Bruxism is also known as night grinding or teeth clenching. It is an involuntary action that is often observed when the person is asleep, usually at night time, but can also be seen in the day. A person suffering from this condition have overworked muscles and as a result, they have badly worn teeth of varying degrees and may be present on the anterior or posterior teeth (or both).
While there are some known treatments that can resolve this issue, they are not popular so the only method patients can explore is to prevent any further damage. Patients cannot control their clenching habits and if it cannot be stopped, the teeth will have to be given some protection --- and that is why night guards are prescribed.
Ideally, a night guard is worn at night (or every time the person sleeps) so that their teeth can be protected from the effects of their bruxism habits. The night guard is constructed using a tough rubber material which works as some kind of covering, cushion or shock absorber. Any force supposedly directed to the teeth will be received by the night guard, so you preserve the teeth and wear out the appliance instead.
Custom or Ready-Made
In the dentist's office, night guards are custom-made, so to make sure they perfectly fit the patient, an impression will be taken so that a cast can be created, and the night guard will formed over the cast. As a result, the patient will get an appliance that sits perfectly on his jaw, fitting every single tooth into the mould formed. What is produced, therefore, is an appliance that is comfortable to wear, does no dislodge and does not pose any harm to the patient.
Ready-made trays are more generic in size and fit, designated only as small, medium, large (and so forth) so when worn they will not offer a snug fit unlike the custom-made mouthpiece. They are more affordable and are readily available, but they are often made of a cheaper type of material that will not offer enough protection for the teeth. Since it does not fit well, it moves in the mouth and can be quite uncomfortable and dangerous to wear during sleep. As a result, the patient will make an irresponsible decision to do away with the appliance and not wear it at all, so constant night grinding will continue to cause damage to the teeth, the bite and the overall health of the patient.
One thing that you have to understand is that Bruxism and night grinding is a serious condition. It may not seem like it is, but the problem it causes can be very damaging. The severe wearing away, especially of the posterior teeth, can lead to a collapsed bite. This can bring about serious TMJ conditions which cause excruciating pain and discomfort to the patient and treating problems as serious as this one is not only more complicated, it is more costly and more tasking for both the patient and the dentist, compared to a simple custom night guard.