The gradual loss of tooth enamel is a natural outcome of the aging process. The early depletion of this tissue could be attributed to various factors, such as the consumption of acidic foods and drinks, GERD, bulimia nervosa, drug intake, and the decrease in saliva production. The aforementioned lesions are referred to as dental erosions and exhibit non-carious features. By using biomimetic restorative dentistry, which mimics the overall appearance, biomechanics, and functional properties of the normal tooth, it is possible to restore the dentition that has been damaged. Partial coverage restorations, especially occlusal veneers with decreased thickness, are recognized as a conservative option for restoring the loss of vertical dimension in cases of severe occlusal erosions. Production of stronger and thinner restorations can be fulfilled by using computer-aided design and manufacturing (CAD/CAM) technology, ceramics with high resistance, refined bonding protocols, and durable cementation materials. The utilization of lithium disilicate ceramic restorations has become increasingly prevalent in the field of dentistry, particularly for posterior single crowns and partial coverage restorations. This is due to the exceptional physical properties exhibited by these monolithic ceramic systems. A novel zirconia-reinforced lithium silicate glass ceramic has been developed and made available for use in dental (CAD/CAM) applications. Zirconia powder (10% by weight) has been incorporated into the structure in order to strengthen this new form of glass ceramic through the mechanism of crack interruption. This type of treatment has progressed to the point where normal sound tooth structure could be maintained while adhesion is maximized. Inter-occlusal clearance and biomechanical considerations are the primary drivers for the tooth preparation needed for these extra- coronal restorations. This in-vitro study is planned to analyze the effect of different thicknesses of ceramic occlusal veneers and different surface treatments on fracture resistance.

Mansoura University in Egypt is where Dr. Maged Zahran earned his bachelor's degree in dentistry. In 2012, he graduated from Suez Canal University in Egypt with a diploma in endodontics. Then, in 2019, He get the Master's in restorative Dentistry from Mansoura University (Major operative, Major fixed prosthodontics, Major Endodontics). He has now enrolled as a doctoral student at Mansoura University's Fixed Prosthodontics Division. Ceramics, veneers, adhesives, and biomechanics are the primary areas of study. Eleven years’ experience in Ministry of Health hospitals o One year teaching Experience in restorative dentistry department, Mansoura University, Egypt o Eight years’ experience in his own dental clinic o Three months as an intern resident at Cairo University hospitals