Bioactivity and Biocompatibility Properties of Sustainable Wollastonite Bioceramics from Rice Husk Ash/Rice Straw Ash: A Review

Recently, there has been an increase in interest in agricultural waste in scientific, technological, environmental, economic, and social contexts. The processing of rice husk ash/rice straw ash into biocompatible products—also known as biomaterials—used in biomedical implants is a technique that can enhance the value of agricultural waste. This method has effectively converted unprocessed agricultural waste into high-value products. Rice husk and straw are considered to be unwanted agricultural waste and are largely discarded because they pollute the environment. Because of the related components present in bone and teeth, this waste can produce wollastonite. Wollastonite is an excellent material for bone healing and implants, as well as tissue regeneration. The use of rice husk ash or rice straw ash in wollastonite production reduces the impact of agricultural waste on pollution and prompts the ensuing conversion of waste into a highly beneficial invention. The use of this agricultural waste in the fabrication of wollastonite using rice husk ash or rice straw ash was investigated in this paper. Wollastonite made from rice husk ash and rice straw ash has a fair chance of lowering the cost of bone and tooth repair and replacement, while having no environmental effects.

Wnt Signalling in Regenerative Dentistry

Teeth are complex structures where a soft dental pulp tissue is enriched with nerves, vasculature and connective tissue and encased by the cushioning effect of dentin and the protection of a hard enamel in the crown and cementum in the root. Injuries such as trauma or caries can jeopardise these layers of protection and result in pulp exposure, inflammation and infection. Provision of most suitable materials for tooth repair upon injury has been the motivation of dentistry for many decades. Wnt signalling, an evolutionarily conserved pathway, plays key roles during pre- and post-natal development of many organs including the tooth. Mutations in the components of this pathway gives rise to various types of developmental tooth anomalies. Wnt signalling is also fundamental in the response of odontoblasts to injury and repair processes. The complexity of tooth structure has resulted in diverse studies looking at specific compartments or cell types of this organ. This review looks at the current advances in the field of tooth development and regeneration. The objective of the present review is to provide an updated vision on dental biomaterials research, focusing on their biological properties and interactions to act as evidence for their potential use in vital pulp treatment procedures. We discuss the outstanding questions and future directions to make this knowledge more translatable to the clinics.

Self-Assembling Peptide P11-4 Presents Potential of Inducing Odontoblast-Like Cells to Biomineralization and Cell Migration

Self-assembling peptide P11-4 is amphiphilic and pH-triggered with demonstrated effectivity repairing early carious lesions in enamel. However, P11-4 effects on dentin biomineralization and repair remain unexplored. Thus, cytocompatibility and effectiveness of P11-4 inducing mineralization and migration of odontoblast-like cells (MDPC-23) were investigated. MDPC-23 were seeded in contact with P11-4(0.5µg/ml and 1µg/ml), Dentin Matrix Protein 1 (DMP1 0.5µg/ml and 1 µg/ml) or Calcium hydroxide (Ca(OH)2 100µg/ml) solutions. Cytotoxicity was verified using MTT (n=6/group). Mineralization was tested using Alizarin Red (n=4/group). Cell migration was assessed by light microscopy (n=2/group). MTT and Alizarin Red data were compared using Krus-kal-Wallis and Mann-Whitney (α=0.05). P11-4 (0.5µg/ml and 1µg/ml) and DMP1 (0.5µg/ml and 1µg/ml) presented the highest cytocompatibility; Ca(OH)2 presented the lowest. DMP1 1µg/ml exhibited the highest mineralization ability, with no difference to P11-4 1µg/ml. Ca(OH)2 presented lower values than DMP1 1µg/ml (p<0.05), but similar to P11-4 1µg/ml. P11-4 and DMP1 at 0.5 µg/ml showed induced less mineralization than P11-4 and DMP1 at 1µg/ml (p<0.05), with no difference to Ca(OH)2. All materials stimulated cell migration, however, lower concentrations of DMP1 and P11-4 provided better results. P11-4 is cytocompatible, induces mineralization and MDPC-23 migration like DMP1. P11-4 could be an alternative for dentin mineralization and tooth repair.

Biomineralization of Collagen-Based Materials for Hard Tissue Repair

Hydroxyapatite (HA) reinforced collagen fibrils serve as the basic building blocks of natural bone and dentin. Mineralization of collagen fibrils play an essential role in ensuring the structural and mechanical functionalities of hard tissues such as bone and dentin. Biomineralization of collagen can be divided into intrafibrillar and extrafibrillar mineralization in terms of HA distribution relative to collagen fibrils. Intrafibrillar mineralization is termed when HA minerals are incorporated within the gap zone of collagen fibrils, while extrafibrillar mineralization refers to the minerals that are formed on the surface of collagen fibrils. However, the mechanisms resulting in these two types of mineralization still remain debatable. In this review, the evolution of both classical and non-classical biomineralization theories is summarized. Different intrafibrillar mineralization mechanisms, including polymer induced liquid precursor (PILP), capillary action, electrostatic attraction, size exclusion, Gibbs-Donnan equilibrium, and interfacial energy guided theories, are discussed. Exemplary strategies to induce biomimetic intrafibrillar mineralization using non-collagenous proteins (NCPs), polymer analogs, small molecules, and fluidic shear stress are discussed, and recent applications of mineralized collagen fibers for bone regeneration and dentin repair are included. Finally, conclusions are drawn on these proposed mechanisms, and the future trend of collagen-based materials for bone regeneration and tooth repair is speculated.

Tideglusib: The Miracle Molecule for Tooth Repair

Guest Comment by Sahil Gupta titled "Tideglusib: The Miracle Molecule for Tooth Repair"

Oxford Handbook of Clinical Dentistry

The Oxford Handbook of Clinical Dentistry distils the essentials of clinical practice. It balances a pragmatic approach alongside evidence-based clinical knowledge, guidelines, and protocols. It details how to take a history and perform an examination, moving on to discussing preventive and community dentistry, paediatric dentistry, and orthodontics. It thoroughly examines the subject of restorative dentistry through periodontology, tooth repair, tooth replacement, endodontics, and dental implants. It also explores oral surgery, oral medicine, and maxillofacial surgery. It reviews medicine relevant to dentistry, therapeutics, analgesia, anaesthesia, sedation, and dental materials. It explores law and ethics, professionalism and communication, and practice management, as well as syndromes of the head and neck, and also includes summary useful information and addresses. It is written for undergraduate dental students, dental foundation trainees, qualified dental practitioners, medical graduates and nurses involved in hospital dental specialities, and MJDF/MFDS trainees.

Dental stem cells in tooth repair: A systematic review

Background: Dental stem cells (DSCs) are self-renewable teeth cells, which help maintain or develop oral tissues. These cells can differentiate into odontoblasts, adipocytes, cementoblast-like cells, osteoblasts, or chondroblasts and form dentin/pulp. This systematic review aimed to summarize the current evidence regarding the role of these cells in dental pulp regeneration. Methods: We searched the following databases: PubMed, Cochrane Library, MEDLINE, SCOPUS, ScienceDirect, and Web of Science using relevant keywords. Case reports and non-English studies were excluded. We included all studies using dental stem cells in tooth repair whether in vivo or in vitro studies. Results: Dental pulp stem cell (DPSCs) is the most common type of cell. Most stem cells are incorporated and implanted into the root canals in different scaffold forms. Some experiments combine growth factors such as TDM, BMP, and G-CSF with stem cells to improve the results. The transplant of DPSCs and stem cells from apical papilla (SCAPs) was found to be associated with pulp-like recovery, efficient revascularization, enhanced chondrogenesis, and direct vascular supply of regenerated tissue. Conclusion: The current evidence suggests that DPSCs, stem cells from human exfoliated deciduous teeth, and SCAPs are capable of providing sufficient pulp regeneration and vascularization. For the development of the dental repair field, it is important to screen for more effective stem cells, dentine releasing therapies, good biomimicry scaffolds, and good histological markers.