Wound Healing And Anatomical Considerations For Implants

Question 1

Who discovered that when pure titanium comes into direct contact with the living bone tissues, the two form a permanent adhesion (osseointegration)

Answer 1

Professor Per-Ingvar Branemark - father of modern day implantology

Question 2

Types of implant healing

Answer 2

Fiber integration
Fibo osseous integration
Osteo integration

Question 3

Fibro osseous integration

Answer 3

-Tissue to implant contact with dense collagenous tissue between the implant and bone
-initially good successor ate but extremely poor long term success
-failure by todays standards
-soft tissue contact with implant

Question 4

Osseointegration

Answer 4

Direct connection between living bone and load bearing endosseous implants at the light microscopic level

Question 5

Repair

Answer 5

Results in tissues that are structurally and functionally different form their pre injury sites

Question 6

Regeneration

Answer 6

Results in tissues that are structurally and functionally similar to their preinjured site

Question 7

GTR

Answer 7

Guided tissue regeneration
In periodontal defects include furcation of new bone, cementum, and PDL (around tooth)

Question 8

GBR

Answer 8

Guided bone generation
On bone

Question 9

Stages of bone healing

Answer 9

Phase 1= inflammatory phase
Phase 2= proliferation phase
Phase 3= maturation phase

Question 10

Phase 1- inflammatory phase Days

Answer 10

1-10

Question 11

Things that happen in phase 1 (inflammatory phase)

Answer 11

Platelet aggregation and activation
Clotting cascade activation
Nonspecific cellular inflammatory response
Specific inflammatory response
Macrophages mediated inflammation

Question 12

Phase II proliferative phase days

Answer 12

3-42

Question 13

What happens during phase II (proliferative phase)

Answer 13

Neovascularization on the clot
Differentiation, proliferation and activation of cells (fibroblasts —> osteoblasts, osteoclasts)
Production of immature connective tissue matrix (Granulation tissue)

Question 14

Phase III (maturation phase) days

Answer 14

After day 28

Question 15

What happens during the phase III (maturation)?

Answer 15

Remodeling of the immature connective tissue matrix with coupled resorption/depostion of bone
Physiologic bone resorption

Question 16

Bone modeling

Answer 16

When bone resorption and bone formation occur on separate surfaces
Formation and resorption are not coupled
Causes change in bone shape
Ex. Ortho forces

Question 17

Bone remodeling

Answer 17

Replacement of old tissue by new bone tissue
Formation and resorption are coupled at same site
No changes in shape
Normally: implant site healing

Question 18

Junctional epithelium

Answer 18

Attaches to implant surface by basal lamina and hemidesmosmes (same as teeth)

Question 19

Connective tissue attachment

Answer 19

Fibers parallel to implant surface
No direct attachment to implant surface
20nm amorphous glycoproteins layer between CT and implant

Question 20

Biological width

Answer 20

Peri implant biological width is similar to width around natural teeth and serves similar protective barrier functions
THE WIDTH IS LARGER THAN BIOLOGICAL WIDTH AROUND TEETH DUE TO LONGER JUNCTIONAL EPITHELIUM
Peri-implant CT fibers are generally parallel to the implant surface, tight adhesive attachment to the implant surface

Question 21

Why is it important to have maintenance of the soft tissue seal (junctional epithelium, CT)?

Answer 21

Prevent peri implant mucus it is and peri implantitis
Bacterial can pass through easier on an implant surface than on a tooth surface

Question 22

Marginal inflation —» ________ —-> per implant bone loss ——-> ________ —-> eventual implant loss

Answer 22

Apical spread ; peri implanttitis

Question 23

How is the tissue interface around the implant similar/different to tooth?

Answer 23

Has junctional epithelium and CT but no PDL
Weak attachment

Question 24

Does inflammation spread faster from soft tissue to implant or soft tissue or tooth?

Answer 24

SOFT TISSUE TO IMPLANT

Question 25

Peri implant sulcus

Answer 25

Microbes more pathogenic

Question 26

Factors that affect healing

Answer 26

Surgical technique Pt selection Oral hygiene Bone density Site selection

Question 27

Surgical technique

Answer 27

Frictional heat= temp threshold is 47 degrees C Greater = failure to achieve ossoeintegration = thermal injury Necrosis of bone

Question 28

How can you reduce heat

Answer 28

Gentle surgical technique, using sequential drills, use sharp drills, copious irrigation, use drills at recommended RPM

Question 29

Drilling sequence for osteotomy

Answer 29

Small to large

Question 30

Surgical technique two methods

Answer 30

Delicate soft tissue manipulation - maintain periosteal integrity and keratin end tissue and soft tissue biotype Periosteum - has blood vessels and local osteoblasts, important for bone healing

Question 31

Compression necrosis

Answer 31

Drilling into dense bone - compression of trabecular marrow space, lost blood supply, necrosis Dependent on - high insertion torque and high bone density type

Question 32

D1 bone density

Answer 32

Oak/maple wood

Question 33

D2 bone density

Answer 33

White pine or spruce wood

Question 34

D3 bone density

Answer 34

Balsa wood

Question 35

D4 bone density

Answer 35

Styrofoam

Question 36

Cortical bone density

Answer 36

Mandible > Maxilla

Question 37

Most dense

Answer 37

Mandibular anterior - less blood supply

Question 38

Least dense

Answer 38

Maxillary posterior Poor quality Soft bone but good blood supply

Question 39

Anterior vs posterior cancellous

Answer 39

Anterior = more Posterior= less

Question 40

Rough surface implants

Answer 40

Majority of implants today Increase roughness (surface treated, HA coats, plasma sprayed, sand blasted Increase SA, cellular attachment, primary stability, bone implant contact, success rate

Question 41

Machined surfaces

Answer 41

Smooth surface More bone loss than rough Decrease primary stability, less success, not used anymore

Question 42

Primary stability

Answer 42

At time of implant Decrease over time - 1st osteoclastic activity followed by osteoblastic response Osseointegration and healing occurs —> secondary stability (1-2 weeks) Most important during placement Micro movement of implant is the most common cause of implant failure (fibrous encapsulation)

Question 43

Mylohyoid ridge

Answer 43

Careful palpation —> concavity below the ridge anteriorly (sublingual fossa), posteriorly (submandibular fossa) Implants in post mandible high risk entering submandibular fossa ( highly vasuclarized) —> hemorrhage Can be life threatening

Question 44

Inferior alveolar nerve and mental foramen

Answer 44

Minimum 2 mm safe distance between implant and nerve Canal is surrounded by cortical bone —> however, tactile feedback cannot be relied on No substitutes for radiometrics, pre, intra, post operative PAs super important When in doubt CBCT

Question 45

Anterior loop of Ian

Answer 45

Majority of cases —> anterior loop is present Average loop dimensions: 3 mm PLACE IMPLANT AT LEAST 5 MM ANTERIOR TO THE LOOP - distance from implant surface to foramen not the osteotomy

Question 46

Mental foramen

Answer 46

Differs in horizontal and vertical plane 2mm distance between implant apex and foramen When in doubt, can surgically locate the foramen

Question 47

Lingual nerve

Answer 47

75% times 3 mm apical to the crest of the 3rd molar and 2mm from the lingual cortical plate in the flap Avoid lingual vertical incisions

Question 48

Nasopalatine foramen and canal

Answer 48

Contains nasopalatine nerve and sphenopalatine artery Could be at site of implant placement Complete degranulation of canal —> place implant —> graft the canal

Question 49

Greater palatine foramen and artery

Answer 49

Greater palatine artery foramen - near 3rd molar When harvesting tissue graft- careful reflection to prevent hemorrhage

Question 50

Maxillary sinus pneumatization

Answer 50

Need sinus lift either lateral wall or osteotomy mediated