Effect of a new conditioning agent on dentin

The effect of varying the duration of application of the conditioner for light-cured Zionomer was studied. The conditioner is a solution of oxalic acid and aluminum nitrate in a weak mineral acid and has a pH of 2.06. Recently extracted non-carious human premolars were sectioned horizontally 300 microns below the amelodentinal junction and then lightly ground with a high-speed diamond bur under copious water-spray to produce a smear layer. Each was then sectioned vertically into three and all the specimens were either treated with the Zionomer Conditioner for 5, 10, 20 or 30 seconds, or with distilled water as a control. All the specimens were examined in a scanning electron microscope at x1000 and photomicrographs taken which were then assessed, independently, by the authors. The results revealed that application of Zionomer Conditioner for as little as 5 seconds was sufficient to remove most of the smear layer. There was complete removal of the surface smear layer in specimens treated for 10 seconds or more. Either a 20 second or a 30 second application removed the smear layer completely and could also widen the exposed tubule orifices.