Omaima S.A. Tawfik, Cherif A. Mohsen And Shams W. Amgad,

ABSTRACT
Objective: The Aim Of This Study Is To Compare Microleakage And Marginal Adaptation Of Three Ceramic Types (zirconium Ceramics, Lithium Disilicate And Hybrid Ceramics) Of Two Designs Of Inlay-Retained Fixed Partial Dentures (IRFPDs) .Methods: Sixty Inlay Retained Fixedpartial Dentures Were Constructed, Samples Were Divided Into Two Groups According To Type Of Inlay Preparation Design, Group B (no=30 Inlay Retained Fixedpartial Dentures) Was Designed In Box-shape Design, Group S (no=30 Inlay Retained Fixedpartial Dentures) Was Designed In Slice Shape Design. Further, Each Group Was Subdivided Into Three Subgroups According To Ceramic Material Used Into, Group Z (no=10 Inlay-retained Fixedpartial Dentures) Fabricated From Zirconia Ceramic (Katana STML Zirconia), Group L (no=10 Inlay-retained Fixedpartial Dentures) Fabricated From Lithium Disilicate Ceramic (IPS E.max CAD), And Group B (no=10 Inlay-retained Fixedpartial Dentures) Fabricated From Bio-HPP Material (bre-CAM. BioHPP) , At The End Each 5 Samples From Each Subgroup Were Tested For Marginal Adaptation Microscopically On Each Sample Using A Computer-aided Stereomicroscope At 45x Magnification,and The Other 5 Samples Were Tested For Microleakage By The Solution Of 2% Methylene Blue Dye.

Results: For The Microleakage Test; According To The Different Materials Types The Results Showed That E-max Recorded The Highest Mean Value Of At 34.4 ?m Followed By Zirconia At 30.2 ?m, While The Lowest Was Peek At 22.1 ?m. Regarding The Preparation Designs The Results Showed That The Highest Mean Value Was For E-max At Slice Shaped Design At 34.4 ?m Followed By E-max At Box Shaped Design At 31.0 ?m While The Lowest Was Zirconia At Box Shaped Design At Zero (No Leakage). For The Marginal Adaptation Test; According To The Different Materials Types The Results Showed That The Highest Mean Value Was For Peek After Thermocycling At 68.5 ?m Followed By E-max After Thermocycling At 63.8 ?m While The Lowest Was For Peek Before Thermocycling At 34.3?m. Regarding The Preparation Designs They Showed That The Highest Mean Value Was Recorded With The Slice Shaped Design Of Peek After Thermocycling At 80.8 ?m Followed By Box-shaped Design Bio-HPP After Thermocycling 73?m While The Lowest Was Box Shaped Design Of Peek Before Thermocycling At 22.5?m. Conclusion: Microleakage And Marginal Adaptation Of Inlay Retained Fixedpartial Dentures Were Affected By The Material Type And Preparation Design. Marginal Adaptation Of The Inlay Retained FPDs Was Affected By The Material Type That IPS E-max Showed The Highest Marginal Gap Followed By Bio-HPP Then Zirconia. Thermocycline Significantly Afect Both Marginal Adaptation And Microleakage.Clinical Recommendation: Further Investigations Should Be Done For Microleakage And Marginal Adaptation Of Inlay Retained Fixed Bridge