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Success of complete denture
1 .Diagnosis and Examination .2 .Taking Impression: Primary impression .
Secondary impression.3 .Master cast. 4 .Record block:
Record base. Occlusal rim.
Success of complete denture depend on success of every clinical and laboratory steps:
5.Jaw relation.
6.Mounting.
7.Setting of teeth.
8.Waxing up.
9.Try in.
10.Denture insertion.
Diagnosis and Examination
• Success of complete denture firstly depend on a good diagnosis especially intra oral diagnosis.
• The dentist should make a diagnosis for the following:
1)Arch form
• It may be square,ovoid or tapered.• Each shape of this has a role in retention and stability of denture.
• Square arch form more retention,stability& also ►support due to increase surface area coverage.
• Oval & tapered arch form less retention, stability so ►the dentist should think about other means to increase retention.
2)Vault form
• It may be V-shape or U-shape or flat shape vault.
• U-shape vault good retention & stability.►• V-shape vault good stability but less retentive ►and this can improved by making good peripheral seal.
• Flat shape vault good retention but less ►stable and this can improved by making good adaptation.
3)Residual ridge contour
• It may be rounded,knife edge,flat resorped, flappy fibrous ridge.
• Every type needs special impression material & technique.
• Rounded firm ridge taking impression with alginate.►• Knife edge ridge taking impression with rubber base ►material.
• Flat shape ridge taking impression with compound.►• Flappy fibrous ridge need special impression ►technique as selective pressure technique.
4)maxillary tuberosity
• It aids in support&retention of the upper denture as complete coverage give wide area under denture which help in support and also give good seal which help in retention.
• It is very important to know the size&form to know how to deal with.
5)Retro molar area
• It is called the postdam of lower denture so it should cover to help in retention of lower denture.
6)Maxillary&Mandibular undercuts
• It needs a special impression material as alginate or rubber base.
7)Tori
• It may found in the palate (torus palatinus) or in the mandible (torus mandibularies)
• The tori if present at the patient mouth it may cause interference with denture making as it may cause rocking of the denture and may also lead to ulceration to the tissue and pain to the patient.
• So if it is small make relief.► if it is large surgical removal.►• Torus palatinus if present in midline of the palate and not relieved it lead to rocking of the denture and may also lead to midline fracture of upper denture.
8) Tongue size & position
• It may be one of the interference factors in making denture and may affect the stability of the lower denture.
• In edentulous patient for long time tongue take large space and adapt it self to move freely so the dentist should tell the patient to be patient as the tongue will move the lower denture.
9)Saliva
• Selection of suitable impression material.• Detection of the amount of base plate retention that help in recording of accurate vertical and horizontal relation.
• Great value in complete denture retention.
The amount and consistency of saliva play an important role in making a denture as it help in:
10)Mucosa
• If it is flabby the dentist should follow a special impression technique as selective pressure technique.
11)Depth of the sulcus
• Shallow sulcus needs special impression ► technique with adequate peripheral seal to increase retention & stability.
"Complete denture impression"
is one of the important steps in denture construction as all steps depend on its exactness, it is a negative registeration of the entire denture bearing and border seal area present in the edentulous mouth .
Definition:
Types:
• made in stock tray for making ►a study cast on which a special tray is constructed.
Primary impression:
Secondary impression:
• made in special tray for making a ► master cast on which the denture is constructed.
Requirements:
• Impression must cover all maximum allowable possible denture bearing surface to assure wide distribution of stress and less pressure per unit area .
• Impression must form the denture borders.• Impression must record the fine details of the surface of soft tissue to be covered by the denture.
• Impression materials should be selected according the patient's mouth.
Objectives of impression:
Complete denture impression should provide :
Retention""
• It is the resistance to vertical force away from the soft tissue.• It depends on peripheral seal.► ►post dam in upper arch. And close adaptation to undistorted ► mucosa
"Support"
• It is the resistance to vertical force towards the basal seat.
• Maximum coverage provide distribution of load over wide area the force per unit area ►is reduced help in preservation of the ►supporting structures.
"Stability"
• It is the resistance to horizontal movement.
Denture stability depends on:
• The size and form of the basal ridge.(loss of vertical high of the ridge and increase flappy movable tissue decrease stability.)►
• The quality of the final impression impression.• The form of the polished surface.• The proper location and the arrangement of the artificial teeth.
• Denture stability is very important to preservation ►denture supporting structures.
"Tissue preservation"
• Preservation of the remaining residual ridges is the main objectives.
• Keep in mind that : pressure in the impression technique results to pressure in the denture and results to soft tissue damage and bone resorption.
"Esthetics"
Denture should : ►Restore facial contour.
►provide lip suuport .
Custom tray
Custom tray
• The custom tray (commonly made by acrylic resins) should be fabricated 24 hours before the impression procedure.
• Should be well adapted on the primary cast.• Free of voids and nodules on the surface facing the tissues.
CONSIDERATION FACTORS FOR FABRICATION OF THE CUSTOM IMPRESSION TRAY :
Objectives of master cast
• Free of voids or nodules. • The surface of cast should be hard and dense. • The side walls of a cast should be vertical.• The base of cast should not be less than 10mm.• The base of the cast is parallel to the edentulous ridge.
• The contour of the anterior border of the base of maxillary cast is pointed at the midline and curved from canine to canine in the mandibular cast.
• The peripheral roll should be not deeper than 3-4 mm and the edges of the cat extending out from this 3-4 mm wide.
• The land area of 2-3 mm should be maintained around the entire cast.
Record Blocks
Record Blocks
• Well adapted to the final cast.• Stable both on the cast and in the mouth.• Rigid.• Free of voids or projections on the surface that contacts the oral mucosa.
• Easily removed fron the cast.• Smooth and rounded.• The border length and thickness is approxamitely the same as the final denture base.
• Fabricated from materials that are dimensionally stable.
Criteria for recording bases:
Criteria for occlusal rim:
• It should be well attatched to the underlying base.• It must be placed directly over the ridge.• It should follow the form of the arch.• It should have a smooth surface.• It must be constructed from a material that easy to manage.
• Its width must permit occlusion of the upper and lower occlusion rims.
Jaw Relation
Jaw Relation
Jaw relation can be classified into 3 groups :
means the static &functional relation of the mandible to maxilla.
Orientation relation is the references in the cranium ,when the mandible in the most posterior position it can be rotated in sagittal plane around transverse axis plassing through the condyles,this axis can be located by :
Kinematic facebow. Arbitrary facebow.
Vertical relation
• The vertical space between upper and lower jaw or the amount of jaw separation allowable for denture
• There are 3 types :
VD at Rest VD of occlusion
VD of other position
The effect of excessive occlusal VD• Discomfortthe patient has acqired over a period of many years cortical pattern which control automatically &unconsciously certain mandibular movement• Traumathe premature striking of the teeth causes constant truma on the tissue • Clicking of teethpremature contact of teeth during speech or eating will produce clicking • Appearanceover-oppeninng may result in an elongation of the face
The effect of inadeqate occlusal VD
• Cheek biting
• TMJ troubles
• Inadeqate eating & chewing
• Ms fatigue
• Angular chelitis
Horizotal relation
• The significance of the centric is the irregular loss of teeth has often shunted the mandible into aslight protrusive or lateral position .
• The muscles ,the ligaments, the bones, the teeth &all structures grow into what may be named { A muscle center}.
How to record centric relation ?• THere are 2 concepts :• Minimal pressure technique ,so;tissue not displaced while recording the opposing teeth touch at their 1st contact ,so will not stimulate pt. to clench.
• With heavy pressure technique ,so tissue displaced while recording So produce the same displacement when heavy pressure where applied on the denture .
• The choice bet.2 methods depends on the concept of occlusion selected .
• Recording horizontal jaw relation ;• Inter occlusal or cheeck bite method .• Graphical or Gothic arch tracing.
Mounting
Mounting
• A laboratory procedure of attaching the maxillary and the mandibular cast to an articulator or similar instrument.
Definition
Articulators
• A mechanical instrument that represents the tempromandibular joint and jaws which maxillary and mandibular casts may be attatched to stimulate some or all mandibular movement.
Requirements• The articulator must accurately maintain the correct horizontal and vertical relationship of the patient.
• The casts must be easily removed and attatched to the articulator without losing their correct relationship.
• Should have an incisal guide pin with a positive stop to preserve the patient vertical dimension.
• Should be able to open and close in a hing like fashion.
• The articulator should accept a facebow transfer.• The condylar guidance should allow right,left lateral protrusive movement.
• The incisal guidance should be adjustable.
To achieve balanced occlusion we must arrange teeth in anatomical articulation...
• At any occlusal relationship maximum number of teeth are in contact and therefore the masticatory pressure is distributed over the suppoting tissues.
Advantages of anatomical articulation:
Balanced occlusion
Stability
• Maximum number of teeth contact no tilting of the denture occur
Reduced truma
• as the masticatory pressure will be distributed as evently as possible and thus reduce damage to the supporting tissues.
Efficiency• Griding and cutting of food stuff are possible because lateral and protrusive movement can be made to maintain balanced articulation also chewing time and masticatory cycle will be reduced pressure on the supporting tissues and bone resorption will be reduced.
Functional movement
• Patients will become accustomed to dentures which anatomically set up as it allow a continuation of normal masticatory movement.
Time saving
• As balanced articulation have been obtained by the technician in the laboratory only minor spot grinding to be done in the clinic and thus save time.
Setting of teethGeneral consideration for arrangement of teeth
For anterior teeth
• We must take in consideration esthetic&phonetics.
For posterior teeth
Anatomic factors of occlusion
• Condylar guidance.
• Incisal guidance.
• Cusp height.
• Compensating curves.
• Orientation of the occlusal plane.
(Law of balanced articulation)
WAXING-UP OF COMPLETE DENTURES
• Waxing-up: is the process of waxing and carving of the
wax to the shape and contour of a trial denture into the
desired form.
Definition
Importance
• Stability of the dentures
• Influences its retentive quality.
• Influences the aesthetic of the denture.
• Support the cheeks, lips and tongue
The form of the polished surfaces and the proper location of the artificial teeth play a major role in:
Criteria for waxing up
• The wax periphery must be – extended to the maximum depth. – Fully rounded – Highly polished.
• The labial waxing may be thickened in order to restore lost facial contour.
• The buccal surface should face downwards and outwards.• Festooning and cusped eminence should be provided.• Gingival crests should be trimmed exactly to the finished line. No deep grooves should be done.
• Stippling of the facial surface.• The palatal surface will face inwards and downwards. • The palate should have an even thickness of 2.5 mm.
Upper denture
Lower denture• The labial surface concave. • The peripheries
– Fully rounded – Highly polished.
• In the premolar region the buccal surface flat and thin. • In the molar region
– The wax thickened and widened – Face outwards and upwards.
• The lingual surface must face inwards and upwards (concave). The concavity does not extend under the teeth (in the middle of the flange) so that the tongue does not raise the denture.
• The wax should be extended to cover the maximum area possible in the retromolar region.
The lingual flange should not be bulky
Try-in of the trial denture
• Preliminary insertion of a complete denture wax-up trial denture to determine the fit, esthetics, maxillomandibular relations
• It is the last opportunity to evaluate many of the pervious steps already accomplished
• It is also offers an excellent opportunity for patient's acceptance of the finished prosthesis
Definition
Objectives of try in• Check maxillomandibulor relationship – Centric occlusion – Centric relation – Acceptance of the vertical dimension of the occlusion
• Determine if the position of the teeth and the contours of the denture bases are compatible with the surrounding oral enviroment
• To verify tooth selection and arrangement for proper esthetics and phonetics
• To make additional interocclsual maxillomandibulor records if needed for future adjustment of the articulator
Denture Insertion
• physical needs required for performing adequate function without causing truma to the supporting structures.
• physiological needs by allowing the proper support needed by the muscles to provide proper esthetic.
• psychologic needs by providing proper function and esthetic.
The appointment of denture insertion is the moment awaited by the patient.
The finished denture should fulfill
Objectives of denture insertion step
• To check retention,stability,accurancy of jaw relation.
• To instruct the patient how to use his denture. • To advice the patient on the proper care of his dentures and supporting tissues.
• To advice the patient on the limitations to be expected of his denture.
Patient guide to use the denture
Patient guide to use the denture
• Dental patients with complete dentures need to take care of their oral health, just as if they still had their natural teeth.
• The most important thing these dentures are trying to achieve is restoring the patient’s lifestyle.
• Dentures ideally remain unchanged; yet, your mouth is constantly changing. If you fail to wear your dentures for a while, for your own reasons, you will find it doesn’t fit any more. As we grow old, the oral cavity tends to shrink and the gum line to withdraw.
• Many patients with dentures consider that they no longer need to visit their dentist, since they have no more natural teeth to take care of. Even if you no longer have your natural teeth, your visits to the dentist must not become history. You need to maintain a healthy oral cavity and keep your dentures in good shape. Even at a more advanced age, patients can experience misalignments of their dental arches. It is highly important that you prevent and treat denture irritations and infections. It is better to ask your doctor how often you need to come back for a dental check-up.
• Dentures are meant to improve the quality of life in patient who lost their natural teeth, not to cause further inconvenience.
• When not in your mouth, your dentures should be kept in a glass of water or other special liquid. Do not place them in hot water and do not let them dry! You need to clean them on a daily basis, using a toothbrush. Never use rough detergents to clean your dentures.
• Don’t try to fix your broken dentures at home. As strange as it may seem, many patients try to glue their broken dentures with chemical adhesives they buy from the supermarket and try to adjust them using a nail file or similar to avoid accidents, don’t do this at home! Ask your dentist about any necessary repair.
