The superior fit of custom-made bleaching trays helps to enhance the whitening process and minimize user discomfort.
[ If you don't already know... what exactly are "custom" trays?
The term "custom tray" refers to teeth whitening trays that are made in a dental laboratory specifically for that person who will wear them.
Making custom bleaching trays for a person first starts with taking impressions of their teeth and surrounding gum tissue. These impressions are then used to create plaster casts. The custom trays are fabricated directly on the person's plaster casts, thus ensuring an accurate and customized fit.]
What aspects of a bleaching tray's need to be customized?
1) The outline and specific contours of a whitening tray should be personalized.
One of the biggest advantages that a custom bleaching tray can offer (as compared to a stock tray) is the way that it has been trimmed so to fit along the wearer's gum line.
The idea is that a tray's edges should fully cover over the surface of each individual tooth, yet not significantly cover over any portion of the user's gum tissue (as illustrated in our picture below). The reasoning that lies behind this design approach is as follows:
A) Properly trimmed tray edges help to minimize gum tissue irritation.
A design where the edges of the whitening tray lie just short of the gum line can help to minimize the amount of soft tissue irritation that is experienced by the wearer during the bleaching process.
A properly trimmed tray helps to minimize the contact of (potentially irritating) bleaching gel with gum tissue. (This can be especially important in those instances where a relatively higher concentration whitener is being used.) It is also possible that the edge of a bleaching tray might rub against the wearer's gums and be a source of mechanical irritation.
B) A bleaching tray should cover over the entire surface of each tooth.
An even whitening effect can only be predictably produced when the whitener being used has a chance of being in contact with the entire surface of a tooth.
If a bleaching tray has an outline shape where it significantly falls short of covering the entire front surface of each tooth being treated, the whitening effect that results may not be precisely the one that the person had in mind.
2) A personalized fit helps to insure proper tray retention.
When a bleaching tray is worn its fit should be one where it stays in place well. Typically, the personalized fabrication process associated with making custom bleaching trays can be counted upon to provide this type of fit.
It is possible that this point of concern may not be much of a factor with either type of bleaching tray (custom or stock). When a tray is loaded with whitener, the gel creates a cohesion effect that usually helps to keep even a loose fitting tray in place. (It will, however, take more whitener to adequately fill a poorly fitting tray.)
3) A custom tray can be designed so to include bleaching gel reservoirs.
An added advantage of custom teeth whitening trays is that they can be designed so to feature bleach reservoirs. Reservoirs are simply small spaces (such as one running along the entire front side of a tooth) intended to hold an additional (although minute) quantity of bleaching gel.
The idea associated with reservoirs is that since they contain an additional quantity of whitener, the tooth surface facing them receives exposure to a greater number of bleaching molecules.
The need for reservoirs is not universally agreed upon in the dental community. For more information, use the following link to visit our page that discusses Bleaching Tray Reservoirs in greater detail.
A compromised fit. - The reality of stock bleaching trays.
Custom bleaching trays are fabricated with specific design characteristics in mind (as described above). In comparison, stock whitening trays (such as those contained in store-bought kits), even including those trays that can be user modified, cannot predictably offer these same features and advantages.
1) The fit of a stock whitening tray over the wearer's teeth is seldom ideal.
One deficiency typically associated with stock bleaching trays is that they don't fully cover over the entire front side of the teeth being treated. And in some cases this may make it impossible for the wearer to achieve an even whitening effect (the tray-covered portions of the teeth do lighten but the exposed surfaces do not).
2) The edge contours of a stock whitening tray typically extend over the wearer's gums.
Essentially all stock whitening trays will extend over the wearer's gum tissue to some extent. And it is possible that this contact may cause mechanical irritation to the user's gum tissue. (Of course, a simple solution for this problem is to trim back the offending portion of the tray.)
Usually the bigger problem associated with overextended whitening trays is that they will create a situation where the bleaching gel is held in direct contact with the wearer's gums.
This may not be much of a problem for most people but for some this can prove to be a significant difficulty. Especially in those situations where a relatively higher concentration (and therefore potentially more irritating) whitener is being used, or else the time frame associated with each individual bleaching treatment is comparatively long.
