Prosto lab 2 After lab 1 and finishing the examination and we approve the case we must do several things like: selecting the tray then select the impression material either compound or alginate then finally make the primary impression ** Tray selection depend on situation and on the case either metal or plastic either dentate or edentulous so take it in consideration ((As I remember dr said that metal is always used for compound while plastic perforated is for the alginate))

*** Important notes according to making primary impression:1 dont use dentate tray for edentulous patient due to it is made with some space for the teeth / will lead to problem recording the sulcus / uneven thickness / there will be an increasing in the amount of impression material that we are going to use

2 difference between the edentulous and dentate tray resemble in the shape/ size / use / perforations / space

3 alginate retain in tray by 2 things adhesive spray / the perforations of the tray that the alginate penetrate which make it firmly attach to the tray

4 location of dentist while taking a lower impression must be in front of the patient but for the upper jaw he must stand behind the patient

5 to make sure that compound is evenly softened from all areas you need to keep kneadling it while it is soaked in the hot water

6 we use the goose while making the impression material ready so it dont stick to the base of the rubber bowel

7 before we take an impression and after we put the compound in the patient mouth we must soaked it in the hot water just to ensure that it is still soft and capable of recording all the details without being set before we do that

8 to record the best details of the sulcus and labial details you must firstly make the handle of the tray just under the patient mouth and press firmly on the tray while it is in the patient mouth

9 knowing that the material is set is very important thing coz if we didnt knew it we might take the tray out while the material is not set yet so take in consideration that if u want to speed up the set of material for compound you must use the air in the 3 in 1 and to know if it is settled you can depend on 2 things first the setting time that is wrote on the package of the material or the fingernail test which you press y your fingernail and if there was no trace then it is set

10 face mask is needed when you are working with alginate coz alginate can precipitate in the lungs so be aware

11 adhesive material is used for retention of the alginate the drying time is settled by the manufacturer company but the avg is about 10 min to be dry and finally dont put alginate over a wet surface of adhesive material coz it will work as separator not as adhesive as dr mention

12 utility wax is very important coz we depend on it in increasing the length of a tray to be suitable for taking impression specially for the stock trays coz they are small in size and may not cover the surfaces we need also they help in preventing any excess of the alginate from going in patient mouth and prevent tearing or float out of alginate

13 we use utility wax in the upper tray mostly in these site: premaxillary / distal areas if short / lingual pounch on the other hand for lower trays we use it in: buccal shelf's / distal area (distobuccal) / lingual bounch

14 the alginate powder pack must be agitated properly coz it contain light and heavy components so that allow us to mix them better

15 liquid is added before the powder to make mixing easy

16 when u do disinfection which is important compound can be socked in a disinfection material coz it can handle the moisture and the water while alginate we use only spray disinfectant material and dry it with a goose after that to avoid any distortion in the dimensions

17 pouring time for the compound is in max 1 hour to avoid the lost of heat which can result in distortion of the work but for the alginate it is as soon as possible to avoid the loss of the moisture that we use it to prepare it to avoid the loss of dimensions

18 to remove any air bubbles from our material we must do 2 things first use vibrator scnd put the plaster in inclined way from ant t post

19 we add lump once we pour to attain Wight that press over and make plaster goes in all directions

20 in deepest part of the base the thickest part is max 2 cm

21 ridge orientations is parallel to the base of the cast

22 water is used with trimming to avoid the dust / reduce the heat that is produced of friction and finally to produce sthng that last for long time

Excuse me for any spelling mistake