When a Filling Isn't Enough – The Benefits of Inlays and Onlays
There comes a point in the progression of dental decay or damage where a direct filling is no longer the optimal solution — but a full crown is not yet warranted. In this intermediate zone, inlays and onlays offer a superior alternative that preserves more tooth structure and delivers better long-term outcomes.
The Problem with Large Fillings
When a cavity is large, a direct composite or amalgam filling faces inherent limitations:
- Polymerisation shrinkage: composite resin contracts slightly as it cures, creating marginal gaps that allow microleakage and secondary decay
- Reduced strength: a large filling occupies a significant proportion of the tooth, leaving thin walls of remaining tooth structure that are vulnerable to fracture
- Difficult contour: achieving ideal shape, contact points, and occlusion with a hand-built direct filling in a large space is technically demanding and rarely as precise as a laboratory restoration
What Makes Inlays and Onlays Superior?
An inlay or onlay is fabricated outside the mouth in a dental laboratory under ideal conditions. The advantages include:
Precision fit: Laboratory-fabricated restorations can be shaped and polished to a precision that cannot be achieved in the mouth.
Strength: Ceramic inlays and onlays are significantly stronger than composite, distributing biting forces more effectively.
Longevity: Well-designed ceramic inlays and onlays routinely last 15–25 years — substantially longer than large composite fillings.
Preservation: An inlay removes only the damaged tissue; a crown would require removal of healthy tooth structure on all sides. Preservation of healthy tooth is always the priority.
The Inlay and Onlay Process
At Smilecraft, the process involves digital scanning of the prepared tooth, CAD design and laboratory fabrication, and a fitting appointment for final placement. Using digital impressions and modern ceramic materials, we can deliver restorations of exceptional quality in minimal appointments.
