Complete Denture Terminologies & Introduction

Complete Denture

Terminologies & Introduction

Zainab Talib Kareem

With Best Wishes

زينب طالب كريم /ماجستير صناعة الاسنان

يات الاسناننقسم تق

الطقم الكاملمادة

Dentulous

A condition in which complete set of natural teeth are present in the mouth.

Fig: (1) dentulous

Edentulous . A condition in which the mouth is without teeth.

Fig: (2) Edentulous.

Partially edentulous

A condition in which some of the natural teeth are lost.

Fig: (3) Partial edentulous.

Denture

An artificial substitute for missing natural teeth and adjacent tissues.

Complete Denture

A removable dental prosthesis that replaces the entire dentition and associated

structures of the maxillae or mandible.

Fig:(4) Complete denture.

Partial denture

A dental prosthesis that restores one or more but not all of the natural teeth and/ or

associated parts and that is supported in part by natural teeth, dental implant sup-

ported crowns, abutments, or other fixed partial dentures and or the mucosa. It may

be fixed or removable.

Removable partial denture

A partial denture that can be removed and replaced from the mouth.

Fig:(5) Removable partial denture

Fixed partial denture A partial denture that is

cemented to natural teeth

or tooth roots and/or dental

implants.

Fig:(5) Fixed partial denture

Immediate denture

A complete denture or removable partial denture fabricated for replacement

immediately following the removal of natural teeth.

Single complete denture

A single denture is a complete denture that occludes against some or all of the natural

teeth, a fixed restoration, a previously constructed removable partial denture or

complete denture.

Over Denture

A removable partial or complete denture that covers and rests on one or more

remaining natural teeth, roots, and/ or dental implants.

Fig:(6) Over denture

Implant prosthesis

Any prosthesis (fixed or removable or maxillofacial) that utilizes dental implants in

part or whole for retention, support, and stability

Fig:(6) Implant prosthesis

Obturator

A prosthesis used to close a congenital or acquired tissue opening, primarily of the

hard palate and/or contiguous alveolar structures.

Steps of construction of complete denture:

Clinical steps

Laboratory steps

1. Examination of the patient

2. Primary impression a- Pouring the impression and preparation of the

study cast (from plaster),

b- Construction of custom tray.

3. Final impression (custom tray) Pouring master cast (from stone plaster).

Construction of record blocks.

4. Recording jaw relations Selection color of

teeth

Mounting the casts on the articulator.

Arrangement of artificial teeth. Wax contouring.

5. Trying in the denture. Flasking. Wax elimination. Packing of acrylic

resin. Curing. Laboratory remount. Finishing

and polishing

6. Denture insertion Instructions to the patient

Clinical remount

7. Post insertion care.

Complete Denture

Lecture (2&3)

Objective of complete denture& Maxillary

& Mandibular anatomical landmarks

Zainab Talib Kareem

With Best Wishes




The objective of complete denture:-

1- To restore esthetic and speech.

2- To improve masticatory function.

3- Restore health and comfort to the patient.

4- To have proper occlusion.

Intraoral landmarks of prosthetic importance:

After extraction of teeth, the alveolar bone that supports the teeth begins to resorb and

decrease in size. The part of the alveolar process that remains is called the residual

ridge.

Maxillary anatomical landmarks:

1-Labial frenum :-It is a fold mucosa membrane at the median line ,it contain no

muscles and it starts superiorly in a fan shape .It produces labial notch in the denture .

2-Labial vestibule:-It extends from labial frenum to the buccal frenum on both sides

and it is occupied by the labial flanges of the denture.

3-Buccal frenum :-It is mucosa membrane may be single or multiple ,usually contain

no muscles and it produces buccal notch in the denture .

4-Buccal vestibule:-It extends from the buccal frenum to the hamular notch bounded

medially by the residual ridge and laterally by the cheek and it is occupied by the

buccal flange of the denture and impression.

5-Hamular notch:-It is a narrow cleft situated between the tuberosity and the hamulus

of the medial pterygoid plate .The denture must extend to the hamular notch.

6-Maxillary tuberosity:-The most distal portion of the maxillary alveolar ridge, it

produces a depression in the denture called tubercular fossa.

7-Vibrating line:-An imaginary line across the posterior part of the palate marking the

division between the movable and immovable tissue of the soft palate, located about

2mm in front of fovea palatinae .The distal end of the denture should extend at least

to the vibrating line.

8-Fovea palatinae:-Two small pits or depressions in the posterior aspect of the palate

one on each side of the midline at or near the attachment of the soft palate to hard

palate.

9-Median palatine raphe:-It overlies the median palatal suture, it is a slight elevation

at the midline of the palate extending from the incisive papillae to the deistal end of

the hard palate.

10-Incisive papillae:-This is an elevation of soft tissue covering the incisive foramen

.It is behind and between the maxillary central incisors at the midline, it produced the

incisive fossa in the impression and denture.

*Importance of incisive papillae :-

a-It helps in setting of anterior teeth as it is used for locating the midline.

b-The nasopalatine nerve and blood vessel passes through incisive foramen so care

should be taken that denture base should not impinge on them.

11-Residual ridge:-Because of resoption it is consider the secondary stress bearing

area.

12-Rugae area:-It is the irregular fibrous connective tissue located in the anterior third

of the hard palate .Its consider secondary stress bearing area.

13-Zygomatic process:-Which is located apposite the first molar region and it may

need relief to help in retention and prevent soreness of the underlying tissue.

14-Torus palatines:-This is a hard bone enlargement that occurs in the midline of the

roof of the mouth.

Mandibular anatomical landmarks:

1-Labial frenum:-It is a fold of mucosa membrane it is not usually pronounced as the

frenum in the maxillary arch .The labial frenum produces labial notch in the denture

and impression.

2-Labial vestibule:-It extends from the labial frenum to the buccal frenum on both

sides of midline; it is occupied by the labial flange of the denture and impression.

3-Buccal frenum:-It is fold or folds of mucosa membrane that contains some fibers, it

produces buccal notch in the denture and impression.

4-Buccal vestibule:-It extends posterioly from the buccal frenum to the outside back

corner of the retromolar pad area and from the crest of the residual ridge to the cheek

and it is occupied by the buccal flanges of the denture and impression.

5-Buccal shelf area:-The area between mandibular buccal frenum and anterior edge

of masseter muscle.

6-External oblique ridge:-Is a smooth ridge or line on the buccal surface of the body

of the mandible, it produces the external oblique groove in the denture or impression.

7-Retromolar pad :-Is a triangular or pear shaped pad of tissue at the distal end of the

lower ridge must be covered by the denture to perfect the border seal in the region ,so

it is defined as a posterior landmark for the mandibular denture .It produces

retromolar fossa in the denture and impression .

8-Residual ridge:-Because of spongy bone of mandible the resoption occurs more in

lower residual ridge, it is consider the secondary stress bearing area.

9-Lingual frenum:-It is a fold of mucosa membrane along the floor of the mouth to

the inner surface of the tongue in the midline .It produces lingual notch in the denture

and impression.

10-Alveolingual sulcus:-It is the space between the residual ridge and the tongue

extending from the lingual frenum to the retromylohyoid curtain, it is divided into

anterior, middle and posterior .It is occupied by the lingual flange in denture and

impression.

11-Mylohyoid ridge:-Is sharp and distinct in the molar region.

12-Retromylohyoid fossa:-It is the area posterior to the mylohyoid muscle.

13-Mental foramen:-It is located in the lateral surface of the mandible between first

and second premolar.

14-Genial tubercles:-Rounded elevations clustered around the midline on the lingual

surface of the lower portion of the mandible.

15-Torus mandibularis:-This is a bony prominence usually found bilaterally and

lingually near the first and second premolars.

Fig: (1) land marks of maxillary

Fig: (1) land marks of mandibular

Complete Denture

Lecture (4)

Impression & Materials used in impression

and types of tray

Zainab Talib Kareem

With Best Wishes




Impression:

In dental prosthetics, an impression is a negative registration of the entire denture

bearing area.

An impression is made in order to reproduce a positive form of the oral tissue (cast).

Figure (1): Impression of complete denture.

For construction of complete denture two impressions are needed:

Primary impression:

It is an impression made in a stock tray for making a study cast.

Final impression:

It is an impression made in custom tray constructed on study cast and it is used for

the purpose of making the master cast.

Cast:

It is a positive reproduction of the form of the tissues of the upper or lower arch over

which denture bases or other dental restorations may be fabricated.

Study (diagnostic) cast

A cast formed from a primary

impression for use in diagnosis or the

construction of custom tray.

Figure (2):Study cast

Master (definitive) cast

A cast formed from a final impression and used for fabrication of the prosthesis

Impression trays

An impression tray is a device used to carry, confine and control impression materials

while making an impression.

Impression trays are classified as:

Stock trays made by manufacturers and Custom or Special trays made specially for

one patient and discarded later.

Types of tray:

A. Stock trays

Figure (3): Stock tray

Materials from which the stock trays are constructed

a- Metallic

• Aluminum • Stainless steel

b- Non metallic

B. Custom trays: (Special trays)

They are designed to enable the dentist to make a more accurate and detailed

impression than is possible with stock trays.

Figure (4): Custom tray

Requirements:

1- The tray should be rigid and of uniform thickness (2mm).

2- The tray should simulate the finished denture in size and shape.

3- The border extension of the tray 2mm short of the vestibular depth.

4- The borders should be smooth and rounded.

5- The tray should retain its shape during the impression procedure and pouring of the

impression.

6- It should be easily and rapidly constructed.

7- It should accept trimming.

Construction of special tray:

- All apparent undercuts on the cast are blocked out with base plate wax. -The

exposed areas on the casts are coated with separating medium.

Spacer:

Custom trays are sometimes provided with a spacer to ensure enough space between

the tray and the tissues to allow an even thickness of impression material. The type of

impression material used for the final impressions and impression technique

determines whether a spacer is needed or not and the thickness of spacer to be used.

Figure (5): Spacer technique.

Advantage of the spacer:

It provides a space of even thickness in the custom tray for the impression material

and thus any dimensional change in the material will be equal throughout the

impression.

Figure (6): Prepared cast for special tray.

- The acrylic resin powder and liquid are mixed according to the manufacturer’s

instructions in a glass container. The consistency of the mix is checked periodically

till it reaches the dough stage.

- The dough is placed within a form on a glass slab. It is patted out to form a wafer of

uniform thickness.

- The wafer of the tray material is lifted from the slab and adapted to the cast with

light finger pressure.

- A knife may be used to trim the soft material from around the borders of the cast,

final trimming is done after curing.

- Excess material is formed into a handle of the desired shape. The handle must be

placed so that it will not interfere with any movements of the patient’s lips during

impression procedures.

-Materials used for final impression :

1- Zinc –oxide eugenol impression material.

2- Impression plaster.

3- Rubber base impression the final impression is poured or casted to dental stone.

Final impression are boxed to confine the artificial stone and -: Boxing impression

make pouring the cast easier and preserve the borders of the impression and also

determined the thickness and the shape of the cast .

_Boxing procedure can not be used or impression, made in hydrocolloid materials

(such as alginate and agar agar) because the wax will not adhere to the impression.

Boxing technique ,a strip of boring (beading wax ) as attached all the way around the

outside of the impression approximately (2-3) mm below the border and sealed to it

with a spatula then used a thin sheet of wax which is attached to the beading wax

with from the vertical wall of the boxing ,the vertical wall should extend 10-15 mm

above the impression .

Figure (7): Boxing and pouring technique for impression.

Pouring the final impression and forming the study cast

Materials used for pouring

Artificial stone:

It’s a modified form of plaster of paris which sets even more slowly and produces

casts of improved hardness and strength.

-*Requirements of the cast :

1-Must be smooth and free from any air bubbles or projections.

2-The cast must show all anatomical landmarks and it must be extends few from the

periphery.

3-The thickness of the cast must be at least 15-16 mm.

4-It must be having sufficient strength.

Complete Denture

Lecture(5)

Record base & bite rim

Zainab Talib Kareem

With Best Wishes




Record Bases:-

In completely edentulous situations other means must be provided to record the jaw

relations, these means are the record blocks, which are generally composed of

occlusion wax rims attached to a record base.

Figure (1):- Record base and bite rim

FUNCTION OF THE RECORD BLOCKS

1- Jaw relations recording.

2- Selection of teeth:

• High and low lip lines help in determining the length of the anterior teeth.

• The distance between the two canine lines determines the width of the anterior

teeth.

• The distance between the canine line and the posterior end of the occlusion rim

determine the mesiodistal width of the posterior teeth.

3- Arrangement of teeth.

RECORD BLOCKS

Are composed of record base and occlusion rim.

I. Record base :

Requirements :

It must be reasonably rigid to withstand handling under pressure in the patient’s

mouth.

It must fit the cast accurately in order to keep the same relationship of the occlusal

rim to the cast. An accurate base plate will result in an accurate jaw relation record.

The borders should be developed in the same manner as the borders of the finished

denture.

II- Occlusion Rims:

Occlusion rims are horseshoe shaped blocks of wax which are attached to the base

plate. They are occluding surfaces constructed on temporary or permanent denture

bases to be used in recording jaw relations and for arranging teeth.

Requirements :

1. The occlusion rim must be constructed from a material that is easy to manage.

2. It should be well attached to the underlying base.

3- It must be placed directly over the ridge.

4- It should follow the form of the arch.

5- It should have a smooth surface, and blend smoothly with the facial and lingual

surfaces of the trial base.

6- The sides of the occlusion rim should make a 90o angle with the occlusal surface.

7. Its width must be considerable to permit occlusion of the upper and lower

occlusion rims.

8. The posterior border of the upper rim should terminate at the anterior aspect of the

maxillary tuberosity.While that of the lower rim should terminate anterior to the

retromolar pad.

9. On average, the labial surface of the upper rim should be 10mm anterior to the

incisive papilla.

10. The average height of the upper occlusion block is about 20mm measured from

the depth of the labial frenum to the incisal edge of the upper occlusion rim.

Figure (2): Bite rim

MARKING THE OCCLUSION RIMS:Marks or lines are marked on the record

blocks during jaw relations recording which will aid in the selection and arrangement

of artificial teeth , these lines are :

a-Central line or midline

This line is marked on the upper occlusion rim below the center of philtrum or at the

bisection of the line from corner to corner of the mouth.

b-Canine lines

These lines mark the corners of the mouth when the lips are relaxed.

c-High lip line

The greatest height to which the lip raised in normal function or during the act of

smiling broadly.

d-Low lip line

The lowest position of the inferior border of the upper lip when it is at rest, or, the

lowest position of the superior border of the lower lip during smiling or voluntary

retraction.

Figure (3): Bite rim

Figure (4): Dimension Bite rim

Complete Denture

Lecture(6)

Mounting

Zainab Talib Kareem

With Best Wishes




*Face bow :-It is caliper like device that used to record the relationship of the jaws to

the tempromandibular joint of the jaw and to orient the casts in this same relationship

to the opening axis of the articulator .

-*Face bow consists of :

1-U-shaped frame :-that is large enough to extend from region of tempromandibular

joint to position 5-7cm in the front of the face wide enough to avoid contact with the

side of the face .

2-Condylar rode :-The part that contacts the skin over the T.M.J..

3-The face bow fork :-Attached the occlusal rim and it is attached to the face bow by

means of locking device .

-*Uses of the face bow :

1-Face bow are used to record the anteroposterior and mediolateral spatial position of

the maxillary occlusal surface relative to this transverse opening and closing axis of

the patient mandible .

2-The face bow is then attached to the articulator to transfer the recorded relationship

of the maxilla .

Figure(1): Face bow

Articulator:

An articulator is a mechanical instrument that represents the tempromandibular

joints and jaws, to which maxillary and mandibular casts may be attached to simulate

some or all mandibular movements.

Figure (2): Articulator

FUNCTIONS

1. The primary function of the articulator is to act as a patient in the absence of the

patient.

2. Articulators can simulate, but they cannot duplicate, all the possible mandibular

movements.

3. Mounting dental casts for diagnosis and treatment planning.

4. Fabrication of occlusal surfaces for dental restoration.

5. Arrangement of artificial teeth for complete and removable partial dentures.

ADVANTAGES :

1. Visualization of the patient’s occlusion especially from the lingual side.

2. Patient cooperation is not a factor once the appropriate inter occlusal records are

obtained from the patient.

3. Considerable chair time and patient appointment time is saved.

4. The patient’s saliva, tongue, and cheeks are not factors when using an articulator.

Minimal articulator requirements:

1. The articulator must accurately maintain the correct horizontal and vertical

relationship of the patient’s casts.

2. The casts must be easily removed and attached to the articulator without losing

their correct relationship.

3. The articulator should have an incisal guide pin with a positive stop to preserve the

patient’s vertical dimension.

4. The articulator should be able to open and close in a hinge like fashion.

5. The construction should be accurate, rigid, and of non-corrosive material.

6. The moving parts should resist wear. The adjustment should be able to move freely

and be definitely secured. The articulator should be stable on the laboratory bench

and not too bulky and heavy.

Mounting :

A laboratory procedure of attaching the maxillary and or the mandibular cast to an

articulator or similar instrument.

Mounting procedure:-

1-Maxillary cast is mounted in a semiadjustable articulator with help of orientation

jaw relation record.

2-Support the bite plane with cast support to carry the additional weight.

3- Maxillary cast is made flat and V-shape notches are prepared on the mounting

surface at the periphery . This surface is lubricated with thin coat separating medium .

Figure (3): V-shape notches

4-The cast is then securely seated in the denture base with the Occlusal rim firmly

resting in bite fork imprint.

5-Mixture stone place on the cast, the upper member is closed to the upper cast to

bring the incisal pin into contact with incisal guide

Figure (4): Mixture stone place on the cast

6-Mandibular cast is mounted using an inter-Occlusal record.

Figure(5): Mandibular cast is mounted

Figure(6):Maxillary & Mandibular cast is mounted

Figure(7):Articulator represent the T.M.J

Complete Denture

Lecture(7)

SELECTION OF ARTIFICIAL TEETH

Zainab Talib Kareem

With Best Wishes


ات الاسنانينقسم تق


SELECTION OF ARTIFICIAL TEETH

Teeth selection is very important as the selection of the appropriate shade, size, and

form of the artificial teeth determines the esthetic and function of the denture.

Requirement of selection of artificial teeth

1-The teeth should be in harmony with the surrounding tissues.

2-They should maintain the vertical dimension.

3-They should be efficient for mastication.

4-Anterior teeth are selected predominantly based on esthetic, whereas the posterior

teeth should be selected based on the function.

NOT:Anterior teeth are primarily selected to satisfy esthetic requirements, so the

dentist's professional obligation is to give the patient adequate information, guidance,

and opportunity to choose their teeth. Anterior teeth selection is the area of

prosthodontics care in which the patient should be given a primary responsibility to

determine the esthetic outcome.

Consideration to selection of artificial teeth:-

A- SHADE (COLOR)

1-It is the degree of darkness of the color. There are two basic shades, the yellow

and grey, and the other shades vary in between. Many patients will ask for very light

shade, tell them that the proper shade gives more natural appearance, never force the

patient to accept a shade that they do not want, they will never be satisfied with the

denture.

The younger the patient, the lighter the shade is preferred. The shade of natural teeth

will be darkening with age because of

1-Deposition of secondary dentin.

2-Consequent reduction in size of the pulp chamber.

3-Wearing a way of enamel.

4-External staining of the exposed dentin from oral fluids, foods, or tobacco.

2-The color of the face should harmonize the shade of the teeth. Lighter teeth are

suitable for lighter skin, while darker teeth are suitable for darker skin. Although

people with dark skin seemed to have very light teeth, this is because of contrast in

the skin and teeth color.

B- SIZE

To select the size of teeth, we have to consider the following:

A-The length of anterior teeth is controlled by:

-2 mm seen from the maxillary central incisors.

B-Length of mandibular anterior teeth should be with the level of lower lip.

When the space is available, it is more esthetically acceptable to use a tooth long

enough to eliminate the display of the denture base (teeth are more attractive in

appearance than denture base materials).

C-The width from the tip of left canine to the tip of right canine is almost equal to the

width of the nose (interalar width) when measured by the caliper. (Width of six

anterior teeth = interalar width + 7 mm)

D-The width of maxillary central incisor equals approximately to 1/16 of bizygomatic

width, and the width of maxillary anterior teeth equals to 1/3.36 of bizygomatic

width.

E-Width of the anterior teeth can be measured on maxillary occlusal rim depending

on the intraoral anatomical landmarks like: (buccal frenum, corner of the mouth, and

canine eminence).

Fig (1): selection the width of anterior teeth

C- SHAPE (FORM)

square, ovoid, and tapering. The maxillary central incisor form should be in harmony

with patient face.

central incisor convex concave viewed from mesial aspect should be in harmony with

profile of face.

Allow the patient to select between the same size teeth but different forms. Set two

different forms of teeth on the right and left sides of a piece of wax rope, and ask the

patients which they prefer.

Fig(2): form tooth according form of face.

NOTE: The buccolingual width of posterior teeth should be slightly narrower

than natural teeth, because the broader occlusal surfaces which direct more stress

during function to supporting tissue, leading to increase in the rate of ridge

resorption. Broader teeth encroach into the tongue space leading to instability of the

denture. Also, the teeth should not encroach into the buccal corridor space to avoid

cheek biting.

The narrow artificial posterior teeth enhance the development of the correct form of

the polished surfaces by allowing the buccal and lingual denture flanges to slope

away from the occlusal surface.

Occlusal form of posterior teeth:-

There are two forms

a-They have anatomical teeth have cusp

b-They also called monoplane, flat plane, or zero degree.

a-Anatomical teeth:-

1-More efficient in chewing.

2-They can be arranged in balanced occlusion in

eccentric position.

3-The cusp fossa relationship between the

maxillary and mandibular posterior teeth forms a

definite point for return to centric occlusion. Fig(3): anatomical teeth

4-More acceptable esthetically.

5-More compatible with surrounding oral environment.

b-They also called monoplane, flat plane, or zero degree.

1-Offer less resistance in non-masticatory movement

like (bruxism); therefore less damaging to the

supporting structure.

2-More comfortable.

3-Offer less resistance to lateral forces therefore, they

are indicated in excessively resorbed ridges.

4-Allow greater range of movement which is

necessary in patient with malrelated jaws. Fig (4): monoplane teeth

5-They can be used with less damaging effect than cusp form teeth in patient with

uncoordinated neuromuscular control which jaw relation records are not repeatable.

TYPES OF TEETH

1- Acrylic teeth (They are made from acrylic resin).

2-Porcelain

1- Acrylic teeth(They are made from

acrylic resin).

2-Porcelain

a-They are not brittle, but poor abrasion

resistance, so they might become worn

down with consequent loss of vertical

dimension.

b-Esthetic very good, but cannot

maintain luster for long time.

c-Chemical bonding with denture base

d-Easily ground and polished.

e-Transmit less force to mucosa because

they have greater resilience, so they

cushion the underlying supporting tissue

from occlusal load.

f-There is no clicking during contact.

j-Thermal expansion same as that of

acrylic denture base.

h-Preferred when there are natural

opposing teeth or gold bridge or when

there is insufficient interocclusal

distance where insufficient place to

accommodate the holes and pins to

secure the mechanical anchorage of

porcelain teeth, and grinding become

necessary.

a-They are brittle and thus susceptible to

fracture, more resistance to abrasion.

b-Excellent esthetic, does not stained,

and maintain luster for long time.

c-Mechanical bonding by pins or

undercut holes.

d-Difficult to grind and polish.

e-More forces transmit to the mucosa.

f-There is clicking during contact.

j-Thermal expansion is much lower than

acrylic causes stresses in acrylic denture

base and crazing may appear around

teeth.

h-Preferred for young patient, because it

look more vital, smooth, and difficult to

abrade, and maintain luster for long

time.

Lecture (8&9)

Arrangement of upper and lower (anterior

& posterior) teeth

Zainab Talib Kareem

With Best Wishes




OCCLUSAL CURVATURES

Occlusal curvatures or curves of occlusion: This is a curved occlusal surface that

makes simultaneous contact with the major portion of the incisal and occlusal

prominences of the existing teeth.

Figure (1): Occlusal Curvatures

General Considerations for the Arrangement of Teeth:

1. Maxillary teeth:

Anterior teeth

Important factors must be considered when arranging anterior teeth:

a. Esthetics:

In order to restore the natural looking and contour of the facial structure, it is

important to notice the shape and contour of the lips, mouth, and muscles of facial

expression, as these depend on the positioning of the teeth and the contour of the

base.

b. Phonetics:

Speech is affected by the position of the teeth, the contour and bulk of the denture

base material about the lingual aspect of the teeth, and the thickness of the palate.

Posterior teeth:

Important factors must be considered when arranging posterior teeth.

a. The crest of the lower ridge:

The arrangement of upper posterior teeth is governed by the position of the crest of

the lower ridge. The central groove of each upper posterior tooth is placed parallel to

and directly over this crest. The crest of the lower ridge is indicated by a straight line

drawn on the cast

b. Common horizontal plane:

The occlusal surfaces of the right and left posterior teeth must be on the same

horizontal plane or level.

c. Spacing of posterior teeth:

The posterior teeth are arranged with a broken contact. The distance between the

canine and first premolar is 0.5 mm. The other posterior teeth are spaced by about

0.25 mm in order to:

• Permit change in position of upper posterior teeth when arranging the lower

posteriors to articulate with them.

• Prevent a crowded arrangement that might make it difficult to position the lower

first premolar.

• Permit slight tooth movements brought about by pressure created during packing

and processing of acrylic resin.

2. Mandibular teeth:

Anterior teeth

In arranging lower anterior teeth esthetics, phonetics, and incision must be considered

as in upper anterior teeth.

Posterior teeth

The mandibular posterior teeth must be arranged to contact the maxillary posterior

teeth in a balanced occlusion to obtain equilibrium of the denture.

Sequence of Teeth Arrangement:

The sequence in which artificial teeth are arranged is not as important as the end

result. There are many acceptable methods for arranging artificial teeth. Most of these

methods begin with the arrangement of the maxillary central incisors, as they

maintain the central line; the remaining maxillary anteriors are then arranged in

sequence.

One of the popular sequences of arrangement is to set all the maxillary teeth first,

then the mandibular posteriors starting with the second premolar placed to occlude

with the upper 4 and 5 and lastly the mandibular anteriors.

Anterior of the upper teeth:

The central incisor:

Its long axis is parallel to the vertical axis or inclined slightly to the distal when

viewed from the front, and sloping slightly labially when viewed from the side. The

incisive edges are in contact with the occlusal plane.

Figure (2): Arrangement & long axis of central incisor

The lateral incisor:

Its long axis is inclined distally when viewed from the front, and inclined labially

when viewed from the side. The neck is depressed although the labial surface will be

nearly in line with the central incisor. The incisive edge is 0.5 to 1mm above and

parallel to occlusal plane.

Figure (3): Arrangement & long axis of lateral incisor

The canine:

Its long axis may be parallel or slightly distally inclined to the vertical axis when

viewed from the front, and vertical when viewed from the side.

Figure (4): Arrangement &long axis of canine

Its cusp tip is in contact with the occlusal plane. The neck is prominent as it

forms the corner of the patient’s mouth. The canine has two planes on the labial

surface. The mesial plane should follow the contour of the anterior teeth, while the

distal plane should be in line with the posterior teeth.

Figure (5): Canine prominent

The first premolar:

Its long axis is parallel to the vertical axis when viewed from the front and side. The

buccal cusp is touches the occlusal plane, while the palatal cusp raised nearly 0.5 mm

from the occlusal plane.

The second premolar:

Its long axis is parallel to the vertical axis when viewed from the front and side. The

buccal cusp and palatal cusp touches the occlusal plane.

The first molar:

Its long axis is inclined slightly to the mesial when viewed from the front. The

mesiolingual cusp touch the occlusal plane and mesiobuccal cusp above the occlusal

plane about 3/4mm.

The second molar:

Its long axis is inclined to the mesial when viewed from the front. All the four cusps

are short of the occlusal plane.

Figure (6): Arrangement of posterior teeth

Anterior & Posterior of the lower teeth:

The central incisor:

Its long axis is parallel to the vertical axis when viewed from the front and slopes

labially when viewed from the side. The incisal edge is parallel to and 1mm above the

occlusal plane, to establish vertical overlap of the maxillary anterior.

The lateral incisor:

Its long axis is parallel to the vertical axis or inclined slightly to the mesial when

viewed from the front. While from the side, it is inclined labially. The incisal edge is

parallel to, and also 1mm above the occlusal plane.

The canine:

Its long axis leans slightly towards the midline when viewed from the front. While

very slightly lingually, when viewed from the side. Its cusp tip is at the same plane as

the incisal edges of the central and lateral incisors 1mm above the occlusal plane to

establish vertical overlap of the maxillary anteriors.

Figure (7): Arrangement of lower anterior teeth

***Over bite (vertical overlap):-The amount of vertical overlaps of the upper

anterior to lower teeth and should be 1-2mm.

***Over jet (horizontal overlap):-Is the horizontal space between the palatal

surface of the upper anterior teeth and labial surface of the lower anterior teeth

and should be 1-2mm.

Figure (8): Vertical overlap & horizontal overlap

The mandibular posterior teeth must be arranged to contact the upper posterior teeth

without interference (balanced occlusion).

Figure

(9):

Arrangement of lower posterior teeth

Figure (10): Arrangement of lower posterior teeth in articulator

Complete Denture

Lecture (10)

TYPES OCCLUSION

Zainab Talib Kareem

With Best Wishes




TYPES OCCLUSION Over bite (vertical overlap):-The amount of vertical overlaps of the upper anterior to

lower teeth and should be 1-2mm.

Over jet (horizontal overlap):-Is the horizontal space between the palatal surface of

the upper anterior teeth and labial surface of the lower anterior teeth and should be 1-

2mm.

Cross bite: - Malocclusion or misalignment of teeth where upper teeth fit inside of

lower teeth. This case can affect a single tooth or groups of teeth, involving the front

teeth, back teeth, or both.

*Characteristic of class I occlusion:-

1-The most retruded position of the mandible to the

maxilla.

2-Normal occlusion because normal over jet (1-2 mm) and

normal over bite (1-2mm).

3-The mesiolingual cusp of upper first molar in the central

fossa of the lower first molar.

4-The upper teeth over lap the lower teeth.

Fig:(1) class I occlusion

*Characteristic of class II occlusion :-

1-Sever retruded of mandible to the maxilla .

2-Abnormal occlusion because of increase of over jet

between incisor ,

3-The mesiolingual cusp of upper first molar in the

embrasure between the second premolar and first molar

of lower teeth .

4-In these class we found cross bite and these may be

unilateral or bilateral cross bite .

Fig:(2) class II occlusion

*Characteristic of class III occlusion : -

1-Protruded of the mandible to the maxilla , the relation of the mandible as forward to

the maxilla .

2-Edge to edge because over jet is zero , the lower anterior incisor over lap the upper

incisor .

3-The mesiolingual cusp of the upper first molar in the embrasure between the first

and second lower molar .

4-In these case may have anterior cross bite and the upper arch may be smaller than

lower arch .

Fig:(3) class III occlusion.

Fig:(4) Types of occlusion.

Complete Denture

Lecture (11)

Posterior palatal seal(post dom)

Zainab Talib Kareem

With Best Wishes




Posterior palatal seal (post dom):-

The seal area at the posterior border of the maxillary denture and called also (post

dom) .While the posterior palatal seal area is the soft tissue at or beyond the junction

of the hard and soft palates on which pressure within physiologic limits can be

applied by the denture to aid in its retention .

*The posterior palatal relief is a depression carved in the cast which improves

retention of the maxillary denture .

Fig: (1) post dom on cast. Fig: (2) post dom of patient mouth.

*It is carved just forward to the posterior border of the denture –The vibrating line of

the soft palate normally used as a guide to the ideal posterior border of the denture

which is located slightly anterior to the fovea palatinae.

And this line can be determine by asking the patient say (Ah) thus vibrate the soft

palate .

--Then V-shape groove (1 -1.5mm) deep is carved into the cast and this groove will

form bead on the denture that provide the posterior palatal seal .

--The bead will be 1 -1.5mm high and 1-1.5mm wide at its base and the shape look

like butter fly.

--By a sharp instrument, such as the spoon shaped end of a roach carver or by sharp

knife or lacron is used to carve the posterior palatal relief.

Fig: (3) Making of post dom on cast

*Where are you placed the post dom?

a-The denture ends on the cast.

b-Located of post dom (2mm) in front of the vibrating line ,is extended laterally

through the center of hamular notches.

Note:-the vibrating line and width of posterior seal depend on the thickness of the soft

palate.

Fig: (4) post dom dimension

*Advantages of posterior palatal seal:-

1- Provide more retention.

2- To give posterior palatal seal.

3- Provide seal against air being forced under the denture.

4-Thickness area provides strength across the denture.

5- Prevent insertion food between the denture base and underlying tissue.

Types of posterior palatal seal :-

Fig : (5) Types of post dom.

Errors in complete denture a related to the post dom:-

1-A greater width creates an area of tissue placement that will have, tendency to push

the denture downward gradually and the defect the purpose of the posterior palatal

seal.

2-If the bead has been made too high the sharpness will make this apparent within 24

hours of the insertion of the denture and it can be easily relieved.

3-The narrowness of the bead makes the seal with minimal downward pressure on the

denture.

4-Some spots at the posterior palatal seal :-

a-That into deep .

b-Too sharp .

Note:-so adjustment must be made very carefully to prevent loss of the border seal

5-If more long extended the soft palate causes gag reflex and vomiting .

6-If short lead to dislodgment the denture .

Notes :-

1-If found or more shallow the post dom should be (repost dom ) by take impression

.By the final denture and pouring new master cast and marking the correct position of

post dom in the mouth and it is location is transferred on the cast after this stage

should be carved in the cast which improve the retention of the material denture.

2-If the special tray not reach to correct position of post dom (short ) should be add

tracing complete at the final impression.

3-If the base plate not reach to position of post dom should be make extension reach

to location of post dom by cold cure acrylic resin.

Complete Denture

Lecture (12,13)

Waxing & Carving Procedures

Zainab Talib Kareem

With Best Wishes




Waxing :-The contouring of the wax pattern of a trial denture in to the desired form

there are two methods of waxing (Drip on ,Press on)

Drip on waxing:-

A portion of sheet wax of base plate wax is softer and rolling into a wax stick a little

larger than the diameter of a lead pencil.

The wax stick is heated on the Bunsen burner flame and then the molten wax on the

end of the stick is dripped on the denture base .

The wax may be built up around the teeth and the border by this method .

Press on waxing:-

Placing wax on the denture base is to soft the entire stick of base plate wax and to

mold this into place with your finger .

The objective of either the drip on of press on method is to add a sufficient bulk of

wax to the denture base which can then be carved to the proper contour .

_Excessive bulk should be avoided because that lead to poor esthetic and increase

porosity but thin denture also not recommended because they also lead to lack

adequate strength and less dimensional stable than thicker .

Complete denture consists from three surface divided to :-

1- The occlusal surface. 2- The polished surface. 3- The fitting surface.

_The polished surface ( buccal ,labial and lingual surfaces of the teeth and the buccal

and lingual surfaces of the base).

Waxing procedure:-

1-Small end of knife is held at (45o) degree angle to the tooth surface to form the wax

gingival margin.

2-Triangular marking can be placed as a guide to the length and position of the root.

3-The root of maxillary canine is longest ,the root of lateral incisor is shortest and the

root of central incisor is between these two.

4-On the mandibular denture the root of the canine is longest ,the root of central

incisor is shortest and the root of lateral incisor is between these two.

5-The anterior portion of the maxillary denture base replace tissue lost through

resorption , excessive thickness usually indicated improper placement of anterior

teeth.

6-The border of the denture should be rounded.

7-The palatal surface of the maxillary denture should be waxed to uniform thickness

of 2.5 mm.

8-The contour of the mandibular denture aid in retention ,in the anterior region the

facial surface is relatively straight .The lingual surface slop to the lingual border and

it is relatively straight .

9-The buccal and lingual border of the mandibular denture should be make concave

so that the tongue and cheek will grip and tend to seat the denture .

10-If the buccal and lingual border of the mandibular denture are made convex this

will tend to inclined plane force resulting from the pressure of the tongue and cheek

will tend to unseated the denture .

Fig(1):waxing procedure

Carving:- It is the process by means of which gingival portion of complete denture

that simulate natural gingival contours.

Festooning procedure:-

1-A sharp instrument is used to cut back the wax a round the cervical line on the

artificial teeth.

2-Reduce the ledge from a round the tooth in the previous step to width of (1-

1.5mm), the narrow ledge carved a round the teeth extended a round the entire dental

arch.

3-Torch is used to smooth the facial contours of the surface denture base.

4-Carving to simulate the lingual are placed, the palatal surface is also smooth.

5-Wax solvent is used to clean any wax film the surface of the teeth.

Fig(2): Festooning

Errors of festooning :-

1-inter dental papilla not existing or too small .

2-fine detail not incorporated in the wax up .

3-place groove on the denture base between each tooth which food tends to back and

also make the denture difficult to polish.

Stippling :-it is carving of the wax to simulate natural gingival and prevent light from

being reflected from the denture base.

Procedure

1-Stippling in the wax denture base is done by first lightly flaming the surface of the

wax ,the wax base is then sruck repeatedly with stiff tooth –brush and produce many

small indentation in the wax.

2-The wax denture base should be stippling only where the base will show when the

patient talks and smiles ,this area should be indicated by the dentist .

3-Astippling denture base is not as hygienic as a polished base ,and therefore should

be avoided when not necessary or if the patient does not have good oral hygienic

habits .

Fig(3): Stippling procedure

Disadvantages of stippling :-

The stippling lead to accumulation of food deposit that then lead to poor esthetic to

the patient.

Complete Denture

Lecture (14)

Flasking procedure

Zainab Talib Kareem

With Best Wishes

ير صناعة الاسنانزينب طالب كريم /ماجست



Flasking

Is the process of investing the cast and wax pattern in a flask to form a mold to the

restoration, material that is going to be used of acrylic resin (polymethyl

methacrylate).

Procedure :-

bases the trial denture to or lower carefully seal the upper -:Preperation the cast -1

and separate the cast from the mounting ,remove any excess mounting plaster from

the cast.

Fig(1): Separation the cast from articulator.

2-The trial denture is tested in the flask to determine its height in relation to the

height of the bottom half of the flask .The top half of the flask is placed in position to

determine whether the teeth are too high in relation to the top of the flask

approximately 3-6mm of space should be available between the teeth and the top of

the flask .If the teeth are too high ,the cast must be reduced in thickness .The distal

end of the lower cast may be high in relation to the reminder of the cast and extend

close to the posterior edge of the flask this condition causes the distal ends of the cast

to be an acute angle to the rim of the flask .thus the distal end are available to

breakage and careful consideration is demanded in reducing this angle so that the top

half of the flask will separate easily .

Fig(2): Check the Flasking.

3-Painted the casts with separating medium or place a light coat of Vaseline on the

inner surface of the entire bottom flask.

4-Mix sufficient artificial stone and then placed in the bottom half of the flask ,and

the cast has been painted with separating medium is placed down into the stone until

or nearly on a level with the top edge of the flask ,the stone is leveled to a line

between the edge of the cast and the rim of the flask ,don’t permit stone to cover the

waxed area of the denture base after the stone set .

Fig(3):Mix sufficient artificial stone and then placed in the bottom half.

5-Now separating medium has been applied to the exposed stone in the flask ,a core

of the artificial stone 2-4 mm in thickness is developed around the labial and buccal

surface of the both upper and lower dentures also on the lingual surface of the lower

wax denture and the palatal surfaces of the upper wax denture , the top of the core

should be 2-3 mm below the occlusal plane of the teeth .

Fig(4): Placing Vaseline.

6-Separating medium is applied on the exposed surface of stone core and the top half

of the flask is placed in position .Then a mix of artificial plaster (stone ) is powered

up to the level of the incisal edges of the anterior teeth and the tip of the cusps of the

posterior teeth after set the exposed stone (plaster ) painted with separating medium

,then the flask is completely filled with stone ,and the lid of the flask is placed in

position, some stone should pass through the holes of the lid and leave to set.

Fig(5): Applied the second layer of stone.

Complete Denture

Complete Denture

Lec(15,16)

Waxing elimination & packing procedures

Zainab Talib Kareem

With Best Wishes




WAX ELIMINATION

Is the process of removing the wax from the flask and this done by putting the flask

in boiling water for short period of time .

Procedure :-

After the stone is used in full flasking ,(has reached its final set approximately 45

min).The wax must be eliminated to form a mold into which resin may be packed .

*Clean boiling water must be used for wax elimination procedure ,any residual wax

in the mold will contaminate the acrylic resin and till prevent bonding between

acrylic resin teeth and denture base .

1-Place the flask in boiling water on allowed to remain for 5 minutes.

Note:- The time required for melting wax in a flask depend on upon the size of the

flask and the temperature of the water .

Fig(1): Putting the flask in boiling water

2-The flask is removed from the water and opened from side opposite the greatest

undercut of the cast(removed the softened wax and temporary denture base ).

3-After the flask is opened the surplus wax washed out with a stream of boiling water

Fig(2): Opened the flask.

4-When the water has been drained from the flask the mold is washed again with a

boiling water containing a detergent and then again with clean boiling water .

Fig(3): Washed the flask.

5-After the stone is dry,but still hot ,the inside of the mold is painted with a tin foil

substitute to prevent acrylic from adhering on the stone ,a tin foil substitute must not

come in contact with teeth or pool in the mold ,the tin foil substitute is allow to dry

and a second coat is painted on the inside of the mold ,the flask is allowed to cool to

room temperature .

Fig(4):Applied separating medium.

PACKING

It is the act of filling a mold with denture base material with in flask.

Packing procedure :-

Mix the acrylic liquid (monomer) and powder (polymer) in proper ratio(1:3) when the

acrylic reaches the dough stage , the acrylic resin dough is formed in to a cylindrical

mass and cut into pieces of the approximate size of the mold ,the pieces are

positioned around the buccal ,labial and palatal surfaces of the upper mold and

around the buccal, labial and lingual surfaces of the lower mold .

The flask is closed in a press with a pieces of separating paper between the two

halves until there are into the close contact then the flask is opened ,the excess resin

is removed and additional resin is added at any places that are de-finished ,this step

should be repeated until the mold is filled and no excess is formed .

The flask is closed completely without the separating sheet .The flask is transferred to

the spring clamp .The clamp is closed lightly but not full compressed ,this allows the

resin to expand upon processing and then finally contract while still under pressure.

**We use the dough stage of acrylic resin In the packing procedure for several

reasons :-

1-If its packed at the sticky stage ,too much monomer will be present between the

polymer particles ,the material will be of too low viscosity to pack well ,and will

follow out of the flask too easily.

2-If its packed at the rubbery stage ,too stiff stage ,the material will be too viscous to

follow well under the pressure of the flask press and metal to metal contact of the

flask halves will be not obtained .

Fig(5): Packing procedure.

Documents

Complete Denture Terminologies & Introduction