Effect of tribochemical silica coating on the shear bond strength of rebonded monocrystalline ceramic brackets / 대한치과교정학회지

ABSTRACT

OBJECTIVE: The purpose of this study was to investigate the effect of tribochemical silica coating on the shear bond strength (SBS) of rebonded ceramic brackets using nano-filled flowable composite resin. METHODS: A total of 60 premolars were prepared and divided into 4 equal groups as follows: Tribochemical silica coating (TC) + Transbond XT (XT), TC + Transbond supreme LV (LV), Sandblast treatment (SA) + XT, SA + LV. Treated ceramic brackets were rebonded on the premolars using each adhesive. All samples were tested in shear mode on a universal testing machine. RESULTS: SBS of silica coated groups were high enough for clinical usage (TCLV: 10.82 +/- 1.82 MPa, TCXT: 11.50 +/- 1.72 MPa). But, SBS of the sandblast treated groups had significantly lower values than the tribochemical silica coated groups (SALV, 1.23 +/- 1.16 MPa; SAXT, 1.76 +/- 1.39 MPa; p< 0.05). There was no difference between the shear bond strength by type of adhesive. In the silica coated groups, 77% of the samples showed bonding failure in the adhesive. In the sandblast treated group, all bonding failures occurred at the bracket-adhesive interface. CONCLUSIONS: The result of this study suggest that newly introduced nano-filled flowable composite resin and tribochemical silica coating application on debonded ceramic bracket bases can produce appropriate bond strengths for orthodontic bonding.