Crown Margin vs. Composite Margin

An advanced dental decay was found on a 85 year-old male patient during a teeth
cleaning and exam. The decay was developing below an existing crown on tooth #31,
located on the mesial surface in the subgingival area.
Treatment options were discussed with the patient, and he agreed to get a crown
after a composite build-up.

Fig.1
Advanced subgingival dental decay was found below the existing crown of #31, hiding under the interdental papillae.

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Fig.2
The old crown was cut and removed, and crown preparation was performed after a composite build-up. The crown margin was placed on the composite surface on the mesial side—the decayed area—because the dental decay had progressed to the bone level, and the composite margin was preferred because of impression difficulty.

February2018Newsletter-fig2.jpg

Fig.3
I usually take two bitewing x-rays, with the first taken after proximal contact adjustment (using the Black Diamond Strip) but before cementation and one after cementation. In the second x-ray, after cementation, some remaining cement was found trapped in the interproximal space, and it was removed using the White Serrated Strip.

February2018Newsletter-fig3.jpg

Fig.4
With all of the cement removed and complete marginal seating achieved as shown on the 3rd x-ray, Interproximal Relief is confirmed with the Gray Final Polishing Strip.

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