Clinicians are familiar with the development of a white line at the interface between composite and tooth structure. Often, the restoration looks great when initially placed, and then a white line appears after finishing.
It is mainly a mix of broken-down enamel and broken-down composite. These white lines are often the result of enamel cracks which trap polishing debris at the marginal area. Because enamel is very weak in tensile strength, these fractures in the enamel could be the result of several factors:
Also, because the composite resin is in a thinner layer at the margin, the restorative material may break down more easily from occlusal forces. The white line will eventually turn brown over time and will encourage caries to develop.
One way to avoid this phenomenon is to fill up the micro gap with an unfilled penetrating sealer. The sealer will add longevity to the restoration and it will also reduce leakage and sensitivity.
A common misbelief is that the sealer wears off over time. It will eventually wear off on the buccal surface from toothbrush abrasion, chewing, and other functions. However, the marginal gap between the tooth and the restorative material is only 20 to 60 microns, which is less than the size of a human hair. If compared to a bristle of a toothbrush (200 to 300 microns), one can clearly understand that minimal surface is exposed and therefore this area is unlikely to wear off.
After polishing and occlusal adjustment, etch all composite surfaces to be sealed and adjacent tooth surfaces for 20 seconds. Ultra-Etch™35% phosphoric acid is easy to apply thanks to its ideal viscosity.
Note: Since polishing may open micro gaps, we recommend sealing after polishing.
How does PermaSeal sealer compare with other composite sealers on the market? Many sealers come in a bottle, which tends to waste material during application. PermaSeal composite sealer offers simple syringe delivery and the Black Micro™ FX™ tip gives precise and efficient placement. You only need a drop or two per application! Some brands of sealers are a filled resin. While filled resin may be stronger, it does not penetrate into the composite. PermaSeal composite sealer has the lowest viscosity when compared to other sealers on the market, plus an excellent wettability. It flows like water so that any micro gap is completely filled.
The use of a bonding agent is not recommended when using a composite sealer. Many bonding agents have a yellowish color which may change the esthetic aspect of your restoration. Some bonding agent may be filled as well.
PermaSeal sealer provides a great finish to any type of composite restoration: direct, indirect, anterior, posterior, and provisional. It works perfectly with the Uveneer™ direct composite template technique too.
PermaSeal composite sealer can also be used for the final glaze-type finish of resin provisionals. In order to achieve that, cover PermaSeal sealer with DeOx™ oxygen barrier solution prior to light curing. It also bonds well to composite-type provisional restorations and can be used to revitalize old composite restorations.