Remaking E.max Crowns

The full name of E.max crowns is cast ceramic teeth, we often called it an all-ceramic restoration. It is made of a new ceramic material that can be cast, it just appeared in recent years. The tooth crowns can be divided into metal casting crowns, porcelain fused to metal crowns and all-ceramic crowns. The cast ceramic crown is the most expensive tooth crown.

This client started working with us in May 2019. Yet, he had been working for a long with another dental lab in China, so he didn’t give us all his work until September 2019. One day, he sent us an E.max case that required a remake. It was a very urgent case. He asked us to make it right as soon as possible. Until this time did we notice that this client gradually gave more work to us, including remake cases from other labs.

Actually, it would be better to send back remake cases to the labs that made the cases, because they can redo cases for free. However, the lab in question had quality issues several times, and the client couldn’t afford any more delays. The E.max case had to be delivered as soon as possible.

In the last cooperations, our quality and delivery time were appreciated by the client, so we received this remake case at the time. Although we were not willing to see any remakes from our clients, we still felt happy, because it clearly showed that our client had trust in us.

1. Examine requirements

We directly communicated with the customer and rushed the work. As shown on the lab sheet, our customer’s request was to cover the lingual to the margin. After having the stone models, we could see the lingual side was obviously prepared. However, the actual E.max crown he had received was way too short on the lingual edge, a fatal problem that made the crown unusable.

2. Comparison

The crown on the left picture below is from the other lab (the crown on the right picture below is from us). The lingual side is obviously too short. We think there are at least two reasons for this problem.

1. Poor technique. Technicians from the lab could not read margins clearly. Their lack of experience leads to this poor dental case. It seems that the case comes from the hands of apprentices.
2. Poor quality control. Good quality control teams will find this problem and fix it directly in the lab. In Robust dental, we never let this kind of work to the hands of customers.

3. Our stone models

Please check the following images. The left one is the study model, while the right one is the working model we have made. Looking at the working model, the margins are very clear. Our technicians can read margins very accurately, which lays a good groundwork for a nice crown. In Robust dental, even if our technicians are unsure of the margins, they will have the marketing staff talk to clients, in order to avoid mistakes.

4. Our finished work

Our technicians took 3 days to finish the case, which totally resolved the margin problem. As shown in the following pictures, our E.max crown is good at all angles and the fittings are perfect, either on the study module or on the working module.

In addition, we have bettered the occlusional form, which gives the entire crown a more three-dimensional look. We also apply a light stain on the coolusion. Even the shade appears to be better because of the authentic material that we have used. All these details make our crown look more natural.

5. Our suggestion for outsourcing

The old E.max crown is sub-standard in terms of various details such as margins, shades, and aesthetics. In dentistry, many novice customers are attracted to the so-called low prices, but these low-cost products are usually very likely to cause remakes. There are two general reasons for this.

1. Some labs use cheap materials. In Robust, however, we only use IPS E.max material.
2. Some labs recycle the used E.max material and mix it with the new material.

Both of these two solutions can effectively decrease the cost, but it is very likely to cause cracking and result in inconsistent and unattractive shades.

6. Our suggestion of preps for E.max cases

We have some suggestions about preps for E.max crowns.

1. The edge of the preps can’t be too sharp. With an E.max crown, there is no metal support. A sharp edge can easily cause breakage.
2. If possible, prepare a shoulder margin is recommended. It can result in the perfect fitting.

The client received his E.max crown a week later, and he was very happy with it. However, he had to pay extra for this remake case that was made by others. This is something we always want to avoid for our customers. A remake is not only wasting time but also wasting money. Remaking for the second time would cause more loss for clients. That’s why they don’t want to change suppliers if they find a reliable one.