Dental stone ?

[Dr Jizzler]

Could anyone recommend me a good quality dental stone for casting up denture impressions im currently using dentstone KD but would like something with more strength and better looking for my private work. Also what do people using for for pouring up their duplictae models we were using the dentstone KD as well but changed to plaster but I dont think that when it comes to sitting the final denture on duplicate model it has the right properties we have had a few come back loose and I think this may be the problem.

Sorry for the long post I like my models to go out looking nice and was wondering as well how other people view this do they just cast them up give them a quick trim or do they take their time and trim them as say a study model. Some of the models in my old laboratory where atrocious and I was ashamed to have to put my name to them I dont want this happening in my own lab and think that if they go out looking crap it reflects on you as a whole.

I'll stop typing now

 

[Clear Precision Dental]

We trim our denture casts on a Wehmer orthodontic model trimmer with dual wheels, coarse and fine. We box all of our impressions using alginate in magnetic boxing strips, and pour the master casts with vacuum mixed stone. The smooth surface looks good and any extraneous wax dripped on the base is easily removed. We also pindex the casts when mounting to the bases, and also use magnetic bases as the connection to the articulator. The pindex is more accurate when remounting than traditional index marks (for post-processing equilibration),and also allow the case to be quickly remounted to a different occlusal registration when needed (ie. mismounts or corrections noticed at wax trial insertion).

I will find some photos and post them...

 

[TheLabGuy]

Whip Mix Resin Rock.....works great for the dental office because they come in individual packets so the Assistants can't add too much water or powder (normally). The big thing here is to get a Resin Rock (because they have different rates) with the lowest expansion rate possible.

 

[JohnWilson]

We trim our denture casts on a Wehmer orthodontic model trimmer with dual wheels, coarse and fine. We box all of our impressions using alginate in magnetic boxing strips, and pour the master casts with vacuum mixed stone. The smooth surface looks good and any extraneous wax dripped on the base is easily removed. We also pindex the casts when mounting to the bases, and also use magnetic bases as the connection to the articulator. The pindex is more accurate when remounting than traditional index marks (for post-processing equilibration),and also allow the case to be quickly remounted to a different occlusal registration when needed (ie. mismounts or corrections noticed at wax trial insertion).

I will find some photos and post them...

I want to see the interface that is pindexed to the plaster. Are you putting the female in the model and the male pins in the plaster? I am trying to envision how you are doing this.

I have always been looking for a better more accurate way to remount to the articulator. Like you said often times when we index the base it never ever seems to fit as precise as when we splay it off the articulator.

 

[kcdt]

Are you referring to the small pindex that look like silver nailheads?
They have a short white plastic sleeve that glues into the drilled cast and the nailheads are imbedded in the plaster articulation.

Dr J.:
I box and pour impressions and I duplicate in silicone in small throwaway tupperwares. I find that a pour stone like flowstone works great. I also use it for the second pour when flasking.
For unboxed counter or cast RPD master, I go with resin rock.

 

[AJEL]

As a removable guy the only time to use a die stone is for flexibles. Zahns Gibraltar Base White looks so nice, Tinfoil Substitute separator works on it for processing PMMA or Vinyl, and the base stone will give the girls 10 min to gab & get the model right. I'm into consistency so I measure 30ml/100gm & let gravity help & don't flip when pouring alginates. Hydrocoloid is for duplicate, the duplicates are for brux appliances I can see the accuracy it provides. The best is to vac mix the hydrocal gypsum (hate to trim bubbles from my work.) I use something like the NEY magnets in my model bases to make a nice clean pin articulation ( never liked stickywaxing the cast to a pinless articulator.) Again I'm removable & deal with empty space where teeth need to be. C&B I leave to others except for a little "snap on smile" "party teeth" & those require expansion stone for Myerson acetal.

 

[araucaria]

Ask suppliers for samples and factsheets, they're usually always obliging

 

[Dr Jizzler]

Loads of advice I would like to see some pictures of the pindex models and how it works. I'll give the resin rock a go for privates and let oyu know how I get on its interesting that everyone has different methods of casting and use different materials.