RPD

89問 • 2年前

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The branch of dental arts and science that deals with the replacement of missing teeth and oral tissues to restore and maintain oral form, appearance, function and health.

Prosthodontics

The specialty of dentistry that replaces missing teeth with a removable prosthesis.

Removable Prosthodontics

Removable prosthodontics includes 2 disciplines:

Removable Partial Denture, Removable Complete Denture

Referred to as a partial, replaces one or more teeth in the same arch; can be removed and replaced in the mouth by the patient.

Removable Partial Denture

A provisional or temporary denture used for short interval of time to provide.

Interim Denture

Interim denture provides:

Esthetics, Mastication, Occlusal Support, Convenience, Conditioning of the patients

RPD is generally preferred in the following conditions:

When more than 2 posterior teeth or 4 anterior teeth are missing., If canine and two of its adjacent teeth are missing., When there is no distal abutment tooth., Presence of multiple edentulous spaces., If teeth adjacent to edentulous spaces are tipped, they cannot be used as an abutment for fixed prosthesis., Severe loss of tissue on the edentulous space.

Contraindications for a Removable Partial Denture

Lack of suitable teeth in the arch to support, stabilize, and retain the removable prosthesis., Rampant caries or severe periodontal conditions that threaten the remaining teeth in the arch., Lack of patient acceptance for esthetic reason.

Cast metal skeleton that provides support for the remaining components of prosthesis.

Framework

Joins various part of the partial together.

Connectors

Two Types of Connectors

Major Connector, Minor Connector

A portion of a tooth or that portion of an implant that serves to support and or retain a prosthesis.

Abutment

Known as a clasp, it supports and provides stability to the partial denture by partially circling an abutment tooth.

Retainer

A metal projection designed to control the seating of the prosthesis; rigid extension to transmit vertical forces.

Rest

Constructed from wither acrylic or porcelain.

Artificial Teeth

Systematic investigation of an unnatural condition, and the determination of its cause.

Diagnosis

Obtained from the dental and medical histories, extraordinary and intraoral examination, roentgenographic survey, and analysis of articulated diagnostic casts.

Data

The number of restored teeth, signs of recurrent decay, and evidence of decalcification should be noted before decision is made on the unrestored teeth as potential abutment selections.

Visual Examination

To measure the quality of bone support for potential abutment teeth whereas it will withstand increased forces upon movements of the partial prosthesis.

Roentgenographic Analysis

Consists of serious illness that needs prophylactic medications, allergies, current medications, family history, tobacco, and alcohol habits.

Medical and Dental Histories

Diagnostoc casts involves:

Need for Bilateral Bracing and Support, Restoration of Facial Contours

Factors Affecting Treatment Plan

Number of teeth to be replaced, Residual Dentition Condition, Patients Health, Patients Expectations, Time, Laboratoy Competence

Alternatives to Removable Partial Denture.

No Treatment (Shortened Dental Arch), Fixed Partial Denture, Implant Supported Prosthesis, Complete Denture

Quality of the denture that resists vertical forces of dislodgment.

Retention

Defined as the quality of the prosthesis to be firm, stable, and or constant to.

Stability

Defined as foundation on which a dental prosthesis rest or to hold-up and serve as a foundation.

Support

Line encircling a tooth, designated its greatest circumstances at a selected position determination by dental surveyor.

Height of Contour

An instrument in diagnosing and guiding the appropriate tooth preparation and verifying that the mouth preparation has been performed correctly for parallelism.

Dental Surveyor

Tools of Surveyor

Analyzing Rod, Led Marker/Carbon Marker, Wax Trimmer

Tooth portion that lies between the height of contour and the gingiva; 1mm compressibility attachment of mucosa.

Undercut

An angle viewed between a vertical rod contacting an abutment tooth and the axial surface of the abutment cervical to the height of contour.

Angle of Cervical Convergence

Angle of Cervical Convergence Guide:

Path of Removal, Path of Insertion, Path of Displacement

Prepared axial surface of the teeth against which the removable partial denture glides as it is inserted and removed from mouth.

Guide Plane

Path followed by denture from its contact with the teeth until its fully seated.

Path of Insertion

Path of insertion that may be created at sufficient guide surfaces are contacted by the denture.

Single Path

Insertion exist where guide surfaces are not utilized.

Multiple Path

Requirements of a Rest:

Sufficient thickness of metal to prevent fracture; 1.5mm for chrome cobalt, 2mm for gold., Should be placed on surfaces which would direct forces along the long axis of the teeth; not inclined., Should be extended to as close to the center as feasible to promote axial direction of forces., Should be placed in rest seats which demonstrates smooth and rounded internal line angle., Rest Seats should be on enamel or nay restoration that has been proven to resist fracture and distortion when subjecter to applied forces.

DO'S

Amalgam, Metal Inlay, Gold, Porcelain

DON'TS

GIC, IRM, Composite

Portion of tooth prepared to receive rest.

Rest Seat

Preparation of Rest Seats.

Light Pressure, Water Spray, Minimal Heat, Keep on Enamel, No Anesthesia

Types of Rest:

Occlusal Rest, Incisal Rest, Lingual Rest

Under occlusal rest, Conventional should be/have:

1mm reduction on marginal ridge, Spoon shaped, Long as it is wide, 2.5mm base, 1/2 width of the tooth at the cusp tips

Under occlusal rest, Extended should be/have:

Tooth borne cases severely tilted., To ensure transmission of forces towards the long axis., In a form of onlay to restore occlusal plane., 1-2mm bevel on the buccal and lingual occlusal surfaces to allow the extended rest.

Is saddle shaped, concave when viewed frontally, convex when viewed proximally, greater mechanical leverage than a cingulum rest; placed mesio or disto incisal angle; common on mandibular incisor.

Incisal Rest

Preferable than incisal rest because it is placed closer to horizontal axis of rotation; also known as cingulum rest.

Lingual Rest

Types of Lingual Rest.

Cingulum Rest, Ball Rest

Inverted V or U shaped when viewed from the lingual; V or U shaped when viewed from proximal.

Cingulum Rest

Preparation of Cingulum Rest.

Medium or large but should be utulized along the long axis., Horizontal direction results to undercut., Avoid opposing occlusion, 1.5-2mm metal clearance

When cingulum is poorly developed can provide acceptable strength and longevity.

Bonded Cingulum Rest

Prepared on mesial of the canine teeth when use of typical cingulum rest; spoon shape, easily incorporated with crowns, more difficult due to incline.

Ball Lingual Rest Seat

Part of the removable partial denture which connects the component on one side of the arch with those on the opposite side; directly or indirectly attached; provides a rigid union.

Major Connectors

Functions of a Major Connector:

Unification, Stress Distribution, Cross-Arch Stabilization

Major connector unites all components and acts as one.

Unification

Major connector distribute functional loads to all abutment subjected to extreme loading.

Stress Distribution

Uniting one side to the other bracing elements providing stability; for twisting and torquing forces.

Cross-Arch Stabilization

Major Connector Requirements:

Must be rigid, Bony or soft tissue prominence should be avoided during placement and removal., Borders are placed atleast 6mm from free gingival margins., When 6mm cannot be obtained, metal may be extended to the cingulum., No relief of maxillary major connector is necessary except torus., Metal should not have high polish on tissue surface., All borders must be tapered., In rugae region, border should pass through valleys of rugae.

Rigidity includes:

Using more rigid alloy (Chrome-cobalt > gold alloys; cast > wrought metal), Using 1/2 round or pear shaped bars., Increased bulk as length increased., Corrugating linguo-plate or rugae areas.

Non-Interference with Soft Tissues

Attached Gingiva, Free Gingiva

T or F. Max. 4-6mm, soft palate; Mand. 3-4mm, tongue and floor of the mouth

True

Locate margins away; eliminate traps or large concavities minimize ________

Food Impaction

Smooth transition from connector to denture base; all line angles and edges should be smooth and rounded; bulk should be reduced enough so as not to interfere with speech or appearance.

Unobtrusive

Scribing of a shallow groove on the maxillary master cast outlining the palatal major connector exclusive of rugae areas.

Beading

Types of Maxillary Major Connector.

Single Palatal Bar, U-Shaped Palatal Connector, Single Palatal Strap, Anterior-Posterior Palatal Bar, Anterior-Posterior Palatal Strap

Must have concentrated bulk for rigidity; narrow antero-posterior; don't use.

Single Palatal Bar

Horse-shoe shaped palatal connector; most objectionable; only for torus.

U-Shaped Palatal Connector

Should be about 8mm in width; class III cases.

Single Palatal Strap

Variation of anterior-posterior palatal strap; double palatal bar connector; more objectionable to the patient.

Anterior-Posterior Palatal Bars

For class I, II, and/or IV cases; maximum rigidity; minimum bulk; especially for Torus Palatinus.

Anterior-Posterior Palatal Strap

Full shallow palatal vault; maximum tissue support; maximum stress distribution; six or less anterior teeth remains.

Palatal Plate

Dangerous; can cause aspirations.

Unilateral RPD

Types of Mandibular Major Connectors.

Lingual Bar, Linguoplate, Sublingual Bar, Cingulum Bar, Lingual Bar with Cingulum Bar, Labial Bar

Most commonly used in mandibular; 4mm width; tear-drop on tongues side, flat in tissue side.

Lingual Bar

Lingual bar with extension over cingula of anterior teeth; use where lingual bar cannot be used; rest at each end of plate; 4-6mm clearance.

Linguoplate

More inferior and posterior in placement to the lingual bar; contraindicated for shallow floor of the mouth, high frenal attachment and tori.

Sublingual Bar

When linguoplate is the major connector of choice but axial alignment of anterior teeth is such that excessive block out of interproximal undercuts must be made.

Cingulum Bar

Kennedy bar or double lingual bar; not advisable.

Continuous Bar Retainer

For lingually tipped teeth and for patients with lingual tori; swing lock design.

Labial Bar

Rigid component that links the major connector to other components of partial denture.

Minor Connector

Types of Minor Connector.

Direct Retainer, Indirect Retainer, Denture Base

Functions of Minor Connector.

Unification and rigidity, Stress Distribution, Bracing through contact with guiding planes.

Types of Minor Connector.

Truss Arm, Proximal Plate, Ridge Mesh, Finish Lines, Rests

Connects the major connector with the rest.

Truss Arm

Contacts the proximal surface/guiding planes of teeth.

Proximal Plate

Portions of framework where denture bases attach; retentive struts for acrylic resin; 2/3 lower edentulous ridge length.

Ridge Mesh

Types of Ridge Mesh.

Tissue Stop, Open Lattice, Mesh, Posts

Stop button; integral mesh part; prevents distortion; small metal projection.

Tissue Stop

T or F. Max. covers whole ridge; Mand. cover 1/3 of ridge.

False

Distal terminal abutment and continuous with proximal plate.

Finishing Index

FPD Reviewer

Kel Sy · 77問 · 2年前

FPD Reviewer