Decellularisation of the Dental Pulp for Use as a Scaffold in Regenerative Endodontics

Background: Endodontic management of immature necrotic permanent teeth is currently undergoing a paradigm shift from the conventional apexification and apical plug techniques to biological based regenerative procedures. The shift towards a tissue engineered clinical based procedure is highly attractive. However, the ideal scaffold to support pulp-dentine complex regeneration is yet to be identified. Aim: The primary aim of this work was to develop, characterise and assess the biocompatibility of an acellular extracellular matrix scaffold developed through decellularisation of rat and human dental pulp tissues. The secondary aim was to assess the ability of the scaffold to support human dental pulp stem cells attachment, viability, and differentiation. Methods: Following ethical approval, rat and human dental pulps were retrieved and decellularised. The efficiency of the decellularised protocol was assessed using histology and immunohistochemistry staining methods, scanning electron microscopy, and DNA quantification assays. Contact and extract cytotoxicity assays were performed to determine the biocompatibility of the developed scaffold. Decellularised scaffolds were recellularised with human dental pulp stem cells and cell viability was assessed, for up to 14 days, in culture. Expression of odontoblastic markers and molecular proteins within the recellularised scaffold were also investigated. Quantitative data were analysed using Student’s t-test and one-way analysis of variance using GraphPad Prism(Version 6). Results: Assessment of decellularised scaffolds revealed an acellular matrix with preservation of the connective tissue architecture and composition. Acellular scaffolds were biocompatible with normal cell growth in direct contact with the acellular scaffold. No difference in cellular activity was found following incubation in acellular scaffold extracts (p> 0.05). Live/Dead® confocal imaging showed high majority of viable cells. Furthermore, the scaffold was able to support human dental pulp stem cells viability and attachment following recellularisation. Immunolabelling of dental pulp stem cells within the recellularised scaffold revealed a positive expression against several tested odontoblastic markers and molecular proteins. Conclusion: The decellularisation protocol used showed promising results following decellularisation of rat and human dental pulp tissues in terms of developing an acellular biological scaffold with preserved extracellular structural components required for tissue specific regeneration

Tooth auto-transplantation: A bibliometric analysis of the top 100 most-cited articles

Background/Aim: Tooth auto-transplantation has recently gained high clinical acceptance. The aim of this study was to identify the top 100 most-cited articles regarding tooth auto-transplantation, to analyse multiple citations and publication metrics and to outline the historical scientific advancements in this field. Materials and Methods: An advanced search of the Clarivate Analytics' Web of Science ‘Core Collection’ and Elsevier's Scopus databases utilising specific keywords related to tooth auto-transplantation between 1971 and 2021 was performed. The retrieved articles were ranked in descending order based on their Web of Science citation counts and further cross-matched with citation data from Scopus. The extracted data included citation counts, citation density, level of evidence, year of publication, contributing authors names and institutes, corresponding author's address, journal of publication, journal local citations index, cumulative growth index, keywords and keywords Plus. Data analysis was performed using descriptive statistics and graphical mapping. Results: A total of 1290 articles were retrieved. The top 100 most-cited articles received a total of 4899 (Web of Science) and 5250 (Scopus) citations. Among these, cohort studies (29%) and case series (18%) were the most common study designs. Scandinavian countries produced major contributions in defining the top 100 most-cited articles and ranked within the top 5 countries based on the number of publications and citations per year. The greatest contributing authors were Schwartz O (n = 12), Andreasen JO (n = 8) and Paulsen HU (n = 6), and they were affiliated with Copenhagen, Denmark. The top contributing journals were American Journal of Orthodontics and Dentofacial Orthopedics, International Journal of Oral and Maxillofacial Surgery, Oral Surgery Oral Medicine Oral Pathology Oral Radiology, European Journal of Orthodontics, Dental Traumatology and Journal of Oral and Maxillofacial Surgery. Conclusion: This bibliometric analysis revealed a large geographical scientific interest and broad development in the field of tooth auto-transplantation spanning multiple dental disciplines.Open Access funding provided by the Qatar National Library

Radiographic assessment of endodontic mishaps in an undergraduate student clinic: a 2-year retrospective study

Objectives. The aim of this study was to compare the occurrence of instrumentation and obturation related endodontic procedural mishaps following the use of either, stainless steel hand or engine-driven rotary instrumentation techniques. Methods. From a computerized hospital database, a total of 730 dental patient records who had received endodontic treatment by undergraduate dental students between August 2018 to September 2020 were retrieved. The inclusion criteria were primary (non-surgical) endodontic treatment on permanent teeth with complete radiographic records. Following record screening, a final sample of n = 475 dental records were included. Radiographic records were evaluated for both instrumentation and obturation related mishaps. The data was analysed using multiple logistic regression analysis (α = 0.05). Results. Engine-driven rotary instrumentation resulted in a significant decrease in the overall occurrence of instrumentation related endodontic mishaps by 40% compared to hand instrumentation (Odds Ratio = 0.59 [0.36–0.97], p = 0.04). In particular, rotary instrumentation decreased ledge formation, perforation and obturation related mishaps, with minimal effect on the limitation of zipping. Conclusion. The use of rotary instrumentation techniques may reduce the incidence of instrumentation and obturation endodontic mishaps in the undergraduate dental clinic.Princess Nourah bint Abdulrahman University Researchers Supporting Project number (PNURSP2022R162), Princess Nourah Bint Abdulrahman University, Riyadh, Saudi Arabia

Propolis use in dentistry: A narrative review of its preventive and therapeutic applications

Propolis is a resinous substance produced naturally by bees, and it consists of the exudates of plants mixed with enzymes, wax, and pollen. Propolis continues to gain considerable scientific interest due to its potential health benefits. The modern-day use of propolis in pharmaceutical preparations, such as toothpastes, mouthwashes, chewable tablets, mucoadhesive gels, and sprays, is increasing. However, the effectiveness of using propolis-containing pharmaceuticals in dentistry is not clear. The present paper aims to review the literature on the dental applications of propolis in preventive dentistry, periodontics, oral medicine, and restorative dentistry and discuss its clinical effectiveness. A literature search was conducted using Scopus, PubMed, and Web of Science databases. In total, 104 studies were included, of which 46 were laboratory studies, 5 animal studies, and 53 human clinical studies. Overall, the laboratory studies revealed a range of antimicrobial effects of propolis on oral pathogens. Clinical investigations of propolis in biofilm and dental caries control as well as adjuvant periodontal therapies reported positive outcomes in terms of plaque control, pathogenic microbial count reduction, and periodontal tissue inflammation control. Additional investigations included the use of propolis for the management of recurrent aphthous stomatitis, oral mucositis, and cavity disinfection after caries removal as well as the development of a range of restorative dental materials. Based on the reported outcomes of the studies, the clinical usage of propolis has potential. However, the majority of the evidence is derived from studies with flaws in their methodological design, making their results and conclusions questionable. As a consequence, properly designed and well-reported clinical studies are required to affirm the effectiveness of propolis for dental applications. Additionally, the safety of propolis and the optimal concentrations and extraction methods for its clinical use warrant further investigation. Utilisation of standardised propolis extracts will help in quality control of propolis-based products and lead to the achievement of reproducible outcomes in research studies

Development of Self-Regulation amongst Dental Students in Problem-based Learning Curricula: A Qualitative Study

To explore the value of problem-based learning in the development of self-regulation amongst undergraduate dental students. A qualitative approach using focus groups was used to explore the perceptions and experiences of the participants regarding the role of problem-based learning (PBL) in promoting self-regulation in undergraduate dental education. The study was carried out at a newly established dental institution in Qatar. Purposive sampling technique was used to recruit the participants. Invitations to potential participants were sent by e-mail through appropriate professional channels. All focus groups were transcribed verbatim, and data were imported into NVivo 12 and analysed thematically. A total of five focus groups were conducted with 37 participants which included 27 females and 7 males from two different cohorts. Participants expressed their views on a range of issues related to the self-regulation in problem-based learning and also provided recommendations to enhance the learning experiences of students. PBL was perceived to be an appropriate and effective strategy to support student autonomy in construction of knowledge and developing problem solving and interpersonal skills. However, the workload of the students can impact adversely on their motivation and time management skills. This study provides useful insights into the concept of self-regulation in problem-based learning environments as perceived by the stakeholders at a newly established dental institution. The findings of this study may offer clarity on how problem-based learning can be best utilised to promote self-regulation in undergraduate dental education.Open Access funding provided by the Qatar National Library

Development of professional identity among dental students - A qualitative study

The study explored dental students' perception of their professional identity (PI) development at a newly established dental college with a problem-based learning (PBL) curriculum. Qualitative methods based on focus groups were used for data collection. The conceptual framework of the study was informed by a subject-centered sociocultural approach to PI development. Purposive sampling was used to collect data from five focus groups of undergraduate dental students to gain a deeper understanding of their PI development in a PBL environment. Out of a total of 38 dental students in years 2 and 3, 34 students (89.47%) participated in the focus groups. A theory-driven thematic analysis was used to dissect the views and experiences of the participants to explore factors contributing to PI development in the early years of the program. At an individual level, PBL was seen to be appropriate for PI development. However, some participants placed more emphasis on practical training in operative dental skills. Relational sources especially role modeling by the PBL facilitators and faculty staff were identified as a key factor to nurture PI development. Mixed views were observed on the value of PBL to enhance team-working skills. The participants also identified challenges of PBL and provided recommendations on further improvements to enhance the learning experiences of the students. This study provided useful insights into a PBL curriculum at a newly established dental institution. The findings underscore the value of PBL in developing PI and also highlight the challenges of implementing PBL in a socio-cultural context and pedagogical implications for further program improvement.The authors would like to thank all the student participants for their contribution to this research. Open access funding was provided by the Qatar National Library

Effect of dental trauma management resources on dental practitioners' confidence and knowledge: A pilot cross-sectional study

Background/Aim: The knowledge of standardized care guidelines is critical to the confidence of practitioners in managing dental trauma. Therefore, the aim of this study was to assess the awareness, use and impact of the International Association of Dental Traumatology guidelines, and the online Dental Trauma Guide on general dental practitioners' self-reported confidence and knowledge in managing traumatic dental injuries in the primary and permanent dentitions. Materials and Methods: A cross-sectional, pre-piloted, 27-item self-administered questionnaire survey was distributed electronically to general dental practitioners' working within five member states of the Gulf Cooperation Council countries (Kingdom of Bahrain, Kingdom of Saudi Arabia, Kuwait, Oman, and Qatar) between September and December 2020. Data were collected and analysed using descriptive statistics and Wilcoxon Signed Rank test analysis for relevant comparisons. Results: A total of 294 respondents completed the survey, with the majority being from the Kingdom of Saudi Arabia (47.4%) and Qatar (27.3%). A lack of evidence-based knowledge in managing traumatic dental injuries was evident among more than half of the respondents. Respondents who were cognizant of the recent International Association of Dental Traumatology guidelines (2020) and those who use the Dental Trauma Guide routinely demonstrated a higher self-reported confidence level in managing both simple and complex primary dentition trauma, as well as simple traumatic dental injuries in the permanent dentition (p <.05). Conclusion: This survey highlights critical deficiencies in the knowledge of a large number of the respondents in the management of dental trauma which is likely to cause irreversible long-term patient effects.Open Access funding provided by the Qatar National Library

A qualitative enquiry into dental students’ perceptions of dentistry as a career choice in the State of Qatar

Background: Career choice is a complex, multifaceted process affecting all aspects of life. Motivational factors of aspiring dentists are crucial to inform institutions and aid with the admission process. The aim of this study was to explore undergraduate dental students’ perceived motivation for their career choice in the first dental institution in the State of Qatar to bridge the gap in knowledge in this area. Methods: Homogeneous purposive sampling technique was employed to collect data from all year 2 and year 3 undergraduate dental students to gain a deeper insight into their motivation of career choice. An explorative qualitative method using face-to-face focus group sessions were utilized. All focus groups were conducted in English and contained a moderator and observer. A topic guide was used to ensure data collection standardization. Participants’ views were recorded and filed notes obtained. Data was transcribed and analysis performed utilizing an inductive thematic approach. Results: A total of 34 students (89.5%) from year 2 and 3 participated in the focus groups. Data analysis revealed six main themes emerging from this study namely; altruism and patient care, family influence factors, childhood aspirations, hands-on practical skills, professional and social status, and the opportunity to reconsider and transfer. Based on frequency, altruism, opportunities to learn hands-on practical skills and professional status appeared to be the main drivers influencing students’ choice of dentistry as a professional career. Conclusion: This qualitative study presents the first national study providing insightful information regarding current undergraduate dental students’ decision process in relation to their profession selection, and shows that opportunities to provide patient care seems to be the key to motivation. There was also a strong inclination towards performing hands-on practical tasks as a dentist, and developing a professional status. Interestingly, financial reward did not feature as a motivational factor in this study. The study highlights the influence of socio-cultural and economic factors on choosing dentistry as a career. This data could help dental institutions better understand future applicant’s motivations to join dentistry and assist with the academic recruitment/admission process and targeting students with a potential to excel in the profession

Influence of Preclinical Training on Root Canal Treatment Technical Quality and Confidence Level of Undergraduate Dental Students

Objectives. The aim of this study was to investigate the influence of exposure to additional preclinical endodontic training on undergraduate students’ technical quality of root canal treatment and overall confidence levels in endodontics. Methods. Technical quality of root canal treatment performed clinically by fifth-year undergraduate students was evaluated and divided into two groups: Group 1, teeth treated by students who had attended both a preclinical endodontic block course and an elective preclinical course. Group 2: teeth treated by students who had not attended the elective preclinical course. All students were also invited to participate in a survey to rate their undergraduate endodontic training and confidence levels performing endodontic treatment. Statistical analysis of data was performed using Person chi-square test, Fisher Freeman Halton exact test, and t-test. A p-value <0.05 was considered statistically significant. Results. There was no significant difference between the two groups in overall obturation quality (p=0.619). However, more teeth treated by attendees were of adequate obturation length (p=0.015) and lacked procedural errors (p=0.004). Significantly more elective course attendees rated their undergraduate endodontic training as adequate (p=0.002), but there was no significant difference in the level of confidence between the attendees and the non-attendees. Conclusion. Within the limitations of this study, additional preclinical training showed minimal effect on overall quality of root canal treatment performed clinically by undergraduate students and did not enhance their confidence levels; however, it was associated with more satisfaction with their undergraduate endodontic education

Assessment of biomechanical behavior of immature non-vital incisors with various treatment modalities by means of three-dimensional quasi–static finite element analysis

Abstract The objectives of this study were to evaluate the stress distribution and risk of fracture of a non-vital immature maxillary central incisor subjected to various clinical procedures using finite element analysis (FEA). A three-dimensional model of an immature central incisor was developed, from which six main models were designed: untreated immature tooth (C), standard apical plug (AP), resin composite (RC), glass-fibre post (GFP), regeneration procedure (RET), and regeneration with induced root maturation (RRM). Mineral trioxide aggregate (MTA) or Biodentine® were used as an apical or coronal plug. All models simulated masticatory forces in a quasi–static approach with an oblique force of 240 Newton at a 120° to the longitudinal tooth axis. The maximum principal stress, maximum shear stress, risk of fracture, and the strengthening percentage were evaluated. The mean maximum principal stress values were highest in model C [90.3 MPa (SD = 4.4)] and lowest in the GFP models treated with either MTA and Biodentine®; 64.1 (SD = 1.7) and 64.0 (SD = 1.6) MPa, respectively. Regarding the shear stress values, the dentine tooth structure in model C [14.4 MPa (SD = 0.8)] and GFP models [15.4 MPa (SD = 1.1)] reported significantly higher maximum shear stress values compared to other tested models (p  0.05). No significant differences between MTA and Biodentine® regarding maximum principal stress and maximum shear stress values for each tested model (p > 0.05). A maximum strain value of 4.07E−03 and maximum displacement magnitude of 0.128 mm was recorded in model C. In terms of strengthening percentage, the GFP models were associated with the highest increase (22%). The use of a GFP improved the biomechanical performance and resulted in a lower risk of fracture of a non-vital immature maxillary central incisor in a FEA model