Advances in dentistry have dramatically improved dental procedures, the quality of dental care, and the clinical dental experience and outcomes for patients. One example of this is in terms of dental bonding.
Dental adhesive technology has changed enormously since it was first conceived of in the 1950s, and the progress made in this area has greatly impacted general dentistry and restorative dentistry by helping preserve natural teeth while also improving the strength of bonds and minimising treatment complexity. A gold standard product for achieving all of these is Scotchbond Universal from 3M.
What Are Dental Adhesives?
Working by exploiting both mechanical and chemical interactions, dental adhesives or bonding agents bond or “cement” restorative materials (e.g. composite fillings, veneers, crowns, etc) to tooth structures. They must be able to effectively bond to both tooth enamel as well as dentine, which is the tissue under the enamel that forms the main body of the tooth.
The benefits of using modern materials such as Scotchbond Universal dental adhesive include faster procedures, stronger and longer-lasting restorations, natural tooth preservation, and revolutionary inbuilt features such as remineralising and antibacterial properties.
The quality of bond achieved by dental adhesives is most commonly evaluated using bond strength testing. This is measured in megapascals (MPa), and it is defined as the load required to break a bond in terms of the area of the bonding surface.
How Has Dental Bonding Technology Changed?
We are now in the eighth generation of dental adhesive technology, with a journey lasting over fifty years to date.
1st Generation adhesives:These first dental adhesives emerged in the 1960s. They focused on bonding to enamel, were very weak, and had limited success, with an adhesion power/bond strength of only 1-3 MPa.
The next few generations in bonding technology built on the first, including the introduction of dentine conditioning and priming. Multiple clinical steps were required to achieve this.
4th Generation adhesive systems represented a significant improvement and leap in technology. With an unprecedented bond strength of 25 MPa, they set a new benchmark in terms of reliable bonding to both enamel and dentine. These systems required three clinical steps (etching, priming, and adhesion), making them time-consuming, and their key innovation was the total-etch technique.
The 5th Generation saw a two-step etch-and-rinse strategy, with primer and adhesive combined. 6th Generationadhesives that were faster with two clinical steps used self-etch technology, combining etching and priming, followed by adhesive. These had a bond strength of 20 MPa. 7th-Generation adhesives were all-in-one systems offering up to 25 MPa bond strength.
We are now into the 8th Generation of Universal Adhesives, and these enhanced molecular bonding systems require just one clinical step and deliver over 30 MPa in adhesive power. They enable more flexibility and are designed for use on enamel, dentine, ceramics, metal, and more.
Contemporary Dental Bonding Systems
Three main types of dental bonding systems are used in dentistry today.
- Etch-and-rinse systems: these systems use phosphoric acid to create microscopic holes in the bonding surface. This enables the resin to deeply penetrate the surface and is best used for bonding strongly to enamel.
- Self-etch systems: these adhesives are ideal for dentine bonding. They use acidic chemicals to etch and prime the tooth’s surface in a single step, forming a chemical bond with calcium in the tooth.
- Universal adhesive systems: these revolutionary systems are compatible with several etching techniques and both enamel and dentinee, as well as materials from metal to ceramic and many more.
Conclusion
Modern dental adhesive technology enables robust, durable bonds between tooth structures and restorative materials. They also allow existing tooth structures to be preserved, reducing the need for treatments such as root canal therapy. The availability of products like Scotchbond has transformed restorative dentistry and plays a key role in the success and longevity of fillings, crowns, veneers, and other dental restoration types.