Influence of pretreating radicular dentin with different polyacrylic acids and isopropanol on the retention of posts.

Statement Of Problem: The optimal pretreatment of radicular dentin before cementing a post with glass ionomer cement is unclear.

Purpose: The purpose of this in vitro study was to evaluate the retention of prefabricated tapered titanium posts to endodontically treated teeth after applying different pretreatment protocols on the radicular dentin.

Material And Methods: The coronal part of 32 single-rooted human teeth was removed 1-mm coronally to the cemento-enamel junction. All specimens received endodontic treatment, and the root canals were prepared with an instrument to a depth of 10 mm to receive a titanium post. The dentin walls of each specimen were roughened with a hand-held diamond cutting instrument. The specimens were randomly divided according to the surface treatments into 4 groups (n=8): KW: etched with 20% to 30% polyacrylic acid (PAA) (Ketac Conditioner) and rinsed with water; KWI: etched with 20% to 30% PAA, rinsed with water and 70% isopropanol; DW: etched with 30% to 50% PAA (Durelon Liquid) and rinsed with water; DWI: etched with 30% to 50% PAA, rinsed with water and 70% isopropanol. The prefabricated titanium posts were airborne-particle abraded and cemented with glass ionomer cement. The specimens were fixed in custom-made brass cylindrical holders with autopolymerizing acrylic resin with the holder parallel to the long axis of the post. All specimens were stored in water for 3 days at 37 °C. Retention was evaluated using a tensile test with a universal testing machine (Zwick Z010) at a crosshead speed of 2 mm/min. Data were statistically analyzed with a 1-way ANOVA, followed by the Tukey post hoc test for pairwise comparisons between groups (α=.05).

Results: Mean ±standard deviation retention values ranged from 201.8 ±55.5 N (KW) to 328.1 ±70.9 N (DWI). Groups DWI and KWI (316 ±58.3 N) showed statistically higher retention values than group KW (P<.05) but did not significantly differ from retention values obtained in group DW (P>.05).

Conclusions: An additional final rinse with isopropanol after using PAA increased the retention of the post significantly for all groups. Although group DWI achieved the highest retention values, pretreatment of radicular dentin as in group KWI may also be considered.