Effect of thermocycling on shear bond strength and mode of failure of ceramic orthodontic brackets bonded to different porcelain restorations.
10.4041/kjod.2009.39.4.225
- Author:
Sang Wook KANG
1
;
Woo Sung SON
;
Soo Byung PARK
;
Seong Sik KIM
Author Information
1. Department of Orthodontics, School of Dentistry, Pusan National University, Korea. wsson@pusan.ac.kr
- Publication Type:Original Article ; Randomized Controlled Trial
- Keywords:
Thermocycling;
Ceramic bracket;
Shear bond strength
- MeSH:
Adhesives;
Ceramics;
Collodion;
Dental Porcelain;
Orthodontic Brackets
- From:Korean Journal of Orthodontics
2009;39(4):225-233
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
OBJECTIVE: The purpose of this study was to investigate the effect of thermocycling and type of porcelain restoration on shear bond strength (SBS) and mode of failure of monocrystalline ceramic brackets. METHODS: A total of 60 porcelain discs were made and divided into three equal groups as follows: Ceramco 3, IPS Empress II, Zi-ceram/Vintage ZR. ceramic brackets were bonded to the prepared porcelain surfaces in the same manner. Each group was divided randomly into two subgroups: thermocycled group and non-thermocycled group (control). All samples were tested in shear mode on an universal testing machine. RESULTS: SBS of the non-thermocycled group was clinically acceptable (Ceramco 3: 7.06 +/- 1.76 MPa, IPS Empress II: 7.55 +/- 2.38 MPa, Zi-ceram/Vintage ZR: 7.19 +/- 1.38 MPa). But, SBS of the thermocycled group was significantly reduced (Ceramco 3: 4.88 +/- 1.00 MPa, IPS Empress II: 5.46 +/- 1.35 MPa, Zi-ceram/Vintage ZR: 4.84 +/- 1.01 MPa, p < 0.05). There was no difference between the shear bond strength by type of porcelain restoration. All bonding failure occurred between bracket base and adhesive, except for 2 samples. CONCLUSIONS: The results of this study suggest that the type of porcelain restoration did not affect SBS, but thermocycling weakened SBS. Therefore, the effect of thermocycling should be considered when using ceramic brackets in practice.
