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| Post- Or Pin-Retained Core Restorations With Adhesive Materials In Vitro |
| G. M. Lösche*, S. M. Sabri, J.-F. Roulet |
| (Department Of Operative And Preventive Dentistry, Charité, Humboldt University Of Berlin, Germany) |
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For severely compromised teeth cast gold post and cores or pin retained amalgam cores are regarded as the restoration of choice to provide retention for a crown. The question is how adhesive materials perform with these retentive devices.
The crowns of 90 extracted single rooted premolars were removed and the teeth divided into 9 groups (n=10). 50 teeth were root canal treated and a post canal prepared using the Parapost system. Cores were fabricated with composite (Clearfil Core), Compomer (F 2000), RM GIC (Vitremer), amalgam (Permite) or cast gold (Pontor MPF). In the remaining 40 teeth 4 TMS pins were placed as retention for the plastic core materials. After crown preparation with 1.5 mm ferule gold crowns were fabricated and cemented. After water storage the restorations were tested in a servo-hydraulic mechanical testing machine (Instron 8500) using a stepwise, dynamic loading procedure with a frequency of 2 Hz, initially varying between 1 N and 100 N for 500 cycles. The load was incremented by 100 N and 500 cycles until failure occurred. The maximum energy-index was calculated (E = L1 x n + L2 x n + ... + Lmax x n failure (L = load; n = number of cycles). Results were statistically analyzed using non parametric tests (confidence level p = 0.05). No significant differences were found between the materials used (Kruskal Wallis Test). The Mann Whitney U Test revealed a significant difference of post vs. pin retention for amalgam cores.
| Material |
Gold |
F 2000 |
Vitremer |
Vitremer |
Permite |
Clearfil |
Clearfil |
F 2000 |
Permite |
| Retention |
Post |
Post |
4 Pins |
Post |
Post |
Post |
4 Pins |
4 Pins |
4 Pins |
| Mean ( x 10³) |
1860.5 |
1643.7 |
1569.9 |
1537.3 |
1514.2 |
1442.7 |
1407.1 |
1331.1 |
951.8 |
| Std. Dev |
873.4 |
944.2 |
1051.8 |
611.8 |
545.9 |
401.1 |
357.8 |
702.2 |
434.7 |
Though no material/retention combination was statistically identified as the system of choice, lower standard variations indicate more predictable results.
Materials used were supplied at no charge by their manufactures / distributors. The study was supported by the University Research Fund / Charité 99 - 159.
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