More recent refinements have generally been incremental. Elastomeric materials are polymers that possess both viscosity and elasticity (like rubber) that proved better able to capture surface detail (Moldi, 2013). The development of hydrocollides (agar and sodium alginate) was a major advance, as these are hydrophilic materials that can capture accurate impressions despite the presence of some fluid, such as saliva and blood (Madhavan, 2015). The 1940s saw alginate being used for the first time for impressions, followed in the 1950s by the introduction of elastomeric materials (silicone based, polyethers and polysulphides). This led to not just better impression trays generally, but the possibility of individualised ones. Plastics were developed and became relatively inexpensive and widely available. The 20th century brought with it significant improvements to this process, mostly due to breakthroughs in material sciences and industrialisation. These early impressions would have been difficult to take and error prone, with innovations such as the impression tray and plaster of Paris only starting to be employed after 1840 (Goyal, 2014). This technique has its roots in the mid 1700s, when beeswax was used as the impression medium. Traditionally, measurements for dental prosthetics were taken with an impression material to create a negative imprint, using this to create a dental stone cast.

With advances coming thick and fast, it can be helpful to stop and re-examine how we got to today’s cutting-edge solutions, to better understand what is available and maybe even anticipate what tomorrow will bring. This method is growing in popularity because it is more accurate than traditional dental impressions and is generally more comfortable.Cheryl Hayes stops and re-examines how taking impressions has evolvedĭental impressions have been taken for centuries now. As we mentioned before, digital dental impressions are taken using a handheld wand and computer software. Polyether is also less likely to cause an allergic reaction in people with latex allergies.Īnother option for people with sensitive teeth is digital dental impressions. One common alternative is polyether, which is a putty-like material that sets harder than alginate. If you have sensitive teeth, your dentist may use a different type of material for your dental impression. The good news is that the alginate sets quickly, so the discomfort doesn’t last long! There are ways around this, so be sure to speak with your dentist if you are worried about your gag reflex. For some people, dental impressions can trigger the gag reflex. This creates an exact replica of your teeth and gums that a dental lab can then use to fabricate your dental appliance.ĭental impressions are not a painful procedure, but some people may feel a little uncomfortable when the alginate is placed in their mouths. At the dental lab, stone will be poured into the impressions made by your teeth and gums. Once your dentist has taken your dental impression, they will send it to a dental lab where it will be used to create your custom dental appliance. The tray will then gently be removed from the mouth. Once the trays are in place, the alginate will slowly “set” and harden into a rubber-like consistency. When used on the lower teeth, the tray will also cover the floor of the mouth and under the tongue. When used on the upper teeth, the tray will also cover the roof of the mouth.

Once the primary impression is taken, it is then used to create a tray that is customized for an individual patient. Custom Trays:Ĭustom trays are made from a primary impression taken using a stock tray. Most impressions can be successfully taken with stock trays due to the use of putty. They can be either plastic or metal and can either have rounded edges for people with no teeth or square edges for people with teeth. Stock trays come in a variety of shapes and sizes and are used to take primary impressions.

Stone dental impression