Homeostasis of Alveolar Bone and other tissues supporting teeth and dental implants

Question 1

The jaw bone is comprised of the

Answer 1

alveolar process adn basal bone

Question 2

External plate of cortical bone:

Answer 2

Haversian bone and compact bone lamellae

Question 3

Inner socket wall of alveolar bone consists of

Answer 3

Alveolar bone proper (lamina dura which is compact bone)

Question 4

Cancellous bone

Answer 4

trabeculae between the two compact layers

Question 5

Describe the alveolar bone

Answer 5

Part of the jaw bone that forms and supports the tooth sockets.

Question 6

When does the alveoalr bone form?

Answer 6

When the tooth erupts

Question 7

Alveolar bone provides the osseous attachment to the

Answer 7

periodontal ligament

Question 8

What anatomical features determine the alveolar bone morphology?

Answer 8

• Alignment of the teeth
• proximity between teeth
• Root and trunk anatomy
• Root position within the alveolar process

Question 9

Anatomical factors that determine the alveolar bone morphology and are important in the pathogenesis of periodontal disease include

Answer 9

• Thickness and width of interdental bone
• Thickness of F/L alveolar plate
• Proximity between teeth
• Alignement of teeth
• Root and trunk anatomy
• Root position within the alveolar process
• Presence of fenestrations and dehiscences

Question 10

Vertical/angular bone defects do not form in

Answer 10

thin facial or lingual alveolar bone

Question 11

Alveolar bone gradually diminishes in size and may disappear completely after

Answer 11

the teeth are lost

Question 12

What is the periodontium?

Answer 12

Gingiva, cementum, PDL, alveolar bone

Question 13

The PDL is composed of

Answer 13

a complex vascular and highly cellular CT that surrounds the root and connects it to the inner wall of the alveolar bone

Question 14

How are the lamellae of the lamellated bone arranged?

Answer 14

Roughly parallel to the surface of the adjacent marrow spaces, others form Haversian systems

Question 15

Bundle bone is part of the alveolar bone proper to which the

Answer 15

principal fibers of the periodontal membrane are anchored

Question 16

Where do Sharpeys fibers insert?

Answer 16

Into cementum and bone

Question 17

Where is PDL space reduced?

Answer 17

around teeth that are not in function

Question 18

Where is the PDL space increased?

Answer 18

In teeth that have been subjected to hyperfunction

Question 19

PDL contains what receptors?

Answer 19

Ruffini nerve endings and nociceptors

Question 20

What are Ruffini nerve endings?

Answer 20

Primary mechanoreceptor

Question 21

Peri-implant mucosa has _______ permeability

Answer 21

low

Question 22

How are intercellular spaces sealed in the sulcular epi around implants?

Answer 22

desmosomes

Question 23

Cells of the junctional epi attachment adjacent to dental implants attach to basal lamina with

Answer 23

hemidesmosomes

Question 24

Peri-implant CT morphology is similar to that of the natural dentition, except that it lacks what?

Answer 24

-PDL
- Cementum
- Inserting fibers

Question 25

How do the orientation of CT fibers adjacent to an implant differ from CT fibers adjacent to teeth?

Answer 25

- Oriented perpendicularand run parallel to implant - Not embedded in implant surface - Some fibers have cuff like orientation to create seal

Question 26

Xone of supracrestal CT has an important function in what for implant-CT fiber interface?

Answer 26

Maintencance of a stable soft tissue implant interface and as a seal to the outside environment

Question 27

Blood supply in the CT cuff surrounding the implant/abutment is ____ than in the gingival complex around teeth

Answer 27

less

Question 28

What are the overall functions of the PDL?

Answer 28

- Physical - Fromative - Remodeling - Sensory

Question 29

What are the phases of wound healing following surgical periodontal therapy?

Answer 29

- Hemostasis - Inflammation - Proliferation - Maturation (remodeling)

Question 30

Descrie overall bone remodeling

Answer 30

- Bone resorption - Apposition of new bone - Coordinated, continuous process

Question 31

Why is bone remodeling important?

Answer 31

- Growth - Ca ion balance - Eruption and migration of teeth - Orthodontic tooth movement - Wound healing

Question 32

What are the stages of wound healing and osseointegration?

Answer 32

1. Hemostasis and formation of a coagulum 2. Granulation tissue formation 3. Bone formation 4. Bone remodeling

Question 33

What happens at Day 1 wound healing/osseointegration?

Answer 33

Coagulum formation

Question 34

What happens at Day 4 wound healing/osseointegration?

Answer 34

Coagulum replaced wtih granulation tissue that contains inflammatory cells, numerous mesenchymal cells and newly formed vessels

Question 35

What happens at 1 week wound healing/osseointegration?

Answer 35

Fingerlike projections of woven bone occur around vascular structres in the center of the chambers and also in direct contact with small areas of the implant

Question 36

What happens at week 2 of wound healing/osseointegration?

Answer 36

- Woven bone is deposited on the bony wall of the tissue chamber and on the implant surface - Scaffold of tiny trabeculae of woven bone connects the old bone and implant surface

Question 37

Why would there be a delay of new bone formation when compact old bone is in contact witht he implant surface?

Answer 37

Old bone needs to be resorbed first (remodeling)

Question 38

What happens at 4 weeks wound healing/osseointegration?

Answer 38

- Chambers filled with woven bone extending from the old bone to reach surface of titanium - Volumedensity of scaffold is increased by formation of new trabeculae and by deposition of more mature parallel-fibered bone onto primary scaffold

Question 39

What happens at 6-12 weeks wound healing/osseointegration?

Answer 39

- Bone remodeling (primary replaced with secondary osteons, woven bone replaced with lamellar and marrow) - Bone to implant contact is establsihed

Question 40

Describe bone remodeling

Answer 40

- Bone resorption followed by bone apposition - COntinuous

Question 41

If amount of newly formed bone is less than the amount of resorbed bone, then

Answer 41

- Continuous net loss of bone to implant contact - Osteointegration is comrpomised - Implant may fail

Question 42

What are factors that influence osseointegration?

Answer 42

- Initial mechanical implant stability is a prerequisite for osseointegration - Initial stability is achieved by mechanical facros

Question 43

What are the factors that determine the magnitude of primary implant stability?

Answer 43

1. % of bone to implant contact 2. Macro design of implant in relation ot implant site prep 3. Vertical position of implant relative to bone crest 4. Surface morphology or roughness of implant 5. Local bone quality (compact bone contributes more than trabecular to primary stability)

Question 44

How is secondary stability of dental implants?

Answer 44

By apposition of new bone onto the implant surface (biological)

Question 45

Secondary stability: New bone apposition begins earlier in regions of

Answer 45

trabecular bone than in compact bone

Question 46

Does primary stability increase or decrease over time?

Answer 46

Decreases

Question 47

Does secondary stability increase or decrease over time?

Answer 47

Increase

Question 48

What accounts for the total implant stability?

Answer 48

Sum of primary stability and secondary stability

Question 49

Transient decrease in implant stability occurs how many weeks after implant placement?

Answer 49

3-4 weeks

Question 50

How can a higher total implant stability and less pronounced subsequent stability dip be achieved?

Answer 50

By having both cortical and trabecular bone surrounding the freshly placed implant

Question 51

What are key factors for successful alveolar bone regeneration?

Answer 51

- Elimination of infection - Hemostasis and clot stabilization - Space provision - Wound closure - Surgical technique - Innate wound healing potential (avail of cell types, cell signals for recruitment and stim of the progenitor cells)