Complex Direct Restorations

Evaluation of resistance form becomes complicated as the preparation becomes less conservative. Removal of ___ could severely compromise restoration retention.

unsupported enamel

but you still, obviously, want to remove as much decay as possible (if not all)... it is uncomfortable to leave unsupported enamel, but may be necessary

Primary retention of restorations is derived from ___

opposing walls

Retention form decreases if cavity walls are ___ or ___

shortened

removed

Preparation design will be guided by the ___ planned

type of restoration

What are some of the different types of restorations?

final

foundation (leading to a crown)

temporary

Temporary gives you more time to decide what you want to do/what is best... ___ and ___ are required at a later date

re-evaluation

replacement

When placing a final restoration, you need to be sure that ...

no other (pre-planned) procedures will be done on the tooth

do it once, and don't plan to touch/change it again

For a final restoration, ___ and ___ should be maximized

retention form

resistance form

Give an example of a final restoration:

a crown

Give an example of build up:

working on the tooth and building a structure that the crown can comfortably and reliably sit on

For a final restoration, you need to ___ and ___ weakened tooth structure (before placing it)

reduce

cap

A foundational restoration, or "build up," is a complex restoration prepared in such a manner that the restorative material will serve in lieu of tooth structure in subsequent procedures for developing the ___

final restoration (crown prep)

Basically, the build up is the ___ to the final restoration

precursor

you leave it there and place final restoration on top!

Restorative material must be ___ of tooth structure that may be removed during subsequent preparation

independently retentive

this is talking about the build up!

Essentially, foundational restorations are completed when a patient eventually wants a ___

crown

"completed" means covering the build up to finish the protocol

Crown preparation requires uniform removal of ___ of tooth structure circling the base of the crown

1-1.5 mm

Crown preparation also involves reducing tooth structure in a manner that ...

maintains the anatomy of the tooth, while also giving you space to place the crown on top in place of the tooth structure that was there previously

Temporary restorations are used to restore a tooth temporarily (obviously) or for ___ purposes

caries control

Temporary restorations can be dependent on ___ for support

remaining unsupported tooth structure

Replacement of the temporary restoration with a ___ or ___ restoration is anticipated

final

foundational

(technically both, foundation —> final)

In addition, another option after a temporary restoration has 'expired' is to ...

remove the tooth

(foundational —> final route is if you want to keep the tooth)

___ weakened cusps increases their resistance form

Capping

Cusp capping is necessary for adequate resistance form when ___ severely undermines enamel (of the cusp)

decay

Cusp capping is required when facial/lingual extension of the prep is ___ from the primary groove toward the cusp tip

2/3

What aspects should be evaluated when deciding about a cusp cap?

esthetics

occlusion

parafunctional habits

opposing dentition

arch location

You can decrease the potential for tooth fracture by ___ and ___ weak/unsupported cusps

reducing

capping

What is the difference between reduction and caping?

reduction is partial, while capping is complete

How much are you required to reduce a supporting cusp?

2 mm

How much are you required to reduce a non-supporting cusp?

1.5 mm

You can use ___ to measure reduction

bur dimensions

(depth cuts) — place next to tooth before you drill into it

What is the name of the thick veneer kit bur that is used to cap cusps?

6845KR

Capped cusps should be ___ or have ___ when looking at their vertical positioning

flat

slight inward slopes

Capped cusps cannot have ___

outward slopes

A ___can be used to measure reduction

perioprobe

Another reason, besides undermining decay, for a cusp cap is when cusp have ___

incomplete fractures

Incompletely fractured cusps can be identified using a ___

bite stick

Which cusps are more frequently affected by incompletely fractured cusps?

maxillary buccal

mandibular lingual

(the non-supporting cusps)

___ teeth, synonymous to incompetent fractured teeth, require cusp capping, as indicated by pain on biting & sensitivity to hot and cold

Cracked

Cracked teeth experience pain especially on ...

release of biting pressure

T/F: radiographs give you conclusive evidence as to cracks in teeth

false, for the most part

When dealing with a cracked tooth, you want to do your best to prevent ___

losing the tooth

Diagnosis of cracked teeth depends on ___ and ___

dental history

subjective examination

Dental history... how is this implicated?

if cracked teeth are a recurrent issue for a patient, perhaps they have a bruxism problem

Explain subjective examination:

ask patient to point to sensitive tooth

ask if they bit into a hard object

ask about any damaging habits, such as chewing on ice, pens, etc.

...pain could be due to eating hot pizza, it is not always a medical issue

Diagnosis of cracked teeth can also involve ___ and ___ examinations

visual

tactile

Tooth surfaces should be checked in a ___ field when evaluating for cracks

dry

Beyond using bite sticks to identify cusps in need of capping, ___ can also be utilized

tooth slooths

Tooth slooths are useful, because they can be used to identify cracks on ___

specific cusps

T/F: when using a tooth slooth for a bite test, if there's no pain, there's no crack

false

cracks can be present without pain! but this is rare

A ___ can also be used to gauge a tooth for cracks

perioprobe

(feel around for roughness)

Cracked teeth barely show up on x-rays, but you can increase chance of detection of defect by taking periapicals from ___

more than one angle

What are some radiographic clues of cracked teeth (useful if you can't see the crack itself)?

restorations with pins

widened PDL space

endodontically treated teeth

diffuse longitudinal radiolucency

posts

perforations

internal or external resorption

Removal of ___ sometimes exposes cracks underneath them

restorations

___ may also disclose a crack, although they can additionally mean 100 other things as we have learned before

Stains

___ is a useful, but often misleading way to identify cracks within a tooth structure

Transillumination

(will highlight normal cracks, too)

What are normal cracks called?

craze lines

TI: cracks will ___ light, while craze lines will ___ it

block

transmit

___ should only be utilized to gauge presence of a crack if a crack is highly suspected, but not confirmed by all other diagnostic means

Surgical assessment

Surgical assessment is especially useful for confirming the presence of cracks on the ___ of a tooth

root

How do you treat incomplete cusp fractures/cracks?

remove affected cusp (cap it)

restore tooth to cover cracked margin, using onlay, amalgam, or crown

do RCT is pulp is involved

What is a split tooth?

tooth cut into pieces due to a large crack

What are the symptoms of a split tooth?

marked pain to chewing

significant soreness of jaw or gingiva

deep periodontal probing depth

Do you keep the tooth if it is cracked?

no; you get rid of at least one of the cracked portions, only leaving one piece of tooth (if any)

If a crack leaves a middle or coronal third, you ...

remove the smaller segment

restore remaining segment

only extract if there is a perio defect

If a crack leaves an apical third, you ___

extract the whole tooth — both segments

Coronal/Middle/Apical refers to ___ of crack

depth

Vertical root fractures are often indicated by ___ and ___ as per radiographic evidence

marked bone resorption

radiolucency

Just to clarify, real quick, capping a cusp involves both ___ and ___

full reducing it

restoring it (back to normal shape)

If you see a crack running towards the pulp chamber, on the occlusal of the tooth, it is often best to ...

just fill it with amalgam or composite

what??? doesn't quite make sense... at all.. but it was said in lecture

A cap cusp should be at the same level as the ___, but it doesn't have to be

pulpal floor

This ^^ happening or not depends largely on location and extent of ___

decay

however, in preclinic, we tend to match cusp reduction to pulpal floor

Sound tooth structure can be reduced during cusp capping in order to provide ___, which is extremely critical

more retention

If primary retention (cavity walls) is compromised, the need for ___ features must be evaluated

secondary retention

Secondary retention feature options include ...

slots

grooves

boxes

A slot is located in ___, on a ___ plane

dentin

transverse (horizontal!

Slots should be prepared with a ___

33.5 inverted once bur

T/F: short slots are less effective than long slots

false

equally effective!

Grooves/locks have length in the ___ plane and are located in ___

longitudinal (vertical)

dentin

You can use a ___ or ___ bur to create grooves/locks

169L

.25/.5 round

Grooves/locks are deepest at the ___

point angle

You use ___ to avoid the DEJ when creating a groove/lock

translation

(just keep it in dentin, don't extend into enamel)

What is a shoulder?

a 90-degree horizontal margin design used in crown preparations, typically 1.0-1.2 mm deep

A key way to maintain resistance form of a shouldered + capped cusp prep is to round the ___

axiopulpal line angle

Is amalgam bonding recommended?

not really

barely contributes a benefit