This study aimed to determine the influence of post space preparation with peeso reamers on the marginal integrity of a glass Ionomer cement (GIC) root end restoration. Thirty maxillary anterior teeth were disinfected, decoronated to obtain 16mm root lengths, cleaned shaped and obturated rising cold lateral compaction with AH Plus as the scaler: Teeth were divided into three groups of ten teeth each. In Group 1, the post space preparation was done first, followed by GIC retrograde restoration. In Group II , the GIC retrograde restoration was placed first, allowed to set completely and then followed by post space preparation. Group Ill served as the positive control. Teeth were coated with trail varnish and immersed in Rhodamine B dye for 4(s hours and microleakage assessed under 20X magnification rising a sterecomicroscope. Mean leakage of 1211.36 Um was recorded for Group I, 2088.63 Um for Group II and a complete leakage of 3000 Um far Group III. Significant difference existed between Group I & II (p<0.05) and a vets highly significant difference between Group I &III and Group Il & III. It was concluded that after complete setting of GIC, the vibrational energy of post space preparation is capable of disrupting its seal, when it is used for root end restoration.

This in vitro study was carried out to evaluate the quality of Resin - Dentin Interface and also to determine the shear bond strength of three different bonding systems. The systems used was Gluma Comfort Bond, Adhese and Prompt. L. Pop. The Resin - Dentin Interface was evaluated under scanning electron microscope, which showed variation in hybridization and resin tag formation between the groups. The specimens were also subjected to shear bond strength in universal testing machine. The mean bond strength of Gluma Comfort Bond (Group 1) = 18.81 MPa, Adhese (Group 2) = 23 MPa and Prompt L Pop (Group 3) = 10.83 MPa. The results were statistically analyzed using Anova and Students-t- test. 11 was found that the bond strength value of group 2 were significantly higher than group 1 and group 3. The present study concludes that it is the uniformity and density of the hybrid layer which is more important than the thickness for the integrity of the restorative - tooth interface.

This study evaluates how three types of bilayered restorations behave in a modified abfractive lesion when subjected to a tensile load using a finite element model analysis. Mandibular premolars were used and an oblique load of 100 N was applied at an angle of 45 degrees to the long axis of the tooth. A wedge shaped lesion was then created on the buccal aspect of the tooth in the cervical region. It was then subjected to the same loading conditions. Then the internal line angle was rounded off and the tooth was subjected to the same loading conditions. This region then restored in four ways and subjected to the same loading conditions. The cavities were restored with a hybrid composite alone or with bilayered restorations. The stress analysis was performed on this tooth using the ANSYS solver The results were, stress was more in teeth with cervical lesions. Among the various restorations used it was seen that a combination of Z100 and Silux Plus performed the best. In conclusion it is seen that roundening of line angles is mandatory in wedge shaped cervical lesions. A bilayered restoration is to be used in which, the deeper layer has a low modulus of elasticity and a high ultimate tensile strength.