Gibt es eine ideale Restauration nach endodontischer Behandlung?

Objective and purpose A root canal treatment is a common therapy in the dental practice. This is usually the only way to preserve the tooth in the long-term. The success rate of endodontic treatment has increased in the last years. There is evidence for 10-year survival rates of between 85 and 93%. The success and the patients satisfaction can be attributed to effective root canal treatment and to the appropriate decision regarding post-endodontic therapy. Due to access cavity preparation tooth suffers considerable loss of sound hard tissue. The fracture risk of the remaining hard tooth tissue is dramatically increased. In the worst case, the tooth has to be extracted after vertical fracture. Post-endodontic restorations aim to stabilize the remaining hard tooth tissue in order to complete the biomechanical stability of the tooth and to eliminate bacterial recontamination. The question which restoration is the best option for root canal treated teeth is still open to debate. Dentists are uncertain in choosing a definitive therapy and patients demand esthetic restorations. More and more scientific research is being done with regard to ceramic and resin composite materials. Materials und Methods 96 freshly extracted human third molars (n=8) were stored in destilled water. 11 experimental series and one control group were investigated. After the access cavity preparation, root canals were filled and the teeth were restored with following materials: Resin composite direct (Tetric EvoCeram Bulk Fill, Ivoclar Vivadent), ceramic indirect (IPS Empress, Ivoclar Vivadent; e.max CAD, Ivoclar Vivadent; Celtra Duo, Dentsply DeTrey), Hybrid Nano Ceramic (Lava Ultimate, 3M Espe) und cast gold (Degussa). Subcriitical loading was performed using a chewing simulator. Chewing simulation was carried out with 1,200,000 cycles at a force of 50 N and additional 300.000 thermocycles (5°C/55°C). Consequently the teeth were loaded in a universal testing machine until catastrophic fracture. Results The statistical analysis was performed using the Windows program SPSS 15.0 (SPSS, Chicago, USA). For the analysis I used the Kolmogorov-Smirnov-test, the Wilcoxon matched-pairs-signed-ranks-test and the Kruskal-Wallis-test. The highest fracture resistance was measured for restorations with cast gold partial crowns and in the control group (p<0.05). The lowest results were measured with IPS Empress inlays, IPS Empress partial crowns, e.max CAD inlays and Celtra Duo inlays. It was remarkable that the values of the overlay restorations were significantly higher than the inlay restorations (p<0.05). Only the IPS Empress inlays and IPS Empress partial crowns showed no significant difference (p<0.05). Significance The results of this study exhibited significant differences between the fracture resistance in inlay and partial crown restorations. Except for IPS Empress restorations, partial crowns showed higher results than inlays. The highest fracture strengths were measured for gold partial crowns and the control group, respectively. Based on the current results, the post-endodontic restoration with partial crowns is the best way for post-endodontic restoration when it comes to fracture resistance. By comparing the groups, the significantly higher values of gold partial crowns and the control group are noticeable. All in all the present results corresponded to the empirical evidence.