3Prosthodontics (Prosthetic Dentistry) ProstheticsThe art and science of supplying artificialreplacement for missing parts of the human body.ProsthesisAn artificial replacement of an absent part of the human body.Prosthodontics (Prosthetic Dentistry)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.
4Components of complete denture 211- Denture base2- Artificial teeth
8Steps of Complete Denture Construction ClinicalLaboratory1. Examination & Diagnosis2. Primary impressionStudy castSpecial tray3. Final impressionBoxing and pouring master castOcclusion blocks4a. Jaw relation registration4b. Selection of artificial teethMounting on articulatorSetting of artificial teeth and waxing up5. Try inProcessing6. Insertion7. Post insertion care
9Objectives of complete denture 1-Restoration of the function of mastication to restore the normal digestive process2- Appearance (esthetics) restoring the normal appearance of the face especially the lower third of the face.
103- Correction of speech defects ►Loss of teeth (especially anteriors) Speech Defects►The artificial teeth should be placed in a positionpreviously occupied by the natural teeth.4- Preservation of the remaining tissues
14Anatomical Landmarks In Relation To Complete Denture : Extra Oral LandmarksInter pupillary lineAla Tragus LineNaso – Labial sulcusModulusLabiomental sulcus
15Anterior Occlusal Plane Determination Inter pupillary lineAnterior Occlusal Plane DeterminationAla Tragus linePosterior Occlusal Plane DeterminationNaso – Labial sulcusBecomes deeper with age and with loss of teethModulusBecome Flat With The Loss Of TeethLabiomental sulcusClasses of jaw relations
16Intra Oral Landmarks Incisive Papilla Denture Bearing areas / Upper 1 . The incisive papilla is a thick part of the mucous membrane coveringthe 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 foramento supply the anterior 2 / 3 of the palate.4 . In some cases due to the excessive bone resorption, the papilla may lieon the crest of the ridge.5 . The incisive papilla should be relieved to avoid pressure on the incisivenerves and vessels.CAUSING BURNING SENSATION IN THE ANT. 2/3 OF PALATE
17Denture Bearing areas / Upper Palatine RugaeRaugae Area1 . It is an irregularly shaped elevations of soft tissue extendinglaterally from the midline in the anterior part of the hard palate.2 . It serves as one of stress bearing areas in the palate .
18Denture Bearing areas / Upper Median Palatine RaphaeMedian Palatine Raphae1 . The midline of the hard palate is covered by a thin layer ofmucoperiostium , 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 .
19Denture Bearing areas / Upper Fovia PalatinaFovia Palatina1 . It helps in the determination of the posterior borderof the upper denture.2 . The posterior border of the upper denture should be 2 mmposterior to the fovea Palatina .
20To Continue ( Bearing Areas) Residual Alveolar RidgeResidual Alveolar Ridge1 . 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 .
21To Continue ( Bearing Areas) Buttress Part Of BoneButtress Part Of Bone1 . 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).
22To Continue ( Bearing Areas) TuberosityTuberosity1 . It is important for retention and support of the upper dentureagainst lateral movement.2 . The denture should cover it , because it is one of stress bearingareas in the upper jaw .
23To Continue ( Bearing Areas) Immovable Part of Soft PalateImmovable Part of Soft Palate1 . The immovable part lies adjacent to the hard palate and themovable part lies more posterior.2 . The posterior edge of the upper denture should end at the junctionof these two parts .
24Denture Limiting Structures (Upper) Labial FrenumLabial FrenumIt must be relieved in the denture by making a V-shape notchin the labial flange opposite to its position .
25Denture Limiting Structures (Upper) Labial VestibuleLabial Vestibule1 . It Is the reflection of the mucosa of the lip to the mucosa of thealveolar process in the labial vestibule.2 . The denture in this area is in relation to the orbicularis oris and thesuperior incisive muscles .3 . These muscles limit the thickness and the length of the labial flangeof the denture.
26Denture Limiting Structures (Upper) Buccal FrenumBuccal Frenum1 . 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 tofacilitate its functional movements.
27Denture Limiting Structures (Upper) Buccal VestibuleBuccal Vestibule1 . 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.
28Denture Limiting Structures (Upper) Hamular NotchHamular Notch1 . It is one of the important landmarks for determination of the posteriorlimit of the upper denture .2 . A straight line from hamular notch on one side to the other on the otherside determines the posterior limit of the upper denture
29Denture Limiting Structures (Upper) 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.
30Denture Bearing and Limiting Structures (Lower) Retro Molar BadRetro Molar pad1 . It is a pear shaped area of mucous membrane at the posterior end of themandibular ridge and anterior to the pterygomandibular raphae .2 . It consists of mucous glands , temporal tendon , fibers of thebuccinators and superior constrictor muscle .3 . Lower denture should cover this area for retention and to coverthe buccal shelf of bone.
31Denture Bearing and Limiting Structures (Lower) Buccal Shelf Of BoneBuccal ShelfOf Bone1 . The area that lies between the crest of the residual ridge andthe external oblique ridge.2 . It is the primary stress bearing area in the lower arch .3 . It forms good support for the lower denture .
32Denture Bearing and Limiting Structures (Lower) Buccal VestibuleBuccal Vestibule1 . The denture in this area is related to the buccinator muscle .2 . Its contraction does not displace the lower denture so flanges ofthe lower denture must extend in the buccal vestibule.
33Denture Bearing and Limiting Structures (Lower) Buccal FrenumBuccal Frenum1 . It is a fold of mucous membrane in the premolar area, movement ofthe lip and the cheek move the frenum .2 . A notch is made in the lower denture to accommodate the frenum.
35Denture Bearing and Limiting Structures (Lower) Residual RidgeResidual Ridge
36Denture Bearing and Limiting Structures (Lower) Lingual PouchLingual PouchMore posteriorly the lingual flanges are related to the lingual pouch withits boundaries which are :Posteriorly : The palatoglosssus muscle .Anteriorly : The Mylohyoid muscle.Medially : The tongue .Laterally : The medial aspect of the mandible.
37Denture Bearing and Limiting Structures (Lower) Sublingual salivarygland areaSublingual salivarygland areaThe lingual flanges of the lower denture should not extend in this areabecause with excessive resorption of the mandible the gland maybulge superiorly above the body of the mandible.
38Denture Bearing and Limiting Structures (Lower) Lingual FrenumLingual Frenum1 . More anteriorly a fold of mucous membrane attach the mucosa of thetongue to mucosa of the floor of the mouth2 . It moves with the movement of the tongue so a notch is made toaccommodate the frenum.
41The body and handle are designed to suit different mouths 1-Dentulous mouth cases.2-Edentulous mouth cases3-Partially edentulous mouth cases.
42Types of special trays1- 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
43Comparison between shellac and acrylic resin custom trays Shellac base plate special trayLow strength.2. Easily distorted by load and temperature.3. Improper adaptation to the cast4. Easily constructedSelf-cured acrylicresin special trayHigher strength and rigidity.Not distorted by temperature.Well adapted4. Easily constructed
47ImpressionImpression is a negative likeness or copy. Cast is a positive copy
48Preliminary (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.
49Final (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. “
502NDRY IMPRESSION TECHNIQUES MINIMAL PRESSURE( MUCOSTATIC)FUNCTIONAL PRESSURE (MUCOCOMPRESSIVE)SELECTIVE PRESSURE(2) PHILOSOPHYALL 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) TRAYPERFORATED + 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) PRESSUREFINGER PRESSUREPATIENTS BITING FORCE.FINGER PRESSURE.(5) IMPRESSION MATERIALPLASTER, FLOWY MATERIAL.ZnO/E , HEAVY MATERIALIMPRESSION COMPOUND (HEAVY)+ PLASTER OR ZnO/E(FLOWY)
51Boxing the impressionAn impression is boxed to preserve the borders of the impression so that it will be accurately reproduced in the cast.
52Methods for boxing1- Wax method 2- Plaster and Pumice method
58Advantages of boxing1- 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.
60USES Of The OCCLUSION BLOCKS They help in1- 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.
61Cont. Uses of the Occlusion Blocks 5- Selecting the size and position of the artificial teeth by the aid of the following markings :a- Midlineb-High lip linec- Canine line6-Providing a matrix for arranging teeth.
65Shape 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.
66Methods of ReliefI- Direct1-Scrap the finalimpression2-Build tin foilon the mastercastII- Automatic
69II- Automatic Relief (Selective Pressure Impression Technique) B- Secondary impression in Zn/O eugenol or plaster.A- Scraping the compoundselectively.
70Value of ReliefRelief 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.
71Position of the Post dam area Posterior vibratingline
72Functions of posterior palatal seal Retention of maxillary denture.Prevents food accumulation under the denture.Compensates for polymerization shrinkage.Reduces patient’s discomfort.
82Basic mandibular movements Rotationin the lower compartmentTranslationin the upper compartment
83Possible Mandibular Movements 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:Opening and Closing MovementLateral MovementForward & Backward Movement
94Vertical dimension Two 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.”
95The 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.”
96Short term variables 1- Head position 2- Respiration 3- Stress Variables of the VDRShort term variables 1- Head position 2- Respiration 3- StressLong term variables 1- Loss of propiceptors decrease 2- Age decrease
97Sequalae of Improper Vertical Dimension of Occlusion
98Jaw 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 ??????.
106“A device used to locate the transverse hinge or the condylar axis.” Types of Face BowsMandibular“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.”
107Maxillary Face Bow Components: Graduations on the rod Graduated Condylar RodsInfraorbital PointerBite ForkTightening clampUniversal Joint /Jack ClampU Shaped Bow
108Maxillary Face Bow Record 1- Bite fork is heated and inserted into the rim .
109Cont. Maxillary Face Bow Record mm2-The condylar axis is then determined either accurately or arbitrary on the canthus tragus line.
110Cont. Maxillary Face Bow Record 4- Universal joint once tightened , never opened.
111Maxillary Face Bow Transfer 1- The slide bar clamp is unscrewd to remove assemblyfrom the face.
112Cont. Maxillary Face Bow Transfer 2- Assembly is now centralized on the articulator.
113Mandibular Face BowLimited opening and closing allows the condylar rods to draw arcs.The rods are moved towards the center of the arcs, until they movein a point . The latter is called the still point and represents thecondylar axis. The condyle in this position lies in the most retrudedunstrained position in the glenoid fossa, so mandible and maxilla arein centric.
114ARTICULATORSThe articulator is a mechanical device which represents the temporomandibular joint and jaw members to which maxillary and mandibular casts may be attached..
115Functions 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 reproduces the mandibular movements.
116Types Of Articulators Simple Hinge Articulator Mean (Average )Value or Fixed Condylar Path Articulator : Adjustable Articulators : A- Semiadjustable condylar path articulators B- Fully adjustable condylar path articulators
1171- Simple hinge articulator Eg. Gariot’s articulator
1182- Mean (average) value or fixed condylar path articulator Eg. Gysi and El Mahdy articulator
122A- Semiadjustable articulator Eg. Hanau model H articulator
123A- 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 cast3- Protrusive record to adjust the articulator’s horizontal condylar path inclination4- lateral condylar angulation adjusted according to Hanau’s formula L=H/8+12
124B- Fully adjustable articulator Both horizontal and lateral inclinations are adjusted according to the records taken from patient mouth1-Face bow record to mount the upper cast2- centric occluding relation record to mount the lower cast3-protrusive record to adjust horizontal condylar guidance4-Right lateral record to adjust the left lateral condylar path angle5- Left lateral record to adjust the right lateral condylar path angle
125Adjustable Condylar Path ArticulatorsSimple Hinge (plain)Fixed Condylar PathAdjustable Condylar PathSemi AdjustableFully AdjustableMovements PerformedOpening and Closing1) Opening and Closing. 2) Protrusive movement at fixed horizontal condylar path angle.(30°- 40°) 3) Lateral movement at fixed lateralcondylar path angle.(12°- 20°)1) Opening and Closing. 2) Protrusive according to patients horizontal condylar path. 3) Lateral movement as adjusted from hanau formula. Hanau Formula: L=H/ L= Lateral Condyler Path Angle. H= Horizontal Condylar Path Angle.1) Opening and Closing. 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.1) Maxilary Faced Bow to mount upper cast. 2) Centric Occluding Relation to mount lower cast. 3) Protrusive record to adjust horizntal condylar path angle of the articulator.1) Maxilary Faced Bow to mount upper cast. 2) Centric Occluding Relation to mount lower cast. 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.ExamlpesGariot's ArticulatorEl Mahdy ArticulatorHanau Model HHanau KinoscopeN.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.