Esthetic is a natural necessity among all human beings, and the reconstruction of the natural features of prosthesis is considered an important aspect in dentistry. Reconstruction of the natural features in removable prosthesis by characterization of denture BASE is one of the most important factors. In this regard esthetic, in removable prostheses, is achieved through different techniques such as: tooth selection and arrangement, designing the denture BASE and acrylic BASE color. The final goal for all these effects is to achieve a natural appearance for denture. However, other factors such as treatment limitations, different personal needs and general health principles, should be taken into consideration. This article not only reviews the natural appearance of oral mucosa that is replaced by the denture BASE, but also discusses about the materials used in tinting acrylic denture BASE and their application techniques.

Introduction: The BASE metal ceramic restorations are one of the most popular restorations in the world. No research has been done about the porcelain metal junction on the occlusal surface yet.The main purpose of this study was to find the best location for porcelain metal junction with regard to occlusal contact in BASE metal- ceramic crown.Materials &Methods: 75 Porcelain Fused to Metal (P.F.M) crowns were made for metal dies. Crowns were cemented on the respective die with zinc phosphate cement and were divided into three groups of25 samples.Occlusal contact in each group was as follows:First group (A): On the porcelain metal junction.Second group (B): 2mm away from the porcelain metal junction on the porcelain.Third group (C): 2mm away from the porcelain metal junction on the metal.All of the samples were prepared for compressive force with Instron machine.Data were analyzed with one way ANOV A and Duncan tests. Results: 1) The average force was different in each of the 3 groups significantly. 2) Group B had the lowest amount of force (290kgF) and group C had the greatest amount (713kgF).3) Group A developed a force between B& C (529kgF).Conclusions: 1- The best location for occlusal contact in the porcelain metal junction restorations is on the metal.2- When the occlusal contact is on the porcelain metal junction, It needs more force for porcelain fracture than when it is on the porcelain.

Introduction: Correction of deep overbite and achieving a long-term stability are still major concerns for many orthodontists. There are three main ways for solving this problem: Bypass arch technique introduced by Ricketts, Segmented arch technique introduced by Burstone and using TADs. The aim of this study was to evaluate and compare the effects of Ricketts and Burstone techniques during correction of deep overbites.Materials and Methods: In this clinical trial, 18 female patients with Cl I and II occlusion and more than 4 mm of overbite were selected. The subjects were divided into two groups (n=9). The deep overbite in group A was treated with Ricketts technique and Burstone technique was used for correction of overbite in group B. Fifteen jaws were included in each group. Lateral cephalograms before and after intrusion were used to evaluate the results. Data were statistically analyzed with Student’s t-test and SPSS 18 (a=0.05).Results: There was a statistically significant difference in the means of true intrusion and extrusion between groups A and B (p value=0.014 and p value=0.47, respectively). However, overbite reduction was not significantly different between the two groups (p value=0.704). In addition, the differences in mean false intrusion (p value=0.02), changes in the axial inclination of posterior teeth (p value=0.047) and the angle between axial inclination of upper and lower anterior teeth (p value=0.002) were statistically significant between the two groups.Conclusion: Under the limitation of the present study, the results confirmed the superiority of Burstone technique in intruding incisors with less undesirable lateral movements.

Color matching and accurate shade selection are the challenging problems common to restorative dentistry. In ceramometal restorations, the type of substructure alloy affects the final color of bonded porcelain. Nickel- chromium alloy is the most commonly used one that its Iranian product, namely Minalux, is similar to Verabond2.Purpose: The aim of this study was to assess and compare various color dimensions resulting from Minalux and Verabond2 alloys. Materials and Methods: Nine disks, approximately 16 mm in diameter and 0.5 mm thickness, were cast from each alloy. Then, porcelain Vita VMK68 A2 was baked onto the entire test disks, following the manufacturer"s instruction. Color samples, at the same time and under the same conditions, was measured by Data color spectrophotometer in CIE Lab System and Munsel system under four light sources (A, C, D65 and TL81). Then MATLAB TOOL BOX Statistic 5.2 was used to determine mean and bilateral variance analysis.Results: It was indicated that the F value on hue, value and chroma was less than of the table value stated with 99% coefficient confidence, confirming Ho theory. In other words, there were not any significant differences between ceramometal disks made of Minalux and Verabond2 in the three dimensions of color.Conclusion: Having desirable physical, mechanical and biological properties, Verabond2 can be replaced by Minalux alloy.