2PENSAK T. Myths about gingival response to crowns [ J ]. J Can Dent Assoc, 2005, 74 (9) : 799-$01.
3KIM C S, CHOI S H, CHAI J K, et al. Surgical extru- sion technique for clinical crown lengthing: report of three cases[J]. Int J Periodentics Restorative Dent, 2004, 24 (4) : 412-421.
4DONOVAN T E. Factors essential for successful all-ce- ramic restorations [J]. J Am Dent Assoc, 2008, 139(Suppl) : 14S-18S.
5SPEAR F, HOLLOWAY J. Which all-ceramic system is optimal for anterior esthetics? [J]. J Am Dent Assoc, 2008, 139 (Suppl): 19S-24S.
6KALKWARF K L, KREJCI R F, EDISON A R, et al. Subjacent heat production during tissue excision with e- lectrosurgery[J]. J Oral Maxillofac Surg, 1983, 41 (10) : 653-657.
