The clinical performance of current adhesives has significantly improved allowing resin restorations to be placed with a highly predictable level of clinical success. High clinical retention rates are consistently recorded for today's systems that are documented to produce qualitative hybrid layers.Unfortunately, retention is a very objective criterion, whereas assessing clinical micro-leakage is much more subjective and requires training and calibration among examiners.To satisfy the growing esthetic demands of today's dental patients, improvements in materials and procedures have been made to make it possible to reproduce the natural appearance of natural teeth with direct and/or indirect esthetic restorations.