REVISION (1) B.M.C

REVISION (1) B.M.C

**CHAPTER. (1) INTRODUCTION

The art and science of supplying artificial replacement for missing parts of the human body.

An artificial replacement of an absent part of the human body.

It is the dental specialty pertaining to the diagnosis, treatment planning, rehabilitation & maintenance of the oral function, comfort, appearance and health of patients with clinical conditions associated with missing/deficient teeth &/or maxillofacial tissues using biocompatible substitute.

2

1

1- Denture base

2- Artificial teeth

Components of complete denture

Denture surfaces

1- Denture basal surface:

2- Denture polished surface:

3- Denture occlusal surface

Clinical Laboratory1. Examination & Diagnosis

2. Primary impression Study cast Special tray

3. Final impression Boxing and pouring master cast Occlusion blocks

4a. Jaw relation registration4b. Selection of artificial teeth

Mounting on articulator Setting of artificial teeth and waxing up

5. Try in Processing

6. Insertion

7. Post insertion care

Objectives of complete denture

• 1-Restoration of the function of mastication to restore the normal digestive process

• 2- Appearance (esthetics) restoring the normal appearance of the face especially the lower third of the face.

►Loss of teeth (especially anteriors) Speech Defects►The artificial teeth should be placed in a positionpreviously occupied by the natural teeth.

**CHAPTER. (2) LANDMARKS

Changes That Happen After Teeth Loss :

Face :

Anatomical Landmarks In Relation To Complete Denture :

Inter pupillary line

Ala Tragus Line

Modulus

Naso – Labial sulcus

Labiomental sulcus

Extra Oral Landmarks

Inter pupillary line

Ala Tragus line

Naso – Labial sulcus

Modulus

Labiomental sulcus

Anterior Occlusal Plane Determination

Classes of jaw relations

Becomes deeper with age and with loss of teeth

Posterior Occlusal Plane Determination

Become Flat With The Loss Of Teeth

Denture Bearing areas / Upper Incisive Papilla

Incisive Papilla

1 . The incisive papilla is a thick part of the mucous membrane covering the incisive foramen.

2 . It is located at the anterior end of the median palatine raphae .

3 . The nasopalatine nerves and vessels pass through the incisive foramen to supply the anterior 2 / 3 of the palate.

4 . In some cases due to the excessive bone resorption, the papilla may lie on the crest of the ridge.

5 . The incisive papilla should be relieved to avoid pressure on the incisive nerves and vessels. CAUSING BURNING SENSATION IN THE ANT. 2/3 OF PALATE

Intra Oral Landmarks

Denture Bearing areas / Upper

Raugae Area

Palatine Rugae

1 . It is an irregularly shaped elevations of soft tissue extending laterally from the midline in the anterior part of the hard palate.

2 . It serves as one of stress bearing areas in the palate .


Median Palatine Raphae

Median Palatine Raphae

1 . The midline of the hard palate is covered by a thin layer of mucoperiostium , that covers the median palatine suture . 2 . That suture joins the right and the left halves of the hard palate.

3 . It is usually relieved to increase denture stability by preventing its rocking .


Fovia Palatina

Fovia Palatina

1 . It helps in the determination of the posterior border of the upper denture.

2 . The posterior border of the upper denture should be 2 mm posterior to the fovea Palatina .

Residual Alveolar Ridge

To Continue ( Bearing Areas)

Residual Alveolar Ridge

1 . It should be firm specially in the lower ridge .

2 . It covers the crest of the lower ridge.

3 . Its mobility may cause pressure symptoms under the lower denture.

4 . Also can affect denture stability .


Buttress Part Of Bone

Buttress Part Of Bone

1 . It is formed of the lower portion of the zygomatic process of the maxilla (the area above the first molar teeth) .

2 . It provides excellent resistance to the vertical forces(Support).


Tuberosity

Tuberosity

1 . It is important for retention and support of the upper denture against lateral movement.

2 . The denture should cover it , because it is one of stress bearing areas in the upper jaw .

Immovable Part of Soft Palate


Immovable Part of Soft Palate

1 . The immovable part lies adjacent to the hard palate and the movable part lies more posterior.

2 . The posterior edge of the upper denture should end at the junction of these two parts .

Labial Frenum

Denture Limiting Structures (Upper)

Labial Frenum

It must be relieved in the denture by making a V-shape notch in the labial flange opposite to its position .

Labial Vestibule


Labial Vestibule

1 . It Is the reflection of the mucosa of the lip to the mucosa of the alveolar process in the labial vestibule.

2 . The denture in this area is in relation to the orbicularis oris and the superior incisive muscles .

3 . These muscles limit the thickness and the length of the labial flange of the denture.

Buccal Frenum


Buccal Frenum

1 . It is a fold of mucous membrane (tendon of the buccinator muscle) varies in size in number and in position .

2 . A notch is made in the denture flange opposite to its position to facilitate its functional movements.

Buccal Vestibule


Buccal Vestibule

1 . The denture in this area is related to buccinator muscle.

2 . Buccal flanges must extend in the buccal vestibule .

3 . Due to the horizontal direction of the fibers of this muscle; the contraction of this muscle will not displace the denture.


Hamular Notch

Hamular Notch

1 . It is one of the important landmarks for determination of the posterior limit of the upper denture .

2 . A straight line from hamular notch on one side to the other on the other side determines the posterior limit of the upper denture

Vibrating Line ( Ah Line)


Vibrating Line ( Ah Line)

1 . It separate the movable part from the immovable part of the soft palate.

2 . This line is 2mm posterior to the fovea palatine .

3 . This line determines the posterior end of the upper denture.

Retro Molar Bad

Denture Bearing and Limiting Structures (Lower)

Retro Molar pad

1 . It is a pear shaped area of mucous membrane at the posterior end of the mandibular ridge and anterior to the pterygo mandibular raphae .

2 . It consists of mucous glands , temporal tendon , fibers of the buccinators and superior constrictor muscle .

3 . Lower denture should cover this area for retention and to cover the buccal shelf of bone.

Buccal Shelf Of Bone


Buccal Shelf Of Bone

1 . The area that lies between the crest of the residual ridge and the external oblique ridge.

2 . It is the primary stress bearing area in the lower arch .

3 . It forms good support for the lower denture .

Buccal Vestibule


Buccal Vestibule

1 . The denture in this area is related to the buccinator muscle .

2 . Its contraction does not displace the lower denture so flanges of the lower denture must extend in the buccal vestibule.

Buccal Frenum


1 . It is a fold of mucous membrane in the premolar area, movement of the lip and the cheek move the frenum .

2 . A notch is made in the lower denture to accommodate the frenum.

Buccal Frenum

Labial Vestibule

Labial Frenum


Labial Frenum

Labial Vestibule

Residual Ridge


Residual Ridge

Lingual Pouch


More posteriorly the lingual flanges are related to the lingual pouch with its boundaries which are : Posteriorly : The palatoglosssus muscle . Anteriorly : The Mylohyoid muscle. Medially : The tongue . Laterally : The medial aspect of the mandible.

Lingual Pouch

Sublingual salivarygland area


Sublingual salivarygland area

The lingual flanges of the lower denture should not extend in this area because with excessive resorption of the mandible the gland maybulge superiorly above the body of the mandible.

Lingual Frenum


Lingual Frenum

1 . More anteriorly a fold of mucous membrane attach the mucosa of the tongue to mucosa of the floor of the mouth

2 . It moves with the movement of the tongue so a notch is made to accommodate the frenum.

**CHAPTER (3) IMPRESSIONS

Types of Trays

I- Stock trays

II- Custom trays (Special, Individual trays)

The body and handle are designed to suit different mouths

1-Dentulous mouth cases

.

2-Edentulous mouth cases

.

3-Partially edentulous mouth cases.

Types of special trays

1- Shellac base plate special tray 2- Acrylic resin custom (special) trays: a- cold cured b- heat cured c- light cured Both heat and cold cured are used widely now. It is rigid and

light in weight, not wrap in the mouth . 3- Cast or swaged metal tray 4- Vacuum formed plastic sheets It needs a pressure forming machine

Comparison between shellac and acrylic resin custom trays

• Shellac base plate special tray

1. Low strength.2. Easily distorted by load

and temperature.3. Improper adaptation to

the cast4. Easily constructed

Self-cured acrylic resin special tray

1. Higher strength and rigidity.2. Not distorted by temperature.

3. Well adapted

4. Easily constructed

Tray can be

1- with a spacer

2- without a spacer

SHIM OR SPACER

“ One thickness of modeling wax or shellac base plate adapted on the study cast under the special tray “

Custom Tray With Spacer

Impression

Impression is a negative likeness or copy. Cast is a positive copy

Preliminary (primary) impression

Is defined as: a negative likeness made for the purpose of diagnosis, treatment planning, or fabrication of a special tray.

Preliminary (study) cast is defined as: a cast formed from a preliminary impression for use in diagnosis or the fabrication of a special tray.

Final (secondary) impression

“The impression represents the completion of the registration of the surface or object.

It is an impression which is used for making definitive (master) cast. “

(1) IMPRESSION TECHNIQUE

MINIMAL PRESSURE ( MUCOSTATIC)

FUNCTIONAL PRESSURE (MUCOCOMPRESSIVE) SELECTIVE PRESSURE

(2) PHILOSOPHY ALL THE TISSUES ARE UNDER THE LEAST PRESSURE.

ALL THE TISSUES ARE UNDER FUNCTIONAL PRESSURE.

TISSUES THAT CAN WITHSTAND PRESSURE ARE LOADED. AND TISSUES THAT CAN'T ARE RELIEVED.

(3) TRAY PERFORATED + ON SPACER + WITH TISSUE STOPS.

WELL ADAPTED + NO SPACER + WAXRIM.

STOCK TRAY WITH COMPOUND ,THEN IT IS RELIEVED AND WASHED WITH PLASTER IMPRESSION MATERIAL.

(4) PRESSURE FINGER PRESSURE PATIENTS BITING FORCE. FINGER PRESSURE.

(5) IMPRESSION MATERIAL PLASTER, FLOWY MATERIAL. ZnO/E , HEAVY MATERIAL IMPRESSION COMPOUND (HEAVY)+ PLASTER OR ZnO/E(FLOWY)

2NDRY IMPRESSION TECHNIQUES

Boxing the impression

An impression is boxed to preserve the borders of the impression so that it will be accurately reproduced in the cast.

Methods for boxing

1- Wax method

2- Plaster and Pumice method

Beading wax for boxing

1- Wax Method

1-wax method

1-wax method Lower impression

2-Plaster and Pumice method

Plaster and pumice for boxing

2-Plaster and Pumice methodUpper impression

Advantages of boxing

1- The borders of the impression are preserved.

2- The thickness of the base can be controlled

3- It permits vibrating, prevents air bubbles and gives us denser cast.

4- Time for pouring the cast is conserved.

5- Materials are conserved.

**CHAPTER (4) OCCLUSION BLOCKS

USES Of The OCCLUSION BLOCKS

They help in 1- Supporting the lips and cheeks to restore the contour of

extraoral landmarks. 2-The orientation of the occlusal

plane.

3- Determining the vertical dimension.

4-Recording the centric and eccentric jaw

relations.

Cont. Uses of the Occlusion Blocks

6-Providing a matrix for arranging teeth.

5- Selecting the size and position of the artificial teeth by the aid of the following markings :

a- Midline b-High lip line c- Canine line

Cont. Trial Denture Bases

Types

Temporary

1- Shellac2- Autopolymerizing and light cured acrylic resin 3- Vacuum formed vinyl or polystyrene4- Baseplate wax5- Swaged tin

Permanent

1- metallic gold alloys cobalt chromium alloys

2- non-metallic heat cured acrylic resin

CHAPTER (5) RELIEF AND POST. PAL SEAL.

Relief areas

Hard Prominent areas

Maxillary Mandibular

Sensitive areas

Maxillary Mandibular

1-Median palatine raphae2-Torus palatinus {if present}

*Torus mandibularis {if present}*PROMINENT Genial tubercles.*PROMINENT Mylohiod ridge.

1-Incisive papilla2-Rugae area3-Flabby ridge4-Sharp bony spicules

1-Mental foramen in resorbed ridges 2-Flabby ridge3-Sharp bony spicules

Shape of Relief AreaIt is never well defined. It merges into the

surrounding fitting denture surface.

Depth of Relief:

It depends on the compressibility of the area to be relieved as wellas that of the surrounding areas.

Methods of Relief

I- Direct

1-Scrap the final

impression

2-Build tin foilon the master

cast

II- Automatic

I- Direct Relief 1- Scraping the Impression

I- Direct Relief 2- Build on the cast

II- Automatic Relief (Selective Pressure Impression Technique)

A- Scraping the compound selectively.

B- Secondary impression in Zn/O eugenol or plaster.

Value of Relief • Relief of sensitive areas increases the comfort of the patient.

• Relief of hard areas improves the denture stability, so itProlongs the duration of denture service by compensating for

denture settling and some ridge resorption .

• Compensate for polymerization shrinkage.

Position of the Post dam area

Posterior vibrating line

Functions of posterior palatal seal

1. Retention of maxillary denture.2. Prevents food accumulation under the

denture.3. Compensates for polymerization

shrinkage.4. Reduces patient’s discomfort.

Width of post dam area

Depth of Post Dam

Depends on the degree of compressibility of soft tissue in this area and on the extent of functional movement of the soft palate.

Methods of postdamming

1-Scraping method 2-Functional method

Methods of post damming

1-Scraping method


2- Functional method


2- Functional method

**CHAPTER(6) MANDIBULAR MOVEMENT.

A close up view of the joint

Basic mandibular movements

• Rotation in the lower compartment

• Translation in the upper compartment

They are usually classified according to the main direction of movement.

The starting position is the habitual intercuspal position, from this point the mandible can move into:

Possible Mandibular Movements

Lateral Movement Opening and Closing Movement

Forward & Backward Movement

WORKING

BALANCING

The inclination of the condylar pathTypes :A- Sagittal ( HORIZONTAL) condylar path angle

B- Lateral condylar path angle

No Translation

Translation

Border Positions of the Mandible

**CHAPTER (7) JAW RELATIONS

Jaw Relation“ It is any relation between the mandible and the maxilla.”

It is a three dimensional relation ( vertical, anteroposterior and lateral).

JAW RELATIONS

(1)VERTICAL RELATION. ( V.DO + V.D.R)

(2)ANTROPOSTERIOR RELATION. ( CENTRIC

RELATION + PROTRUSIV RECORD)

(3)LATERAL. ( LATERAL RECORDS)

Vertical dimensionTwo types are identified:

1- VDR “ The measurement, when the mandible is

in the physiologic rest position.”.

2- VDO“ The measurement , when the teeth or

occlusion rims are in contact.”

The interocclusal distance

“ It is the difference between the VDR and the VDO. In normal individuals its average value is 2-4 mm. It is also termed interocclusal clearance, gap &/or freeway space.”

Variables of the VDR

Short term variables

1- Head position2- Respiration 3- Stress

Long term variables

1- Loss of propiceptors decrease2- Age decrease

Sequalae of Improper Vertical Dimension of Occlusion

Jaw relation record (Maxillomandibular relationship record)“It is a registration of any positional

relationship of the mandible relative to the maxilla.”

Records have to be obtained before casts are mounted on the articulator using the ??????.

Importance of recording the jaw relation

1- Terminal hinge axis method

2- Chew in technique

3- Graphic tracing method

The resulting arrow represents the centric and eccentric relations

4- Check bite technique(Wax wafer method)

**CHAPTER (8) FACE BOW AND ARTICULATOR.

Types of Face Bows

Mandibular

“A device used to locate the transverse hinge or

the condylar axis.”

Maxillary

“A device used to record the relation between the

maxilla and the TMJ ( terminal hinge axis or condylar axis) and to

transfer this relation to the articulator.”

Maxillary Face Bow

Components:

GraduatedCondylar Rods

Tightening clamp

U Shaped Bow

Bite Fork

Universal Joint /Jack Clamp

Infraorbital Pointer

Graduations on the rod

Maxillary Face Bow Record

1- Bite fork is heated and inserted into the rim

.

Cont. Maxillary Face Bow Record

2-The condylar axis is then determined either accurately or arbitrary on the canthus tragus line.

11- 13 mm

Cont. Maxillary Face Bow Record

4- Universal joint once tightened , never opened.

Maxillary Face Bow Transfer

1- The slide bar clamp is unscrewd to remove assembly from the face.

Cont. Maxillary Face Bow Transfer

2- Assembly is now centralized on the articulator.

Mandibular Face Bow

Limited opening and closing allows the condylar rods to draw arcs. The rods are moved towards the center of the arcs, until they move in a point . The latter is called the still point and represents the condylar axis. The condyle in this position lies in the most retruded unstrained position in the glenoid fossa, so mandible and maxilla arein centric.

The articulator is a mechanical device which represents the temporomandibular joint and jaw members to which

maxillary and mandibular casts may be attached..

ARTICULATORS

Functions of Articulators

1- Helps in maintaining the desired jaw relationship of the cast during setting up of the teeth in the absence of the patient.

2- reproduces the mandibular movements.

Types Of Articulators

1- Simple Hinge Articulator

2- Mean (Average )Value or Fixed Condylar Path Articulator :

3- Adjustable Articulators : A- Semiadjustable condylar path articulators

B- Fully adjustable condylar path articulators

1- Simple hinge articulator

Eg. Gariot’s articulator

2- Mean (average) value or fixed condylar path articulator

Eg. Gysi and El Mahdy articulator

Mounting the upper cast by a face bow record

Bonwill triangle Method

3- Adjustable articulators

a- Semiadjustable condylar path

b- Fully adjustable condylar path

A- Semiadjustable articulator

Eg. Hanau model H articulator

A- Semiadjustable condylar path angulation articulator

Can accept the following records1-Face bow record to mount the upper cast2- Centric occluding relation record to mount the

lower cast 3- Protrusive record to adjust the articulator’s

horizontal condylar path inclination4- lateral condylar angulation adjusted according to

Hanau’s formula L=H/8+12

B- Fully adjustable articulator

Both horizontal and lateral inclinations are adjusted according to the records taken from patient mouth

1-Face bow record to mount the upper cast

2- centric occluding relation record to mount the lower cast

3-protrusive record to adjust horizontal condylar guidance

4-Right lateral record to adjust the left lateral condylar path angle

5- Left lateral record to adjust the right lateral condylar path angle

Articulators

Simple Hinge(plain)

Fixed Condylar Path Adjustable Condylar Path

Semi Adjustable Fully Adjustable

Movements Performed

Opening and

Closing

1) Opening and Closing.

2) Protrusive movement at fixed horizontal condylar path angle.(30°- 40°)

3) Lateral movement at fixed lateralcondylar path angle.(12°- 20°)


2) Protrusive according to patients horizontal condylar path.

3) Lateral movement as adjusted from hanau formula.

Hanau Formula: L=H/8 + 12.

L= Lateral Condyler Path Angle.H= Horizontal Condylar Path Angle.


2) Protrusive according to patient's horizontal condylar path.

3) Lateral movement according to patient's later condyler path.

Records Needed to Mount the Upper and Lower Casts.

Centric Occluding Relation.

1) Maxilary Faced Bow to mount upper cast.

2) Centric Occluding Relation to mount lower cast.

N.B; In some types upper cast can be mounted by Bonwell Triangle.



3) Protrusive record to adjust horizntal condylar path angle of the articulator.



3) Protrusive record to adjust horizntal condylar path angle of the articulator.

4) Right lateral record to adjust left lateral condylar path.

5) Left lateral record to adjust right lateral condylar path.

Examlpes Gariot's Articulator El Mahdy Articulator Hanau Model H Hanau Kinoscope

N.B;

-In most designs of this type, the upper member is movable while the lower member is stationary.

-Therefore the upper member moves backwards and upwards to simulates patients mandible in protrusion.

-This reverse nature of articualtors provides a firm base to facilitate arrangement of teeth.

Documents

REVISION (1) B.M.C