A Superior Denture Processing Method to Ensure Superior Fit
Denture acrylic undergoes a 7% shrinkage during processing, which greatly affects the fit of the denture. Armstrong Laboratory has attempted in the past to solve this problem by triple packing the denture under hydraulic compression. However, even this method is inadequate to fully address the
To help solve the problem of shrinkage, Ivoclar has developed the SR-Ivocap system. Through the use of controlled heat/pressure polymerization, the laboratory can compensate for shrinkage by pressure feeding
additional material during processing. This technique thus insures high quality finished prosthetics that have excellent physical and clinical characteristics.
Technique(see Illustration Above): The SR-Ivocap system continuously injects fresh acrylic into the processing flash for 5 minutes under 6 bar of pressure. The curing temperature is controled so that the anterior portion processes first while new material is injected into the posterior portion. Injection pressure is maintained during the subsequent polymerization and cooling.
SR-Ivocap, as with other injection systems, has a higher monomer to polymer ratio in the acrylic used. It is therefore more likely to cause problems with allergic reactions then conventional processing.
Therefore, this system is not recommended for patients who have had allergic reactions to denture acrylic in the past or for patients with sensitive allergies. If your patient demonstrates allergic reactions to denture acrylic, it is recommended that you prescribe Vacalon as the processing method. Unfortunately, Vacalon and Ivocap are incompatible processing methods.
The SR-Ivocap injection technique offers you and your patients decisive advantages over conventional packing procedures:
Superior Fit: The patient receives a denture that fits, that provides proper suction, and that has no pressure points.
No Increase in Vertical Dimension:
This technique avoids vertical dimension increase, reproduces precise occlusion, and thus practically eliminates re-occlusion and grinding.
This technique assures maximum degree of polymerization, strong chemical bond with resin teeth, and lasting color stability.
SR-Ivocap: A Proven System
The unparalleled success of the SR-Ivocap system is based on more than 15 years of solid performance involving 9000 laboratories around the world. Well-known practitioners have published articles and reports documenting the superlative quality of SR-Ivocap in terms of precise fit, occlusion, and tissue compatibility.
Oskar Sykora, CDT, DDS, PhD/Elliot J. Sutow BS, PhD, Practical Assessment of a Continuous Injection Denture Processing Technique (SR-Ivocap) QDT Yearbook 1988
Thomas N. Tucker, DDS Middletown, N.J. Allergy to Acrylic Resin Denture Base (Journal of Prosthetic Dentistry, December 1981)
Clinical Research Associates (CRA) Newsletter. Denture Processing by Injection Molding (Volume 11, Issue 7 – July 1987)
The above denture was packed with the Ivocap method using clear acrylic in the reservoir. The clear area shows how much acrylic needed to be injected to compensate for the 7% shrinkage factor of conventional acrylic.
Clinical Research Associates:
“Research has verified improved dimensional characteristics compared to regular flasking. Vertical dimension of prostheses is not increased… Saves the dentist chair time because less after-seat adjustments are needed.”
– CRA Newsletter, Vol. 11, Issue 7, July 87.