| Observation |
Possible Cause |
Corrective Action |
| Incomplete injection |
Exceeding the working time |
The material should be injected in a "soft pack". A "snap set" stage is too late for injection |
|
Not enough acrylic |
Use more acrylic for your mix, up to the stated maximum in the directions for use. Make sure the metal sleeve window faces you so that you can monitor when the piston has bottomed out. Add more acrylic as necessary. |
| Tooth movement, "blow out" of plaster or cracked investment |
Using a "sloppy" or wet mix of plaster or stone. |
Use the appropriate powder/liquid ratio for stone or a mixture of plaster and stone. Do not use a "wet" mix of plaster. The strength may not be adequate. |
|
Excess investment |
Remove investment level with the surface of the flask. "Domed" investment may crack when the flask is placed in the injection unit and tightened. |
| Change in vertical dimension of occlusion |
The flask was not completely closed |
Make sure no debris prevents closure, tighten bolts, but do not over tighten. |
| Stainless steel brackets are bent and/or slip out |
Brackets have been bent. Most likely due to over-tightening. |
Attempt to straighten brackets or replace them. The allen bolts should not be tightened excessively. Make sure there is no debris keeping the flask open and then close the flask with the brackets and tighten the bolts just past finger tight. |
| Bolts and/or flask threads are stripped |
Over tightening |
Tighten bolts just past finger tight. If the flask is not completely closed at this point check for debris which may be preventing closure. |
| Denture Base Porosity |
Using a cure cycle other than recommended in our directions for use. |
Use recommended cure cycles. A 30-45 minute boiling cycle causes porosity in most cases. We do not recommend this cycle with Lucitone 199. |
|
Temperature not well controlled |
Check the temperature of the cure tank with an accurate thermometer. A variation of only a few degrees can cause porosity. |
|
Missing blue cap on the injection pressing device |
Make sure the blue cap is on the pressing device or leakage of denture base will cause loss of pressure. |
|
Liquid/powder ratio or gelation time |
Follow the manufacturer's recommendation for proper amounts of powder and liquid in the mix. Also, allow mix to gel into a soft but not sticky "dough" prior to injection. |
|
Loss of pressure during cure |
Check the pressing device for adequate spring pressure. Make sure that the pressing device is screwed on the injection insert adequately. |
