UV Curing
The principles outlined in this course are standard UV curing protocols. Some resins may have additional special conditions to be aware of. Reference the individual material courses, Lab Reference Grids and Dental Post-Processing Grids for more information.
A quick reference guide for general steps in dispensing can be found in the Process Overview.
UV curing exposes parts to additional UV light after the printing and washing process.
- Completes the curing process started during printing, giving parts their final mechanical properties.
- Makes parts safe to handle.
- Required to cure all one-part, single-cure resins.
UV curing may be used with select two-part resins prior to packing parts in salt.
Parts still require a thermal curing process even if UV cured first:
- To reach their final mechanical properties.
- To be safe to handle.
Parts printed in resins such as RPU 70 and RPU 130 may require UV curing prior to salt baking per resin protocols.
- UV light may be used in short duration to provide an additional thin layer of green state curing on the surface of a part.
- The thin layer of UV curing minimizes the chances of salt sticking to the part during salt baking.
Generally, UV curing is not recommended for the following resins
- EPX 82, EPX 150
- No benefit to using UV curing prior to salt baking. UV curing simply adds an extra, unnecessary step.
- Elastomeric resins such as EPU 46 and SIL 30
- Elastomer resins do not use salt baking because they will either retain the salt on their surface or retain a permanent abrasion.
- FPU 50
- UV curing can cause brittleness.
Most UV ovens project light from the top-down. The Dreve PCU LED is the rare exception, projecting light from above and below.
- Only surfaces that are struck by light are cured. Undersides of parts or areas that are in shadow are not cured.
- Each part will need to be rotated until all surfaces have been exposed to the UV light.
The example part pictured below must be rotated four times in order to expose all surfaces to UV light.
Keep this information in mind when positioning parts in the UV oven for curing.
All resins
- Put on fresh gloves before starting the curing process to avoid resin contamination from previous steps.
- Always use a gloved hand on the oven door or to push buttons on the oven because these surfaces may be contaminated with uncured resin.
- Never handle an uncured part with bare hands because you will expose yourself to uncured resin.
One-part resins
- Keep gloves on until all sides of the part are fully cured.
- Always use a freshly gloved hand to remove fully cured parts from oven to check for tackiness before handling with bare hand.
- After the part is fully cured, remove the part from the lab without touching any contaminated processing areas.
Two-part resins
- Keep gloves on throughout process because parts are not fully cured until they go through thermal curing.
UV curing is a relatively simple process:
- Place parts in UV oven.
- Set the timer or select the program appropriate for the resin used.
- Start the curing process.
- Rotate parts if necessary and repeat curing.
- Check parts for tackiness and repeat curing if necessary.
- Remove parts from UV oven.
Click the links below to learn how to operate specific UV curing units.
- While the part is going through its final UV cycle, change to a new pair of gloves.
- Your old gloves are contaminated from handling the uncured part/tray. Continuing to use these gloves will spread uncured resin to your freshly cured part.
- When the final UV cycle is complete, test the part for tackiness with your freshly gloved hand.
- If the part is not tacky, remove it from the oven and move it to a contamination-free area.
- If the part is still tacky, follow the resin protocol to remove tackiness.
