Who are inlays and onlays suitable for?
Inlays and onlays are particularly suitable for medium-sized to large tooth defects in the posterior region – that is, where the chewing surfaces are exposed to heavy loads. Typical indications are extensive caries damage or brittle old amalgam fillings that need replacing.
Compared with a simple composite filling, laboratory-made ceramic restorations offer clear advantages: they are more precise, more dimensionally stable and more durable. At the same time, the procedure is far gentler than fitting a full crown.
This is precisely the concept of minimally invasive tooth preservation: while a crown requires the entire tooth to be ground down all round, an inlay or onlay leaves the healthy, stable parts of the tooth completely untouched. Valuable natural tooth substance is preserved – a principle we follow consistently at moderndentistry.
What exactly is the difference between an inlay and an onlay?
An inlay, as the name suggests, is laid into the tooth: it sits entirely within the cusps and fills the cavity precisely, without touching the outer structures of the tooth.
An onlay goes one step further: it also covers at least one of the cusps when the defect is already larger and the stability of the tooth has to be secured.
Both variants are highly precise pieces made in a dental laboratory. They are individually adapted to the bite position and the anatomy of the tooth concerned. The result is a restoration that blends seamlessly into the natural dentition and supports exactly where support is needed.
Ceramic inlays versus conventional fillings
Conventional composite fillings and amalgam fillings have their limits – especially with larger defects. Composite can deform over time under chewing pressure; amalgam contains metal and copes poorly with temperature fluctuations.
A ceramic inlay, by contrast, offers a range of medical properties: all-ceramic material is highly resistant to chewing forces and abrasion, barely reacts to differences in temperature and is fully biocompatible – free of allergens and well tolerated by tissue. In addition, ceramic does not discolour over many years and retains its natural appearance.
A particular advantage lies in the adhesive fixation: modern adhesive technology bonds the inlay chemically to the tooth. This gap-free connection additionally stabilises the weakened tooth and protects it against bacteria penetrating – an important aspect of long-term tooth preservation.