Tooth Repair Research Articles

Evaluation of Silica and Bioglass Nanomaterials in Pulp-like Living Materials.

Although silicon is a widespread constituent in dental materials, its possible influence on the formation and repair of teeth remains largely unexplored. Here, we studied the effect of two silicic acid-releasing nanomaterials, silica and bioglass, on a living model of pulp consisting of dental pulp stem cells seeded in dense type I collagen hydrogels. Silica nanoparticles and released silicic acid had little effect on cell viability and mineralization efficiency but impacted metabolic activity, delayed matrix remodeling, and led to heterogeneous cell distribution. Bioglass improved cell metabolic activity and led to a homogeneous dispersion of cells and mineral deposits within the hydrogel. These results suggest that the presence of calcium ions in bioglass is not only favorable to cell proliferation but can also counterbalance the negative effects of silicon. Both chemical and biological processes should therefore be considered when investigating the effects of silicon-containing materials on dental tissues.

Primary Cilia Regulate the Homeostasis and Regeneration of the Stem Cell Niche in the Tooth.

Primary cilia, functioning as crucial hubs for signal sensing and transduction, are integral to the development and maintenance of homeostasis across various organs. However, their roles in tooth homeostasis and repair remain inadequately understood. In this study, we reveal an indispensable role for primary cilia in regulating the homeostasis and regeneration of teeth, primarily through the regulation of cell proliferation. Using cilium-deficient mice, we demonstrate that disruption of ciliary homeostasis leads to abnormal tooth morphology, stunted growth and notably impaired tooth repair. RNA sequencing reveals a dysregulation in genes associated with various biological processes such as cell proliferation, differentiation, and cycle regulation. Furthermore, we show that cilium-deficient mice display reduced cell proliferation. Our findings highlight a critical function for primary cilia in the regulation of tooth homeostasis and regeneration and have important implications for the development of tooth regeneration therapies.

Periradicular repair after single-visit root canal treatment using sonic irrigant activation of teeth with apical periodontitis.

This study aimed to explore whether using sonic irrigant activation during endodontic treatment favors periradicular repair in teeth with apical periodontitis. One clinician treated 140 posterior (either premolar or molar) asymptomatic teeth with periapical lesions: 70 were randomly assigned to the sonic activation with EndoActivator (EA) group, and 70 were treated by conventional needle irrigation (CNI). Both groups underwent chemomechanical root canal preparation using 35/04 diameter rotary files and 2.5% NaOCl as the irrigant. NaOCl was sonically activated in the EA group, and the final irrigation with NaOCl was performed using a 30-gauge side-perforated needle in the CNI group. All root canal obturations were performed with lateral compaction. All patients were followed up for 12 months. Success was determined based on both healed and healing cases. The chi-square or Fisher's exact test was used to compare success rates and outcome-influencing factors between groups. The recall rate was 131 (94%). At 12 months, 50 teeth (77%) were considered healed, 12 teeth (18%) as healing, and three (5%) as failed in the EA group, while 43 teeth (65%) were considered healed, 17 (26%) as healing, and six (9%) as failed in the CNI group. Verbal Rating Scale scores were significantly lower in the EA group than in the CNI group on postoperative days 1 (p < 0.0001) and 2 (p = 0.0002). Postoperative Periapical Index scores were significantly lower in the EA group than in the CNI group (p = 0.0023). Postoperative lesion sizes were also significantly smaller in the EA group (0.7 [0.2-11.7] mm) than in the CNI group (1.7 [0.5-11.5] mm; p = 0.0118). While the success rate was higher in the EA group (62 [95%]) than in the CNI group (60 [91%]), the difference was not significant (p = 0.492). The periradicular repair of posterior teeth with apical periodontitis demonstrated the efficacy of EndoActivator on treatment outcomes and reduced postoperative pain. These results suggest the adjunctive use of sonic activation to enhance the decontamination of the root canal system during the chemomechanical stage. This clinical trial is the first to evaluate the effects of sonic activation on postoperative healing. Sonic activation with the EndoActivator can reduce postoperative pain and accelerate the healing of the periapical tissues.

Geometry strategies for the repair of cylindrical gears teeth using laser-directed energy deposition

Gears are essential components in power transmission systems. The replacement of the transmission of a wind turbine can reach more than $300 000 and face long lead times. Previous studies have shown that laser-directed energy deposition (L-DED) has the potential to be used in the repair of gears. However, there is a lack of understanding of the appropriate toolpath planning strategies and their impact on the performance of the gears repaired by L-DED. In this work, we study several strategies for the repair of cylindrical (straight and helical) gears. The strategies consider several types of gear tooth failures, allowing for the repair of a portion of the tooth and the reconstruction of the whole tooth. The studied strategies encompass planar and nonplanar slicing procedures. We manufactured several gear teeth to demonstrate the geometrical and kinematic feasibility of some strategies. We performed destructive analyses on the manufactured teeth to check for manufacturing faults. We used AISI 316L for these experiments, although we are assessing and testing powdered materials for their potential use in gear repair using L-DED. Future work will be devoted to the evaluation of the mechanical performance (e.g., wear resistance and bending fatigue) of the teeth manufactured with L-DED.

LESION STERILISATION AND TISSUE REPAIR OF PRIMARY TEETH

BACKGROUND Lesion sterilization and tissue repair is also known as non-instrumental endodontic therapy. It involves the use of combination of antibiotics drugs on infected pulp tissue and root canals after getting access to the root canal orifices of the primary teeth. Various combination of antibiotics had been used by some dentists with macrogol , polyethylene glycol, propylene glycol, normal saline or sterile water as the solvent or vehicle used. METHODS An electronic literature search in Science direct and Google was done in December, 2023 using the Population, Concept and Context framework. Search terms and keywords were combined by Boolean operators. Two independent investigators screened titles and abstracts of publications on lesion sterilization and tissue repair of primary teeth. Original research articles, case report, case series with accessible full text were included for review, while review articles, systematic reviews, viewpoints, books, letters, thesis, editorials, book chapters, dissertations and perspectives were among articles excluded during screening. RESULTS One case report was identified from Morocco, a case series from Nigeria and randomized controlled trial from Egypt respectively. CONCLUSIONS Lesion sterilization and tissue repair or non-instrumental endodontic therapy can be a treatment option for primary teeth with infected pulp and root canals .More studies from diverse ethnic population in Africa countries will fill the gaps in knowledge and add to the existing literature.

Efficient Digital Workflow to Replace a Missing Denture Tooth for Complete Denture Repair.

Debonded denture teeth is a common complication on a fixed or removable dental prosthesis when denture teeth are fabricated separately from the denture base and bonded together. Missing denture teeth can alter a person's appearance, speech, or ability to eat. Traditionally, denture teeth repair can be a challenge for clinicians or dental laboratory technicians to find the identical tooth mould to meet esthetic and functional demands. This case report describes a digital workflow to scan, design, and mill a well-fitting and esthetic denture tooth to expedite treatment, improve patient satisfaction, and increase troop readiness when traditional methods may not be feasible.

The research of collagen for tissue repair in China from 2019 to 2023 based on bibliometrics and visualization analysis

Due to its unique structure, collagen has exceptional biocompatibility, hemostasis, degradability and other biological properties, and is widely used for tissue repair in bone, cartilage, skin, teeth, neurons, cornea, urinary and various other aspects. Therefore, collagen has garnered in significant attention in the field of tissue repair in recent years. Bibliometrics can objectively reflect the hot spots of research and predict the research frontier through quantitative analysis of the quality and quantity of published papers, authors and institutions, and keywords. This paper uses bibliometrics to summarize the number and composition structure of published papers, the quality of published journals, authors/institutions and countries, and keywords in the past five years, aiming to objectively provide an objective overview of the domestic research landscape of collagen for tissue repair research from 2019 to 2023, and hope to offer valuable insights for future related research.

A Successful Reinforcement and Restoration of an Already Damaged Post and Core in a Teeth with an Existing Crown That Has Received Endodontic Treatment: 3 Case Reports

Once correctly indicated, endodontic retreatment requires the preservation of dental components. Effective treatment of teeth with severe damage to the structure of the tooth relies not only on successful endodontic treatment but also on timely postendodontic tooth repair after the same endodontic. Furthermore, for teeth with intracanal posts, the evolution of endodontic procedures and materials has decreased the indication of surgical treatment. Underneath an undamaged crown is a typical clinical occurrence of broken coronal tooth structure. The tooth can be repaired with a post and core if the underlying root is in good condition, and then, the crown is refabricated. This article outlines a method for the aforementioned scenario that makes use of the current unbroken crown. The entire crown was later rescued, and a damaged post and core were also discovered in the canal. The retrieved metallic post was re-cemented in the post space then the undamaged crown was adjusted to fit it, and the opposing arch maintained occlusion. Next, a composite resin that can be dual-cured and built up was poured into the crown, molding it to fit onto the broken tooth. As we know, the core buildup material has a property of dual curing that means it can be self-cured as well as light-cured. Hence, we waited and allowed it to get set by itself chemically. Then, after we carefully removed the crown from over it, a brand-new composite resin core was discovered and adhered to the tooth structure after that we light-cured it for complete the setting process. After that, dual-cured core build-up composite resin was used to re-cement the crown to the core. Even after a year of follow-up, the method of strengthening the tooth’s core and restoring it with the current crown was shown to be effective.

Composite or Modified Hydroxyapatite Microspheres as Drug Delivery Carrier for Bone and Tooth Tissue Engineering.

Since hydroxyapatite (HAp) is an important constituent of bone and teeth, it has excellent biocompatibility and bioactivity, good osteoconductive effects and the ability to induce bone formation as a material for bone or tooth repair and replacement. At present, widely used HAp microspheres have some characteristics, such as large specific surface area, light mass, good injection properties, good fluidity, and low aggregation ability, but they are difficult to really meet the biological and clinical needs due to their own mechanical property defects, such as low strength, brittleness, and poor plasticity. Based on the current research status of HAp microspheres, we summarize the research progress of various types of composite microspheres, including inorganic materials, natural polymer materials and synthetic polymer materials, and further analyze the advantages of HAp composite microspheres loaded with drug molecules, proteins and bioactive factors, so as to explore the development prospect of HAp composite microspheres as scaffolds for constructing sustained release systems. It provides a theoretical basis and research direction to prepare HAp composite micro-spheres with superior comprehensive properties so that they can be better applied in bone tissue regeneration and tooth regeneration engineering.

Ecofriendly and scalable production of bioglass using an organic calcium source enhanced bioactivity for tissue repair

The eco-friendly and scalable production of bioglass remains a challenging but attractive strategy for advancing its widespread biomedical applications. Although the sol–gel method has been considered a valuable approach for bioglass production, the application of calcium nitrate as a calcium source markedly limits its industrialization owing to environmental pollution, high administration costs, and numerous calcium-rich regions in the as-prepared bioglass. Therefore, organic Ca has been proposed as an alternative to inorganic Ca. In the current study, bioglass was successfully prepared using a novel calcium source (calcium glycerol) and was named regeneration silicon (RegeSi). The biocompatibity of bioglass was examined by performing the methyl thiazolyl tetrazolium (MTT) assay using L929 fibroblasts. The biological and tissue repair properties of RegeSi were better than those of bioglass prepared with calcium nitrate using the sol–gel or traditional melting methods. The applicability of RegeSi was validated using suitable wound healing and dental restoration models. Notably, RegeSi ensured closure of a deep wound (1.6 cm diameter, 2 mm depth) within 11 d. Moreover, RegeSi facilitated tooth repair with a blocking rate of 97.1%. More importantly, large-scale production of RegeSi was achieved at low cost, high bioactivity, and using environmental technology, reaching a capacity of 100 kg/batch.

Synthesis of Mesoporous Core Shell Magnetite Bioactive Glass Nanoparticles for Magnetic Hyperthermia Treatment of Cancer

AbstractMultiple biological advances have made use of bioactive glass (BG) nanoparticles (NPs) in regenerative medicine, bone and tooth repair, drug and gene transfer, cancer treatment, and cosmetics. Normal biocompatible coatings alongside hydrocarbons, polymers, and silica significantly affect fundamental attributes of NPs. In this study, we synthesized a novel mesoporous BG NPs with magnetite core shell (AMAG_BG) using L‐arginine as a template processing magnetic hyperthermia (MH). BG network coverage on magnetite (AMAG) NPs were orchestrated first time by bio‐inspired synthesis in watery dissolvable. AMAG and AMAG_BG NPs were characterized by utilizing FE‐SEM, HR‐TEM, and BET analysis. The elemental composition of L‐arginine templated magnetite (AMAG) and AMAG_BG NPs was also determined by XPS and EDX analysis. Characteristics of AMAG_BG were contrasted with bare AMAG NPs in morphology, particle size, porosity, and composition. The fabricated BG NPs′ in‐vitro bioactivity and heat studies were successfully monitored after interaction with simulated bodily fluid (SBF). Magnetic studies and in‐vitro heat studies together demonstrated the behavior of BG NPs towards MH treatment of cancerous cells. Cytotoxicity tests on AMAG_BG NPs using U2OS and human blood cells with appropriate control experiments revealed biocompatibility. The study represents magnetic and thermal property‐dependent sustainable synthetic process of AMAG BG NPs for cancer treatment.

Innovative approaches in regenerative endodontics

Background: Biomimicry or biomimetics refers to developing materials and techniques inspired by natural systems. In dentistry, this approach aims to replicate natural tooth structures and functions, addressing limitations of conventional materials and techniques. Regenerative endodontics, including cell homing and revascularization, represents significant advancements in this field, focusing on pulp-dentin regeneration and tooth vitality restoration. Aim: This review explores innovative biomimetic approaches in regenerative endodontics, including the latest techniques and their clinical implications. It aims to assess the effectiveness and future prospects of these methods in enhancing tooth repair and regeneration. Methods: The review synthesizes current literature on regenerative endodontic procedures, including cell homing, revascularization, scaffold implantation, and gene therapy. It examines experimental studies, clinical trials, and advancements in biomimetic materials and techniques, highlighting their applications and outcomes. Results: The review finds that regenerative endodontics has evolved from traditional apexification to advanced techniques such as cell homing and revascularization. Cell homing, which leverages the body’s natural healing processes without cell transplantation, shows promise in generating pulp-dentin tissue. Revascularization, involving the induction of a blood clot and stem cell recruitment, has demonstrated potential in restoring vitality to necrotic teeth.

Application of a calcium and phosphorus biomineralization strategy in tooth repair: a systematic review.

Biomineralization is a natural process in which organisms regulate the growth of inorganic minerals to form biominerals with unique layered structures, such as bones and teeth, primarily composed of calcium and phosphorus. Tooth decay significantly impacts our daily lives, and the key to tooth regeneration lies in restoring teeth through biomimetic approaches, utilizing mineralization strategies or materials that mimic natural processes. This review delves into the types, properties, and transformations of calcium and phosphorus minerals, followed by an exploration of the mechanisms behind physiological and pathological mineralization in living organisms. It summarizes the mechanisms and commonalities of biomineralization and discusses the advancements in dental biomineralization research, guided by insights into calcium and phosphorus mineral biomineralization. This review concludes by addressing the current challenges and future directions in the field of dental biomimetic mineralization.

Cdc42 deletion yielded enamel defects by disrupting mitochondria and producing reactive oxygen species in dental epithelium

Developmental defects of enamel are common due to genetic and environmental factors before and after birth. Cdc42, a Rho family small GTPase, regulates prenatal tooth development in mice. However, its role in postnatal tooth development, especially enamel formation, remains elusive. Here, we investigated Cdc42 functions in mouse enamel development and tooth repair after birth. Cdc42 showed highly dynamic temporospatial patterns in the developing incisors, with robust expression in ameloblast and odontoblast layers. Strikingly, epithelium-specific Cdc42 deletion resulted in enamel defects in incisors. Ameloblast differentiation was inhibited, and hypomineralization of enamel was observed upon epithelial Cdc42 deletion. Proteomic analysis showed that abnormal mitochondrial components, phosphotransferase activity, and ion channel regulator activity occurred in the Cdc42 mutant dental epithelium. Reactive oxygen species accumulation was detected in the mutant mice, suggesting that abnormal oxidative stress occurred after Cdc42 depletion. Moreover, Cdc42 mutant mice showed delayed tooth repair and generated less calcified enamel. Mitochondrial dysfunction and abnormal oxygen consumption were evidenced by reduced Apool and Timm8a1 expression, increased Atp5j2 levels, and reactive oxygen species overproduction in the mutant repair epithelium. Epithelium-specific Cdc42 deletion attenuated ERK1/2 signaling in the labial cervical loop. Aberrant Sox2 expression in the mutant labial cervical loop after clipping might lead to delayed tooth repair. These findings suggested that mitochondrial dysfunction, up-regulated oxidative stress, and abnormal ion channel activity may be among multiple factors responsible for the observed enamel defects in Cdc42 mutant incisors. Overall, Cdc42 exerts multidimensional and pivotal roles in enamel development and is particularly required for ameloblast differentiation and enamel matrix formation.

Progress in the Application of Biomimetic Mineralization for Tooth Repair

The tooth, including enamel and dentin, is a prominent biomineral that is produced by the biomineralization of living organisms. Although the mechanical performance of the tooth is outstanding, caries easily develop in a complex oral environment. The analysis of the chemical composition and the relationship between the mechanical properties and the structure is of great importance in solving caries. In this review, the multilevel structure and mechanical properties of enamel and dentin are briefly introduced, along with caries formation and the limitations of clinical dental restoration. Furthermore, the progress of the application of a wide range of biomimetic strategies for tooth remineralization is highlighted, including the use of calcium phosphate ionic clusters to construct the mineralization front, ensuring the oriented epitaxial growth of enamel crystals and replicating the complex structure of the enamel. Moreover, compared with the current clinical treatment, in which the resin composite and glass ionomer cement are the main repair materials and the high incidence of secondary caries leads to imperfect restorations, the remineralization tactics could achieve excellent repair effectiveness in reconstructing the complicated structure, restoring mechanical strength and gaining permanent repair. A basic understanding of enamel and dentin, their potential for restoration, and hopeful prospects for tooth repair that can be applied in the clinical setting, not just in the laboratory, is provided by this review.

Guided Tissue Regeneration in Class IV External Cervical Resorption: A Case Report

External cervical resorption (ECR) is a type of dental resorption that originates from the loss of the cementum's protective layer. The direct exposure of dentin to the periodontal ligament may lead to the invasion of clastic cells through an entry point on the external root surface into the dentinal tissue, causing resorption. Depending on the extension of ECR, different treatments are proposed. Although the literature presents distinct materials and methods for restoring ECR areas, an existing gap is related to care in the treatment of the supporting periodontal tissue. Guided tissue regeneration (GTR)/guided bone regeneration includes the stimulation of bone formation in bone defects using different types of membranes (resorbable and nonresorbable), regardless of its association with bone substitutes or grafts. Despite the benefits of guided bone regeneration, the application of this method in cases of ECR is still under-explored in the literature. Thus, the present case report uses GTR with xenogenic material and polydioxanone membrane in a case of class IV ECR. The success of the present case is related to the correct diagnosis and treatment plan. Complete debridement of resorption areas and restoration with biodentine were effective in tooth repair. GTR contributed to the stabilization of supporting periodontal tissues. The association of the xenogeneic bone graft with the polydioxanone membrane proved to be a viable option for restoring the health of the periodontium.

A Review: Impact of Artificial Intelligence on Restorative Dentistry in Recent Times

Artificial intelligence is defined as "the study and improvement of computer systems capable of performing tasks typically requiring cognitive abilities, such as image perception, speech recognition, decision making, and language translation." When a computer imitates analytical traits such as "learning and problem-solving," which humans normally connect with other human brains, the term "AI" is employed. A profusion of studies and papers on the function of AI in restorative dentistry have been published in recent years, with the majority of the efforts focusing on recognising and diagnosing dental disorders such as caries, gum disease, and tooth fractures. The major purpose of this study is to undertake a thorough review of prior research on the impact of artificial intelligence on restorative dentistry. The relevance of the theme tooth reconstruction was prioritised during the search. AI has achieved important improvements in a wide range of medical fields, most notably in dentistry for the diagnosis, localization, classification, estimation, and assessment of dental disease. This review only covers seven papers on the impact of AI on restorative dentistry. Artificial intelligence (AI) has advanced significantly as a powerful tool for computerised tooth repair during the previous two decades. More study is needed, however, to compare different types of AIs and assess their clinical usefulness in occlusal interface restoration.

Organoids from mouse molar and incisor as new tools to study tooth-specific biology and development.

Organoid models provide powerful tools to study tissue biology and development in a dish. Presently, organoids have not yet been developed from mouse tooth. Here, we established tooth organoids (TOs) from early-postnatal mouse molar and incisor, which are long-term expandable, express dental epithelium stem cell (DESC) markers, and recapitulate key properties of the dental epithelium in a tooth-type-specific manner. TOs display invitro differentiation capacity toward ameloblast-resembling cells, even more pronounced in assembloids in which dental mesenchymal (pulp) stem cells are combined with the organoid DESCs. Single-cell transcriptomics supports this developmental potential and reveals co-differentiation into junctional epithelium- and odontoblast-/cementoblast-like cells in the assembloids. Finally, TOs survive and show ameloblast-resembling differentiation also invivo. The developed organoid models provide new tools to study mouse tooth-type-specific biology and development and gain deeper molecular and functional insights that may eventually help to achieve future human biological tooth repair and replacement.

Fabrication of Zirconia Ceramic Dental Crowns by Digital Light Processing: Effects of the Process on Physical Properties and Microstructure.

Highly dense zirconia ceramic dental crowns were successfully fabricated by a digital light processing (DLP) additive manufacturing technique. The effects of slurry solid content and exposure density on printing accuracy, curing depth, shrinkage rate, and relative density were evaluated. For the slurry with a solid content of 80 wt%, the curing depth achieved 40 μm with minimal overgrowth under an exposure intensity of 16.5 mW/cm2. Solid content and sintering temperature had remarkable effects on physical properties and microstructure. Higher solid content resulted in better structural integrity, higher relative density, and denser microstructure. Compressive strength, Vickers hardness, fracture toughness, and wear resistance significantly increase with lifting solid content, reaching values of 677 MPa, 12.62 GPa, 6.3 MPa·m1/2, and 1.5 mg/min, respectively, for 1500°C sintered zirconia dental crowns printed from a slurry with 80 wt% solid content. DLP is deemed a promising technology for the fabrication of zirconia ceramic dental crowns for tooth repair.

Tooth Repair by Treated Dentin Matrix Alone and Impregnated with Bone Marrow Mesenchymal Stem Cells in Rabbits

Tooth Repair by Treated Dentin Matrix Alone and Impregnated with Bone Marrow Mesenchymal Stem Cells in Rabbits