Adhesion in dentistry

🤔 Sometimes we are asked: "What are the differences between restorations made of zirconia oxide, metal-ceramics, and non-framework ceramics (veneers, inlays, overlays)?"

🔹 Before answering this question, we need to understand the concept of "adhesion in dentistry."

🎯 Adhesion (from Latin, meaning "sticking") is the force that connects two different materials brought into close contact. Adhesion can be mechanical, chemical, and other types. We are interested in chemical adhesion.

💪🏼 Here, the important concept of "adhesive strength" comes into play. — Adhesive strength is measured in pascals — kPa, MPa, GPa. The higher this value, the stronger the bond between the two objects (in dentistry, this refers to the "bonding" between two surfaces — tooth tissues and any restoration, whether it is a filling, crown, veneer, inlay, overlay, pin, etc.). 🔹 Here’s an important point — adhesive strength to different tooth tissues varies, and different materials either have chemical adhesion properties or do not. We will discuss materials next time, but today we will talk about adhesion to different tooth tissues.

🔹 In fact, the choice is not extensive; we can talk about either enamel, which varies in thickness from 0.5 to 2 mm in different parts of the tooth, or dentin, which makes up the remaining volume of the tooth.

☝🏼 Adhesion to enamel, depending on the adhesive agent, is up to 30 MPa, while adhesion to dentin is around 10-15 MPa, which is nearly twice as low. 🔹 In reality, the topic of adhesion is very broad and covered in courses for dentists, so there are many subtleties and nuances. ✅ But the main point to understand is that adhesion to enamel and dentin is different.

— Since enamel covers the entire tooth and is very thin, when dealing with heavily damaged teeth, we often deal with dentin for more than 50% of the surface. Therefore, the appropriate material should be chosen for each clinical case. Wearing sandals in winter and winter boots in summer would be inappropriate. But if done the other way around, everything will fall into place. 👌

💎 Therefore, this should be considered when choosing methods for tooth restoration.