Lower Standard Spring Retainer
Appliance Purpose / Function:
(1) Mushroom Spring- .022 spring wire
(2) Adams Clasps- .028 stainless steel
(1) Trans Palate Wire- .036 stainless steel
(1) Lingual Support Wire- .036 stainless steel
(1) Body wire .036 stainless steel
Appliance Fabrication Standards:
- Uniform overall thickness of approximately 2.5mm
- Standard acrylic plate coverage only with exposed mushroom spring below the omega portion of the spring.
- All borders must be tapered towards the tissue with a rounded edge (thin, sharp knife-like edges not accept-able)
- Acrylic must be trimmed at the height of the gingival third of each posterior tooth and must not interfere with opposing cusps
- Acrylic must have full contact with all lingual sur-faces of every tooth involved in the requested plate design with the exception anterior teeth contacted by spring. There must be no “cupped out” areas around the teeth that can act as a food trap, instead the acrylic must butt directly against each tooth without dipping
- All lingual acrylic from lateral to lateral must be removed.
- The tissue side of the plate is generally left alone unless otherwise requested by the Client, but it must be inspected for pits or sharp areas. Pits must be patched with acrylic, and sharp areas must be care-fully ground smooth without removing too much acrylic .
- Contact central and lateral incisors in middle 1/3 of labial sur-face Note: can be bend to ideal arch.
- Loop must contour to the gingival margin of the canine in a rounded V shape
- Crossing occlusion distal to canines wire must fit tightly into embrasure with no space underneath
- Wire must fit snugly into the lingual side of the embrasure and follow the contour of the tissue with 1mm of space between it and the tissue (this will allow acrylic to flow behind the wire and fully encase it. Do not leave too much space here as this will cause the acrylic to be too thick in order to cover the wire.)
- A minimum 5mm foot must be bent on the end of the wire for acrylic retention
- The wire must be positioned so that it will be in the middle 1/3 of the acrylic and must follow the contour of the tissue with 1mm of space between it and the tissue (this will allow acrylic to flow behind the wire and fully encase it. Do not leave too much space here as this will cause the acrylic to be too thick in order to cover the wire
- Wire must contact (or be very closely contoured to) the central and lateral incisors on the lingual just low enough to avoid interference with the opposing arch
- At the middle 1/3 of the lateral incisors it must curve towards the midline forming an oval shape with the bottom portion of the oval running just above the gingival margin of the incisors
- In the middle 1/3 of the central incisors, the wire should be bent down towards the lingual support wire closely contouring to the tissue and it should rest on top of the lingual support wire following its contours and extending back to the middle of the first bicuspids.