Dentistry continues to evolve on multiple levels, with changes in indirect restorative materials, the need for reproducible results, and implementation of cementation.
Cementation is highly influenced by variabilities in tooth preparation and length, enamel and dentin substrates, restorative properties, and surface adhesion, as well as curing light transmission through the materials, which is compromised with metal and zirconia.
Many dentists around the world have this “wish list” of qualities:
- Reliable: optimal performance for retentive and nonretentive preparations
- Universal: excellent bond strength to tooth and all substrates, including zirconia, metal alloys, glass ceramics, and hybrid ceramics
- Technique insensitive: exceptional self-curing ability and moisture tolerance for peace of mind
- Esthetic: invisible, wear-resistant margins for esthetic outcomes
- Simple: reduced inventory, reproducible results, and optimized workflow
Fortunately, GC America recently developed G-CEM ONE™—a dual-cure, self-adhesive resin cement with high adhesive bond strength, which can be used for extended indications when using its optional Adhesive Enhancing Primer (AEP). The objective of this system is to provide dentists with 1 simple solution for all day-to-day procedures.
The beauty of AEP is that it can be applied and dried without light curing. With GC America’s Touch Cure technology, the accelerator in the AEP reacts with the initiator in the cement during crown luting, which enhances curing capacity independent of light. It not only overcomes the light transmission issue in all restorations, but it also reliably overcomes challenging situations such as:
- Renewal of an old crown
- Limited height of abutment
- Low retentive preparations for onlays, inlays, and veneers
- Saliva contamination
Fifteen members of Catapult Education were asked to evaluate G-CEM ONE, which is built on tried-and-true existing technology. The evaluators typically use a resin-modified glass ionomer or other resin cement for most of their cementations. In terms of finding a supreme cement, the evaluators were overwhelmingly looking for one that could be used on all substrates and would be easy to handle and clean up. Surprisingly, although many thought bond strength was important, it didn’t seem as important as the handling and cleanup of the material.
Most of the evaluators cemented at least 5 restorations with the material and, to this date, this evaluator has cemented more than 40. The most common restoration cemented was hybrid ceramic inlays and onlays, followed by porcelain-fused-to-metal bridges, and then lithium disilicate crowns and zirconia crowns. The following is what the group found:
- More than 80% of the evaluators noted that they used the adhesive primer most of the time, with one evaluator stating, “If I could add more bond strength, why wouldn’t I use it?”
- Handling was not an issue for anyone, with nearly 99% of the evaluators liking how G-CEM ONE handled. Evaluators noted that the syringe size and extrusion force of the material were also very good.
- Cleanup methods varied between evaluators; 60% of the evaluators tack-cured the material and then cleaned it up, and the remainder waited for it to partially set and cleaned it up easily when it was rubbery or used a brush to wipe away the cement when wet. More than 90% felt cement removal was easy.
- More than 80% said they would purchase the G-CEM ONE, and 100% said they would recommend this to a colleague.
Overall, the group of 15 doctors were very impressed with many of the added features. This is a strong evaluation, especially in a product category for which every clinician is looking for a more idyllic solution.
Case No. 1
A vacationing patient from out of state broke her 20-year-old ceramic crown on tooth No. 8 while chewing. Although the tooth had remaining tooth structure to create a ferrule, the preexisting post had fractured and would ideally be removed by an endodontist prior to replacing the crown.
Fortunately, the crown could be accurately recemented with G-CEM ONE using AEP, and the missing porcelain could be replaced using G-ænial™ Universal Injectable
composite (GC America), so the patient could resume her vacation with a big smile and get more ideal care when time and convenience were optimal.
Figure 1.
Patient fractured tooth No. 8 because of a broken post and malocclusion.
Figure 2.
Despite fractured facial porcelain, the preexisting crown fit interproximally and lingually.
Figure 3.
After recementation with G-CEM ONE using the Adhesive Enhancing Primer, the missing porcelain was replaced using G-ænial composite to match the porcelain shade and block out underlying tooth structure.
Figure 4.
The patient was ecstatic to smile again and proceed with her travel plans.
Case No. 2
A 40-year-old patient with heavy bruxing needed a preexisting crown replaced on an endodontic tooth that had limited occlusal space. After her tooth was rebuilt, a zirconia crown was treated by air abrading internally and painted with an methacryloyloxydecyl dihydrogen phosphate (MDP) product. After carefully painting the short prep with AEP, the crown was easily cemented and cleaned up with G-CEM ONE.
Figure 1.
This patient’s tooth fractured because of redecay, lack of adequate post reinforcement, and ferrule effect.
Figure 2.
The zirconia crown is initially treated with 50-micron aluminum oxide.
Figure 3.
The predictability of cement adhesion to the zirconia is enhanced by applying a primer containing MDP.
Figure 4.
Short preparation bond strength is overcome using an application of AEP for 10 seconds and gently drying it for 5 seconds.
Figure 5.
G-CEM ONE is carefully placed on the intaglio of the crown restoration so that minimal cement extrudes upon seating and easy cleanup can take place after 1- to 2-second tack cure.
Figure 6.
Current successful postoperative picture will be esthetically improved with future tooth whitening and replacing the crown on the first bicuspid.
Summary
GC America has created a reliable, efficient, and easy-to-implement cementation product that could be considered a “Swiss Army knife” for handling multiple types of indirect restorations that can be used for retentive and nonretentive preparations. Even better, when isolation is a challenge, research and our study have proven that G-CEM ONE can overcome saliva contamination, assuming strict adherence to manufacturer instructions and using AEP.
Overall, GC America has produced a true winner.
Reference
1. Ishii R, Yokoyama M, Tamura T, Takamizawa T, Miyazaki M. Shear bond strength of resin cements to saliva contaminated dentin. 2020. 153rd Meeting of the Japanese Society of Conservative Dentistry. P24. (available only in Japanese)
Download Issue: Dental Products Report February 2022
