Carranza chapter 72

1. LOCALIZED BONE
AUGMENTATION AND IMPLANT
SITE DEVELOPMENT
Chapter 72

2. Localized bone augmentation and
implant site development
• Guided bone regeneration
• Barrier membranes
• Bone graft materials
• Autogenous bone
• Localized ridge augmentation
• Flap management
• Horizontal bone augmentation
• Simultaneous implant placement
• Complications

3. Localized bone augmentation and
implant site development
• Alveolar ridge preservation/management of
extractions
• Delayed implant placement
• Staged implant placement
• Delayed versus staged technique
• Immediate implant placement

4. • Standard implant surgery
• Adequate bone volume and quality
• Adequate remodeling and maturation of bone
• Surgical bone augmentation
• To correct or to prevent alveolar ridge deficiency
Localized bone augmentation and
implant site development

5. • Guided tissue regeneration(GTR) : Specific cells
contribute to the formation of specific tissue
• Exclusion of the faster-growing epithelium and
CNT from a periodontal wound.
• Osteoblasts, cementoblasts and periodontal
ligament cells -> regenerate a new periodontal
attachment
Guided tissue regeneration(GTR)

6. Guided bone regeneration (GBR)
• In membrane-protected defects, bone
regeneration was initiated by formation of
woven bone along new blood vasculature at
the periphery of the defect
• Bone was being isolated from the surrounding
soft tissue : GBR
Schenk et al. Int J Oral Maxillofac Implants 1994

7. Guided bone regeneration (GBR)
• Bone : unique tissue that has capacity to
regenerate itself completely
• New bone formation : adequate blood supply

8. • Biocompatible materials
• Protect blood clot
• Prevent soft tissue cells from migrating into
bone defect
• Resorbable / Nonresorbable materials
GBR: Barrier membranes

9. • Ideal properties
1. Biocompatibility
2. Space maintainance
3. Cell occlusiveness
4. Good handling properties
5. Resorbability or ease of removal(Nonresorbable)
GBR: Barrier membranes

10. • Nonresorbable barrier membranes
• Latex, Teflon (ePTFE, Gore-tex)
• Variety of shapes and sizes
• Combined with bone graft material for space
maintainer
GBR: Barrier membranes
Case by Prof. Massimo Simion & Dr. Isabella Rocchietta, Italy/UK

11. • Nonresorbable barrier membranes
• Require second surgery to remove (6-12 months)
• Stiffer membranes (Titanium-reinforced) :
promote significant amount of new bone
GBR: Barrier membranes

12. • Nonresorbable barrier membranes
• Advantages
• Maintain separation of tissue over an extended
time
• Disadvantages
• If it becomes exposed, it will not heal
• Membrane exposure -> infection
GBR: Barrier membranes

13. • Resorbable barrier membranes
• NO second surgery
• Polylactide/ polyglycolide(PLA/PGA), Collagen-
based
• Support growth of new bone when combine with
bone graft to resist collapse
• Reduce bone resorption
GBR: Barrier membranes

14. • Resorbable barrier membranes
• Advantages
• No second surgery
• Less likely to become expose
• Less problematic if they do become exposed
• Disadvantages
• May degrade before bone formation complete
• The degradation process may produce inflammation
• Lack of stiffness -> tenting screws, plates
GBR: Barrier membranes

15. GBR: Bone graft materials
• To facilitate bone formation within a given
space by occupying and allowing subsequent
bone growth
• Biologic mechanism
• Osteoconduction
• Osteoinduction
• Osteogenesis

16. • Osteoconduction
• Materials serve as scaffold for bone growth
• Osteoblasts from the margins of defect -> bone
formation
Osteoconduction

17. Osteoinduction
• Osteoinduction
• Stimulate osteoprogenitor cells from the defect to
differentiate into osteoblasts -> forming new bone
• The induction of bone-forming process by
activating bone-forming cells through mediators
• Bone morphogenic proteins (BMP)

18. Osteogenesis
• Osteogenesis
• Living osteoblasts : part of the bone graft as in
autogenous bone graft
• Osteoblasts form new centers of ossification
within the graft

19. GBR: Bone graft materials

20. Autogenous bone
• Bone graft materials of choice:
osteoconductive, osteoinductive, osteogenic
• No risk of graft rejection
• Edentulous space, maxillary tuberosity,
mandibular ramus, mandibular symphysis and
healing extraction socket (6-12 weeks)

21. Autogenous bone
• Disadvantages : increase risk of morbidity
• Mandibular symphysis : postoperative bleeding,
bruising, wound dehiscence, damage lower
incisors and injury to nerves
• Retrospective analysis of 48 chin graft : 5-mm
margin of safety between graft harvest and vital
structures
Hunt et al. Int J Periodontics Restorative Dent 1999

22. • Basic principles to minimize the
risk of postoperative morbidity
• Radiographic evaluation
• Locate mental nerve and foramen
• Do not elevate or reflect muscle
attachment beyond the inferior
border mandible
• 5 mm safety zone : tooth apices,
inferior border of mandible,
mental foramen
Autogenous bone

23. • Basic principles to minimize the risk of
postoperative morbidity
• Do no harvest deeper than 6mm
• Suture the wound in layers
• Prevent overheating : 47 °C can cause bone
necrosis -> proper irrigation / Piezoelectric bone
surgery
Autogenous bone

24. Localized bone augmentation and
implant site development
• Guided bone regeneration
• Barrier membranes
• Bone graft materials
• Autogenous bone
• Localized ridge augmentation
• Flap management
• Horizontal bone augmentation
• Simultaneous implant placement
• Complications

25. Localized ridge augmentation
• Size and morphology of defects : horizontal/
vertical
• Combine with barrier membrane
• To achieve good results
• Blood supply
• Stable and protect space for bone growth
• Tension-free flap wound closure

26. Flap management
• Incisions, reflection, and manipulation should
be designed to
• Preserve vascularity of the flap
• Minimize tissue injury
• Remote incision : wound opening is positioned
away from the graft.

27. Flap management
• Periosteal releasing incision/ Coronal
advancement of the flap + Crestal incision
• To achieve tension-free flap closure
• Suture removal 10-14 days
• No prosthesis inserted for 2-3 weeks

28. • General concepts for flap management
• Make incision remote to the placement of barrier
membrane
• Elevate full thickness flap 5mm beyond the edge of bone
defect
• Vertical releasing should be minimize
• Tension-free suture : Periosteal releasing incision
Flap management

29. • General concepts for flap management
• Prosthesis should not be inserted for 2 weeks
• Mattress sutures to approximate connective tissue
• Interupted sutures to adapt wound closure
Flap management

30. Horizontal bone augmentation
• Dehiscence / fenestration of implant surface
• Maxillary tuberosity graft -> increased ridge
width but 50% resorption
• Block graft from retromolar/ symphysis show
no clinical sign of resorption
Ten Bruggenkate et al. Int J Maxillofac Surg 1992
Buser et al. J Oral Maxillofac Surg 1996

31. Horizontal bone augmentation
• FDBA + Membrane -> increased amount of
new bone and no remaining allograft
materials in 9 months
• Particulate bone graft
• Monobloc bone graft
Doblin et al. Int J Periodontics Restorative Dent 1996
Nevin, Mellonig. Int J Periodontics Restorative Dent 1994

32. • Particulate bone graft
• Smaller pieces  rapid ingrowth of blood vessels
•  large osteoconduction surface
• more expose osteoinductive growth factors
• Lack of rigid
• Easily displaced
Horizontal bone augmentation

33. • Particulate bone graft
• Smaller pieces  rapid ingrowth of blood vessels
•  large osteoconduction surface
• more expose osteoinductive growth factors
• Lack of rigid
• Easily displaced
Horizontal bone augmentation

34. • Particulate bone graft : indication
• Defect with multiple osseous wall that will contain
the graft
• Dehiscence or fenestration defect
• Bone graft and barrier membrane
combination when bone defect does not
containable
Horizontal bone augmentation

36. Monocortical block graft
• Harvest from the remote site : symphysis,
ramus, iliac crest, tibia
• With/without barrier membrane
• Screws or plate remove after an adequate of
time (6 months)
• Disadvantages: biologic limitation of
revascularizing large block

37. Monocortical block graft
6 months

38. Monocortical block graft

39. Simultaneous implant placement
• In selected case, bone augmentation can be
placed simultaneously with implant
placement
• good primary stability in native bone

40. Simultaneous implant placement
Fenestration defects Dehiscence defects

41. • Barrier membrane VS periosteal flap coverage
of expose implant surface
• Membrane was far superior with regard to
bone file
• 66% of treated with membrane resulted in 95-
100% elimination of dehiscence
Simultaneous implant placement
Dahlin et al. Clin Oral Implants Res 1991
Palmer et al. Clin Oral Implants Res 1994

42. • 55 Branemark implant(machine-surface,
external hex) treated by ePTFE membrane
alone -> 82% bone fill
-> Cumulative survival rate 84.7%(Max),
95%(Mand)
Simultaneous implant placement
Dahlin et al. Int J Oral Maxillofac Implants 1995

43. • The use of graft materials in conjunction with
membrane treatment, especially FDBA+GBR
• Success rate of 96.8% (bone fill >90% of
dehiscence)
Simultaneous implant placement
Rominger et al. J Oral Maxillofac Surg 1994

44. Complications
• Bleeding
• Postoperative infection
• Bone fracture
• Nerve dysfunction
• Perforation of the
mucosa
• Sinusitis
• Pain
• Decubital ulcers
• Wound dehiscence
• Loss of portion of bone
graft

45. • The amount of new bone formation ->
• The length of membrane healing
• Size of the defect
• Bone regeneration depend on anatomy of
bone defect at the time of implant placement
Complications

46. Localized bone augmentation and
implant site development
• Alveolar ridge preservation/management of
extractions
• Delayed implant placement
• Staged implant placement
• Delayed versus staged technique
• Immediate implant placement

47. Alveolar ridge preservation
• Tooth extraction -> alveolar ridge resorption
• Preservation of bone volume -> Goal
• First 6- 24 months : most bone loss
• Barrier membrane enhance predictability of
bone fill compared with mucoperiosteal flap
alone

48. • Timing of implant placement depend on
• Quantity, quality and support of existing bone
• Agreement of clinician and patient
• Immediate : implant place at the time of extraction
• Delayed : implant place approximately 2 months after
extraction
• Staged : implant placement allow for substantial bone
healing (4-6 months)
Alveolar ridge preservation

49. • Tooth extraction : atraumatic surgical
technique, avoid bucco-lingual forces
• Remove soft tissue from extraction socket
• Evaluate bone level and socket anatomy
• Whether to bone-graft the site, when to place
the implant
Alveolar ridge preservation

50. Delayed implant placement
• Allow time for soft tissue healing to close the
wound
• Facilitate more osteogenesis because bone
formation is active within the first few months
• Resolution of infection

51. Staged implant placement
• Allow adequate time for osseous healing :
complete hard and soft tissue healing
• Implant place into healed bone sites
• Adequate coverage by hard and soft tissues
• Disadvantage : require the time for bone
healing

52. Delayed VS staged technique
• When to place the implant : quantity and
location of bone surrounding the tooth
bone sounding
• If little or no bone exists -> require bone
augmentation

53. Immediate implant placementc
• Reduce healing time
• Bone-to-implant healing begins immediately
with extraction site healing
• Disadvantages : need for subsequent
mucogingival surgery to correct soft tissue

54. • Implant may be placed in extraction socket
along with bone augmentation without flap
advancement : One-stage surgery
• One-stage approach with immediate implant
placement and provisionalization
Best way to manage hard and soft tissue
Immediate implant placementc

55. Conclusions
• Localized bone augmentation allow clinicians
to reconstruct horizontal alveolar ridge
defeciencies
• Implant can be placed simultaneously with the
augmentation
• Bone augmentation can be used to preserve
alveolar dimension following tooth extraction