“3D Printing: Transforming Smiles with Life-Changing Impact”

TRANSFORMING SMILES JOURNEY

3D printing is transforming smiles, and in the depths of my memory, a vivid recollection of childhood dental visits emerges, filled with apprehension and discomfort. The sterile scent of the clinic mingled with nervous anticipation, creating an atmosphere heavy with dread. Each appointment seemed to perpetuate a cycle of fear and unease, particularly when faced with the daunting prospect of an alginate impression for orthodontic treatment (for single tooth crossbite). The very mention of the procedure elicited shivers, as I braced myself for the inevitable discomfort and gagging that accompanied it. Despite attempts to suppress my rising nausea, each moment with the tray of viscous alginate paste heightened my sense of helplessness and dread.

Yet, in the present day, the echoes of past trauma are drowned out by the promising symphony of progress heralded by intraoral scanners. Surrounded by the comforting hum of modern technology, there is a newfound sense of hope and optimism in the dental chair. With a mix of trepidation and curiosity, I embrace the opportunity to try this innovative approach, yearning for relief from the ghosts of childhood discomfort. As the intraoral scanner effortlessly navigates my oral cavity, capturing digital impressions with precision and ease, a wave of wonder and disbelief washes over me.

The era of gag-inducing impressions fades into history, replaced by a future where patient comfort and clinical efficiency coexist harmoniously. Inspired by this newfound confidence in dental innovation, I am compelled to finally embark on the orthodontic journey that once seemed daunting and unattainable.

GLIMPSE INTO ADDITIVE MAUFACTURING

In the international press, we often encountered  headlines showcasing the utilization of 3D printing for a wide array of items, ranging from fashion wear and architectural models to armaments. The concept of ‘3D printing’ is a new development and has captivated the collective imagination of the public. The accurate term for this process is additive manufacturing, although it is also commonly known as rapid prototyping. This innovative method involves the incremental addition of material to create the final product, offering flexibility, customization, and resource optimization unmatched by traditional manufacturing techniques. 3D printing or additive manufacturing challenges conventional manufacturing and is becoming a subject of great interest in interdisciplinary dentistry .

Additive fabrication processes represent a departure from conventional subtractive methods, where material is removed from a solid block to shape the final product, or from consolidation processes where materials are fused together to form the desired object. Instead, additive fabrication builds up components from scratch, layer by layer, offering unique advantages in design complexity, waste reduction, and manufacturing flexibility.

The fusion of 3D printing technology with dentistry holds significant significance, particularly with the advancements in 3D imaging and modeling technologies such as cone beam computed tomography and intraoral scanning. With the established history of CAD/CAM technologies in dentistry, additive manufacturing is poised to become increasingly vital. Its applications span a wide array of dental procedures, including the creation of drill guides for dental implants, the development of physical models essential for prosthodontics, orthodontics, and surgical planning, as well as the manufacturing of various dental, craniomaxillofacial, and orthopedic implants. Furthermore, additive manufacturing plays a pivotal role in fabricating copings and frameworks necessary for both implant and dental restorations, underscoring its growing importance in modern dental practice.

3D PRINTED MOUTHGUARDS IN ORAL MEDICINE

Using 3D printing for drug delivery via mouthguards is a common practice in oral medicine. This innovative approach allows for the creation of customized drug delivery systems with precise design, comprehensive three-dimensional composition, and controlled release patterns. For instance, mouthguards coated with chlorhexidine have been tested to reduce oral bacteria in human subjects. Additionally, a mouthguard-shaped oral delivery device has been successfully fabricated using FDM (Fused deposition modeling) technology, enabling the controlled release of preloaded drugs into the oral cavity. These 3D printed mouthguards hold significant promise for personalized dental therapeutics by facilitating targeted drug delivery.

Orthognathic surgeries address conditions like maxillary or mandibular deformities, severe malocclusion, and cosmetic concerns. The introduction of 3D printed models has enhanced both patient communication and surgical outcomes. Traditional procedures are increasingly being supplanted by digital methods, including the creation of more precise occlusal splints that facilitate better jaw positioning during surgery . Additionally, the adoption of 3D printed osteotomy or genioplasty surgical guides has led to shorter operation times and decreased risk of nerve injuries, notably the inferior alveolar nerve.

3D PRINTING APPLICATIONS IN RESTORATIVE DENTISTRY

In the realm of restorative dentistry, a plethora of techniques have emerged for the revolutionary process of 3D printing. Among the most frequently utilized methods are those based on principles such as material extrusion, powder bed fusion, directed energy deposition, material jetting, and photopolymerization. These diverse approaches offer dental professionals a spectrum of options to craft precise and customized dental restorations, each technique leveraging unique principles to achieve exceptional results.

For instance, the Selective Laser Sintering/Melting (SLS/M) technique harnesses the power of a directed energy source, namely the laser, to fuse particles together directly on a build platform layered with deposited powder (a process known as powder bed fusion). As the metal particles coalesce under the laser’s influence, excess powder is easily removed from each layer by a simple roller mechanism. Subsequently, the build platform descends by a distance equivalent to the thickness of the newly formed layer, ready to receive another layer of powder. This iterative process ensures the gradual construction of the desired 3D object, with each layer meticulously crafted before the next is added.

Restorative Dentistry is a versatile field that extensively employs rapid prototyping technology across various applications. Leveraging a digital workflow, practitioners consistently achieve clinically satisfactory outcomes, whether it entails crafting tooth dies, wax patterns, intracoronal or extracoronal restorations, or fixed prostheses. Notably, dental materials produced via additive manufacturing often exhibit superior mechanical properties compared to traditional methods. However, the efficacy of these materials is subject to the influence of numerous factors inherent in the processing of fabricated models, patterns, or restorations.

APPLICATION OF 3D PRINTING IN ENDODONTICS

Three-dimensional printing has found applications in both nonsurgical and surgical root canal treatments. For instance, it has been explored experimentally for regenerating new teeth through stem cell delivery or dental pulp regeneration using calcium phosphate cements. Moreover, 3D printing has been employed to produce tooth models for simulating surgical procedures. For example, a tooth model was printed for the root canal treatment of a 12-year-old boy with tooth anomalies, with custom-made guides designed and printed for accessing canal spaces. The benefits of 3D printing in endodontics include enhancing access accuracy, improving the skills of non-specialists, and increasing success rates in pulpal regeneration.

Additionally, 3D printed resin teeth are valuable for educating students and general practitioners in all stages of root canal therapy. Trainees can observe various aspects such as endodontic working length, root canal morphology, and the anatomy of the apical delta, using transparent resin teeth constructed from CBCT data derived from extracted natural teeth. During canal shaping, errors associated with the use of endodontic instruments, such as gauging of preparation walls and canal transportation, can be readily observed. Importantly, 3D printed guides based on CBCT data are indispensable for locating highly calcified canals in nonsurgical root canal treatment and performing apicoectomy on posterior teeth in surgical endodontics, ultimately leading to the preservation of more teeth through root canal treatment.

3D PRINTING APPLICATIONS IN PERIODONTICS

Key 3D printing methods utilized in Guided Tissue Regeneration (GTR) and Guided Bone Regeneration (GBR) encompass droplet-based printing, micro-extrusion, and light-assisted printing. Addressing bone resorption following dental extraction poses a common challenge, prompting the exploration of various techniques, including 3D printing, to maintain adequate alveolar bone height. Park et al.  assessed the efficacy of a 3D printed PCL scaffold implanted in artificially induced saddle-type bone defects in beagle dogs, alongside β-TCP. Their findings revealed that the PCL scaffold effectively preserved physical space without eliciting inflammatory responses.

In a randomized controlled clinical trial (RCT), Goh et al.  introduced a 3D bio-resorbable PCL scaffold into fresh extraction sockets. Micro-CT and histological analysis at 6 months demonstrated reduced vertical ridge resorption with this treatment approach. Additionally, 3D printing facilitated the manufacturing of HA granules, which were deployed in alveolar sockets post-atraumatic extractions and covered with a collagen membrane . Evaluation at 8 weeks revealed complete filling of the grafted site with woven bone, accompanied by vascular neo-formation and absence of inflammatory indicators.

3D PRINTING –PROSTHODONTICS POINT OF  VIEW  

Computer-aided design/computer-assisted manufacture (CAD/CAM) made its debut in the dental sector during the 1970s, thanks to the pioneering work of Duret and Preston. Since then, it has evolved into a cornerstone technology widely embraced by dental laboratories and clinics for creating diverse dental prostheses and restorations. Across all CAD/CAM systems, three fundamental domains are present: data acquisition or scanning, computer-aided design (CAD), and computer-assisted manufacture (CAM). Various additive manufacturing (AM) techniques are employed in the fabrication of removable complete dentures, partial dentures, metal frameworks, and copings for fixed restorations.

A broad spectrum of materials, including wax, resin, metals, and, in experimental stages, zirconia, has been utilized in various additive manufacturing (AM) applications. The prevalent techniques employed encompass stereolithography (SLA), digital light processing (DLP), selective laser sintering/melting/direct metal laser melting (SLS/SLM/DMLS), and direct deposition modeling/jetting. Applications of  Stereolithography : Temporary and permanent crowns , Temporary bridges, Temporary restorations, Surgical guides and templates, Dental replica models. Fused deposition modelling : Denture flasks , Bites , Mouth guards Oral drug delivery device. Selective laser sintering: Custom-made dental implants Partial dentures. Photopolymer Jetting: Temporary crowns Dental replica models.

SUMMARY

In summary, I would like to say that 4D printing technology is advanced versio of 3D printing which enables 3D printed objects to exhibit active and responsive properties, responding to stimuli like light to alter their structure. Predicting these structural changes is achievable through simulations and analytical calculations, ensuring a reliable understanding of material behavior under external influences. Such materials hold great potential in dentistry, where their adaptive capabilities are particularly sought after.