Inlays and onlays are indirect dental restorations (ceramic restorations) fabricated in a laboratory to treat moderately decayed or fractured teeth.

  • Inlays: Fit neatly within the cusps of the tooth.
  • Onlays: Cover one or more cusps of the tooth (often referred to as partial dental crowns)

Pros:

  • Maximum Preservation: Unlike a crown, which requires shaving down the entire tooth, an Onlay allows the dentist to keep up to 70% more of your natural healthy enamel and dentin.
  • Structural Strength: Because they are “bonded” rather than just packed into a hole, they can increase a tooth’s strength by up to 75%.
  • Superior Fit: Created using CAD/CAM digital scans, these restorations fit your tooth with micron-level precision, leaving almost no room for bacteria to seep in.
  • Aesthetics: Made from advanced ceramics (like E-max), they are virtually indistinguishable from natural teeth and do not stain over time like composite fillings.

Cons:

  • Higher Initial Cost: They are significantly more expensive than a standard filling because they require laboratory fabrication or high-tech in-office milling machines.
  • Complex Procedure: The bonding process is extremely “technique-sensitive.” If the moisture is not controlled perfectly during the seat, the bond may fail.
  • Time: Unless your clinic offers Same-Day CAD/CAM, you will typically need two appointments and a temporary filling in between.

Issues Treated by Inlays and Onlays

Inlays and Onlays are specifically designed for teeth that have moderate damage but still possess enough healthy structure to avoid a full crown.

  • Large Cavities: When a cavity is so wide that a standard composite filling would weaken the remaining tooth walls or shrink over time.
  • Fractured or Chipped Teeth: To restore teeth that have lost a significant piece of their structure (especially the biting “cusps”) but the root and base remain strong.
  • Replacement of Old Amalgam Fillings: Large silver (amalgam) fillings often cause “stress fractures” in teeth over decades. Inlays/Onlays are used to replace these and “bond” the tooth back together.
  • Moderate Wear and Tear: For patients with erosion or abrasion that hasn’t yet reached the stage of requiring full-mouth reconstruction.