Unit 15 - Local and Contributing Factors

Question 1

Does local contributing factors initiate periodontal disease?

Answer 1

No

Question 2

What is a disease site?

Answer 2

Indivudal tooth or specific surfaces of a tooth that are experiencing periodontal disease

Question 3

What is the composition of calculus?

Answer 3

70-90% inorganic
Primarily calcium phosphate with small portions of calcium carbonate and magnesium phosphate

10-30% organic
Includes materials from biofilm, dead epithelial cells, dead white blood cells
May also include living bacteria within calculus deposits

Question 4

Newly formed calculus deposit is called

Answer 4

Brushite

Question 5

Mature but less than 6 month old calculus is primarily

Answer 5

Octocaclium phosphate

Question 6

Calculus older than 6 months is primarily

Answer 6

Hydroxyapetite

Question 7

The shape of subgingival calculus is usually

Answer 7

Flattened

Question 8

What are the three modes of calculus attachement to the tooth surface?

Answer 8

Attachment to the pellicle
Attachment to the tooth irregularities
Attachment by direct contact to the tooth

Question 9

What is the pellicle?

Answer 9

A thin, bacteria free membrane that forms on the surface of the tooth during late stages of eruption

Question 10

What is the most common means of attachement for calculus to the enamel surfaces?

Answer 10

Attachment to the pellicle

Question 11

Why are calculus deposits attached to the pellicle removed easily?

Answer 11

Because attachment is on the surface of the pellicle, not looked to the tooth

Question 12

Where does calculus attach when classified as attachement to irregularities in the tooth surface?

Answer 12

Cracks in the tooth
Tiny openings in from the PDL detachment
Grooves in the cementum from over-instrumentation

Question 13

Why is attachment to irregularities in the tooth surface calculus difficult to remove?

Answer 13

Because deposits lie sheltered in tooth defects

Question 14

How does calculus attach to the tooth surface?

Answer 14

The matrix of calculus deposit may interlock with inorganic crystals of the tooth

Question 15

Why is calculus attached to the tooth surfae difficult to remove?

Answer 15

Deposits are firmly interlocked in the tooth

Question 16

What are the surface features of a tooth that may cause tooth morphology related increased plaque retention?

Answer 16

Tooth grooves or concavities
Cervical enamel projections and enamel pearls
Malocclusion
Dental caries
Orthodontic appliances

Question 17

What is a developmental groove on the palatal surface of a tooth called?

Answer 17

Palatogingival groove

Question 18

Some dental treatments may contribute to oral disease known as iatrogenic factor. Some examples are:

Answer 18

Overhanging margin
Open margin
Open contact
Poorly contoured crown
Orthodontic appliances
Poorly designed dental prosthesis

Question 19

If a crown margin is closer than 2mm to the alveolar crest it can result in

Answer 19

Bone resorption

Question 20

What are factors / causes of direct damage to the periodontium?

Answer 20

Food impaction
Improper use of plaque control aids
Tongue thrusting
Mouth breathing
Traumatic toothbrushing
Oral jewelry and body piercings
Trauma from occlusal forces
Parafunctional occlusal forces

Question 21

Signs of trauma from occlusion

Answer 21

Tooth mobility
Sensitivity to pressure
Migration of teeth
Enlarged, funnel-shaped PDL space
Alveolar bone resorption

Question 22

What is secondary occlusal trauma?

Answer 22

Injury to the periodontium from normal occlusal forces applied to a periodontium previously damaged by periodontitis