 IPS e.Max Press: Where Strength Marries Aesthetics
By Rob Maatta
IPS e.Max Press (lithium disilicate) has become one of the most popular restorations prescribed at Gold Dust. The versatility, strength and overall esthetics make it a dependable and go-to choice for discerning clinicians.
The versatility of the product is a luxury for the aesthetic ceramist because we no longer must face the challenge of matching multimedia cases. We can do a veneer next to a crown or bridge and feel confident that the final shade will be perfect. e.Max press has the capability of a three unit bridge, full coverage crowns, inlays, onlays and veneers. All of these restorations can be bonded or conventionally cemented.
The benefit of the e.Max press is that it is made of lithium disilicate and in the monolithic state has a flexural strength rating of 360-400 MPa. This is the strongest restoration tested to date.
When it comes to esthetics, e.Max press rivals nature. With the use of the correct ingot we can either draw color from the underlying tooth structure or block out a dark prep and build in the ideal esthetics with porcelain.
Ingot Selection
e.Max Press comes in 3 different opacities MO, LT, and HT.
MO: (medium opacity) this ingot is used primarily to block out very dark preps. It comes in four different ingot shades MO1, MO2, MO3 and MO4. The higher the number the more chroma. These restorations tend to be opaque if they are not cut back and layered with porcelain.
LT: (light translucency) mainly used in smile design cases that need some block out capability but nothing severe like a metal post or tetracycline staining. LT ingots come in all the corresponding Vita shades as well as the Ivoclar bleach shades.
HT: (High Translucency) the most popular ingot we use. Most of the coloring for the final shade comes from the prep itself, making it the most esthetic restoration available. It does come in all the corresponding Vita shades and Ivoclar bleach shades but it has no block out capability.
 Final Thoughts on Ingot Prescription
The comprehensive selection of ingots gives the ceramic team a wide variety of choices for an array of applications. With the introduction of the HT (high translucency) ingots, we have found that we now have another tool when it comes to relying on the underlying tooth structure for shade, and ultimately the most esthetic results. For those of you that are familiar with the IPS empress Esthetic ingots the HT ingot closely resembles the ETC0-ETC1 ingots in its translucency.
While we are aware that many clinicians like to prescribe a specific ingot in hopes of getting a specific result, we find there are many variables that control ingot selection during the fabrication process, including the thickness of restorations, underlying tooth structure, the preparation design and amount of reduction, and the final goals of the case. All of these factors are taken into consideration at time of press to adequately achieve the final result that has been prescribed. Working with this material, day in and day out, it makes the selection more predictable when you specifically prescribe a final shade and other characteristics and leave the ingot selection to your ceramist!
Contraindications
e.Max can be prescribed in almost every indication needed in dentistry with the exception of the following:- No molar pontics for bridges
- No bridges larger than 15mm between abutments
- Wing bridges where we can’t get a large enough connector
- Bridges larger than 65 mm (they won’t fit in the investment ring and the ingot size is limited)
We all know that the limiting factor in the strength of any restoration is the overlaying ceramic. In the case of the HT ingot the posterior restorations do not need to be layered with the addition of porcelain for increased esthetics, thus increasing the overall strength.
Additional resources:
 NYU performed a Mouth Motion Fatigue and Durability study which can be downloaded at http://www.ivoclarvivadent.us/emaxchangeseverything/downloads/view.php?fileid=1017.
For additional technical and clinical information, go to http://www.ivoclarvivadent.us/emaxchangeseverything/
Rob Maatta, co-owner and Gold Dust’s Aesthetic Team Leader |
