D1 - Operative Exam #4

Front 1

Class II caries: Anatomically the caries initiates in the...

Back 1

enamel apical to the proximal contact.

It extends as a cone to the DEJ; commonly described as two cones (or triangles) tip to base

Front 2

Black’s Principles of Cavity Preparation

Back 2

1. Outline form
2. Retention form
3. Resistance form
4. Convenience form
5. Removal of carious dentin
6. Finishing of the walls
7. Toilet of the cavity

Front 3

In a Class II prep, the pulpal and gingival walls are ________ to the long axis of the tooth.

Back 3

perpendicular

Front 4

Axial wall must be at least __ mm for premolars and __ mm for molars.

Back 4

1.2

1.5

Front 5

True/False?
For a class II prep., occlusal and proximal boxes must have independent retention

Back 5

True

Front 6

For a Class II prep: the “reverse, or “S” shaped”, curve” on the buccal serves what purposes?

Back 6

1. It preserves the mesiobuccal cusp ridge

2. Extends the wall into the buccal embrasure space

3. Leaves the enamel wall parallel to the enamel rods

Front 7

the enamel rods on the gingival wall are inclined...

Back 7

gingivally.

Front 8

The ideal gingival extension for a proximal box is how far below the contact area?

Back 8

0.5mm

Front 9

What Classes of Cavity Preparations Need Matrices?

Back 9

ALL CLASSES


Class I- e.g., OB or OL preparation
Class II- any proximal wall
Class III- any proximal wall
Class IV- proximal wall
Class V- when preparation extends past line angles into proximal area
Class IV- preparation extends including facial or lingual

Front 10

Function of wedges during tooth preparation

Back 10

Protects adjacent tooth during preparation from being hit by bur

Protects interseptal dental dam from tearing

Protects dental papilla from laceration

Front 11

Wedges are usually placed from...

Back 11

lingual to fill the larger gingival embrasure

Front 12

Thickness of Tofflemire Matrix bands

Back 12

Regular = 0.002” (0.05 mm)

Thin = 0.0015” (0.038 mm)

Extra thin = 0.001” (0.025 mm) usually used for composite restorations

Front 13

Matrix is placed so that __ mm extends apical to gingival margin, __ mm extends occlusal to marginal ridge

Back 13

1; 2

Front 14

Mylar matrices are used only for...

Back 14

composite resin materials

Front 15

Classes of amalgams that always need matrices

Back 15

Class II
Class III
Class IV

Front 16

Root caries are typically found on what surfaces?

Back 16

facial and lingual

Front 17

pH needed for demineralization of root surface

Back 17

pH 6.2-6.7

Front 18

The population typically affected
by root caries

Back 18

Elderly patients
Patients with poor oral hygiene
Patients with reduced salivary flow

Front 19

The prevalence of root caries in the elderly population

Back 19

65-74 years: 47%

>75 years: 55%

Front 20

The prevalence of gingival recession of 1 mm or more in patients 65 or older

Back 20

86.5 %

Front 21

Xerostomia

Back 21

Oral dryness and reduced salivary flow

Salivary flow will be reduced by 50% before the patient becomes noticeably symptomatic


less minerals and fluoride to remineralize the hard tissue
There is less ability to clear debris off the teeth and thus there is bacterial overgrowth

Front 22

Minimal depth of a class V preparation

Back 22

1 mm

Front 23

Class V prep: mesial and distal should be...

Back 23

divergent

Front 24

Glass Ionomer Cements

Back 24

Less esthetic than composite
Has a chemical bound to the tooth structure
Will adhere in conditions that are not completely dry
Releases Fluoride
Some are self curing agents

Front 25

Compomers

Back 25

Composite and Glass ionomers

Superior to Glass ionomers in tensile strength, flexural strength and wear resistance

They are bonded to teeth like composites, therefore the area must be dry

There is less Fluoride release than with RM-GIC

More esthetic than glass ionomers, but less than composites

Front 26

Diagnosis Frequently Associated with Xerostomia

Back 26

 Medication side effects
 Autoimmune Disorders
 Parkinson’s Disease
 Psychological Disorders
 Radiation of Salivary Glands
 Diabetes
 Sjögren’s Syndrome
 Dehydration

Front 27

Technology for enhanced caries detection

Back 27

Fiber optic transillumination
Magnification
Digital radiographic assessment
Light emitting caries detection devices

Front 28

Sensitivity

Back 28

The ability to detect disease when it is truly present.

Front 29

longevity of posterior composite and amalgam restorations

Back 29

Composite resin :
91.7% at 5 years
82.2% at 10 years

Amalgam:
89.6% at 5 years
79.2% at 10 years

Front 30

What is a clinical defect requiring restoration replacement?

Back 30

Restorative material partially/completely lost (fracture of restoration)
Fracture of surrounding tooth structure
Recurrent caries at a margin
Poor esthetics
Loss of occlusal function

Front 31

What does “conservative dentistry” mean?

Back 31

Minimize restoration failure “repeat restorative cycle”

Retention by adhesion and/or mechanical means

“Lesion-focused” preparation designs

Front 32

Conservative alternatives to Class I preparation:

Back 32

Fissure sealant
Sealant with Fissurotomy/Fissuroplasty
Preventive Resin Restoration

Front 33

Disadvantages of Preventive Resin Restoration

Back 33

Same concerns as sealants- loss rate of 5-10% per year

Front 34

Laser Cavity Preparation

Back 34

• Advantages:
– No anesthesia usually required
– Absence of vibration and sound of air turbine
– Laser micro-etches dentin and enamel improving micro-mechanical retention


• Disadvantages:
– Lack of tactile sense when cutting
– Requires open cavitated lesions for
maximum efficiency
– Restricted to adhesive materials due to the inability to prepare fine retentive features such as slots, grooves
– Cost of initial purchase

Front 35

accessory retention for amalgam restorations

Back 35

pins (placed into the dentin)

posts (within root canals after endodontic treatment)

slots (within tooth)

channels (within tooth)

grooves (placed within cavity walls)

Front 36

True/False?
amalgam is reinforced by pins

Back 36

False
Pins only RETAIN the amalgam

Front 37

Pin must be in dentin
Surrounded by at least
__ mm of dentin

Back 37

0.5

Front 38

If pin drill breaks in channel...

Back 38

Leave the drill bit broken in channel.

Find a new site to place a new channel approximately 0.5-1 mm away from where the pin drill broke.

Front 39

Copper tube circumferential matrix (no retainer)

Back 39

Sometimes only choice for matrix when many walls of tooth are missing

Difficult to fit and stabilize

Difficult to attain proximal contact due to the thickness of the band

Front 40

Crown preparations must have a minimum of __ mm of occlusal clearance.

Back 40

1.5

Front 41

For threaded pins: maximum retention is obtained when the pin extends
__ mm into dentin and __ mm into the amalgam.

Back 41

2; 2

Front 42

Retentiveness of pins:

Back 42

Self-threading pins are the most retentive.

Friction lock are intermediate

Cemented pins the least retentive.

Front 43

Pros/Cons of pins for retaining amalgam

Back 43

Advantages. Provide resistance to displacement by lateral (non-axial) forces. Axial forces are parallel to the long axis of the tooth.

Disadvantages: Pins are prone to create microfractures in dentin. The larger the pin the greater the likelihood that microfractures will occur.

Front 44

deep cavity depth

Back 44

depth of preparation with less than 1.0 mm of remaining dentin over pulp

Front 45

pulpal pain due to stimuli

Back 45

- not an inflammatory response
- likely due to the hydrodynamic theory
- stimulus causes rapid fluid flow through tubules, nerve endings deformed- interpreted as pain
- gap at tooth-restorative interface: the restoration is not well sealed

Front 46

base thickness to prevent thermal transfer should be no thicker than __ mm (thicker bases may weaken restoration)

Back 46

0.5-0.75

Front 47

cavity sealers:

Back 47

protective coating on the cavity walls creating a barrier to leakage


- varnish (Barrier)
- resin bonding systems (Scotchbond MP and OptiBond Solo)

Front 48

cavity liners:

Back 48

cement or resin coating of minimal thickness (less than 0.5mm) placed as a barrier to bacterial or to provide a therapeutic effect (pulpal sedative or antimicrobial effect). Applied to cavity walls adjacent to pulp.

- Calcium hydoxide = Dycal
- glass ionomer = VitreBond

Front 49

cavity bases:

Back 49

placed to replace missing dentin, placed in thickness of 0.5 - 1 mm; used to block out undercuts in cavity preparations for indirect restorations

glass ionomers = VitreBond, Fuji IX

Front 50

calcium hydroxide (Dycal)

Back 50

- Cavity liner
- Ca(OH) used to assist in formation of reparative dentin by its antibacterial effect
- best used for direct pulp cap
- use only small amount

Front 51

glass ionomer (Vitrebond)

Back 51

- cavity liner
- chemical bond - fluoride release
- chemically compatible with composite resins
- seals dentin
- generally not used for pulpal protection
- primary use in the past as dentin replacement to decrease bulk of restorative material
- primary use to block out undercuts in cavity preparations for indirect restorations (crowns, inlays, onlays)

Front 52

material of choice for cavity bases

Back 52

glass ionomer (Vitrebond)

Front 53

liners should be applied with a minimal thickness of less than __ mm

Back 53

0.5

Front 54

calcium hydroxide (Dycal) should be placed only...

Back 54

where needed adjacent to pulp

Front 55

Base/Liner recommendations for amalgam/composite:

Back 55

1. Shallow cavity: Sealer -> Amalgam/composite

2. Moderate cavity: Glass ionomer -> sealer -> amalgam/composite

3. Deep cavity: calcium hydroxide -> glass ionomer -> sealer -> amalgam/composite

Front 56

materials for use with amalgam

Back 56

1. cavity sealer
- varnish (Barrier)
- resin adhesive (ScotchBond MP)
2. cavity liner
- calcium hydroxide (Dycal)
- resin modified glass ionomer (Vitrebond)
3. cavity base
- resin modified glass ionomer (Vitrebond, Fuji II LC)

Front 57

materials for use with composite resin

Back 57

1. cavity sealer
- resin adhesive (ScotchBond MP)
2. cavity liner
- calcium hydroxide (Dycal)
- resin modified glass ionomer (Vitrebond)
3. cavity base
- resin modified glass ionomer (Vitrebond, Fuji II LC)

Front 58

Varnish is only used for _______ restorations

Back 58

amalgam

Front 59

dispensing and application of sealer (Scotchbond MP) for use with amalgam

Back 59

kit contains components for amalgam sealing; used as a dual cure system

preparations with the need for additional retention beyond preparation form

1. Etch for 15 seconds
2. Activator mixed with primer, apply to etched preparation for 15 seconds and dry for 5 seconds
3. One drop adhesive and catalyst. Mix together, apply to preparation; place amalgam.

Front 60

Purpose of adhesive

Back 60

- Seal tooth/restorative interface
- Decrease leakage at tooth/restorative interface
- Enhance restoration retention by mechanical locking of adhesive to roughened surface

Front 61

Materials for adhesive procedures

Back 61

- Multibottle: ScotchBond MP
- Single bottle: Optibond Solo Plus

Front 62

smear layer

Back 62

- Layer on tooth surfaces created by rotary cutting instruments
- Made of loosely bound debris, collagen, and hydroxapatite crystals

Front 63

Clinical considerations for indirect pulp capping

Back 63

- Tooth must be vital with no history of spontaneous pain
- Pain elicited from cold test or EPT should not linger
- Restoration must seal tooth from bacteria
- Periapical radiograph demonstrates no periapical pathology
- Tooth will not have casting as definitive restoration

Front 64

Clinical considerations for direct pulp capping

Back 64

- Pulp tissue minimally exposed (usually less than 1 mm in diameter)
- Tooth must be vital with no history of spontaneous pain
- Pain elicited from cold test or EPT should not linger
- Restoration must seal tooth from bacteria
- Periapical radiograph demonstrates no periapical pathology
- Tooth will not have casting as definitive restoration; Critical to success with direct pulp capping
- Control bleeding with damp cotton pellet
- Don’t use explorer tip to verify exposure