When it comes to achieving precise and reliable dental impressions, the materials used get most of the attention—but there's one tool that often goes unnoticed: the dispensing gun. While impression materials like VPS (vinyl polysiloxane) or polyether are essential for capturing fine anatomical detail, the method of delivery is just as important for consistency, efficiency, and accuracy.
In this blog post, we’ll explore what dispensing guns are, how they work, and why they’re crucial for high-quality dental impressions.
What Is a Dispensing Gun?
A dispensing gun (also known as a mixing gun or cartridge dispenser) is a handheld device used to mix and extrude two-part impression materials directly from a cartridge. These cartridges typically contain a base and a catalyst, which must be mixed in precise ratios to ensure proper setting and performance.
The dispensing gun automates this process, allowing for:
- Consistent mixing
- Reduced air entrapment
- Controlled flow
- Quick application
Dispensing guns come in various sizes and ratios (e.g., 1:1, 2:1, or 10:1), compatible with different cartridge systems used across dental procedures.
How Dispensing Guns Work with Impression Materials
Impression materials like VPS, polyether, or alginate substitutes are often packaged in dual-barrel cartridges. These cartridges are loaded into the dispensing gun, and a mixing tip is attached to the end. When the trigger is pulled, the plungers push both materials through the mixing tip, where they are automatically blended and dispensed in a ready-to-use consistency.
Here’s a step-by-step overview of how they’re used in practice:
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Load the cartridge into the dispensing gun.
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Attach the mixing tip, which ensures homogeneous blending.
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Purge a small amount to eliminate voids and ensure even flow.
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Apply the material directly to the impression tray or intraorally around the tooth preparation.
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Allow the material to set, and proceed with impression removal as usual.
Benefits of Using Dispensing Guns in Impression-Taking
1. Improved Accuracy
Uniform mixing eliminates inconsistencies in material set time and texture, reducing the risk of voids, bubbles, or distorted impressions.
2. Time Efficiency
Manual mixing can be time-consuming and error-prone. Dispensing guns speed up the process, making it ideal for busy practices.
3. Hygienic and Low Waste
Closed systems reduce contamination risk and ensure that only the needed amount of material is used.
4. Ease of Use
The ergonomic design of most guns allows for controlled dispensing, even in hard-to-reach areas.
Clinical Applications
Dispensing guns and impression materials are commonly used in:
- Crown and bridge impressions
- Implant impressions
- Bite registrations
- Preliminary and final impressions for dentures
- Orthodontic appliances
Whether you’re capturing a detailed margin or recording occlusal relationships, the combination of a well-calibrated dispensing gun and high-quality impression material can make all the difference.