7. Onlay Procedure Flashcards
An onlay is:
vA restoration that restores the ____ surface of the tooth as well as one or more ____
vA restoration that restores the ____ and ____ surfaces of the crown of the tooth
vA restoration that involves one or both ____ surfaces
occlusal cusps internal external proximal
An onlay is:
vConsidered an ____ and ____ restoration
vIt is an ____ procedure
intracoronal
extracoronal
indirect
Extracoronal Restorations and Occlusion:
vOcclusal forces transmitted through an onlay restoration, tend to hold the cusps together because the ____ have been incorporated into the restoration
cusps
Onlay Indications
v Indicated when the buccal or lingual isthmus outline is ____ the distance from the central groove toward the cusp tip
two-thirds
Onlay Indications
v Indicated when the buccal-lingual isthmus width is more than ____ the distance between the buccal and lingual cusp tips
half
Onlay Indications
v Necessary for adequate ____ form – to overlay a ____ cusp
or a ____ cusp
resistance
weakened
broken
Onlay Indications
v Can replace broken cusps when there still is remaining enamel supported by ____ on the buccal and/or lingual surfaces.
dentin
Onlay vs. Crown
v Can be a ____ alternative to a full coverage crown
conservative
Onlay Preparation vs. Crown Preparation
v A more ____ preparation than a crown preparation
v Onlay has ____ margins -
vless ____ to gingiva than full crown preparation
conservative
supragingival
irritating
Onlay Contraindications
Choose full coverage crown when:
v The onlay preparation final margin areas would be in areas of ____
v The remaining buccal and lingual tooth structure is without ____
decalcification
supporting dentin
Advantages
v Preserves ____ structure – less reduction than a crown
v Prevents the ____ that may lead to fracturing of fragile cusps
vMore precise ____ over contours and contacts
vImproved access and visibility
• Fabricated on a ____ outside the mouth
tooth
stresses
control
die
Disadvantages of an Onlay v Multiple \_\_\_\_ v \_\_\_\_ (interim) restoration v Laboratory \_\_\_\_ v \_\_\_\_ sensitive
appointments
provisional
cost
technique
Onlay Options
v ____
v ____
cast gold
porcelain
Porcelain Onlay
Porcelain onlay preparation maxillary first molar
Buccal view of completed onlay
YAY
Porcelain Onlay
Indications specific to Porcelain Onlays:
v Areas of ____ importance
v Areas of ____ defects or failing previous restorations
v ____ sized lesions
esthetic
large
moderate
Porcelain Onlay
Contraindications specific to Porcelain Onlays
v Areas of heavy ____ wear
v ____ history
v Lack of ____ enamel
v Inability to maintain a ____ field
v Deep ____ preparations
• Want gingival margins in ____ – best bond
occlusal bruxism occlusal dry subgingival enamel
Specific Advantages of Porcelain Onlays
Ability to strengthen remaining tooth structure
v____ bonded
vReduced ____ vs large composite restoration
adhesively
polymerization shrinkage
Specific Disadvantages of Porcelain Onlays
v ____ of porcelain onlays:
vCeramic can fracture without adequate ____ vCan fracture during ____ in or after cementation
vWears ____ dentition and restorations
• Particularly if ____ and unpolished
brittleness thickness try opposing rough
Porcelain Onlay Preparation
vTooth reduction varies between ____ and non functional cusps
vReduction will mimic ____ anatomy of the cusp being reduced
vAll areas should have a common ____
• All walls are ____
functional
original
path of draw
divergent
Porcelain Onlay Preparation
1. Prepare an “overcut” MOD preparation \_\_\_\_ or tapered diamond bur \_\_\_\_ mm isthmus buccolingually \_\_\_\_ mm depth \_\_\_\_ walls 2. Use tapered fissure bur remove \_\_\_\_ 3. Internally \_\_\_\_ angles are important
171 2-3 2 divergent undercuts rounded
Porcelain Onlay Preparation
- Proximally, extend to just break ____
- Check all areas have common path of
draw-____ - NO ____ - ____
joint cavosurface - NO ____ contacts in MIC directly on ____ areas
contact divergent bevels butt occlusal margin
Porcelain Onlay Preparation
9. Occlusal reduction/cusp reduction: v use tapered fissure bur (171) v Follow \_\_\_\_ planes of occlusal anatomy v Reduction: • Functional cusp: \_\_\_\_ mm • Non functional cusp: \_\_\_\_ mm
geometric
2
1.5
Porcelain Onlay Preparation
Occlusal reduction
v Follow original ____ contours
cuspal
Porcelain Onlay Preparation
Check occlusal reduction in MIP and excursion
-Use a softened piece of ____ to check the bite: Make an imprint of the bite in MIP and measure the wax ____ with a periodontal probe where the cusp used to be
pink wax
thickness
Porcelain Onlay Preparation
10. Occlusal shoulder - On the ____ surface of the cusp being covered
v Added with tapered fissure bur
v ____ mm wide axially
v Placed in the ____ third of the cusp O/G
v ____ joint – NO ____
outer 1-1.5 middle butt bevels
Porcelain Onlay Preparation
____ external and internal angles
____ mm axial reduction
____ joint shoulder margin
____ mm non functional (L) cusp occlusal reduction
rounded
1-1.5
butt
1.5
Procedure for Porcelain Onlay
____ mm non functional cusp (L) shoulder reduction
Check with ____ mm hatchet width
____ mm proximal contact opening
Check with ____ mm hatchet thickness
1
small 1
0.75
small 1.0
Procedure for Porcelain Onlay
____ mm non functional cusp (L) occlusal reduction
Check with ____ in MIP to measure occlusal reduction
1.5
pink wax
Summary
v An excellent alternative to direct composite restorations
v More ____ than full-coverage restorations
v Very ____ sensitive
• Proper case selection
• Operator skill
• Attention to detail
conservative
technique
Provisional Restoration
vAn ____ restoration cemented into the preparation until the final restoration is delivered
v“Temporary” – ____ more correct
vMade of ____ or composite materials
interim
provisional
acryclic
Provisional Restoration
A Provisional should:
v____ the tooth
vmaintain the health of periodontium
vmaintain the ____ of the prepared tooth in the arch
vmaintain position of ____ and opposing teeth
protect
position
adjacent
Provisional Restoration A Provisional should (continued): vprovide \_\_\_\_, phonetic, and masticatory functions vhave adequate \_\_\_\_ and retention vnot be \_\_\_\_
esthetic
strength
irritating
Provisional Restoration Composite Resin Procedure
vBefore tooth preparation, roll hard body ____ putty into a hot dog shape and place it on the tooth being prepared to make an impression.
vCapture the tooth and both ____ teeth in the impression
v“____”
polyvinyl siloxane
adjacent
putty shell
Provisional Restoration Composite Resin Procedure
vLubricate preparation with ____. Use a brush and coat the tooth well
vPlace composite provisional material into molded putty shell
vaseline
Provisional Restoration Composite Resin Procedure
vSeat Putty shell fully onto preparation
vWait ____ minutes
-Remove putty shell from arch
-Refine Carefully trim away excess
1.5-2
Provisional Restoration Composite Resin Procedure
vVERY carefully perform minor last adjustments on the prepared tooth
vDO NOT DAMAGE THE TOOTH OR THE PREPARATION
YAY
Provisional Restoration Composite Resin Procedure
Final try in and margin check
Check and adjust occlusion
YAY
Provisional Restoration Composite Resin Procedure
Provisional is cemented with a “temporary” ____ cement
non-eugenol
