To fabricate a cast metal restoration, the procedure requires meticulous care both in cavity preparation and in proper manipulation of dental materials. Also, there must be a devotion to perfection on the part of the dentist and the laboratory technician. The cast metal inlay is selected over an amalgam restoration when the higher strength of a casting alloy is needed or when the superior control of contours and contacts that the indirect procedure provides is desired. The cast metal onlay is the treatment of choice for the restoration of a tooth that has been greatly weakened by caries or by large, failing restorations but the facial and lingual tooth surfaces are relatively unaffected by disease or injury. For such weakened teeth the superior physical properties of a casting alloy are desirable to withstand occlusal loads placed on the restoration; also, the onlay can be designed to distribute occlusal loads over the tooth in a manner to decrease the chance of tooth fracture in the future. Moreover, conserving intact facial and lingual enamel (or cementum) is conducive to maintaining the health of contiguous soft tissues.

This study was performed on seuerntil-two freshly extracted first permanent mandibular molars. In half of the samples (thirty six) root canal treatment was done and access cavities were sealed with glass ionorner/ cement. In the other half cavities were prepared to a depth of 4 mm. Cavity designs used were class 1. class 11 arid tunnel preparation. In each group half of the samples were restored with composite and half of them with amalgam. Fracture resistance was calculated with the help of Instron Universal Tensile Testing machine. It was concluded that after endodontic treatment strength of the teeth to bear masticatory loads is reduced to almost half and composite can effectively reinforce as compared to amalgam.

Forty five mandibular molars were root canal treated in single visit therapy comparing three different sealers viz. Apexit (vivadent), lodoform & Resorcinol (resinifying therapy). All the treated teeth were examined clinically & radiologically after 6 weeks. 12 weeks. 6 months & 12 months period of observation. Clinically all the treated teeth were successful except one fare up in group B. Radiologically the mean decrease in radiolucency with apexit (group A) after 12 months was 0.56: with lodoform (group B) 1.12 & with resorcinol (group C) 1.08 & the percentage decrease was 93.26, 85.92 & 86.76 respectively. There was no statistical difference in all the three groups: however, apexit was marginally better. The post operative complications were minimum with all the sealers. Single visit root canal therapy can be recommended as treatment modality in today's fast world, as it definitely saves time.