1. The “UCLA” abutment;Lewis;Int J Oral Maxillofac Implants,1988
2. A prosthodontic overview;Beumer;Int J Prosthodont,1993
3. Ceramic abutments-a new era in achieving optimal esthetics in implant dentistry;Yildirim;Int J Periodontics Restorative Dent,2000
4. Experimental zirconia abutments for implant-supported single-tooth restorations in esthetically demanding regions: 4-year results of a prospective clinical study;Glauser;Int J Prosthodont,2004
5. Considerations of implant abutment and crown contour: critical contour and subcritical contour;Su;Int J Periodontics Restorative Dent,2010