Goodacre Crown Preps

Question 1

Total occlusal convergence

Answer 1

10 to 20º

Question 2

3 mm for anteriors/PM’s and 4 mm for molar’s references what measurement?

Answer 2

Incisocervical and occlusocervical measurements for resistance

Question 3

0.4 mm references what measurement?

Answer 3

Occlusocervical to faciolingual ratio

Question 4

Circumferential morphology should resemble what?

Answer 4

Natural tooth shape (preservation of shape). Rhomboid for max molar, rectangle for mand molar, ovals for anteriors and premolars

Question 5

Wound Healing

- Hemostasis (within minutes to hours)

Answer 5

Platelets accumulate for a blood clot and trigger the formation of fibrin matrix

Question 6

Wound Healing

- Inflammatory (24 hours to first week)

Answer 6

Granulation tissue forms and angiogenesis and epithelization begins.

Vasodilation occurs, trigger macrophages and PMLN leukocytes to arrive.

Bone morphogenic proteins and growth/differentiation factors are released. Collagen is deposited and early bond formation occurs.

Question 7

Wound Healing

- Proliferation (days to weeks)

Answer 7

Mesenchymal cells arrive and differentiate into osteoblasts. Osteoclasts and osteoblasts to begin distance and contact osteogenesis

• Completion of epithelization around three weeks and formation of woven bone

Question 8

Wound Healing

- Remodeling (3 months)

Answer 8

Osteoblasts/osteoclasts remodel woven bone into lamellar bone

Question 9

Featherstone

- Most common complications for FPD’s

Answer 9

Goodacre review - Caries was most common complication due to marginal gaps and difficult access to clean

Question 10

Featherstone - RPD’s

Answer 10

Increased caries and plaque for abutment teeth

Question 11

Fluoride mechanism in managing caries

Answer 11

1. Inhibiting demineralization
2. Enhancing remineralization
3. At high levels, inhibiting metabolism of bacteria

Question 12

Factors potentiating caries? (7)

Answer 12

1. Acidogenic bacteria
2. Reduced salivary function
3. Restorations harboring plaque
4. Frequent consumption of carbohydrates reducing pH
5. Decreased compliance with oral hygiene
6. Root exposure
7. Wearing FPD or RPD.

Question 13

Protective factors for caries (4)

Answer 13

1. Saliva
2. Salivary flow rate
3. Antibacterials
4. Other factors that raise pH and improve potential for remineralization

Question 14

Toothpaste fluoride levels

• OTC and prescription?
• Varnish? What percent decrease risk in caries? How often to apply?

Answer 14

1000 ppm - reduces caries by 20 to 35%

5000 ppm

12000 ppm - 30% reduction - 3 times a year

Question 15

Chlorhexidine - mechanism

Answer 15

Strong base with cationic properties. The molecules bind to negatively charged bacteria cell walls and weaken bacteria over time

Question 16

Interaction between CHX and fluoride?

Answer 16

Should be delivered 1 hour apart as fluoride ion is negative and CHX ion is positive.

Question 17

Amorphous calcium phosphate - MI Paste - mechanism

Answer 17

Remineralizes tooth structure with high concentrations of calcium and phosphate

Question 18

Normal salivary rate?

- What is in saliva? (5)

Answer 18

1.5 L/day

1. Water
2. Buffering agents
3. Enzymes
4. Remineralization agents (calcum, phosphate, fluoride)
5. Fungicidal and antibacterial agents