[Causes and management of gingival coloration caused by metal ceramic crows].
OBJECTIVE
To analyse the marginal gingival coloration caused by metal based ceramic crowns in 28 patients,and to explore the methods to remove or reduce this abnormal coloration.


METHODS
28 patients with metal based ceramic crowns developed gingival coforation. The period of wearing crowns ranged from 2 weeks to 3 years. To remove or reduce gingival coloration,the original metal based ceramic crowns were discarded. Temporary plastic crowns were utilized for 2 weeks. The cervical ceramic approach was used for rehabilitation,or the abutments were re-prepared for metal based ceramic crowns.


RESULTS
At the end of follow up,gingival coloration disappeared in patients managed with cervical ceramic approach. While in patients managed with second metal crowns, gingival coloration was improved greatly.


CONCLUSIONS
Gingiral coloration can be removed or reduced by cervical ceramic approach or re-fabrication of metal based ceramic crowns.
Wang
Hua
H
Department of Dentistry, Ruijin Hospital, Shanghai Second Medical University, Shanghai 200025, China.