Tamil Selvan

The restorative needs for the prosthodontic patient frequently require an increase in occlusal vertical dimension (OVD). This may be due to loss of tooth structure and concomitant loss of OVD, supereruption of opposing teeth into edentulous spaces, or for esthetic reasons. It is often difficult to assess whether OVD has truly been lost. Therefore, it may be prudent to focus on whether alteration in OVD is restoratively acceptable. Another consideration for the alteration in OVD is changes in soft tissue profile. In addition to the correct proportions of the teeth, the relationship of the teeth to the lips and gingiva is also an important factor for an esthetic smile. During a normal smile, the upper lip should rest at the level of the mid-facial gingival margins of the maxillary anterior teeth.4 Furthermore, the gingival outline of the maxillary anterior teeth should follow the upper lip line. The incisal edges of the maxillary anterior teeth should follow the curvature of the lower lip. As the vertical dimension of occlusion increases, the distance between the maxilla and the mandible is increased.

Selection for lithium disilicate glass-ceramic (LDGC) restorations have increased significantly in the field of prosthetic dentistry. The material possesses remarkable beauty and strength and is composed of an acicular crystalline material (70%) embedded in a glassy matrix. The translucency, esthetics and successful clinical performance have made LDGC one of the most popular all-ceramic materials. With the increased demand for metal-free restorations, LDGC meets the requirement for a material possessing strong mechanical properties combined with the optical properties of natural teeth. Mechanical strength is one of the main factors that determines the clinical success of all-ceramic restorations. In vitro studies report flexural strength of 360-440 MPa and fracture toughness of 2.25-2.75 MPa. These numbers are low when compared to zirconia or even alumina; however, the performance of glass-ceramic should increase after etching, silanization and bonding to prepared dentin using an adhesive resin cement.

In the modern era, a teacher has innumerable responsibilities due to changing needs of our society. Every English teacher knows about English grammar rules and function of the different ways. If we only know how to speak, we should learn to write without grammatical mistake. So, the author has selected the topic for prospective teachers. He had collected from 250 prospective teachers from five Bachelor of Education Colleges in Tirunelveli. He had been getting results, the hypothesis accepted from variables of Gender, Age, Locality of the College, Type of Family and the hypothesis rejected from Major Subject, Type of College, Parental Education, and Parental Occupation. The author gave some recommendations to the prospective teachers in Bachelor of Education Colleges in Tirunelveli. Tamil Selvan hopes, good result will be got by the prospective teachers in their working place. Let's Breathe the Mother Tongue and Love the Second Language.