[Effect of smear layer on the retention of custom made posts luted with two different cements]

ABSTRACT

Post retention has a considerable effect on restorative treatments and is influenced by various factors. The purpose of this study was to evaluate the effect of dentinal smear layer on the retention of custom-made posts luted with composite resin and zinc phosphate cements. Forty single-rooted lower premolars were decoronated, filed and filled with gutta-percha and divided into 4 equal groups. Post spaces were prepared to a length of 8 mm. Direct post patterns were made with acrylic resin and castings were fabricated using Ni-cr alloy. In Groups A and C, the post spaces were rinsed with 2 ml of 0.9% normal saline. The specimens in Groups B and D were rinsed with 1 ml of 17% EDTA followed by 1 ml of 5.25% Naocl and 10 ml distilled water. After drying, ZPC [Dentsply] was used for cementation in groups A and B. The samples in Groups C and D were luted with Panavia F[2.0]. Retention was measured on a Universal Testing Machine at 0.5 m/min. Data were subjected to statistical analysis using ANOVA. The mean amount of retention was 19.66 +/- 1.98 kg, 19.72 +/- 2.08 kg, 20.99 +/- 2.08 kg and 22.17 +/- 3.66 kg in groups A, B, C and D, respectively. There was no significant difference between the groups, but the mean value was highest in group D. The use of resin cement provided greater retention for custom-made posts compared to ZPC. Removing dentinal smear layer did not significantly affect the retention of custom-made posts cemented with ZPC or Panavia F[2.0]