A follow-up study of up to 5 years of metal-ceramic crowns in maxillary central incisors for different gingival biotypes.

The objective of this prospective clinical study was to evaluate the outcomes of metal-ceramic crown restorations in maxillary central incisors for different gingival biotypes in a Chinese population. One hundred single metal-ceramic crowns were fabricated for 100 patients (50 for thin gingival type and 50 for thick gingival type) from April 2007 to October 2007 and evaluated according to the World Dental Federation criteria at baseline and annually at all follow-up examinations for 5 years. Gingival recession was recorded at the same time, as well. The failure-free rate over the 5-year clinical trial for thin gingival type (78.0%) was significantly lower than that for thick gingival type (94.0%; P = .02). Seven crowns were ranked as failures because of esthetic problems in patients with a thin gingival type. The restored teeth with a thin gingival type exhibited more gingival recession (1.09 ± 0.22 mm) than the control teeth (0.31 ± 0.16 mm; P = .01). Gingival biotype had a significant effect on the outcomes of metal-ceramic crown restorations in maxillary central incisors.