Inlays, Onlays and Veneers Flashcards
Describe the clinical stages in indirect restorations?
Preparation
Temporisation
Impressions and occlusal records
Cementation
What is an inlay?
In direct restoration- Intra-coronal restoration made in the lab.
Filling made in the lab.
What are the uses of inlays?
Occlusal cavities
Occlusal/interpoximal cavities
Replace failed direct restorations
What materials may be used to make an inlay?
Gold- Type IV hardened
Composite
Ceramic- Alumina Feldspathic porcelain
Metal
What are the indications for an inlay?
Premolars or molars
Occlusal restorations
MO or DO
MOD if kept narrow- if not then consider an only.
Low caries rate.
What are the advantages and disadvantages of inlays?
Advantages- superior materials and margins, won’t deteriorate over time.
Disadvantage- time and cost.
Describe the preparation of an inlay?
Isthmus width first
Flat pulpal floor- roughly 1.5mm
Margins clear of occlusal contact areas
No undercuts.
Taper the cavity at 4-6 degrees
Shoulder or chamfer margins supragingivally
If ceramic- butt joint CSM, if gold then 15-20 degrees bevel.
Clear adjacent tooth contacts
Occlusal key/dovetail
Rounded internal line angles at the angle of the pulpal floor to the gingival floor.
Describe the sequence of events at the initial preparation phase of an inlay?
Take 2 putty impressions first- use one to make a reduction guide and another used to fabricate the temporary restoration.
Take a shade.
Mark up occlusal contacts.
Prepare the tooth for the inlay.
- Ensuring to block out any undercuts.
Make temporary inlay using the putty impression- ProTemp (chemically cured bis-acryl), Kalzinol, GI.
Take an occlusal record- wax bite or bite registration paste.
Take master impressions using impregum (polyvinylsiloxane).
Cement in temporary inlay.
Send impressions and occlusal records to lab to make the inlay.
What do you want to tell the lab on your lab card for the inlay?
Pour impressions
Mount the casts on a semi-adjustable articulator using the wax bite/occlusal record provided.
Construct restoration
- tooth
- material
- thickness
- shade
- Characteristics
What cement would you use for a ceramic or gold inlay?
Ceramic- NX3 or RelyX
Gold- Aquacem
Metal- Aquacem or panavia
Composite- NX3
What is an onlay?
Extra-coronal restoration made in lab.
Same as an inlay but it has cusp coverage.
What materials might an onlay be made from?
Gold
Composite
Porcelain
What are the indications for placing an onlay?
Sufficient occlusal tooth substance loss- buccal and/or palatal/lingual cusps remaining.
Remaining tooth substance weakened- caries, pre-existing large restorations.
What cases might an onlay be useful?
Toothwear cases- increase OVD
Fractured cusps
Restoration of root treated teeth
Replace failed direct restorations
Remaining tooth structure is weakened by caries or large restorations.
Describe the prep required for an onlay?
No undercuts
Chamfer or shoulder margins
Bevel of 4-6 degrees
Smooth internal line angles
Flat pulpal floor at an even depth
Margins clear of occlusal contact points
Cusp reduction- depends on material and whether the cusp is working or non-working cusp.
- Ceramic- working cups is 2mm reduction and non-working is 1.5mm reduction.
- metal- working cusp is 1mm reduction and non-working is 0.5mm.
proximal box is 1mm- improves resistance and retention.
What cement would you use for a ceramic or gold onlay?
Ceramic- NX3 or RelyX (resin)
Gold- Aquacem
Describe the contents of the second appointment for an inlay/onlay?
Remove the temporary
Isolate, clean and dry the prepared tooth
Try in, assess fit adaptation, occlusion.
Cement
Minor occlusal adjustments if needed.
What are the alternatives for an inlay/onlay?
Direct restoration- amalgam, composite or GI
Crowns
Extraction
What is a veneer?
Thin layer of cast ceramic or bonded composite that is bonded to the labial or palatal surface of a tooth.
Explain to patients that it is like an acrylic nail that is glued onto the front of your tooth with minimal preparation of the natural tooth.
What material may be used for a veneer?
Ceramic
Composite
Gold
What are the indications for veneers?
Discolouration
Enamel defects
Correct peg laterals
Improve aesthetics
Change tooth shape and/or contour
Reduce or close proximal spaces and diastema
Align labial surfaces of instanding teeth
What are the contraindications for veneers?
Poor OH
High caries rate
High smile line
Gingival recession
Root exposure
If extensive prep required- greater than 50% of surface area no longer in enamel
Labially positioned, severely rotated and overlapping teeth
Extensive TSL/insufficient bonding area
Heavy occlusal contacts
Severe discolouration
Describe the preparation required for a labial veneer?
Incisal reduction- 1-1.5mm, remember incisal bevel.
Mid-facial reduction 0.5mm within enamel
Cervical reduction- 0.3mm, slight chamfer margin within enamel, supra gingival or slightly sub gingival.
Sometimes no preparation is required.
What impressions are required for a veneer?
Putty index for guide
Putty index for temporary
Master impression to send to the lab for fabrication of ceramic veneer (not required for direct composite veneer).
What is the Gurel technique?
Take an impression
Send to lab to get cast and wax up the veneers on the cast.
Take a putty impression of the cast with the wax up- creates a mock up guide.
Put the guide against the patient’s natural teeth and see where the veneer is thick enough.
With the guide, place some temporary materials (flowable composite) into it and then sit it onto the patient’s teeth, let it set (light cure) and then you have an intra-oral wax up to show the patient (aesthetic pre-evaluative temporaries)
Do a standard veneer preparation through the mock up of the patient’s teeth.
What cement is used for veneers?
NX3 or RelyX
Make sure to use matrix strip or PTFE on the inter proximal surfaces- remove excess using microbrushes before the cement sets.
Describe the content of the 1st appointment for a veneer?
Administer LA if required
Make putty index and separate impression for temporary and impressions for the lab
Send impressions to the lab for them to cast on an articulator and make a diagnostic wax up (gurel technique)
Prepare the tooth
Make the temporary veneer using the template
Master impression, bite registration and record shade.
Cement in temporary.
Send to lab for fabrication of definitive veneer
Describe the contents of the second appointment for a veneer?
Remove temporary
Isolate, clean and dry the prepared tooth
Try in, assess fit, adaptation and occlusion
Cement in place with NX3 or RelyX.
What alternative might you consider instead of veneers?
Microabrasion
Resin infiltration
Direct composite restorations
Crowns
What are the uses for different materials used for indirect restorations?
Lithium Disilicate (EMAX)- very aesthetic, good flexural strength (similar to tooth structure)
Precious metal (gold)- strongest material, less abrasive but not suitable for aesthetic cases and is expensive.
Zirconia- Much stronger than Max but aesthetics aren’t as good, more abrasive than metal.
Porcelain fused to metal- metal cervical area may become visible due to gingival recession.
Describe the contents of the first appointment for an onlay prep.
Full history and examination.
Re-check occlusion, guidance and reference points prior to prep.
Administer LA and apply dental dam.
Take a sectional impression of the tooth- 2 impressions- one to make a temporary and one as a guide for reduction of the tooth.
Remove previous restorations, remove all caries and carry out dentine sealing.
Assess the tooth at this stage- do I need a core?
Prep the tooth for onlay- occlusal reduction first, the axial and proximal.
Cuspal reduction, 4-6 degree tapered walls, 1-1.5mm marginal reduction.
Flat pulpal floor, shoulder/chamfer margins, rounded internal line angles.
Create temporary onlay using the impression.
Take definitive impression and bite registration.
Cement the temporary in place.
