|
 
 |
| REVIEW ARTICLE |
|
| Year : 2022 | Volume
: 13
| Issue : 1 | Page : 25-31 |
|
Three-dimensional printing: Fine-tuning of the face of pediatric dentistry
Rishi Tyagi, Namita Kalra, Amit Khatri, M Khadeeja Kulood, Neetu Garg
Department of Paedodontics and Preventive Dentistry, University College of Medical Sciences, Guru Teg Bahadur Hospital, Delhi, India
| Date of Submission | 20-Jan-2022 |
| Date of Decision | 16-Feb-2022 |
| Date of Acceptance | 18-Feb-2022 |
| Date of Web Publication | 14-Mar-2022 |
Correspondence Address:
Dr. M Khadeeja Kulood
Department of Paedodontics and Preventive Dentistry, University College of Medical Sciences, Guru Teg Bahadur Hospital, Dilshad Garden, Delhi
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/srmjrds.srmjrds_6_22
The incessant exploration of technology in the segment of health care and medicine has paved a way to herald the dawn of three-dimensional (3D) and four-dimensional imaging technologies in dentistry. 3D printing also referred to as solid free-form fabrication is a form of rapid prototyping that utilizes additive manufacturing technology in contrast to the subtractive technique of commonly used imaging technology like CAD/CAM. 3D printing has materialized the fabrication of custom-made products that eliminates the exhaustive artisanal labor techniques with reduced work time. It also escalated the accuracy and precision in the production of intricate human details. The purpose of this review is to procure the data summarizing the applications of novel 3D printing technique in the field of pediatric dentistry harnessing enhancement in technology. Furthermore, it compiles data from various clinical trials providing evidence-based approach for promoting the implementation of the techniques into practice.
Keywords: Fused deposition modeling, pediatric dentistry, stereolithography, three-dimensional printing
How to cite this article:
Tyagi R, Kalra N, Khatri A, Kulood M K, Garg N. Three-dimensional printing: Fine-tuning of the face of pediatric dentistry. SRM J Res Dent Sci 2022;13:25-31 |
How to cite this URL:
Tyagi R, Kalra N, Khatri A, Kulood M K, Garg N. Three-dimensional printing: Fine-tuning of the face of pediatric dentistry. SRM J Res Dent Sci [serial online] 2022 [cited 2022 Dec 5];13:25-31. Available from: https://www.srmjrds.in/text.asp?2022/13/1/25/339635 |
| Introduction | |  |
Health care and medicine have explored a prodigious era of digitalization with the introduction of three-dimensional (3D) and four-dimensional imaging technologies that have revolutionized the face of research, treatment approaches, education, and training. 3D printing also called solid free-form fabrication or additive manufacturing is a form of rapid prototyping that has gained its importance in recent years.[1] It has been embraced in different areas of health and medicine including regenerative medicine and tissue engineering, dentistry, engineered tissue models, medical equipment, human anatomical models, organ printing, and the pharmaceutical industry. The heave of research in these fields is illustrated due to its ability to fabricate complex designed details with utmost accuracy and resolution.[1],[2] The 3D technique utilizes patient digital images such as magnetic resonance imaging, computed tomography (CT), and computed axial topography for the construction of personalized designs.[3]
The field of pediatrics identifies the application of 3D printing in various expanses such as surgical planning and decision-making, prosthetics like hearing prosthesis, hand prosthesis, intensive care of preterm infants, tissue structure construction, and pharmaceutical printing. It helps in the simulation of spatial orientation of anatomy for surgical approaches in diseases like congenital heart disease, thereby enhancing management planning. Its utility in the production of pediatric models and patient-specific drugs has gained popularity.[3],[4] The aim of this article is to collate and review the scope and advancement of 3D printing in the field of medicine with emphasis on pediatric dentistry, the steps, techniques, material used, and detailed review on the application of 3D printing [Figure 1]. Furthermore, the review summarizes clinical trials that may provide a way for evidence-based study in the implementation of emerging applications in the field. | Figure 1: Application of three-dimensional printing in pediatric dentistry
Click here to view |
| Three-Dimensional Printing: An Overview in Dentistry | | |
Digital dentistry has been enfolded by dental personnel which can be drawn back to the early 1990s. The CAD/CAM that utilizes subtractive manufacturing technology lacks precision and accuracy which could not completely replace the manual operation whilst its advantage of 3D scanning and designing from biomaterials.[5] The advent of intraoral scanners and the availability of 3D printers with compatible biomaterials enhanced the use of 3D printing technology. Its application in dentistry hands on to restoration (permanent and temporary crown and bridges), physical model preparation, surgical guides, dentures and prosthesis, dental implant guides, implant biomaterial (titanium) production, endodontic guides, manufacture of patient specific tissue regeneration scaffolds, and for orthodontic applications.[2],[3],[5]
Advantages of 3D printing include the production of complex customized products with intricate details, ease of availability, high precision and personalized service with increased quality, economic, no wastage of biomaterials, simplification of the manual workflow with greater accuracy and speed, and efficient delivery of treatment with minimal trauma to the patients. Despite these advantages, there is a lack of soft-tissue replication of these products to the human biological tissue and also requires further evaluation of the physical and mechanical properties produced by the traditional method.[6],[7]
Steps in three-dimensional printing
The steps involved in 3D printing are depicted in [Figure 2].[1],[3],[7]
Techniques of three-dimensional printing in dentistry
3D printing approach broadly employed in dentistry consists of stereolithography, fused deposition modeling, selective laser melting, polyjet, and bioprinting.[1],[8]
Stereolithography (SLA)
SLA, developed by Charles Hull in 1983, is the first commercially available 3D printing process.[2] It uses the photopolymerization principle with the help of an ultraviolet laser for the fabrication of parts [Figure 3]a and [Figure 3]b. SLA is the most common technique utilized for dental practice [Figure 3]c.[5] It is used for designing titanium implants, surgical guides for implants, resin models for temporary crown and bridge, and patient-specific scaffolds for regeneration.[2] | Figure 3: Techniques of three-dimensional printing in dentistry. (a) Stereolithography (Picture courtesy: Tech Vue labs). (b) Postprocessing unit of stereolithography (Picture courtesy: Tech Vue labs). (c) Schematic representation of the mechanism of action of stereolithography. (d) Schematic representation of selective laser sintering. (e) Schematic representation of the mechanism of FDM. (f) Fused deposition modeling (Picture courtesy: Tech Vue labs)
Click here to view |
Selective laser melting (SLM)/sintering
SLM constitutes 99% of the 3D printing of metal products. Here, a high power density laser is used to soften and fuse the metal powder, after which fixed slices are received from these 3D shapes, which accumulates layer by layer to form the desired parts [Figure 3]d.[9],[10] It has been used for the fabrication of dental implants constructed using biocompatible metal or ceramic material.[1],[2]
Polyjet
Polyjet utilizes array-typed showerheads that spray liquid photosensitive polymer on the platform in an orderly manner. During the event, the printer head moves in the horizontal and vertical direction and the roller flattens the resin surface layer. The nozzle continues to spray the photosensitive resin for printing of the next layer and continuation of the process.[1],[2] It is used in designing craniofacial implant.[7]
Fused deposition modeling
The filamentous base material melts and the nozzle moves along the 2D structure and the material superposes and gets bonded to the previously formed entity to form a 3D structure [Figure 3]e and [Figure 3]f.[2] Plastic materials with a low melting point have been conformed using this technique.[1],[7]
| Materials Used in Dental Three-Dimensional Printing | | |
Materials commonly used in 3D printing in dentistry include:
Polymers (plastics and composites)
Polycaprolactone
PCL is a semi-crystalline aliphatic thermoplastic biodegradable resin that has a low melting point (63 ° C) and softens around 40°C. It has its application in 3D dentistry due to its property of oral tissue repair which helps in the improvement of the regenerative process of bone and hard-tissue complex.[1],[11]
Polylactic acid
PLA is a rigid green polymer obtained from renewable monomers which require an optimum temperature to show the properties of a 3D material. It is a biocompatible, biodegradable, thermally stable material with good physicochemical properties that helps these scaffolds as a good choice for an endoprosthesis that supports the inner walls of the tubular lumen of the body.[1],[12],[13]
Acrylonitrile butadiene styrene
ABS is an oil-based material with high durability. It has a bone stimulatory effect with easier processing. ABS material when fused with hydroxyapatite forms a composite material whose role in dental implant [Figure 4]a could be a promising realization in the field.[1],[2],[14] | Figure 4: (Picture courtesy: Tech Vue labs). (a) Software used for designing dental implant for three-dimensional printing. (b) Crown and bridge fabricated by three-dimensional technique. (c) Software used for designing of anterior tooth crown. (d) Designing of NAM in a cleft patient
Click here to view |
Poly lactic-co-glycolic acid
It is biocompatible material as the parent materials are biological byproducts. However, at a higher temperature, they may form toxic material and structural crosslinking. Its extensive application in 3D printing is due to its well-defined architecture and regular-sized pores which lead to high transparency and porosity.[1],[15]
Bio-inorganic material
Ceramic
Bioinert ceramics include carbon, alumina (Al2O3), zirconia (ZrO2), and single oxide ceramic. They allow the development of capsules that are fibrous in nature without forming any physical bond with the bone.[1],[16],[17] They have the disadvantage of shrinkage during the sintering process. The repair adaptivity is low which may lead to secondary caries and microleakage in teeth with zirconia restoration if not processed accurately. With rapid advancement, nanozirconia has increased demand for its superior properties. Restorative material like porcelain-fused metal dental crown is another category of ceramic material that has its place in 3D dentistry. They possess high compressible and tensile strength with adorable esthetics.[16]
Hydroxyapatite
HA with a formula Ca10(PO4) 6(OH) 2 is the main component of human hard tissue including teeth. HA has the advantage of promoting osteogenesis, compatible biological fixation to human tissue due to its properties of osteoconductivity.[18] Nanosized HA particles synthesized by 3D technique are similar to hydroxyapatite found in the biological system. Smaller HA particles have additional characteristics of better adhesion, cell growth, and cellular adherence with the host cells.[1],[2]
Plaster
Plaster is a chemical cement with a formula of CaSO4.1/2 H2O. It has excellent properties and expansion of gypsum products after setting imparts surface smoothness with appealable texture. Stereolithographic printers are used for digital printing using plaster. It helps in the construction of digital libraries and reaches of plaster cast conversion when required.[1]
Metal
The main advantage of dental metal material is that it has comparable strength, compatible with human tissues (except certain allergic metals), is nontoxic, has resistance to tarnish and corrosion, and adapts to human biological tissues with easy fabrication and processing. However, they are expensive even though having superior performance. Ti-Zr alloy, titanium alloy, Co-Cr alloy, etc., have been used for fabrication of dental prosthesis.[19],[20]
Application of three-dimensional in pediatric dentistry
Various applications of 3D printing in dentistry include:
Advances in restorative treatment
The demand for esthetics has led to development of preveneered stainless steel crown, and the introduction of zirconia has changed the notion of pediatric restorative treatment with its high esthetic value, clinical performance, and durability. CAD/CAM technology has driven the development of customized economic restorations with perfect occlusal contour and excellent marginal integrity.[6],[21] Recently, introduction of 3D printers has impactfully changed the facets of restoration. 3D printing using digital light processing systems has made it possible to print provisional and temporary crowns and bridges [Figure 4]b and [Figure 4]c. MN Al-Halabi et al. have reported a success rate of 84% with 3D printed composite crowns for a molar tooth for a 12-month follow-up.[22] There was a positive correlation with gingival health. The smooth surface texture exhibited by the crowns printed by 3D printers resulted in less accumulation of plaque and thereby gingivitis. They also resulted in less biomaterial wastage up to 40% when compared with milling technology (Azari 2009).[23] Strip crowns are also customized using 3D printing. Scanned data of the model obtained by impression are saved as an STL file; crown is designed to fabricate strip crown.[24]
Three-dimensional printed space maintainers
Space maintainer could be fabricated using biomaterials such as titanium-based powdered metal material or clear photopolymer resin. After taking an impression of the patient, the cast is poured which is then scanned and designed for 3D printing. The chances of fracture or solder failure are mitigated as it is printed as one unit with no need of polishing and thereby saving chair side time.[24]
Three-dimensional printing and nasoalveolar molding therapy
The use of presurgical infant orthopedics aids in the molding of alveolar structure and its alignment, by utilizing the intrinsic growth potential prior to surgical lip repair. Digital models of the patient provide virtual treatment planning, guiding the plausible direction of treatment and prognosis. It is followed by digital designing of the complete sets of appliances according to desired term and fabrication by 3D printing technology [Figure 4]d. It automates the process of planning.[25],[26] Yue Du et al. (2021) had carried out a study with methacrylate material as a biomaterial for fabrication of 3D printed NAM. Tools are yet to be developed which may account for patient growth and the biocompatibility and durability of the 3D printed appliance.[27]
Three-dimensional printing in malocclusion
3D printing has been evolved in different processes of orthodontic treatment – digital cephalometric and analysis, patient-specific brackets, anchoring appliances, lingual retainers, and impression trays that have been fabricated by 3D printing technology. It has extended application in treatment planning for better visualization of prognosis (Gupta et al. 2015).[28]
Myofunctional therapy has now estimated the advantage of 3D printed appliances to that of conventional treatment. Class II malocclusion with mandibular deficiency during active growth is managed using myofunctional therapy.[29] Digital lingual retainers are gaining popularity in the recent scenario. Chairside time consumed for constructing the bite is reduced. An increased fit and superior accuracy has also been observed over the traditional method.[30]
Three-dimensional printing and management of dental and craniomaxillofacial trauma
Pediatric patients with concomitant maxillofacial trauma followed by malocclusion and dental trauma require strategized and deliberate treatment plans that would not restrict or delay the growth potential of the bone and the development of tooth germs or impede psychological status of the child. A study report by Lopez et al. (2018) has utilized a combination of 3D printing, CAD/CAM, and positioning bite plane for surgical guidance in the management of an unstable mandibular fracture.[31]
Autotransplantation of permanent tooth and endodontic therapy
Autotransplantation using 3D printing process adds merit of utilizing the model tooth as a surgical guide in making the recipient socket which reduces the extraoral dry time for a natural tooth and the damage to the periodontal support structure.[32]
3D image analysis provides an enhanced aspect of the root morphology specifically in the case of primary tooth which has a ribbon-shaped root canal morphology. 3D printing could be used in preoperative treatment planning, as endodontic access guides and has additional advantages in regenerative treatment too.[33]
Management of craniomaxillofacial congenital anomalies
With an interdisciplinary approach, 3D printing technology could be used in the assistance of repair in prefabricated skull defects. 3D printing has materialized a bioceramic scaffold which serves to function as an autogenous graft with osteogenic potential and safety profile for pediatric bone tissue engineering; it could provide a local delivery mechanism that possibly enhances the extracellular concentration of adenosine that induces osteogenesis and also finds application in congenital anomalies such as craniosynostosis and microtia.[34]
Other dental applications of 3D printing
Patient and parent education
Patient and parent education about treatment outcomes and possibilities could reduce the anticipated anxiety and concern for dental treatment in children.[5]
Medical models for enhanced education and treatment planning
3D printed patient models would provide a deeper insight into the anatomic visualization of structures that would foster learning and help in providing enhanced treatment to the patient. It could also provide better knowledge about osteoporotic conditions.[5],[7]
Customized tools, instruments, and appliances
3D printing could also be used for the manufacture of customized designs of mundane instruments in everyday practice such as band fabrication instruments and bracket placement tools.[5],[7] It could also be used for fabricating custom-made protective appliances for the patient who needs general anesthesia to prevent aspiration of materials and dental injury during intubation.[35]
Personalized drug printing
The 3D printed pharmaceutical application could provide desired dosage of the drug depending on child anthropometric characteristics. And print powdered drug layers for the rapid dissolution of pills for better compliance of pediatric patients.[32]
Three-dimensional printed food and biobased products
3D printed foods composed of different sources of protein or other macromolecules have been in consideration by the researchers that would meet personalized nutrient requirements. Derossi A et al. (2021) have reviewed numerous applications of customized food for certain medical conditions and targeted groups.[33] Experiments have been carried out in these fields to expand its application in every sector. Studies were also conducted (Portanguen et al. 2019) to investigate the effect of two variables, on the printability to deliver 5%–10% of energy, calcium, iron, and Vitamin D required for a food-based formulation for children under 10 years.[34]
Three-dimensional printing and its expansion in pediatric dentistry
3D printing in pediatric dentistry unfolds a new era that would ease the treatment in children. Randomized clinical trials and literature reviews provide evidence-based study promoting the implementation of novel techniques into practice. Some of the studies are listed in [Table 1]. | Table 1: Clinical trials depicting the emerging application of three-dimensional printing in pediatric dentistry
Click here to view |
| Conclusion | | |
3D printing unquestionably emulated a beneficial impression in dentistry. Appropriate regulatory standards are to be set as guidance in the utilization of these technologies. Future perspectives could focus on the introduction of nanotechnology to integrate biomolecules that simulate living cells, fabrication of materials with hybrid components, and construction of biological materials that would aid in the regeneration, revascularization, and development with the growth of tissues. The innovative concepts of microgel-loaded scaffolds have been introduced to the field where researchers have conducted an in vitro study that results in a significant increase in the ability to direct cell migration toward desirable niches. Further studies and researchers in the 3D printing scenario would enhance and finely tune the fields of pediatric dentistry as dentistry is an arena where dentist skills and a multitude of factors determine the success of treatment[38].
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
| References | | |
| 1. | Lin L, Fang Y, Liao Y, Chen G, Gao C, Zhu P. 3D printing and digital processing techniques in dentistry: A review of literature. Adv Eng Mater 2019;21:1801013.  |
| 2. | Touri M, Kabirian F, Saadati M, Ramakrishna S, Mozafari M. Additive manufacturing of biomaterials − The evolution of rapid prototyping. Adv Eng Mater 2019;21:1800511. |
| 3. | Liaw CY, Guvendiren M. Current and emerging applications of 3D printing in medicine. Biofabrication 2017;9:024102. |
| 4. | Sukanya VS, Panigrahy N, Rath SN. Recent approaches in clinical applications of 3D printing in neonates and pediatrics. Eur J Pediatr 2021;180:323-32. |
| 5. | Oberoi G, Nitsch S, Edelmayer M, Janjić K, Müller AS, Agis H. 3D printing-encompassing the facets of dentistry. Front Bioeng Biotechnol 2018;6:172. |
| 6. | Aimar A, Palermo A, Innocenti B. The role of 3D printing in medical applications: A state of the art. J Healthc Eng 2019;2019:5340616. |
| 7. | Pillai S, Upadhyay A, Khayambashi P, Farooq I, Sabri H, Tarar M, et al. Dental 3D-printing: Transferring art from the laboratories to the clinics. Polymers (Basel) 2021;13:157. |
| 8. | Della Bona A, Cantelli V, Britto VT, Collares KF, Stansbury JW. 3D printing restorative materials using a stereolithographic technique: A systematic review. Dent Mater 2021;37:336-50. |
| 9. | Awad A, Fina F, Goyanes A, Gaisford S, Basit AW. 3D printing: Principles and pharmaceutical applications of selective laser sintering. Int J Pharm 2020;586:119594. |
| 10. | Louvrier A, Euvrard E, Nicod L, Rolin G, Gindraux F, Pazart L, et al. Odontoblastic differentiation of dental pulp stem cells from healthy and carious teeth on an original PCL-based 3D scaffold. Int Endod J 2018;51 Suppl 4:e252-63. |
| 11. | Tagami T, Nagata N, Hayashi N, Ogawa E, Fukushige K, Sakai N, et al. Defined drug release from 3D-printed composite tablets consisting of drug-loaded polyvinylalcohol and a water-soluble or water-insoluble polymer filler. Int J Pharm 2018;543:361-7. |
| 12. | Evans KA, Kennedy ZC, Arey BW, Christ JF, Schaef HT, Nune SK, et al. Chemically active, porous 3D-printed thermoplastic composites. ACS Appl Mater Interfaces 2018;10:15112-21. |
| 13. | Zehnder MS, Connert T, Weiger R, Krastl G, Kühl S. Guided endodontics: Accuracy of a novel method for guided access cavity preparation and root canal location. Int Endod J 2016;49:966-72. |
| 14. | Jammalamadaka U, Tappa K. Recent advances in biomaterials for 3D printing and tissue engineering. J Funct Biomater 2018;9:E22. |
| 15. | Zhao L, Si J, Wei Y, Li S, Jiang Y, Zhou R, et al. Toxicity of porcelain-fused-to-metal substrate to zebrafish (Danio rerio) embryos and larvae. Life Sci 2018;203:66-71. |
| 16. | Karadzic I, Vucic V, Jokanovic V, DebeljakMartacic J, Markovic D, Petrovic S, et al. Effects of novel hydroxyapatite-based 3D biomaterials on proliferation and osteoblastic differentiation of mesenchymal stem cells. J Biomed Mater Res A 2015;103:350-7. |
| 17. | Qin J, Yang D, Maher S, Lima-Marques L, Zhou Y, Chen Y, et al. Micro- and nano-structured 3D printed titanium implants with a hydroxyapatite coating for improved osseointegration. J Mater Chem B 2018;6:3136-44. |
| 18. | Camardella LT, Vilella OV, van Hezel MM, Breuning KH. Accuracy of stereolithographically printed digital models compared to plaster models. J Orofac Orthop 2017;78:394-402. |
| 19. | Peng CC, Chung KH, Ramos V Jr. Assessment of the adaptation of interim crowns using different measurement techniques. J Prosthodont 2020;29:87-93. |
| 20. | Al-Halabi MN, Bshara N, Nassar JA, Comisi JC, Rizk CK. Clinical performance of two types of primary molar indirect crowns fabricated by 3D printer and CAD/CAM for rehabilitation of large carious primary molars. Eur J Dent 2021;15:463-8. |
| 21. | Soni HK. Application of CAD-CAM for fabrication of metal-free band and loop space maintainer. J Clin Diagn Res 2017;11:D14-6. |
| 22. | Khanna S, Rao D, Panwar S, Pawar BA, Ameen S. 3D printed band and loop space maintainer: A digital game changer in preventive orthodontics. J Clin Pediatr Dent 2021;45:147-51. |
| 23. | Kasper FK, Ghivizzani MM, Chiquet BT. Emerging applications of 3D printing in nasoalveolar molding therapy: A narrative review. J 3D Print Med 2019;3:195-208. |
| 24. | Ahsanuddin S, Ahmed M, Slowikowski L, Heitzler J. Recent advances in nasoalveolar molding therapy using 3D technology. Craniomaxillofac Trauma Reconstr. 2021:194338752110446. |
| 25. | |
| 26. | Tartaglia GM, Mapelli A, Maspero C, Santaniello T, Serafin M, Farronato M, et al. Direct 3D printing of clear orthodontic aligners: Current state and future possibilities. Materials (Basel) 2021;14:1799. |
| 27. | Du Y, Yang D, Pang Y, Liu C, Zhang K. Application of CAD and 3D printing in the treatment of pediatric multiple mandible fractures. Med Case Rep Study Protoc 2021;2:e0095. |
| 28. | Gupta S, Goel M, Sachdeva G, Sharma B, Malhotra D. Autotransplantation. J Conserv Dent 2015;18:500-3. [ PUBMED] [Full text] |
| 29. | Curtis JM, Foster EC, Ananth S, Eckhardt CE, Knox J, Gonzalez Alvarez A, et al. Autotransplantation of a surgically removed canine using a customised 3D-printed surgical template. J Orthod 2020;47:82-90. |
| 30. | Anderson J, Wealleans J, Ray J. Endodontic applications of 3D printing. Int Endod J 2018;51:1005-18. |
| 31. | Lopez CD, Witek L, Torroni A, Flores RL, Demissie DB, Young S, et al. The role of 3D printing in treating craniomaxillofacial congenital anomalies. Birth Defects Res 2018;110:1055-64. |
| 32. | Krause J, Müller L, Sarwinska D, Seidlitz A, Sznitowska M, Weitschies W. 3D printing of mini tablets for pediatric use. Pharmaceuticals (Basel) 2021;14:143. |
| 33. | Derossi A, Caporizzi R, Azzollini D, Severini C. Application of 3D printing for customized food. A case on the development of a fruit-based snack for children. J Food Eng 2018;220:65-75. |
| 34. | Portanguen S, Tournayre P, Sicard J, Astruc T, Mirade PS. Toward the design of functional foods and biobased products by 3D printing: A review. Trends Food Sci Technol 2019;86:188-98. |
| 35. | Subbiah R, Hipfinger C, Tahayeri A, Athirasala A, Horsophonphong S, Thrivikraman G, et al. 3D printing of microgel-loaded modular microcages as instructive scaffolds for tissue engineering. Adv Mater 2020;32:e2001736. |
| 36. | Al-Halabi MN, Bshara N, Abou Nassar J, Comisi JC, Alawa L. Comparative assessment of novel 3d printed resin crowns versus direct celluloid crowns in restoring pulp treated primary molars. J Evid Based Dent Pract 2021;13:101664. |
| 37. | Marty M, Broutin A, Vergnes JN, Vaysse F. Comparison of student's perceptions between 3D printed models versus series models in paediatric dentistry hands-on session. Eur J Dent Educ 2019;23:68-72. |
| 38. | Alaa Eldeen R, El Dakroury A, El Sharaby F, El Beialy A, Aboulfotouh M. Evaluation of fixed mandibular retainer using 3D printed positioning tray versus direct bonding technique a randomized clinical trial. Egypt Dent J 2021;67:101-7. |
[Figure 1], [Figure 2], [Figure 3], [Figure 4]
[Table 1]
|
Search Pubmed for