Single-Cell Transcriptomic Profiling of Human Dental Pulp in Sound and Carious Teeth: A Pilot Study

A comprehensive understanding of dental pulp cellular compositions and their molecular responses to infection are crucial for the advancement of regenerative dentistry. Here, we presented a pilot study of single-cell transcriptomic profiles of 6,810 pulpal cells isolated from a sound human maxillary third molar and three carious teeth with enamel and deep dental caries. We observed altered immune cell compositions of the dental pulp in deep, but not enamel ones. Differential expression analysis revealed up-regulation of several pro-inflammatory, anti-inflammatory, and mineralization-related genes in the immune and stromal cells of the deep dental caries. Making use of an algorithm for predicting cell-to-cell interactions from single-cell transcriptomic profiles, we showed an increase in cell-cell interactions between B cells, plasma cells and macrophages, and other cell types in deep dental caries, including those between TIMP1 (odontoblasts)—CD63 (myeloid cells), and CCL2 (macrophages)—ACKR1 (endothelial cells). Collectively, our work highlighted the single-cell level gene regulations and intercellular interactions in the dental pulps in health and disease.

The Application of Zirconia in Tooth Defects

Dental caries is among the most prevalent chronic diseases of childhood, affecting larger part of children and adults. Non-treated enamel caries can lead to destruction and then spreads into the underlying softer and sensitive dentine layer. Dental restorative materials are applied to treat and reconstruct damaged teeth clinically and recover their functions. Currently, there are various dental restorative materials available, and many appropriate materials are used to restore dental carious teeth. The applicability of biomimetic principles can elicit innovations in restorative dentistry for tooth conservation and preservation. There are three types of materials commonly used in dental restorations: resin, alloys, and ceramic. During the past decade, zirconia-based ceramics have been successfully introduced into the clinic due to acceptable biocompatibility, lower price compared with gold restorations, and better appearance than traditional metal-ceramic restorations. Recently, zirconia restoration is an acceptable treatment option in restorative dentistry and a developing trend in esthetic dentistry.

Histological Aspects Regarding Dental Pulp of Diabetic Patients

Background: The possible histological changes in dental pulp in teeth of diabetic patients are important to be understood, as the clinician will consider the best treatment choice for those teeth, especially if they are affected by decay. The aim of this paper is to assess if there are effects of diabetes-associated hyperglycemia on the nervous and vascular system of the dental pulp. Methods: Twenty-three dental pulp specimens of patients aged 36–70 years old were analyzed. All patients had been diagnosed with type 2 diabetes for at least 5 years. Results: Most of the patients had poorly controlled hyperglycemia, deep caries, but no clinical signs of pulpitis. The histological aspects of pulp specimens included frequently seen inflammatory infiltrate, degeneration of the nerves, thickened blood vessel walls, pulp sclerosis and frequent pulp calcifications, and even small necrotic areas. Conclusion: The analyzed dental pulp specimens of carious teeth of type 2 diabetic patients show fibrotic transformation of the dental pulp, with the presence of calcifications, arteriosclerosis and inflammatory infiltrate. In this situation, the attitude of the dentist in pulp vitality preservation in the case of carious teeth of diabetic patients should be limited.

POS0791 DOSE-DEPENDENT RELATIONSHIP BETWEEN HISTORY OF DENTAL CARIES AND INCREASED RISK OF NEWLY-ONSET SYSTEMIC LUPUS ERYTHEMATOSUS: A NATIONWIDE POPULATION-BASED COHORT STUDY

Background:The relationship between oral bacterial invasion caused by periodontal pathogens and risk of systemic lupus erythematosus (SLE) has been identified. However, there is a lack of knowledge on the relationship between carious lesions and risk of SLE, as well as longitudinal studies on the effect of restorative materials on SLE.Objectives:This study investigated whether patients with history of dental caries are associated with an increased risk of newly-onset systemic lupus erythematosus (SLE).Methods:A total of 541,461 carious patients and 258,918 controls without carious teeth were enrolled between 1997 and 2013 from the National Health Insurance Research Database. Subgroup analyses were conducted based on restorative materials included amalgam, resins or both. Cumulative incidences and hazard ratios (HRs) of developing SLE were derived after adjusting for age, gender, comorbidities and co-medications in a multivariable model.Results:The risk of SLE was significantly higher in carious patients (HR = 1.984, 95% = 1.652-2.382) compared to controls. Dose-dependent relationship between caries and risk of SLE was identified. The risks of SLE were higher among those who had over 11 dental visits (HR = 2.525, 95% C.I = 1.859-3.429), followed by those with 3-10 dental visits (HR = 1.863, 95% C.I= 1.356-2.543), then those with 1-2 visits, and were higher among those who had over 5 carious teeth extractions (HR = 1.877, 95% C.I= 1.186-2.970), followed by those with 1-4 carious teeth extractions (HR = 1.363, 95% CI = 1.167-1.593), then those without extraction. The risk of SLE among different restorative materials, including amalgam or resins, for caries management, were not significantly different.Conclusion:Patients with caries were associated with higher SLE risks. The relationship between caries and risk of SLE was dose-dependent, regardless of used restorative materials.Disclosure of Interests:None declared

Assessing the viability of carious lesions in human identification using STR typing

Human teeth have become a prominent source of DNA for human forensic identification as their biological structure is highly resistant to extreme conditions. Previous forensic identification was mainly dependent on the pulp and the other hard tissues of intact teeth. However, there is high likelihood that only carious teeth can be available for forensic analysis. This study aimed to validate the use of the carious part of the teeth for forensic identification and to compare two DNA extraction methods-the operative technique with the cervical cut technique for human identification using STR typing. The reliability of STR markers in carious part of the teeth was evaluated in 120 carious teeth (60 dental pulp and 60 dentinal carious tissues, respectively) with considerable coverage of gender type and age range to avoid false exclusions. The study was performed on genuine data set where samples have been extracted by proficient dentist during the treatment operation and collected for further analysis. Complete DNA was extracted and the corresponding human identification profile was obtained using the GoldenEye™DNA ID system 20A kit. The operative technique showed a conservative approach to the sampling of carious tissues and allowed safe access to collect carious tissues, whereas the cervical cut technique permitted access to the root canals and complete sampling of the pulp tissues. The findings indicated that there was no significant association between the cervical cut and operative cut techniques ( p = 0.165). In addition, there was no statistically significant association between the various teeth types and the obtained profiles observed. The operative technique, by drilling holes on the defected surface of carious human teeth and gentle hand excavation of carious tissues, was indicated to be very efficient, preserving, time-saving, and cost-effective in the recovery of human DNA from carious teeth. The result gives new insights that the carious tissues of human carious teeth might be as valid as the healthy teeth for forensic human identification.

Dental caries in South African fossil hominins

Once considered rare in fossil hominins, caries has recently been reported in several hominin species, requiring a new assessment of this condition during human evolution. Caries prevalence and location on the teeth of South African fossil hominins were observed and compared with published data from other hominin samples. Teeth were viewed macroscopically, with lesion position and severity noted and described. For all South African fossil hominin specimens studied to date, a total of 10 carious teeth (14 lesions), including 4 described for the first time here, have been observed. These carious teeth were found in a minimum of seven individuals, including five Paranthropus robustus, one early Homo, and one Homo naledi. All 14 lesions affected posterior teeth. The results suggest cariogenic biofilms and foods may have been present in the oral environment of a wide variety of hominins. Caries prevalence in studied fossil hominins is similar to those in pre-agricultural human groups, in which 1–5% of teeth are typically affected.

Oral health of prosthetic rehabilitated patients with schizophrenia

Introduction/Objective. Factors such as nature of psychiatric disorder, length of hospitalization and oral-side effects of psychotropic medications may considerably contribute to high prevalence of oral diseases among people with schizophrenia, and a consequent need for prosthetic rehabilitation. The aim of this study was to ascertain the oral health level of prosthetic rehabilitated patients with schizophrenia and to consider their needs for future improvement of prosthetic rehabilitation. Methods. The study group comprised 52 patients with schizophrenia, hospitalized at the Clinic for Mental Disorders ?Dr Laza Lazarevic? Belgrade. The control group comprised 52 patients with no psychiatric medical history, treated at the School of Dental Medicine, University in Belgrade. The oral health indices (DMFT index, CPITN and OHI-S), socio-demographic characteristics, smoking habits, oral hygiene habits and previous dental visits were registered in both groups, as well as medical characteristics of the primary disease in the study group patients. Results. Fifty percent of the study group patients had partial mobile dentures, while almost 30% had fixed dentures, in opposite to the control group patients who prevalently had fixed dentures. In both groups of patients, a statistical significance was observed between partial mobile and fixed dentures wearers, in terms of DMFT index, carious teeth, CPI modified and OHI-S. Similarly, a statistically significant difference between groups was observed concerning fixed dentures in terms of carious teeth, filled teeth, CPI modified and OHI-S. Conclusion. Multidisciplinary approach is needed for complete oral and prosthetic rehabilitation of this group of psychiatric patients.

Characteristics of Trace Element Balance in Children with Pollution-Related Dental Diseases

Summary. Introduction: The necessity to assess, prevent and correct element-dependent diseases, increase the level of safety, predict and reduce the risk of exposures to industrial contaminants in the development of dental diseases in the child population is an important and promising area of modern hygiene. The objective of our study was to establish concentrations of trace elements in dental tissues of children exposed to various levels of industrial pollution. Materials and methods: We used atomic absorption spectrophotometry to measure 13 trace elements in extracted healthy and carious primary teeth in two groups of children aged 7–11. The first group consisted of 56 children living in the area with a significantly high level of anthropogenic burden (Caveraged total = 1.17 units) and a high prevalence of caries (86.9 %) while the second group consisted of 68 children living in the area with a relatively high level of anthropogenic burden (Caveraged total = 0.68 units) and a mean prevalence of caries (77.1 %) according to WHO criteria. Results: Our findings indicate that accumulation of toxic microelements in hard dental tissues of children in the first group was higher than in children of the second group: concentrations of lead, bismuth, cadmium and strontium were 2.6, 1.8, 2.5, and 1.2 times higher, respectively. We also observed higher accumulation of environmental toxicants in carious teeth compared to healthy ones. Thus, lead, cadmium and bismuth levels in carious teeth were 3.04, 1.2 and 3.13 times higher than in healthy teeth, respectively, while the level of strontium was, on the opposite, 2.5 times lower. Conclusions: The study revealed specific features of the interaction of essential trace elements in children in the form of antagonistic effects between cadmium and zinc, copper and manganese, and synergism in the content of copper, iron, nickel, zinc, and cobalt in healthy teeth, the mechanism of which is based on competition for a bond with a carrier substance and replacement of one element with another. In addition, we established that changes in the microelement balance in the hard tissues of healthy and carious teeth are not unidirectional in nature, thus reflecting complex interactions between the child’s organism and anthropogenic factors. The results proved that accumulation of toxic trace elements in hard dental tissues promotes caries development and causes a sharp decrease in the content of essential trace elements, especially chromium, manganese, iron, and copper. The study showed that hard dental tissues are a depot for lead, cadmium, bismuth, and strontium in children environmentally exposed to high levels of industrial chemicals. Features of developing an imbalance of biotic concentrations of essential elements and accumulating toxic microelements in children with pollution-related tooth pathology were also established.