Inspired by the newest article from Drs Alleman et al. in Inside Dentistry, here is an obscenely simplified and quick intro to the concept of Decoupling With Time.
What is Decoupling With Time?
Refers to the process of separating (or decoupling) the bonding steps of different layers of the restoration, specifically dentin and enamel layers (1).
Decoupling the bonding of dentin and enamel allows the dentin bond to fully mature and become as strong if not stronger than the bond to enamel. This is related to the “Hierarchy of Bondability” concept which says that “when polymerizing, composite shrinks toward the wall or walls of the preparation that are the most mineralized and dry” (1).
How do you decouple? And how much time do you need?
After immediate dentin sealing and resin coat steps, a decoupling time of at least 5 minutes is recommended to allow the dentin hybrid bond layer to mature (2). During this time you don’t light cure anymore, you don’t add anymore increments, you just let it sit.
Decouple before placing any increments thicker than 1.5mm. At least 5 minutes is indicated because it takes that time for “the free radical polymerization that is forming the hybrid layer in dentin” to complete “80-90% of its potential monomer conversion” (1).
Check out the August 2021 edition of Inside Dentistry for more Biomimetic content from Drs. Schiffenhaus, Alleman, and Nejad.
Click on the link below for the full article and links to references!
General Dentist. Author at The Tooth Bank and create content for our social media with a focus on providing information for new dentists..