Self adhesive and self etching are common dental terms that are often mixed up or misunderstood. This all started with self-etching (SE) adhesives. These SE products were intended to be bonding agents with water miscible solvents, as a dentin bonding procedure, and as an alternative to using phosphoric acid to etch, primarily dentin. Remember these products are called dentin bonding agents, not enamel bonding agents. SE bonding agents have a pH between 0 and 1.5. So far so good. The properties of dentin bonding agents that made them an alternative to phosphoric acid was that they had a pH low enough to etch dentin, and a few cases actually etch enamel.
Next came the self adhesive resin cements. These products do not have a low enough pH to effectively etch dentin, but have a pH usually between 1.5 and 3. As a consequence the self adhesive products are not meant to infer that either etching or bonding agents would not be a benefit to their use, only that they have a moderately acidic pH. It is in fact true that self adhesive cements have enough retention by themselves, not using a bonding agent or acid etching, to hold a crown in place. In this case retention is the key word, not shear bond strength (that testing is a horse of another color!)).
Self adhesive materials in fact perform even better, have greater retention, when used with a bonding agent to dentin. Self adhesive resin cements have proven themselves effective in crown retention now for many, many years. A little boasting here, I have probably the longest surviving crown cemented with a self adhesive cement. (call me for the details). Recall all the dis-belief, you know who you are, when these products were being introduced. Of course their testing was all wrong. The proof has now been shown to be in the pudding! And today we have many self adhesive resin cements on the market.
Thanks for reading along. Join in the banter. Next I will address what's going on with the self adhesive veneer cement products. By the way, check out Aura Veneer Cement and Aura VLC Cement, the first self adhesive VLC cement.
Thanks again. Jan.
Subscribe to:
Post Comments (Atom)
Thank you for this! It's good to have some clear explanation to common problems. Thanks again!
ReplyDeleteThank you!!
ReplyDeleteSo if there is a self adhensive resin cement product claims its PH value is high, close to neutral, should we still etch and bond before applying the cement?
ReplyDeleteThanks for sharing your your knowledge.
Granted, there is certainly confusion within the industry about what self-adhesive means. This is particularly true when self-adhesive is confused with self-etching. The original intent of self-adhesive was to provide a material that provides a relatively low pH. The incorporation of acidic monomers achieves greater retention than traditional monomers, such as, BIS-GMA and UDMA. In this approach, self-adhesive materials were never intended to have a pH low enough to achieve complete etching of enamel. The general concept however is to lower the pH using these monomers so that better adhesion will occur. A material who's pH is "close to neutral" would not achieve these results.
ReplyDelete