How to complete partial coverage restorations with the 3M™ ESPE™ Trifecta System [VIDEO]

When placing partial coverage restorations, marginal integrity and esthetics are logical concerns.

Dentists with in-office milling systems may have a heightened awareness of these issues, as they can see the impacts of the edge quality of their materials at each step of the way. While some chairside blocks can be brittle, resulting in minute chipping at the margins of a restoration, a non-brittle material makes the process much smoother, with a restoration that almost disappears into the margins.

After almost 10 years of using a CEREC machine in my office, I have recently come across a combination of materials that is now my first choice for partial coverage restorations: 3M™ ESPE™ Lava™ Ultimate Restorative, 3M™ ESPE™ Scotchbond™ Universal Adhesive and 3M™ ESPE™ RelyX™ Ultimate Adhesive Resin Cement.

This combination of products, known as 3M™ ESPE™ Trifecta System, not only gives CAD/CAM dentists a strong, easy-to-mill chairside block, but also tools for adhesion and cementation that contribute greatly to the efficiency of a procedure.

Block, Adhesive and Cement Working Together

Lava Ultimate restorative is a unique block material that is categorized as a “resin nano ceramic.” This material is both strong and resilient, and it is designed for fast, easy milling and easy adjustments. It can even be repaired with composite, making it very versatile for teeth that might need additional work in the future.

It is indicated for crowns, inlays, onlays and veneers, and as noted, I particularly prefer it for partial coverage restorations. When used for inlays, onlays or three-quarter crowns, the material’s ability to mill with no chipping helps it blend seamlessly into margins.

Additionally, no firing is required for this material and it takes only a few minutes to polish, adding to the efficiency of a chairside milling system.

Efficiency is also a key feature of Scotchbond Universal adhesive. This adhesive bonds methacrylate-based restoratives, cement and sealant materials to dentin, enamel and glass ionomer, as well as indirect restorative substrates like metals, glass ceramics, alumina and zirconia, without an extra primer step. It can be used in total-etch, self-etch or selective-etch modes, providing reliable strength and virtually no postoperative sensitivity.

The simple technique of Scotchbond Universal adhesive is made even better by combining it with RelyX Ultimate cement. The cement is made with an integrated dark cure activator for Scotchbond Universal adhesive, so when the two products are used together there is no need for a separate activator.

This can give dentists extra peace of mind in cases where a restoration is hard to reach with a curing light or they are worried about the depth of cure. The cement also cleans up easily, whether it is still in its liquid form or after tack curing. I personally prefer to clean away excess cement right away without tack curing, and have found this gives me great margins and adaptation.

With RelyX Ultimate cement, I can do this easily and achieve a great bond. The cement is ideal for CAD/CAM and glass ceramic restorations, making it an easy choice to use in combination with Lava Ultimate restorative.

The case shown here will illustrate the use of these products to create a seamless onlay.

Step 1

A patient in her 50s presented complaining of sensitivity on a 20+-year-old amalgam restoration on tooth No. 20. Examination revealed a crack through the enamel on the lingual cusp of the tooth.

Step 2

The patient consented to removal of the amalgam and treatment with a Lava Ultimate restorative onlay, which would cover the lingual cusp and reduce the sensitivity.

Step 3

The old amalgam was removed and the tooth was prepared for an onlay. The CEREC Omnicam was used to capture a digital scan of the tooth, and the onlay was milled with a Lava Ultimate restorative block.

Step 4

The sprue was removed from the block and it was tried in the mouth to confirm a good fit. Following this, a Danville MicroEtcher was used to sandblast the inside of the onlay, after which it was rinsed and dried.

Step 5

Scotchbond Universal adhesive was scrubbed for 20 seconds into the bonding surface of the restoration and then air thinned until the solvent was evaporated and the adhesive no longer moved.

Step 6

The adhesive was also applied to the prepared tooth and scrubbed in for 20 seconds. The material on the tooth was also air-blown until it no longer moved and then light cured for 10 seconds.

Step 7

RelyX Ultimate cement was applied to the preparation, and the onlay was then seated in place. Excess cement was immediately cleaned away and the restoration was light cured for 20 seconds.

Step 8

A fluted finishing bur was then used to clean residual cement away from the edges. Polishing was performed with a Brasseler point, progressing to a final polish with Diamond Twist SCO polishing paste and a micro-cloth disc. The case was completed in approximately one hour, and the final result was a much more esthetic restoration with indetectable margins.

Conclusion

The combination of the esthetic block material, adhesive and cement used here helped create a restoration that is nearly invisible at the margins, with a strong bond that will keep it in service for the long term. With a system of products that is designed to work together, dentists can enjoy a process with fewer steps while still feeling assured they are delivering great care.