Acidity of glass ionomer cements during setting and its relation to pulp sensitivity

Recent findings regarding pulp sensitivity to luting glass ionomer cements have aroused controversy as to the cause of the problem. Contributing factors may include chemical irritation from the material and leakage. The pH changes during setting were determined for three glass ionomer cements, a zinc phosphate cement, and a polycarboxylate cement. The data showed that the glass ionomer luting cements may show lower pH values for longer times than the other cements. This initial acidity, involving a prolonged period at pH below 3, coupled with cytotoxicity of other ingredients, may lead to damaging effects on the pulp when manipulation of the material and tooth preparation and cementation procedures are less than ideal.