________ is a negative registration of the entire denture bearing, stabilizing, and border seal areas present in the edentulous mouth.
Objectives of Final Impression
- Preservation: of soft and hard oral tissues; by ideal stress distribution.
- Support: by maximum coverage and extension within the physiologic limit of the soft tissue.
- Stability: by close adaptation to the underlying mucosa
- Retention: By providing physiologic atmospheric pressure
- Esthetics: By proper lip support with flange thickens
Criteria of Ideal Impression
- cover the maximum possible area without interfering with normal muscle movements.
- record the fine details of the tissues.
- even thickness with well rounded flanges
- free of voids
- free from pressure area (The tray flange should not show through the impression)
- The extent of the impression should cover the retro-molar pad of the mandible and the vibrating line of the maxilla.
Final Impression Materials
- Zinc Oxide and Eugenol Imp
- Silicone Impression.
- Wax Impression.
- Tissue Conditioning Imp.
Selective Pressure Impression Technique
Record selected area (stress bearing areas) in a displaced (functional) position and relief other area (sensitive and sharp areas) from pressure.
Sequence of making Final Impression
- Establish the contour of the denture borders by border molding the custom tray using a modeling compound material
- Final wash impression by using a high flow final impression material.
Instruct the patient to leave out their old dentures _______ before final impression appointment.
at least 24 hours
the vibrating line or Ah line is at the junction between _______.
the movable and immovable parts of the soft palate
Border Molding Cut-Back
scrape away a thin layer of compound at the edge of the border molding
Compared to a dentate person, the bite force of a complete denture patient is _______; the masticatory efficiency is _______; the proprioception is ________.
- approximately 25-40%
- approximately 17-24%
- approximately 50%
The simultaneous contact of the maxillary and mandibular teeth in the right and left and in the anterior and posterior occlusal areas when the jaws either in centric, lateral, or protrusive positions.
True Hinge Axis
Is difficult to determine especially in edentulous patients and requires a Mandibular face bow.
Arbitrary Hinge Axis
- •Is an estimate axis location, like using Gysi’s point which is on the line between the upper border of the Ext. Aud. Meatus and the outer canthus of the eye, 13 mm ant. to the meatus
- •Earbows use the external auditory meatus reference point as arbitary Hinge axis location.
The height of occlusal plane of maxillary rim should be ___________.
1-2 mm below the lowest portion of the relaxed upper lip (low lip line)
The _________ is the line just contact with the
- lower border of the upper lip when it is raised as high as possible unaided, as in smiling or laughing and it indicates _________.
- high lip line
- the length of the teeth needed
The corner lines (canine lines) mark ___________ and determine ________ and ________.
- the corners of the mouth when the lips are relaxed
- the position of the maxillary canines cusp tips
- the width of six anterior teeth
Methods for Recording Vertical Dimension
- • Facial measurements
- • Tactile Sense- where patient feels most comfortable
- • Phonetics- Repeat the letter “mmmm” and relax then confirm with the “S” sound (closest speaking space).
- • Facial Expression- recognize the patient’s relaxed facial expression when the jaws are at rest.
- • Measurement of Biting force
- VDO = VDR - Free way space (2-4mm)
Anterior teeth are primarily selected to satisfy _______ requirements; Posterior teeth are primarily selected to satisfy _______.
- masticatory requirements / occlusion
Frush and Fisher integrated the selection of teeth into an esthetic system governed by the, sex, personality and age of the patient (S.P.A.)
Sequence of Anterior Tooth Selection
Size (width then length), Mold form, Shade
The lip support is ________ except that in severe ridge resorption _________ play an important role in lip support in addition.
- primarily from anterior teeth position (Wax Rim)
- the labial flange thickness
Smile Line is formed by _________ during smiling. Ideally the incisal edges of ________ are in harmony with this line, otherwise it will be a reverse smile line (non-harmonious).
- the lower lip
- the maxillary anterior teeth, cusp tips of canines and premolars
The vertical overbite is 0 mm in ________ and up to 2 mm in ________.
- Monoplane Occlusion
- Balanced Occlusion
Posterior Tooth Forms
- Anatomic, Cusped teeth 33 degree teeth first introduced by Dr. Alfred Gysi 1913 (True-Bite teeth)
- Semi-Anatomic (10,20 degree)
- Non- Anatomic, 0-degree, Monoplane teeth first introduced by Sears 1928 (Channel teeth)
bilateral balance limits tipping of the dentures during _______, and can be achieved by ________.
- parafunctional habits
- 1- Cusp teeth (cross tooth/cross arch) Balance
- 2- Monoplane teeth with balancing ramps
Balance in Monoplane teeth Minimize vertical overlap within the dictates of esthetics and phonetics
Monoplane Occlusion (Neutrocentric Concept)
- 1. neutralization of inclines
- 2. centralization of occlusal forces acting on the denture foundation.
- - This concept of occlusion assumes that the plane of occlusion should be parallel to the denture foundation area and not dictated by condylar inclination.
- - There is no curve of Wilson or Curve of Spee (compensating curve) incorporated into the set up.
- 3. no vertical overlap of the anterior teeth.
- 4. “the patient will become a chopper, not a chewer or a grinder.”
Five facttors involved in arrangement of teeth in monoplane occlusion
- 1. position: central position
- 2. proportion: reduction of 40% in size
- 3. pitch: the occlusal plane is parallel to the ridge.
- 4. form: cusps are flat without affecting chewing efficiency
- 5. Number: eliminate second molar in cases of setting on inclined plane
- a special teeth arrangement in which the lingual cusp tips should be in contact with the central fossae of the opposing mandibular teeth.
- The cuspal inclines of the mandibular teeth are flat or relatively flat (SemiAnatomic), resulting in potentially less lateral forces and displacement during function.
- only the lingual cusps of the maxillary posterior teeth are in contact in centric and eccentric movements
Indications of using Lingualized Occlusion
- High esthetic demands
- Severe mandibular ridge atrophy
- Displaceable supporting tissues
- Previous successful denture with Lingualized Occlusion
Advantages of using Lingualized Occlusion
- Good esthetics
- Freedom of teeth (no interlocking)
- Potential for bilateral balance
- Centralizes vertical forces
- Minimizes tipping forces
- Facilitates bolus penetration (mortar and pestle effect)
- Five Factors Affecting Occlusal Balance
- 1.Condylar Inclination (Guidance)
- 2.Incisal Guidance
- 3.Occlusal Plane Inclination
- 4.Compensating Curve
- 5.Cuspal Inclination
Inter-relationship of Hanau's Quint may be described by _______ to maintain a balanced occlusion.
- Theilman’s Formula
- C= Condylar Inclination x Incisal Guidance / (Occ Plane inclination x Cuspal Inclination x Comp Curve)
Of Hanau’s Quint, the patient presents ________, ________ cannot be altered substantially since functional requirements dictate its position and orientation, _______ can be controlled by the dentist.
- Condylar Inclination
- Occlusal Plane
- Incisal Guidance, Compensating Curve, and Cuspal Inclination
Within the confines of esthetics and phonetics, minimize _______ in Complete Dentures to minimize tipping forces.
Is “Balance” Necessary?
- Bolus in -> Balance out
- No patient preference
- Balanced slightly more efficient
- Should be used in patients with para-functional habits.
- cuspless teeth primarily for ease of use
- can’t prove balanced occlusion is necessary
- Investigators have not shown one type of denture occlusion to be: Superior in function, Safer to oral structures, or More acceptable to patients.
______ may be the single most significant factor in the successful manipulation of complete dentures under function.
________ are essential factors for patients acceptance to their denture.
Tongue function and denture wearing experience
The border of _______ should be 2mm short of the vestibule. This to provide a space for ________.
- the custom tray
- the border molding and impression material
The final impression wash is made using _____ impression material to record the tissue fine details, while the border molding is made to record _______ both in width and length.
- the denture's limiting structure (eg. Vestibule)
The sequence of border molding is:
- heat the compound on bunsen burner
- apply it on the tray
- tempering it in 130 F water bath
- mold it in patient's mouth
The proper sequence of jaw relation visit is:
- check record base
- check and adjust wax rim
- face bow
- CR and VDO