Materials Investment (8 Small F45 )

Front 1

SCT

-Ceramic Materials that used to Form a mould شكل الفراغ by Lost wax technique into which Metal is cast

-Tech used to make mould for Casting of restorations

-it is the Space, into which Metal will be cast

Back 1

-Investment Materials

-Lost wax

-Mould قالب

Front 2

Req the mcq only

-GR F45 Sufficient Strength at room temp

-GR F45 Sufficient Strength at high temp

-Is there Chemical decomposition

-GR F45 Sufficient Expansion

-GR F45 Sufficient Porosity

-Ease of divestment تكسيره : Should be مهمة

Back 2

-To withstand handling procedures

-to withstand impact force of Metal

-No مش بيتفاعل

-to compensate Metal shrinkage

-to allow escape of gases inside mould

-Breakable

Front 3

Read

Comp of Investment

Back 3

-Refractory material تستحمل حرارة عالية

هو دا اكبر نسبة

-Binder

-Chemical Modifiers (Additives)

Front 4

Component that can withstand high temp

-SCT

-MCQ Responsible for producing w achieved through w Most one make it

-MCQ Ex

Back 4

-Refractory material

-Thermal expansion... Displacive Trans... Cristoballite كريستو الحراق

-Silica موحدة في كل الأنواع

Front 5

Binder

-MCQ Binds SiO2 to Form

-MCQ F45 EXAM ESSAY Ex w Name of its Type of Investment

Back 5

-Coherent solid mass

-Gypsum Product افتكر ايام الشابتر دا(a hemi Hydrate) ... Gypsum bonded investment

-Ammonium Diacid PO4... PO4 bonded investment

-Na silicate or ethyl silicate.... Silicate bonded investment

Front 6

Chemical Modifiers (Additives)

GR Added

Back 6

To prevent oxi of metal in mould

عشان ميحصلش porosity

Front 7

Class of Investment acc to MCQ what w list

Back 7

Binder

-Gypsum bonded أسهل استخدم عشان خدت الشابتر دا

-PO4 bonded اكتر واحد استخدام

-Silicate bonded لا يستخدم عشان من غير اختصار

Front 8

Gypsum

-يستخدم لمين مبدأيا MCQ

-Comp :

A)MCQ Refractory material متفق عليه قبل كدا

B)MCQ Binder متفق عليه قبل كدا

C) Chemical modifier : List w GR added each one

-Manipulation :

A) Mixing افتكر ياسطا الشابتر افتكر :what Should be avoided w By

B) Prep of wax Pattern : MCQ What should be applied to wax w GR

C) Investing wax Pattern مهم :

1)GR Casting Ring lined with liner

2)GR Done under vaccum (no air)

D) Heating mould : mould is then Slowly heated to max kam w GR

-Prop

A)Dimensional Changes :

1)GR Setting Expansion افتكر الشابتر القديم

2)MCQ Factors affect degree of Setting Expansion افتكر الشابتر القديم

3)GR Hygroscopic Expansion

4)MCQ F45 Factors on Hygroscopic Expansion

5)Factors aff Thermal Expansion

6) Shrinkage : when heating what occ w which Type of expansion

B) Strength :

1)MCQ Overheating >700 C cause

2)MCQ Further Heating >1000 C cause

3)MCQ EXAM Possible outcomes from decomposition w Causing

C) Porosity : present or not

Back 8

-Gold alloys فقط

C)

-NaCl w Boric Acid... To ⬆️cte

-charcoal الفحم شاركول (reducing agent)... عشان اللي احنا عارفينه

Prevent oxi of metal in mould

A) Air incorporation... Adding Powder to liquid

B)

1) Surfactant... To Enhance wettability (Adhesion) as wax is Hydrophobic

C)

1)to Facilitate mould expansion by Cushing action زي الأسفنج

2)To prevent air trapping on Surface of Pattern امنع الفخ

D) 700 C... To ensure that wax is completely burnt out and induce thermal expansion

A)

1)due to Outward thrusting action

2)

-W/P ratio (Indirect)

-Size of Silica (Direct)

-Mixing time w rate (Direct)

3)due to presence of Gypsum as Binder

4)

-W/P ratio كلام معاد

-Size of Silica كلام معاد

-Water Temp

-Water Role

-Silica Content

-Time of immersion

-Presence of Casting Ring

-Age of Investment

5)

-Temp

-W/P ratio نفس العلاقة الوحشة فوق

-Silica content

-Type of Silica

6) dehydration... Thermal Expansion

B)

1)Reduction of CaSO4 Binder

2)decomposition of Investment

3)SO2 w SO3... Brittleness w Porosity w Corrosion

C)عندها

Front 9

EXAM Factors of Hygroscopic

2)Water Temp : Direct or Indirect

3)MCQ Water Role كمية المياة اللي هتتحط : -amount of water added Direct or Indirect

-Max degree of expansion with least quantity of water req to produce it.. SCT MCQ F45

4)MCQ F4555555 Silica Content (Silica /Binder ratio) : Direct or Indirect w eff on Strength

5)Time of immersion : Delayed immersion lead to lower or higher expansion

6)Presence of Casting Ring : inc or dec expansion

Back 9

2)Direct

جدعنة مني الحرارة تزيد يسييح فا يعمل expansion

3)

-Direct

- Critical Point (Saturation)

4)Direct.... Dec

5)lower

6)dec

Front 10

Factors of thermal expansion

-MCQ F45 Silica Content : Relation

-MCQ Highest thermal expansion

-MCQ Lowest thermal expansion

Back 10

-نفس علاقة اللي فات Direct

-Cristoballite

-tridymite

Front 11

PO4 Bonded investment

-MCQ other name

- Comp

1)Refractory material متفق عليه

2) Binder متفق عليه

3)Chemical modifier المتفق عليه في المقدمة

-MCQ EXAM Setting Reaction : GR Increased strength during heating (at high temp)

-Manipulation :

1)MCQ EXAMPrep of wax Pattern : Which rings used

2)Investing wax Pattern : GR done under vaccum زي الاول كدا متفق عليه

3)Heating mould : مالوش ايه

-Prop

A) Dimensional Changes زي الاول باختصار متفق عليه

B) Shrinkage مهمة فشخ : acc by evolution of

C) Strength :

1)GR set material increases in strength during heating

2)MCQ EXAM For Base mixed with water or silica sol

3)MCQ EXAM For Gold mixed with water or silica sol

D) Porosity عندها بردو زي الاول

Back 11

-Universal بتاع كله

- Due to reaction between Ammonium diacid PO4 w Silica to Form Silico-phosphates

1)Plastic or Rubber not Casting rings

3)Limit

B) Ammonia NH3

C)

1)Due to formation of silico-phosphates

2)Silica Sol

3)Water

Front 12

Silicate bonded investment

-يستخدم ليه

- دا لما ينشف يعمل expansion ولا shrinkage

-Comp

A) Refractory material : متفق عليه

B) Binder : متفق عليه

C) Chemical Modifiers : متفق عليه في المقدمة

-Setting Reaction

A) Stages

B) On heating there is loss of

C) NB : Disavd

-Manipulation : heated up to

-Prop

A) Dimensional Changes :

1) Which type of expansion w GR

2)Shrinkage مهمة which Type w during which stages

B)Porosity :

1)Present or not

2) GR Artificial Venting مسام صناعية is necessary

Back 12

-Base فقط

-Shrinkage

وحش فشخ

A)

- Hydration Hydrolysis

-Gelation

- Drying

B) Alcohol w H2O

C) flammable w expensive

ممكن يتحرق و غالي

-1200 C

A)

1)Thermal only... Due to Very large silica

2)Setting... Gelation w Drying

B)

1)Tightly packed (negligible)

متكلبش

2)to allow escape of air to avoid back pressure porosity

Front 13

Compare

-Strength

-Ring

-Porosity

-Expansion

-Metal

Back 13

Front 14

Blue Box

GR

-Gypsum bonded w PO4 Bonded mixed with H2O, can used for Casting Au Alloys

-PO4 bonded Mixed with silica Sol w silicate bonded used for Casting base alloys

Back 14

-as it can withstand their melting temp w total expansion is Sufficient to compensate for its shrinkage

-As they can withstand their high melting temp w compensate for their high shrinkage