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9 Create and Maintain a Space for Bony Ingrowth

9 Create and Maintain a Space for Bony Ingrowth

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4  Guided Bone Regeneration (GBR) for Implants in the Aesthetic Zone



89



provided to the site. If the membrane selected is not able to maintain the desired

space, it may affect the outcome of the grafting procedure. Flexible membranes

such as those made of resorbable collagen may need the support of fixation pins or

tenting screws to provide adequate space for successful regeneration.



4.10 Occlusivity

The occlusivity of the membrane is determined by its porosity and the ability to

avoid fibrous tissue formation within the site. On the other hand, membrane

pores facilitate the diffusion of critical fluids, oxygen, and nutrients from the

periosteum, which are vital for bone formation. Large pores will allow the penetration of faster-moving cells (epithelial cells or gingival fibroblasts) and provide an easier pathway for bacterial contamination. If the pores are too small, on

the other hand, it may inhibit nutrient exchange to the site. Currently available

membranes for GBR contain pores that allow nutrient exchange while excluding

soft tissue cells.



4.11 Tissue Integration

Tissue integration is key in stabilizing the healing wound process. The barrier membrane must be able to adapt to the borders of the neighboring bone. A membrane

that is too stiff is not able to adapt to the contours of the recipient site. Poorly

adapted membranes cannot fully prevent migration of soft tissues into the graft site

and are more likely to perforate through the flaps during healing.



4.12 Clinical Manageability

Barrier membranes need to be manageable during the surgical procedure. If a membrane is too stiff, it may not be easily contoured, and its sharp edges are more likely

to lead to perforation of the soft tissue. On the other hand, softer membranes are

more difficult to handle once hydrated.



4.13 Suturing Principles for GBR

Adequate approximation and closure of the wound edges is fundamental to successful GBR procedures and requires the use of sutures. Sutures should be biocompatible, retain adequate strength during the critical period of healing, and induce

minimal tissue reactions [29]. Sutures are made from resorbable or non-resorbable

materials and may be fabricated by either mono- or multifilament fibers [30]. Studies

have shown that multifilament, braided sutures (i.e., silk) are more likely to be contaminated by bacteria than monofilament sutures [31, 32], which induces increased

inflammation.



90



J. Pi-Anfruns and B. Le



Fig. 4.5  Closure of flap

following GBR for

horizontal augmentation

provided by one horizontal

mattress suture in the

center of the wound and

two single interrupted

sutures at the wound edges



Another important aspect of suturing is tension control. High tensions exerted by

sutures and applied to the wound edges may lead to tearing of the soft tissue margins [33]. These soft tissue dehiscences may prolong the healing time [34], cause

additional resorption of the underlying bone [35], jeopardize the healing results

[36], create irregular soft tissue contours, and result in an overall reduction of the

final graft volume.

Vascularity of the wound edges is another key factor for successful wound closure. Sutures that are placed too tight and in high quantities will compromise the

microperfusion and restrict blood supply. Reduced blood supply to the wound edges

will compromise the success of GBR treatment.

Closure of the flaps in GBR should be achieved first with horizontal mattress

sutures to create two contact surfaces of at least 3 mm thick, followed by alternating

single interrupted sutures [37] (Fig 4.5).



4.14 Postoperative Care

Following guided bone regeneration procedures, as with any bone grafting procedure, oral antibiotics and pain medication should be prescribed to prevent infection

and manage postoperative pain.

Postoperative edema, hematoma, and bleeding are common with GBR, and

patients should be advised accordingly. Patients should avoid using a toothbrush

directly around the wound for at least 1 week to prevent wound dehiscence. Rinses

with a bacteriostatic/bactericidal agent are recommended to minimize bacterial

accumulation on sutures.

A non-chewing diet should be recommended, and the use of a removable prosthesis over the grafted site is strongly discouraged. Unless otherwise indicated,

follow-ups should occur at 1–2  weeks after surgery to monitor wound healing.

Sutures should not be removed before 1 week, and it is recommended to maintain

them for 2 weeks whenever possible.



4  Guided Bone Regeneration (GBR) for Implants in the Aesthetic Zone



91



4.15 Complications and Management

Wound dehiscence and membrane exposure is the most commonly reported complication in GBR procedures [38], followed by infection [39]. In order to prevent

wound dehiscence, several factors may be considered:



4.15.1 Preoperative Factors

Some systemic diseases like diabetes mellitus and chronic corticosteroid therapy

will jeopardize healing. Social habits like smoking, excess alcohol consumption,

and recreational drug use can also interfere in the wound healing process. Patients

in this group should be instructed on proper oral hygiene habits prior to surgery to

minimize plaque accumulation and bacterial contamination.



4.15.2 Intraoperative Factors

As with any other surgical procedure, adequate flap design and clean and sharp incisions should be considered. Adequate muscle and flap release should allow sufficient flap elongation to achieve tension-free closure. Moreover, soft tissues should

be handled gently to prevent tearing. As discussed, adequate barrier fixation and

mattress sutures will prevent displacement of the membrane and further prevent

wound dehiscence.



4.15.3 Postoperative Factors

Instruction of proper oral hygiene habits will minimize plaque accumulation and

bacterial contamination during the postoperative period. Antibiotic and anti-inflammatory medication can reduce the chances of infection and reduce wound tension.

Removable prosthesis that applies pressure to the site should be avoided to minimize movement of the membrane and graft.



References

1. Melcher AH. On the repair potential of periodontal tissues. J Periodontol. 1976;47(5):256–60.

2.Nyman S, et al. New attachment following surgical treatment of human periodontal disease. J

Clin Periodontol. 1982;9(4):290–6.

3.Dahlin C, et al. Healing of bone defects by guided tissue regeneration. Plast Reconstr Surg.

1988;81(5):672–6.



92



J. Pi-Anfruns and B. Le



4. Simion M, Trisi P, Piattelli A. Vertical ridge augmentation using a membrane technique associated with osseointegrated implants. Int J Periodontics Restorative Dent. 1994;14(6):496–511.

5. Burkhardt R, Lang NP. Role of flap tension in primary wound closure of mucoperiosteal flaps:

a prospective cohort study. Clin Oral Implants Res. 2010;21:50–4.

6.Lee SH, Lim P, Yoon HJ.  The influence of cortical perforation on guided bone regeneration using synthetic bone substitutes: a study of rabbit cranial defects. Int J Oral Maxillofac

Implants. 2014;29:464–71.

7.Nishimura I, Shimizu Y, Ooya K. Effects of cortical bone perforation on experimental guided

bone regeneration. Clin Oral Implants Res. 2004;15:293–300.

8.Hämmerle CH, Schmid J, Lang NP, Olah AJ. Temporal dynamics of healing in rabbit cranial

defects using guided bone regeneration. J Oral Maxillofac Surg. 1995;53:167–74.

9.Cha JK, Kim CS, Choi SH, Cho KS, Chai JK, Jung UW.  The influence of perforating the

autogenous block bone and the recipient bed in dogs. Part II: histologic analysis. Clin Oral

Implants Res. 2012;23:987–92.

10.Shapiro F. Cortical bone repair. The relationship of the lacunar-canalicular system and intercellular gap junctions to the repair process. J Bone Joint Surg Am. 1988;70:1067–81.

11.Siddiqui NA, Owen JM.  Clinical advances in bone regeneration. Curr Stem Cell Res Ther.

2013;8:192.

12.Roberts TT, Rosenbaum AJ.  Bone grafts, bone substitutes and orthobiologics: the bridge

between basic science and clinical advancements in fracture healing. Organogenesis.

2012;8:114.

13.Einhorn TA.  The cell and molecular biology of fracture healing. Clin Orthop Relat Res.

1998;355:S7.

14.Aghaloo T, Felsenfeld AL. Principles of repair and grafting of bone and cartilage. In: Bagheri

SC, Horswell BB, Khan HA, editors. Current therapy in oral and maxillofacial surgery.

Philadelphia: Saunders; 2012.

15.Ulma R, Aghaloo T, Freymiller E. Wound healing. In: Fonseca RJ, Barber HD, Powers MP,

Frost DE, editors. Oral and maxillofacial trauma. 4th ed. St. Louis: Elsevier; 2013. p. 9.

16.Urban IA, Nagursky H, Lozada JL, Nagy K. Horizontal ridge augmentation with a collagen

membrane and a combination of particulated autogenous bone and anorganic bovine bonederived mineral: a prospective case series in 25 patients. Int J Periodontics Restorative Dent.

2013;33:299.

17.Rickert D, Sauerbier S, Nagursky H, Menne D, Vissink A, Raghoebar GM. Maxillary sinus

floor elevation with bovine bone mineral combined with either autogenous bone or autogenous

stem cells: a prospective randomized clinical trial. Clin Oral Implants Res. 2011;22:251.

18.LeGeros RZ.  Properties of osteoconductive biomaterials: calcium phosphates. Clin Orthop

Relat Res. 2002;395:81–98.

19.Mordenfeld A, Hallman M, Johansson CB, Albrektsson T.  Histological and histomorphometrical analyses of biopsies harvested 11 years after maxillary sinus floor augmentation with

deproteinized bovine and autogenous bone. Clin Oral Implants Res. 2010;21(9):961–70.

20. Lundgren S, Cricchio G, Hallman M, Jungner M, Rasmusson L, Sennerby L. Sinus floor elevation procedures to enable implant placement and integration: techniques, biological aspects

and clinical outcomes. Periodontol. 2017;73(1):103–20.

21. Karageorgiou V, Kaplan D. Porosity of 3D biomaterial scaffolds and osteogenesis. Biomaterials. 2005;26:5474–91.

22.Hannink G, Arts JJC. Bioresorbability, porosity and mechanical strength of bone substitutes:

what is optimal for bone regeneration? Injury. 2011;42:S22–5.

23.Hing KA. Bioceramic bone graft substitutes: influence of porosity and chemistry. Int J Appl

Ceram Technol. 2005;2:184–99.

24.Blokhuis TJ, Termaat MF, den Boer FC, Patka P, Bakker FC, Haarman HJ. Properties of calcium phosphate ceramics in relation to their in vivo behavior. J Trauma. 2000;48:179–86.

25.Boyne PJ, Cole MD, Stringer D, Shafqat JP. A technique for osseous restoration of deficient

edentulous maxillary ridges. J Oral Maxillofac Surg. 1985;43:87–91.



4  Guided Bone Regeneration (GBR) for Implants in the Aesthetic Zone



93



26.Bartee BK. Evaluation of new polytetrafluoroethylene-guided tissue regeneration membrane

in healing extraction sites. Compendium. 1998;19:1256–8. 1260, 1262–4.

27. Bartee BK. The use of high-density polytetrafluoroethylene membrane to treat osseous defects

clinical reports. Implant Dent. 1995;4:21–6.

28.Scantlebury TV. 1982–1992: a decade of technology development for guided tissue regeneration. J Periodontol. 1993;64:1129–37.

29.Leknes KN, Røynstrand IT, Selvig KA. Human gingival tissue reactions to silk and expanded

polytetrafluoroethylene sutures. J Periodontol. 2005;76(1):34–42.

30.Edlich RF, Panek PH, Rodeheaver GT, Turnbull VG, Kurtz LD, Edgerton MT.  Physical

and chemical configuration of sutures in the development of surgical infection. Ann Surg.

1973;177:679–88.

31.Lilly GE.  Reaction of oral tissues to suture materials. Oral Surg Oral Med Oral Pathol.

1968;26:128–33.

32.Lilly GE, Armstrong JH, Salem JE, Cutcher JL. Reaction of oral tissues to suture materials.

Oral Surg Oral Med Oral Pathol. 1968;26:592–9.

33.Burkhardt R, Preiss A, Joss A, Lang NP. Influence of suture tension to the tearing characteristics of the soft tissues: an in vitro experiment. Clin Oral Implants Res. 2008;19:314–9.

34.Selvig KA, Kersten B, Chamberlain A, Wikesjö UME, Nilveus R.  Regenerative surgery of

intrabony periodontal defects using e-PTFE barrier membranes. Scanning electron microscopic

evaluation of retrieved membranes versus clinical healing. J Periodontol. 1992;63:974–8.

35.Wilderman M, Wentz F, Orban B.  Histogenesis of repair after mucogingival surgery. J



Periodontol. 1960;31:283–99.

36.Nowzari H, Slots J. Microorganism in polytetrafluoroethylene barrier membranes for guided

tissue regeneration. J Clin Periodontol. 1994;21:203–10.

37.Tinti C, Parma-Benfenati S.  Vertical ridge augmentation: surgical protocol and retrospective evaluation of 48 consecutively inserted implants. Int J Periodontics Restorative Dent.

1998;18(5):434–43.

38.Hitti R, Kerns D.  Guided bone regeneration in the oral cavity: a review. Open Pathol J.

2011;5:33–45.

39.Pi-Anfruns J. Complications in implant dentistry. Alpha Omegan. 2014;107(1):8–12.



5



Soft Tissue Management for Implants

in the Aesthetic Zone

Perry R. Klokkevold



Abstract



While implant success depends on a multitude of factors, soft tissue management

is critical to the aesthetic success of anterior implant tooth replacement in the

partially edentulous patient. The peri-implant soft tissue appearance should emulate and match natural periodontal aesthetics. Ideally, peri-implant soft tissues

blend imperceptibly with and mimic the surrounding periodontal soft tissues of

the natural dentition. Achieving that goal requires an understanding of periodontal and peri-implant anatomy and an appreciation for factors that influence soft

tissue contours around teeth and dental implant restorations. In addition to mastering surgical objectives and techniques, clinicians must be able to evaluate and

accurately diagnose the existing periodontal condition.



5.1



Introduction



Soft tissue management is critical to the aesthetic success of anterior tooth replacement with implants in the partially edentulous patient. The peri-implant soft tissue

appearance should emulate and match the natural periodontal aesthetics. In the ideal

aesthetic outcome, peri-implant soft tissues will blend imperceptibly with and

mimic the surrounding periodontal soft tissues of the natural dentition. Achieving

that goal requires an understanding of periodontal and peri-implant anatomy and an

appreciation for factors that influence soft tissue contours around teeth and dental



P. R. Klokkevold

Section of Periodontics, University of California, Los Angeles, CA, USA

e-mail: pklokkevold@dentistry.ucla.edu

© Springer International Publishing AG, part of Springer Nature 2019

Todd R. Schoenbaum (ed.), Implants in the Aesthetic Zone,

https://doi.org/10.1007/978-3-319-72601-4_5



95



96



P. R. Klokkevold



implant restorations. And, in the case of deficient contours, it may require soft tissue

augmentation procedures to reconstruct or enhance missing structure and volume.

This chapter describes soft tissue aesthetics, soft tissue management, and surgical strategies to enhance the aesthetic predictability for implants in the partially

edentulous patient.



5.2



Ideal Soft Tissue Aesthetics



What is ideal periodontal (soft tissue) aesthetics? Certainly, the criteria for soft tissue aesthetics will vary from one individual to another. Each individual is unique.

Upon smiling, the amount of gingival display will range from very little or no visible soft tissues to an excessive amount of soft tissue exposure, sometimes referred

to as a “gummy smile,” and everything in between (Fig. 5.1). The amount of gingival display for a given individual will differ and will likely influence the degree of

his/her concern with soft tissue aesthetics. However, regardless of gingival display,

individual personal preference and aesthetic demands may vary from frank indifference to an obsessive attention to detail and a need for perfection, even when soft

tissues are not visible in their normal smile.

While some individuals will have little concern about aesthetics, most will be at

least moderately concerned. It is important to assess each individual’s aesthetic

desires and to determine whether their expectations are realistic relative to the limits

of their presenting circumstances. If not, and especially if the patient has truly unrealistic expectations, it is imperative to clearly discuss treatment options along with

anticipated outcomes and to reach an understanding about the goals and limitations

of treatment prior to initiating therapy.

In general, the ideal periodontal soft tissue aesthetics will consist of healthy,

coral pink soft tissues that circumscribe the crowns and fill the interproximal spaces.

The papillae will be peaked up to the contact point, and, with the exception of the

midline papilla, they will be balanced and symmetrical with the corresponding contralateral papilla and tightly adapted to the tooth surfaces. The gingival margins

follow the cementoenamel junction forming a smooth arch around each crown with

a zenith that is slightly distal to or coincident with the midline of each tooth. The

zenith or peak of the gingival margin typically aligns with the long axis of the tooth



a



b



c



Fig. 5.1 (a) Patient with low smile line. There is limited or no gingival display upon smiling. (b)

Patient with average smile line. There is a partial gingival display upon smiling. (c) Patient with

high smile line. There is significant gingival display upon smiling



5  Soft Tissue Management for Implants in the Aesthetic Zone



97



Fig. 5.2  Ideal periodontal aesthetics in a natural dentition without restoration or missing teeth.

Soft tissue contours are bilaterally symmetrical. Interproximal spaces are filled with papilla peaked

up to the contact point. The gingival margin is influenced by the axial inclination of each tooth; it

follows the cementoenamel junction with zenith located coincident or slightly distal to the midline

as depicted with a dotted line through the long axis of the tooth



and will be influenced by the position and prominence of the tooth within the alveolus. The gingival margin height of smaller teeth, such as the lateral incisors, will

often be 1–2 mm lower (more coronal) than the gingival margins of the adjacent,

larger teeth. The gingival margins of the centrals and canines will be fairly equivalent in height. Healthy periodontal tissues are firm, knife edged, and closely adherent to the tooth surfaces. As an example, Fig. 5.2 shows aesthetically ideal, healthy

periodontal soft tissues surrounding a natural dentition without restorations or missing teeth.



5.3



Soft Tissue Deficits with Dental Implants



The dimensions of periodontal tissues are greater with natural teeth present than

when missing or replaced with dental implants. Tooth loss whether caused by disease or trauma often results in loss of hard and soft tissue volume. Aesthetic tooth

replacement with dental implants is most challenging when there is a lack of tissue

volume to support and surround the implant restoration. State-of-the-art advances in

dental materials, digital technologies, laboratory techniques, and artistic skills have

made it possible to fabricate very realistic prosthetic tooth restorations that are

indistinguishable from natural teeth. Consequently, it is the lack of tissue volume

that presents the most significant challenge for the successful aesthetic replacement

of missing teeth with implants, especially in anterior partially edentulous patients.

First and foremost, there must be an adequate volume of the bone in the area to

support implant(s) in the proper prosthetically driven position. See Chap. 2 for

details of diagnostic imaging, implant planning, and implant simulation and

Chaps. 3, 4, 7 for details of bone augmentation/preservation procedures for situations when bone reconstruction is indicated. Adequate bone volume and proper

implant position are essential elements that must be present prior to considering the

nuances of achieving soft tissue aesthetics. Assuming an adequate bone volume and

appropriate implant position, soft tissue deficits may still present a challenge for

aesthetic tooth replacement. Common peri-implant soft tissue problems include

recession (Fig. 5.3) and deficient papillae (Fig. 5.4).



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