MOUTH PREP PART II

Rationale for Rest Seat Preps?? (2)

Provide adequate space within the contour of the tooth to recieve the rest

Direct forces to long axis of tooth

Posterior Rest Types?? (2)

Occlusal

Embrasure

Anterior Rest Types????? (5)

Cingulum

Cingulm Alternative

Cast cingulum

Composite Cinuglum

incisal

Occlusal Rest Seat Form:

Shape?

No _______ (3)?

What type of walls?

Rounded triangular (spoon)

Sharp angles, walls or interlocking featres

expulsive

Occlusal Rests need to have a _____ seat: Why?

Apex must be deeper than _____

Less than ____ degrees between ______ and ______

Positive - direct force along long axis of tooth

Marginal Ridge

90 - floor and minor connector

Occlusal Rest Dimensions:

MD?

BL?

1/3 width

1/2 intercuspal at base or 1/3 width

Occlusal rests are larger in what two types of teeth?

Molars and surveyed crowns

Dimension of Occlusal Rest at marginal ridge (how much clearance is needed)

1-1.5mm???

You should make the _____ before cutting a rest seat?

Guide plane

Occlusal rests are located where?

When is it more lingual?

Next to edentulous area

When it originates from the embrasure

Indications for embrasure rest seat?

Classes?

Double retention/support needed

Class II, III, IV without mods (indirect retainer for class lV)

Embrasure rest seats are indirect retainers in what class?

Class IV

Embrasure rest seats must allow access for what two things?

What surfaces?

Do not break what?

Minor connector - lingual

Clasp arms (buccal)

Contact

What are the two Cingulum rest seat forms?

Where are they used?

Inverted V - prominent cingulum (maxillary)

Flat edge (mand anterior)

What teeth usually do not use alternative cingulum rest?

Why?

mand canines

don’t display sufficient enamel

A cingulum can be ______ and ______ to the tooth

Casted and cemented

Incisal rest seats:

Placed on the _____ or _____ of _____ teeth

Usually done on what tooth?

_______ inferior to ______ rest

M or D incisal angle of incisor

Mandiblar incisor

Mechanically - cingulum

What type of rest seat is not common and rarely used?

Why?

Incisal rest seat

Not aesthetic

Rank Best to worst restorations to place rest seats over?

Unaltered enamel or metal

PFM crown

Occlusal amalgam or composite

Class II amalgam or composite

Enamel Perforation is what?

Exposed Dentin

When do you need to notify your patient about enamel perforation?

Prior to teeth mod

If dentin becomes exposed, what should you do?

Offer pt fluoride therapy and maintain regular recall

What may be beneficial when large areas of dentin become exposed?

Restoration

Perforation in a surveyed crown is corrected by ______ the perforation using a ____ bur and placing a _____ restoration

enlarging

round

amalgam