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.