Indirect restorations
Crowns, onlays and inlays require sound indications, ferrule or remaining tooth assessment, preparation geometry and a suitable luting strategy.
Understand
Indirect restorations need retention or bonding, adequate material thickness and a tooth that can be restored predictably. Full coverage sacrifices more tissue than an onlay.
Assess
Assess ferrule, cracks, endodontic status, margin position, occlusion and hygiene access. The chosen material changes reduction and luting requirements.
Apply
Plan preparation from the final restoration, protect pulp and provisionalise effectively. Review whether an extraction or simpler restoration offers a better long-term outcome.
Key distinctions
Ferrule is the sound tooth structure engaged by a crown above the finish line, not merely a post in a root. A post retains a core but does not strengthen a weakened tooth by itself. Deep subgingival margins, cracks or poor periodontal support may limit restorability even when an impression can technically be made.
Think through a case
A cracked endodontically treated premolar has little coronal tissue. Compare onlay, crown and extraction against ferrule and remaining sound tooth, not the presence of root filling alone.
The distinction to remember
Do not prepare a full crown by default when a more conservative design can protect the tooth, or when the prognosis is already poor.
Test your recall
Why is an onlay sometimes preferable to a full crown?
Show answer
It can protect a weakened cusp while conserving more tooth tissue.