Lecture 1 - Intro and Surveying Flashcards
Definition of a partial denture
prosthesis that replaces one or more teeth, but not all. It is supported by the teeth and/or mucosa. May be fixed (i.e. bridge) or removable
Definition of a removable partial denture (RPD)
partial denture that can be removed and replaced in the mouth by the patient
Definition of an interim denture. What is its purpose?
Provisional; temporary denture. Esthetics, mastication, occlusal support and convenience. Also to condition the patient to accept the final prosthesis.
Definition of Retention
Resistance to removal from the tissues or teeth
Definition of stability
Resistance to movement in a horizontal direction
Definition of support
Resistance to movement towards the tissues or teeth
Definition of abutment
Tooth that supports a partial denture
Definition of a retainer
component of a partial denture that provides both retention and support for the partial denture
4 Objectives of an RPD design
- preserve remaining teeth and supporting structures 2. restore esthetics and phonetics 3. restore and/or improve mastication 4. restore health, comfort and quality of life
What do we call a non-treatment alternative to an RPD?
SDA - shortened dental arch
What are the minimum requirements for acceptable function in a SDA (2 options)
- symmetric loss - requires anterior teeth AND 4 occlusal units 2. asymmetric loss - requires 6 occlusal units
What are occlusal units?
opposing premolar = 1 unit opposing molar = 2 units
What are 8 indications for RPD’s?
- lengthy edentulous span (too long for a fixed prosthesis) 2. no posterior abutment for a fixed prosthesis 3. excessive alveolar bone loss 4. poor prognosis for complete dentures due to residual ridge morphology 5. reduced periodontal support for abutments 6. cross-arch stabilizaiton 7. need for immediate replacement of extracted teeth 8. cost/patient desire considerations
What are the 7 components of a RPD?
Major connector Minor connector Rests Direct retainers indirect retainers reciprocal or bracing components Denture bases
What is a major connector?
connects the parts of a RPD from one side to the other side. principal function is to provide unification and rigidity to the denture
What is a minor connector?
connects other components to the major connector. principal function is to provide unification and rigidity to the denture
What is a direct retainer? What are the 4 elements that make up a direct retainer?
Also called a clasp or clasp unit. provides retention against dislodging forces. 1. rest 2. retentive arm 3. reciprocal arm 4. minor connector
What is an indirect retainer?
Unit of a class 1 or 2 partial denture that resists movement or rotation of denture base away from the residual ridge. Usually composed of a single component, a rest.
What is a denture base?
covers the residual ridges and supports the denture teeth
What is a Kennedy class 1 and class 2 partial denture?
Class 1 - bilateral edentulous areas that are posterior to all remaining teeth Class 2 - unilateral edentulous area located posterior to all remaining teeth
What is a kennedy class 3 partial denture?
Class 3 - unilateral edentulous area bounded by anterior and posterior natural teeth
What is a kennedy class 4 partial denture?
class 4 - a single, but bilateral (crossing the midline) edentulous area located anterior to remaining teeth
What are the 8 Applegate rules for applying the Kennedy classification?
- classification should follow extraction, not precede 2. If a 3rd molar is missing and not to be replaced, it is not considered in the classification 3. if a 3rd molar is to be used as an abutment, it is considered in the classification 4. If the 2nd molar is missing and not to be replaced, it is not considered in the classification 5. the most posterior edentulous area determines the classification 6. edentulous areas other than those determining the classification are called MODIFICATION SPACES 7. the extend of the modification is not considered, only the number 8. There is no modification space in class 4.
5 reasons teeth are lost
- dental caries 2. perio disease 3. trauma 4. congenital defects 5. iatrogenic reasons
What are the 5 possible consequences of partial edentualism?
- loss of vertical dimension of occlusion 2. opening of proximal contacts 3. uneven adjacent marginal ridges 4. food impaction 5. impaired self-cleansing of teeth
What is the PRIMARY PURPOSE of an RPD?
preservation of teeth that remain
When is RPD treatment planned and carried out?
Planned BEFORE other dental treamtnet Carried out AFTER other dental treatment
What are the 7 conditions for an ideal abutment for an RPD?
- no perio disease 2. vital tooth 3. no restorations 4. favorable crown/root ratio 5. favorable contours 6. favorable esthetics 7. favorable occlusion
What are 2 conditions that would make a tooth a poor abutment?
- Active perio disease 2. heavily restored tooth
When is an RPD design tooth-supported VS. tooth AND tissue supported?
tooth supported - When there is teeth posterior too the edentulous area tooth AND tissue supported - When there is no teeth posterior to the edentulous area
What is the function of a dental surveyor?
instrument used to determine the relative parallelism of two or more surfaces of the teeth or other parts of the cast of a dental arch
What is the path of insertion?
Path along which a prosthesis is placed intraorally
What do we call prepared surfaces on abutments for a parallel path of insertion?
Guiding planes
Ideally, how is path of insertion positioned?
Perpendicular to the occlusal plane
Specifically, what should guiding planes be prepared for? (3 pts)
- proximal plates 2. bracing arms 3. rigid portions of retentive clasps
What are the 3 sizes for metal gauges on a surveyor?
- 0.01” 2. 0.02” 3. 0.03”
What is the purpose of an analyzing rod (part of surveryor)?
thin straight metal rod used to analyze contours and undercuts.
What are the components of this surveryor?
A - Surverying platform
B - Vertical upright column
C - Cross arm with spindle housing
D - Vertical spindle with tool holder; E - Screw to lock the spindle; F - Tool adapter holder; G - Surveying tool holder; H - Surveying table; J - Model clamp; K - model table lock nut; L - Model rotating ball and socket; M - Ball rotating ring; N - Tool rack; O - Storage compartment; P - Model clamp Lock nut
Wax Trimmer
What is a wax trimmer?
tool with a straight sharp edge, which parallels the surveying arm. used to contour waxed crowns for partial denture abutments.
Difference between Tripod lines and transfer points?
Tripod lines - used to replicate the position of the survey table. placed on soft tissues and used on every cast (not as accurate as transfer points)
Transfer points - Used to replicate the position of the survey table. placed on every cast but used specifically for the final cast. (it is the most accurate because it is placed on hard tissues, which do not change (unlike soft tissues))
