Rpd Components Flashcards
Major connector
Part of a rpd that joins the components one one side of the arch to the opposite side
5 rpd components
Major connector Minor connector Direct retainer Indirect retainer Base Replaced teeth
Mandibular major connectors
Lingual bar
Labial bar
Lingual plate
Maxillary major connectors
Complete or modified palatal plate
Anteroposterior palatal plate
Anterior palatal strap
Lingual bar
6ga half pear shaped approx 4mm in height with superior border at least 3mm from fgm
Lingual plate
Used when fgm to floor of mouth is less than 7mm or anteriors are mobile and longevity is questionable
*30ga relief wax is used to make sure bar/plate doesnt contact tissue
Complete palatal plate
Posterior border must not impinge upon movable tissue
Modified palatal plate
Anterior border ends in valley of rugae not less than 6mm from fgm
- wide application to all classes mostly 1&2
- maximum support as plate rests on tissue
- contraindicated where tori are present
Labial bar form and usage
Same as lingual bar but placed buccally due to severe lingual inclination or remaining teeth
Minor connector definition
Connecting link between major connector or base of a rpd
Requirements of a minor connector
Must be ridged
Must not impinge underlying mucosa and mucosal surface is highly polished
Usage or minor connector
Minor connector and rest junction must be at least 1.5mm thick
Try to place inter proximally
Joins major connector at right angle
Should be 5mm from other vertical components
Direct retainer
Component or rpd used to retain and prevent dislodgment consisting of a clasp assembly or precision attachment
Parts: reciprocal arm, occlusal rest, retentive arm
Reciprocal Arm
Component of clasp assembly specifically designed to provide reciprocation by engaging a reciprocal guiding plane; it counteracts action of clasp during removal and insertion or rpd
Function of reciprocal arm
Resists lateral movement of prosthesis and potential ortho movement
Types: horizontal
Retentive arm clasps
- Clasp designed to provide retention by engaging undercut
2. Flexible segment of rpd that engages undercut on a abutment and is designed to retain prosthesis
Types of clasps (material undercut)
- Cast
- circumferential
- bar (INFRABULGE)
- Wrought
- circumferential
Types of clasps
- SUPRABULGE (occlusal approach)
- cast
- wrought
- INFRABULGE (gingival approach)
- cast
Denture base definition
Part of rpd that rests on foundation tissue and to which teeth are attached
Denture base acrylic usage
- can be in mand and max rpd classifications
- relined of edentulous ridge area changes
- attached to rpd framework via meshwork
**meshwork waxup on mand rpd is relieved off the ridge by using 24ga during block out of cast before duplication and waxing
Denture base metal
- used in class 3 or 4
- acrylic material associated w base is attached using small plastic beads at the time of base wax
Denture base finish lines definition
Planned junction or different materials
Types: internal acrylic bases only
- associates with junction between metal or rpd framework and acrylic base material
- formed by 24ga relief wax used to provide space for denture acrylic
Type: external (acrylic and metal bases)
-external and internal finish lines when present are not placed opposite of each other to prevent fracturing of base
Replaced teeth functions
Prevents movement of remaining teeth,
Restores masticatory efficiency, retain proper inter arch space, maintain aesthetics or facial contour, achieve distinct enunciation
Types of replaced teeth material
Acrylic
Porcelain
Metal : gold and chrome
Indirect retainer definition
Component of rpd that assists the direct retainer in preventing displacement of distal extension denture base by functioning through lever action on the side opposite of the fulcrum line when denture base moves away from tissues in pure rotation around fulcrum line
Fulcrum line axis
An imaginary line connecting most distal occlusal rests around which a rpd tends to rotate TOWARDS tissues under masticatory forces
Retentive fulcrum line axis
Movement of base AWAY from ridge around imaginary line connecting retentive clasp tips
What ga is used for wires
19ga
