Dentists were introduced to a new development in restorative dentistry—methacrylate-functionalized calcium phosphate (MCP) technology—in January 2022. MCP is significant because it is a biointeractive molecule that can help teeth remineralize and recover from damage caused by dental caries. It can also act as a precursor for nucleation sites for apatite formation at the material-tooth interface. MCP’s versatility is also significant—it can be incorporated into a wide range of dental materials. MCP technology was patented by Pulpdent Corporation and given the trade name Crysta. It is currently available in two products—a universal composite called Activa Presto and a liner called Lime-Lite Enhanced.
MCP enables the single-syringe light-cured application of a biointeractive material. It has been shown to create an apatite-like interface when in contact with saliva, helping occlude the material-tooth interface against bacterial ingress. The incorporation of MCP in a liner enables a simple, direct application for deeper preparations. The liner adheres to dentin and easily bonds to both traditional and biointeractive restorative materials. When used in conjunction with MCP-containing composites, dentists have the ability to create ion-releasing restorations that may create a consistent seal throughout the entire cavity preparation.
Also by John Comisi, DDS
When dentists place bonded restorations, acidic materials are used that allow the formation of a hybrid layer. This process of creating a “tissue engineered” hybrid layer interface is, as we know, quite complex. Many factors can interfere with the formation of good initial and long-term seals. For example, the acids present in etchants and bonding agents release fossilized enzymes in dentin (MMPs) that degrade the hybrid layer. Trapped water in the dentinal tubules present another problem by releasing various proteolytic enzymes from the dentin, which attach to the hybrid layer.
This ultimately changes the initial hydrophobic layer into a hydrophilic layer, and over time creates a “failure from within” for the restoration. Scientists have been working to solve this problem and prevent this internal degradation. MCP-containing materials may be a major step forward in this area.
Numerous advantages of MCP
The action of MCP is not diminished by the application of a bonding agent. In fact, bonding is an essential component in the restoration process, providing the initial bond strength for every restorative material. The key point to understand, as described above, is that as the proteolytic enzyme activity of the restored dentin comes into play, it breaks down the bond and makes the bond more hydrophilic. But the ion release from MCP could permeate this hydrophilic-challenged bond and inhibit further proteolytic degradation and help maintain bond strength over time.
The biointeractive action of MCP technology also can help seal gaps from the ever-present polymerization shrinkage of methacrylate materials. All methacrylate materials shrink; this is a scientific fact and a primary cause of secondary decay around composite restorations. The ion release from MCP-containing products may remineralize dentin and form a seal over time to help protect the tooth from bacterial incursion that leads to secondary decay.
From a clinical standpoint, products containing MCP are leading the way in the effort to reduce marginal leakage, prevent enzymatic proteolytic breakdown of the hybrid layer, and provide nucleation sites for remineralization of damaged tooth structure and the restorative-tooth interface. We have been using MCP-containing products at my university for quite some time now. Because they are easy to place, apply, and use, practitioners favor using them. In my opinion, MCP-containing materials belong in every dental office and can be used for multiple applications. Investigate them for yourself and see how they can work in your practice.
Editor's note: This article appeared in the February 2022 print edition of Dental Economics.