Ahmed Gaser Saeed Omara, Mohamed Seddik M. Kamel And Waleed Mohamed Elshahawy ,

ABSTRACT

Objectives: The Purpose Of This In-vitro Study Was To Study And Compare The Fracture Resistance Of Visiolign And Feldspathic Porcelain On Zirconium Core Methods: Specimens Consist Of 20 Samples Of Lower Mandibular First Molar Which Was Ready Made From Ivory Teeth (nissin, Japan) Were Mounted In An Acrylic Blocks With Standard Preparation. Production Of Zirconia Core Was Done With The Aid Of Computer Aided Designing /computer Aided Manufacturing (CAD/CAM) System. Standardization Of Restoration Was Done With Standard CAD/CAM Wax Pattern Design. Twenty Specimens Were Equally Divided Into Two Groups. In The First Group, 10 Samples Were Veneered With Feldspathic Porcelain . In The Second Group, 10 Sample Were Veneered With Visiolign, Fracture Resistance Was Tested For All Specimens Using Universal Testing Machine. The Failure Mode Was Evaluated As Repairable Or Non -repairable Result: Fracture Resistance : For Porcelain Veneered Group, It Was Found That Thermo-mechanical Aging Affected Fracture Resistance Significantly; For Visiolign Veneered Group, It Was Found That Thermo-mechanical Aging Affected Fracture Resistance Non-significantly Where Non-aged Subgroup Recorded Higher Nonsignificant Mean Value Than Aged Subgroup; Porcelain Vs. Visiolign Veneered Group For Aged Subgroups. It Was Found That Porcelain Veneered Group Recorded Higher Fracture Mean Value) Than Visiolign Veneeredmean Value. The Difference Between Both Groups Was Statistically Non-significant. For Non-aged Subgroup. It Was Found That Porcelain Veneered Group Recorded Higher Fracture Mean Value Than Visiolign Veneered Mean Value. The Difference Between Both Groups Was Statistically Significant. Effect Of Veneering Material It Was Found That Veneering Material Affected Fracture Resistance Significantly Where (Porcelain Veneered Mean Value >Visioning Veneered Mean Value) As Indicated By Two-way ANOVA (p=0.0384< 0.05)

Conclusions: It Was Found That Visiolign Is Durable And Has Comparable Fracture Resistance To Feldspathic Porcelain On Zirconium Core. The Common Mode Of Failure In Veneered Restoration Is Repairable .