Individual Tray 244h57

Individual Tray

國泰汐止分院 牙科第一年住院醫師 楊舒涵

Object 

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Improves the accuracy of an elastometric impression by limiting the volume of the material Opposite is true for reversible hydrocolloid

Tray material 1.Autopolymerizing acrylic resin 2.Thermoplastic resin 3.Photopolymerized resin

Autopolymerizing materials 

Ostron

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Tray resin

Thermoplastic resin Easy Tray: soften in water bath and adapted manually to the spaced cast 

Vacuum formed tray: much more thicker and more rigid than those used for make provisional restorations 

Light-polymerized materials 

Triad VLC resin custom tray material: adapted to the spaced cast

Triad Visible Light Cure System 

Outline for relief wax may be drawn on the cast, usually 2 to 3 mm short of tray border

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Block out undercuts on the cast with wax or molding compound

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Baseplate wax is adapted to the edentulous or partially dentulous cast for tissue relief and trimmed to the desired outline. http://trubyte.dentsply.com/pro/prod_triadcustomtray.shtml

Triad Visible Light Cure System 

Paint TRIAD Model Release Agent (MRA)

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TRIAD TruTray or Original Blue Tray Material. Carefully adapt it to the cast and trim with a sharp blade

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attach a handle by moulding excess material

http://trubyte.dentsply.com/pro/prod_triadcustomtray.shtml

Triad Visible Light Cure System

http://trubyte.dentsply.com/pro/prod_triadcustomtray.shtml

Evaluation 

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Tray rigidity is important Resin thickness of 2~3mm are needed for adequate rigidity Clearance of tray and the teeth should also be 2~3mm Greater clearance is necessary for the more rigid polyether

Custom tray for FPD

Tray border 

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On diagnostic cast, using a pencil: approximately 5mm apically to the crest of the free gingiva Maxilla: covering the entire palate is not necessary (but necessary if removable appliance is planned) Posterior border should not extend farther than the junction of hard and soft palate

Space for impression material 

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Baseplate wax 2.5mm thick, trim wax margin back to pencil line just visible Or dripping cast in molten wax 3~4 times

Stopper placement 

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Three stops maintain even space for the impression material On non-centric cusp of teeth that will not be prepared If all teeth are involved, use larger soft tissue stop: Crest of alveolar ridge; Center of the hard palate Made by removing wax at an angle of 45 degrees to the occlusal surface

Tray fabrication 

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Tinfoil on wax prevent melt Gently adapt resin with consistent thickness to the cast Handle made; buccal ridges can also be added After polymerizing, trim with bur

Evaluation 

Rigid; thickness 2~3mm

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3~5mm cervical to gingival margin

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Shaped to allow frenum, muscle attachments

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Stable on cast; stoppers maintain impression thickness 2~3 mm

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Handle fit between pt's lip

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Pressure to prevent lifting while setting

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Made 9 hours before using; or 5minutes in boiling water then cool to room temperature

Custom tray for CD

Tray border 

Preliminary impression outlined with marker on the preliminary impression or poured cast

impression material and tray 

ZOE: close fitting tray

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elastomer, alginate: Spaced custom tray

maxillary 

provide space : (not used if ZOE as impression material) baseplate wax; 1 mm thick; within outlined border ;posterior seal should not covered by wax spacer

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tray: 2-3 mm thick; a stepped handle at anterior region

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Premise: all denture-bearing area reflected in the tray's extension

border molding – tray preparation 

Wax left when border molding

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Space for border molding custom tray reduced to 2mm shorter of the reflections

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Tray contains hamular notch and extend 2mm posterior to the vibrating line

Border molding 

Record all simultaneously - polyether reduced insertion number avoid errors

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Record in sections – stick impression compound

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Section: labial =>buccal vestibule=>posterior palatal area

Border molding with polyether Adhesive

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留下 wax spacer, 但把靠近 border 的修掉

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混 polyether 但 catalyst 少一點

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用 syringe 加在 border 和 palatal seal( 用沾水 的手塑型 ) 

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lip 拉高 ,tray 放入

檢查 border 如果材料不夠就用手沾口水把旁 邊的材料移過來 

Border molding with polyether(maxillary)  @lip 上外下內拉

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@frenum 外下內前後拉

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@buccal flange 外下內拉

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@ 張大嘴 下頷左右動

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Setting 後 tray 拿出

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檢查 border: 應為 rounded, 小缺陷以 polyether 補 ,tray 的過度延伸會透出 polyether. 應調整 

preparing tray for final impression 

remove wax , excess material

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Buccal frenum 間 , flange 厚不要超過 2,5~3mm 進入 undercut 的也拿掉

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最後除了 posterior area , 再均勻拿掉 0.5mm

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Holes : palate of tray ( if soft tissue mobile, relief residual ridge)

Mandibular 

wax spacer:1 mm

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below the mylohyoid ridge; on crest and slopes of the residual ridge

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buccal shelf uncovered Handles: 

20 mm height

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anterior teeth

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1st molar region

border modeling  

wax left tray trim to 2 mm Shorter than limiting Structure

Movements, 

lip: 外上內

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buccal frenum : 外上內前後

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Cheek 頰上內

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閉口

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舌 : 伸、頂 palate

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開口

Evaluation 

必須能舌舔 vermilion border 時 , tray 無明顯 移位。

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移除 wax 和修掉 0.5mm molding material

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alveolar groove 和 retromolar pad 上每 10mm 打洞

Custom tray for RPD

Diagnostic cast 

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A new impression in a rigid stock tray must be made if extensive surgery and extractions were performed after making the diagnostic cast A duplicate of the diagnostic cast should be made, on which the individual tray can be fabricated

maxillary 

Outline tray border

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Wax spacer 2~3 m shorter than outline no wax over posterior palatal seal expose incisal edges of central incisor bevel wax

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block undercut

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If use alginate=>additional wax on teeth If rubber base or silicone=> 省略

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Release agent

maxillary 

Tray fabrication with handle

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Peel wax out

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rounding border of the tray

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Holes: alginate: at 5 mm interval ; throughout tray except alveolar groove area (for lock material) mercaptan rubbers (polysulfide): (polysulfide) only median raphe and incisive papilla (for relief)

mandibular 

Wax spacer does not cover the buccal shelf region (these areas provide the primary for the mandibular RPD)

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Holes: alginate=>throughout tray alginate mercaptan rubber(polysulfide) => only alveolar groove (for relief)

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如果不使用 secondary impression technique, 則 使用 individual tray 印模可視為做活動假牙的 必要步驟

Tray design

British Dental Journal 187, 423 - 426 (1999);The design and use of special trays in prosthodontics: guidelines to improve clinical effectiveness