This book is intended to assess the effect of different hydrofluoric acid etching duration on the translucency, flexural strength and surface topography of a lithium silicate-based glass ceramic (LS) . Where LS (Obsidian) samples were constructed and divided into four groups according the duration of hydrofluoric acid (HF) application including first group which is a control as the received samples didn't receive any surface treatment, second group the ceramic sample surfaces were etched with HF for 10 seconds; following the manufacturer¿s recommendations, third group ceramic surfaces samples were etched with HF for 30 seconds and Fourth group the ceramic samples surfaces were etched with HF for 60 seconds. All treated samples were evaluated for translucency using spectrophotometer, flexural strength using universal testing machine and surface topographic analysis using SEM and profilometer. Obtained values were statistically analyzed and tabulated.

An Egyptian dentist that decided to study dentistry as she believes ¿Dentistry is a magical mix of Art & Science¿. Escalated from a highest honor graduate to a Teaching Assistant at Fixed prosthodontics , acquired a masters degree in this field, which created a solid dentistry background. At this book she is publishing her thesis.