This video demonstrates fabrication of a silicone model, made from Mach II die silicone and bite registration material. This type of silicone model is a daily occurrence in my practice as I use them for fabrication of anterior bite plane appliances, indirect provisionals, and any other time I need a quick way to get a highly accurate model.
Fabrication Steps:
- Alginate Impression
- Cut tip of the Mach II back 4-5mm
- Inject Mach II material in the impression up past the gingival margins of the teeth.
- Inject bite registration material up past the lingual flange of the alginate
- Turn over and set against a flat surface to create a stable base.
- Separate as soon at the bite registration material is set.
Very interesting technique, Lee. Thanks for sharing. Although not directly related to your topic of the day I wonder if you might elaborate further on how you use the silicone model to fabricate provisionals? Do you simply use a cuttersil mould on the model itself?
Vivian,
If you are going to use it for a provisional make sure you flip it over and have the flat base. the model is flexible so if you hold it in your hand it may flex and distort. You do not need any die separator or lubricant. Simply try your provisonal matrix, silicone or copyplast on the silicone model, and trim the flanges if you need so it will seat all of the way. I usually cut a notch between the centrals and then with it tried on scribe a line around the model with a sharpie at the edge. Then fill the matrix with bisacryl or acrylic, seat over the model, the model is on the counter or bench as you seat, make sure you seat the matrix until it is lined up with the sharpie line you created so you have not left it high. Hold in place until completely cured. Unlike in the mouth you do not have to remove in the flexible stage. Also, bisacryl is accelerated by heat, so without body temperature the material will take longer. Read the instructions for the material you use on bench cure times. Once fully cured remove the matrix, and the model and provisional should separate easily, and you can wiggle and flex the model to slide them apart. Now you can trim the provisional and even put it back on the model to polish.
Thanks for the detailed description Lee, I look forward to trying this out soon. I have a four unit jacket veneer case coming up soon and I think it would make life so much easier if I could use this technique to fabricate better provisionals. I’ll let you know how it goes :)
Dear Leeann:
Thank you for your blog. With this technique for making temporaries, are you using the identic syringe from dux dental to pick up the margins? Or are you just taking the impressions of the preps with the standard alginate technique?
Thanks,
Simon
Simon,
The alginates for this technique can be done either by using the Identic syringe made for hydrocolloid to inject around the margins, or what I do is put some regular alginate into a monoject syringe and place around the margins prior to seating the tray.