As dentists, we see many patients with worn incisal edges. Before restoring these teeth, we need to understand the type or pattern of the tooth wear. Pathway, edge-to-edge or crossovers are the three main forms and any single one or even all may be present.
What makes a restored edge-to-edge wear case successful? The answer is the “sweet spot.” If we don't create a definitive flat spot on which the patient may function, they will undoubtedly fracture our new porcelain restoration.
Getting patients engaged in the restorative process is very challenging. How can we help patients understand the importance of the sweet spot?
The following is a good visual for helping patients “see” what we're talking about, relative to function on the edges of anterior teeth. Place two rubber balls between your first finger and thumb. When you squeeze your fingers together they fly away and bounce. It's almost impossible to maintain pressure against two round surfaces (round incisal edges). There is no stability.
However, what if they each had a small flat surface (flat incisal edges)? When pressure is applied from the fingers, an unlimited amount of force could be used and they won't fly away. This is complete stability.
This is precisely what we are attempting to achieve with our porcelain restorations. Our goal is to restore worn edges to esthetic and functional harmony. By providing a small or limited flat surface (sweet spot), we allow patients freedom to move and can more predictably achieve long-term results.
Jeffrey T. Bonk DDS, Spear Visiting Faculty. jeffreybonkdds.com