STORAGE EFFECTS ON DENTIN PERMEABILITY AND SHEAR BOND STRENGTHS

The effects of duration of storage and selection of storage solution u pon dentin permeability and bond strength were studied over a period o f 8 d to 6 mon. Teeth were stored immediately after extraction in one of five commonly used solutions: 70% ethanol (E); 10% formalin (F); di stilled water (W); distilled water with thymol (WT); or phosphate-buff ered saline with thymol (ST). Permeability and lap shear bond strength measurements were evaluated in a repeated measures design (n = 20) af ter 8 d, 15 d and 6 mon. Dentin permeability varied with solution type and duration of storage as demonstrated by ANOVA, increasing for F, E and the water-based solutions, respectively. Saline storage resulted in large significant decreases in permeability after prolonged storage , suggesting changes in dentin. Bond strengths were unaffected by dura tion of storage or by solution type, except for saline. Thus, permeabi lity and bond strength values may be affected by storage conditions. T he results of this study indicate that saline, the most commonly used solution in dental materials research, may be unsuitable for use as a result of its effect on dentin permeability and bond strength.