The purpose of this study was to examine the effect of acid-base surface treatment on the fracture resistance, which is one of main mechanical property, of zirconia restoration in order to improve the bonding characterization between zirconia core and ceramic veneer in bi-layered all ceramic restoration system. 10% hydrofluoric acid (HF) and 1 M sodium hydroxide (NaOH) were used as acid and base chemical solutions for surface treatment, respectively. Fracture-resistance tests were performed to investigate the effects of acid and liner treatment on the improvement of the bonding strength between veneer ceramics and zirconia. Specimens were divided into five groups (n = 4) according to the type of surface treatment: (1) Group A, no treatment (control); (2) Group B, liner treatment; (3) Group C, 10% HF etching for 60 s; (4) Group D, 10% HF etching for 60 s and liner treatment. All results of fracture resistance test showed that there were no significant differences between surface treatment types. Failure mode observation indicated that most specimens of Cerasys, Zmatch, and ICE groups showed cohesive failure mode regardless of the method of surface treatment. From the results of study, the short (1 min) treatment of zirconia in HF solution is supposed to be suitable for improving bond strength of zirconia restoration, but long (more than 30 min) treatment of zirconia in HF solution is expected to deteriorate the zirconia structure. Also, several factors such as liner and acid treatment, which improve the fracture resistance of zirconia restoration, seemed to depend on the type of zirconia materials.

1 정수하, "화학처리가 지르코니아와 비니어 세라믹의 결합강도에 미치는 영향" 대한치과재료학회 39 (39): 269-276, 2012

2 Swain MV, "Unstable cracking (chipping) of veneering porcelain on all-ceramic dental crowns and fixed partial dentures" 5 (5): 1668-1677, 2009

3 Denry I, "State of the art of zirconia for dental applications" 24 (24): 29-307, 2008

4 Craig RG., "Restorative dental materials" CV Mosby 65-, 1989

5 Blatz MB, "Resin-ceramic bonding : a review of the literature" 89 (89): 268-274, 2003

6 Kokubo T, "Novel bioactive materials with different mechanical properties" 24 (24): 2161-2175, 2003

7 Aboushelib MN, "Microtensile bond strength of different components of core veneered all-ceramic restorations. Part II: Zirconia veneering ceramics" 22 (22): 857-863, 2006

8 Aboushelib MN, "Microtensile bond strength of different components of core veneered all-ceramic restorations" 21 (21): 984-991, 2005

9 Lawn BR, "Materials design in the performance of all-ceramic crowns" 25 (25): 2885-2892, 2004

10 Blatz MB, "Long-term clinical success of all-ceramic posterior restorations" 33 (33): 415-426, 2002

11 Galoppini E, "Linkers of anchoring sensitizers to semiconductor nano-particles" 248 : 1283-1297, 2004

12 Wedler G, "Lehrbuch Der Physikalischen Chemie" VCH-wiley 2004

13 Aboushelib MN, "Innovations in bonding to zirconia-based materials. Part II: Focusing on chemical interactions" 25 (25): 989-993, 2009

14 Aboushelib MN, "Innovations in bonding to zirconia based materials : Part I" 24 (24): 1268-1272, 2008

15 Blatz MB, "Influence of surface treatment and simulated aging on bond strengths of luting agents to zirconia" 38 (38): 745-753, 2007

16 Blatz MB, "In vitro evaluation of long-term bonding of Porcera all-ceram alumina restorations with modified resin luting cement" 89 (89): 381-387, 2003

17 "ISO 9693; Metal-ceramic dental restorative system"

18 Lohbauer U, "Hydroxylation of dental zirconia surfaces : characterization and bonding potential" 87 (87): 461-467, 2008

19 Zarone F, "From porcelainfused-to-metal to zirconia : clinical an experimental considerations" 27 (27): 83-96, 2011

20 Albakry M, "Fracture toughness and hardness evaluation of three pressable all-ceramic dental materials" 31 (31): 181-188, 2003

21 Strub JR, "Fracture strength of 5different all-ceramic crown systems" 11 (11): 602-609, 1998

22 Zahran M, "Fracture strength and fatigue resistanc of allceramic molar crowns manufactured with CAD/CAM technology" 17 (17): 370-377, 2008

23 Fischer J, "Flexural strength of veneering ceramic for zirconia" 36 : 316-321, 2008

24 Touzi H, "Elaboration and electrical characterization of silicone-based anionexchage materials" 48 : 1347-1354, 2006

25 Atsu SS, "Effect of zirconium-oxide ceramic surface treatments on the bond strength to adhesive resin" 95 (95): 430-436, 2006

26 Canay Ş, "Effect of different acid treatments on a porcelain surface 1" 28 (28): 95-101, 2001

27 Piascik JR, "Development of a novel surface modification for improved bonding to zirconia" 27 (27): 99-105, 2011

28 Sjogren G, "Cytotoxicity of dental alloys, metals, and ceramics assesse by millipore filter, agar overlay, and MTT tests" 84 (84): 229-236, 2000

29 Rosenstiel SF, "Contemporary Fixed Prosthodontics" Mosby 262-271, 2001

30 Drummond JL, "Ceramic Behavior Under Different Environmental and Loading Conditions. Dental Materials In Vivo: Aging and Related Phenomena" Quintessence Int 35-45, 2003

31 Fischer H, "Bioactivation of inert alumina ceramics by hydroxylation" 26 (26): 6151-6157, 2005

32 Uchida M, "Apatite-forming ability of a zirconia/alumina nano-composite induced by chemical treatment" 60 (60): 277-282, 2002