Reference guide for denture crown and bridge restorations

Digital dentistry technology has injected new vitality into the development of stomatology. The development of modern stomatology is changing with each passing day, and new technologies and new materials are emerging in an endless stream. However, there are some key manipulation treatment techniques that still rely on the exquisite operation and fine skills of the physician, and the following mainly describes the clinical examination steps, problem manifestations and related clinical skills of crown and bridge try-on.

Fitting of restorations

1. Evaluate the prosthesis on the type before trying

Before trying, it is necessary for the physician to check the fit of the crown and the die. Through the examination, the doctor can find possible problems with the crown in terms of edge fit, aesthetics and bite.

In general, common problems can include: too tight contact between adjacent surfaces, small protrusions on the tissue surface of the casting, overstretched crown edges, insufficient extension of crown edges, die damage, etc.

1. The contact between the adjacent surfaces is too tight

It is usually caused by die positioning, inaccuracies or wear and tear at the collar contact points.

Solution: When the crown is in place, check whether the die is displaced, and determine the contact point that is too tight by biting the paper, and polish and polish.

2. There are small protrusions on the tissue surface of the casting

It is usually caused by the appearance of air bubbles during embedding.

Solution: Grind off the small round diamond.

3. The edges are too stretched

Can be caused by poor impression quality, poor die trimming, excess untrimmed wax or porcelain on the crown edge.

Solution: Trim the axial surface of the crown and polish it, or consider returning the restoration to the lab for reconstruction.

4. The edge is not stretched enough

This is due to poor impression quality, poor die trimming, and inability to determine the finishline.

Solution: Re-take impressions and create restorations

5. Die damage

This can be caused by damage to the finish line due to the technician's carelessness, or air bubbles on the casting that wear out when they are in place on the die.

Solution: Carefully inspect the cause of the die damage and return it to the lab for reproduction if the prosthesis does not fit in place after removing air bubbles or small protrusions and trimming the excessively long edges.

The crown is in place

After the prosthesis is examined on the prosthesis, the patient's intraoral temporary prosthesis should be removed and the temporary adhesive remaining on the tooth should be completely removed, with particular attention to the removal of adhesive residue in the retaining sulcus or in the gingival sulcus. Physicians can gradually determine the cause of the failure to sit in place using the following series of tests:

1. Make sure that there is no residual temporary adhesive or gum tissue interference;

2. Check and adjust the contact of the adjacent surface that is too tight, and check the damage of the contact area model at the same time;

3. Check the obvious errors related to the technician's production, including bubbles, nodules, die defects and edge defects of castings, and use burs to remove bubbles and nodules of castings;

4. For the edge that is too extended, it must be trimmed from the outside of the crown but not from the inside of the crown;

5. Where the crown cannot be in place, all the imperfections need to be gently ground off with burs and then tried again, and the final evaluation of the restoration in place is carried out.