9 �� 3.2 mg, 23.58��4.8 mg, 17.5�� 3.3 mg, 17.1��4.1 mg. The ceramic inlays were placed on the prepared teeth with light finger Tivantinib pressure. 21 Photo-polymerization was performed with the light-polymerizing unit (Hilux Ultra Curing Unit, Benlioglu Dental Inc., Ankara, Turkiye) at 550 mW/cm2 (with a light tip to specimen distance of 0 mm) for 40 seconds for occlusal, lingual, and buccal surfaces. After undergoing light polymerization, excessed cements were removed by using 15 diamond bur (852EF.314.014, Komet Dental, Gmungen, Austria) and cleaned with a rubber cup (9402204030, Komet Dental, Gmungen, Austria) on a slow-speed hand piece for 15 s. The chemical composition is listed in Table 1. Table 1 The chemical composition of resin cements.
All specimens were immersed immediately in light proof glass bottles containing 75% ethanol, 25% deionized water15,22 after polymerization of resin cements and stored at 37��C. The extracts were taken off for every time interval without refreshing (10 minutes., 1 hour, 24 hours, 3 days, 7 days, 14 days, 21 days) from bottles which have immersed specimens. Residual monomer (TEG-DMA) which eluted from resin cement in ethanol solution were analysed with HPLC. HPLC analysis The analysis of extracts from the resin cement as well as reference solutions of the monomers in water/acetonitrile (25:75) was carried out by HPLC (Agilent Technologies, USA) with the following conditions: Column: steel column (Waters Corporation, Milford Massachusetts, USA), 250 mm in length, 4.6 mm in diameter, and particle size of 5 ��m.
Mobile phase: CH3CN 75%/H2O 25% (Acetonitrile) Flow speed: 1 mL/min. Detection: UV: 208 nm for TEGDMA Injection: 10 ��L loop at constant room temperature All measurements were performed 3 times for each of the extracts. Calibration curves were made relating eluted peak area to known concentrations of TEGDMA. The elution time for TEGDMA was 3.446 min. The concentrations of the leaching monomers from resin matrix were calculated by using the coefficients obtained by a linear regression analysis of the results from the Standard series. Linear calibration equation for TEGDMA is shown in Table 2. Table 2 Linear calibration equations for TEGDMA. The data of eluted residual monomer from resin cement in time intervals were analysed by two way analysis of variance (ANOVA) (residual cements and time intervals) and Tukey HSD test.
The data of residual monomers eluted in different time intervals were analyzed by one way ANOVA and Tukey HSD tests. RESULTS The two way ANOVA indicated that amount of residual monomer values vary according to the materials (TEGDMA) (P<.01) and time intervals (10 min, 1 hour, 24 hours, 72 hours, 7 days, 14 days, 21 days) (P<.01) (Table 3). Dacomitinib Mean and standard deviations of groups are presented in Table 4. Table 3 Two way analysis of variance indicates the amount of residual monomer values vary according to the materials.