Composite bonding to IPS Empress and Cercon

Objectives: Determine whether similar repair approaches should be used for different ceramic materials. To perform such an evaluation, IPS Empress (IE)) and Cercon (CE) treated with for different bonding approaches were compared.

Methods: Seventy-two specimens each of IE and CE were fabricated, embedded and ground flat with sandpapers (240, 400 and 600 grits) until one surface was completely exposed and smooth. Each material received 3 different treatments: no treatment (P), sand blasting with 50 µm AL2O3 (SB), or acid etching with 9.6% hydrofluoric acid (AE). Each of these groups was divided into 4 subgroups of 6 specimen each. Each subgroup was bonded to composite cylinders using either silane and Optibond FL Adhesive(SO), 904 adhesive with Optibond FL Adhesive(ZR), Calibra and XP Bond(SXP), or Clearfil Ceramic Primer(CK) and stored 7 days in water at 37C before sheared tested.

Results: Comparing the two ceramics independant of surface treatment and adhesive system revealed that IE resulted in significantly (p<0.05) higher repair strength values than CE. Regarding the three surface treatments, there was no significant (p>0.05)difference between SB and AE treated surfaces, while repaired P surfaces were significantly weaker (p<0.05). Of the four adhesive systems, no significant (p>0.05) difference existed between SO, SXP and CK, while ZR was significantly (p<0.05) lower. However, significant (p<0.001) interactions existed between the different variables. The two highest values for IE were achieved with AE and SXP (37.4+/-11.2)MPa or AE and SO (36.1+/-2.8)MPa. The best result for reparing CE was SB and SXP (27.2+/-3.3)MPa, while the second best treatment was P and SXP 15.0+/5.4)MPa.

Conclusion: In order to repair a fractured or chipped all ceramic crown, one needs to know the composition of the core structure. In this study, the zirconia based material performed best by using sand blasting, while the IE material preformed best after hydrofluoric acid etching.