The effects of different acid porcelain surface treatments on composite - porcelain shear bond strength

A. Mohmmed, Saifalarab; A. Al-Taie, Lamis

	The effects of different acid porcelain surface treatments on composite - porcelain shear bond strength
Journal of baghdad college of dentistry
Article 1, Volume 22, Issue 4, 2010, Pages 22-27
Authors
Saifalarab A. Mohmmed; Lamis A. Al-Taie
Abstract
ABSTRACTBackground: A number of systems have been developed to facilitate bonding of composites to porcelain, surfaceconditioning methods and agents accompanied with the use of silane coupling agent have resulted in improvedbond strength. This study was formulated to evaluate the effect of 37% phosphoric acid surface treatment incomparison to 1%,5%,and 10% hydrofluoric acid on bond strength of resin composite to porcelain.Material and Methods: Specimen preparation was divided in to two phases: fabrication of metal disks (8mmdiameter and 4mm thickness) and ceramic veneering. The metal specimens were obtained using lost waxtechnique. Thirty two ceramic fused to metal specimens were prepared, sandblasted with 50 μm aluminum oxide,and divided in to four groups of 8 samples: Group I: Etching with 1% hydrofluoric acid solution for 2 minutes .Group II:Etching with 5% hydrofluoric acid solution for 2 minutes. Group III: Etching with 10% hydrofluoric acid solution for 2minutes. Group IV: Etching with 37% phosphoric acid gel for 15 seconds. Monobond-s, Heliobond, Resin composite(Tetric Evo Ceram, Ceramic repair ,Vivadent /Ivoclar.Schaan/ Liechtenstein)were applied to each specimenaccording to manufacturer's instruction with the use of a plastic transparent split mold (4mm diameter and 4mmheight ) especially designed for this purpose, specimens were stored in 37 ºC in distilled water for 24 hours beforebeing thermocycled between 5ºC and 55 ºC for 100 cycles .Shear bond strength was determined by a universaltesting machine(Zwick 1454 ) at a cross head speed 5 mm/minutes .One way ANOVA test and LSD test were used toanalyze the bond strength.Results: Mean shear bond strength values for the tested groups were 21.25±2.67 for group I, 23.47± 1.24 for group II,23.68 ± 2 for group III, and 21.01 ± 2.16 for group IV. One way ANOVA test showed significant differences among thetested groups. LSD test revealed that specimens treated with 5%,and 10% conc. hydrofluoric acid(group II, andgroup III) were significantly higher than those treated with 1% hydrofluoric acid, and 37% phosphoric acid (group I,and groupIV),while there was no significant difference between group II, and group III, also between group I, andgroupIV.Conclusions: Surface preparation of the ceramic with 10% hydrofluoric acid for two minutes recorded the highestbond strength with the composite, most of specimens treated with hydrofluoric acid exhibited cohesive failure withinporcelain.Key words: Ceramic repair, Tetric Evo Ceram, hydrofluoric acid, shear bond. (J Bagh Coll Dentistry 2010;22(4):22-27).

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