Biomolecules and material-tissue interactions in regenerative dentistry

Periodontal disease is a prevalent condition affecting a substantial proportion of the global population. It has a significant impact on the quality of life and its incidence is projected to increase as the population ages. This habilitation work focuses on various aspects of periodontal regeneration, personalized periodontics, and the influence of materials and interventions on periodontal and peri-implant health. The first part of the research explores the role of biomolecules in periodontal regeneration and repair. While common periodontal treatments result in tissue repair, the ultimate objective is achieving complete regeneration. Regenerative procedures that aim to restore lost or injured tissues in periodontal disease are being extensively studied. Two specific biomolecules, amelogenin (component of EMD) and hyaluronic acid (HA), were examined for promoting the regeneration of periodontal tissues. The studies evaluated the effects of these biomolecules on cell proliferation, migration, and differentiation, highlighting their potential in improving periodontal tissue regeneration. One study specifically focused on a recombinant version of the main protein found in EMD, amelogenin, investigating the effects of the full-length protein on periodontal wound healing and its interaction with oral keratinocytes. The results show that amelogenin inhibits the motility and proliferation of keratinocytes, suggesting its potential in preventing the occupation of periodontal ligament space by these cells. Another study explored the influence of different molecular weights of hyaluronic acid on periodontal ligament cells. Hyaluronic acid fragments induce osteogenic differentiation in these cells, with medium molecular weight hyaluronic acid showing the most significant effects. The study highlights the importance of considering the molecular weight of hyaluronic acid in its clinical application for periodontal therapy. The second part of the research focuses on the use of biomolecules in the diagnosis, monitoring, and treatment of periodontal conditions. It discusses the potential of cytokines, such as interleukin-8 (IL-8), as diagnostic markers for periodontitis. The study showed a strong correlation between IL-8 levels in gingival crevicular fluid and the clinical severity of periodontitis. The research also investigated the correlation between IL-8 levels and smoking habits, revealing that for this group IL-8 cannot serve as a biomarker of periodontitis. Additionally, the research explored the effects of prostaglandins E2 (PGE2) and D2 (PGD2) on cell proliferation and osteogenic capacity of human mesenchymal stem cells. It demonstrated that both PGE2 and PGD2 negatively affect osteogenic differentiation and metabolism, suggesting their involvement in periodontitis-induced tissue damage. The third part of the research examines the influence of materials and iatrogenic interventions on periodontal and peri-implant health. One study investigated the ultrastructural changes of titanium implant surfaces caused by metal and plastic periodontal probes. Although slight changes in surface roughness were observed, they did not reach statistical significance. Further studies need to investigate how routine probing might affect the reattachment of osteoblasts after peri-implant defect treatment. Two other studies focused on the cytotoxicity of 3D printed resin materials used for temporary dental restorations. The research evaluated the effects of these materials on human periodontal ligament cells and gingival keratinocytes. The results indicate a higher cytotoxicity of 3D printed resin materials compared to conventional and subtractive manufacturing materials. Overall, this research provides valuable insights into the biological principles of regenerative materials, the potential of biomolecules in periodontal therapy, the use of molecules as diagnostic markers, and the influence of materials and interventions on periodontal and peri-implant health. The findings contribute to the advancement of periodontal treatment and personalized dentistry, aiming to improve patient care and outcomes in the field of periodontology

The state of additive manufacturing in dental research – A systematic scoping review of 2012–2022

Background/purpose: Additive manufacturing (AM), also known as 3D printing, has the potential to transform the industry. While there have been advancements in using AM for dental restorations, there is still a need for further research to develop functional biomedical and dental materials. It’s crucial to understand the current status of AM technology and research trends to advance dental research in this field. The aim of this study is to reveal the current status of international scientific publications in the field of dental research related to AM technologies. Materials and methods: In this study, a systematic scoping review was conducted using appropriate keywords within the scope of international scientific publishing databases (PubMed and Web of Science). The review included related clinical and laboratory research, including both human and animal studies, case reports, review articles, and questionnaire studies. A total of 187 research studies were evaluated for quantitative synthesis in this review. Results: The findings highlighted a rising trend in research numbers over the years (From 2012 to 2022). The most publications were produced in 2020 and 2021, with annual percentage increases of 25.7% and 26.2%, respectively. The majority of AM-related publications in dentistry research originate from Korea. The pioneer dental sub-fields with the ost publications in its category are prosthodontics and implantology, respectively. Conclusion: The final review result clearly stated an expectation for the future that the research in dentistry would concentrate on AM technologies in order to increase the new product and process development in dental materials, tools, implants and new generation modelling strategy related to AM. The results of this work can be used as indicators of trends related to AM research in dentistry and/or as prospects for future publication expectations in this field