Invisalign Advantages

The most obvious advantage of the treatment is cosmetic: the aligners are completely transparent, therefore far more difficult to detect than traditional wire and bracket braces. This makes the method particularly popular among adults who want to straighten their teeth without the look of traditional metal braces, which are commonly worn by children and adolescents. In addition, the aligners are marketed as being more comfortable than braces. Due to the removable nature of the device, food can be consumed without the encumbrance of metallic braces.

Clinically, aligners avoid many of the side effects of traditional fixed appliances, for example the effects on the gums and supporting tissues.Fixed appliances are known to cause the roots of teeth to shorten for most patients, and demineralisation or tooth decay occurs in up to 50% of patients because they cannot be removed for eating and cleaning, and because they prevent accurate x-rays from being taken. Patients "graduate" to a new set of aligners in their treatment series approximately every two weeks. The aligners give less force per week and less pain than do fixed appliances (traditional metal braces). Fixed appliances are adjusted approximately every six weeks and apply greater forces.

Aligners should be removed to eat, drink, to clean the teeth, or to have them checked by the clinician. (It is acceptable to wear aligners while drinking water.) Computerized treatment planning is compulsory as part of the Invisalign protocol. As with other forms of orthodontic treatments that incorporate a computerized plan, this allows the prospective patient to review the projected smile design, learn how long the treatment is likely to take, compare different plans, and make a more educated decision about whether or not to use Invisalign.

Invisalign treatments have been claimed to be quicker than traditional orthodontics. A large-scale study of 408 patients with traditional appliances in Indiana took an average of 35.92 months with a maximum of 96 months, while Invisalign takes between 12–18 months. In a much smaller study Invisalign was shown to be faster and achieve straighter teeth than alternatives but relapsed to ultimately get similar results to the traditional appliances examined. The study was considered by the authors, however, to be too small for many conclusions to be statistically significant. Furthermore, this general concept that Invisalign is faster has been challenged by the Invisalign review which points out that there are other brace appliance systems that take half the time, for example by incorporating surgery or temporary implants that insert into the patient's bone, to accelerate the procedure.

Invisalign Disadvantages

The product also has potential disadvantages: the very fact that the aligners are removable means they are not continually correcting the teeth. Unlike traditional fixed braces, they are largely dependent on a patient's habits and their consistency in wearing the aligners. The success of the Invisalign aligners is based on a patient's commitment to wear the aligners for a minimum of 20–22 hours per day, only removing them when they are eating, drinking, or brushing their teeth.

The system is also somewhat expensive, as conceded by the Align company, and can be more expensive than traditional wire and bracket systems.

The aligners must be removed for eating. They and the teeth should be cleaned before re-inserting afterwards.

Because the aligners are removed for eating, they can become lost. Invisalign recommends that the patient keeps the previous aligners in case this happens.

Certain teeth are slightly problematic for Invisalign aligners to rotate. Some lower premolars with their rounded shape can be difficult for the aligners to grasp and apply a rotational force to.

Unlike traditional braces, if a patient grinds or clenches his or her teeth during the day or while sleeping, the aligners can become damaged. In practice, however, this problem is very rare and a new aligner can be ordered. Also, similar to traditional metal braces, aligners may cause a slight lisp at the beginning of treatment. This usually disappears as the patient becomes used to the treatment.

The aligners are constructed of implantable grade polyurethane, and the Align company has acknowledged that, though extremely rare, there may be cases of allergic and toxic sensitivity reactions to Invisalign. Minor symptoms such as sore throat, cough, and nausea have been reported. In more serious cases, the FDA has received reports of systemic swelling or throat pain that has extended to the upper chest and wind passages requiring emergency medical treatment and discontinuation of the Invisalign treatment.While the Invisalign company provides no information except the MSDS (material safety data sheet) directly to patients or orthodontists, working through the patient's orthodontist Invisalign will make the aligners with several different materials to attempt to reduce toxic or allergic sensitivity.

Should the treatment go off track, or patients fail to keep the aligners in for the required length of time, then the next aligner in the series will not fit, and a new set of impressions and aligners will be necessary, adding to the cost.