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A key factor for the success or failure of a dental implant is the manner in which stresses are transferred to the surrounding bone. This depends on the type of loading, bone–implant interface, the shape and characteristics of the implant surface and the quality and quantity of the surrounding bone. This study was done to evaluate the pattern of stress distribution with two different implant designs in four different densities of bone using 3D finite element analysis. Graphic pre-processing software Ansys version 10 was used for creating the geometric configuration of a section of the mandible with a missing first molar. Eight 3D models of this section restored with implant-supported all ceramic crowns were created. Four of these models were created to simulate a single threaded implant placed in four different densities of bone (D1, D2, D3 and D4). The other four models were created to simulate a single cylindrical implant placed in four different densities of bone (D1, D2, D3, and D4). The Poisson’s ratio (μ) and Young’s modulus (E) of elasticity of the material were incorporated into the model. An average vertical load of 400 N was applied on the occlusal surface of the first molar between the buccal cusp, central fossa and the marginal ridge. Maximum Von Mises stresses in all the eight models were observed at the crestal region or neck of the implant. The stresses observed were more for the threaded implants in all the four densities of bone when compared to that of the cylindrical implants. The study concluded that the cylindrical implant design was more favorable in softer bone than the threaded implant design.

Aims and objectives To evaluate and compare the effect of fiber reinforcement on the dimensional changes of heat-cured poly (methyl methacrylate) resin after processing and immersion in water. Materials and methods Three different heat-cure resins were selected for the present study: (1) Nonreinforced heat-cure methyl methacrylate resin, (2) High Impact heat-cured methyl methacrylate resin and (3) Fiberglass reinforced methyl methacrylate resin. Ninety samples were prepared using three different resins and denture bases obtained for the same. The amount of space between the tissue surface and the cast in the anterior, middle and posterior regions is measured after processing and immersion in water for 17 days using a traveling microscope having a least count of 0.001 cm. Results Mean and standard deviation were calculated for the dimensional changes and were subjected to statistical analysis (Student t-test, unpaired). Among the three groups of resins, fiber reinforced heat-cured methyl methacrylate resin was found to be statistically highly significant in terms of dimensional changes when compared with the nonreinforced and high impact heat-cured resins. Conclusion Dimensional changes were evident in all the planes in the three groups studied and were in the following decreasing order—fiberglass reinforced heat-cured poly (methyl methacrylate) resin, high impact heat-cured poly (methyl methacrylate) resin and nonreinforced heat-cured poly (methyl methacrylate) resin. Clinical significance The fibers are added in order to increase the strength of acrylic resin. Considering only the strength may in turn affect the dimensional accuracy of the acrylic resin resulting in loss of retention and stability, affecting the fit of the denture. How to cite this article Ranganath LM, Shet RGK, AG Rajesh, Abraham S. The Effect of Fiber Reinforcement on the Dimensional Changes of Poly Methyl Methacrylate Resin after Processing and after Immersion in Water: An in vitro Study. J Contemp Dent Pract 2011;12(4):305-317.

Aim To evaluate the influence of salivary contamination during dentin bonding procedures on shear bond strength and to investigate the effect of contaminant-removing treatments on the recovery of bond strength for two dentin-bonding agents. Materials and methods Seventy-seven human maxillary and mandibular molars were randomly divided into two groups for total-etch adhesive (Single bond-3M ESPE, USA) and self-etch primer (UniFil Bond-GC, Tokyo, Japan) and subjected to contamination with saliva. The data for each group were subjected to one-way analysis of variance (ANOVA) followed by the Student Newman-Keuls test to make comparisons among the groups (p < 0.05). Results Salivary contamination had less adverse effect on the shear bond strength of single bond total-etch adhesive when it was blot dried or washed. UniFil bond was tolerant of salivary contamination, except when contamination occurred after application of the primer. Conclusion In single bond adhesive, when the etched surface is contaminated by saliva, blotting the surface and applying the primer can recover the bond strength. Complete drying of the salivary contaminated surface should be avoided. In the UniFil bond groups, the repriming treatment (UF-V and UF-VI) resulted in the recovery of shear bond strength in the specimens contaminated after priming. Clinical significance The results of this study showed that total- etch adhesive (single bond) was not affected by salivary contamination on the etched surface when the bonding surface was kept moist. Self-etch adhesive (UniFil bond) also tolerated salivary contamination except when the contamination occurred after application of the primer. How to cite this article Justin RM, Paranthaman H, Rajesh AG, Varghese RP, Ranganath LM. Effect of Salivary Contamination on the Bond Strength of Total-etch and Selfetch Adhesive Systems: An in vitro Study. J Contemp Dent Pract 2012;13(5):655-660.

Objective The purpose of this study was to evaluate, using scanning electron microscopy (SEM), the morphological and structural changes of the enamel induced by three bleaching agents namely old McInnes solution, modified McInnes solution and 10% carbamide peroxide gel at different time intervals. Materials and methods Fifteen freshly extracted noncarious human central incisors with intact enamel surface were selected. The teeth were sectioned at the cementoenamel junction separating the crown portion from the root using a diamond separating disk. Following this, the samples were subjected to three different bleaching agents: Group 1: Old McInnes solution, group 2: modified McInnes solution and group 3: 10% carbamide peroxide for a period of 15, 30 and 60 minutes, 24 and 30 hours time interval. The sample stubs were subjected to scanning electron microscope and were photographed at 2000 and 10,000 magnifications. Conclusion The present study revealed no indication of either etching or significant change in surface morphology of enamel when evaluated under scanning electron microscope after 6 weeks treatment with various bleaching agents. Clinical significance Morphological alterations in bleached enamel are both concentration and time dependent. How to cite this article Rajesh AG, Ranganath LM, Kumar KSP, Rao BS. Surface Morphological Changes in Human Enamel Following Bleaching: An in vitro Scanning Electron Microscopic Study. J Contemp Dent Pract 2012;13(3):405-415.

Saliva plays a vital role in oral health as patients strive to maintain a healthy dentition throughout their lives. It is nature's primary defense mechanism for the oral environment, and is particularly important for protecting exposed tooth surfaces. While internal protection for dentin comes from odontoblasts and the dental pulp, the body's external protection for enamel comes from saliva. The noninvasive nature of salivary testing has made it an effective alternative to blood and urine testing and home testing kits have made it possible for people to monitor their own health using this diagnostic medium. This paper presents what saliva can reveal about general and oral health as well as highlights the current use and potential clinical and research applications, of diagnostics based on oral fluids. Clinical significance Early detection always minimizes the need for more invasive treatment. It prevents oral health disease at an early stage and provides a good oral health in rejuvenated state. If you stick and follow regular professional care, prevention maintenance appointments, prevention counseling, good home care and oral hygiene, diet habits you will be free from oral health illness and you can experience the harmonious and rejuvenated state of good oral health. How to cite this article Ranganath LM, Shet RGK, Rajesh AG. Saliva: A Powerful Diagnostic Tool for Minimal Intervention Dentistry. J Contemp Dent Pract 2012;13(2):240-245.