By Dr. Mehmood Asghar
Dental caries have become a global pandemic causing the destruction of the hard and soft dental tissues. The World Health Organization estimates that over 2.3 billion adults and 530 million children worldwide are affected with dental caries. Over the previous decades, dentists used restorative materials to repair the damaged tooth structures. However, this so-called surgical-restorative model for restoring damaged tooth structures has been globally unsustainable and unaffordable (besides the limited clinical life of the restorative materials and subsequent increased risk of secondary caries further complicates matters). As a result, the current focus of scientists is to develop regenerative techniques that could aid in regenerating damaged dental tissue using tissue and genetic engineering.
Genetic Engineering to Fight Global Burden on Dental Disease
Over the last 3 decades, researchers have toiled to understand the genetic and chemical pathways involved in the regeneration of dental tissues. Previous attempts to understand the genetic hierarchy of dental tissues using mice teeth offered limited insights. However, a recent research study published in iScience has made a breakthrough discovery and has brought scientists one step closer to dental tissue regeneration (Pagella et al., 2021). For the first time, a team of researchers led by Thimios Mitsiadis, professor of Oral Biology at the University of Zurich, and Andreas Moor, professor at the Biosystems Science and Engineering Department at ETH Zurich, have mapped the entire single-cell atlas of the human teeth.
How the Study Was Carried Out
Researchers used advanced single-cell genetic sequencing technology to identify and distinguish all the component cells of the periodontium and the dental pulp. The study involved an intricate analysis of the stem cell population using RNA sequencing and comparison of the microenvironments of both the dental tissues.
The findings of their study showed significant heterogeneity between the cellular hierarchy in the dental pulp and periodontium. Interestingly, the researchers observed that the molecular signatures of the stem cells in both tissues were similar. However, the microenvironments of both tissues varied significantly. This has led the researchers to believe that the unique microenvironment of the tissues plays a pivotal role in the growth and differentiation of dental stem cells.
What is Single-cell Sequencing?
Single-cell sequencing is a revolutionary, next-generation technique that involves analyzing the differences between the genetic and protein configuration between different cells. Apart from genetic mapping of human tissues, this technology can also be used for extracting genetic information from various disease-causing bacteria (Yasen et al., 2020). In this regard, an international data coordination platform, the Human Cell Atlas, has been generating molecular maps of different humans to better understand the genomic pathways involved in the human disease process.
The single-cell sequencing technique has great clinical implications in clinical dentistry as it will aid in identifying the chemical processes and microenvironment changes that trigger dental tissue formation. Besides, it will help researchers in understanding the role played by oral pathogenic bacteria in the initiation and early diagnosis of diseases such as periodontitis and tooth decay.
The clinical implications of this study are enormous. The pulp and periodontium are the two dental tissues that are most commonly damaged during disease progression. Mitsiadis, the study’s lead researcher, believes that the findings of this study will allow dental researchers to develop techniques in the future that will pave the way for successful repair and regeneration of diseased dental tissues. The day is not far when restorative materials and dental prostheses would become a thing of the past, and tooth regeneration would become a reality.
Author: Dr. Mehmood Asghar is a dentist by profession and an Assistant Professor of Dental Biomaterials at the National University of Medical Sciences, Pakistan. Dr. Asghar received his undergraduate and postgraduate dental qualifications from the National University of Science and Technology (NUST). Currently, he also currently pursuing a Ph.D. in Restorative Dentistry from Malaysia. Apart from his hectic clinical and research activities, Dr. Asghar likes to write evidence-based, informative articles for dental professionals and patients. Dr. Asghar has published several articles in international journals.
Yasen, A., Aini, A., Wang, H., Li, W., Zhang, C., Ran, B., Tuxun, T., Maimaitinijiati, Y., Shao, Y., Aji, T., & Wen, H. (2020). Progress and applications of single-cell sequencing techniques. Infection, Genetics and Evolution, 80, 104198.