SUMMARY
Occasionally but rarely we may have to use a tooth as a Swing-Lock abutment that has no naturally accuring undercuts. We have several solutions to treat such cases.
One very simple solution is to groove or dimple the tooth at the cervical region or place a filling in this same area with the some grooved or dimpled contour. The Swing-Lock metal framework or the cosmetic gingival veneer in such cases will engage this created undercut.
A second choice is to perform a gingivectomi and remove just enough tissue to expose a naturally occuring undercut area.
If a major restoration has to be done on a tooth that has minimum or no undercut areas, such as porcelain jacket crown, a gold veneer crown, or a gold coping the necessary precautions should be taken in each case. When a porcelain jacket construction is decided, the ceramist should be made aware that a definite undercut area should be formed where the normal cemento-enamel junction would have been on this tooth regardless of its length from the shoulder. When a gold veneer jacket crown construction is decided, the plastic or porcelain portion is designed so that it will abut an exagerated undercut (u) in the gold which will engage the labial bar for perfect retention. The remaining gold portion is designed for a normal lingual path of insertion. When gold coping construction is decided, it also should have an exagerated undercut area on the labial or buccal shoulder. In this case the labial section has to be disengaged from the undercut area on the coping by the labial opening arc before the case can be removed or inserted.
Primary Language | Turkish |
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Journal Section | Case Reports |
Authors | |
Publication Date | June 26, 2013 |
Published in Issue | Year 1978 Volume: 12 Issue: 1 |