Rahmat Hidayat

The combination of Biomimetic Restoration, onlay/overlay lithium disilicate, and Bio-Rim preservation is the gold standard for restoring endodontically treated teeth (ETT) in the modern Adhesive Dentistry Era.

Unlike traditional full crowns, which often require extensive preparation and removal of the Bio-Rim to achieve the "ferrule effect," a bonded onlay/overlay allows for the maximal retention of this essential structural ring.

This approach fundamentally shifts the focus from the old, invasive techniques that relied on mechanical retention (like posts and full crowns) to a conservative, adhesive philosophy that prioritizes reinforcing the natural tooth structure.

These partial-coverage restorations require less preparation than a full crown, allowing for maximum preservation of the Bio-Rim and healthy coronal walls. They are used to cover and protect cusps that have been weakened by the endodontic access and prior restorations.

The Bio-Rim is a critical concept in biomimetic dentistry. It refers to the 2-3 mm of remaining healthy tooth structure, including the enamel, the dentin-enamel junction (DEJ), and superficial dentin, located coronally (above) the cemento-enamel junction (CEJ) or bone crest.

Preservation of this zone is paramount because it is the natural load-bearing area (often called the "Compression Dome"). This ring of healthy tooth structure acts to dissipate and distribute occlusal forces, protecting the remaining tooth and root from fracture.

Lithium Disilicate ceramic is chosen for its high strength, fracture toughness, and excellent aesthetics. Crucially, it is a bondable ceramic, meaning its surface can be etched (with hydrofluoric acid) and silanated to achieve a strong, durable, micromechanical bond to the resin cement then to create a "monoblock" effect, which helps to increase the tooth's resistance to fracture, unlike traditional restorations that rely on mechanical retention (like full crowns).

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