[Effect of various storage methods on shear bond strength of enamel of bovine teeth]

PURPOSE：The purpose of this study was to evaluate the effect of various storage methods on shear bond strength of enamel of bovine teeth and find the storage condition that could preserve the similar bond strength as the freshly extracted teeth.

One hundred and thirty freshly extracted bovine teeth were divided into 13 groups. One was the reference group and 12 were the experimental group. Each group contained 10 teeth. Teeth in the reference group were operated on the same day as the teeth were extracted, while teeth in the experimental groups were stored in different methods (4% formaldehyde solution at 4 ℃, 23 ℃, 1% chloramine T at 4 ℃, 23 ℃, distilled water at 4 ℃, 23 ℃). After stored for 30 days and 90 days, the bovine teeth were taken out and then the shear bond strength was tested. The data were analyzed with SPSS 20.0 software package.

The bovine teeth stored in 4% formaldehyde and 1% chloramine T at 23 ℃ and in distilled water at 4 ℃ achieved similar bond strength as freshly extracted teeth at 30 days and 90 days, and the bond strength did not change over time. The bovine teeth stored in 4% formaldehyde solution and 1% chloramine T at 4 ℃ at 30 days had higher shear bond strength than freshly extracted bovine teeth, but over time the bond strength reduced and reached the similar level at 90 days. The bovine teeth stored in distilled water at 23 ℃ obtained similar bond strength as freshly extracted teeth at 30 days but over time the bond strength reduced until 90 days.

Bovine teeth stored in 4% formaldehyde solution and 1% chloramine T at 23 ℃ and in distilled water at 4 ℃ achieved similar bond strength as freshly extracted teeth and does not change over time. These three methods are recommended for storing bovine teeth.