What burs are used for veneers?
Depth cutting burs (e.g. Komet 834)
Technik 856
What are the steps in prepping a veneer?
- Use Komet 834 depth cut bur to reduce labial surface by 0.5mm (thickness of cement + veneer generally add to 0.5mm) (0.3mm burs also available)
- Reduce incisal surface by 1.5mm using technik 856 (may do 1-1.3mm initially to allow for polishing), nb: thickness of end of bur is about 1mm
- Use technik 856 to reduce labial surface in two planes, extend to near proximal area and follow gingival contour (nb: in clinical situation would take margin JUST under gingival tissue, but no deeper (2mm is too far subgingival and cause permanent inflammation))
- Extend the gingival margin further interpoximally so that when looking at tooth distally + mesially while it is in the arch should see finishing margin not a triangle of unprepped tooth structure towards the gingiva)
- Define the margin with the intermediate speed technik 856 (creating 0.5mm chamfer) and use komet 8877 to take prep to the contact point (basically similar princinple to breaking through contact with L10 BUT not going all the way through this time, only reach contact area)
*DO not bevel joint between incisal and palatal, leave it as a butt finish to allow for thickness of material
What is a shell crown?
-Basically a relatively conservative crown on anterior teeth made of ceramic (basically a ceramic veneer extending around the entire tooth)
How do you do a shell crown prep?
- Prepare the labial the same way as preparing a veneer
- Open the contacts with an L10 bur
- Create 0.5mm fine chamfer margin interproximally with 8877
- Create 0.5mm fine chamfer margin on the lingual cingulum area (gingival 1/3) with 8877
- Take 0.5mm off concave area on the lingual (incisal 2/3) with high speed F40 and Horicon 239
- Smooth over preparation with technik 856 and round all angles (including the butt finish from the veneer prep)
*NB: can not have sharp edges with ceramic preps
How can preps be rounded?
Angle bur 45 degrees to the sharp edge and reduce slightly
How do you cement a veneer or shell crown?
Acid etch enamel
Bonding resin
Resin cement
Veneer
What are veneer failures associated with?
Aesthetics
Mechanical complications (increased by parafunction)
Periodontal support
Loss of retention (increased when bonded to retained restorations, not bonded to enamel)
Caries
Tooth fracture
What material is used in veneers/
Feldspathic glass, may have leucite filler
What are the factors that determine successful treatment?
- Good case selection
- Thorough treatment plan
- Communication, verification of pt satsifaction
- Properties and limitations of materials
- Good clinical technique (tooth prep/impressions, cementation)
- Good lab technique
- Recall and maintenance
What are the indications for veneers?
- Diastema closure
- Alter tooth shape, colour, contour, position of tooth
- Mask tooth surface anomalies (e.g. tetracycline, hypo/hyperplasia)
What are the advantages of veneers?
- Excellent aesthetics
- Alloy free
- Good clinical record especially with porcelain veneers
- Conservative restoration
What are some limitations of veneers?
- Covering dark stains
- Correcting severe malpositions/angulations
- Fragile
- Post insertion sensitivity
What are the rules to follow when preparing a veneer prep?
- Keep in enamel
- Margin must be at gingival crest or subgingival
- Proximal extensions must be present
- Do the correct reductions
What should you do if you hit dentine while doing a veneer prep?
-Convert it to a crown
What impression technique should be used?
- Apply adhesive to tray
- Extrude light body around tooth
- Extrude heavy body into tray
- Insert tray and allow to set
- Remove tray
What are some things to consider when temporising veneers?
- Tend to debond
- Tooth sensitivity could be an issue
- Use resin based or eugenol free cement
What are some common causes for marginal leakage under temporary veneers?
- Poorly fitting temporaries
- INadequate cement seal
- Long term temporisation
- Smoking, coffee, tea, food
What temporary cement should be used to cement temp veneers and why?
Tempbond clear: colour does not show up beneath veneer (note difficult to remove excess)
What cement should be used to cement permanent veneers?
- Nexus III
- RelyX Veneer
What are the steps to cementing a permanent veneer?
- Ask patient about tooth sensitivity
- Check veneer for chipping and fit on master die
- Clean tooth surface
- Seat veneer and check contact, contour, shape and shade of veneer and fit as well; check patient satisfaction
- Prepare veneer and tooth surface for bonding and cement with resin cement as per manufacturer instruction
*Can suggest patient bring someone else at consult to help assess veneer
How should the tooth surface be prepared to bond with veneer?
How should Sinfony veneers be prepared prior to bonding?
How should porcelain veneers be prepared prior to bonding?
Tooth Etch 15 seconds Wash Gently dry Optibond Solo Plus for 15 seconds and air dry for 3 seconds Light cure 20 seconds
Sinfony (resin):
Sandblast with rocatec soft
Apply silane
Gently air dry
Porcelain
- Etch with 9.5% HF acid
- Rinse with water
- Apply silane
- Gently air dry
How is the veneer cemented after preparation is done?
-Apply cement to veneer
-Seat
-Light cure 40 seconds
(Varies e.g. light cure time according to the different type of cement, but more or less follows these steps)
How should the final veneer be polished after cementation?
- Diamond polishing paste
- Applied with rubber cup in slow speed
What are some possible veneer failures? What can cause them?
Incisal chipping
- Trauma
- Parafunction
- Fabrication defect
- Insufficient reduction
- Binding of veneer during cementation
Fracture:
- Fabrication defect
- Insufficient tooth reduction
- Trauma
- Parafunction
- Binding of veneer during cementation
- Incorrect handling
- Binding of veneer during trial fitting
Attachment loss
- Trauma
- Parafunction
- Poor enamel quality
- Cementation flaw (incorrect mixing, premature setting, incorrect tooth conditioning)
Marginal leakage
- Poor marginal fit
- Incorrect cementation
- Marginal contaimination
- No enamel margin
- Poor oral care/cervical plaque deposit
Periodontal problems
- Poor oral care
- Encroach biological width
- Overcontoured cervical margin
- Cement overhang
- Marginal opening
Gingival recession
- Overeruption
- Encroach biological width
- Cervical fracture/incisal wear
- Fabrication defect
- INsufficeint reduction
- Trauma
- Parafunction
- Poor adhesion
- Binding of veneer during cementation
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PBM and PBZ20
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Sim Clinic Standardised Measurements4
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Post and Core75
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Full Gold Crown10
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Temporary Crowns17
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Veneers30
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Onlays11
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Bridges_Intro27
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Resin Bonded Cast Alloy Bridges24
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Cements51
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EMAX Crowns29
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Ceramics and Resins21
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Soft Tissue Management_Surgery13
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Aesthetics and Shade Selection10
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Impressions17
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E4D CADCAM4
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Soft Tissue Management_Retraction14
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Resin bonded Fibre Reinforced Composite Bridges6
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Fixed PRos For Periodontally Compromised Teeth7
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Pontics12
