This text offers dental hygienists a comprehensive and easy-to-understand presentation of periodontics. The evidence-based approach to periodontal care emphasizes use of research as the foundation for clinical decision making. This edition has more of the popular "Focus on Patients" and "Patient Case Study" features that help students apply concepts to actual patient treatment. A new "Patient Applications" feature presents critical thinking exercises using simulated patient cases. This edition has approximately 200 new illustrations, including new full-color clinical photographs. A bound-in CD-ROM includes an image bank of full-color photographs. CD-ROM Alert icons in the text direct students to these photographs.