click below
click below
Normal Size Small Size show me how
Liners & Bases (3)
Operative: Liners & Bases (Bases)
Question | Answer |
---|---|
The principal ingredient of the zinc phosphate cement powder is ........ | 1. zinc oxide (≥ 90%) 2. Magnesium oxide (≥ 8%) 3. silicon dioxide (1. 5 %) 4. bismuth trioxide (0. 1 %) 5. and other minor ingredients (0. 1 %) to alter the working characteristics and final properties of the mixed cement. |
The magnesium oxide is added to the zinc oxide to | |
The silicon dioxide is added to the zinc oxide to | |
The bismuth trioxide is added to the zinc oxide to | |
Tannin fluoride may be added to | provide a source of fluoride ions in some products. |
Since the H3PO4 solution absorbs water vapor ............ | the bottle of the liquid shouldn't be left open longer than necessary, the liquid that becomes cloudy or forms crystals should be discarded. |
What are properties of zinc phosphate cement? | 1. The ultimate compressive strength of this material is (117) Mega Pascal. 2. It is radio opaque 3. it is irritant to the pulp if applied directly in deep cavities. |
Since powder/liquid reaction of zinc oxide is exothermic, what should you do? | mixing on cool thick and clean cement slab is recommended as a cool slab will dissipate the heat and reducing the accelerated reaction speed that resulted from elevated temperature. |
The principal ingredient of the zinc phosphate cement powder is ........ | 1. zinc oxide (≥ 90%) 2. Magnesium oxide (≥ 8%) 3. silicon dioxide (1. 5 %) 4. bismuth trioxide (0. 1 %) 5. and other minor ingredients (0. 1 %) to alter the working characteristics and final properties of the mixed cement. |
The magnesium oxide is added to the zinc oxide to | |
The silicon dioxide is added to the zinc oxide to | |
The bismuth trioxide is added to the zinc oxide to | |
Tannin fluoride may be added to | provide a source of fluoride ions in some products. |
Since the H3PO4 solution absorbs water vapor ............ | the bottle of the liquid shouldn't be left open longer than necessary, the liquid that becomes cloudy or forms crystals should be discarded. |
What are properties of zinc phosphate cement? | 1. The ultimate compressive strength of this material is (117) Mega Pascal. 2. It is radio opaque 3. it is irritant to the pulp if applied directly in deep cavities. |
Since powder/liquid reaction of zinc oxide is exothermic, what should you do? | mixing on cool thick and clean cement slab is recommended as a cool slab will dissipate the heat and reducing the accelerated reaction speed that resulted from elevated temperature. |
The principal ingredient of the zinc phosphate cement powder is ........ | 1. zinc oxide (≥ 90%) 2. Magnesium oxide (≥ 8%) 3. silicon dioxide (1. 5 %) 4. bismuth trioxide (0. 1 %) 5. and other minor ingredients (0. 1 %) to alter the working characteristics and final properties of the mixed cement. |
The magnesium oxide is added to the zinc oxide to | |
The silicon dioxide is added to the zinc oxide to | |
The bismuth trioxide is added to the zinc oxide to | |
Tannin fluoride may be added to | provide a source of fluoride ions in some products. |
Since the H3PO4 solution absorbs water vapor ............ | the bottle of the liquid shouldn't be left open longer than necessary, the liquid that becomes cloudy or forms crystals should be discarded. |
What are properties of zinc phosphate cement? | 1. The ultimate compressive strength of this material is (117) Mega Pascal. 2. It is radio opaque 3. it is irritant to the pulp if applied directly in deep cavities. |
Since powder/liquid reaction of zinc oxide is exothermic, what should you do? | mixing on cool thick and clean cement slab is recommended as a cool slab will dissipate the heat and reducing the accelerated reaction speed that resulted from elevated temperature. |
If reaction speed is too of the zinc oxide is too fast, what will happen? | If reaction speed is too fast, so that setting will take place before sufficient powder has been incorporated and this resulting in a mixture with 1. a high residual acidity and irritation to the pulp 2. as well as lower mechanical strength. |
Water lost from the liquid ........................, while incorporation of water into the mixture will ................. . | delay the setting of cement, while incorporation of water into the mixture will shorten the setting time. |
Incorporation of maximum possible amount of powder into the liquid will give ..................... | a. better mechanical properties b. and reduces the amount of non-reacted acid. |
Mixing over a large area, incorporation small increments of powder over a large area of the slab | thus 1. dissipating the heat of the reaction and 2. permit a greater quantity of powder to be added and 3. smoother mix, 4. with longer working time 5. and less acidity. |
It's essential that the cement only applied on pulpal floors and axial walls why? | it should not be extended over any wall that extended to cavosurface margin, otherwise it will dissolve by time and leaving a gap. Retention grooves, slots locks and coves must be cement free. |
Two type of mixture consistency are made with Zinc-Phosphate cement: | 1) The thin or creamy consistency (luting) for cast work cementation. 2) Thick consistency used as a base because of the ease of manipulation. |