An acrylic resin shell with guide extensions for accurate positioning of provisional restorations

Abstract

Infante and Lee 8. Fill the putty matrix with autopolymerizing acrylic resin of the selected shade, (Jet Tooth Shade Acrylic; Lang Dental Manufacturing Co, Inc) and place over the prepared tooth of the cast. 9. Visually verify that the matrix is seated completely over the cast and place rubber bands around the matrix and the cast to maintain an adequate and stable spatial relation. 10. Place the cast along with the matrix and rubber bands in warm water inside a pressure pot (Acri-Dense VI Pneumatic Curing Unit; GC Lab Technologies, Inc, Alsip, Ill) at 0.14 MPa and allow the acrylic resin to polymerize according to the manufacturer’s instructions. 11. Retrieve the polymerized shell from the cast and trim the excess material with an acrylic resin cutting bur (Tungsten carbide cutter H79EF HP 040; Komet USA, LLC, Rock Hill, SC). Do not trim the extensions at this time (Fig. 2). 12. Create a vent hole 2.0 mm in diameter, on the midlingual area of the shell for the reline material to flow out and allow proper seating of the shell. 13. Prepare the tooth/teeth to receive the desired restoration. 14. Seat the provisional shell over the preparation and visually verify that the guide extensions are completely seated over the adjacent teeth. Adjust the intaglio if needed. 15. Apply a thin layer of petrolatum jelly (White Petroleum Jelly; Geritrex Corporation, Mount Vernon, NY) to the prepared tooth. 16. Reline the provisional shell with the same autopolymerizing resin material and guide its positioning over the prepared tooth by completely seating the guide wings over the adjacent teeth (Fig. 3). 17. Allow the relining material to polymerize while intermittently removing and reinserting and irrigating with water to cool. 18. Remove the provisional crown from the preparation. 19. Cut off the guide wings and finish and polish the provisional crown (Fig. 4). REFERENCES