Tải bản đầy đủ - 0trang
12 Case 4 (Severe Labial Bone Loss with Moderate Gingival Recession)
P. R. Klokkevold
Fig. 5.15 Case presentation of an immediate implant placement with immediate (prefabricated) provisional restoration to replace an endodontically failing maxillary left central incisor, #9. (a)
Preoperative clinical photo of maxillary anterior teeth. Notice the maxillary left central incisor area has
drifted coronal and facial. There is a diastema between the right maxillary lateral and central incisor
with flattened interproximal tissue. (b) Preoperative sequential series of clinical photos demonstrating
the treatment steps including extraction, flap reflection, implant placement in palatal position utilizing
a computer-generated surgical guide, bone grafting labial dehiscence defect with particulate bone
allograft, placement of prefabricated provisional restoration, and placement of several layers of L-PRF
membrane. (c) Clinical photograph 1 year later after delivery of final restorations, including crown #8,
implant crown #9, and veneer #10 (Courtesy of Dr. Thomas Han and Dr. Todd Schoenbaum)
5 Soft Tissue Management for Implants in the Aesthetic Zone
Aesthetic failures frequently begin with an inadequate examination of the existing soft and hard tissues, which leads to an incorrect diagnosis and ultimately to
an inappropriate treatment plan. The wrong treatment plan combined with selection of inappropriate surgical approaches or techniques can result in poor aesthetic outcomes.
The clinical science in dentistry has evolved to where placement of dental
implants and restoring them requires sufficient knowledge in several disciplines
of dentistry. In addition to mastering surgical objectives and techniques, clinicians must be able to evaluate and accurately diagnose the existing periodontal
condition. Furthermore, proper restorative management of soft tissues is critical
to achieving and maintaining aesthetics. Hence, there are multiple aspects of
diagnosis that are essential for the development of an appropriate treatment plan
necessary for a successful outcome in aesthetic implant dentistry.
The soft tissue management and minimally invasive surgical approach to aesthetics presented in this chapter are based on sound biological principles and
offer a predictable way to preserve and enhance aesthetics of anterior partially
1.Gargiulo AW, Wentz FM, Orban B. Dimensions and relations of the dentogingival junction in
humans. J Periodontol. 1961;32:261–7.
2.Kan JY, Rungcharassaeng K, Umezu K, Kois JC. Dimensions of peri-implant mucosa: an
evaluation of maxillary anterior single implants in humans. J Periodontol. 2003;74:557–62.
3. Vacek JS, Gher ME, Assad DA, Richardson AC, Giambarresi LI. The dimensions of the human
dentogingival junction. Int J Periodontics Restorative Dent. 1994;14:154–65.
4.Tarnow DP, Magner AW, Fletcher P. The effect of the distance from the contact point to the
crest of bone on the presence or absence of the interproximal dental papilla. J Periodontol.
5. Martegani P, Silvestri M, Mascarello F, Scipioni T, Ghezzi C, Rota C, Cattaneo V. Morphometric
study of the interproximal unit in the esthetic region to correlate anatomic variables affecting
the aspect of soft tissue embrasure space. J Periodontol. 2007;78:2260–5.
6.Cho HS, Jang HS, Kim DK, Park JC, Kim HJ, Choi SH, Kim CK, Kim BO. The effects of
interproximal distance between roots on the existence of interdental papillae according to the
distance from the contact point to the alveolar crest. J Periodontol. 2006;77:1651–7.
7. Schoenbaum TR, Klokkevold PR, Chang YY. Immediate implant-supported provisional restoration with a root-form pontic for the replacement of two adjacent anterior maxillary teeth: a
clinical report. J Prosthet Dent. 2013;109:277–82.
8. Buser D, Bornstein MM, Weber HP, Grutter L, Schmid B, Belser UC. Early implant placement
with simultaneous guided bone regeneration following single-tooth extraction in the esthetic
zone: a cross-sectional, retrospective study in 45 subjects with a 2- to 4-year follow-up. J
9.Chen ST, Darby IB, Reynolds EC, Clement JG. Immediate implant placement postextraction
without flap elevation. J Periodontol. 2009;80:163–72.
10.Kan JY, Rungcharassaeng K, Lozada J. Immediate placement and provisionalization of
maxillary anterior single implants: 1-year prospective study. Int J Oral Maxillofac Implants.
11.Klokkevold PR, Han TJ, Camargo PM. Aesthetic management of extractions for implant site
development: delayed versus staged implant placement. Pract Periodontics Aesthet Dent.
1999;11:603–10. quiz 612.
P. R. Klokkevold
12.Azzi R, Takei HH, Etienne D, Carranza FA. Root coverage and papilla reconstruction
using autogenous osseous and connective tissue grafts. Int J Periodontics Restorative Dent.
13.Han TJ, Takei HH. Progress in gingival papilla reconstruction. Periodontol. 1996;11:65–8.
14.Takei HH, Han TJ, Carranza FA Jr, Kenney EB, Lekovic V. Flap technique for periodontal
bone implants. Papilla preservation technique. J Periodontol. 1985;56:204–10.
15.Lekovic V, Kenney EB, Weinlaender M, Han T, Klokkevold P, Nedic M, Orsini M. A bone
regenerative approach to alveolar ridge maintenance following tooth extraction. Report of 10
cases. J Periodontol. 1997;68:563–70.
16.Araujo MG, Lindhe J. Dimensional ridge alterations following tooth extraction. An experimental study in the dog. J Clin Periodontol. 2005;32:212–8.
17.Araujo MG, Wennstrom JL, Lindhe J. Modeling of the buccal and lingual bone walls of fresh
extraction sites following implant installation. Clin Oral Implants Res. 2006;17:606–14.
18.Hammerle CH, Araujo MG, Simion M, Osteology Consensus G. Evidence-based knowledge
on the biology and treatment of extraction sockets. Clin Oral Implants Res. 2012;23(Suppl
19.Tarnow D, Elian N, Fletcher P, Froum S, Magner A, Cho SC, Salama M, Salama H, Garber
DA. Vertical distance from the crest of bone to the height of the interproximal papilla between
adjacent implants. J Periodontol. 2003;74:1785–8.
20. Kois JC. Predictable single-tooth peri-implant esthetics: five diagnostic keys. Compend Contin
Educ Dent. 2004;25:895–6. 898, 900 passim; quiz 906–897.
21.Benic GI, Mokti M, Chen CJ, Weber HP, Hammerle CH, Gallucci GO. Dimensions of buccal bone and mucosa at immediately placed implants after 7 years: a clinical and cone beam
computed tomography study. Clin Oral Implants Res. 2012;23:560–6.
22. Miron RJ, Dard M, Weinreb M. Enamel matrix derivative, inflammation and soft tissue wound
healing. J Periodontal Res. 2015;50:555–69.
23.Rasperini G, Roccuzzo M, Francetti L, Acunzo R, Consonni D, Silvestri M. Subepithelial
connective tissue graft for treatment of gingival recessions with and without enamel matrix
derivative: a multicenter, randomized controlled clinical trial. Int J Periodontics Restorative
24. Hehn J, Schwenk T, Striegel M, Schlee M. The effect of PRF (platelet-rich fibrin) inserted with
a split-flap technique on soft tissue thickening and initial marginal bone loss around implants:
results of a randomized, controlled clinical trial. Int J Implant Dent. 2016;2:13.
25.Han TJ, Jeong CW. Bone and crescent shaped free gingival grafting for anterior immediate
implant placement: technique and case report. J Implant Adv Clin Dent. 2009;1:23–33.
26.Araujo MG, Sukekava F, Wennstrom JL, Lindhe J. Ridge alterations following implant
placement in fresh extraction sockets: an experimental study in the dog. J Clin Periodontol.
27.Nevins M, Camelo M, De Paoli S, Friedland B, Schenk RK, Parma-Benfenati S, Simion M,
Tinti C, Wagenberg B. 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.
28.Chiapasco M, Consolo U, Bianchi A, Ronchi P. Alveolar distraction osteogenesis for the correction of vertically deficient edentulous ridges: a multicenter prospective study on humans.
Int J Oral Maxillofac Implants. 2004;19:399–407.
29. Covani U, Cornelini R, Barone A. Bucco-lingual bone remodeling around implants placed into
immediate extraction sockets: a case series. J Periodontol. 2003;74:268–73.
30.Schropp L, Kostopoulos L, Wenzel A. Bone healing following immediate versus delayed
placement of titanium implants into extraction sockets: a prospective clinical study. Int J Oral
Maxillofac Implants. 2003;18:189–99.
31.Allen EP, Gainza CS, Farthing GG, Newbold DA. Improved technique for localized ridge
augmentation. A report of 21 cases. J Periodontol. 1985;56:195–9.
32. Seibert JS. Treatment of moderate localized alveolar ridge defects. Preventive and reconstructive concepts in therapy. Dent Clin N Am. 1993;37:265–80.
5 Soft Tissue Management for Implants in the Aesthetic Zone
33.Kan JY, Rungcharassaeng K, Lozada JL. Bilaminar subepithelial connective tissue grafts for
immediate implant placement and provisionalization in the esthetic zone. J Calif Dent Assoc.
34. Khzam N, Arora H, Kim P, Fisher A, Mattheos N, Ivanovski S. Systematic review of soft tissue
alterations and esthetic outcomes following immediate implant placement and restoration of
single implants in the anterior maxilla. J Periodontol. 2015;86:1321–30.
35. Kan JY, Rungcharassaeng K. Site development for anterior single implant esthetics: the dentulous site. Compend Contin Educ Dent. 2001;22:221–6. 228, 230-221; quiz 232.
36. Bengazi F, Wennstrom JL, Lekholm U. Recession of the soft tissue margin at oral implants. A
2-year longitudinal prospective study. Clin Oral Implants Res. 1996;7:303–10.
37.Grunder U. Stability of the mucosal topography around single-tooth implants and adjacent
teeth: 1-year results. Int J Periodontics Restorative Dent. 2000;20:11–7.
38.Nozawa T, Enomoto H, Tsurumaki S, Ito K. Biologic height-width ratio of the buccal supra-
implant mucosa. Eur J Esthet Dent. 2006;1:208–14.
39.Kan JY, Rungcharassaeng K, Lozada JL, Zimmerman G. Facial gingival tissue stability following immediate placement and provisionalization of maxillary anterior single implants: a
2- to 8-year follow-up. Int J Oral Maxillofac Implants. 2011;26:179–87.
Growth Factors for Site Preparation:
Current Science, Indications,
Tara Aghaloo and Rachel Lim
Implant restoration of the dentition poses many challenges in cases of limited
bony foundation. Many patients suffer from loss of teeth and supporting bony
structures through mechanisms including trauma, congenital abnormalities, or
resorption secondary to tooth loss. In addition to classic alveolar ridge augmentation techniques and materials, growth factors are being studied to improve
patient outcomes, especially in cases of larger, more challenging defects, in previously failed graft sites, and in stringent aesthetic cases. In this chapter, we will
discuss three growth factors which are most commonly studied and US Food and
Drug Administration approved: bone morphogenetic protein-2 (BMP-2), platelet-derived growth factor (PDGF), and platelet-rich protein/platelet-rich fibrin
(PRP/PRF). Currently, growth factors are utilized in a wide variety of clinical
situations, including guided bone regeneration, peri-implant defects, sinus augmentation, and socket augmentation. Furthermore, we will explore the future of
growth factor usage, with new factors in various stages of investigation, combinations of materials, and viable cell therapy. Though much work has been done
in the last few decades to reveal the clinical relevance of growth factors, much
more research, both basic and clinical, must be performed to improve current
technologies, develop predictable protocols, and evaluate long-term results.
T. Aghaloo (*)
Section of Oral and Maxillofacial Surgery, UCLA School of Dentistry,
Los Angeles, CA, USA
Department of Oral and Maxillofacial Surgery, University of Washington, Seattle,
© Springer International Publishing AG, part of Springer Nature 2019
Todd R. Schoenbaum (ed.), Implants in the Aesthetic Zone,
T. Aghaloo and R. Lim
Many patients suffer from significant loss of the periodontium and surrounding
bony structures through mechanisms including periodontal disease, trauma, congenital abnormalities, tumors, or resorption secondary to tooth loss. In these situations, achieving a stable site for reconstruction through implant placement can pose
clinical challenges and may require augmentation to optimize the supporting structures . Furthermore, aesthetic zone sites require more stringent planning, with
factors such as gingival biotype and space limitations significantly affecting the
final result, and in which proper placement of the implant is paramount to an ideal
outcome . In smaller bony defects, successful treatment with guided bone regeneration (GBR; see Chap. 4) using autografts, allografts, or xenografts has been well
documented . However, larger or more challenging defects in previously failed
graft sites or implant sites in medically compromised patients will require more
complex therapy to achieve a successful outcome. In such cases, traditional techniques and materials may not achieve sufficient bone regeneration, compromising
the prosthetic rehabilitation and final outcome.
One of the main techniques that have been implemented since its development in
the 1980s is guided bone regeneration, which has resulted in predictable regeneration of contained defects through usage of grafting materials and/or barrier membranes [1, 3]. In cases requiring significant bone regeneration, secondary techniques
have been employed concurrently with GBR to overcome limitations of scaffold
material and to recruit the desired cell types for regeneration. Over the past decade,
molecular mediators, such as growth factors, have been extensively studied for their
potential to combat challenging clinical scenarios by accelerating the healing process and aid in regeneration of the missing maxillofacial tissues . Growth factors
naturally occur in the body and are capable of stimulating growth, proliferation, and
differentiation of cells. Growth factors regulate many of the key cellular events that
are required for tissue repair and regeneration. The clinical application of these
biologic agents aims to provide faster healing, implant osseointegration, and expedited establishment of functionality. Currently, growth factors are utilized in a wide
variety of clinical situations including intrabony defects, barrier membranes for
GBR, peri-implant defects, sinus augmentation, and socket augmentation. In this
chapter, we will focus on US Food and Drug Administration (FDA)-approved
growth factors: bone morphogenetic protein (BMP-2), platelet-derived growth factor (PDGF), and platelet-rich plasma (PRP)/platelet-rich fibrin (PRF).
Bone forms through three distinct mechanisms, and bone grafting materials are
classified based on their ability to activate these mechanisms. Osteoconductive
materials possess the ability to passively act as a scaffold and allow substitution of
new bone. Osteoconduction requires good surrounding bone that can be resorbed
and replaced with new native bone from the host. Although osteoconductive materials are readily available and inexpensive, large and complex bone defects or medically compromised patients with poor healing potential generally cannot regenerate
bone from only scaffold grafting material. Osteoinductive materials can actively
recruit undifferentiated mesenchymal stem cells to the graft site and stimulate
6 Growth Factors for Site Preparation: Current Science, Indications, and Practice
osteoblastic differentiation. Bringing these cells to the site and driving bone formation is a huge advantage of inductive materials. However, most off the shelf bone
grafts do not contain these properties. Osteogenic materials transplant live bone
cells which can actively form new bone at the recipient site . Osteogenesis is the
most powerful of the three mechanisms, but only autogenous bone possesses these
properties. Unfortunately, not all patients are candidates for autogenous bone harvesting since it often requires a second surgical site, increased morbidity, and longer
surgical time. When determining the appropriate growth factor for a specific patient,
evaluating the bone or soft tissue enhancing properties of the material is important.
Since no graft material can possess all the ideal properties—biocompatibility, biodegradability, promotion of vascularity, mechanical properties similar to bone,
selectivity for osteogenic cell adherence and survival, ease of manipulation, availability, and low cost—growth factors may improve or enhance our currently utilized
Bone Morphogenetic Protein-2 (BMP-2)
Bone morphogenetic proteins (BMPs) are secreted glycoproteins that belong to the
transforming growth factor-beta (TGF-β) superfamily. These glycoproteins are classified as morphogens, with roles in dictating tissue patterning in embryonic development, and are potent regulators of bone and cartilage formation and repair. Many
studies have demonstrated that BMP’s can induce mesenchymal stem cell differentiation into bone and cartilage, making them promising molecules for tissue engineering and bone therapy . In 1965, Urist first discovered BMP as a substance in
the extracellular bone matrix which was capable of inducing ectopic osteogenesis
when implanted in extraskeletal rabbit muscle pouches . Since the classification
of BMP’s in the late 1980s, more than 20 members have been identified, though not
all are osteogenic [8, 9]. Specifically, BMP-2 is most commonly utilized for its
osteoinductive properties, which allows it to actively promote chemotaxis to the
graft site and stimulate osteoblastic differentiation and bone formation [10, 11].
BMP-2 has been extensively studied and increasingly applied in orthopedic surgery
to improve the results of bone therapy. In 2002, recombinant human BMP-2 and
BMP-7 (rhBMP-2 and rhBMP-7) were approved by the FDA for orthopedic applications including (1) promoting fusion of lower spine vertebrae, (2) acute tibia fractures, and (3) tibia nonunion . As patients become more medically compromised
or when conventional grafting techniques fail, growth factors have been utilized for
new applications such as posttraumatic osteonecrosis of the femoral head .
In oral and maxillofacial reconstruction, BMP-2 has demonstrated ability to control bone formation, contour, and density through endochondral formation .
Randomized clinical trials demonstrate predictable bone formation in localized
alveolar bone defects associated with tooth extraction and sinus augmentation when
placed on an absorbable collagen sponge (ACS) [14–16]. These successes led to
FDA approval for these dental indications in 2007 (Infuse, Medtronic, Nashville,
TN). Since its approval, clinicians and researchers continue to expand the off-label
T. Aghaloo and R. Lim
uses of rhBMP-2/ACS to include onlay grafting, lateral ridge augmentation, extensive maxillofacial reconstruction, and mandibular continuity defects (Fig. 6.1) [4,
17–25]. These more complicated defects generally require a more compressive
resistant scaffold (such as titanium mesh) [26, 27].
rhBMP-2/ACS is often combined with a xenograft or allograft for alveolar ridge
or sinus augmentation, resulting in further off-label utilization (Fig. 6.1) [27–32]. In
addition, improved soft tissue compression resistance can be obtained by combining
rhBMP-2/ACS with additional graft materials or titanium mesh. Specifically, combination with osteoconductive materials may decrease the BMP-2 dose needed to
regenerate bone defects. Clinically FDA-approved supraphysiologic BMP-2 doses
have been associated with many side effects including major swelling, inflammation, seromas, wound breakdown, heterotopic bone formation, cystic bone cavities,
immunogenicity, BMP antibody formation, osteolysis through osteoclast activation,
and bone cyst formation [33–39]. Currently, BMP-2 use for oral and maxillofacial
defects has not been optimized due to high costs, nonideal carriers, and suboptimal
bone formation, resulting in limited clinical use. However, in patients with
Fig. 6.1 rhBMP-2 for anterior maxillary ridge augmentation. (a) Buccal and (b) occlusal view of
resorbed alveolar ridge with temporary fixed partial denture. (c) Clinical and (d) radiographic
(CBCT cone-beam CT scan) preoperative alveolar ridge. (e) After flap reflection, (f) cortical bone
decortication is performed to release undifferentiated mesenchymal stem cells from the trabecular
bone that can respond to the rhBMP-2. (g) rhBMP-2/ACS is combined with autograft and alloplast
grafting materials and covered with a (h) BMP-2 sponge before (i) titanium mesh is applied to
resist soft tissue compression. (j) Wound healing after 7 months and (k) CBCT scan before implant
placement. (l) Titanium mesh is seen at the time of implant placement for removal and reveals (m)
an increased volume of bone for (n) implant placement. (o) Adequate ridge dimensions are seen,
and (p) soft tissue coverage is performed without difficulty