Online ISSN: 2515-8260

Keywords : restorations

Comparison of fracture resistance for chairside cad/cam lithium disilicate crowns and overlays with different designs- An original research

Dr. Uppalapati Vishwaja; Dr Tharini Satheesh; Dr. Manjiri Salkar; Dr. Sachin Yadav; Dr. Dheeraj Kumar Sharma; Dr Rahul Puthenkandathil; Dr. Sirisha Kommuri .

European Journal of Molecular & Clinical Medicine, 2022, Volume 9, Issue 7, Pages 8764-8768

Aim: The purpose of the research was to evaluate the fracture resistance of conventional full coverage crowns and two different designs of overlay restorations with margins located 2 and 4 mm above the gingival level.
Methodology: CAD/CAM lithium disilicate (IPS e.max CAD for CEREC/HT A1 C14, Ivoclar Vivadent) restorations (15 specimens/group) with 1.5 mm occlusal thickness and 1.0 mm chamfer were designed and fabricated with a chairside CAD/CAM system (CEREC, Dentsply Sirona). The restorations were prepared in three different designs: (1) full coverage crowns, (2) overlays with the margin located 2 mm above the gingiva, and (3) overlays with the margin located 4 mm above the gingiva. Restorations were cemented using conventional resin luting cement (Multilink, Ivoclar Vivadent) then finally loaded with a steel indenter until failure. Scanning electron microscopy observations of fractured surfaces were also conducted. Group results were analyzed with one-way analysis of variance, and the medians were evaluated independently with Kruskal-Wallis.
Results: The fracture force of CAD/CAM lithium disilicate restorations was significantly different (p < 0.001) depending on the design of the restoration. Full coverage crowns showed significantly higher force to fracture (1018.8 N) than both 
types of overlays (p = 0.002 for overlay 2.0 mm and p < 0.001 for overlay 4.0 mm above gingiva).
Conclusion: Full coverage chairside CAD/CAM lithium disilicate premolar crown showed higher fracture resistance than overlay restorations


Neha N; Dr. Jayalakshmi Somasundaram; Dr. Subhabrata Maiti; Dr.Jessy P

European Journal of Molecular & Clinical Medicine, 2020, Volume 7, Issue 1, Pages 1482-1497

3D printing otherwise known as additive manufacturing, rapid prototyping or layered manufacturing is a relatively new, quickly growing and rapidly expanding method of manufacturing that has got numerous applications in healthcare and also in many other fields. Recently, it has become a subject of great interest in planning surgeries. Additive manufacturing method involves the production of a 3D model by laying down or adding successive layers of material. 3D printers are equipment that produces 3D models using CAD technology or 3D scanners. It has received more importance with the advancement in 3D imaging and modelling technologies such as CBCT, intraoral scanning and CAD/CAM in dentistry. Different techniques are employed in 3D printing namely stereolithography, photopolymer jetting, power binder printers, direct light processing, selective laser sintering, fused deposition modelling, electron beam melting, etc. Dental laboratories are able to produce 3D printed restorations, crowns, bridges, orthodontic appliances, surgical guides and implants quickly with higher precision and accuracy. This is done by methods that combine oral scanning, CAD/CAM designing and 3D printing. The rate of success of 3D printing has improved the quality and accuracy of dental treatment. With the application of 3D printing, it has become possible to replicate the desired complex geometry which was not feasible with conventional techniques. Thus 3D printing has led to a transformation in digital dentistry with its extensive learning and penetrating opportunities and a wide range of applications. The aim of this article was to review the techniques and current applications of 3D printing in dentistry.