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