Dental Hypotheses

PERSPECTIVE
Year
: 2021  |  Volume : 12  |  Issue : 1  |  Page : 47--49

Biodontics: A New Paradigm in Dentistry


P. Aravind Kumar, Keerthi K.L, Jayasri D, Tejaswini B 
 Department of Periodontics, St Joseph Dental College, Duggirala, Eluru, Andhra Pradesh, India

Correspondence Address:
Professor P. Aravind Kumar
Department of Periodontics, St Joseph Dental College, Duggirala, Eluru, Andhra Pradesh
India

Abstract

Regeneration can be done by stem cells derived from exfoliated deciduous teeth. Teeth that are formed from stem cells are denoted to as “tissue-engineered” teeth. In dentistry, mesenchymal stem cell-like populations were identified from both dental and nondental tissues has offered sensational opportunities for the application of tissue engineering as well as gene based therapies. These methods have the possibility to lead toward the growth of new approaches for regenerative periodontal therapy. Biodontics is the practice of dentistry that leads to the promotion of repair, restoration, and replacement of dental, oral, and craniofacial structures with natural biological materials of cellular source and it will substitute xenodontics, the practice of dentistry that uses external materials (e.g., metals and plastics) for this purpose.



How to cite this article:
Kumar PA, K.L K, Jayasri, Tejaswini. Biodontics: A New Paradigm in Dentistry.Dent Hypotheses 2021;12:47-49


How to cite this URL:
Kumar PA, K.L K, Jayasri, Tejaswini. Biodontics: A New Paradigm in Dentistry. Dent Hypotheses [serial online] 2021 [cited 2021 Sep 19 ];12:47-49
Available from: http://www.dentalhypotheses.com/text.asp?2021/12/1/47/310532


Full Text



 Introduction



Loss of teeth due to trauma, hypoplasia or periodontal disease can be detrimental. Various grafting measures have been attempted, but restricted sources and unstable prognosis have limited their use.[1] The restoration of missing or damaged teeth, by fixed or removable prosthesis or dental implants, may not provide ideal replacements due to less than ideal function or immunological rejection. Hence, the development of a tooth with natural materials is a goal for tissue engineering.

Biodontics is the developing branch of dentistry that repairs, restores, and replaces dental, oral, and craniofacial structures with natural biological materials of cellular origin and it will replace xenodontics, the practice of dentistry that uses foreign materials (e.g., metals and plastics) for this purpose.

A biological tooth (biotooth) that is made from the patient’s own cells and grows in its intended location should be the best choice for treating the tooth loss. A biotooth is a genetically engineered tooth created from stem cells. The stem cells for a biotooth can be obtained from a primary tooth, an unerupted tooth bud, a third molar, chord cells (blood), and tissue-engineered cells (adipose tissue and hair follicle). These are the cells that regenerate via mitotic cell division and differentiate into specialized cell types. Stem cells have the remarkable potential to develop into many different cell types in the body during early life and growth on simulation.

These cells have unique properties of the following:Self-renewal: Stem cells can renew themselves almost indefinitely, which is also known as proliferation.Differentiation: Stem cells have the special ability to differentiate into cells with specialized characteristics and function.Unspecialized: Stem cells are largely unspecialized cells, which then give rise to specialized cells.

Types of Stem Cells

Based on their origin, stem cells are categorized either asEmbryonic stem cells (ESCs) or as postnatal stem cells.Somatic stem cells or adult stem cells.

ESCs are best derived from 2- to 11-day-old embryo called blastocyst. ESCs are considered as immortal as they can be propagated and maintained in an undifferentiated state indefinitely. The therapeutic benefit of these totipotent cells is curtailed by moral and ethical concerns as extracting stem cells from an embryo destroys the embryo itself. Owing to these shortfalls, ESCs remained only as a platform for research.[2].

Adult stem cells are multipotent, that is, they are capable of differentiating into more than one cell type but not all cell types. Moreover, they have plasticity, that is, their ability to expand beyond their recognized potential irrespective of the parent cell from which they are derived. Adult stem cells can be hemopoetic stem cells or mesenchymal stem cells (MSCs).

Tissue engineering is a multidisciplinary field, which involves the application of the principles and methods of engineering and life sciences to help in the development of biological substitutes to restore, maintain, or improve the function of damaged tissues and organs.

The three major factors that play a role in tissue engineering are as follows:Morphogenic signals: Growth factors and differentiation factors play an important role in multiplication and differentiation of stem cells. Bone morphogenic proteins (BMPs), which are the multifunctional growth factors, belong to the transforming growth factor beta superfamily and cytokines of the immune system play a vital part in organogenesis, for example, in differentiation of dental pulp stem cells (DPSCs) into odontoblasts, which is the main requirement of teeth tissue engineering.Responding stem cells: They are initially attained from the patient and preserved under good conditions to uphold their distinctive capability to differentiate into a wide-ranging cells, are later coaxed in the laboratory to transform it into a tooth bud.Scaffold: It provides a mechanical support to the cells required for regeneration of any tissue and it has to be biodegradable and speed of degradation has to coincide with the speed of tissue development. The scaffold has to be permeable, which aids in cell nutrition, proliferation, and migration for tissue vascularization as well as formation of new tissues. Mechanical stability of the implant is improved by the porous surface by the mechanical interlocking between the scaffolds and surrounding tissues.[3]

Transformation from Xenodontics to Biodontics

Biomembrane scaffolds are seeded with stem cells implanted in the jaw at socket or prepared site. (BMSC and DPSC) scaffold may be collagen hydrogel, chitosan, poly-L-Lactic acid, poly-L-Glycolic acid, and HA+TCP.Scaffold implantation done (orthotopic or ectopic) by soak system, low pressure system, pipette system, or syringe system. Osteogenic differentiation takes around 2 weeks.Osteogenic differentation-SDF1 and BMP 7 plays role in angiogenesis.Positional information and tooth morphogenesis (barx1, 3-D bioprinting, EDA, TRAF6 play role.Bone regeneration and periodontal ligament regeneration.

Biotooth Replacement

This procedure is a better alternative than traditional teeth replacement methods and it involves regrowing or reconstruction of a tooth in the mouth. However, the problem with this procedure is that it needs the right tooth shape. Following are the ways in constructing a biotooth:Reconstruct the mature tooth as it appears in the mouth.Reproduce the embryonic development in the mouth.Induce a third dentition.Create a tooth-shaped scaffold, place some cells in them and wait for the cells to grow.[4]

Of the options present above, only two are being tried in the conceptual stage and the other two are still being studied.

Reconstruct the mature tooth as it appears in the mouth: The four components in a tooth- the crown, dental pulp, enamel, and root- are separately constructed from the materials and appropriate cells.

The drawback of this procedure is that the process has a high level of technical difficulty. The advantages, on the other hand, include having a high level of control on the process and the possible automation and scale-up.[5]

Inducing a third dentition: This prospect has been around for quite a while, and there is an appealing proposition for this. Primarily, it works by adding molecules with either of the two earlier dentitions in development of initiating the de novo of the tooth posttooth loss. But there are two problems encountered: genes involved in induction of tooth initiation have a part in bone development, and other cellular process and cells found in the teeth are not present in the adult jaw, therefore, the molecules have nothing to act upon.

Create a tooth-shaped scaffold, place some cells in them, and let the cells grow: This procedure is highly successful and uses tissue engineering technique. It involves seeding of biodegradable scaffolding with cells, and generation of these tissues will mold on to the shape of the scaffolding. There are various uses of these scaffolds, and may even be able to regenerate teeth and other organs, but this theory is still under investigation.

Applications in dentistry: In the field of dentistry, stem cell research is directed toward achieving the following; regeneration of damaged coronal dentine, pulp, resorbed roots, cervical or apical dentine, and periodontal ligament; besides plugging of perforations, repair of craniofacial defects, and whole tooth regeneration.

DPSCs represent a kind of adult cell colony, which has the potent capacity of self-renewal and multiline differentiation. These stem cells seem to be the source of odontoblasts that contribute to the formation of dentin pulp complex. Some studies have proved that DPSCs are capable of producing dental tissues in vivo including dentin, pulp, and crown-like structures, where as other investigations suggested that these stem cells can bring about formation of bone-like structures. Theoretically, a biotooth made from autogenous PSCs should be the best choice for clinical tooth reconstruction.[6]

Granthos et al.[7] demonstrated, both in vitro and in vivo, in animals that DPSCs were capable of forming ectopic dentin and associated pulp tissue.

Batouli et al.[8] used an in vivo stem cell transplantation system to investigate differential regulation mechanisms of bone marrow stromal stem cells (BMSCs) and DPSCs. DPSCs were found to be able to generate a reparative dentine-like tissue on the surface of human dentin in vivo.

Regenerating periodontal ligament: Periodontal regeneration has always remained a challenge, as it consists of cells that give rise to both hard and soft tissues. Shi et al.[9] (2004) used autologous bone marrow (MSC) in combination with allocollagen to regenerate periodontal ligament in experimental grade III defects in dogs. One month after implantation, there was regeneration of cementum, periodontal ligament, and alveolar bone. Hasegawa et al.[10] demonstrated that autologous periodontal ligament cells cultured in vitro were successfully reimplanted into periodontal defects in order to promote periodontal regeneration in dogs and a subsequent study confirmed this evidence in humans.

 Conclusion



Although such bioengineered teeth have been nothing more than a dream for many centuries. In the near future, dental stem cells will probably be able to grow new teeth and jawbone, thereby enabling unlimited therapeutic applications. However, issues involving in the reconstruction of a biotooth regarding the shape determination, size control, availability of dental epithelium, directional growth and eruption, and graft rejection in the jaws remain to be resolved. Various challenges must be overcome before this novel therapy can be translated from laboratories to clinics. Collaboration between basic scientists and clinicians is required to achieve this goal. Advancement in the field of research has revealed a ray of hope to dentistry for the generation of a biotooth in humans that will improve quality of life in the upcoming years.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Rossomando EF. Prosthodontics and implants: from xenodontics to biodontics. Compend Contin Educ Dent 2007;28:418-20.
2Shapiro SS, Waknitz MA, Swiergiel JJ, Marshall VS, Jones JM. Embryonic stem cell lines derived from human blastocysts. Science 1998;282:1145-7.
3Barrilleaux B, Phinney DG, Prockop DJ, O’Connor KC. Review: ex vivo engineering of living tissues with adult stem cells. Tissue Eng 2006;12:3007-19.
4Chaudhary G, Chaudhary N, Chaudhary A. Biotooth − A dream or reality. Ann Prosthodont Restor Dent 2015;1:16-19.
5Ohazama A, Modino SAC, Miletich I, Sharpe PT. Stem-cell-based tissue engineering of murine teeth. J Dent Res 2004;83:518-22.
6Murray PE, Garcia-Gadoy F, Hargreaves KM. Regenerative endodontics: A review of current status and a call for action. J Endod 2007;33:377-90.
7Granthos S, Brahim J, Fischer W, Cherman N, Boyde A, Den Besten P et al. Stem cell properties of human dental pulp stem cells. J Dent Res 2002;81:533.
8Batouli S, Miura M, Brahim J, Tsutsui TW, Fisher LW, Gronthos S et al. Comparison of stem cell mediated osteogenesis and dentinogenesis. J Dent Res 2003;82:976-81.
9Shi S, Bartold PM, Miura M, Seo BM, Robey PG, Gronthos S. The efficacy of mesenchymal stem cells to regenerate and repair dental structures. Orthod Craniofacial Res 2005;8:191-9.
10Hasegawa M, Yamato M, Kikuchi A, Okano T, Ishikawa I. Human periodontal ligament stem cell sheets can regenerate periodontal ligament tissue in athymical rat model. Tissue Eng 2005;11:469-77.