Normal mastication with its varying magnitude and direction generates considerable reactionary stresses in teeth and their supporting tissues. The structure of the human tooth and its supporting tissues is a complex assemblage of materials of varied mechanical properties. The finite element method (FEM), a modern technique of numerical stress analysis, has the great advantage of being applicable to solids of irregular geometry and heterogeneous material properties and therefore ideally suited to the examination of structural behavior of teeth. The mandibular first permanent molar is one of the earliest permanent teeth to erupt in the oral cavity and hence most prone to caries. The purpose of the present study was to construct a two-dimensional FE model of the mandibular first permanent molar and its supporting structures, using a FE software called NISA II-Display III, EMRC, USA to study the following:• To compare stress distributions patterns when a modeled Class I Cavity was restored with dental amalgam and composite resin.• To compare the stress distributions pattern when the load was applied to different to locations, i.e.: At the mesial cusp tip, and at the center of the occlusal surface.Both amalgam and composite resin showed similar stress distribution pattern, however, the magnitudes of stresses generated in the tooth restored with composite resin were higher. Thus, amalgam is a better restorative material in distributing stresses.

The endodontic triad comprises of cleaning and shaping, disinfection and obturation. Success of root canal therapy is majorly achieved by proper cleaning and shaping. However, elimination of bacterial contaminants as well as necrotic debris of the canals requires the adjunctive use of irrigants. To achieve a satisfactory biological and mechanical preparation proper selection of endodontic instruments and irrigants is necessary. In this study we are comparing and evaluating cleaning efficacy of endofiles (K-files and handprotapers ) and root canal irrigants (sodium hypochlorite and chlorhexidine) by microbial quantification. Root canal samples were collected in autoclavable bottles containing transport media (nutrient broth) and samples were cultured in tryptose soya agar at incubation temperature of 37°C for 24-48 hours and colonies were counted with digital colony counter. The significance of this study is to help the clinician select proper instrument and irrigant which minimize the failure rate of root canal treatment for the benefit of patients.

No abstract

No abstract

This case report throws light on treatment of immature apices through apexogenesis and an esthetic postobturation restoration of traumatized young permanent central incisor using a relatively newer methodology of anatomic posts, i.e. shaping the post to the root anatomy. The authors would also like to underline the significance of rubber dam isolation for more predictable outcomes. The new method of anatomic post is simple, viable, practical, and less time consuming than thought.