Bone grafting after tooth removal: Why, when, and what to use

Dr. Scott Froum discusses tooth extraction prevalence in the US and offers a decision matrix to clarify when bone grafting is needed and the best type of material for site preservation.

Figure 1: Site No. 29 was extracted one year prior to the photo, resulting in severe ridge resorption and the need for ridge augmentation prior to dental implant treatment.
Figure 1: Site No. 29 was extracted one year prior to the photo, resulting in severe ridge resorption and the need for ridge augmentation prior to dental implant treatment.

Tooth extraction is a common practice in the United States, with a prevalence of roughly 50% of adults in the age range of 20–64 having at least one tooth extracted.1 The normal pattern of bone healing following tooth extraction is resorptive, typically leaving both hard- and soft-tissue defects in the alveolus without site preservation and/or tissue grafting.2 This is problematic for various reasons. Loss of tissue structure in the jaw directly affects the functional and esthetic outcomes of dental implants as well as tooth-borne fixed prosthetics (dental bridges).Figure 2: Loss of both hard and soft tissue in a horizontal and vertical dimensionFigure 2: Loss of both hard and soft tissue in a horizontal and vertical dimension

Why bone grafting?

Although unpredictable, a greater amount of alveolar ridge loss following extraction usually occurs in the horizontal dimension and affects the buccal bone of the ridge.3 In fact, 50% of alveolar bone dimension can be lost after tooth extraction, with losses reported of up to 6–7 mm (figure 1). Two-thirds of this loss of bone volume can occur within the first three months of tooth extraction.4Figure 3: Abscess at the apex of implant No. 10 placed two years ago. The tooth was removed and the site was not preserved with graft material. The implant was placed six months after tooth removal.Figure 3: Abscess at the apex of implant No. 10 placed two years ago. The tooth was removed and the site was not preserved with graft material. The implant was placed six months after tooth removal.

Loss of vertical ridge height can also occur and usually takes place along the buccal aspect of the ridge to a lesser degree than horizontal ridge loss.5 Corresponding reductions in vertical ridge height ranging from 2–4 mm have been noted.6 The combination of this resorptive pattern results in a ridge that has moved in a palatal/lingual direction and has atrophied vertically (figure 2).Figure 4: Flap surgery of the implant showing fenestration of the implant through the buccal wall due to deficient bone volumeFigure 4: Flap surgery of the implant showing fenestration of the implant through the buccal wall due to deficient bone volume

These alveolar bone changes often compromise implant placement due to thin bone volume (figures 3–6).Figure 5: Buccal bone of implant was augmented with Geistlich Bio-Oss Collagen to save the implant from explantation.Figure 5: Buccal bone of implant was augmented with Geistlich Bio-Oss Collagen to save the implant from explantation.

Reduction in quantity and quality of bone can also compromise functional and esthetic outcomes of both implants and fixed bridge restorations (figures 7 and 8).Figure 6: Final implant after it was stabilized with ridge augmentationFigure 6: Final implant after it was stabilized with ridge augmentation

When to use bone grafting?

Because of this alveolar resorptive pattern after tooth extraction, bone grafting the extraction socket after tooth extraction procedures has become a solution that attempts to limit the amount of hard- and soft-tissue loss. There are many systematic reviews in the literature that compare the results of residual ridge dimension following tooth extraction after the use of a bone graft (with or without a membrane) versus extraction alone without grafting.7 Figure 7: Prosthetic (pink) porcelain needed on an implant bridge to mask hard- and soft-tissue lossFigure 7: Prosthetic (pink) porcelain needed on an implant bridge to mask hard- and soft-tissue lossSockets that were preserved with bone grafting and/or membrane on average lost 2 mm less of ridge width, 1 mm less of ridge height, and had 20% more bone volume when compared to sockets that were not grafted.8 Maxillary sites lost more than mandibular sites, and most ridge resorption occurred on the buccal aspect of the ridge.Figure 8: Soft- and hard-tissue loss on a tooth-borne bridge after extraction without grafting, resulting in an unesthetic restorationFigure 8: Soft- and hard-tissue loss on a tooth-borne bridge after extraction without grafting, resulting in an unesthetic restoration

Indications for bone grafting extraction sites include:

site development to increase hard and soft tissue for pontic sites in fixed bridge prosthetics (figures 9–14);Figure 9: Severe bone and soft-tissue loss after extraction without grafting would force the pontic of this bridge to be long and unesthetic.Photo courtesy of Michael J. Wei, DDS, FIADFE.Figure 9: Severe bone and soft-tissue loss after extraction without grafting would force the pontic of this bridge to be long and unesthetic.Photo courtesy of Michael J. Wei, DDS, FIADFE.

Figure 10: Collapse of hard and soft tissue under fixed bridge after tooth extraction without grafting. Photo courtesy of Michael J. Wei, DDS, FIADFE.Figure 10: Collapse of hard and soft tissue under fixed bridge after tooth extraction without grafting. Photo courtesy of Michael J. Wei, DDS, FIADFE.Figure 12: Pontic site development with Geistlich Bio-Oss Collagen and Geistlich Bio-GideFigure 12: Pontic site development with Geistlich Bio-Oss Collagen and Geistlich Bio-GideFigure 13: Final bridge insertion after pontic site development. Photo courtesy of Michael J. Wei, DDS, FIADFE.Figure 13: Final bridge insertion after pontic site development. Photo courtesy of Michael J. Wei, DDS, FIADFE.Figure 10: Collapse of hard and soft tissue under fixed bridge after tooth extraction without grafting. Photo courtesy of Michael J. Wei, DDS, FIADFE.Figure 10: Collapse of hard and soft tissue under fixed bridge after tooth extraction without grafting. Photo courtesy of Michael J. Wei, DDS, FIADFE.rebuilding defects around adjacent teeth after extracting teeth due to periodontal disease (figures 15–17);

correcting bone defects impinging upon anatomical structures after tooth extraction, such as oroantral communication (figure 18); and

preserving tissue structure for subsequent dental implant therapy.Figure 14: Final picture of smileFigure 14: Final picture of smile

Decision matrix

With these indications in mind, does every extraction socket need to be grafted? The answer is no. A good decision matrix is based on “A Simplified Socket Classification and Repair Technique” by Elian et al.9Figure 15: Radiograph of severe bone defect after tooth extraction with bone loss affecting adjacent teethFigure 15: Radiograph of severe bone defect after tooth extraction with bone loss affecting adjacent teeth

Figure 16: Site augmentation with Geistlich Bio-Oss Collagen and collagen membraneFigure 16: Site augmentation with Geistlich Bio-Oss Collagen and collagen membraneFigure 18: Image of tooth with large infection that will require bone graft after extraction to keep sinus intact and from pneumatizingFigure 18: Image of tooth with large infection that will require bone graft after extraction to keep sinus intact and from pneumatizingFigure 16: Site augmentation with Geistlich Bio-Oss Collagen and collagen membraneFigure 16: Site augmentation with Geistlich Bio-Oss Collagen and collagen membranesfds

Classification when existing tooth is still present

Type 1 socket—Buccal plate present and soft tissue present

• Type 1a socket (figure 19)—Thick biotype, posterior tooth, and buccal plate present: no graft neededFigure 19: Type 1a socketFigure 19: Type 1a socket

• Type 1b socket (figure 20)—Thick biotype, anterior tooth, and buccal plate present: clot stabilizerFigure 20: Type 1b socketFigure 20: Type 1b socket

• Type 1c socket (figure 21)—Thin biotype, anterior or posterior, and buccal plate present: bone graftFigure 21: Type 1c socketFigure 21: Type 1c socket

• Type 2 socket (figures 22 and 23)—Buccal plate missing, but soft tissue present: bone graft +/- membrane (if graft containment is needed)Figure 22: Type 2 socketFigure 22: Type 2 socket

Figure 23: Type 2 socket after tooth extraction, showing loss of buccal plateFigure 23: Type 2 socket after tooth extraction, showing loss of buccal plate • Type 3 socket (figure 24)—Buccal plate missing and soft tissue missing: bone graft + membrane +/- biologic agent (consider soft-tissue graft if keratinized tissue is less than 2 mm)Figure 24: Type 3 socket with buccal plate and soft-tissue lossFigure 24: Type 3 socket with buccal plate and soft-tissue loss

What bone grafting product?

Although there are many types of grafting products commercially available, choosing the right one may be difficult. An ideal bone graft substitute should be biomechanically stable; able to degrade within an appropriate time frame; exhibit osteoconductive, osteogenic, and osteoinductive properties; and provide a favorable environment for invading blood vessels and bone-forming cells.10Figure 25: Radiograph of site No. 30, 12 months after bone graftFigure 25: Radiograph of site No. 30, 12 months after bone graft The graft material used should facilitate the three tenets of bone regeneration: clot stability, space maintenance, and blood supply/bone-forming cells.11 Unfortunately, many clinicians assume all grafting products are created equal and select the material based on price point alone. If the bone grafting material is not formulated correctly, degradation may not occur, and the graft can become fibrously encapsulated, leading to poor bone turnover and graft failure (figures 25–27).Figure 26: CT scan of bone graft showing poor graft healing and fibrous encapsulationFigure 26: CT scan of bone graft showing poor graft healing and fibrous encapsulation

One particularly good bone graft material that provides scaffolding space maintenance as well as stabilizes the blood clot is Geistlich Bio-Oss Collagen (Geistlich Pharmaceuticals).12 Geistlich Bio-Oss
Collagen is 90% Bio-Oss granules (size range 0.25–1.0 mm) and 10% collagen. The proprietary formulation of the collagen component gives the material its scaffolding and moldability qualities, which makes it an excellent product for site preservation after tooth extraction, especially during flapless site preservation.13 Finally, this graft material has been shown to outperform other graft materials in comparative studies looking at site preservation after tooth extraction.14Figure 27: Surgery of graft with poor healing and need to be removed and regraftedFigure 27: Surgery of graft with poor healing and need to be removed and regrafted

Editor’s note: This article originally appeared in Dental Economics’ partner publication Perio-Implant Advisory, a chairside resource for dentists and dental hygienists for issues relating to periodontal and implant medicine. Visit perioimplantadvisory.com to sign up for a newsletter subscription.

Read more about bone grafts in “A review of bone graft material” by Adam Bear, DDS, on the PIA website.

References

1. Dye BA, Thornton-Evans G, Li X, Iafolla TJ. Dental caries and tooth loss in adults in the United States, 2011–2012. NCHS data brief, No. 197. Hyattsville, MD: National Center for Health Statistics; 2015. https://www.cdc.gov/nchs/data/databriefs/db197.pdf.

2. Agarwal G, Thomas R, Mehta D. Postextraction maintenance of the alveolar ridge: rationale and review. Compend Cont Educ Dent. 2012;33(5):320-324; quiz 327, 336.

3. Hansson S, Halldin S. Alveolar ridge resorption after tooth extraction: A consequence of a fundamental principle of bone physiology. J Dent Biomech. 2012;3:1758736012456543. doi:10.1177/1758736012456543.

4. 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(4):313-323.

5. Lekovic V, Camargo PM, Klokkevold PR, et al. Preservation of alveolar bone in extraction sockets using bioabsorbable membranes. J Periodontol. 1998;69(9):1044-1049. doi: 10.1902/jop.1998.69.9.1044.

6. Lam RV. Contour changes of the alveolar processes following extraction. J Prosthet Dent. 1960;10:25-32.

7. Avila-Ortiz G, Elangovan S, Kramer KW, Blanchette D, Dawson DV. Effect of alveolar ridge preservation after tooth extraction: a systematic review and meta-analysis. J Dent Res. 2014;93(10):950-958. doi:10.1177/0022034514541127.

8. Aimetti M, Manavella V, Corano L, Ercoli E, Bignardi C, Romano F. Three‐dimensional analysis of bone remodeling following ridge augmentation of compromised extraction sockets in periodontitis patients: a randomized controlled study. Clin Oral Implants Res. 2018;29(2):202-214. doi:10.1111/clr.13099. Epub November 17, 2017.

9. Elian N, Cho SC, Froum S, Smith RB, Tarnow DP. A simplified socket classification and repair technique. Pract Proced Aesthet Dent. 2007;(19)2:99-104; quiz 106.

10. Janicki P, Schmidmaier G. What should be the characteristics of the ideal bone graft substitute? Combining scaffolds with growth factors and/or stem cells. Injury. 2011;42(suppl 2):S77-S81.

11. Mellonig JT, Triplett RG. Guided tissue regeneration and endosseous dental implants. Int J Periodontics Restorative Dent. 1993;13(2):108-119.

12. Araújo Mauricio, Linder E, Wennström J, Lindhe J. The influence of Bio-Oss Collagen on healing of an extraction socket: an experimental study in the dog. Int J Periodontics Restorative Dent. 2008;28(2):123-135.

13. Cardaropoli D, Tamagnone L, Roffredo A, De Maria A, Gaveglio L. Alveolar ridge preservation using tridimensional collagen matrix and deproteinized bovine bone mineral in the esthetic area: a CBCT and histologic human pilot study. Int J Periodontics Restorative Dent. 2018;38(suppl):S29-S35. doi:10.11607/prd.3702.

14. Scheyer ET, Heard R, Janakievski J, et al. A randomized, controlled, multicentre clinical trial of post‐extraction alveolar ridge preservation. J Clin Periodontol. 2016;43(12):1188-1199. doi:10.1111/jcpe.12623.

SCOTT FROUM, DDS, a graduate of the State University of New York, Stony Brook School of Dental Medicine, is a periodontist in private practice at 1110 2nd Avenue, Suite 305, New York City, New York. He is the editorial director of Perio-Implant Advisory and serves on the editorial advisory board of Dental Economics. Contact him through his website at drscottfroum.com or (212) 751-8530.

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