5 - Indirect restorations

Can teeth fully recover their strength with ceramic inlays/onlays and composite cements?

Yes

What materials are used for direct and indirect restorations?

What are the diferences between composite and porelain as a restoration material?

Inlay vs Onlay vs Overlay vs Veneers vs Crown

Inlay - doesnt cover any cusps (intracoronary)

Onlay - covers any cusp

Overlay - covers entire occlusal surface

Veneers - Vestibular surface

Crown - covers entire tooth incl. cervical portion

What are indications of Indirect restorations? (learn 5)

• Weakened teeth

• Widely destroyed tooth

• Correct malocclusion and abrasions

• RCT teeth (m + pm cusp protection)

• Partial denture support

• Fixed prostheses pillar

• Subgingival restorations

• Large Class 1 or MOD (class 2)

• Close diastema and improve contacts

What are contraindications of indirect restorations?

• Small defects

• High caries activity

• Inadequaate retention

• Short clinical crown

• Young teeth (large pulp chamber)

• Deciduous teeth

What are disadvantages of indirect restorations?

• Retention by adhesive cement

• Complex cementation

• Mutiple clinical laboratory phases

• Higher cost

• Agressive cavity prep

• More detailed prep required

• Less retention than full crowns

What are the advantages of indirect restorations?

• Save tooth structure

• Colour stability

• Visible and accessible margins to cavity prep for cleaning

• Indirect materials have less tendency to stress and wear

• Anatomical reproduction and good finish

• Lower rate of volumetric changes

How do you prepare a tooth for an Inlay?

Class 1 or 2 cavity preparation

Diamond bur, taperd flat head and rounded tips

Divergent walls 10-15°

Isthmus max width 1.5-2mm

Occlusal plane 1.5mm depth and perpendicular to path of insertion

Proximal boxes more that 1mm axial depth, and 2mm b/l

Remove contact points

No bevel

What is a good restoration option for large restorations of posteriors after RCT that still have healthy walls?

Onlay

How is a tooth prepared for an onlay?

Conical diamond bur with rounded tip

No contact point between cavity margin and adjacent tooth

Axial reduction with conical flathead and round tip bur, with deep chamfer

No sharp angles

No bevels

90° cavosurface angle

At least 0.5mm gingival enamel (good marginal seal)

No occlusal contact on restoration - tooth interface

1.5 - 2mm thickness for cusp coating

How is an overlay made?

CAD/CAM in lab

(note that chamfer margin is needed in overlay prep, similar to onlay)

How are provisional restorations made for inlays?

Temp filling cement (e.g. Fermit).

Impression not needed

How are provisionals made for onlays

Use Protemp, direct technique

Alginate/silicione impression needed

Cement provisionals without eugenol (temp-bond)

What does the first clinical session consist of?

Xray, impressions for provisionals, remove caries and prep tooth.

Definitive impression for lab to make indirect restoration

Wax occlusal register

Cement provisional restoration

What does the second clinical session consist of?

Remove provisional and clean the tooth

Insert and cement restoration

Consider contact points, marginal adjustment, stability, aesthetics, Occlusion

How do we complete absolute isolation before cementation?

Apply a resin barrier (the same type used in tooth whitening) to protect the gums

Cure for 20 seconds

Use Teflon tape on adjacent teeth to prevent bonding

Different ceramics need different etching times and acids- what is used for the inner side of ceramic vs silicate porcelain?

9.6% (yellow) hydrofluoric acid for 2 minutes (ceramic)

4.9% (red) hydrofluoric acid for 20 seconds (silicate porcelain)

After HF etching- etch with orthophosphoric acid for 30 seconds, apply silane for 1 minute

What does the total etching of enamel and dentin, and the adhesive application consist of.

Etch enamel with 37% orthophosphoric acid for 30 seconds, etch dentin for 20 seconds, rinse and gently air dry

Apply dual adhesive on tooth and restoration on inner surface

What adhesive should you use for what cement?

Dual cement - Dual adhesive

Photo cure cement - Photo cure adhesive (otherwise wont bond)

Dual cement will fully cure with time

How do you conduct bonding of an indirect restoration?

Fill tooth and restoration with dual cement

Place tooth with pressure occlusally

Polymerise for 5 secs then remove excess cement

Cure each surface for 1 minute

What should we use to adjust occlusion and polish?

Occlusion - Fine grain turbine (yellow), Arkansas slow speed

Polish - Silicone tips (for porcelain)

What are the reccomendations within the first 24 hours of treatment?

Soft diet, avoid dyed food

Book 48hr revision (adjust occlusion)

Book 7-15 day revision (assess gingiva and eliminate cement traces)

Avoid usual mouthwashes

Warn about hypersensitivity (several weeks)

What should the patient do for maintenance?

Usual hygeine

Medium hard brush

What should the dentist do for maintenance?

3,6 and 12 month checkup (check tartar build up aswel)

Avoid ultrasonic instruments (can create fissures on ceramics)

Avoid abrasive polishing systems (remove glaze)

Polish marginal stains with silicon cups