Abstract
Gypsum crystal growth on human dentin surface was investigated using a crystal growth agent composed of 4〜20% ammonium sulfate and 5〜60% acrylic acid aqueous admixtures.In the treatment with 4% ammonium sulfate which contains the concentration of acrylic acid from 5% to 60%, fine half-spherical aggregates of 25μm in diameter of needle-like crystals ware obtained from 35% acrylic acid and large ones from 30% acrylic acid. Using the crystal growth agent of 4% ammonium sulfate-35% acrylic acid aqueous admixture, the human dentin surface pretreated with sulfates of different cations was evaluated from crystal growth.All sulfates without 4% ZnSO4 formed half-spherical aggregates of needle-like crystals. Diameter of their half-spherical aggregates increased as follows; 4% Na2SO4< nonetreatment < saturated CaSO4・2H2O < 4% K2SO4 < 4% MgSO4 < 4% ZnSO4. The half-spherical aggregates from sulfates of Na+ and K+ (alkali metal) grew finer than those from sulfates of Ca2+ and M2+ (alkali-earth metal) and Zn2+ (zinc) and their area on dentin surface increased more with sulfates of alkali metal than with those of alkali-earth.
