Triple tray use it at your peril!! It’s quick and cost effective but will cost heavily when fitting your restoration.
It sounds like a great idea!! Because you can take both upper and lower impressions and a bite registration all at the same time! Sounds like a great idea! Right?
But is it?
As the patient bites down to engage the impression material when using triple tray, they may bite the thru the impresion materialand onto the tray itself in the process distorting the shape of the tray, the impression material sets and the patients opens there mouth, the pressure distorting the tray is removed and the tray returns to it original shape, the impression material which is attached and supported by the tray distorts due to the tray returning to its original shape.
This resulting elastic distortion in the impression may cause any restoration made using this information be prone to not fitting at all or having loose or tight proximal contacts or being high in the bite or short of the margins or baggy or too tight. Inlays and onlays are the most prove to not fitting when triple tray is used.
Bite registration from triple tray tend to be inaccurate due to the thickness of material the patient is biting into
Post and cores are also very prone to impression distortion when using triple tray
So the time that was saved using triple tray is lost at the fit appointment when it takes lots of extra time to fit and need to adjust heavily or re-imp.
Also the laboratory only receives 1/3 the dentition or at best 1/2. Making articulation often incorrect and time consuming.
The best way to minimise these problems is to use:
Metal impressions trays or special trays they are very rigid and don’t distort
Full arch upper and lower impressions even for and MO inlay
Bite registration taken using a rigid material in low thickness
restoration will fit better and save you time