Implant site prep Flashcards
How much hard tissue is needed
> 6mm
Types of hard tissue augmentation
– Particulate grafts – Block grafts – Membrane tenting – Sinus lift • Tissue Engineering – PDGF – BMP-2
Prereqs for bone formation
– adequate blood supply – space for new bone formation – exclusion of competing tissues
Challenges to
obtaining predictable
bone growth:
– rapid soft tissue
formation
– lack of space for
bone in-growth
Guided bone regeneration
• Procedures attempting to regenerate lost bone – Protection of bone regeneration against overgrowth by rapidly proliferating nonosteogenic tissues
Ideal membranes for GBR
• Biocompatible • Occlusive • Space-making • Capable of tissue integration • Clinically manageable
Barrier membranes for GBR
– nonresorbable (e-PTFE)
– resorbable (collagen, polymers)
Space-making materials for gbr
– autogenous/allogeneic/xenogeneic bone grafts
– alloplasts (synthetic grafts)
– tenting pins
– titanium reinforced membranes
Tenting and membrane
fixation pins:
– stainless steel
– titanium
– resorbable pins
Indications for GBR
Inadequate bone volume – unable to achieve primary implant stability – bone defects large / extended – implant cannot be placed in proper position – esthetic demands • Proximity to anatomic structures – mandibular nerve – maxillary sinus
Surgical Procedures for GBR
- Ridge Preservation
(extraction sites) - Ridge Augmentation
- Sinus Augmentation
Results of ext
– Loss of bone more buccal than lingual
– Horizontal loss may be up to 4.4 mm
– Vertical loss may be up to 1.2 mm
– Greatest changes occurring with in first 6 months
– Soft tissue changes may challenge our esthetics
Ridge Augmentation
– to develop new bone volume prior to implant
placement (staged therapy)
– to augment existing bone at time of implant
placement (simultaneous therapy)
– many principles similar to ridge preservation
Ridge Augmentation
– How long do I wait before placing implant?
• Minimum waiting time unknown
• Depends on material used to augment (block vs.
particulate graft)
• Recommend at 4 to 6 months (longer for particulate
allograft/ xenograft)
– Some prefer shorter waiting times
Autogenous Block Grafting
key points
– Need monocortical block only!
– Must have sufficient A-P dimension in symphysis
region
– Bi-cortical block may result in severe hemorrhage
• Bur can cut thru lingual periosteum into floor of mouth
• Can cause severe hematoma (airway obstruction)
Piezosurgery
• Precision osteotomies; 24-30k Hz
• Safer in proximity to soft tissues
– Surgical action of tip ceases when in contact with soft tissue
– Membrane perforation – most common complication
• Conventional – 20-30%
• Piezo – 5% (Vercellotti, et al., 2005)
• Split ridge applications for implant placement
Sinus Augmentation
– to develop new bone volume in the sinus prior to
implant placement (staged therapy)
– to augment existing bone in the sinus at time of
implant placement (simultaneous therapy)
Commonly Used Growth Factors
Platelet-rich plasma (PRP) Marx Enamel matrix derivatives (EMD) Emdogain® Platelet-derived growth factor (PDGF) Gem 21S® Bone morphogenic protein-2 (BMP-2) INFUSE®
BMP
-In vitro studies have shown that BMP causes the chemotactic
migration of bone-forming cells to the site of local
concentration.
-exposure to BMP causes the cell specific
proliferation of undifferentiated human mesenchymal stem
cells.
-Comprehensive analysis of osteogenic activity of 14 types of
BMPs. BMP 2, 6, and 9 play an important role in inducing
osteoblast differentiation of mesenchymal stem cells
How much bone at the max sinus floor to do osteotome v lateral windo
5-6mm for osteotome
other wise lat window.
