Oxford temp: a provisional crown and bridge material

An accurate fit and margination is essential to ensure and maintain pulpal health.

Material selection

It has always been said that patients don’t know what they like until they see something they don’t like. Start by talking to patients about the steps during the restorative phase and give reassurance that the provisional restorations are a blueprint for the final restorations. We will need their help in the shade selection and functional aspect in this stage of the restoration.

Choosing a provisional material that not only blends with the natural shade of the teeth is easy while choosing a material that mimics natural tooth structure, polishes well and has an appearance of translucency and vitality but performs with strength and outstanding elastic modulus is more difficult. Oxford Temp by Oxford Scientific Dental Products is a provisional crown and bridge material formulated with multifunctional methacrylic esters but without methylmethacrylate.

Shades of material

If a patient is looking for a standard shade to blend with his or her natural teeth, the assistant can chose any standard shade for anterior or posterior provisionals. If the patient has chosen a whiter shade based on the Chromoscope Shade Guide (Ivoclar Vivadent) or the Vita 3D Bleach Shade Guide (Vident), Oxford Temp has shades that reflect on these choices by offering the Oxford Bleach shades for those patients that want whiter than A1.

Fabrication of direct anterior provisional restorations

Before fabricating the provisional, fabrication of the putty matrix is formed with Express Putty (3M ESPE) over the wax up. After removal of the putty matrix, reline the matrix with a light body wash (Imprint 2, 3M ESPE) and seat back on the wax-up to capture all the detail that was designed in the wax-up. Allow the impression material to set.

Lubricate all gingival tissues facially and lingually along the gingival margins with a vitamin E oil that is very viscous, such as Elieve from Centrix.

Load the Oxford Temp toward the facial, making sure that the tip of the material is kept submerged in the material as it is extruded and not lifted until the teeth in the matrix have been entirely filled. This will help eliminate voids and bubbles. Seat the putty matrix on preparations and allow Oxford Temp to sit for four minutes, and do not remove until that time.

Using a timer will help to make sure that you don’t pull the matrix too soon. After the timer has gone off, remove the putty matrix.

Remove all material with an explorer or scaler off the margins and tissue. By using Oxford Temp, the material is released at the margins, which allows the assistant to remove the excess without asking the dentist to come and remove the excess with a carbide bur. Make sure all material is removed off the tissue and occlusal surfaces.

With Oxford Temp you’ll notice that the material is flexible and allows one to perform these steps with ease. In most cases, the Oxford Temp provisional is only polished with a Jiffy brush, by Ultradent, as the final step.

Fabrication of posterior provisional restorations

The dentist finalizes preparations and now the patient is ready for the provisional restoration. In most cases, dentist are leery of fabrication of a four-unit provisional.

Oxford Temp’s superior properties of compressive and diametric tensile strength with elastic modulus allow us to feel comfortable that we are fabricating a provisional restoration that is going to last for the patient, without breaking for the duration of the final restorative fabrication in the laboratory.

The procedure

A pre-operative impression is taken and set aside before preparation of a four-unit bridge. After preparation, Oxford Temp is placed in the pre-operative impression and placed back into the patient’s mouth on the preparations. After about 90 seconds, the pre-operative impression is removed and the provisional is trimmed for detail.

After marking the provisional margins and contact areas, mark the interproximal lines on both the buccal and lingual surfaces of the provisional to contour the interproximal separations. Place the separating disk in the handpiece and start with the interproximal separations between the margins to a depth of around 1 millimeter.

Use the separating disc in the interproximal area of the occlusal to give the look of single teeth. On the pre-molars, use carbide to contour the areas shown to define the buccal cusps. Make the mesial cusps on the lower first molars bolder than the distal cusps.

Contour buccal and lingual cusps. Work down into the depressions, rounding off the sharp interproximal edges. This gives the look of individual teeth. When trying in the provisional, check to see that there is going to be plenty of room for the patient to floss.

Starting in the central fossa, carve through the occlusal surface and down the buccal surface through the middle third area. With a pin grasps, apply enough pressure with the carbide to create a well-defined groove. Start in the distal fossa and work toward the distal at a 45-degree angle to produce the extra disectional groove. Contour through the occlusal table and curve down the buccal surface toward the distal. On the lower second molar, start in the central fossa and go through the occlusal table. Curve the groove slightly toward the distal on the buccal surface and polish.

By using occlusal stains (TetricColor, Ivoclar/Vivident; or Kolor Plus, Kerr), you can give the appearance of natural stain. Use a small amount, as this can be intense.

Dry the preparations, then with the dual cure Oxford Temp Cem, load the restoration and seat. Allow the material to set and remove the excess and adjust the bite.

Conclusion

With increased demands being placed on provisional restorations, new materials and techniques are being developed and some existing protocols are being refined to accomplish desired goals.

With the increase in patient demands for immediate esthetic results, provisional restorations need to mimic the final result in all aspects of shade, length, form and position, and the choice in dental material needs to be esthetic and functional like the final restoration.

 

(SOURCE: Oxford Scientific)