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Q-Crown

B.J.M. Laboratories www.bjmlabs.com

Consultants’ Comments

  • “I found it easy to remove from the tooth and easy to trim.”
  • “Temporary restorations were esthetic, looked natural and the glaze looked very nice.”
  • “Great product. Strong, easy to handle and esthetic.”
  • “The small tips mean there is little waste and they store nicely in the kit.”
  • “The material’s hardness and accurate fit are both a strength and a weakness. We had to section off our long-term temporaries, but the material served its purpose.”
  • “Patients did not like the taste.”
  • “The material fractured easily, and crowns were brittle. It needs to be stronger.”
  • “Margins were not crisp.”
  • “I found it less user-friendly compared to other auto-mix materials.”
  • “I would like to see it available in a gun dispenser and auto-mix capsules.”

Clinical Tips

  • Use a timer and make sure that you pay attention to the working time.
  • To help prevent the material from sticking to the tooth, apply lubricant to the preparation before creating the temporary.
  • To avoid bubbles, be sure to bury the syringe tip when extruding the material from the syringe.
  • Spray the interior of the impression with a silicone spray.
  • I would include this is my armamentarium to have on hand for bruxers.
  • Best for long-term temporaries.

Evaluation Highlights

Q Crown was evaluated by 32 consultants for a total of 395 times.

  • Fast set.
  • Good fit.
  • Low shrinkage.
  • Easy to trim.
  • Esthetic temporaries in the available shades.
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Indication

Direct temporization chairside.

Unique Features

  • Exceptionally tight marginal seal for precision fit and high mechanical strength, making it suitable for long-term temporary crowns and bridges.
  • Polymerization does not cause a high-temperature exothermic reaction.

Description

Q-Crown is a resin-based, biocompatible, self-curing direct temporization material. After mixing, self-curing takes 3 minutes. Q-Crown offers high compressive strength (180-220 MPa after 24 hours) and flexural strength (40-60 MPa after 10 minutes; 120-150 MPa after 24 hours). Initial set occurs within 1 to 1.5 minutes of mixing. The temporary should be removed from the preparation(s), together with the impression, during the initial set at 1 to 1.5 minutes while it is still easy to remove. The temporary is removed from the impression 2 to 2.5 minutes after mixing and excess removed, before wiping the temporary with alcohol to remove the air-inhibited layer. Final set takes 4 to 5 minutes from initial mixing, after which the restoration is finished and polished. Q-Crown glaze is used on the cemented temporary restoration and light-cured on each surface for 20 seconds, providing for a high gloss. Q-Crown is delivered in a kit with three, 5 mL automix syringes, one each in shades A, A2 and A3. Other components in the kit include 25 mixing tips, 25 microbrushes, 1 5 mL bottle of Q-Crown light-curing glaze and the manufacturer’s instructions for use.