@@mohammedzzzz610 thanks, I specialize in orthodontics and don’t have any useful info on general or restorative dentistry methods.

That’s a good question. There are a few possibilities (from most likely to least likely): 1. On your digital design, the models have not been completely set on the print plate. 2. Your first few layers may not have had enough cure time to thoroughly stick to the print plate. 3. Your print plate may not have sufficient texture to allow the resin to adhere during the first few layers. 4. You may have printed with resin that has started to separate phases. If you stir the resin in the vat and you can see swirls, it needs to be mixed more. 5. You may have cured material on your FEP plastic layer. 6. Your resin may be old and possible less reactive to your light source. 7. Your reflector plate may be dirty if it’s a projector. 8. Your projector may not be powerful enough, or is getting old. This would be the sequence I would follow. Hope it helps.

Separation medium is needed when using stone models so the composite doesn’t break the cast, fortunately this problem doesn’t exist with printed models and you don’t need it. I print at 0.08mm, but I know other who will print as thick at 0.17 and have perfectly acceptable results.

You can spray with cooking spray to make it come off easier, but it’s not required.

@@davidjensen4957 Thanks! I've had the resin breaking off inside the retainer lately because it was sticking to the plastic. Never had that happen in the three years I've been printing and making clear retainers.

Thanks Umesh. The mirror tool would also work, but only for a contralateral tooth. The copy and duplicate is the most universal way I have found to add a pontic that can be placed anywhere.

Thanks! With resin models you will have no need for a separation medium.