Radwa Ibrahim El-Tahwi, Enas Fathelbab Abdelhalim And Shams Waaz Amgad .,

ABSTRACT

Objectives: The Purpose Of This Study Was To Assess The Retention Strength Of Resin Nano Ceramics And Polyetheretherketone After Different Surface Treatments.

Materials & Methods: Forty Human Upper Central Teeth Were Prepared For Crowns And Divided Into Two Main Groups According To The Type Of Material Used; Twenty For Lava Ultimate And Twenty For Bio HPP. Each Group Was Further Divided Into Four Subgroups; 1) No Treatment, 2) Airborne-particle Abrasion With 50 ?m Alumina, 3) Airborne-particle Abrasion With110 ?m Alumina, And 4) 5% HF Acid Etching For 20 Sec. Thereafter, Crown Specimens Were Luted To Dentin Abutments Using Self-adhesive Resin Cement RelyX U200 And Stored In Water For 60 Days. All Specimens Were Thermocycled (5000 Cycles, 5�C To 55�C). Retention Strength Of Crowns Were Measured Using Pull-off Test In A Universal Testing Machine. Subsequently, Failure Types Were Determined Using SEM. Data Were Analyzed With 2-way And 1-way ANOVA Followed By Tukey?s Post Hoc Test.

Results: There Was No Significant Difference Between Retention Strength The Two Tested Materials. Air-abrasion With 50 ?m Alumina Recorded The Highest Mean Values For Maximum Pull Out Load (N) Followed By Air-abrasion With 110 ?m Alumina, HF Acid Etching, And Control Group, Respectively.

Conclusions: Airborne-particle Abrasion With 50 ?m Alumina Before Cementation Enhances Retention Strength Of Both RNC And PEEK Crowns. Adhesive Failure Mode At The Cement-dentin Interphase And Cohesive Within The Ceramic Material Denoted Adequate Bonding Between The Tested Materials And Luting Agent.