Influence of dehydration on strain pattern of human and bovine teeth: in vitro study / Influência da desidratação no padrão de deformação de dentes humanos e bovinos: estudo in vitro

RESUMO

The aim of this study was to measure the effect of the elapsed time on micro-strain of dental structure by strain gauge test of human and bovine teeth. Ten standardized bovine incisors and ten standardized human premolars were obtained. To measure the strain it was fixed one strain gauge on the buccal of each sample and it was also performed a compression test on each of dehydration times T0 immediately after removal from moisture; T5 after dehydration in room temperature (23 ± 1oC) for 5 minutes; T15 dehydration for 15 minutes; T45 dehydration for 45 minutes; T120 dehydration for 120 minutes; T24 dehydration for 24 hours; T24Re dehydration for 24 hours and rehydration for 24 hours in distilled water. The results were statistically analyzed by using one-way ANOVA and Tukey’s test (p < 0.05). Mean and standard deviation values in micro-Strain (μS) of human teeth were T0 56.7 ± 28.5 a; T5 56.9 ± 43.7 a; T15 40.2 ± 29.7 ab; T45 41.2 ± 22.1 ab; T120 32.2 ± 22.5 ab; T24 22.6 ± 21.7 b; T24Re 38.5 ± 12.9 ab, and bovine teeth were T0 47.5 ± 15.6 a; T5 39.2 ± 12.5ab; T15 34.2 ± 11.5 abc; T45 29.0 ± 7.9 bc; T120 25.3 ± 10.5 bc; T24 22.6 ± 10.2 bc; T24Re 29.9 ± 13.2 bc. The μS values were decreased with increasing of the dehydration time for both teeth groups. It can be concluded that dehydration caused strain decreasing being necessary to keep the samples hydrated during strain gauge tests.