organization - university of jordan dentistry ......organization it was made by a group of students...

Organization

It was made by a group of students from 2013 dental batch in the

University of Jordan.

Idea by: Afnan Najem

Work team members:

Batool Alsa'aydeh, Abeer Al-Hamdan, Mos'ab Altawarah, Dania Tafesh,

Majd Olimat, Tasneem Tayseer, Farah Albanna, Duha zahran, Aya Al-

Ayyat, Leen Mahasneh, Mira Salem, Zainab Al-Zo'bi and Murad Toubeh.

Designed and fully reviewed by: Abeer Al-Hamdan

References

All included information are written based on students’ notes,

lab and lectures slides, and Internet.

1

Prosthodontics lab tools

Stock plastic trays "edentulous patient"

Wax knife

Plaster knife Lubricating material

Lacron carver

Plastic spatula

2

Base former set

Rubber bowel

Acrylic bur HP steel flame shape

gauze

Syringe 50cc

Hot plate

Alcohol flame

Teeth set one layer complete set

3

Average value articulator

Afnan Abd-alhade Najem

By

1st exercise: 1st section: Primary impression 2nd section: primary cast

By: Afnan Najem reviewed by: Mos'ab Altawarah

5

INTRODUCTION

Impression compound is a thermoplastic material ,that used after being heated and can be used again

and again .it's cheap material ,mucocompressive ,very viscous , Once set it becomes rigid and lacks

elasticity. It's Ideal for primary impression FOR edentulous (but if you face a sever undercut then we

turn to another choices)

Composition

47% Thermoplastic material(natural or synthetic resins or waxes)

determines the softening temperature.

50% filler(talc) gives body by increasing viscosity, reduces thermal contraction

3% Lubricant(stearic acid) improves flow properties

FIRST EXCERSICE: 1ST SECTION: PRIMARY IMPRESSION

In this exercise we are going to record the primary impression for an edentulous jaw using the following

tools .

TOOLS AND INSTRUMENTS

Working sheet all labs not to dirt the bench.

Gloves all labs not to dirt your hands.

Lab coat all labs not to dirt your clothes

Trays many sizes to record the impression.

Impression compound an impression material given in the lab.

Vaseline to lubricate between the impression compound and the jaw.

Gauze 4*4 to carry the impression compound while softening in hot water.

Safe electrical heater to heat water to soften the compound.

thermometer (100 grades)

Rubber Bowel

Wax knife


6

THEORY AND PROCEDURE

I.TRAY SELECTION

Choose the suitable stock tray which is a curved tray and not too loose nor too tight but 2-3mm larger

than the edentulous jaw (giving the space for compound).

II.SOFTENING OF IMPRESSION COMPOUND

Heat water to 55-60 Celsius to soften the impression compound. Put

1 and1\4 of a piece of the red impression compound (for the upper)

and 3/4 of piece (for the lower) on 4*4 gauze then put them 5

minutes in the hot bath. Fig1-1

III.PREPARE TO TAKE IMPRESSION

Put Vaseline on your hands then Put the impression compound on

the tray and spread it with your fingers to cover all parts of tray. Ensure equal thickness and nothing to

be shown from the tray. (see notes 8 and 9).

Loosely, Cover the tray with gauze again and return it back to the hot bath for a minuteto resoften it

since it becomes rigid by time.

V.POSITION OF DENTIST WHILE TAKING IMPRESSION

The best position for the operator To apply the tray FOR UPPER

IMPRESSION is standing between 9-12 o'clock . fig1-2

VI.TAKE IMPRESSION

Insert the tray from back to front, ensure centricity by keeping the

handle of the tray at a line with the nose. (never ever insert the tray

from front to back, because you will push the excess to the

oropharyngeal area).

Keep pressing gently on the tray and by a piece of wet cotton cool

down the impression compound in the tray from outside.

Wait the compound to cool down and become rigid, then remove it in one movement; not gradually

(watch out! Don't remove the tray immediately after the outer compound become rigid because the inner

part will still be soft, that’s why you should wait about 1 min after the outside compound become rigid).

IX. PRIMARY CAST

Pour the primary cast AS SOON AS POSSIBLE after recording the impression

Fig 1-1

Fig 1-2


7

NOTES AND ADVICES

1. To reuse Metal trays you need to sterilize them.

2. You need to break down the impression compound cake to pieces because it has a low thermal

conductivity.

3. Use Vaseline on hands to carry impression compound because it is very sticky.

4. Use Vaseline in the phantom head jaw instead of saliva in human jaws.

5. Don’t heat the water more than 55-60 because that will make the impression compound more

sticky and it will become granulated because of stearic acid evaporation.

6. Don’t heat the water less than 55-60 that will make the impression compound rigid.

7. Don’t put Vaseline between the tray and impression compound, this will reduce retention of

impression material.

8. Make a ball from impression compound then spread it on the top of the tray to record maxillary

impression.

9. Make a hotdog shape from impression compound then spread it on the top of tray to record

mandibular impression.

10. Model should be poured AS SOON AS POSSIBLE after recording the impression because impression

compound is not dimensionally stable and distort easily.

EVALUATION CRITERIA

Exercise Number 1

Primary Impressions for Complete Dentures.

1.Instruments and Materials: Arrangement and Cleanliness_____________________ 2/10

2. Stock Trays Selection________________________________________________2/10

3. Position of the Patient and the Operator___________________________________2/10

4. Impressions

• Tray Centricity___________________________________________________2/10

• Wrinkles, Foldings, and voids_______________________________________2/10

• Tray shows through the impression material____________________________2/10

• Necessary anatomical landmarks (most important among all)

1. Lower Impression:_______________________________________4/10

a. External Oblique Ridges

b. Mylohyoid Ridges

c. Vestibular Reflections

d. Frenal Attachments (lingual, labial, buccal)

e. Retromolar pad areas

f. Postmylohyoid Fossae


8

2. Upper Impression:______________________________________4/10

a. Alveolar Ridge

b. Palate covered as far as the vibrating line

c. Foveae Palatnae

d. Hamular Notches

e. Vestibular Reflection

f. Tuberosity Sulcus Frenal Attachments (labial, buccal)

Total: _____________ /100

HELPFUL VIDEOS

https://www.youtube.com/watch?v=wLswdj1tfyg

take your breath and go ahead to the 2nd part…

FIRST EXERCISE: 2ND SECTION: PRIMARY CAST PRODUCTION

Gypsum is a naturally occurring white powdery mineral, chemical name is Calcium Sulphate Dihydrate

"CaSO4 . 2H20 " . gypsum product is mixed with water to get the flowy material that is used to pour the

model. Powder: water ratio varies according to the type of gypsum product used. In this lab plaster of

paris is used to pour the mold and it’s P:W ratio will be 100gram : 55cc

Gypsum products:

Plaster of Paris ( POP ) : White "good for primary cast"

Dental stone : Yellow "good for master cast"

Die stone : Colored

Gypsum products are used for production of models and dies. They are Composed of calcium sulfate

hemihydrate, upon mixing of water, calcium sulfate dihydrate is produced.

Other components are added like Potassium sulphate which is an accelerator and Borax which is a

retarder for the setting reaction.

CaSO4·2H2O CaSO4·½H2O + H2O

Gypsum gypsum products + water

Plaster of Paris is produced by calcination (heating of gypsum at 120°C) to drive off water. Plaster of

paris has a porous and irregular particles.

110-130˚C (Plaster or Stone)

https://www.youtube.com/watch?v=wLswdj1tfyg


9

Dental stone is less porous and has more regular particles, produced by calcination under steam

pressure in a closed container.ST EXCERSICE: 2nd SECTION: CONSTRUCTING CASTS FROM THE

PRIMARY IMPRESSIONS

In this exercise we are going to pour a model from the impression we had taken using plaster of Paris.


your impression

rubber bowl

mixing spatula

plaster of Paris given at the lab

trimmer found in plaster room

syringe 60cc and plastic cup

Wight balance


I. MIX GYPSUM PRODUCT

Measure 55cc water using a syringe, pour water in the rubber bowl. Weight a 100g gypsum product

"plaster of Paris " (it is approximately a full filled plastic disposable cup).

Gradually add powder to water in the bowl and mix them together till you have a creamy mixture. {it is

BETTER to mix them on the vibrator this will aid in reducing porosity and air bubbles formation}.

IV.POUR THE IMPRESSION

On the vibrator put the tray with the impression inside and start pouring the plaster gradually in small

increments from back to front, allowing the material to flow and cover all the fitting surface of the

impression. Then add in larger increments.

V.BASE OF THE CAST

a. On a piece of paper put the remnants of plaster; to make the base of the cast.

Make hashtag(#) shape on the plaster poured on the impression and then put the

impression with the gypsum on it at the top of the plaster base which you already put it

on a piece of paper and press gently then tidy up the edges with your fingers wetted

with water.


10

b. Using a base former, fill the base former with plaster

then put the poured impression on it. this will result in

a more good looking base that do not need much

trimming.

VII.REMOVE THE IMPRESSION FROM GYPSUM

To remove the impression from the gypsum put it in a hot water bath

40c, this will make it easier to separate them from each other.fig1-3

VIII. TRIMMING OF THE CAST

Trim the cast sides to become vertical and at right angle to the base of

the cast. Be aware not to trim the land area.

Proper thickness of the cast should be not less than 1–1.5 cm in the

thinnest parts. Fig1-4

NOTES AND ADVICES

1. Too little water, too dry and unworkable mix.

2. High water/powder ratio retards setting, increases porosity

and reduces compressive strength.

3. Mix with vibration to reduce porosity.

4. Don’t leave any plaster over the tray.

5. after trimming the base, when you put the cast on the flat surface it must be stable and

not rocking.

EVALUATION CRITERIA

The Primary Cast Criteria for Acceptability

1. Accurate details and faithfully represents the oral anatomy.

2. The surface of the cast hard, dense, and free of voids and bubbles.

3. The edentulous areas extend to their physiologic limits and land area is preserved.

4. The sides of the cast are vertical and at right angle to the base of the cast.

5. The base must be flat, straight, and 1-1.5cm think in the thinnest area.

6. Tongue space flat and smooth.

7. Land area present all around the cast (3-4 millimeter width).

Fig 1-3

Fig 1-4


11

HELPFUL VIDEOS

https://www.youtube.com/watch?v=G_1NWimPF2w

QUIZ

Q1. Mention two criteria you use when selecting a stock tray for a primary impression using compound for

the mandible?

Q2.what is the composition of impression compound?

Q3. Mention two advantages and two disadvantages for impression compound?

Q4. What is the origin and insertion of masseter muscle?

Q5.what are the main types of gypsum product?

Q6.how gypsum product properties changes from the first to the fifth type?

https://www.youtube.com/watch?v=G_1NWimPF2w

Mos'ab Tawarah

By

2nd exercise: Special tray construction for CD

By: Mos'ab Tawarah Reviewed by : Batool Alsa'aydeh

13

2ND EXERCISES SPECIAL TRAY CONSTRUCTION FOR CD

The special tray is a custom device that is prepared for a particular patient, used to carry, confine and

control an impression material while taking a secondary impression.

In this exercise we want to get a negative image of the primary cast in the form of a tray.


Two pens with different colors.

Ruler.

Separating medium (i.e. Vaseline )

Wax knife.

Acrylic resin (light-cured) sheet. (provided by the lab instructor)

Acrylic bur.

Light Cure unit. (found in the lab)


I. DETERMINING THE OUTLINE OF THE SPECIAL TRAY ON THE PRIMARY CAST.

A- draw a line runs the full depth of the sulcus (labial and buccal

sulcus and through hamular notches across vibrating line in the

maxillary cast) and (labial, buccal and lingual sulcus in the

mandibular cast) "blue line in the fig. (2-1)"

B- draw a line shorter than 1st line by 2mm (toward alveolar crest)

with a different color. "red line in fig. ( 2-1 )." In the maxillary one,

the two lines merge at posterior palatal seal area (most posterior

part.) this line is to provide room for frenal attachments.

Fig (2-1)


14

II. FINAL PREPARATION OF THE CASTS.

Lubricate cast by petroleum jelly "Vaseline" or any other separating medium. Avoid over lubrication.

III. ADAPTATION OF THE ACRYLIC RESIN

A. put the sheet over the cast and adapt it to register any details and to block-out undercut. (make sure

to have one thickness of the sheet over all areas).

B. Trim line in vestibules and posterior palatal seal using wax knife.(at lower line or between the two

lines but don't extend to the upper line or even reach it.)

HANDLE ADDITION

(from excess pieces) create a small vertical handle that doesn't push the vestibule. (add before curing). Fig (2-2); maxillary cast & fig ( 2-3); mandibular cast.

C. then, we put the cast in the light cure box for 5 minutes.

IV. FINISHING

take the tray out of the cast and trim the edges all around using the acrylic bur to make it smooth then

retain it to the cast to adjust the height of the tray (watch out, you have to reach the 2nd line by the

trimming , not less not more).

AUXILIARY

HANDLES

Fig ( 2-3 ) Fig ( 2-2 )


15

EVALUATION CRITERIA

Smoothness of the edges so, you have to trim all the sharp edges and protuberance (نتوء).

(most important criteria among all)

Height of the tray (to 2nd line, not less not more).

Shape of the handles. ( it must be vertical)

HELPFUL VIDEOS

https://www.youtube.com/watch?v=VQGymTcWDXw Maxillary

https://www.youtube.com/watch?v=kfpxOdPmm9w Mandibular

QUIZ

What is/are the material(s) that can be used in construction of the special tray?

Mention 4 of criteria that should be found in the primary cast to make special

tray. (you'll find a lot of criteria in the lab's slides, back to them)

https://www.youtube.com/watch?v=VQGymTcWDXw

https://www.youtube.com/watch?v=kfpxOdPmm9w

3rdexercise:

Secondary impression

and Master cast

construction

Dania Tafesh

By

By : Dania Tafesh Reviewed by: Batool Alsa'aydeh

17

THIRD EXCERSICE: SECONDARY IMPRESSIONS ,MASTER CASTS AND RECORD BASES

In the lab we will do beading and boxing for the secondary impression and learn theoretically how to

produce a master cast.


Secondary impression (you will be given a

ready-made one).

beading wax

Boxing wax

Wax knife (you could use it to cut or melt

some wax)

Ruler

Lighter


1- at first support the lingual surface of the secondary

impression -handled to you- with wax and that is achieved by

cutting a triangular shape wax to accommodate the shape of

the lingual area .

NOTE: make sure that it is thick enough so that light doesn’t

go through the wax clearly. Fig (3-2)

Fig (3-1)

Fig (3-2)


18

2- Now, take the beading wax and put it

around the entire periphery and lute it at the

noncritical edge. Fig (3-3)

NOTE : it must be:

I-3mm under the flanges

2-3mm in width

(This will be the land area later)

4- Enclose the impression by building up

vertical walls using boxing wax to produce the

desired size and form of the base of the cast

and preserve details of the impression.

Note: the highest point of the impression

must be about (1.5-2cm) from the highest

point of the boxing wax. Fig (3-5)

5- Lastly, for stability you need to make small

legs from wax and stick it at the bottom of the

impression to look like a table.

BEADING AND BOXING OF A MAXILLARY IMPRESSION

The same steps of the lower impression, but it

doesn't have a lingual area. Fig (3-6)

Fig (3-3)

Fig (3-5)

Fig (3-6)


19

PRODUCTION OF THE MASTER CASTS

Actually in this lab you won’t make a master cast and they gave us a ready-made one.

But you need to know the method because you will do it in the 4th year.

Rules for handling gypsum products:

Always use a clean mixing bowl and spatula.

Always add the powder to the water never the water to the powder.

Always weight the powder and measure the water.

Spatulate thoroughly incorporating all powder from the sides of the bowl with the

spatula.

Always use a vibrator to eliminate air pockets.

Never add water to a mix which has been started with too much powder.


clean bowel

plastic cup

Syringe

spatula

Ruler

Pencil

Cutter

lacron knife , plaster knife , wax knife


I. DENTAL STONE MIXING AND POURING

for the master cast we use Dental stones ( type 3) and here we use 20 -30 g of every 100

ml of water, then mix them very well and apply them on the boxed impression after

applying a separating medium ( i.e. Vaseline) but make sure that you are working above

the vibrator. Fig (3-7),(3-8)


20

II. SEPARATING IMPRESSION FROM MASTER CAST

After that we separate the master cast from the impression using hot water to melt the

green stick that was found around the impression. Fig (3-9)

And now the master cast is ready. Fig (3-10)

FINISHING: TRIMMING AND INDEXING

The last thing you have to make is the final Preparations of Master Casts and that

includes:

• Trimming of the bases of wet master casts.

• Indexing the master casts. ( these step will aid later in flasking)

2 3 1

Fig (3-7) Fig (3-8)

Fig (3-9) Fig (3-10)


21

CARVING OF THE POSTERIOR PALATAL SEAL AREA

Note: try to carve the posterior dam area by following the curve of the lacron knife and avoid

over carving.

This step will be explained in more details in the next exercise.

NOTES AND ADVICES

As mentioned before that you will be handled an already made impression but you

have to know how to do it for the 4th year.

And you can do it by border molding of the special tray using a green stick and

then put the impression material and put it in the patients' mouth until it is rigid

to ensure the seal.


22

There are many reasons for beading and boxing the secondary impression :

1) To preserve land area and border preservation.

2) To reduce the trimming time of the master cast and this will improve the master cast’s

properties since it reduce exposing the cast to the slurry water.

3) To get smooth walls.

4) the gypsum product that we use in the secondary impression has a low viscosity, and if

we don’t have walls around it will flow down, so we need something to hold it in a place

Why we use dental stone??

Because it gives finer details.

we can use silicon or any rubbery secondary

impression as an impression material but

beading and boxing are done using alginate at

the bottom and cardboard.

EVALUATION CRITERIA

well sealed

space representing the thickness of the base

cleanliness of the impression

beading on non-critical edge

cleanliness of the work

stability

Make sure that you stick the beading

wax stick firmly on the impression

then add the boxing wax because if

you don’t do this the whole work will

fail.


23

HELPFUL VIDEOS

https://www.youtube.com/watch?v=yANJXx3roUU .

QUIZ

Q1. Before pouring a working impression “secondary imp. ", you carry out beading and boxing so

what are the advantages of this step?

Q2.what are the objectives of border molding?

Q3.mention 2 materials can be used to make secondary impression in patient with severe bony

undercut?

https://www.youtube.com/watch?v=yANJXx3roUU

4th exercise: Fabrication of the maxillary occlusion rim

Batool alsa'aydeh

By

By : Batool Alsa’aydeh Reveiwed by : Abeer Al- Hamdan

25

FOURTH EXCERSICE : FABRICATION OF THE MAXILLARY OCCLUSION RIM

Occlusion Rims: are occluding surfaces built on record bases for use in recording maxillo-mandibular

relations and in arranging teeth.


Maxillary record base on master cast.

A sheet of base plate wax.

A sheet of Light cured acrylic resin.

The Hot plate, wax knife and lacron carver.

A Ruler and a pencil.

Acrylic bur.

A Lighter.

Rubber bowel filled with water.


I. MARK GUIDELINES ON THE MASTER CAST

Using a pencil or flowmaster colors mark the following things:

1. Incisive papilla (bisecting anteriorly)

2. Median palatine raphe (bisecting posteriorly)

3. Line bisecting the residual ridges extending it posteriorly fig 4.2.

4. Maxillary tuberosity fig4.1

II. CARVING THE POST DAM AREA

Soft tissues along the junction of the hard and soft palates on which pressure

within the physiologic limits of thetissues can be applied by a denture to aid in

the retention of the denture.

Fig (4-1)

Fig (4-2)


26

Post dam area should be measured and carved based on the patient records but in this exercise it

will be carved approximately based on average records but keep in mind that these measurements

are not fixed.

Locate post dam area roughly 2mm anterior to posterior palatal seal line.

With your lacron carver, dig to a depth approximately equal to 1-1.5mm. (keep the tip of the lacron

carver in a posterior position so that you will carve more posteriorly)

The post dam area is shallower anteriorly than posteriorly.

III. FABRICATION OF ACRYLIC BASE

1. At first add a separation media on the master cast (example: vasiline)

2. Put the acrylic sheet and extend it to the full depth of sulci by applying gentle pressure without

thining the acrylic sheet (you may use an eraser to do so because your fingers are tipped(

3. Put the master cast with the acrylic sheet on it in the light cure unit for 7-10 mins so

polymerization of MMA monomers take place. (revise the mechanism of polymerization of acrylic)

4. Using the acrylic bur smooth out the borders of the acrylic base and make some indentations along

the crest of the ridge (to maximize the retention of wax on it later on).

IV. WAX RIM FORMING

1. Light up your flame, and start heating the wax from the edge and roll it, then heat and roll

again. Repeat this until the whole sheet is beautifully rolled. Fig (4-4)

Fig (4-3)

Fig (4-4)


27

2. Bend the wax roll to simulate the shape of the residual ridge.

3. Apply the wax roll on the base, exactly over occlusal part of the scratches you already made.

V. SPREADING AND SHAPEINING OF THE WAX RIM

1. start spreading a part of the wax over the labial surface in a water fall motion, starting from

the anterior surface of the wax toward the sulcus.

2. use the heated hot plate to flatten the occlusal surface of the wax rim.

VI. LABIALY ORIENT THE WAX RIM

take the base with the wax out of the cast and start creating your labial inclination using your well

heated hot plate. Take a look at Fig (4-5) & fig ( 4-6 ).

VII. ADJUST THE HEIGHT AND WIDTH OF WAX RIM

start adjusting anterior and posterior vertical lengths and horizontal widths. Table ( 4-1) -includes the

measurements taken from the land area toward the upper edge of the wax rim- , fig ( 4-7) & fig ( 4-8) .

Table 4-1

Length Width

Anteriorly 22 mm 5-6 mm

Posteriorly 18 mm 8-10 mm

Fig (4-5) Fig ( 4-6)


28

X. SMOTHEING

after the final adjustments for the length,

width and labial inclination , smoothen the

labial surface gently using the hot plate.

After smoothening the surfaces, dip the rim in

the rubber bowel that is filled with water and

start smoothening the lingual surface using the

wax knife. (this prevents ruining your wax rim

by the wax knife ).

finally, cut the posterior borders ( in an

inclination) of the wax rim to a level before

reaching the maxillary tuberosity. Fig ( 4- 9)

NOTES AND ADVICES

1- Avoid flattening the acrylic resin too much so it won't become weak or break down later on.

2- Avoid over deepening of the scratches on the acrylic base, so it won't reach the cast.

3- Avoid using the wax knife on a hot wax rim, as its sharp edge would cause deformities that are hard

to correct. Always use it on a cold surface.

3- Keep adjusting your anterior labial inclination, so you won't lose it with smoothening.

4- The hot plate won't do its work properly if it wasn't hot enough.

Fig ( 4-9 )

Fig ( 4-7 ) Fig (4-8)


29

5- avoid having too much wax on the labial surface of the base that is reaching the land area. You can

adjust that by looking at the upper border of the base from the fitting surface noticing the wax if over

added. You should be able to see a very thin layer of wax when reaching the land area of the master

cast.

EVALUATION CRITERIA

HELPFUL VIDEOS

https://www.youtube.com/watch?v=jbV0YG9U5wk

https://www.youtube.com/watch?v=AOzFOSe1bas

QUIZ

1. Which of the following

is temporary recording

base material:

A. heat cured acrylic resin

B. light cured acrylic resin

C. Gold

D. Base metal alloy

2. The occlusal plane

of rims should be

parallel to:

A. Camper line

B. Interpupillary line

C. Both of above

D. None of above

3. Ideal height of anterior maxillary

occlusion rim from reflection of cast

should be approximately:

A. 18 mm

B. 24 mm

C. 22 mm

D. 16 mm

Answers : 1. B / 2. C / 3. C

https://www.youtube.com/watch?v=jbV0YG9U5wk

https://www.youtube.com/watch?v=AOzFOSe1bas

5th exercise: Fabrication of Mandibular wax rim

Abeer Al-Hamdan

By

By: Abeer Al-Hamdan Reviewed by : Batool Alsa'aydeh

31 Figure 5.1 Figure 5.2 Figure 5.3

5TH EXERCISE: MANDIBULAR WAX RIM

Occlusion rim:- An occluding surface usually made of wax placed on a record base fabricated on the

master cast for the purpose of recording vertical and horizontal maxillomandibular relations and arranging

artificial teeth


Mandibular record base on master cast.

A sheet of light cured acrylic.

Acrylic bur.

Vaseline.

A sheet of Base plate wax.

Ruler.

Wax knife and lacron carver.

Hot plate or plaster spatula.

Bunsen burner and lighter.


I. Mark guidelines on the master cast

Draw a circle around the retromolar pad area on the master cast and divide it into 3 thirds (figure 5.1) and

extend the line drawn between the upper and middle third buccally (figure5.3) (at this level the height of

wax rim posteriorly will be)

also draw a line bisecting the ridge and extending it both labilaly (figure 5.2) and distally “posteriorly”


32

Figure 5.4

II. FABRICATION OF THE ACRYLIC BASE

a. At first add a separation media on the master cast (example: vasiline)

b. Put the acrylic sheet and extend it to the full depth of sulci by applying gentle pressure without

thining the acrylic sheet (you may use an eraser to do so because your fingers are tipped(

c. Put the master cast with the acrylic sheet on it in the light cure unit for 7-10 mins so

polymerization of MMA monomers take place. (revise the mechanism of polymerization of acrylic)

d. Using the acrylic bur smooth out the borders of the acrylic base and make some indentations along

the crest of the ridge (to maximize the retention of wax on it later on).

III. Add some sticky wax –if found- on the indentations made previously (also to maximize retention between the acrylic and the wax)

IV. Light up the bunson burner and start softening and rolling of baseplate wax sheet to form the wax rim (figure 5.4 A-D). Bend the wax rim to simulate the shape of the mandibular ridges.

V. Reheat both sticky wax and the wax rim formed gently then put the wax rim on the acrylic base above the sticky wax and push it gently trying to shape it while it’s still soft.

VI. WAX RIM SHOULD BE STRAIGHT AND NOT LABILAY OR LINGUALLY INCLINED (FIGURE 5.4 H)


33

VII. SEAL THE WAX RIM TO THE ACRYLIC BASE WITH A HEATED WAX KNIFE

VIII. ADJUST DIMENSIONS (HEIGHT AND WIDTH) ANTERIORLY AND POSTERIORLY

Heat up the hotplate and use it to melt down the wax to achieve the appropriate height

Then adjust the width using a heated wax knife or lacron carver by removing wax either labialy or

lingual depending on a line drawn to bisect the occlusal surface of the wax rim.

*Always remove the base from the cast when melting wax in order to keep the master cast clean and tidy.

IX. CLEAN UP YOUR WORK AND SMOTHEN YOUR WAX RIM BY GENTLY FLAMING IT.

NOTES AND ADVICES

1. Avoid over heating of any instrument because this will burn it and will darken your wax making it

unpleasing for sight.

2. Avoid thining of the acrylic base because this will make it weaker and more prone to fracture.

3. To get a good looking wax rim after flaming the wax use a cotton dipped in water and wipe it

along the wax rim.

EVALUATION CRITERIA

1. Wax rim is centered bucco-lingually

2. It’s 1-2 mm below the retromolar pad area posteriorly or at the line as

mentioned before.

3. Appropriate width and height anteriorly and posteriorly

4. Parallel to the residual ridge

5. Flat occlusal surface without deformities

6. Smooth with no voids

Table 5-1

Length Width

Anteriorly 18 mm 3-5 mm

Posteriorly parallel with the line drawn between upper and middle thirds of the retromolar pad area in step I

8-10 mm


34

HELPFUL VIDEOS

https://www.youtube.com/watch?v=Qlk3ufQ5Z5k

QUIZ

1. Give 3 differences between cold cured and heat cured acrylics?

You have to revise this from dental materials

Answer:

Cold cured is lower in strength and more prone to yellowing since it has more residual

monomer

better dimensional stability and less working time

Activator is tertiary amine in cold cured

2. Mention 2 main differences between upper and lower wax rims?

Answer:

a. measurements (height and width)

b. inclination of the rims (maxillary inclined labialy and buccally, mandibular

centered and straight on the residual ridge)

https://www.youtube.com/watch?v=Qlk3ufQ5Z5k

Majd olaimat

By

6th exercise: Jaw relation registration

By: Majd Olaimat reviewed by: Mos'ab Altawarah

36

FIRST EXCERSICE: JAW RELATION REGISTRATION

The aim of this lab is to obtain suitable relations between maxilla and mandible which include Vertical

and horizontal relations .

You should achieve the vertical jaw relationship >>

* Rest vertical dimension ( RVD ).

* Occlusal vertical dimension ( OVD ).

* Interocclusal distance: free-way space ( FWS )

Horizontal Jaw Relationship >>

* Centric jaw relation CR

Retruded Contact Position RCP

* Centric Occlusion CO

Inter Cuspal Position IC


Your maxillary and mandibular wax rim casts

Ruler and pencil

Wax knife and lacron carve

Bunsen burner and lighter

Hot plate

Your safety tools ( glasses, gloves, ...)

ADJUSTING THE OCCLUSAL PLANE (ANTERIORLY)

* Height: 1-2 mm below upper lip at rest (teeth show at rest)

* Orientation: parallel to interpupillary line. Look to the figure

below


37

ADJUSTING THE OCCLUSAL PLANE (POSTERIORLY)

* Height : at a level of the 2/3 the height of the

retro-molar pad.

* Orientation: parallel to the ala–tragus line

(Camper’s line)

DRAWING THE MID LINE

Mid line: vertical line passing through the middle of the face (upper & lower WR ). Also, this

line must to follow the middle notch on the occlusal table.

DRAWING CANINE LINES

at the corner of the mouth will be the tip of the canine. ( upper Wax Rim ) . use a dental floss to

connect the inner part of the eye and the outer part of the nose (nares), and continue until you

create a mark over the wax rim , this will be the place where the tip of the canine should be. Do

it similarly on the other side.

DRAWING THE SMILE LINE

This step is purely clinical, but you can draw it to a height of about 8 mm which is the average

distance from the neck of the central incisor to its' edge.

Here the three lines are drawn; midline and the 2 canine

lines


38

ADJUSTMENTS ON THE MANDIBULAR WAX RIM

Cut a small box-shape wax from the wax rim on the

posterior region of the mandibular rim, using your wax

knife, like in the picture aside.

ADJUSTMENTS OF THE MAXIILARY WAX RIM

heat your wax knife and Try to make V groove in the posterior part of your upper wax rim

(molar or second premolar place), it should contact with the boxes cut from the lower rim. In

the picture below 2 V shape groves are cut but 1 groove is enough.

Then rub in some Vaseline to the

"V' groove.

make a small roll of wax and put

it in the box shape in the lower

rim (without vasiline), while wax

roll is still soft bring both upper

and lower jaws together. The wax

will enter the "V" groove of the

upper jaw without sticking to it

because of Vaseline.

You have to make sure of jaw

vertical relation (RVD and OVD)

NOTES AND ADVICES

Pay attention to the cleanliness during your work.

"v" shape should not be too shallow or too deep .

It’s important to put vasiline only on the v shape groove of the upper rim.


39

EVALUATION CRITERIA

1- Vertical dimension

2- Horizontal dimension

3- Cleanliness

4- Can be relocated easily

5- *Midline

*Smile line

*Canine line

*Reference line

6- Boxes and V grooves design

HELPFUL VIDEOS

"v" shape:

https://www.youtube.com/watch?v=voqTlhy-zIE

I recommend this long video For the students who have NOT seen the experiment yet.

https://www.youtube.com/watch?v=OvcZWzERSbY

And you’re done. Nice work!

QUIZ

Questions:

Q 1: what do we mean by occlusal plane ?

Q 2: from where you should be starting the point for establishing the occlusal plane ?

Q 3: The lower occlusal rim is adjusted to meet evenly with the maxillary rim? (True or False).

https://www.youtube.com/watch?v=voqTlhy-zIE

https://www.youtube.com/watch?v=OvcZWzERSbY


40

Q 4: one of the following is used in Vertical dimension assessment:

A - Judgment of the overall facial support.

B - Visual observation of the space between the rims when the jaws are at rest.

C - Measurements between dots on the face when the occlusion rims are in contact and at rest .

D - phonetics.

E - All of the above.

Q 5: the orientation of the anterior occlusal plane is :

A- parallel to ala – tragus line.

B- parallel to the Camper’s line.

C- perpendicular to interpupillary line.

D- parallel to interpupillary line.

E- Non of the above.

Answers:

A 1: Occlusal plane: the average plane established by the incisal and occlusal surfaces of the

teeth. Generally, it is not a plane but represents the planar mean of the curvature of these

surfaces.

A 2: The starting point for establishing the occlusal plane is the maxillary occlusion rim.

A 3: True.

A 4: E .

A 5: D .

Tasneem Tayseer

By

7th exercise: Mounting master cast on articulator

By: Tasneem Tayseer Reviewed by : Batool Alsa’aydeh

42

SEVENTH EXCERSICE : MOUNTING THE MASTER CAST ON THE ARTICULATOR.

In this excersize we will Identify the ariculator and its classifications, learn the mandibular movements

and we will do the mounting of master casts on the articulator.


Wax knife and small pieces of wax to make a good seal between cast and the base plate.

Bowl and spatula for mixing of the gypsum.

Average value articulator.


I. IDENTIFYING THE ARICULATOR:

mechanical device that represents the temporomandibular joint and jaw members to which maxillary and

mandibular casts can be attached while in a proper vertical and horizontal relations to simulate

mandibular movements.

II. MANDIBULAR MOVEMNETS

We have three planes (frontal, sagittal and horizontal).

III. THE FRONTAL PLANE

1. Left lateral (ll) superior border. 2. Left lateral opening border 3. Right lateral superior border . 4. Right lateral opening border .


43

IV. HORIZONTAL PLANE

1. LL: left lateral border movement:

left condyle is the working while right condyle is non

working.

<when we move toward left , left condyle remains in centric

relation while right condyle moves anteriorly ,medially and

inferiorly >.

2. We have the bennet angle : The angle formed between

the sagittal plane and the average path of the balancing

condyle as viewed in the horizontal plane during lateral

mandibular movements.

3. We have bennet movement <side shift> : The bodily lateral movement in the rotation of the working

side condyle as the mandible makes a lateral movement.

V. SAGITTAL PLANE

we have 4 borders:

1. Posterior opening border

2. Anterior opening border 3.Superior contact border

4.Functional movement

* posterior opening border has two stages :

first is when the condyle is in the most superior position <pure

rotational movement)

second is when there is

anterior and inferior translation of the condyle.

* anterior opening border :

When closure occurs, tightening of the ligaments produces a posterior movement of the condyles < not a

pure rotational movement >.

* superior contact border :

mandible moves in superior direction until posterior teeth contact , further horizontal movement until the

maximum anterior position.

* functional movement :

free movements occurring within envelope of movement .

Most functional activities require maximum intercuspation, therefore typically begin at and below the

intercuspal position ,drops downward and slightly forward to the position of desired opening .

ADVANTAGES OF ARTICULATORS :

1. Important role in diagnosis, treatment planning and patient presentation.

2. Better visualize the patient’s occlusion .


44

3. Patient cooperation is not a factor once appropriate records are obtained .

4. Less chair time and patient appointment time is required.

CLASSIFICATION OF DENTAL ARTICULATORS

Hinge articulators

Average value articulators

Adjustable articulators :

- semi adjustable - fully adjustable

HINGE ARTICULATOR < CAST HOLDER >

The only movement is inaccurate opening and closing.

Shorter radius from the center of rotation to the lower incisors in the articulator so more curved of

closure.

Uses :

1. Case presentation for the patient.

2. Useless for diagnosis.

3. Restorations with significant errors.

4. Fabrications of temporary crowns.


45

AVERAGE VALUE ARTICULATOR

* Instrument that permits horizontal as well as vertical motion but does not orient the motion to the

temporomandibular joints. We call it the average value articulator because it has a fixed measurement

taken from the normal population.

* This articulator is according to Bonwill's triangle theory : the distance between the condyles

"intercondylar distance" equal to the distance between one condyle and the mid line , which make an

equilateral triangle with a 4 inches for each distance .

Uses :

1. Case presentation for the patient.

2. Single crowns.

3. Short span posterior bridge.

(max 3 units)

4. Removable partial denture

construction.

5. Complete denture construction.

6. Intra-oral adjustments well to be

necessary.

7. Useless for diagnosis.

Properties of this articulator :

1) it is non adjustable articulator.

2) designed using fixed dimension.

3) non arcon articulator .

< arcon articulator :mimics natural

patient ,condyle on the lower member

and glenoid fossa in the upper member >.


46

Why it is called a mean value articulator?

because it has 3 fixed mean values:

1) intercondylar distance (10-11) cm.

2) condylar guidance angle (33-34)degree.

< between condylar line orientated horizontally ‘ protrusion ’and horizontal line .

3) incisal angle (10-15)degree .

< the line following movement of mandibular incisors against the upper in protrusion movement >.

< we need shallow angles to preserve seal and facilitate the function >.

The posterior and anterior controlling factors are the same,

causing the mandible to move away from the reference

plane at a 45-degree angle. B, For premolar A to be

disoccluded from premolar B during a protrusive movement,

the cuspal inclines must be less than 45 degrees.

THE ADJUSTABLE ARTICULATOR

We have semi-adjustable and full-adjustable.

Most common adjustments :

1) The Radius of the hinge movement VIA face – bow transfer

2) The Horizontal condylar inclination.

3) The lateral condylar inclination.

4) The inter-condylar distance.

5) The incisal guidance.

PROCEDURE:

1) Put the incisal rod at the zero setting. (there are 3 lines on the rod, the upper line should be flushed

with the upper member surface)

2) Lock the condylar head movement so there is no lateral movement.

3) Put the upper mounting plate in the correct position then put the occlusal plate/table.

4) The incisal rod must touch the incisal table.

5) Put the maxillary cast with the wax rim on the occlusal table, “check that the midline is parallel to the

incisal pin”.


47

6) Put small amount of wax between model and occlusal plate to preserve the adjusted midline of the wax

rim in place.

7) Mix plaster of paris with water, in 1:3 water powder ratio.

8) Place the mixture on the top of the maxillary cast (fill the indeces) and some of the mixture on the

mounting plate. Sufficient quantity must be added so the excess plaster will go out on sides.

9) Remove the excess plaster and smoothen the surfaces with your wetted fingers.

10) Close the articulator, incisal rod must still touching the incisal plate.

11) Tie the upper member with the lower member of the articulator with a rubber band, as the plaster

will expand and distort the dimension if not tied.

12) When the plaster sets, remove any excess with plaster knife.

13) Remove the occlusal table and put lower mounting plate

14) Stick lower wax rim with the upper wax rim in the occlusal position.

15) Put the articulator upside down, put the plaster on the base of the mandible and a little on the

mounting plate.

16) Close the articulator and remove the excess plaster in same manner of upper cast mounting.

17) Plaster should be shiny and the articulator should be clean.

NOTES AND ADVICES

During work make sure that the incisal rod is at the zero setting all the time.

The incisal rod must touch the incisal table and don’t jump after plaster is set.

don’t wet the plaster too much with your fingers while cleaning.

EVALUATION CRITERIA

1) Incisal rod must touch the incisal plate.

2) Incisal rod must be at the zero setting.

3) Incisal pin within midline.

4) Cleanness of the articulator and casts.

HELPFUL VIDEOS

https://www.youtube.com/watch?v=OLOnOBiwbCU

QUIZ

Q1: Mention 3 types of articulator with one limitation for each one :

Q2: What are the fixed value in the average mean articulator ?

https://www.youtube.com/watch?v=OLOnOBiwbCU

http://www.google.jo/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwj-ysar0cLKAhUKWxQKHRjrAuUQjRwIBw&url=http://www.fotosearch.com/CSP473/k4732553/&bvm=bv.112454388,d.d24&psig=AFQjCNEiWpB20wNFt3Asi5CouU1tBTvFPA&ust=1453731192386154

Farah Albanna

By

8th exercise: Setting Of Maxillary Anteriors

By: Farah Albanna reviewed by: Mos'ab Altawarah

49

EXERCISE #8 SETTING OF MAXILLARY ANTERIORS

In this exercise you will set the acrylic teeth on the upper wax rim that you have made.


maxillary wax rim and master cast mounted on the articulator.

the occlusal plane, the incisal pin.

wax knife.

lacron carver.


I. BEFORE STARTING

-Put the occlusal plane on the articulator.

-Make sure that:

1-The incisal pin is on zero.

2-The mid line, the canine line and the smile line are marked on the wax rim.

*If the mid line does not coincide with the notch on the occlusal plane forget about the marked

one and mark a new one that exactly coincides with the notch.

*The canine line is marked according to the ala of the nose.

II. CENTRAL INCISOR

Labial view:

You need to make the incisal edge of the central incisor flush with the occlusal plane and the

mesial side should be on the mid line, by doing so you will eventually get the distal inclination

of the tooth.

Profile view:

The tooth should be slightly proclined “labially inclined”.

Occlusal view:

The tooth should be within the contour of the wax rim not beyond and not too much palatally.


50

III. LATERAL INCISOR

Labial view:

-The incisal edge should be 0.5-1 mm higher than the occlusal plane and parallel to the

occlusal plane, by doing this you will get the distal inclination.

-Notice that the lateral incisor is more distally inclined than the central incisor.

Profile view:

Similar to the central incisor but here we put the tooth in a more proclined position; the neck is

hidden by the wax more than the neck of the central since the lateral is more proclined.

Occlusal view:

Follow the incisal edge of the central incisor to get a nice smooth curve, for sure the tooth

must be within the contour of wax rim.

IV. CANINE

Labial view:

-The incisal edge should be touching the occlusal plane.

-The tooth has a slight distal inclination.

Profile view:

-The tooth should be placed in a vertical position with no labial inclination.

-The neck of the canine is more prominent than the central incisor.

Occlusal view:

When you look at the canine labially, only the mesiolabial surface of the canine will be visible

while the distolabial surface is hidden since the canine is rotated in a way to follow the curve

of the maxillary arch.


51

After setting the three anterior teeth on one side, start setting the other side and make sure

that you set the teeth in both side in a symmetrical way.

When you are done with upper anterior teeth setting, clean up the teeth and remove any

excess wax found on the teeth or on the cast. Soften the wax at the palatal surface and make it

smooth with the hard palate part of the base plate.

NOTES AND ADVICES

NEVER start your work without checking if the pin is on ZERO or not, and try to check it

every now and then.

Do your work step by step “remember that the shortest distance between two points is

the straight line connecting them ;)”

Be patient and aware since every step is important and needed for the next step to be

accomplished perfectly.

In order to clean up your work and make it more pleasing to sight, flame the wax gently

on the bunson burner and wipe it with wet gauze or cotton.

Don’t panic if something went wrong and try to fix it immediately in order not to waste

your time.


52

HELPFUL VIDEOS

https://www.youtube.com/watch?v=1m2tnTIk2pE

EVALUATION CRITERIA

https://www.youtube.com/watch?v=1m2tnTIk2pE

Duha Zahran

By

9th exercise:

Setting of maxillary

posterior teeth

By: Duha Zahran reviewed by : Batool Alsa'aydeh

54

9TH EXERCISE: SETTING OF MAXILLARY POSTERIOR TEETH

In this exercise you are going to replace the upper posterior wax rim by upper posterior acrylic teeth.


Your upper wax rim placed on master cast and mounted on the articulator

Occlusal plane

Wax knife

Lacron carver


I. BEFORE YOU START

-Make sure to correct any mistake in the setting of your upper anteriors as it is going to affect the setting

of the posteriors.

-Make sure that the insical pin is always touching the incisal table, and keep on checking it after each

step.

II. SETTING OF MAXILLARY FIRST PREMOLAR

-leave a 1-2mm space between the canine and the 1st premolar (You must have a broken contact with the

adjacent canine).

-Long axis is perpendicular to the occlusal plane.

-It's palatal cusp is about 0.5 mm above the occlusal plane.

-only It's buccal cusp is in contact with the occlusal plane. Figure (9-1) & (9-2)

Broken contact

Figure (9-2) Figure (9-1) Figure (9-3)


55

III. SETTING OF MAXILLAY SECOND PREMOLAR

-the Long axis is perpendicular to the occlusal plane when viewed from the front or the side.

-Both buccal and palatal cusps are in contact with the occlusal plane. Figure (9-4)

IV. SETTING OF MAXILLARY FIRST MOLAR

-Long axis slopes buccally when viewed from the front, and slopes distally when viewed from the side.

-The only cusp in contact with the occlusal plane is the mesiopalatal cusp. Figure (9-5)

-distobuccal cusp is the farthest cusp from the occlusal plane. Figure (9-6)

- this inclination is made to compensate for curve of Spee.

V. SETTING OF MAXILLARY SECOND MOLAR

-Long axis slopes buccally more steeply than the first molar when viewed from the front and slopes

distally more steeply than the first molar when viewed from the side. Figure (9-6)

-None of the cusps are in contact with occlusal plane but the mesiopalatal cusp is the nearest to it.

Figure (9-7)

Palatal view buccal view

Mesiopalatal cusp of the first maxillary

molar touches the occlusal plane

Figure (9-4)

Figure (9-5)

Figure (9-6)


56

VI. CHECKING THE A-LINE AND THE B-LINE

-use a ruler or any straight instrument to check the buccal

alignment of the posterior teeth. The canine, premolars and

the mesiobuccal cusp of the first molar should be on the

same line that is called the *A-line*

-another line lies on the buccal side of molars. The four

buccal cusps of the first and the second molars should be on

the same line that is called the *B-line* . figure (9-8)

NOTES AND ADVICES

1- Check your incisal pin after each tooth you set form, and correct any jump in the pin by tilting

the tooth in the proper way to achieve the right vertical dimension

2- Never proceed with your work if the pin is not touching the incisal plate.

3- Clean up your work and smoothen the wax.

EVALUATION CRITERIA

- 1st PM

Buccal view: perpendicular on occlusal table

Occlusive: Buccal touching table

Broken contact with the canine

Mesiopalatal cusp is

the nearest to the

occlusal plane but it is

not touching.

A

B

Figure (9-7)

Figure (9-8)


57

- 2nd PM

Buccal view: perpendicular on occlusal table

Occlusive: both cusps are touching the occlusal table

- 1st Molar

Buccal view:MP cusp touching

Orientation of occlusal surface

- 2nd Molar

Buccal view: MP cusp nearest to occlusal table

Orientation of occlusal surface

- Cleanliness

- Symmetry

- A line

- B line

- Vertical dimension preserved (insisal pin reading)

HELPFUL VIDEOS

https://www.youtube.com/watch?v=iXbcf2QtX3o

QUESTION

Why is it important to have a broken contact between upper 3 and 4?

In order to achieve a class I occlusion with the lower teeth since the lower residual ridge is longest and

widest than the upper residual ridge.


Aya Al-ayyat

By

10th exercise: Setting of mandibular anterior teeth

By: Aya Alayyat Reviewed by: Batool Alsa’aydeh

59

EXCERSICE #10: SETTING OF MANDIBULAR ANTERIOR TEETH

In this exercise, you will set the lower anterior acrylic teeth on the lower wax rim.


Your articulator with the mounted wax rims.

Lower anterior set of teeth.

Wax knife.

Acrylic bur.

A lighter.

Lacron carver.


I. MARKING THE MIDLINE.

Mark the midline following the midline of the upper wax rim.

II. SETTING OF MANDIBULAR CENTRAL INCISORS

-lower anterior teeth should be set 1mm above the occlusal surface

of the wax rim.

- The mesial surface should be exactly on the midline.

- Central incisors must be perpendicular to the occlusal surface or slightly proclined labially (5 degrees

not more than that).

- The neck of the tooth should be positioned vertically or slightly tilted distally

- Overjet: the horizontal overlap, and must be 2 mm.

- Overbite: the vertical overlap, and must be 1mm.


60

Incisal guidance angel is formed by the amount of vertical overlap or overbite and the horizontal

overlap or overjet between the teeth when viewed from the sagittal plane. In average value

articulator, it is 15 degrees.

III. SETTING OF MANDIBULAR LATERAL INCISORS

- Follow the curvature of maxillary anterior teeth,

and at the same level of mandibular central incisors

maintaining 1 mm overbite and 2 mm overjet.

- Must be more tilted distally than central incisors

and set vertically.

IV. SETTING OF MANDIBULAR CANINE “CUSPIDS”

Set the canine to follow the curvature of the maxillary anterior teeth and the height of the mandibular incisors

maintaining 1 mm overbite and 2 mm overjet, also the cusp tip might be slightly higher than incisal edges.

- set Cuspids more distally tilted than laterals and inclined slightly lingually.

***If the pin jumped after setting of lower teeth then a steep incisal guidance angle is present

and you have to 1- increase the overjet or 2- decrease the overbite to make it shallower.

***If there’s a premature contact between the upper and lower anterior teeth and no edge to

edge contact on maximum protrusion then a shallow incisal guidance angle is present you have

to 1- increase the overbite or 2- decrease the overjet to increase it.

V. AT LAST, REMOVE THE EXCESS OF WAX THAT COVER THE NECK OF THE TEETH AND CLEAN YOUR MASTER CAST.

Canine lateral incisor central incisor

IMPORTANT STEP: Loosen the screws on the backside of the articulator and do lateral and

protrusive movements and check the incisal pin for any jump that could happen between each

tooth setting and the next one


61

NOTES AND ADVICES

You have to check that your maxillary anterior teeth is perfect and your incisal pin is

touching the incisal table exactly on the zero reading before you start setting and keep

checking that after each tooth.

EVALUATION CRITERIA

Centrals

- Midline on with maxillary

centrals

- Long axis perpendicular to

plane

- Horizontal overlap (overjet)=

1.5 mm

- Vertical overlap (overbite)= 0.5

- 5º Labial inclination

- No protrusive or lateral

interferences

- Edge to edge touch with

maxillary centrals in protrusive

Laterals

- Slight distal inclination of long

axis

- Incisal edge in smooth

symmetrical curves with centrals


interferences

- Horizontal overlap (overjet)= 1.5

mm


Cuspids

- Distal inclination of long axis

greater than laterals

- Lingual inclination 5º

- Incisal edge in smooth

symmetrical curve with laterals

and centrals

- Incisal edge on plane


interference

- Horizontal overlap (overjet)= 1.5

mm


HELPFUL VIDEOS

https://www.youtube.com/watch?v=jM-s7oYQRos

https://www.youtube.com/watch?v=4q6V-N22wsM

QUIZ

Q1 How do you calculate the correct occlusal vertical dimension (OVD) for the patient during

jaw registration?!

Q2 upon protrusion in try in stage there was an open bite anteriorly, give 1 reason and how

could we fix it?

Answers:

Q1: RVD-OVD= FWS

Q2: premature contact of anterior teeth, correct raise the upper anteriors a little bit.

https://www.youtube.com/watch?v=jM-s7oYQRos

https://www.youtube.com/watch?v=4q6V-N22wsM

11th exercise: Setting of mandibular

posterior teeth

Mira Salem

By

By: Mira Salem Reviewed by: Duha Zahran

63

11TH EXERCISE: SETTING OF MANDIBULAR POSTERIOR TEETH

In this lab setting of posterior mandibular teeth is to be done, students should have their mandibular

anterior teeth perfectly set in relation to the upper teeth and incisal pin should always be at zero level.


Your mounted wax rims on Articulator.

Lower anterior set of teeth.

Wax knife.

Acrylic bur.

Lacron carver.


I. MANDIBULAR 1ST MOLAR (IT IS THE KEY STONE)

TIP: take a small amount of sticky wax and stick the lower 1st molar with the upper 1st molar in the

right position (MP cusp of the upper occlude with the center fossa of the lower) then soften the wax on

the lower wax rim and seal it.

Buccal view:

As you can see the mesiobuccul cusp tip

of maxillary 1st molar should engage MB

groove of mandibular 1stmolar. The

adjacent marginal ridges of maxillary 1st

molar and 2nd premolar must be at the

same level for the lower 1st molar to

properly engage them.

Lingual view:

Check the relationship and make

sure that the maxillary palatal cusp

tips of 1st molar engage the central

fossa of mandibular 1st molar.


64

II. SETTING OF MANDIBULAR 2ND MOLAR

You have to make sure that the central

fossa of the 1st molar is properly

aligned over the ridge using clear

plastic ruler and the markers on the

cast. If the central fossa is shifted either

buccal or lingual to the ridge make

appropriate adjustment.

Never ever forget to check:

Balanced contact

1- In protrusion there is contact posteriorly.

2- In lateral movement at the non-working side.

And the incisal pin should not jump during these movements if so do some adjustments and

tilting of the tooth before moving to the next tooth.

Now move to mandibular 2nd molar.

Position the mandibular 2nd molar in centric

occlusion.

Inappropriate positioning and angulations of

mandibular 2nd molar can cause destabilization

and/ or dislodgement of the denture.

Check lingual centric occlusion. Make sure that

the palatal cusps of maxillary 2nd molar occlude

properly with the central fossa of mandibular 2nd

molar.

IMPORTANT STEP: never ever forget to check balanced

occlusion by checking balanced contact on both protrusive and

lateral movements and don’t forget to check centric relation

before you move to the next tooth.


65

III. MANDIBULAR 2ND PREMOLAR

Mandibular 2nd premolar is set before 1st

premolar.

The buccal cusp tip should engage the space

between the maxillary 1st premolar and

2ndpremolar.

The adjacent marginal ridges of maxillary

premolars must be at the same level of the

lower 2nd premolar in order to properly engage

them.

IV. MANDINULAR 1ST PREMOLAR

The mandibular 1st premolar is now set to

complete the mandibular posterior teeth.

The buccal cusp should engage the mesial

marginal ridge of maxillary 1st premolar.

Check lingual centric occlusion. Make sure that

the palatal cusp of maxillary 1st premolar

occludes properly with the distal marginal ridge

of mandibular 1st premolar and the mesial

marginal ridge of the mandibular 2nd premolar.

The buccal cusp contacts the mesial

triangular fossa of the upper 2nd premolar

and marginal ridges between the two upper

premolars


66

NOTES AND ADVICES

- Check the incisal rod if touching the incisal table every now and then and on all movements (protrusion

& lateral movements).

-Mandibular premolars follow the curvature of the canine.

From a labial view this makes the canine the most prominent tooth.

EVALUATION CRITERIA

Centric Occlusion

Right Side

- Buccal View: _____________________

- Lingual View: _____________________

Left Side

- Buccal View: _____________________

- Lingual View: _____________________

Observe the incisal pin contact to

ensure a maintained OVD at all stages

of teeth arrangement

Working Occlusion

- Right Side: __________________

- Left Side: ____________________

Balancing Occlusion

- Right Side: __________________

- Left Side: ____________________

Protrusive Occlusion

Edge to Edge: _______________

Posterior balancing contacts: _______________

HELPFUL VIDEOS

From JUST university


QUIZ

Q1: mention the factors affecting

balanced occlusion (according to

Hanau):

1- ------------------------------------------------- .

2- -------------------------------------------------- .

3- -------------------------------------------------- .

4- -------------------------------------------------- .

5- -------------------------------------------------- .

Q2: Why do we call curve of spee the

compensating curve?


12th exercise: Wax Contouring and Festooning

Leen Mahasneh

By

By: Leen Mahasneh Reviewed by : Batool Alsa'aydeh

68

12TH EXERCISE: WAX CONTOURING

The aim of this exercise is to contour the wax around the teeth to mimic the shape, the contours and the

texture of the gingiva.


Wax.

Lacron carver.

Bunsen burner.

Bowl; not necessarily to use it but you can fill it with water and dip the denture in it to cool the

wax down.

Gauze; to clean the teeth after you finish your work.


I. ADDING WAX

- You should add more wax to the wax that’s already present; because we need sufficient amount

of wax to carve in.

- Roll a piece of wax, heat it and drip it around all the teeth or soften a long piece of wax and put

it above all teeth.

- If you already have bulk of wax, you may not do this step.

II. EXPOSING THE FACIAL SURFACES OF THE TEETH (THE CLINICAL CROWN)

￮ carve around each tooth while holding the lacron

carver in 45o angle with the long axis of the tooth.

The upper central incisor and the upper canine have

the same gingival height while the upper lateral

incisor has it at a lower level.

III. CARVING THE MARGINAL GINGIVA

- Carve the wax around the teeth until you get a 2mm thick wax.


69

IV. CARVING THE REST OF THE POLISHED SURFACE

- You should carve the wax from above the gingival margin

to the flange.

- Buccally:

o In the upper denture: it should be convex.

o In the lower denture: it should be convex or flat.

- Lingually/palately:

o In the upper denture: we want a smooth

transition from the gingival margin to the palate.

o In the lower denture: It should be concave.

- When you finish, reclean the denture from the small

pieces of wax that fell while you’re carving.

V. CARVING THE ROOT EMINENCES

- Carve triangular depressions between the teeth, so that you get prominent areas in the wax above

teeth that mimic the appearance of the roots.

o The carving should be above the level of the papilla (don’t reach them).

- These depressions should mimic the length of the roots, the shape and the angulation, ex: the

roots of the centrals are straight, of the laterals are a little bit shorter and distally inclined and

canines’ roots are the most prominent (you should know the anatomy of the teeth).

- Carve the depressions around the incisors to be very faint because the root eminences of the

incisors are not really prominent, but from the canine and posteriorly the roots are more

prominent so you carve deeper depressions.

VI. MAKE THE SURFACES SMOOTH

- Pass the surfaces on the flame quickly to get smooth surfaces and no sharp angles, but be careful

not to melt the wax or else all of your work will go to waste.

NOTES AND ADVICES

- Your work should mimic the natural look of the gingiva, do not make the depressions too deep

because gingiva will appear as it is inflamed.

- Don’t carve in the wax while it’s hot, cool it down after every step that you heat the wax in or

else the teeth will move from their place and you’ll change all the dimensions.

- One of the tricks to clean the teeth is by passing the occlusal surfaces of the teeth on the flame

then wiping them with gauze or brushing them with a clean tooth brush.

- You can use wet wipes to clean all the surfaces and give them a shiny appearance.

- Check that the pin is still touching the incisal table.


70

EVALUATION CRITERIA

- Sufficient Wax amount covering all teeth necks.

- clinical crowns are visible.

- The whole work is done to give a natural appearance to the denture.

- Make sure that there’s similarity on both sides.

- Work is clean, tidy and pleasing with no wax remnants on the palate area or the casts.

HELPFUL VIDEOS

https://www.youtube.com/watch?v=1ddYe545BIg

The video doesn’t go with the same steps, but it’s good to watch, it’ll give you a good idea of what you’ll

do in the lab.

https://www.youtube.com/watch?v=1ddYe545BIg

Exercise 13: final laboratory steps in CD construction

Zainab Al-Zoubi

By

By: Zainab Alzoubi

72

13TH EXCERSICE : FINAL LABORATORY STEPS IN CD CONSTRUCTION

This lab is a e theory lecture.

We will talk about the final laboratory steps in making the complete denture. Keep in mind that we will not

do the whole these steps in fourth year clinics.

NOTE: the slides of this lab are almost empty, so i read the last 3 sheets, and tried to coordinate the

information that written in both of them and FINALLY I end up with this SUMMARY for the LABORATORY

steps without go much in theoretical details or explaining why to do each step.

If you want to go in the details you can read sheet 11,12 and 13.


Flasks, investment materials ( splaster of paris, stone), vasline, brush,

articulating paper, and burs.

The compression moulding machine, polishing machine, and Straight

hand piece.


I. STEP 1 : FLASKING

Flasking; is the process of in, in preparatory to molding the final denture base material ( PMMA )

into the desired form.

Steps:

1. Separate the cast from the mount, and this achieved simply by hitting at the junction between the cast

and the mount.

2. Put it inside the flask, then you have to check these criteria and insure that everything is ok;

a- there should be a space all around the cast.

b- there should be around 3-6 millimeters above the occlusal and incisal surfaces of the teeth.

If there is no space, you can trim of the base of the cast until you get this space.

By: Zainab Alzoubi

73

c- there is no undercut behind the retro-molar pad area because this will complicate the retreating of the

denture and the cast in the following procedures.

3. apply a separating media, like vasline, to coat:

- inner surface of the flask .

-surfaces of the cast and denture.

so the investment material which is plaster of Paris or dental stone will not stick to the denture later

on.

4. Make a mould around the denture inside the flask itself, as the following;

and DON'T forget to add layer of vasline between each two consequence layers.

Number of the pour Investment material Criteria

The 1st pour plaster of Paris it should flush at the

level of the lower half of

the flask and the land area

of your master cast The 2nd pour plaster and stone in equal

ratios (1:1) covers all surfaces of the

denture and teeth Except the occlusal and

incisal tips the 3rd pour pure stone. Covers the occlusal and

incisal tips. 5. Close the lid of the flask and wait until the mould sets completely.

II. STEP 2 : WAX ELIMINATION (THE BOIL-OUT)

in this step, and as the name indicates, we will eliminate (soften) the wax to replace it with PMMA later on.

Steps:

1. Place the flask in BOILING WATER for 4-6 minutes.

2. Take it out from the water bath.

3. Open the flask.

4. Now, you will have to parts;

- the first one; is the cast with the wax and temporary base and the 1st pour in the lower half of the flask.

the second part; is the teeth held in their places with the 2nd and 3rd pour in the upper half of the flask.

By: Zainab Alzoubi

74

5. Clean the two parts properly from all the soften wax which you can find around the teeth and on the

casts using with the proper instruments (you can use a brush, so all debris are removed away)

6. then dry them.

A further step; If you use acrylic teeth, there will be chemical bond

between the teeth and the denture base, if not (porcelain for example) it

will be only mechanical bond.

7. in order to enhance the mechanical retention between the teeth and the denture base, you have to

make some grooves or notches on the inner surfaces of the teeth.

III. STEP 3: MIXING AND PACKING OF HEAT CURE PMMA

In this step we will introduce PMMA in the space that is left by elimination of wax.

Steps:

1. Mix the powder of PMMA and liquid in suitable ratio; (3:1 by volume) OR (2.5:1 by weight) and wait until it

become in the DOUGHY stage.

2. During waiting, apply TWO LAYERS of a separating medium (vasline) all over the cast and on the pours

except around the teeth.

because we don't want the acrylic material to stick on nothing rather than teeth.

3. Now, we want to mold PMMA in a confined shape, so choose the packing technique you prefer.

Suppose that we choose compression moulding technique , so we will go in these steps:

a. apply pressure on the two casts by using special equipment.

b. the excess PMMA will go out the space that it should accommodate the material (PMMA).

c. Keep repeating the above two steps with different quantity of pressure each time, until there is no

excess material goes out , usually you need 3-4 cycles of repeating.

IV. STEP 4 : CURING (POLYMERIZATION)

Which is the technical name for the heating process used to control the initial propagation and

polymerization in the denture mould.

*There are two types of packing techniques:

-compression moulding technique (which is a method that

depends on applying pressure on the casts)

-Injection moulding technique.

Most of laboratory rely on Compression Moulding

Technique rather than injection Moulding Technique

which needs special equipment and it is very expensive.

By: Zainab Alzoubi

75

There are different types of curing cycles [ for heat cured PMMA]:

1. Long curing cycle (the most recommended):

a. Heating under controlled constant temperature of (74 ºc) for about 8 hours.

then

b. Terminal boil at (100 ºc) for 2-3 hours.

2. Short curing cycle:

a. Heating the flask at (74 ºc) for about 2 hours.

Then

b. Terminal boil at (100 ºc) for 1 hour.

After curing; let the flask to cool down slowly at room temperature for 30 minutes

“bench cooling” to minimize the stress produced in denture base.

V. STEP 5: DEFLASKING ( TAKE OUT "THE DENTURE WITH THE CAST" FROM THE FLASK)

In this step we have to retrieve the denture & the cast from the pour, and this means we have to be careful

upon deflasking because we will do some occlusal adjustments (laboratory remount) and selective grinding on

the cast in the next step.

STEPS of deflasking:

1. Remove the cover of the flask.

*there are special deflasking compartments you can use.

* there are some holes at the side of the flask, and by using special instruments we can open the flask.

2. Now the flask is opened, we can use the hammer carefully to push the investment material out.

3. Catch the cast in one hand, use the other one to remove the anterior parts of the cast (anterior to the

teeth) by using a special instrument.

4. You can then easily remove the third pour layer that covers the occlusal and incisal edges of teeth.

5. The result is having the denture (which is made up from PMMA and teeth) and the cast attached to it

with its prominent indexes.

And by this we have done with deflasking completely.

74 ºc , for 8 hours

100 ºc, for 1 hour 74 ºc, for 2 hours

100 ºc, for 2-3 hours

By: Zainab Alzoubi

76

VI. STEP 6: LABORATORY REMOUNT AND SELECTIVE GRINDING

Selective grinding: modification of the occlusal forms of the teeth by grinding at selected places to achieve

good centric occlusion and free excursive movements to improve function and correct any errors that could

happen during all the above steps.

**Selective grinding should be conducted at the lab bench and before retrieval of the dentures from the

master cast.

*Instruments:

articulating paper, small burs on straight hand piece

*Steps of selective grinding and occlusal adjustment must be done in a sequence:

1. Restore the vertical dimension.

2. Refine centric occlusion.

3. Perfect working and balancing occlusion (lateral movement).

4. Correct protrusive occlusion.

*Rules for selective grinding: (four rules)

These rules should be done by sequence from rule #1 to rule #4

First rule :

Evaluate the case in centric occlusion.

Observe the incisal pin (vertical dimension); If you find it open, then use articulating paper (40-65

micrometer) to find the premature contacts in centric occlusion.

STEPS:

1. bring an articulating paper. Notice that the two sides of it are with deferent colors ( blue and red).

2. To test the CENTRIC RELATION, choose one color for the for the maxillary and the other for

mandibular centric occlusion.

Let us assume, for example, that we choose the red surface of the articulating paper for making

centric occlusion of maxillary teeth and blue surface for centric occlusion of mandibular teeth.

3. close the articulator at centric.

4. open the articulator

5. flip the paper upside down

6. close the articulator again, Loosen condylar locks, do lateral and protrusive movements (here

the red surface will be for eccentric movement for mandibular teeth and the blue surface for

eccentric movement for maxillary teeth.

By: Zainab Alzoubi

77

The results that you may have are summarized in the following table.

Centric Relation (normal case)

Erores could be because of either:

I :Premature lower buccal cusps II :Premature upper lingual cusps

To decide either to trim the cusps or deepening the opposing fossae, we have to determine the type of the case, by using the articulating paper.

Errors Cases

CASE 1 : If the cusps has one color "red and blue colors are superimposed with each other in all places on the teeth", then it's high at centric relation ONLY. Conclusion There is one premature functional cusp (either upper palatal or lower buccal). Solution We have to deepen the opposing fossa.

Solution:

I :Deepening the maxillary fossa opposing the premature lower buccal cusp

II :Deepening the mandibular fossa opposing the premature upper palatal cusp

By: Zainab Alzoubi

78

CASE 2: If the cusps have two colors" the red dots and the blue dots are separated from each other", then it is high in centric and eccentric relation, both of them. *eccentric mean; (working, balancing or protrusive possessions). Solution: reduce the cusp rather than deepening the opposing fossa. Then, either;

I :Reduce the lower buccal cusp II :Reduce the upper palatal cusp

And by this we finished with the first rule correctly, so we end up with a (correct centric relation) and

touching incisal pin in its place (correct vertical dimension).

7. Than we move on and adjust the working and balancing sides.

adjust the working relation. (i.e.; the working side relations)

We have to have the following;

- At the working side: the contact should be between both upper buccal cusps with lower buccal cusps

and palatal with lingual cusps.

- At the balancing side: the contact should be between upper palatal and lower buccal cusps (the

functional cusps).

Working relation ( Normal case)

Errors Cases

1.Case 1: There is a proper contact on the working side but there is NO contact on the balancing side. (interference exists on working side) Conclusion: we have premature contacts on working side that need elimination to achieve balancing occlusion.

By: Zainab Alzoubi

79

Solution: Second rule; (PULL rule); (Palatal Upper, Lingual Lower). These cusps we have to grind ( we decide each couple of them depending on the case)

Here; Reduce the Buccal Upper

Here; Reduce the Lingual Lower

2. Case 2: there is contact on the balancing side but there is no contact on the working side. (the interference exists on the balancing side). Solution: Third rule; reduce the lingual slope of the mandibular buccal cusp. As the following;"as the lines on the buccal cusp indicate".

8. Adjust the protrusive movement:

Normal case: the anterior teeth to be in edge-edge relation and to have contact between posterior teeth in order to get stable denture. ANY error in the protrusive movement solved by the Forth rule.

Errors Cases:

By: Zainab Alzoubi

80

1. First case: there is posterior contact with NO edge-to-edge contact. Solution: Reduce the distal incline of the upper buccal cusps and the mesial inclines of the lower lingual cusps.

2. Second case: there is edge-to-edge contact with no posterior balancing contact

Solution: Reduce from the palatal surface of the upper anterior teeth (increase the over jet) or/and reduce from the incisal edge of the lower anteriors (decrease the over bite).

BY this we have done with the laboratory adjustments and selective grinding :D

By: Zainab Alzoubi

81

VII. STEP 7: CARBORUNDUM PASTE MILLING

is the procedure of refining or perfecting the occlusion of complete dentures or RPD by placing

abrasive material (here it is carborundum past) between their occluding surfaces while the dentures

make contact in the various excursions on the articulator.

STEPS:

1. apply a layer of the paste on the occlusal surfaces and incisal edges.

2. Move the articulator into right lateral, left lateral and protrusive movements.

3. Move the articulator in a circular movement.

4. When milling is completed remove all traces of carborundum.

Make sure that you are using light strokes do not force or press.

VIII. STEP 8: TAKING AN IMPRINT OF THE OCCLUSAL SURFACES

Is a step that facilitates the clinical remount later on.

In order to preserve, at least, occlusal relationship between occlusal plane of maxillary arch to the hinge

axis (what we had done by face bow).

Do the following;

1. place the occlusal table on the articulator instead of lower denture.

2. Mix some plaster and pour it on the occlusal table.

3. Close the articulator on the mix.

By doing this step, you will achieve the inclination of maxillary teeth in relation to hinge axis to facilitate the remounting later on.

IX. STEP 9: FINISHING AND POLISHING

1. Separate the cast from the acrylic denture carefully, preserving and sacrificing the casts.

2. remove the excess acrylic using tungsten carbide burs (we use different shapes and sizes according to

the area we are going to finish).

3. If there are any acrylic remnants in between the teeth [as a result of un-removed wax] we have to remove

it using a very small bur.

4. We do the polishing on the polishing machine using polishing paste or special cloth, the palatal area

in particular is difficult to polish.

The well-polished surfaces appear glossy, we polish the occlusal surface as well as the polished surfaces BUT

we don't polish the fitting surface.

5. By using a very small bur we can do some stippling on the area of anterior gingiva trying to mimic the

natural gum but with no exaggeration and without making deep grooves. (additional step).

NOW, the dentures are FINALLY READY to be delivered inside the patient's mouth. :'D

By: Zainab Alzoubi

82

HELPFUL VIDEOS

I have searched for videos, and fortunately I found the videos that the doctor

showed them in this lab :

Flasking

https://www.youtube.com/watch?v=LRGMAWzph0o&list=PLFF885B82601839F6&index=1

Wax elimination - Boil Out

https://www.youtube.com/watch?v=D6KxeY3i1V8&list=PLFF885B82601839F6&i

ndex=1

Packing and Curing the Flask

https://www.youtube.com/watch?v=YnqqKPvR-

OU&list=PLFF885B82601839F6&index=12

Deflasking

https://www.youtube.com/watch?v=rd4SaksfTdg&list=PLFF885B82601839F6&in

dex=13

Remount Procedures: Clinical and Laboratory Procedures

https://www.youtube.com/watch?v=nens2LjNO9g&index=16&list=PLFF885B826

01839F6

Remounting the Processed Complete Denture

https://www.youtube.com/watch?v=3MUHkw821HA&index=19&list=PLFF885B8

2601839F6

Equilibration in Working and Balancing

https://www.youtube.com/watch?v=tmDFw4gQfBk&index=20&list=PLFF885B82

601839F6

Correction of the Occlusion After Processing

https://www.youtube.com/watch?v=2LW3rITMko8&index=15&list=PLFF885B826

01839F6

Finishing and Polishing the Complete Denture

https://www.youtube.com/watch?v=-

9naKnfJd6U&list=PLFF885B82601839F6&index=14

https://www.youtube.com/watch?v=LRGMAWzph0o&list=PLFF885B82601839F6&index=1

https://www.youtube.com/watch?v=D6KxeY3i1V8&list=PLFF885B82601839F6&index=1

https://www.youtube.com/watch?v=D6KxeY3i1V8&list=PLFF885B82601839F6&index=1

https://www.youtube.com/watch?v=YnqqKPvR-OU&list=PLFF885B82601839F6&index=12

https://www.youtube.com/watch?v=YnqqKPvR-OU&list=PLFF885B82601839F6&index=12

https://www.youtube.com/watch?v=rd4SaksfTdg&list=PLFF885B82601839F6&index=13

https://www.youtube.com/watch?v=rd4SaksfTdg&list=PLFF885B82601839F6&index=13

https://www.youtube.com/watch?v=nens2LjNO9g&index=16&list=PLFF885B82601839F6

https://www.youtube.com/watch?v=nens2LjNO9g&index=16&list=PLFF885B82601839F6

https://www.youtube.com/watch?v=3MUHkw821HA&index=19&list=PLFF885B82601839F6

https://www.youtube.com/watch?v=3MUHkw821HA&index=19&list=PLFF885B82601839F6

https://www.youtube.com/watch?v=tmDFw4gQfBk&index=20&list=PLFF885B82601839F6

https://www.youtube.com/watch?v=tmDFw4gQfBk&index=20&list=PLFF885B82601839F6

https://www.youtube.com/watch?v=2LW3rITMko8&index=15&list=PLFF885B82601839F6

https://www.youtube.com/watch?v=2LW3rITMko8&index=15&list=PLFF885B82601839F6

https://www.youtube.com/watch?v=-9naKnfJd6U&list=PLFF885B82601839F6&index=14

https://www.youtube.com/watch?v=-9naKnfJd6U&list=PLFF885B82601839F6&index=14

By: Zainab Alzoubi

83

QUIZ

Q1) How much time could the wax elimination process take in boiling water?

Q2) Mention the components and the criteria for each pour when preparing the

mould.

Q3) Mention the types of heat curing process, and what is the recommended

temperature needed by each one.

Q3) Suppose that you are doing occlusal grinding, and while making a lateral

movement to the right side (you move the upper jaw into the right side), you

find that the cusps of upper and lower jaw in the left side are not touching

each other.

what should you do now?

Q4) Upon doing a protrusive movement, you find that there is edge-to-edge

contact with no posterior balancing contact, this could happen because:

a. high over jet.

b. short overbite.

c. long overbite.

d.non of the above.

e. two of the above.

Q5) What is the name of the material that used for the milling process?

Answer of Q4) c.

organization - university of jordan dentistry ......organization it was made by a group of students...

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