[The efficacy of iRoot BP plus in the treatment of adult carious pulp exposure and its impact on pulp blood flow].

PURPOSE: To explore the efficacy of iRoot BP plus in the treatment of adult carious pulp exposure and its impact on pulp blood flow. METHODS: A total of 126 cases of 156 permanent teeth from adult patients with carious pulp exposure who were treated from January 2020 to January 2022 were selected, the patients were divided into experimental group(63 cases with 79 permanent teeth) and control group(63 cases with 77 permanent teeth) by the envelope method. The experimental group was treated with iRoot BP plus, while the control group was treated with mineral trioxide polymer. The differences in treatment effectiveness, operation time, and tooth discoloration between the two groups were observed. Statistical analysis was performed with SPSS 22.0 software package. RESULTS: There was no significant difference in treatment success rates between the experimental group and the control group at 3, 6, and 12 months after surgery(P＞0.05). The operating time for each capsule in the experimental group was (2.53±0.41) min, which was significantly shorter than that in the control group(P＜0.05). The incidence of tooth discoloration in the experimental group at 12 months after surgery was 3.80%, which was significantly lower than that in the control group (P＜0.05). The bite force quotient and masticatory efficiency of the experimental group 12 months after operation were (16.65±1.14) Ibs and (94.45±5.65)%, which were significantly higher than those of the control group(P＜0.05). CONCLUSIONS: IRoot BP plus has good efficacy in the treatment of adult carious pulp exposure, with advantages such as convenient operation, less tooth discoloration, less inflammatory reactions and stable pulp blood flow after decline.

Apoptotic Extracellular Vesicles from Supernumerary Tooth-Derived Pulp Stem Cells Transfer COL1A1 to Promote Angiogenesis via PI3K/Akt/VEGF Pathway.

Purpose: Angiogenesis is a tightly controlled process that initiates the formation of new vessels and its dysfunction can lead to life-threatening diseases. Apoptotic extracellular vesicles (ApoEVs) have emerged as a proangiogenic agent with high safety and isolation efficiency profile, and ApoEVs from supernumerary tooth-derived pulp stem cells (SNTSC-ApoEVs) have their unique advantages with an easily accessible parental cell source and non-invasive cell harvesting. However, the detailed characteristics of SNTSC-ApoEVs are largely unknown. This study aimed to investigate the proangiogenic capacity and function molecule of SNTSC-ApoEVs. Methods: SNTSC-ApoEVs were isolated and characterized. In vitro effects of SNTSC-ApoEVs on the proliferation, migration, and tube formation of human umbilical vein endothelial cells (HUVECs) were evaluated by CCK-8, wound healing, transwell, and tube formation assays. The mRNA and protein levels of proangiogenic genes were quantified by qRT-PCR, Western blot, and immunofluorescence analysis. A Matrigel plug model was established in 6-week-old male nu/nu mice for one week, and the in vivo impact of SNTSC-ApoEVs on micro-vessel formation was assessed by histological analysis. Proteomic analysis and RNA sequencing were performed to explore the active ingredients and underlying mechanisms. Results: SNTSC-ApoEVs enhanced the proliferation, migration, and angiogenesis of HUVECs in vitro. In the Matrigel plug model in vivo, SNTSC-ApoEVs promoted CD31-positive luminal structure formation. Apart from expressing general ApoEV markers, SNTSC-ApoEVs were enriched with multiple proteins related to extracellular matrix-cell interactions. Mechanistically, SNTSC-ApoEVs transferred COL1A1 to HUVECs and promoted endothelial functions by activating the PI3K/Akt/VEGF cascade. Conclusion: SNTSC-ApoEVs can promote angiogenesis by transferring the functional molecule COL1A1 and activating the PI3K/Akt/VEGF pathway, making SNTSC-ApoEVs a promising strategy for the treatment of angiogenesis-related diseases.

Impaired Tertiary Dentin Secretion after Shallow Injury in Tgfbr2-Deficient Dental Pulp Cells Is Rescued by Extended CGRP Signaling.

The transforming growth factor ß (TGFß) superfamily is a master regulator of development, adult homeostasis, and wound repair. Dysregulated TGFß signaling can lead to cancer, fibrosis, and musculoskeletal malformations. We previously demonstrated that TGFß receptor 2 (Tgfbr2) signaling regulates odontoblast differentiation, dentin mineralization, root elongation, and sensory innervation during tooth development. Sensory innervation also modulates the homeostasis and repair response in adult teeth. We hypothesized that Tgfbr2 regulates the neuro-pulpal responses to dentin injury. To test this, we performed a shallow dentin injury with a timed deletion of Tgfbr2 in the dental pulp mesenchyme of mice and analyzed the levels of tertiary dentin and calcitonin gene-related peptide (CGRP) axon sprouting. Microcomputed tomography imaging and histology indicated lower dentin volume in Tgfbr2cko M1s compared to WT M1s 21 days post-injury, but the volume was comparable by day 56. Immunofluorescent imaging of peptidergic afferents demonstrated that the duration of axon sprouting was longer in injured Tgfbr2cko compared to WT M1s. Thus, CGRP+ sensory afferents may provide Tgfbr2-deficient odontoblasts with compensatory signals for healing. Harnessing these neuro-pulpal signals has the potential to guide the development of treatments for enhanced dental healing and to help patients with TGFß-related diseases.

Enhancing Dental Pulp Stem Cell Proliferation and Odontogenic Differentiation with Protein Phosphatase 1-Disrupting Peptide: An In Vitro Study.

The reparative and regenerative capabilities of dental pulp stem cells (DPSCs) are crucial for responding to pulp injuries, with protein phosphatase 1 (PP1) playing a significant role in regulating cellular functions pertinent to tissue healing. Accordingly, this study aimed to explore the effects of a novel cell-penetrating peptide Modified Sperm Stop 1-MSS1, that disrupts PP1, on the proliferation and odontogenic differentiation of DPSCs. Employing MSS1 as a bioportide, DPSCs were cultured and characterized for metabolic activity, cell proliferation, and cell morphology alongside the odontogenic differentiation through gene expression and alkaline phosphatase (ALP) activity analysis. MSS1 exposure induced early DPSC proliferation, upregulated genes related to odontogenic differentiation, and increased ALP activity. Markers associated with early differentiation events were induced at early culture time points and those associated with matrix mineralization were upregulated at mid-culture stages. This investigation is the first to document the potential of a PP1-disrupting bioportide in modulating DPSC functionality, suggesting a promising avenue for enhancing dental tissue regeneration and repair.

Advances in Regenerative Dentistry: A Systematic Review of Harnessing Wnt/ß-Catenin in Dentin-Pulp Regeneration.

Dentin pulp has a complex function as a major unit in maintaining the vitality of teeth. In this sense, the Wnt/ß-Catenin pathway has a vital part in tooth development, maintenance, repair, and regeneration by controlling physiological activities such as growth, differentiation, and migration. This pathway consists of a network of proteins, such as Wnt signaling molecules, which interact with receptors of targeted cells and play a role in development and adult tissue homeostasis. The Wnt signals are specific spatiotemporally, suggesting its intricate mechanism in development, regulation, repair, and regeneration by the formation of tertiary dentin. This review provides an overview of the recent advances in the Wnt/ß-Catenin signaling pathway in dentin and pulp regeneration, how different proteins, molecules, and ligands influence this pathway, either upregulating or silencing it, and how it may be used in the future for clinical dentistry, in vital pulp therapy as an effective treatment for dental caries, as an alternative approach for root canal therapy, and to provide a path for therapeutic and regenerative dentistry.

Preservation of Pulp Vitality in Type IIIA Dens Invaginatus with an Extensive Peri-invagination Lesion: a case Report with 5-year Follow-up.

Dens invaginatus may be associated with peri-invagination lesions and vital pulp concurrently. This case report examines the successful preservation of vital pulp and minimally invasive treatment of invagination for Oehlers type IIIA dens invaginatus with an extensive peri-invagination lesion. A healthy 19-year-old man presented with occasional swelling of the left maxillary anterior region. Pulp vitality tests revealed vital and healthy tooth pulp. CBCT indicated Oehlers type IIIA dens invaginatus with an invagination parallel to the pulp cavity. The diagnosis was type IIIA dens invaginatus with a peri-invagination lesion. The treatment plans involved preservation of the vital pulp and minimally invasive treatment of the invagination. A 5-year follow-up revealed that both healing of the peri-invagination lesion and preservation of the vital pulp had been successful. Pulp vitality can be preserved in type IIIA dens invaginatus associated with a peri-invagination lesion through minimally invasive treatment of the invagination.

Novel L-(CaP-ZnP)/SA Nanocomposite Hydrogel with Dual Anti-Inflammatory and Mineralization Effects for Efficient Vital Pulp Therapy.

Background: Vital pulp therapy (VPT) is considered a conservative treatment for preserving pulp viability in caries and trauma-induced pulpitis. However, Mineral trioxide aggregate (MTA) as the most frequently used repair material, exhibits limited efficacy under inflammatory conditions. This study introduces an innovative nanocomposite hydrogel, tailored to simultaneously target anti-inflammation and dentin mineralization, aiming to efficiently preserve vital pulp tissue. Methods: The L-(CaP-ZnP)/SA nanocomposite hydrogel was designed by combining L-Arginine modified calcium phosphate/zinc phosphate nanoparticles (L-(CaP-ZnP) NPs) with sodium alginate (SA), and was characterized with TEM, SEM, FTIR, EDX, ICP-AES, and Zeta potential. In vitro, we evaluated the cytotoxicity and anti-inflammatory properties. Human dental pulp stem cells (hDPSCs) were cultured with lipopolysaccharide (LPS) to induce an inflammatory response, and the cell odontogenic differentiation was measured and possible signaling pathways were explored by alkaline phosphatase (ALP)/alizarin red S (ARS) staining, qRT-PCR, immunofluorescence staining, and Western blotting, respectively. In vivo, a pulpitis model was utilized to explore the potential of the L-(CaP-ZnP)/SA nanocomposite hydrogel in controlling pulp inflammation and enhancing dentin mineralization by Hematoxylin and eosin (HE) staining and immunohistochemistry staining. Results: In vitro experiments revealed that the nanocomposite hydrogel was synthesized successfully and presented desirable biocompatibility. Under inflammatory conditions, compared to MTA, the L-(CaP-ZnP)/SA nanocomposite hydrogel demonstrated superior anti-inflammatory and pro-odontogenesis effects. Furthermore, the nanocomposite hydrogel significantly augmented p38 phosphorylation, implicating the involvement of the p38 signaling pathway in pulp repair. Significantly, in a rat pulpitis model, the L-(CaP-ZnP)/SA nanocomposite hydrogel downregulated inflammatory markers while upregulating mineralization-related markers, thereby stimulating the formation of robust reparative dentin. Conclusion: The L-(CaP-ZnP)/SA nanocomposite hydrogel with good biocompatibility efficiently promoted inflammation resolution and enhanced dentin mineralization by activating p38 signal pathway, as a pulp-capping material, offering a promising and advanced solution for treatment of pulpitis.

Complete versus incomplete caries removal procedures and their effects on dental pulp in primary teeth - An in vivo study.

INTRODUCTION: Dental caries results from an ecologic shift within the dental biofilm from a balanced population of microorganisms to an acidogenic, aciduric, and cariogenic microbiological population developed and maintained by frequent consumption of fermentable dietary carbohydrates. Total caries removal (TCR) of deep lesion may result in pulpal exposure requiring more invasive treatment. Hence, current pediatric dentistry has shifted to minimally invasive treatment that avoids more complex, time-consuming procedure, and the child's discomfort. AIM: The aim of this study is to evaluate and compare clinical performance and radiographic changes after complete and incomplete caries removal procedures. MATERIALS AND METHODS: The study was conducted on 60 primary molars in children aged 6-9 years. Selected 60 primary molars were randomly divided into two groups. Group 1 (PCR): infected dentin was removed, while the affected dentin was maintained on the pulpal wall. Group 2 (TCR): both infected and affected dentin were removed through low-speed carbide bur and hand excavator. Teeth were evaluated at 4 and 6 months clinically and radiographically. RESULTS: The proportion was compared using Fisher's exact test. The Statistical Package for the Social Sciences version 21 was used for analysis. The level of significance was kept at 5%. CONCLUSION: The clinical and radiographic success rates of ICR and CCR in primary teeth with deep carious lesions were high and did not differ significantly, indicating that the retention of carious dentin does not interfere with pulp vitality. Thus, ICR is a reliable minimally invasive approach that might replace the CCR in primary teeth when correctly indicated.

A new subtype of artificial cell-derived vesicles from dental pulp stem cells with the bioequivalence and higher acquisition efficiency compared to extracellular vesicles.

Extracellular vesicles (EVs) derived from dental pulp stem cells (DPSC) have been shown an excellent efficacy in a variety of disease models. However, current production methods fail to meet the needs of clinical treatment. In this study, we present an innovative approach to substantially enhance the production of 'Artificial Cell-Derived Vesicles (ACDVs)' by extracting and purifying the contents released by the DPSC lysate, namely intracellular vesicles. Comparative analysis was performed between ACDVs and those obtained through ultracentrifugation. The ACDVs extracted from the cell lysate meet the general standard of EVs and have similar protein secretion profile. The new ACDVs also significantly promoted wound healing, increased or decreased collagen regeneration, and reduced the production of inflammatory factors as the EVs. More importantly, the extraction efficiency is improved by 16 times compared with the EVs extracted using ultracentrifuge method. With its impressive attributes, this new subtype of ACDVs emerge as a prospective candidate for the future clinical applications in regenerative medicine.

Regenerative Potential of Dental Pulp Stem Cells in Response to a Bioceramic Dental Sealer and Photobiomodulation: An In Vitro Study.

AIMS: This study aims to assess the synergistic effect of utilizing a bioceramic sealer, NeoPutty, with photobiomodulation (PBM) on dental pulp stem cells (DPSCs) for odontogenesis. MATERIALS AND METHODS: Dental pulp stem cells were collected from 10 premolars extracted from healthy individuals. Dental pulp stem cells were characterized using an inverted-phase microscope to detect cell shape and flow cytometry to detect stem cell-specific surface antigens. Three experimental groups were examined: the NP group, the PBM group, and the combined NP and PBM group. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) experiment was conducted to assess the viability of DPSCs. The odontogenic differentiation potential was analyzed using Alizarin red staining, RT-qPCR analysis of odontogenic genes DMP-1, DSPP, and alkaline phosphatase (ALP), and western blot analysis for detecting BMP-2 and RUNX-2 protein expression. An analysis of variance (ANOVA) followed by a post hoc t-test was employed to examine and compare the mean values of the results. RESULTS: The study showed a notable rise in cell viability when NP and PBM were used together. Odontogenic gene expression and the protein expression of BMP-2 and RUNX-2 were notably increased in the combined group. The combined effect of NeoPutty and PBM was significant in enhancing the odontogenic differentiation capability of DPSCs. CONCLUSION: The synergistic effect of NeoPutty and PBM produced the most positive effect on the cytocompatibility and odontogenic differentiation potential of DPSCs. CLINICAL SIGNIFICANCE: Creating innovative regenerative treatments to efficiently and durably repair injured dental tissues. How to cite this article: Alshawkani HA, Mansy M, Al Ankily M, et al. Regenerative Potential of Dental Pulp Stem Cells in Response to a Bioceramic Dental Sealer and Photobiomodulation: An In Vitro Study. J Contemp Dent Pract 2024;25(4):313-319.

Heparin-Functionalized Bioactive Glass to Harvest Endogenous Growth Factors for Pulp Regeneration.

Pulp and periapical diseases can lead to the cessation of tooth development, resulting in compromised tooth structure and functions. Despite numerous efforts to induce pulp regeneration, effective strategies are still lacking. Growth factors (GFs) hold considerable promise in pulp regeneration due to their diverse cellular regulatory properties. However, the limited half-lives and susceptibility to degradation of exogenous GFs necessitate the administration of supra-physiological doses, leading to undesirable side effects. In this research, a heparin-functionalized bioactive glass (CaO-P2O5-SiO2-Heparin, abbreviated as PSC-Heparin) with strong bioactivity and a stable neutral pH is developed as a promising candidate to addressing challenges in pulp regeneration. Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis reveal the successful synthesis of PSC-Heparin. Scanning electron microscopy and X-ray diffraction show the hydroxyapatite formation can be observed on the surface of PSC-Heparin after soaking in simulated body fluid for 12 h. PSC-Heparin is capable of harvesting various endogenous GFs and sustainably releasing them over an extended duration by the enzyme-linked immunosorbent assay. Cytological experiments show that developed PSC-Heparin can facilitate the adhesion, migration, proliferation, and odontogenic differentiation of stem cells from apical papillae. Notably, the histological analysis of subcutaneous implantation in nude mice demonstrates PSC-Heparin is capable of promoting the odontoblast-like layers and pulp-dentin complex formation without the addition of exogenous GFs, which is vital for clinical applications. This work highlights an effective strategy of harvesting endogenous GFs and avoiding the involvement of exogenous GFs to achieve pulp-dentin complex regeneration, which may open a new horizon for regenerative endodontic therapy.

Cartilage-Specific Gene Expression and Extracellular Matrix Deposition in the Course of Mesenchymal Stromal Cell Chondrogenic Differentiation in 3D Spheroid Culture.

Articular cartilage damage still remains a major problem in orthopedical surgery. The development of tissue engineering techniques such as autologous chondrocyte implantation is a promising way to improve clinical outcomes. On the other hand, the clinical application of autologous chondrocytes has considerable limitations. Mesenchymal stromal cells (MSCs) from various tissues have been shown to possess chondrogenic differentiation potential, although to different degrees. In the present study, we assessed the alterations in chondrogenesis-related gene transcription rates and extracellular matrix deposition levels before and after the chondrogenic differentiation of MSCs in a 3D spheroid culture. MSCs were obtained from three different tissues: umbilical cord Wharton's jelly (WJMSC-Wharton's jelly mesenchymal stromal cells), adipose tissue (ATMSC-adipose tissue mesenchymal stromal cells), and the dental pulp of deciduous teeth (SHEDs-stem cells from human exfoliated deciduous teeth). Monolayer MSC cultures served as baseline controls. Newly formed 3D spheroids composed of MSCs previously grown in 2D cultures were precultured for 2 days in growth medium, and then, chondrogenic differentiation was induced by maintaining them in the TGF-ß1-containing medium for 21 days. Among the MSC types studied, WJMSCs showed the most similarities with primary chondrocytes in terms of the upregulation of cartilage-specific gene expression. Interestingly, such upregulation occurred to some extent in all 3D spheroids, even prior to the addition of TGF-ß1. These results confirm that the potential of Wharton's jelly is on par with adipose tissue as a valuable cell source for cartilage engineering applications as well as for the treatment of osteoarthritis. The 3D spheroid environment on its own acts as a trigger for the chondrogenic differentiation of MSCs.

Overexpression of programmed cell death ligand 1 reduces LPS-induced inflammatory cytokine upregulation and enhances osteo/odontogenic-differentiation of human dental pulp stem cells via upregulation of CCCTC-binding factor.

OBJECTIVE: The aim of this study was to explore the effect and mechanism of programmed cell death ligand 1 (PD-L1) in promoting the proliferation and osteo/odontogenic-differentiation of human dental pulp stem cells (hDPSCs) by mediating CCCTC-binding factor (CTCF) expression. DESIGN: The interaction between PD-L1 and CTCF was verified through co-immunoprecipitation. hDPSCs transfected with PD-L1 overexpression and CTCF knockdown vectors were treated with lipopolysaccharide or an osteogenic-inducing medium. Inflammatory cytokines and osteo/odontogenic-differentiation related genes were measured. Osteo/odontogenic-differentiation of hDPSCs was assessed using alkaline phosphatase (ALP) and alizarin red S staining. RESULTS: Overexpression of PD-L1 inhibited LPS-induced pro-inflammatory cytokine upregulation, cell proliferation, ALP activity, and calcium deposition in hDPSCs and elevated the expression of osteo/odontogenic-differentiation related genes; however, such expression patterns could be reversed by CTCF knockdown. Co-immunoprecipitation results confirmed the binding of PD-L1 to CTCF, indicating that PD-L1 overexpression in hDPSCs increases CTCF expression, thus inhibiting the inflammatory response and increasing osteo/odontogenic-differentiation of hDPSCs. CONCLUSION: PD-L1 overexpression in hDPSCs enhances the proliferation and osteo/odontogenic-differentiation of hDPSCs and inhibit the inflammatory response by upregulating CTCF expression.

Intracranial graft of bioresorbable polymer scaffolds loaded with human Dental Pulp Stem Cells in stab wound murine injury model.

The prevalence of central nervous system (CNS) dysfunction as a result of disease or trauma remains a clinically unsolved problem which is raising increased awareness in our aging society. Human Dental Pulp Stem Cells (hDPSCs) are excellent candidates to be used in tissue engineering and regenerative therapies of the CNS due to their neural differentiation ability and lack of tumorigenicity. Accordingly, they have been successfully used in animal models of spinal cord injury, stroke and peripheral neuropathies. The ideal therapy in brain injury should combine strategies aiming to protect the damaged lesion and, at the same time, accelerate brain tissue regeneration, thus promoting fast recovery while minimizing side or long-term effects. The use of bioresorbable nanopatterned poly(lactide-co-ɛ-caprolactone) (PLCL) polymeric scaffolds as hDPCSs carriers can represent an advantage for tissue regeneration. In this chapter, we describe the surgical procedures to implant functionalized bioresorbable scaffolds loaded with hDPSCs to improve the brain lesion microenvironment in an intracranial stab wound injury model severing the rostral migratory stream (RMS) that connects the brain subventricular zone (SVZ) and the olfactory bulb in nude mice. Additionally, we also describe the technical steps after animal sacrifice for histological tissue observation and characterization.

Assessing the efficacy of various irrigation solutions in dissolving organic tissue.

For successful root canal treatment, adequate chemomechanical instrumentation to eliminate microorganisms and pulp tissue is crucial. This study aims to assess the organic tissue dissolving activity of various irrigation solutions on bovine tooth pulp tissue. 40 extracted bovine mandibular anterior teeth (n = 10) were used for the study. Bovine pulp pieces (25 ± 5 mg) were placed in 1.5 ml Eppendorf tubes. Each tooth pulp sample was then covered with 1.5 ml of different irrigation solutions, dividing them into four groups: Group 1 with freshly prepared 5% Boric acid, Group 2 with 5% NaOCl, Group 3 with Irritrol, and Group 4 with Saline. Samples were left at room temperature for 30 min, then dried and reweighed. The efficacy of tissue dissolution ranked from highest to lowest was found to be NaOCl, Boric Acid, Irritrol, and saline (p < 0.05). It was observed that the decrease in the NaOCl group was greater than the decrease in the Irritrol and saline groups, and the decrease in the Boric acid group was significantly greater than the decrease in the saline group (p < 0.05). It also emphasizes the need for future studies to further investigate the effects of Irritrol and Boric Acid on tissue dissolution.

Platelet-rich fibrin (PRF) modified nano-hydroxyapatite/chitosan/gelatin/alginate scaffolds increase adhesion and viability of human dental pulp stem cells (DPSC) and osteoblasts derived from DPSC.

Bone tissue regeneration strategies have incorporated the use of natural polymers, such as hydroxyapatite (nHA), chitosan (CH), gelatin (GEL), or alginate (ALG). Additionally, platelet concentrates, such as platelet-rich fibrin (PRF) have been suggested to improve scaffold biocompatibility. This study aimed to develop scaffolds composed of nHA, GEL, and CH, with or without ALG and lyophilized PRF, to evaluate the scaffold's properties, growth factor release, and dental pulp stem cells (DPSC), and osteoblast (OB) derived from DPSC viability. Four scaffold variations were synthesized and lyophilized. Then, degradation, swelling profiles, and morphological analysis were performed. Furthermore, PDGF-BB and FGF-B growth factors release were quantified by ELISA, and cytotoxicity and cell viability were evaluated. The swelling and degradation profiles were similar in all scaffolds, with pore sizes ranging between 100 and 250 µm. FGF-B and PDGF-BB release was evidenced after 24 h of scaffold immersion in cell culture medium. DPSC and OB-DPSC viability was notably increased in PRF-supplemented scaffolds. The nHA-CH-GEL-PRF scaffold demonstrated optimal physical-biological characteristics for stimulating DPSC and OB-DPSC cell viability. These results suggest lyophilized PRF improves scaffold biocompatibility for bone tissue regeneration purposes.

Adolescents and Children Age Estimation Using Machine Learning Based on Pulp and Tooth Volumes on CBCT Images.

OBJECTIVES: To estimate adolescents and children age using stepwise regression and machine learning methods based on the pulp and tooth volumes of the left maxillary central incisor and cuspid on cone beam computed tomography (CBCT) images, and to compare and analyze the estimation results. METHODS: A total of 498 Shanghai Han adolescents and children CBCT images of the oral and maxillofacial regions were collected. The pulp and tooth volumes of the left maxillary central incisor and cuspid were measured and calculated. Three machine learning algorithms (K-nearest neighbor, ridge regression, and decision tree) and stepwise regression were used to establish four age estimation models. The coefficient of determination, mean error, root mean square error, mean square error and mean absolute error were computed and compared. A correlation heatmap was drawn to visualize and the monotonic relationship between parameters was visually analyzed. RESULTS: The K-nearest neighbor model (R2=0.779) and the ridge regression model (R2=0.729) outperformed stepwise regression (R2=0.617), while the decision tree model (R2=0.494) showed poor fitting. The correlation heatmap demonstrated a monotonically negative correlation between age and the parameters including pulp volume, the ratio of pulp volume to hard tissue volume, and the ratio of pulp volume to tooth volume. CONCLUSIONS: Pulp volume and pulp volume proportion are closely related to age. The application of CBCT-based machine learning methods can provide more accurate age estimation results, which lays a foundation for further CBCT-based deep learning dental age estimation research.

Determining Whether an Individual is 18 Years or Older Based on the Third Molar Root Pulp Visibility in East China.

OBJECTIVES: To investigate the age-related changes of the mandibular third molar root pulp visibility in individuals in East China, and to explore the feasibility of applying this method to determine whether an individual is 18 years or older. METHODS: A total of 1 280 oral panoramic images were collected from the 15-30 years old East China population, and the mandibular third molar root pulp visibility in all oral panoramic images was evaluated using OLZE 0-3 four-stage method, and the age distribution of the samples at each stage was analyzed using descriptive statistics. RESULTS: Stages 0, 1, 2 and 3 first appeared in 16.88, 19.18, 21.91 and 25.44 years for males and in 17.47, 20.91, 22.01 and 26.01 years for females. In all samples, individuals at stages 1 to 3 were over 18 years old. CONCLUSIONS: It is feasible to determine whether an individual in East China is 18 years or older based on the mandibular third molar root pulp visibility on oral panoramic images.

Comparative cell viability of dentin-bonding adhesive systems on human dental pulp stem cells: time-dependent analysis.

BACKGROUND: Restorative materials are in prolonged contact with living tissues such as oral mucosa, dentin, pulp, periodontal, and periapical tissues. Therefore, the potentially harmful effects of these materials and their components on oral tissues should be evaluated before clinical use. This study aimed to compare the cell viability of different adhesive systems (ASs) on human dental pulp stem cells (hDPSCs). METHODS: Three ASs that combining methacryloyloxydecyl dihydrogen phosphate (MDP) monomer with new hydrophilic amide monomers [Clearfil Universal Bond Quick(CUBQ), Kuraray Noritake], self-reinforcing 3D monomer [Bond Force II(BFII), Tokuyama)], and dual-cure property [Futurabond DC(FBDC), VOCO] were used. Three (n = 3) samples were prepared for each group. Dental pulp stem cells were isolated from ten patients' extracted third molar teeth. Samples were incubated in Dulbecco's modified Eagle's medium (DMEM) for 24 h (h), 72 h, and 7 days (d) to obtain extracts. For the control group, cells were cultured without DBA samples. Cell viability of ASs extracts was measured using a cell proliferation detection kit (WST-1, Roche). Statistical analysis was performed using two-way ANOVA and post-hoc (Duncan) tests (p < 0.05). RESULTS: At 24 and 72 h statistically significant differences were determined between control and BFII, control and FBDC groups (p < 0.05), while no differences between control and CUBQ groups (p > 0.05). On the 7th d, statistically significant differences were found between the control and experimental groups (p < 0.05), while no differences between experimental groups (p > 0.05). A statistically significant difference was detected for the BFII group over the three-time interval (p < 0.05). The lowest cell viability was observed for the FBDC group at 24 h, and the difference was statistically significant when compared with 72 h and 7th d (p < 0.05). CONCLUSION: All ASs showed different cell viability values at various exposure times. It should be taken into consideration that pH values, as well as the contents of ASs, have a significant effect on the cell viability.