55. Soft tissue aesthetics and augmentation in implantology.

Question 1

Esthetic importance of tissue biotype in implantology

Answer 1

• Type 1 Implant Placement=>flapless surgery w/ immediate provisionalization=>
• Good esthetic outcome.
• Type 2 Implant Placement=>Preferred in esthetic zone=>
• Reduces facial soft tissue recession compared to Type 1

Question 2

Bone volume decrease over time after tooth extraction

Answer 2

• Bone Loss After Extraction=>25% in first year
• 40-60% over first three years

Question 3

Important modifiable factors to consider for ridge augmentation

Answer 3

• Promoting Primary Wound Closure=>
• Tension-free primary soft tissue closure
• Augmenting soft tissues prior to bone augmentation
• Enhancing Cell Proliferation and Differentiation=>
• Blood, oxygen, and nutrients to tissues=>
• Marrow excellent source of osteogenic cells
• Protecting Initial Wound Stability=>
• Titanium-reinforced membranes=>
• space maintenance and proliferation of bone-forming cells

Question 4

How alveolar crest defects classified according to Seibert

Answer 4

• Class 1 Defects: In horizontal dimension
• Class 2 Defects: In vertical dimension
• Class 3 Defects: Both in vertical and horizontal dimensions

Question 5

How fresh extraction socket defects classified according to Hämmerle and Jung

Answer 5

• Class 1=> socket w/ intact bone walls
• Class 2=>socket w/ marginal dehiscence/fenestration of buccal bone wall
• Class 3=>socket w/ large dehiscence of the buccal bone wall
• One-step GBR=>Indicated for Class 1 and 2 defects
• Delayed Approach=> Indicated for large Class 3 defects

Question 6

Guided Tissue Regeneration (GTR)

Answer 6

• Regenerating periodontal structures lost due to periodontal disease=>
• Barrier membranes direct growth of new bone and periodontal ligament=>
• On root surface previously exposed due to disease

Question 7

Materials used for barrier membranes in GTR

Answer 7

• Non-absorbable materials=>
• Polytetrafluoroethylene (PTFE)
• Expanded polytetrafluoroethylene (e-PTFE)=>
• Often reinforced w/ titanium
• Perforated titanium foil
• Bioabsorbable materials=>
• Natural materials: Collagen membranes from porcine or bovine origin
• Synthetic materials=> Polylactic acid, copolymers of polylactic acid, polyglycolic acid, PEG

Question 8

Requirements for barrier membrane materials in GTR

Answer 8

• Biocompatibility=>No adverse tissue reactions
• Barrier function=>allowing passage of desirable gases and nutrients
• Tissue integration=>Should permit tissue growth into, but not through, membrane
• Maintain space for tissue ingrowth
• Easy to trim and place

Question 9

Characteristics of non-absorbable membranes

Answer 9

• Do not provoke tissue reactions
• Second surgical procedure for removal
• Porous and non-porous options=>titanium foil w/ specific thickness and perforations

Question 10

Characteristics and complications of bioabsorbable membranes

Answer 10

• More compatible than non-absorbable membranes
• Avoid need for second surgery to remove membrane
• Complications=>early degradation, epithelial downgrowth, premature loss of material

Question 11

Synthetic bioabsorbable membranes

Answer 11

• Polylactate acid and its copolymers
• Polyglycolic acid and its copolymers
• Polyglactin (Vicryl)
• PEG

Question 12

Natural bioabsorbable membranes

Answer 12

• Porcine origin=>Jason membrane and Collprotect membrane
• Bovine origin=>Geistlich Bio-Gide®

Question 13

Types of bone replacement grafts used in GTR

Answer 13

• Autologous grafts (autografts)=>patient’s own body
• Isografts=>genetically identical species
• Allografts=>different individuals of same species
• Xenografts=>different species
• Synthetic grafts (alloplasts)=> synthetic materials
• Composite grafts=>combination of different graft materials

Question 14

Autografts

Answer 14

• Same individual
• Osteogenic (4 weeks) osteoconductive and osteoinducive (2-4weeks) potential
• Extraoral=>
• Iliac crest, tibia, fibula, ribs
• Intraoral=>
• Chin, exostoses, torus
• Ramus, tuberosity

Question 15

Isografts

Answer 15

• Genetically identical species

Question 16

Allografts

Answer 16

• Same species
• Osteoinductive potential
• DFDBA=>deminineralised freeze dried bone allograft
• FDBA=>freeze dried bone allograft
• Frozen

Question 17

Alloplasts

Answer 17

• Synthetic
• Osteoconductive
• Hydroxyapatite
• Calcium phosphate cements(CPC)
• Beta-tricalcium phosphate(TCP)
• Biphasic alloplastic materials
• Bioactive glasses
• Synthetic polymers

Question 18

Xenografts

Answer 18

• Different species
• Osteoconductive and osteoinducive potential
• Bovine derived
• Porcine derived
• Coralline calcium carbonate

Question 19

Potential of bone replacement grafts

Answer 19

• Osteogenesis=>new bone by cells in graft
• Osteoinduction=>new bone through differentiation of mesenchymal cells into osteoprogenitor cells
• Osteoconduction=>new bone by providing a scaffold for bone growth

Question 20

Biologically active regenerative materials used in GTR

Answer 20

• Platelet-derived growth factor (PDGF)
• Transforming growth factor ß1 (TGFß1)
• Fibroblast growth factor (FGF)
• Platelet-rich plasma (PRP)
• Enamel matrix derivative (EMD, such as
• Emdogain®)