In-vitro investigation to evaluate the flexural bond strengths of three commercially available ultra low fusing ceramic systems to Grade II Titanium.

BACKGROUND This in-vitro investigation was designed to compare the flexural bond strengths of three commercially available ultra low fusing ceramic systems to Grade II Titanium and evaluate the type of bond failure through Scanning Electron Microscopy (SEM) and Energy Dispersion X ray Spectrum (EDS). MATERIALS & METHODS Sixty patterns of auto polymerizing resin of dimensions 25.1 mm X 3.1mm X 0.6mm each were fabricated from a stainless steel die. Titanium casting for all the samples was done in a Titanium casting machine. Ten samples were allotted to each of three groups randomly. Ceramic build up was done step by step using the manufacturers' instructions. Flexural Bond strength tests for the samples were performed by using a 3-point bending test on a Universal testing machine in compliance with Deutsches Institut für Normung (DIN) 13.927 draft. After the tests were completed, three samples, one from each group were selected randomly for the subsequent Scanning Electronic Microscopy (SEM) studies to characterize the type and morphology of the fracture in representative specimens. RESULTS The maximum load to fracture the porcelain was recorded for each specimen. All the means of the three groups were compared by one-way Analysis of Variance (ANOVA) and it was found that Group I & Group III had significantly higher bond strength values as compared with the Group II (P< 0.001). All the 10 samples of Group I & III gave bond strength values above the standard values of 25 MPa. There was statistically significant difference in the bond strengths between Group I & Group III (t = 2.76 and P< 0.05), between Group I & II (t = 5.09 and P< 0.001) and between Group II & Group III (t = 13.28 and P< 0.001). SEM studies revealed occurrence of cohesive type fractures in the ceramic body of samples belonging to Groups I & III, while there was adhesive failure at ceramo-metal junction of samples belonging to Group II. EDS Analysis supported the findings of SEM studies. CONCLUSION All the three ceramic systems fared better than the minimal recommended values stated by ISO 9693:1999 of 25MPa of which Orotig TiKrom was rated the best with values of 54.69 MPa. Vita TitanKeramik ranked second with values of 45.12MPa and the least values were obtained with Noritake Ti-22 with values of 27.76. The bond failure was predominantly cohesive in nature in case of Vita TitanKeramik and Orotig TiKrom; whereas adhesive failure was noticed in case of Noritake Ti-22. How to cite this article: Mabrurkar V, Habbu N, Hashmi SW, Musani S, Joshi N. In-vitro investigation to evaluate the flexural bond strengths of three commercially available ultra low fusing ceramic systems to Grade II Titanium. J Int Oral Health 2013;5(5):101-7.