Various restorative treatment options for enodontically treated posterior teeth

The aim of the present study is to evaluate the fracture resistance of endodontically treated teeth restored with five different restorative materials as well as clinical performance and success of a material with highest test results conducted in vitro, comparing to frequently used composite resin in practice. For fracture resistance in vitro study, hundred and forty extracted human molar teeth was used. After root canal treatment cavities were prepared as class II MOD. To restore the cavities five different techniques were used: Direct composite resin restoration (DK), bi-directional fiber reinforced composite resin restoration (OFGK), short fiber reinforced composite resin restoration (KFGK), flowable bulk-fill composite resin (ABFK), and indirect composite resin restoration (IK). After endodontic treatment and preparation of MOD cavities, specimens with no restoration were used as negative control and intact molar teeth were used as positive control. One-way ANOVA statistical analysis revealed that the fracture resistance was significantly affected by the restoration type. The test results of fracture resistance showed values between 1687 N-2228 N (p < 0.05). For in vitro evaluation of flexural strength of five different materials, three-point bending test specimens (n=15) were made from each tested composite resin using a mold according to ISO 4049 standards counting a total of 75 specimens. The test results of flexural strength showed values between 140-184MPa, modulus of elasticity between 6.33-18.89 GPa (p < 0.05). After evaluation of flexural strength and modulus elasticity, the group with the highest test results (KFGK) was selected for clinical trial. A frequently used posterior composite resin was selected as a control group. 30 patients were selected and 15 restorations per group were performed. Statistical evaluation showed that there was no significant difference between groups at the beginning and 12 months. Secondary caries, surface texture showed no change while marginal integrity, marginal discoloration, anatomic form showed slight differences not statistically significant (p < 0.05).