Problems / Disadvantages of Lumineers®
The placement of ultra-thin porcelain veneers (like Lumineers®, Vivaneers®, DURAThin®) using a no-drilling/no-shots protocol has its critics. Two of the major problem issues that are typically mentioned are:
- Subpar esthetics - Ultra-thin veneers have a reputation for needing to be comparatively opaque, as opposed to more translucent and life-like.
- Tooth bulkiness - No-tooth preparation placement can easily result in bulky, over-contoured teeth. That can make new veneers hard to get use to. It can also make the teeth they're placed on harder to clean.
Proper case selection is the key.
In response to these criticisms, dentists who favor the use of Lumineers® (or equivalent product) are quick to point out that these issues can be kept in check by way of proper case selection.
We'd generally agree. Many of the problems associated with Lumineers® placement tends to stem from the aggressive sales tactics of dentists who push the envelope about when no-tooth preparation protocol should be used.
An attitude of "just as long as the patient is informed and willing to compromise" is frequently given as justification for going ahead with the procedure.
We're not so sure how ethical that stance is, considering how little most patients seem to comprehend about this subject. Hopefully the contents of this page can help with that. Additionally, patient's should also consider possible alternatives.
Potential problems and concerns with Lumineers®.
1) Difficulty in achieving a natural-looking result.
a) Ultra-thin veneers are frequently very opaque.
The wafer thin veneers used with no-drilling protocol are sometimes criticized because for some applications for which their used they must be made using comparatively opaque porcelain and/or placed using relatively opaque cement.
This can be especially true in cases where they are used to make a big color change for teeth, such as those with severe discoloration or stains. (It's the opaqueness of the porcelain/cement combination that helps to keep the darkness of the underlying tooth structure from showing through.)
How tooth enamel handles light. (Use the in-text links for an explanation.)
Why is opaqueness a problem?
Tooth enamel, the part of a tooth that a veneer tries to mimic, is translucent. And a great deal of what gives a tooth its lustrous look has to do with the way light enters into this layer and is then reflected back out. (See diagram.)
If a veneer (or veneer/cement combination) doesn't accurately simulate enamel's light-handling effect, it won't look natural.
Take the case where an ultra-thin veneer is used to lighten the color of a darkly stained tooth.
- Since it's so thin, to effectively mask the stained tooth structure that lies underneath the veneer must be made using relatively opaque porcelain.
- But due to this opaqueness, light will tend to reflect off the veneer's front surface and not penetrate into it like it does when it strikes enamel (the link below illustrates this point).
- Because of this difference in light handling, the veneer won't look truly life-like.
(This is the exact same problem that occurs with dental bonding. This page explains and illustrates this phenomenon in detail, just substitute the words "dental bonding" with "opaque veneer.")
How traditional veneers differ.
Because they are thicker, conventional porcelain veneers can be made out of comparatively more translucent porcelain, yet they are still able to mask dark tooth structure that lies underneath them.
That means light will be able to enter into and reflect back out of them in a fashion that truly mimics the lustrous look of a natural tooth. (This page explains and illustrates this issue in detail.)
Also, a thicker laminate generally offers the dental technician more opportunity to incorporate characterization and shading qualities into the veneer itself by way of using different shades of porcelain in its fabrication (see images below). (DiMatteo, 2009). [page references]
Many people don't appreciate this difference.
We do have to admit that when it comes to the issue of obtaining a precisely life-like result, many people just don't seem to care.
The ease and pain-free advantage that no-drilling/no-shots technique offers simply outweighs the disadvantage of a less than perfectly natural-looking outcome.
Trends have changed.
That's probably because people's attitudes about tooth appearance have changed over the last 25 years, likely due to the explosion of tooth-whitening options that have become available over this same time frame.
Whitening processes tend to rob tooth enamel of translucency. And as a result, the patient ends up with a set of uniform snow-white "Chiclets" (teeth).
Nowadays, it seems that that is the look a lot of people are seeking. And if that's the one you want, it's easy enough to get with a set of Lumineers®.
b) Problem situations.
Especially in the case where only one or a few veneers are being placed, the increased characterization that's possible with a (thicker) conventional veneer may be an important asset in creating a perfect match with the patient's neighboring teeth.
The two teeth shown in our graphic illustrate this point. Both teeth have a nice appearance. One does, however, look more life-like and the other more "plastic."
- A - This tooth displays pronounced color uniformity and lack of characterization. It would be relatively easy for a dentist to place an ultra-thin veneer that would match this tooth.
- B - This tooth demonstrates a fairly high degree of translucency at its biting edge (the grayness you see). And its color is not perfectly uniform. It would be relatively difficult to mimic this look with an ultra-thin no-prep veneer.
2) Bulky, over-contoured teeth.
Another criticism of placing Lumineers® using a no-tooth preparation technique is that it can result in teeth that are too bulky and over-contoured.
It's easy enough to see how placing no-prep veneers could result in this outcome. After all, if you bond a shell of porcelain over the surface of a tooth without trimming it back first, its overall dimensions will be larger. It's only a question of how much and if it's enough to cause problems.
Case selection is key in avoiding this outcome. When Lumineers® are placed to just make minor enhancements and upgrades, the results can be quite acceptable. But when what is trying to be achieved lies beyond general guidelines, a problematic outcome can be expected.
a) What are some of the potential problems?
1) An artificial appearance.
Placing restorations that create larger, fuller teeth frequently results in a look that's artificial. And in extreme cases, the term "horse teeth" sometimes applies.
Of course, the degree to which this occurs is the key. And case selection is always a primary determinant.
But even so, when compared to the convenience and comfort of being able to take advantage of no-drilling/no-shots technique, for many people this is an easy enough trade-off to choose.
2) Problems with function.
Another area of concern is how the increased size of the veneered teeth will affect the person's daily activities.
Larger teeth can be cumbersome. They may also affect the person's speech or the way they bite into things. Additionally, they can change the way their lips are supported, position themselves on their teeth or even close together.
Fortunately, over time people tend to adapt to these types of difficulties. It's just a matter of how extreme the change has been.
3) Periodontal problems. / Tooth decay.
If you bond a porcelain veneer directly onto the untrimmed surface of a tooth, it will change the tooth's contours in the sense that there will now be a ledge (a "speed bump") right where the veneer ends (see our graphic).
(Dentists refer to this as affecting the "emergence profile" of a tooth, meaning altering those contours in the region where it exits its surrounding gum tissue.)
Over-contouring of this sort can:
- Make it more difficult to remove dental plaque (especially right at the gum line).
- Tend to interfere with the natural cleansing action created by a person's lips and cheeks as they slide against tooth surfaces.
(In general, under contouring a dental restoration is typically the better choice than over-contouring. And placing no-drill Lumineers® seems to break this rule of thumb.)
When dental plaque is not removed, problems such as tooth decay and periodontal (gum) disease can occur.
Of the two, experiencing gum issues is the more common occurrence. And it should be pointed out that just a minor amount of gum recession can easily spoil the appearance of a set of veneers.
Research into the matter.
Several studies have evaluated how an over-contoured dental restoration tends to affect the health of the surrounding gum tissue.
As an example, one study (Deng 2001) determined that:
- Increasing the contours of a tooth as little as .5mm can cause adverse affects.
- A .2mm increase resulted in no statistically significant problems.
Since Lumineers® can be fabricated as thin as .2mm in thickness, the above findings seem to confirm that placing them using a "no drilling" technique can produce acceptable results.
The potential for problems comes into play when this technique is used when ideal pre-treatment conditions do not exist. This would include placing ultra-thins as a way of creating "instant orthodontics" (see example below), especially with cases involving protruded or severely crowded or rotated teeth.
Ultimately, a person's oral home-care habits may be the most important factor.
Some studies (Ehrlich, 1980 and Kohal, 2003) have determined that the most significant issue associated with over-contoured restorations is the effectiveness of the person's oral hygiene. Those people who put in the effort and do an effective job do not develop problems.
This seems to justify (rationalize) the placement of no-prep veneers, even in situations where the resulting contours of the teeth will be less than ideal. However, one must realize that doing so commits them to performing satisfactory oral home care, every day, for the rest of their life. (How many people do that?)
b) Problem situations.
Here's an example of the type of case where the placement of no-drill Lumineers® could easily result in teeth that are too oversized.
It involves the situation where veneers are placed to improve the apparent alignment of crooked teeth. (Dentists refer to this as "instant orthodontics.")
1) The no-prep approach.
Our first graphic illustrates how the veneers, while ultra-thin in some areas, will need to be relatively thick in others.
That's the crux of the problem we've been discussing. With a no-tooth preparation approach the veneers alone make up the needed thickness variations. And as you can see, using this method can easily result in bulky or over-contoured teeth.
2) The conventional approach.
Our second graphic illustrates the use of conventional veneering technique.
With it, the most prominent portions of the teeth are trimmed back first and then the veneers are made and placed.
Using this method, each tooth's contours can be kept within normal limits.
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