The name Invisalign is an acronym for’ invisible aligners’. It refers to an orthodontic device which is meant to be used as an alternative to the conventionally used dental braces for the alignment of the patient’s teeth. As the name may suggest it refers to a set of teeth aligners which are not normally visible. This is one of the ways in which it is superior to wire braces. Being a patented device it is manufactured only by Align Technology, the company which originally launched it.
The device has a very interesting history. It is one of those devices conceived not by a doctor but by a patient. His name is Zia Chishti. Mr chishti is neither a dentist nor an engineer (BA, Columbia; MBA, Stanford). Also, the device was initially not favored by the dental practitioners’ community, the objection being, possibly, that the designer had no medical qualifications and experience. However, the product was approved by the FDA in 1998. It has become very popular, even to the extent, that a certification on aligners has been made part of continuing education for dentists. It is reported that in 2012 two million people had used it.
The purpose and working concept of Invisalign is the same as that of dental braces for alignment of teeth. The braces gradually move and align teeth through a series of intermediate positions before reaching the final positions. The Invisalign also envisages the same. However, there are no wire braces to be tightened repeatedly by the dentist. The teeth are moved very slightly by wearing the first set of aligners which exerts a little corrective pressure on the teeth. It is worn for about two weeks, and by that time the teeth have moved a little. The next set of aligners is also worn for a similar period and moves the teeth slightly further towards the final corrected position. A few dozens of set are made and worn by the patient in order. The number of sets to be worn successively depends on the difference between the initial orientation and the final one.
- Radiographs – The dentist takes radiological photographs, conducts a bite registration, and takes gum and teeth impressions of the patient. An evaluation is made, resulting in a diagnosis, and a treatment plan is laid out.
- Study Models – A digital three dimensional model of the patient’s teeth is made from this information in a computer. This model is fed to specialized software. With the help of this software, the desired position and angulation of the teeth is determined. Multiple stages (many dozens, depending on the case) of tooth movement are generated within this software.
- Digital Modelling of the Study Models – A graphic representation of the simulated tooth movement is shown to the dentist. He modifies or approves the movement plan.
- Fabrication of the Aligners – The approved plan is used to create the aligners using computer controlled 3D printing, or they can also be fabricated in the laboratory using CAD/CAM technology. This process is variously called stereo lithography, resin printing, additive manufacturing, optical fabrication, solid free-form fabrication, photo-solidification, and solid imaging. The material used a thermoplastic which gives transparent aligners which are numbered and are to be worn in sequence.
Duration of Wearing Each Aligner
Each aligner is worn for about two weeks, twenty hours per day, giving a small movement to the teeth in the desired direction. The final positioning may take slightly over a year. Retainers are advised after that.
Pros and Cons
The invisalign offers convenience. It can be removed for eating and cleaning, and then reinstalled by the user. It is not as prominently visible as the braces. It is, however, more costly, by about thirty to fort percent. Also, the Invisalign may not be able to handle very complicated cases of misalignment. To see if invisilign is the right option for your orthodontic needs, please feel free to contact our Fort Worth office for a consultation appointment. We’d love to be a part of creating your perfect smile!