Over the past several years, there has been widespread adoption of lithium disilicate based restorations (e.g. IPS e.max®*) by the restorative dental community. Previously, restorative dentists were limited in their material selection depending on the need for strength or esthetics. Now, this proven material allows clinicians to address most situations without sacrificing strength or beauty.
Over the past several years, there has been widespread adoption of lithium disilicate based restorations (e.g. IPS e.max®*) by the restorative dental community.
Previously, restorative dentists were limited in their material selection depending on the need for strength or esthetics. Now, this proven material allows clinicians to address most situations without sacrificing strength or beauty.
However, this unified material approach often requires the use of different bonding or cementation techniques depending on the location, opacity and type of prosthesis being
BISCO’s new bonding system, eCEMENT™, meets the various delivery requirements in a single, simplified kit that incorporates both light cure and dual cure resin cements. This kit was created specifically for lithium disilicate and most other all-ceramic restorations.
In addition to the two different cements, the kit includes a combination of innovative and proven products to simplify the adhesive protocol: etch for both the tooth and ceramic, porcelain primer and a bonding agent. In the following case, the dual cure cement was chosen because of the thickness and low translucency of the finished restoration.
The patient presented with tooth No. 12, which recently had been treated with root canal therapy and a bonded post and core. Restoring premolars that have had root canal therapy can be challenging because of the minimal residual dentinal wall thickness, as well as their visibility in the esthetic zone.
Increasing the difficulty, the premolar exhibited a short clinical crown height, and a widened mesiodistal space because tooth No. 11 was rotated.
Being mindful of biologic width requirements, the tooth was prepared with a subgingival margin to allow enough room to create natural emergence contours, especially on the mesial and distal surfaces. A shallow margin would not have allowed an esthetic outcome, while maintaining a cleansable proximal profile.
At delivery, the provisional crown was removed, and the polycarboxylate temporary cement was removed from the tooth surface with an air driven sonic scaler. The lithium disilicate crown was tried in and the marginal fit, proximal contacts, and occlusion were verified.
The intaglio of the restoration was etched with the eCEMENT kit’s porcelain etchant for 25 seconds, then rinsed and dried. The included porcelain primer was then brushed inside the crown and left for 30 seconds, then dried.
Two coats of All-Bond Universal® from BISCO Dental Products, a single bottle, self-etching adhesive were applied to the tooth according to the manufacturer’s instructions, and light cured for 10 seconds. The film thickness of the adhesive is less than 10 microns and will not interfere with seating of the restoration
After bleeding the automix syringe, the crown was filled with dual-cured eCEMENT. The crown was fully seated onto the prepared tooth. The cement was tack cured for three seconds facially and palatally, and the excess was easily removed with an explorer.
After thoroughly removing any subgingival marginal cement, the facial, occlusal and palatal surfaces were cured for 20 seconds each with a high-output LED curing light. While this step is optional, it is my habit to post-cure dual-cured adhesive cements to inactivate any light sensitive molecules.
The final result fulfilled the unique space, height and color requirements of this case, and the patient was very satisfied with the outcome. The occlusion and contacts were rechecked, and the patient was dismissed.
Compared to alternative bonding and cementation systems, the eCEMENT™ system was uniquely suited for this particular case, where the margins were placed in a significantly subgingival position to idealize the contours, strength and retention.
To control bleeding during delivery of a fixed prosthesis with subgingival margins, several criteria must be met, including a properly fabricated provisional and gentle but complete removal of all provisional cement. Even then, it can be a challenge to keep the site free of blood when etchants and bonding agents come into contact with the gingiva.
In this case, the materials in the eCEMENT kit did not cause any issues with bleeding. In
fact, the only blood that was encountered was during the final cleanup of the subgingival margins.
From an inventory point of view, stocking and becoming familiar with a single bonding system maximizes efficiency while minimizing errors and material waste. In doing so, delivery times and esthetic outcomes approach an optimal level of predictability.
In summary, the eCEMENT kit provides a comprehensive bonding solution to every lithium disilicate restorative situation, including veneers, inlays, onlays, crowns, fixed prostheses and CAD/CAM fabricated restorations. In doing so, it allows the unified approach of this versatile material to reach its full potential in an efficient and predictable manner.