Life has changed significantly over the past few centuries. Dentistry, too, is a vastly different practice. Just take, for instance, the evolution of the dental impression technique: from the use of wax and plaster of Paris in the 1700s to today’s intraoral scanners.

In 1787, a dentist in New York advertised a new service. Patients could take their own wax dental impression at home, send it to the dentist, and receive custom-made dentures in return. Granted, these DIY homemade impressions probably didn’t reach the dentist in the same condition they left home. Considering temperature changes and mail handling, the wax likely changed shape somewhere along the line. Though not quite as revolutionary as say, being able to order dentures online, it was nonetheless an impressive development for the time.

The building blocks of modern dentistry were laid on some unconventional (and questionable) foundations. Despite the unusual methods and materials used, these new approaches to impression-taking set the dental profession on the path of progress and innovation. As a result, restorative dentistry has undergone an impressive (pun unintended) transformation, marked by improved accuracy, safety, comfort, functionality, and patient satisfaction.

Intraoral scanners: the evolution of taking a dental impression
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Dental Impression Materials

Although archaeological evidence shows Etruscan prosthetics requiring dental impressions from as early as 600 BC, there is no surviving evidence for how they took these impressions to carry out the work.

The earliest documented impression materials date to the mid-1700s. The following are some important touchstones in the dental industry’s evolution.

Sealing Wax

Dr. Philip Pfaff (1713–1766), a German dentist to the King of Prussia, developed one of the first-known techniques to take a dental impression using sealing wax. At that time, wax was largely used to seal envelopes and important documents because it softens with heat and hardens quickly. On hardening, it forms a strong and rigid bond and maintains its shape well.

Dr. Pfaff took impressions with sealing wax softened in hot water and molded to the teeth. He poured plaster of Paris into the impression to form a rigid cast.

Beeswax

Beeswax was another type of wax and became popular as a dental impression material. John Greenwood, a pioneer of 18th-century dentistry, developed some of the best-fitting upper dentures of the time using beeswax. From the beeswax dental impression, he made a die on which he shaped a sheet of gold. Greenwood used this method to create dentures for George Washington.

Plaster of Paris

Traditionally used as a casting material, plaster of Paris was also used as an impression material from the mid-1800s. Despite offering accuracy of detail and dimensional stability, its original formulation wasn’t fast setting. This made impression-taking a messy and time-consuming ordeal.

Plaster of Paris also lacks elasticity and is a particularly brittle material to work with once set. Dentists had to use a mallet to tap it out—leading to material distortion and fragmentation—and then reassemble the impression outside the mouth. Moreover, excessive salivation during the setting process would negatively affect the accuracy of the impression. Nonetheless, plaster of Paris remained a commonplace choice for dental impressions, even up to the 1950s.

Impression Compounds

Beeswax and plaster of Paris were the only dental impression materials available until 1856 when Dr. Charles Stent began utilizing a natural thermoplastic compound derived from the Malaysian gutta-percha tree. However, like plaster of Paris, the material became too rigid after setting and couldn’t reproduce undercut areas with precision. Restorative dentistry needed a better solution. The answer was to develop moldable impression compounds using a material sufficiently elastic to remove from the mouth without distortion.

From the late 1930s until the 1950s, two highly-elastic derivatives of algae—agar and alginate—gained prominence. However, they also had disadvantages, including dimensional instability and low tear strength, and were succeeded by other, better-performing materials. These included polysulfide rubber in the late 1950s, polyethers in the 1960s, condensation and addition silicones, and vinyl poly siloxane (VPS).

Today’s modern compounds are moldable plastic when heated to 149°F (65°C) in a water bath. When inserted into the mouth in an impression tray, they set at body temperature. Further, because of their low degree of thermal expansion, dimensional change is minimal, and there’s no adherence to oral tissue.

Dental Impression Tools

Impression Tray

Impression trays are as important as the materials being used. From the 1800s to the present day, trays have evolved from metal and porcelain types to thermoplastics. Current water-cooled impression trays have an interior lining. When capturing an impression, cold water moves through the lining, helping to cool and set the material. These trays are especially effective with reversible hydrocolloid impression materials.

Impression trays aren’t necessarily one-size-fits-all; dentists can customize them for individual patients. A tailormade tray ensures that the impression material distributes more accurately, resulting in a better fit.

Source: Shutterstock

Intraoral Scanner

Even with today’s modern materials, taking a dental impression can be error-prone, time-consuming, and uncomfortable. Intraoral scanners overcome these limitations by creating a digital impression of the oral cavity.

With the integration of CAD/CAM technology, the handheld scanner captures and processes a full 3D oral imprint to a touch screen in real time. High quality, accurate details of hard and soft tissue ensure excellent results

The use of intraoral scanners is growing, thanks to benefits such as more intuitive workflows, shorter lab turnaround times, improved case acceptance, greater precision, and easier treatment planning.

Dental Impression Simplified With Sterngold

The evolution of dental impression materials and tools has resulted in greater restorative accuracy. For patients, this means better oral health; for dentists, it translates into significant time and money savings.

With digital solutions now available to solve traditional problems, there are fewer manual errors such as tears, voids, and bubbles. Dentists can offer completely customized solutions at lower costs while decreasing patient chair time and improving outcomes.

Sterngold has been part of the evolution of the dental industry for more than 125 years. As a leading source of restorative products, Sterngold continues to assist practices and labs in enhancing their workflows and services by embracing modern methods and technologies.

Having a reliable dental supplies partner—providing restorative products from medical device, equipment, provisionals, and yes, dental impression material —helps clinicians and lab technicians minimize disruptions to maximize productivity.

In addition to the extensive range of restorative dental products, Sterngold delivers a consistently great customer service experience and expert continued education. Chat with a Sterngold team member today to get your practice to the next level.