Record block or bite block OCCLUSION BLOCKS Record block or bite block

STEPS OF COMPLETE DENTURE CONSTRUCTION Clinical 1- Examination of the mouth.

1 . Examination and Diagnosis . 2 . Preliminary Impression . CLINICAL 1 . Examination and Diagnosis . 2 . Preliminary Impression . Stock Trays Alginate Impression Upper Lower

3 . Pouring the Impression . LABORATORY 3 . Pouring the Impression .

Clinical Laboratory 2- Preliminary impression making *Pouring of impression to obtain the study cast. *Construction of special (custom) trays

Clinical Laboratory 3 -Final impression. *Boxing and pouring of the final impression *Construction of recording bases and occlusion rims

Clinical 4-Recording of jaw relationships and selection of artificial teeth.

DEFINITION It is a combination of a base material, which accurately fits the cast (trial denture base ) and an arch shaped material occupying the space of the patient’s previous dentition (occlusion rim). It is therefore composed of a trial denture base & an occlusion rim trial denture base occlusion rim

USES Of The OCCLUSION BLOCKS They help in 1- Supporting the lips and cheeks to restore the contour of extraoral landmarks.

Cont. Uses of The Occlusion Blocks 2-The orientation of the occlusal plane.

Cont. Uses of the Occlusion Blocks 3- Determining the vertical dimension.

Cont. Uses of the Occlusion Blocks 4-Recording the centric and eccentric jaw relations.

Cont. Uses of the Occlusion Blocks 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

TRIAL DENTURE BASES (BASEPLATES) “Part of the occlusion block that rests on the supporting structures and carries the occlusion rim. “ Requirements: They should : 1- fit the cast accurately. 2-rigid and strong to withstand the biting force. 3-be dimensionally stable. 4-stable inside the patient’s mouth. 5 smooth and clean to avoid patient’s discomfort. 6-be of proper thickness (2mm on the palate & less on the alveolar crest). 7-be easily and quickly constructed. trial denture base

Cont. Trial Denture Bases Types Temporary 1- Shellac 2- Autopolymerizing and light cured acrylic resin 3- Vacuum formed vinyl or polystyrene 4- Baseplate wax 5- Swaged tin Permanent 1- metallic gold alloys cobalt chromium alloys 2- non-metallic heat cured acrylic resin

Cont. Trial Denture Bases Temporary trial denture bases 1- Shellac base plate : It is commonly used because of its cost. It is adapted on the cast either by dry or moist heat.

Cont. Trial Denture Bases Temporary trial denture bases 2- acrylic resin a-Autopolymerising It is either mixed and adapted on the cast or it is sprinkled on it. It offers rigidity, close adaptation and can withstand heat and pressure without deformation. b- Light cured resin :

Cont. Trial Denture Bases Temporary trial denture bases 3-Baseplate wax It is easily adapted and can be thinned to gain space to set the teeth. However, it lacks dimensional stability since it cannot withstand biting pressure and body temperature.

Cont. Trial Denture Bases Temporary trial denture bases 4- Swaged tin : Three layers of swaged tin adapted on a metal die of the master cast and cemented together by a thin film of hard wax. It is accurate, dimensionally stable at mouth temperature and provides uniform thickness of the final denture.

Cont. Trial Denture Bases Temporary trial denture bases 5- Vacuum formed vinyl : Preformed sheets adapted by vacuum. It provides a fast, rigid and accurate record bases. However, it needs expensive equipments and is difficult to trim.

Cont. Trial Denture Bases Permanent trial denture bases 1- Heat cured acrylic resin

Cont. Trial Denture Bases Permanent trial denture bases 2-Metal (gold, cobalt chromium and chromium nickel alloys)

OCCLUSION RIM “ They are occluding surfaces fabricated on temporary or final denture bases to record the maxillomandibular relation and to arrange teeth. They simulate the space occupied by the natural teeth and the related structures.” Material of construction : 1- Wax : most commonly used. 2- Modeling plastic 3- Plaster and pumice Wax occlusion rim

Method of construction of wax rims Cont. Occlusion Rim Method of construction of wax rims 1- Ready made rims: by a device called occlusion rim former . 2- Freehand molded rims: wax rolled and shaped to the arch form .