Investigating the effect of applying oxalate potassium on human roots (dentin) permeability comparing with smear layer produced during instrumentation, by spectrophotometer

The aim of this study was to determine the effect of the artificial layer produced by oxalate potassium on permeability of human root's dentine comparing with the smear layer produced by root canal therapy. Seventy extracted mandibular premolars which had one root also the canal was direct without any resorption, decay nor advanced periodontal disease, were chosen. The end of the roots were completely sealed and no calcification nor breakage were observed in them. Samples were divided into four groups randomly: two test groups and two control groups. Each test group consisted of 30 samples and control groups contained 5 samples each. In order to measure permeability of dye through dentin, the spreading cabinet method was used and the amount of 2% methylen blue penetrated thorough the canal wall was calculated after 72 hours. Samples were evaluated by spectrophotometer with wave length of 640. In negative control group, no penetration was observed and also in the other three groups no statistical significant difference in dye permeability was observed. The greatest amount of permeability was in the absence of smear layer. Natural smear layers were second and artificial smear layer created by applying oxalate potassium was third. Therefore oxalate potassium can be applied in infectious canals after removal of smear layer which is full of micro-organisms and poisonous products in order to reduce dental tubule's penetration. However sufficient investigations should be conducted in-vivo regarding tissue biocompatibility and harmlessness of this compound.