The influence of some dentin primers on calcium hydroxide lining cement.

Unlabelled: Dentin primer is applied as a routine procedure prior to bonding to improve the sealing properties of direct polymerizing resins. Some primers contain acetone or alcohol that may affect the properties of calcium hydroxide liner which is placed as a direct or indirect pulp cap. If calcium hydroxide is softened or smeared over the cavity walls, the bonding will be impaired. Therefore, if this occurs, the cement must be removed, the walls must be cleansed, and the procedure must be repeated with careful application of dentin primer.

Objective: The purpose of this study was to determine the wear and compressive strength of a calcium hydroxide liner after exposure to different kinds of dentin primers for different periods of time.

Methods: The calcium hydroxide used in this study was Dycal. It was mixed according to the manufacturer's instructions and placed in plastic rings of 0.5 mm x 5 mm and allowed to set at 37 degrees C for 15 min under 500 gm load. To determine erosion, the height for each sample before and after application of primers was recorded using a Digital Height Measuring Instrument "Digmar" 817. Compressive strength specimens were also prepared.

Results: Calcium hydroxide treated with Optibond (alcohol based) or Syntac (acetone based) for 1 min or 5 min had the highest erosion values and the lowest compressive strength values. Gluma CPs (water based primer) had the least effect on calcium hydroxide values.