|Year : 2016 | Volume
| Issue : 2 | Page : 109-110
3D Printing: Future of dentistry?
Senior Associate Editor, Journal of Indian Academy of Oral Medicine and Radiology
|Date of Web Publication||2-Dec-2016|
Senior Associate Editor, JIAOMR Editorial Office, C/O Department of Oral Medicine and Radiology, Mamata Dental College, Giriprasad Nagar, Khammam - 507 002, Telangana
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Konidena A. 3D Printing: Future of dentistry?. J Indian Acad Oral Med Radiol 2016;28:109-10
| Introduction|| |
Digital technology has crept into the field of dentistry approximately a few decades ago but continues to revolutionize this speciality escalating it to reach new horizons through the advent of three-dimensional (3D) printing. Digitalization promotes task completion in a faster, easier, accurate manner and permits customization. 3D printing is a process of producing 3D solid objects from a digital file in STL format (Surface tesselation language file or Standard triangulation language file) by a 3D printer by joining, bonding, sintering or polymerizing small volume elements.  3D printing may thus revolutionize healthcare by playing a significant role in achieving personalized medicine trends.
| Applications of 3D Printing in Biomedical Fields|| |
Applications of 3D printing in medicine and allied fields are quite diverse which majorly include bioprinting tissues and organs, creation of customized prostheses, implantable devices, anatomic models for high risk surgeries and pharmaceutical drug delivery. ,, Organ printing might reduce the shortage of donor organs, but is still in infancy. Organ printing takes the advantage of 3D printing technology to produce cells and biomaterials individually or layer by layer, fabricating 3D tissue-like structure. 3D bioprinting offers several additional important advantages beyond traditional regenerative method such as precise cell placement, high speed, resolution, cell concentration and diameter of printed cells. In situ printing may be an upcoming future trend, in which implants or living organs may get printed in the human body during operations.
Furthermore, 3D printing permits the designing of accurate custom-made prostheses and implants. 3D printing also has the potential to produce personalized medicines in new formulations such as pills that include multiple active ingredients, as complex multilayer or multireservoir printed tablets, microcapsules, nanosuspensions, multilayered drug delivery devices. 
Dental applications include the production of working models, dental restorations (crowns, bridges, veneers), customized dental implants, dentures (removable or fixed), orthodontic appliances, surgical templates and reconstruction. The time consuming traditional methods of molding, casting can be replaced by faster, accurate methods of scanning and 3D printing. The advantages include faster, smoother treatment procedures with greater precision (due to pretreatment planning) and the superiority of the appliances in terms of fit and function. 
| Technique of 3D Printing|| |
3D printing involves the acquisition of data, data processing, and manufacturing. Data acquisition is usually through a detailed computed tomography scan or magnetic resonance imaging (MRI) scan. A 3D object can be made in almost any shape, as defined in a computer-aided design (CAD) file. The 3D printer follows the instructions in the CAD file to initially build the foundation for the object by moving the printhead along the x-y plane and then builds the object, vertically by moving along the z axis, layer by layer allowing the fabrication of customized anatomical and medical structures. , Apart from the shape, information regarding color, texture, and thickness of the object is obtained through the STL file format. The materials used for 3D printing to fabricate structures intended for human use should be medically safe and biocompatible. Various materials used for 3D printing include ABS plastic, stereolithography materials (epoxy resins), PLA, polyamide (nylon), glass-filled polyamide, silver, steel, titanium, photopolymers, wax, polycarbonate. 
| Types of 3D Printing|| |
Earlier manufacturing of 3D models was done by subtractive manufacturing, where a sharp tool was used to mechanically cut a material to achieve a desired geometric design with the help of a computer program. This method, however, results in wastage, but had been demonstrated to reduce the manufacturing time considerably especially for complex models. The more recent technology in 3D printing is the additive technology wherein materials are joined to make 3D objects usually layer by layer from 3D model data. The process involves creating a series of cross-sectional slices from a 3D file and printing one slice on the other to form a 3D model. The various forms of additive printing include stereolithography, fused deposition modeling, selective electron beam melting, laser powder forming, and inkjet printing. 
Stereolithography involves the use of thin layers of an ultraviolet curable material to make solid objects by placing it layer by layer which are added by polymerization. In fused deposition modeling, the model or part is produced by extruding small beads of a thermoplastic material to form layers as the material hardens immediately after extrusion from the nozzle. Selective electron beam melting manufactures parts by melting metal powder layer by layer with an electron beam in a high vacuum. Laser-based additive manufacturing, such as selective laser melting (SLM) and selective laser sintering (SLS), is accomplished by directing a high power laser using mirrors at a substrate consisting of a fine layer of powder, causing it to melt and later fuse. It is laid as one layer thickness at a time, as per the scanned cross-section, till the desired object is printed. Inkjet printing propels individual small droplets of "ink" toward a substrate and constructs the object. The ink may range from an aqueous solution of coloring agents and binders to a ceramic suspension to produce zirconia dental restorations. 
| Shortcomings|| |
Like two sides of a coin, however, current 3D printing techniques face some limitations such as higher costs for production, reduced choice for materials, colors and surface finishes, lower precision relative to other technologies, limited strength and resistance to heat and moisture. They are further complicated by unrealistic expectations, regulatory and safety concerns. 
| Conclusion|| |
3D printing facilitates revolutionary biomedical applications, including dental restorations, implants and prostheses in a faster, accurate, customized manner, and hence, paves the way towards personalized medicine. The advent of newer materials and techniques may overcome the current shortcomings and transform the world of dental care.
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