MAKING AN 'IMPRESSION'

Dentistry's roots date back to prehistoric times when the practice consisted mainly of tooth drilling and extractions. The science of modern dentistry can be traced back to the 17th century when prosthetics and fillings were added to the original list of treatments. Since its humble beginnings, the field of dentistry has advanced and grown to include preventative, surgical, restorative and cosmetic areas as well.

Today dentists, orthodontists and oral surgeons need advanced technologies to support their advanced care of the teeth, gums and supporting bone structures.

For the last 25 years, GKS Inspection Services has been a provider of dimensional inspection, 3D laser scanning and CT scanning services for dentists who offer their patients innovative treatment options. The company's metrologists and engineers are experienced in many manufacturing industries and have often been sought out to scan teeth, bones, and plaster casts of teeth and mouths as a means to provide dentists with faster and better oral health solutions.

The recurring theme, and the biggest challenge, in scanning dentalrelated items is their organic nature; teeth, bones and soft tissue shapes are very complex, free-form and amorphous - and extremely difficult to replicate with traditional measurement methods.

Fortunately, non-contact 3D laser scanning's forte is very accurately recreating difficult organic shapes, such as those found in the field of dentistry, which puts a smile on everyone's face.

Dentists and oral healthcare professionals need to digitally replicate their patients' mouths for many reasons.

Once the physical model is made, GKS laser scans it thoroughly to bring it into the digital world. The process is automated and a whole mouth scan takes only a few minutes. The scan data is extremely accurate and can be used in many dental applications. Here is an look at some of the dental applications.

GENERAL DENTISTRY

Dentists work to restore the natural look and fit of decayed or missing teeth perfectly.

The process starts when the dentist makes an impression of the patient's mouth with a pliable silicon material. The patient bites down on the flexible block to lift impressions of both the top and bottom teeth and the oral cavity. From that impression, a model is cast with plaster which faithfully reproduces the mouth's unique geometry.

If an extraction or a crown is planned, then a replica of the original tooth is preserved in plaster. At this point, the plaster casts can be laser scanned quickly and accurately to produce digital data, and ultimately a CAD model from which to re-create the tooth or teeth that will be drilled or removed.

Crowns and bridges can be made to reproduce the real teeth so that the fit is just right. The clasps which hold these types of prosthetics in place must also be fit correctly to the remaining teeth to be secure and stable.

ORAL SURGERY

When surgery is required to extract several decayed or broken teeth, impressions are made beforehand so partial and complete sets of dentures that match the original teeth can be made.

The modeling process is the same as for general dentistry applications, only more of the teeth and mouth shape will be recreated for partial or full dentures.

For patients with few or no teeth, an impression must precisely recreate the entire oral cavity, especially the toothless gums. Fit to the top or bottom arches and gums is critical. Slippage must be minimal to prevent sore gums and ensure an effective bite. To this end, the impression or the interior surface of the denture base must be extremely accurate so the dentures will securely seal against it. Laser scanning the impressions creates an amazingly detailed model for an accurate fit.

ORTHODONTICS

From the laser scans of an orthodontic patient's teeth, digital models can be manipulated to simulate the individual's progress from ongoing corrective treatments, and to manufacture devices to correct tooth alignment at every stage. The patient only needs to have one set of impressions made, an attractive option since the process can be time-consuming and somewhat uncomfortable. The subsequent device fitting is done through progressive CAD models of the patient's teeth that digitally show the various stages of corrections.

ORAL HEALTHCARE

In order to design and manufacture oral healthcare items such as toothbrushes, electric toothbrushes, flossing devices, etc., a designer must have accurate measurements of a great number of teeth and mouths' size, shape, and "layout" to assure a good fit and comfortable use in the general population. Laser scanning is a time-efficient and money-saving method to obtain measurement data on the geometry of thousands of oral cavities.

ARCHIVING IMPRESSIONS

Plaster impressions are very accurate representations of patients' mouths, and they last as long as needed.

However, storing hundreds of sets of teeth can tax any office's space constraints.

Also, plaster impressions are breakable, so they must be carefully archived and stored separately.

Laser scanning impressions into digital data virtually eliminates the need for physical storage space.

Once a plaster impression is digitized, there is no need to store the physical item and the data cannot be broken or damaged.

DENTAL RESEARCH

Plentiful scan data records mean that they can be compiled and analyzed for research purposes. If a condition or disease is prevalent within a population, cures or preventative measures may be found by modeling the characteristics or abnormalities found in the oral cavities.

Data mining may also uncover unexpected or hidden trends and similarities within the groups studied.

REVERSE ENGINEERING

Laser scanning is the fastest, most accurate and automated way to acquire 3D digital data and a CAD model of a part's geometry when none are available.

Recreating complex free-form shapes is non-contact measurement's best application. Both the positive and the negative version of a scanned part are easy to create, so no matter what part of a manufacturing process is lacking, 3D laser scanning can provide the correct type of data file. Also, new features and updates can be integrated into old parts once the modeling is accomplished.

INNOVATIONS IN DENTISTRY

Whether creating new teeth, appliances, products and devices, or studying dental issues of a given population, modern oral healthcare practitioners and product developers are availing themselves of the advanced technology of 3D laser scanning to help them provide the best possible care for as many people as possible. Keeping a smile on people's faces is much more than just another way of saying "have a good day." It is a matter of maintaining an innovative up-to-date dental practice and good health.

GKS Inspection Services
Minneapolis, MN
gks.com