Inlay, Onlay, and Veneers Flashcards
Restoration fabricated outside of the mouth:
indirect restoration
Describe the process of impressions for indirect restorations:
impression is take of the prepared tooth and sent to the lab or milled in-office
Inlays, onlays, crowns, bridges, and veneers are all examples of:
indirect restorations
What covers more surface area, an inlay or onlay?
onlay
What materials are used for indirect restorations?
- gold
- lithium discilicate (EMAX)
When should you place an indirect restoration?
- when margin exceeds 2/3 the distance between the central groove and cusp tip
- when margins end 1/2 distance between central groove ad cusp tip
When placing an indirect restoration for a tooth that the margin exceeds 2/3 of the distance between the central groove and cusp tip, you must:
cap weak cusps
When placing an indirect restoration for a tooth that the margins end 1/2 distance between central groove and cusp tip, consider:
capping weak cusps
Indirect restoration that is placed within the cusp tips of a tooth:
Inlay
This type of indirect restoration offers no protection of the cusp from occlusal forces:
inlay
Inlays are used for teeth with: (2)
- minimal caries and strong buccal and lingual cusps
- acceptable (normal) occlusion
Indirect restoration that covers one or more cusp tips, extending through and beyond the cusp tip to the facial/lingual and proximal slopes of the covered cusps:
onlay
Onlays incorporate the principles and advantages of both:
intracoronal and extracoronal indirect restorations
Describe the occlusion with an onlay:
occlusion in all functional positions I supported by restorative material rather than tooth structure
Indications for onlays include: (3)
- large carious lesions
- existing defective restorations
- endo treated teeth
- cracked teeth
Onlays can be used on endodontically treated teeth only when: (2)
they have sufficient tooth structure to retain the onlay and allow for removal of undercuts
and
when enough facial and lingual surfaces are relatively intact
If an onlay is not an option for an endo treated tooth, what should be used?
crown
When do we use an onlay instead of an inlay?
- when the BL width of the cavity preparation is 1/2 distance between central groove and cusp tip
- when the BL width of the cavity prep is 2/3 distance between central groove and cusp tip
- where the cusps are undermined after caries removal
- when the occlusion of the tooth must be altered
Should you do an inlay or onlay in the following scenario?
The BL width of the cavity prep is 1/2 the distance between central groove and cusp tip
CONSIDER onlay
Should you do an inlay or onlay in the following scenario?
The BL width of the cavity prep is 2/3 the distance between central groove and cusp tip
should ONLAY the cusp
An indirect restoration that fully covers the occlusal surface of the tooth and uses the external walls for retention:
crown
What does a crown use for retention?
external walls of the tooth
Why do we do inlays and onlays? (4)
- preference over amalgam
- conserve tooth structure (compared to crown)
- esthetics
- removable prosthodontics abutment
Why would we use an inlay or onlay for a removable prosthodontics abutment?
can better control rest seats and guide planes
Disadvantages of indirect restorations: (3)
- expense
- requires 2 appointments
- impression is needed
Advantages of indirect restorations: (3)
- strength
- conservation of tooth structure
- better control of restorations contours
What are two principles to follow with indirect restorations?
- no undercuts; passive fit
- no sharp line angles
Advantages of gold indirect restorations: (6)
- strength
- wear resistance
- will maintain smooth surface (no tarnish or corrosion)
- better control of contact and contour
- potential for greater longevity
- conserves cementum and periodontal attachment versus restoring with a crown
T/F: With a gold indirect restoration, we have better control of contact and contour especially for large proximal caries where an amalgam would not restore contact and contours:
true
Contraindications for a gold indirect restoration:
- facial or lingual caries or previous restorations (crown is better to restore multiple surfaces)
- need to compare the margin length with that of a crown in some instances
- patients with high caries rate
Why is it a contraindication to use a gold indirect restoration on facial or lingual caries or previous restorations?
crown is better option to restore multiple surfaces
For patients with a high caries rate is a gold indirect restoration a good option?
no
MO gold inlay-
Divergence
- short walls:
- long walls:
Bevel:
NO ____.
short walls: 2 degrees
long walls: 5-7 degrees
Bevel:
1. occlusal = 1.0mm
2. axial pulpal line angle
3. gingival wall = 1.0 mm
NO sharp lines angles
MO gold inlay occlusal internal form =
2.0 mm deep
Do you dovetail a gold inlay prep? Explain:
Yes- prevents distal displacement
Do you use a reverse S curve in a gold inlay preparation?
NO- prep is more straight and angled; gold has strength at edge (whereas amalgam doesn’t)
What is the adequate proximal clearance of a gold inlay preparation?
0.5 mm with smooth proximal walls
What is the function of a bevel?
protects enamel from fracturing
Ceramic inlay-
Occlusal depth=
Isthmus width=
Pulpal walls=
F, L, G margins should clear contacts by atleast:
occlusal depth: 1.5-2.0mm
Isthmus width: 2.0 mm
Pulpal walls= smooth & flat
F,L,G margins should clear contacts by atleast 0.5mm
For a ceramic inlay, facial and lingual walls MUST:
diverge
For a ceramic inlay, need ____ Insertion and garter than a _____degree taper
passive insertion; 2-5 degree
For a ceramic inlay, the restoration ___ to the preparation walls
BONDS
The base of the main cavity for a ceramic inlay should be:
flat
In a ceramic inlay, occlusal margins may not coincide with:
occlusal contacts
In a ceramic inlay, margins should be prepared to a ____; alternatively they should present a hallow ____ in an attempt to create an “invisible” margin
90 degree cavosurface line angle; ground chamfer
If a prep gets too wide, you must:
onlay either buccal and/or lingual cusps
An inlay acts as a ____ whereas an onlay ____
wedge; protects
For an onlay, we need ____; This is NOT the same as ___-
occlusal clearance; reduction
The amount of space between the teeth:
clearance
The amount of tooth structure removed:
reduction
Gold onlays:
Depth cuts
- lingual (functional cusp):
- facial:
lingual: 1.5mm
facial: 1.0mm
What cusps are beveled with a gold onlay?
both non-functional and functional cusps
In gold onlays, the retention from short axial walls =
2 degree divergence
The main principle for gold onlays, is to cover:
both facial and lingual cusps of maxillary and mandibular teeth
What is the minimum amount of gold to cover cusps of SUPPORTING occlusion in a gold onlay?
What is the minimum amount of gold to cover cusps of NONSUPPORTING occlusion in a gold onlay?
1.5mm
1.0 mm
Describe the bevel on cusps supporting occlusion in a gold onlay:
Describe the bevel on cusps NOT supporting occlusion in a gold onlay:
REVERSE bevel of 1-2mm
REVERSE bevel of 0.5 mm
What is an exception for cusps coverage with gold onlays? (typically both facial and lingual cusps are covered)
exception for esthetics on maxillary teeth