Table 1.

Significant potential of 4D printing for dentistry.

S No	Potential	Description
1	Denture removal	4D printing uses smart materials to manufacture smart dentures, arranging the occlusion forces, ages, eating, and drinking patterns. It can result from performing daily activities to develop removable prosthesis dentures. Filling materials may be adapted to constant movements and designed to overcome the inconveniences of dental practitioners' dimensional alterations using the available market materials for a long time. In addition, 4D printing can be used to improve temporomandibular joint problems. Injected or surgically implanted into the joint space might be manufactured by these intelligent materials.
2	Smart Orthodontics	4D printed parts have various features in order to adjust for dimensional variations and deceleration. This beneficial feature might assist in preventing marginal leakage. This technology can be utilised in orthodontics as functional equipment. Intelligent, mobile, and detachable appliances that maintain overtime movements might rectify dental inequalities. Various applications such as arch extension equipment and bite-raising devices might be implemented. Intelligently moving bands and wires that move teeth in the appropriate direction might improve fixed orthodontic systems with desired results over time and with atraumatic reactions in bones and periodontal ligaments.
3	Dental scaffolds	Tissue cultural engineering uses 3D printing to create scaffolds for implantation in live cells or stem cells. 4D printing can strengthen these processes since the dental scaffolds are mobile to ensure that stem cells are delivered to the target regions for specific functions. Further, 4D printing in implant dentistry might boost existing research into producing a fully 3D printed tooth, thereby allowing the coating base to move in harmony with the surrounding periodontia. In addition, this can produce a general 4D dental implant that simulates those with natural teeth with mobile characteristics. 4D printed organic scaffolds in the human body enable tissue to develop in this scaffolding and surround it, therefore essentially initiating new bone formation. Biological tissue and functioning electronics would be used to build multi-dimensional bionic organs that have improved sensory functions.
4	Surgical drill guides	4D printing is state-of-the-art technology to manufacture anything from plastic to metal with precision and speed. Dentists can design and press surgical drill guides, temporary and permanent corners and bridges, orthodontic devices, implants, and drug mouthguards in the latest advancements in 4D printing technology in dentistry and maxillofacial surgery. Several 4D printing technologies are accessible for dental usage and used to generate self-folding materials. Introducing materials such as functional items can be highly beneficial in medicine and dentistry. This method might allow physicians to modify the dental scope and give other treatment choices.
5	Enhance diagnostic and surgical processes	4D printing has made it possible for physicians to enhance their diagnostic and surgical processes, making better viewing, realistic training, and surgical planning possible. The dental practice has revolutionised this technology since it can deliver maximum precision with minimum clinical setup and fast operating time. 4D printing in dentistry is necessary and plays the leading role in facial reconstruction operations and temporomandibular problems, which necessitate surgery. In medical terms, 4D printing linked to a scanning approach used to monitor different organs' dynamic features showed significant advantages in positioning dynamic tissues during radiation treatment and monitoring thumb movements for arthroplasty.
6	Useful for the oral environment	In dentistry, 4D printing has a significant influence on many specialities because, under constantly changing circumstances of temperature and humidity, the technology can generate dynamic and adaptive materials that are useful in the oral environment. Unwanted dimensional changes, heat instability, polymerisation reduction, and microleakage are contemporary dental issues that may be addressed with 4D printing technology. For dental restorative materials, 4D printing can be employed. The biomechanical qualities of dentures have long been a major subject; strength, colour stability, adherence, durability, and insufficiency are essential features of dental fillings.
7	Specific patient dental prosthesis	Objects self-folding may be used for dental, surgical, and medical functionally. Given the extensive use of such materials, there is a major advancement in dentistry. The prosthesis may be set to adjust for age and everyday activities, designed and adjusted for specific patients. Prosthetic cardiac valves have been conceived in line with blood flow with programmed motion behaviour. There is a rise and a reduction of blood via the valve depending on the blood pressure. In contrast to conventional 3D valves, 4D valves can handle blood pressure fluctuations.
8	Devices adjusted as per patient's mouth	4D printing may be applied in dentistry in various applications based on its mobile nature and can become helpful. The mouth constantly changes so that 4D print items may be folded and kept folding continuously. 4D printing provides items that can be used for a positive effect. This may be converted into a joint implant in orthopaedics, where mobile discs replace standard plastic discs to act in the cushions of knees, hips, ankles, and shoulder joints. For the health business, shape memory polymer looks like customisable forms.
9	Replace lost tooth structure	The oral environment is challenging to replace lost tooth structures, both in its dynamic character and functional and balance factors. Materials breakdown usually results in dimension changes on the edges leading to instability or complete loss of dental fillings. The result of 4D printing can be materials with a constant adaptation to self-folding, that is to say, materials that can move towards the peripheries to prevent microleakage or marginal overhangs. 4D printing enabled the improved visualising of deep structures such that possible problems, including longer surgical time and resultant infection or blood loss, were minimised during surgery. This technology contributes to the manufacture of detachable dentures and prostheses in the simple aesthetic and restaurant daily job.
10	Produce tissue-like structure	4D printing finds uses in organ printing via individual production or layers of cells and biomaterials that produce a tissue-like structure. It might assist in overcoming the enormous deficit in donor organ production once it occurs from childhood. Further, 4D printing is also possible to manufacture individualised medications in novel formulations, such as multilayer, multi-reservoir, microcapsules, nanosuspensions, and multilayer drug delivery systems, which comprise several active substances. 4D printing is carried out utilising organic components, including stem cells, proteins, and factors for growth. In the future, doctors may replace sections of the body like tissues, arteries, and organs easier after using such materials has been completely established for 4D printing.
11	Smart dental implants	4D printing can be used to produce smart implants quickly. The appropriate implanter design layer is produced by concentrating a high-power laser beam that fuses metal particles to a powder bed without any post-processing processes. Other dental uses include crown coping, frameworks for partial dentures, surgical tools, oral and maxillofacial implants, and forensic odonatological and simulation models for educational purposes. In healthcare, 4D printing offers enormous promise. Biocompatible materials like hydrogels and polymers might be utilised during the 4D impressions. In 4D printed orthodontic devices, the position of the teeth could vary by undergoing a regulated automatic self-folding motion which can be undertaken by using this technology.
12	Sophisticated dental surgery	4D printed models allow more sophisticated dental surgery. This also benefits in as many sectors, from medical to electronics and much beyond. 4D printing focus adds a more intuitive, intelligent aspect to the manufacturing. 4D printing is divided into medical and research models, operating manuals, and patient-specific implants based on their use. 4D printing technology's capacity to produce smart health models will significantly alter the medical sector and assist in expanding this area throughout the predicted period. Our digital future includes other diagnostic instruments and treatment methods that increase and extend the use of speciality.
13	Human bone structure	A new development in 4D bioengineering technology allows the human bone structure to be shaped. 4D printing may also modify tissue of the nerve, skeletal muscles, and skeleton ligaments which can print form-changing materials. Due to the growing availability of print personalisation, the medical and health sectors actively explore the areas of 4D printing. 4D printing includes implants, artificial bones, artificial organs, and medical assistance. 4D printing has emerged as an upgrade in medicine, making it an anticipatory alternative. Active materials such as memory polymers are utilised to generate a solid form that changes its current shape and returns to the original form if activated in a regulated fashion. This is due to the chemical interaction of the ingredients employed in production. After printing, the material responds to the environment, such as heat, humidity, and other factors, and changes its shape, size, etc., which is a programmable substance.
14	Successful patient treatment	4D printed models may be customised according to the patient's disease so that patient treatment could become efficient and successful. 4D technology has demonstrated its capacity to revolutionise the dental sector in developing smart models. The primary use of the therapeutic medication supplied in a specific human body position is targeted drug supply. 4D printed devices can transport medicinal medicines where the exact triggers are activated. Now, 4D Printing's core notion retains 3D printing intact and adds a whole new element. With 4D Printing, we can alter the structures that have been produced throughout time. 4D printing is utilised on 3D printers fed with some smart material. This intelligent substance is a memory polymer hydrogel or form that helps perform the various intended functions.
15	Improve quality, efficiency and performance	4D printing technology extends 3D printing and provides increased quality, efficiency, and performance. Due to strong rivalry, the desire to lower production and processing costs should be a major driver in speeding up the global 4D printers market in the future years. Numerous technologies are now combined to contribute to 4D printing material performance breakthroughs. The technologies include materials science, 3D/4D multi-material printing, and novel optimisation and simulation software capabilities. These functions have enabled a variety of materials to be fully programmed to alter appearance, form, or other qualities as required.