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

Effect of smear layer on the retention of custom made posts luted with two different cements Dr. H. Sazgara*- Dr. K. Seyyedan ** - Dr. A.H. Majidi*** *Associate Professor of Fixed Prosthodontics Dept., Faculty of Dentistry, Shaheed Beheshti University of Medical Sciences.**Assistant Professor of Fixed Prosthodontics Dept., Faculty of Dentistry, Shaheed Beheshti University of Medical Sciences. ***Assistant Professor of Fixed Prosthodontics Dept., Faculty of Dentistry, Qazvin University of Medical Sciences. Background and Aim: 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. Materials and Methods: 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 F2.0. Retention was measured on a Universal Testing Machine at 0.5 m/min. Data were subjected to statistical analysis using ANOVA. Results: 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. Conclusion: 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 F2.0. Key words: Smear layer - Custom-made post - Resin cement - Zinc phosphate cement - Retention