Aim: To evaluate the effect of prosthetic framework material and cantilever length on peri-implant strain in mandibular all-on-four implant-supported prostheses with different types of arch antagonist forces. Materials and Methods: Models simulating a completely edentulous mandibular arch fabricated in heat-cured acrylic resin were used. On the acrylic models, four implants were placed at regions 34, 32, 42, and 44 simulating all-on-four implant placements. Implant-supported screw-retained fixed prosthesis frameworks were fabricated using three different materials (cobalt-chromium, zirconia, and polyetheretherketone) and with three different cantilever lengths (zero mm, 15 mm, and 25 mm). Strain gauges were attached on the model at the buccal and lingual positions of each implant. Forces simulating opposing natural dentition, conventional complete denture, and the parafunctional habit were applied to the models. The peri-implant strain in each strain gauge was recorded. Results: Least peri-implant strains (67 microstrains) were observed when forces simulating conventional complete dentures were applied on the models and the highest peri-implant strains (9091 microstrains) were observed when forces simulating parafunctional habit were applied. One-way ANOVA test followed by Tukey's post hoc analysis was performed to compare the mean deformation scores between different materials at 50 N load. The level of significance [P-value] was set at P < 0.05. Tests showed significant differences between zero mm and the other types in all the different materials, and also between 1.5 x AP and 2.5 x AP for Zirconia and Peek material at P = 0.02 & P = .008, respectively. The results showed that the type of framework material, cantilever length, and occlusal forces from the opposing arch influence the peri-implant strain in the bone in all-on-four implant-supported prostheses. Conclusion: Rehabilitation of a single, completely edentulous arch with implant-supported prostheses should consider the situation of the opposing arch. The choice of framework material, as well as the cantilever length, should be altered based on the forces from the opposing arch.

Aim:The aim of this study is to evaluate the strain developed in simulated mandibular model before and after the joining of an implant-supported screw-retained prosthesis by different joining techniques, namely, arc welding, laser welding, and soldering.Materials and Methods:A specimen simulating a mandibular edentulous ridge was fabricated in heat-cured acrylic resin. 4-mm holes were drilled in the following tooth positions; 36, 33, 43, 46. Implant analogs were placed in the holes. University of California, Los Angeles, abutment was attached to the implant fixture. Eight strain gauges were attached to the acrylic resin model. Six similar models were made. Implant-supported screw-retained fixed prosthesis was fabricated in nickel-chromium alloy. A load of 400 N was applied on the prosthesis using universal testing machine. Resultant strain was measured in each strain gauge. All the prostheses were sectioned at the area between 36 and 33, 33 and 43, and 43 and 46 using 35 micrometer carborundum disc, and strain was measured in each strain gauge after applying a load of 400 N on the prosthesis. Specimens were joined by arc welding, soldering, and laser welding. After joining, a load of 400 N was applied on each prosthesis and the resultant strain was measured in each strain gauge.Results:Highest mean strain values were recorded before sectioning of the prostheses (889.9 microstrains). Lowest mean strain values were recorded after sectioning the prosthesis and before reuniting it (225.0 microstrains).Conclusions:Sectioning and reuniting the long-span implant prosthesis was found to be a significant factor in influencing the peri-implant strain.

Aim: To highlight the concept of prefabricated veneers and occlusal vertical dimension (OVD) and series of case report using edelweiss prefabricated veneer system.Background: Edelweiss prefabricated veneer system presents a concept of biofunctional esthetics using laser sintered composite resins. The system`s biofunctionality and versatile area of application combined with its time and cost saving procedure make the edelweiss veneer and occlusion system a sound investment for the future.Case description: A series of case reports treated using prefabricated laser sintered composite veneer system has been presented. Conclusion:Prefabricated veneer is a milestone in operative dentistry, as it contributes tremendously to direct composite application, helping a larger number of our patients to receive esthetic restorations that are more conservative and affordable. Clinical significance:The prefabricated composite veneering technique provides a minimally invasive, chair-side technique for esthetic and full mouth rehabilitation.

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Aim: To evaluate and compare the stress distribution in periimplant area and posterior region of completely edentulous mandible rehabilitated using implant-retained overdenture (IOD) with two types of ball attachment configuration, i.e., rigid and resilient.Materials and methods: Two mathematical models were prepared simulating completely edentulous mandibular ridge. Model 1 represented implant with rigid stud attachment. Model 2 represented implant with resilient stud attachment. Both the models were subjected to the compressive force of 35 N. The stresses in the peri-implant area and posterior region of the mandible were evaluated and compared for both the models. Results:The IOD with rigid stud configuration showed 12.1% higher peri-implant stresses than resilient configuration, whereas the resultant stress values in posterior edentulous region were 1.5% lower with resilient configuration. Conclusion:Highest stress value was seen in the crestal part of bone around the implant with both rigid and resilient attachment configuration. Implant-retained overdentures with resilient stud attachment showed better dissipation of forces when compared with rigid attachment.Clinical significance: Correct choice of attachment configuration can influence the peri-implant stresses in IOD, which in turn reduces the complications that can be a result of excessive stresses around the implant.