Finishing of restorations

Checking and adjustment of inlays

The control process begins with a visual inspection of the inlay. The surface must be clean, free of pores and protrusions that could disrupt adaptation. Any defects at the margins of the prosthesis indicate that it must be remade. It is strictly forbidden to correct the shape of the restoration without first comparing it with the tooth cavity on the model and in the oral cavity.

Checking accuracy is strictly carried out in two stages:

1. On the plaster model. The inlay is gently inserted into the bed. If there is resistance, articulating paper is used to locate areas that hinder seating (supraoccluded contacts), and they are ground down.
2. In the oral cavity. After cleaning the prosthetic bed, the inlay is tried in. To obtain clear imprints of supraoccluded contacts, the articulating paper is pre-moistened.

Once the inlay is easily inserted and removed, marginal adaptation is evaluated with an explorer and occlusion is checked. Excess material is removed until teeth interlocking becomes comfortable. The adjustment is completed by polishing the margins to create a smooth transition to hard tissues.

Cementation of restorations

Before final placement, the prosthesis is disinfected with alcohol and dried with ether. The abutment tooth is isolated from saliva with cotton rolls, treated with alcohol-soaked cotton pellets, and dried with warm air.

The choice of luting agent depends on the restoration material:

• Glass-ionomer cement is used for metal inlays.
• Dual-cure composites are used for ceramic cementation.

The cementation technique involves applying the material to the prosthesis surface and into the tooth cavity. Then the restoration is placed into position, pressed down, and the patient is asked to close their jaws in the centric occlusion position. Excess cement is removed with a filling instrument after 5–7 minutes, resting the hand on adjacent teeth to avoid injuring the mucosa. Interdental spaces are cleaned with an explorer or a matrix.

Specifics of working with crowns

The steps for inspecting and adjusting artificial crowns have their own specific features depending on the material.

Stamped crowns Quality assessment begins on the plaster die. The crown must have a smooth surface without folds, tightly embrace the tooth neck, and correspond to the anatomical shape. The crown margin must overlap the clinical neck by 0.3–0.5 mm. In the clinic, the prosthesis is tried on the tooth: it should slide easily over the stump, dipping minimally into the gingival sulcus. If the crown is narrow (due to errors in the impression, engraving, or on the die), it is sent for restamping.

Acrylic crowns Preparation for acrylic requires the removal of a larger volume of tissue (up to 1.5 mm) to ensure material strength. Laboratory steps include modeling with clear wax with minimal pocket depth (up to 0.5 mm), investing in a flask in a vertical position, and replacing the wax with acrylic resin.

When cementing crowns, it is important not to apply excessive force to avoid displacing the structure. Residues of zinc phosphate cement are washed off with a special solution, after which the patient must rinse their mouth.

Class and exam questions

What else to study on this topic

• Laboratory steps for fabricating stamped crowns
• Double-impression technique for acrylic crowns
• Errors in tooth preparation for various types of crowns
• Materials and alloys for stamped crowns
• Technology of replacing wax with acrylic in crown fabrication

Other topics in "Chapter 9. Restoration of anatomical form and function of the tooth"

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.