sponsored by a grant from Osteohealth. The authors reported no conflicts of interest related to this study.
References 1. Nevins M, Camelo M, Sergio DP, et al. A study of the fate of the buccal wall of extraction sockets of teeth with prominent roots. Int J Periodontics Restorative Dent 2006;26:19–29. 2. Klokkevold PR, Newman MG. Current status of dental implants: A periodontal perspective. Int J Oral Maxillofacial Implants 2000;15:56–65. 3. Mellonig JT, Nevins M. Guided bone regeneration of bone defects associated with implants: An evidence-based outcome assessment. Int J Periodontics Restorative Dent 1995;15:168–185. 4. Nevins M, Mellonig JT, Clem DS 3rd, Reiser GM, Buser DA. Implants in regenerated bone: Long-term survival. Int J Periodontics Restorative Dent 1998; 18:34–45. 5. Fiorellini JP, Howell TH, Cochran D, et al. Randomized study evaluating recombinant human bone morphogenetic protein-2 for extraction socket augmentation. J Periodontol 2005;76:605–613. 6. Carlsson H, Thilander H, Hedegard B. Histologic changes in the upper alveolar process after extractions with or without insertion of an immediate full denture. Acta Odontol Scand 1967;25:21–43. 7. Huebsch RF, Hansen LS. A histopathologic study of extraction wounds in dogs. Oral Surg Oral Med Oral Pathol 1969; 28:187–196. 8. Amler MH, Johnson PL, Salsman I. Histologic and histochemical investigation of human alveolar sockets healing in undisturbed extraction wounds. J Am Dent Assoc 1960;61:46–48. 9 Iasella JM, Greenwell H, Miller RL, et al. Ridge preservation with freeze-dried bone allograft and a collagen membrane compared to extraction alone for implant site development. J Periodontol 2003; 74:990–999. 10. Pietrokovski J, Massler M. Alveolar ridge resorption following tooth extraction. J Prosthet Dent 1967;17:21–27. 11. Cardaropoli G, Aravjo M, Lindhe J. Dynamics of bone tissue formation in tooth extraction sites. An experimental study in dogs. J Clin Periodontol 2003;30: 809–818.
The International Journal of Periodontics & Restorative Dentistry © 2014 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
s57
12. Johnson K. A study of the dimensional changes occurring in the maxilla following closed face immediate denture treatment. Aust Dent J 1969;14:370–376. 13. Araujo MG, Lindhe J. Dimensional ridge alterations following tooth extraction. An experimental study in the dog. J Clin Periodontol 2005;32:212–218. 14. Lam RV. Contour changes of the alveolar process following extraction. J Prosthet Dent 1960;10:25–32L 15. Schropp L, Wenzel A, Kostopoulos L, Karring T. Bone healing and soft tissue contour changes following single-tooth extraction: A clinical and radiographic 12-month prospective study. Int J Periodontics Restorative Dent 2003;23: 313–323. 16. Lekovic V, Kennev EB, Weinlaender M, et al. A bone regenerative approach to alveolar ridge maintenance following tooth extraction. Report of 10 cases. J Periodontol 1997;68:363–370. 17. Lekovic V, Camargo PM, Klokkevold PR, et al. Preservation of alveolar bone in extraction sockets using bioabsorbable membranes. J Periodontol 1998;69: 1044–1049. 18. Camargo PM, Lekovic V, Weinlaender M, et al. Influence of bioactive glass on changes in alveolar process dimensions after exodontias. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2000;90: 581–586. 19. Wallace SS, Froum SJ. Effect of maxillary sinus augmentation on the survival of endosseous dental implants. A systematic review. Ann Periodontol 2003;8:328–343. 20. Del Fabbro M, Testori T, Francetti I, et al. Systematic review of survival rates for implants placed in the grafted maxillary sinus. Int J Periodontics Restorative Dent 2004;24:565–577.
21. Del Fabbro M, Rosano G, Taschieri S. Implant survival rates after maxillary sinus augmentation. Eur J Oral Sci 2008; 116:497–506. 22. Del Fabbro M, Bortolin M, Taschieri S, et al. Implant survival after maxillary sinus augmentation. An updated systematic review. J Osteo Biomat 2010;1:69–79. Erratum in: J Osteol Biomat 2010;1:186. 23. Pjetursson BE, Tan WC, Zwahlen M, Lang NP. A systematic review of the success of sinus floor elevation and survival of implants inserted in combination with sinus floor elevation. Part I: Lateral approach. J Clin Periodontol 2008;35 (Suppl 8): 216–224. 24. Froum SJ, Wallace SS, Cho SC, Elian N, Tarnow DP. Comparison of mineralized cancellous allograft (Puros) and anorganic bovine bone matrix (Bio-Oss) for sinus augmentation: Histomorphometry at 26 to 32 weeks after grafting. Int J Periodontics Restorative Dent 2006;26:543–551. 25. Lee YM, Shin Sy, Kim JY, Kye SB, Ku Y, Rhyu IC. Bone reaction to bovine hydroxyapatite for maxillary sinus floor augmentation: Histologic results in humans. Int J Periodontics Restorative Dent 2006;26:471–481. 26. Froum SJ, Wallace SS, Cho SC, Elian N, Tarnow DP. Histomorphometric comparison of a biphasic bone ceramic to anorganic bovine bone for sinus augmentation: 6- to 8-month postsurgical assessment of vital bone formation. A pilot study. Int J Periodontics Restorative Dent 2008;28:273–281. 27. Nevins M, Camelo M, De Angelis N, et al. The clinical and histologic efficacy of xenograft granules for maxillary sinus floor augmentation. Int J Periodontics Restorative Dent 2011;31:227–235.
28. Zerbo IR, Zijdervels SA, de Boer A, et al. Histomorphometry of human sinus floor augmentation using a porous beta-tricalcium phosphate: A prospective study. Clin Oral Implants Res 2004;15:724–732. 29. Fugazzotto PA. GBR using bovine bone matrix and resorbable and nonresorbable membranes. Part 1: Histologic results. Int J Periodontics Restorative Dent 2003;23:361–369. 30. Wallace SS, Cho S-C, Monteiro D, Tarnow DP. Sinus augmentation utilizing anorganic bovine bone (Bio-Oss) with absorbable and nonabsorbable membranes placed over the lateral window: Histomorphometric and clinical analyses. Int J Periodontics Restorative Dent 2005; 25:551–559. 31. Froum SJ, Tarnow DP, Wallace SS, Roher MD, Cho S-C. Sinus floor elevation using anorganic bovine bone matrix (OteoGraf/N) with and without autogenous bone: A clinical, histologic, radiographic, and histomorphometric analysis – Part 2 of an ongoing prospective study. Int J Periodontics Restorative Dent 1998; 18:529–543. 32. Ferreira CEA, Novaes Jr AB, Haraszthy VI, et al. A clinical study of 406 sinus augmentations with 100% anorganic bovine bone. J Periodontol 2009;80:1920–1927. 33. Valentini P, Abensur D, Wenz B, et al. Sinus grafting with porous bone mineral (Bio-Oss) for implant placement: A 5-year study on 15 patients. Int J Periodontics Restorative Dent 2000;20:245–253.
Volume 34, Supplement, 2014 © 2014 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
s51
Socket Preservation Procedure with Equine Bone Mineral: A Case Series Myron Nevins, DDS1/Emil G. Cappetta, DMD2 Dan Cullum, DDS3/Wahn Khang, DMD4/Craig Misch, DDS, MDS5 Paul Ricchetti6/Anthony Sclar, DMD7/Stephen S. Wallace, DDS8 Daniel Kuan-Te Ho, DMD, DMSc, MSc9/David M. Kim, DDS, DMSc10
Conventional dentoalveolar osseous augmentation procedures for creating bone volume for dental implant placement often involve the use of grafting materials with or without barrier membranes to foster selective cell and tissue repopulation. A study was conducted to determine the efficacy of equine particulate bone (Equimatrix, Osteohealth) to augment the creation of new bone and preserve the volume of bone at extraction sites for the purpose of placing an implant in an optimal position for restoration. Clinical and histologic evidence supported the suitability of equine particulate bone for extraction site augmentation that allowed dental implant placement after a 6-month healing period. (Int J Periodontics Restorative Dent 2014;34(suppl):s51–s57. doi: 10.11607/prd.2139)
Associate Clinical Professor, Division of Periodontology, Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, Massachusetts, USA. 2Private Practice, Summit, New Jersey, USA. 3Private Practice, Coeur d’Alene, Idaho, USA. 4Clinical Assistant Professor, Department of Periodontics, University of Maryland Dental School, Baltimore, Maryland, USA. 5Clinical Associate Professor, Department of Implant Dentistry, New York University College of Dentistry, New York, New York, USA. 6Private Practice, Mayfield Heights, Ohio, USA. 7Private Practice, Miami, Florida, USA. 8Associate Clinical Professor, Department of Periodontics, Columbia University College of Dental Medicine, New York, New York, USA. 9Assistant Professor, Department of Periodontics, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, Texas, USA. 10Associate Professor, Division of Periodontology, Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, Massachusetts, USA. 1
Correspondence to: Dr Myron Nevins, Harvard School of Dental Medicine, 188 Longwood Avenue, Boston, MA 02115; fax: 617-432-19897; email: [email protected]. ©2014 by Quintessence Publishing Co Inc.
The use of dental implants in the partially and fully edentulous patient with deficient bone volume has given rise to a new demand for bone reconstruction before or during implant therapy to achieve optimal esthetics. A prominent root position is frequently accompanied by a thin, frail buccal plate that may be damaged during tooth removal, resulting in a deformed edentulous ridge of which the bone morphology would require augmentation prior to implant placement.1 Hence, preservation of the alveolus at the time of extraction of teeth with prominent roots in the anterior maxilla is crucial to allow optimal implant placement.1 Fortunately, continuous innovations in surgical techniques and advances in the biologic understanding of bone regeneration techniques have led to improved implant procedures and an increased predictability in the reconstruction of alveolar ridge defects.2–4 Conventional dentoalveolar osseous augmentation procedures for creating bone volume for dental implants often involve the use of grafting materials with or
Volume 34, Supplement, 2014 © 2014 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
s52 without barrier membranes to foster selective cell and tissue repopulation.5 However, the clinical and histologic efficacy of the material is dependent on its type, source, and biocompatibility together with the provision of space maintenance.4 It is considered that particulate bone can be advantageous compared to block bone due to smaller pieces allowing more rapid ingrowth of blood vessels, a larger osteoconductive surface, and easier biologic remodeling. The purpose of this proof-of-principle investigation was to determine the efficacy of particulated equine bone mineral (EBM) (Equimatrix, Osteohealth) to augment the creation of new bone and preserve the volume of bone at extraction sites for the purpose of placing an implant in an optimal position for restoration. The primary objective of this proposed prospective case series was to demonstrate the clinical efficacy of EBM in providing hard tissue regeneration in the socket preservation procedure by means of clinical, radiographic, histologic, and histomorphometric analyses.
Method and materials Twelve healthy patients, eight women and four men ranging in age from 27 to 66 years, were recruited from seven centers for this prospective case series study. The informed consent, based on the Helsinki Declaration of 1975 as revised in 2000, was signed by each patient following a personal-
ized review at a separate consultation appointment. The 12 patients were prepared for surgery in accordance with accepted dental practice guidelines after appropriate demographic information and medical history were taken. Following extraction of 17 maxillary teeth (anterior to and including the premolars), socket preservation procedures were performed.
Inclusion Criteria
1. Subjects (male and female) between 20 and 70 years of age who elect the dental implant treatment option for rehabilitation. 2. A willingness to sign an informed consent, participate, and return for follow-up visits. 3. A nonsignificant medical history and no current use of medications that might complicate results. 4. An enclosed extraction site (without a buccal wall defect).
Exclusion Criteria
1. Failure to meet all inclusion criteria or an unwillingness to cooperate with the protocol schedule. 2. A prior failed dental implant. 3. A need for an onlay ridge augmentation procedure in the area to achieve adequate bone volume for the placement of dental implants. 4. The presence of significant untreated periodontal disease,
caries, infection, or chronic inflammation in the oral cavity within two adjacent tooth positions of the clinical trial area. 5. The use of a nicotinecontaining product within 3 weeks prior to surgery. 6. Insulin-dependent diabetes or HgB1c levels > 6.5%. 7. A history of malignancy (except basal or squamous cell carcinoma of the skin or in situ cervical carcinoma) within the past 5 years. 8. Women who are nursing or pregnant. 9. Current use of medications (except estrogen/progesterone therapy) or treatment that is known to have an effect on bone turnover. 10. The presence of any disease that affects bone metabolism (excluding idiopathic osteoporosis). 11. History of an autoimmune disease, documented allergy, or multiple allergies to any component of the agents used in the study. 12. A difficult extraction with potential disruption/fracture of the alveolar bone. 13. An acutely infected defect site.
The Surgical Preservation Procedure
The surgical procedures were performed on an outpatient basis following radiographic and clinical examinations and oral hygiene instructions (Fig 1a). The patients
The International Journal of Periodontics & Restorative Dentistry © 2014 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
s53 were seen at 1, 2, 4, 8, 12, and 24 weeks until biopsy, and dental CT scans were taken following the extraction and after 6 months of healing. After local anesthesia was administered to the area of the planned extraction, full-thickness flaps were elevated with a horizontal and a vertical incision as needed to reveal the bone surface (Fig 1b). The extraction site was debrided and evaluated, and cortical perforations were made if necessary for bleeding before the EBM was delivered into the socket (Fig 1c). The flaps were coapted for primary closure with no barrier membranes. A 6-month core biopsy was planned for retrieval with a cylindrical trephine bone bur equipped with a 2-mm core.
Postsurgical Care
Patients were instructed not to brush or floss at the surgical site(s) until the sutures were removed 10 to 21 days postoperatively, when the flap had become stabilized. Patients were instructed to rinse with chlorhexidine mouthrinse (0.12%) daily until the sutures were removed.
Light microscopy and histomorphometric analysis
Once completely dehydrated, the bone cores were embedded in ascending grades of ethanol (60%, 80%, 96%, and absolute) in a light-curing, single-component
composite resin (Technovit 7200 VLC, Heraeus Kulzer). Polymerized blocks were initially ground to bring the tissue components closer to the cutting surface. A 100-µm-thick section attached to the second slide was sawed with a diamond blade under 50 to 100 g of pressure. The final thickness of 40 µm was achieved by grinding and final polishing with 1,200-, 2,400-, and 4,000-grit sandpaper. Sections from each block were stained with Sanderson’s Rapid Bone Stain (SRBS) and acid fuchsin counterstain. Light microscopy overview images of the cores were taken digitally with a Leica M16 stereomicroscope (Leica Microsystems). Histomorphometric measurements were performed using software (ImageAccess) to calculate the percentages of mineralized bone, soft tissue components (connective tissue and/or bone marrow), and residual graft particles.
Results In this case series, 17 maxillary extraction site regeneration surgeries were performed. Healing was uneventful, with minimal soft tissue inflammation and no signs of infection. At 6 months, sufficient regenerated bone was present at each site for successful implant placement (Figs 1d to 1i). A histologic study of core biopsy specimens demonstrates the range of bone regeneration observed at 6 months. Figure 2a represents an intact core obtained at
the time of implant placement, 6 months after the extraction site grafting, showing significant quantities of both lamellar and newly regenerated woven bone. The regenerated bone is surrounded by and interconnected with intact EBM particles, and active bridging of newly formed bone can be seen throughout the apical portion of the core specimen (Fig 2b). No evidence of an inflammatory infiltrate is present in this core specimen. Vital osteocytes and evidence of remodeling bone can be observed throughout the core (Fig 2c). At higher magnification, osteocytes— indicative of healthy, vital bone— are readily apparent throughout the newly regenerated bony area. As in the first core, active bridging of newly regenerated bone is readily apparent in the second core (Fig 3a). At higher magnification, newly formed bone can be seen in intimate contact with residual EBM particles, verifying the osteoconductivity of EBM (Fig 3b). Lacunae with vital osteocytes are seen throughout areas of regenerated bone.
Histomorphometric Results
At 6 months following the bone preservation procedure, histomorphometric quantitative results supported the qualitative histologic findings. The mean histometric results of analyzed cores are as follows: mean percent bone, 28.8%; mean percent residual graft particles, 25.7%; mean percent marrow/ connective tissue, 45.6%.
Volume 34, Supplement, 2014 © 2014 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
s54
Fig 1a A patient presented with compromised teeth (maxillary right second and first molar and second premolar) and elected to replace them with dental implants.
Fig 1b Atraumatic extraction was performed to preserve the buccal plate.
Fig 1c Extraction sockets were grafted with EBM.
Fig 1d A postoperative radiograph demonstrated preservation of ridge height.
Fig 1e Clinical re-entry of the grafted sites, demonstrating sufficiently dense bone to receive dental implants.
Fig 1f Postoperative radiograph taken after the implant placement.
Fig 1g (left) Radiographic view of periodontally compromised dentition. The decision was made to extract the maxillary right second premolar. Fig 1h (right) Dental CT scan demonstrating preserved ridge dimension after the grafting procedure.
Fig 1i Radiographic view of a dental implant successfully placed into the grafted site.
The International Journal of Periodontics & Restorative Dentistry © 2014 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
s55 Fig 2a Histologic view of an intact core demonstrating significant quantities of dense, some lamellar, and newly regenerated woven bone in the apical portion of the specimen.
New bone
NB
G
Graft
New bone
G
NB
G Bone remodeling cone
NB G
G
G G
200 μm
Fig 2b Specimen showing active bridging of newly formed bone throughout (NB = new bone; G = graft particles). Fig 3a As in the first core, active bridging of newly regenerated bone is readily apparent in this core.
New bone
100 μm
Fig 2c Specimen showing evidence of remodeling cone throughout the core (G = graft particles). Graft
New bone
Graft
New bone Fig 3b Higher magnification view shows newly formed bone (NB) in intimate contact with residual EBM particles (G), verifying the osteoconductivity of EBM.
CT G
G NB
NB G G
NB G
G
G 200 μm
Volume 34, Supplement, 2014 © 2014 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
s56 Discussion Significant knowledge exists of the healing process of extraction wounds, including contour changes caused by bone resorption and the cascade of histologic events in both animals and humans.6–10 Resorption of the alveolar process following tooth extraction in both jaws is significantly greater on the buccal aspect than on the lingual or palatal, resulting in a greater reduction in the width of the maxillary alveolar ridge than in the height.11–13 The most significant loss of tissue contour takes place during the first month after tooth extraction and averages 3 to 5 mm after 6 months.14–18 Bovine-derived bone mineral xenografts have consistently demonstrated successful long-term implant survival when used alone or in combination with other matrices.19–23 Evidence further documents a range of values for an effective percentage of new vital bone formation at various time points when bovine xenografts are used.24–29 The earliest documented time point following extraction grafting is generally 6 months, and average regenerated bone values range from approximately 12.5% to 24%.24,25,30–33 This proof-of-principle case series of an equine-derived bone mineral matrix, with physical and chemical characteristics similar to those of other xenografts, was used for extraction site augmentation procedures to prepare for implant placement. Study outcomes included histomorphometric and histo-
logic findings at 6 months following grafting, which demonstrated newly regenerated bone surrounded by and in intimate contact with residual EBM particles. Active bridging between EBM particles with newly formed bone was routinely observed in the core biopsy specimens, and no evidence of an inflammatory cell infiltrate was found. Histomorphometric values of percentage vital bone proved comparable to reported mean values of bovine-derived bone mineral xenografts. With vital bone formation values ranging from 17.9% to 39.1%, and a mean value of 28.8%, EBM in this initial case series appears comparable to other bone mineral xenografts in terms of its osteoconductive ability to support new bone formation at 6 months in socket preservation procedures.27 Although the results of this study are promising, longer-term studies are needed to determine bone regeneration trends at later time points. In addition, clinical studies examining long-term implant survival under function are needed to gain a comprehensive understanding of the potential role of EBM for osteogenic procedures.
Conclusions Clinical and histologic evidence supported the suitability of EBM for extraction site augmentation, which resulted in subsequent dental implant placement after a 6-month healing period. There were no adverse events encountered with these procedures.
Acknowledgments This study was sponsored by a grant from Osteohealth. The authors reported no conflicts of interest related to this study.
References 1. Nevins M, Camelo M, Sergio DP, et al. A study of the fate of the buccal wall of extraction sockets of teeth with prominent roots. Int J Periodontics Restorative Dent 2006;26:19–29. 2. Klokkevold PR, Newman MG. Current status of dental implants: A periodontal perspective. Int J Oral Maxillofacial Implants 2000;15:56–65. 3. Mellonig JT, Nevins M. Guided bone regeneration of bone defects associated with implants: An evidence-based outcome assessment. Int J Periodontics Restorative Dent 1995;15:168–185. 4. Nevins M, Mellonig JT, Clem DS 3rd, Reiser GM, Buser DA. Implants in regenerated bone: Long-term survival. Int J Periodontics Restorative Dent 1998; 18:34–45. 5. Fiorellini JP, Howell TH, Cochran D, et al. Randomized study evaluating recombinant human bone morphogenetic protein-2 for extraction socket augmentation. J Periodontol 2005;76:605–613. 6. Carlsson H, Thilander H, Hedegard B. Histologic changes in the upper alveolar process after extractions with or without insertion of an immediate full denture. Acta Odontol Scand 1967;25:21–43. 7. Huebsch RF, Hansen LS. A histopathologic study of extraction wounds in dogs. Oral Surg Oral Med Oral Pathol 1969; 28:187–196. 8. Amler MH, Johnson PL, Salsman I. Histologic and histochemical investigation of human alveolar sockets healing in undisturbed extraction wounds. J Am Dent Assoc 1960;61:46–48. 9 Iasella JM, Greenwell H, Miller RL, et al. Ridge preservation with freeze-dried bone allograft and a collagen membrane compared to extraction alone for implant site development. J Periodontol 2003; 74:990–999. 10. Pietrokovski J, Massler M. Alveolar ridge resorption following tooth extraction. J Prosthet Dent 1967;17:21–27. 11. Cardaropoli G, Aravjo M, Lindhe J. Dynamics of bone tissue formation in tooth extraction sites. An experimental study in dogs. J Clin Periodontol 2003;30: 809–818.
The International Journal of Periodontics & Restorative Dentistry © 2014 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
s57
12. Johnson K. A study of the dimensional changes occurring in the maxilla following closed face immediate denture treatment. Aust Dent J 1969;14:370–376. 13. Araujo MG, Lindhe J. Dimensional ridge alterations following tooth extraction. An experimental study in the dog. J Clin Periodontol 2005;32:212–218. 14. Lam RV. Contour changes of the alveolar process following extraction. J Prosthet Dent 1960;10:25–32L 15. Schropp L, Wenzel A, Kostopoulos L, Karring T. Bone healing and soft tissue contour changes following single-tooth extraction: A clinical and radiographic 12-month prospective study. Int J Periodontics Restorative Dent 2003;23: 313–323. 16. Lekovic V, Kennev EB, Weinlaender M, et al. A bone regenerative approach to alveolar ridge maintenance following tooth extraction. Report of 10 cases. J Periodontol 1997;68:363–370. 17. Lekovic V, Camargo PM, Klokkevold PR, et al. Preservation of alveolar bone in extraction sockets using bioabsorbable membranes. J Periodontol 1998;69: 1044–1049. 18. Camargo PM, Lekovic V, Weinlaender M, et al. Influence of bioactive glass on changes in alveolar process dimensions after exodontias. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2000;90: 581–586. 19. Wallace SS, Froum SJ. Effect of maxillary sinus augmentation on the survival of endosseous dental implants. A systematic review. Ann Periodontol 2003;8:328–343. 20. Del Fabbro M, Testori T, Francetti I, et al. Systematic review of survival rates for implants placed in the grafted maxillary sinus. Int J Periodontics Restorative Dent 2004;24:565–577.
21. Del Fabbro M, Rosano G, Taschieri S. Implant survival rates after maxillary sinus augmentation. Eur J Oral Sci 2008; 116:497–506. 22. Del Fabbro M, Bortolin M, Taschieri S, et al. Implant survival after maxillary sinus augmentation. An updated systematic review. J Osteo Biomat 2010;1:69–79. Erratum in: J Osteol Biomat 2010;1:186. 23. Pjetursson BE, Tan WC, Zwahlen M, Lang NP. A systematic review of the success of sinus floor elevation and survival of implants inserted in combination with sinus floor elevation. Part I: Lateral approach. J Clin Periodontol 2008;35 (Suppl 8): 216–224. 24. Froum SJ, Wallace SS, Cho SC, Elian N, Tarnow DP. Comparison of mineralized cancellous allograft (Puros) and anorganic bovine bone matrix (Bio-Oss) for sinus augmentation: Histomorphometry at 26 to 32 weeks after grafting. Int J Periodontics Restorative Dent 2006;26:543–551. 25. Lee YM, Shin Sy, Kim JY, Kye SB, Ku Y, Rhyu IC. Bone reaction to bovine hydroxyapatite for maxillary sinus floor augmentation: Histologic results in humans. Int J Periodontics Restorative Dent 2006;26:471–481. 26. Froum SJ, Wallace SS, Cho SC, Elian N, Tarnow DP. Histomorphometric comparison of a biphasic bone ceramic to anorganic bovine bone for sinus augmentation: 6- to 8-month postsurgical assessment of vital bone formation. A pilot study. Int J Periodontics Restorative Dent 2008;28:273–281. 27. Nevins M, Camelo M, De Angelis N, et al. The clinical and histologic efficacy of xenograft granules for maxillary sinus floor augmentation. Int J Periodontics Restorative Dent 2011;31:227–235.
28. Zerbo IR, Zijdervels SA, de Boer A, et al. Histomorphometry of human sinus floor augmentation using a porous beta-tricalcium phosphate: A prospective study. Clin Oral Implants Res 2004;15:724–732. 29. Fugazzotto PA. GBR using bovine bone matrix and resorbable and nonresorbable membranes. Part 1: Histologic results. Int J Periodontics Restorative Dent 2003;23:361–369. 30. Wallace SS, Cho S-C, Monteiro D, Tarnow DP. Sinus augmentation utilizing anorganic bovine bone (Bio-Oss) with absorbable and nonabsorbable membranes placed over the lateral window: Histomorphometric and clinical analyses. Int J Periodontics Restorative Dent 2005; 25:551–559. 31. Froum SJ, Tarnow DP, Wallace SS, Roher MD, Cho S-C. Sinus floor elevation using anorganic bovine bone matrix (OteoGraf/N) with and without autogenous bone: A clinical, histologic, radiographic, and histomorphometric analysis – Part 2 of an ongoing prospective study. Int J Periodontics Restorative Dent 1998; 18:529–543. 32. Ferreira CEA, Novaes Jr AB, Haraszthy VI, et al. A clinical study of 406 sinus augmentations with 100% anorganic bovine bone. J Periodontol 2009;80:1920–1927. 33. Valentini P, Abensur D, Wenz B, et al. Sinus grafting with porous bone mineral (Bio-Oss) for implant placement: A 5-year study on 15 patients. Int J Periodontics Restorative Dent 2000;20:245–253.
Volume 34, Supplement, 2014 © 2014 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
