I had a chance to check this book out of the library for two weeks and then I bought one. This book really prepares you for the National Board. It covers the materials, it gives you case studies, and it tests your knowledge at the end of each section. The material is very well written and easy to understand and it has a mock test in the back to see how well you know your material. I was reviewing perio and radio and I was learning new material that my instructors didn't cover and understanding concepts that were not clear to me. The book is so well written that I couldn't put it down. Buy this book! Even when your done with the National Boards its great referance to have around.