Ahmad M.M. Ali Goma?a And Manal Rafie Hassan,

ABSTRACT

Objectives: The Purpose Of This Study Is To Investigate The Aging By Thermocycling And Solutions With Different PH On Surface Roughness And Fracture Toughness Of Two Different CADCAM Materials.

Materials and Methods: Fifty Rectangular Samples (n=50) From Two Different CADCAM Materials. Vita Enamic CADCAM Blocks, Polymer Infiltrated Ceramics Blocks (En) And IPS E.max CADCAM Blocks, Lithium Disilicate Glass Ceramics Blocks (E Max). Samples Were Prepared Into Dimensions (14 X 2 X 1.5 Mm). . A Single Notch Was Prepared In Each Sample. The Notch Width Was Less Than Or Equal 0.3 Mm � 0.01mm. The Tip Of The Single Notch Was Located On The Long Surface Of The Sample At 0.24 To 0.48 Mm From The Bottom Left Corner. Samples Were Divided Into Two Main Groups, According To Type Of Material , Each Group Was Composed Of 25 Specimens, Each Group Further Divided Into Five Sub Group; Con= Control Group, Tc= Subjected To Thermocycling Only, Tc/N Stored In Neutral Media (Distilled Water PH7) + Thermocycling, Tc/Alk Stored In Alkaline Media (Sodium Bicarbonate PH 9) + Thermocycling, Tc/Ac Stored In Acidic Media (Coca Cola PH 2.2) + Thermocycling. Thermocycling Performed At 5-55oc For 10,000 Cycles. Aging In Solution Was Done At Room Temperature For 30 Days. Surface Roughness Measured For All Specimens By Profilometer Then Samples Subjected To 4 Points Bending Test Till Failure To Calculate Fracture Toughness. Data Presented As Mean And Standard Deviation (SD). Kolmogorov?Smirnov Test Used For Test Of Normality. Two-way ANOVA Used To Compare Between Groups And Subgroup Followed By Pairwise Comparison With Bonferroni Correction (�=0.05).

Results: Descriptive Statistics Showed Significant Difference Detected Between The Mean Values Of Both Type Of Ceramic. Vita Enamic Showed Higher Mean Surface Roughness (Ra) (?m). For Method Of Aging, Thermocycling (Tc) Group Showed The Grates Effect On Mean Surface Roughness (Ra) Followed By (Alk/Tc) Group. (N/Tc) Shows The Least Values Of Mean Surface Roughness (Ra). Descriptive Statistics Showed Significant Difference Detected Between The Mean Values Of Both Type Of Ceramic. IPS E.max CAD Shows Higher Mean Fracture Toughness (KIC) MPa (m1/2) Than Vita Enamic. For Method Of Aging, Thermocycling (Tc) Group Shows The Grates Effect On Mean Fracture Toughness (KIC) Followed By Other Three Groups With No Significant Difference Between The Three Of Them. Conclusion: Vita Enamic Showed Higher Surface Roughness Than IPS E.max CAD After Subjecting To Aging. IPS E.max CAD Showed Higher Fracture Toughness Than Vita Enamic After Subjecting To Aging.