We all strive to make our provisionals fit as well as we can. Improved fit of our provisional restorations reduces tooth sensitivity and increases tissue health, thereby leading to a more efficient delivery of the definitive restoration. Today, the most common material used to fabricate provisional restorations is a Bis-acryl composite. If you use this type of material, one easy step to help improve the marginal fit of your provisional restorations is to physically remove the air-inhibited layer that develops on the "internal" of the provisional.

For years my protocol for trimming a provisional restoration has been to first clean the provisional in alcohol prior to starting the adjustment process. This helps to remove the air-inhibited layer and make the adjustment process more efficient without clogging up the bur. After completing the adjustment of the provisional with burs and disks, I would air abrade the internal of the provisional with a sandblaster.

This process helped me achieve a very nice marginal fit. However, I believe the fit of my provisionals is now even better. What I have started to do to help improve the fit of my provisional restorations is to manually scrape the internal of the provisional with a hand instrument prior to air abrasion.

As you can see by the photo, this additional step removed a fairly significant amount of material that is not fully cured and isn't removed by air abrasion. Removing this material with a hand instrument enables a more "passive" and complete seat of the provisional restoration on the tooth, thereby leading to a better fit. Try this on your next provisional restoration and you too will see how it will help improve the marginal fit.