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16 pages, 4302 KiB

Open AccessArticle

Transcriptional Expression in Human Periodontal Ligament Cells Subjected to Orthodontic Force: An RNA-Sequencing Study

by Kyunam Kim, Hee Eun Kang, Jong In Yook, Hyung-Seog Yu, Euiseong Kim, Jung-Yul Cha and Yoon Jeong Choi

J. Clin. Med. 2020, 9(2), 358; https://doi.org/10.3390/jcm9020358 - 28 Jan 2020

Cited by 7 | Viewed by 3655

Abstract

This study was performed to investigate the changes in gene expression in periodontal ligament (PDL) cells following mechanical stimulus through RNA sequencing. In this study, premolars extracted for orthodontic treatment were used. To stimulate the PDL cells, an orthodontic force of 100× [...] Read more.

This study was performed to investigate the changes in gene expression in periodontal ligament (PDL) cells following mechanical stimulus through RNA sequencing. In this study, premolars extracted for orthodontic treatment were used. To stimulate the PDL cells, an orthodontic force of 100× g was applied to the premolar (experimental group; n = 11), whereas the tooth on the other side was left untreated (control group; n = 11). After the PDL cells were isolated from the extracted teeth, gene set enrichment analysis (GSEA), differentially expressed gene (DEG) analysis, and real-time PCR were performed to compare the two groups. GSEA demonstrated that gene sets related to the cell cycle pathway were upregulated in PDL. Thirteen upregulated and twenty downregulated genes were found through DEG analysis. Real-time PCR results confirmed that five upregulated genes (CC2D1B, CPNE3, OPHN1, TANGO2, and UAP-1) and six downregulated genes (MYOM2, PPM1F, PCDP1, ATP2A1, GPR171, and RP1-34H18.1-1) were consistent with RNA sequencing results. We suggest that, from among these eleven genes, two upregulated genes, CPNE3 and OPHN1, and one downregulated gene, PPM1F, play an important role in PDL regeneration in humans when orthodontic force is applied. Full article

(This article belongs to the Special Issue Innovations in Endodontic Dentistry)

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14 pages, 5567 KiB

Open AccessArticle

In Vitro Characterization of Dental Pulp Stem Cells Cultured in Two Microsphere-Forming Culture Plates

by Nam-Ung Bu, Hyo-Seol Lee, Bin-Na Lee, Yun-Chan Hwang, Sun-Young Kim, Seok Woo Chang, Kyoung-Kyu Choi, Duck-Su Kim and Ji-Hyun Jang

J. Clin. Med. 2020, 9(1), 242; https://doi.org/10.3390/jcm9010242 - 16 Jan 2020

Cited by 14 | Viewed by 7608

Abstract

Various three-dimensional (3D) culture methods have been introduced to overcome the limitations of in vitro culture and mimic in vivo conditions. This study aimed to evaluate two microsphere-forming culture methods and a monolayer culture method. We evaluated cell morphology, viability, osteo-, adipo-, and [...] Read more.

Various three-dimensional (3D) culture methods have been introduced to overcome the limitations of in vitro culture and mimic in vivo conditions. This study aimed to evaluate two microsphere-forming culture methods and a monolayer culture method. We evaluated cell morphology, viability, osteo-, adipo-, and chondrogenic differentiation potential of dental pulp stem cells (DPSCs) cultured in 3D culture plates: ultra-low attachment (ULA) and U-bottomed StemFit 3D (SF) plates, and a two-dimensional (2D) monolayer plate. RNA sequencing (RNA-seq) revealed differentially expressed gene (DEG) profiles of the DPSCs. In contrast to an increasing pattern in the 2D group, cell viability in 3D groups (ULA and SF) showed a decreasing pattern; however, high multilineage differentiation was observed in both the 3D groups. RNA-seq showed significantly overexpressed gene ontology categories including angiogenesis, cell migration, differentiation, and proliferation in the 3D groups. Hierarchical clustering analysis revealed a similar DEG regulation pattern between the 3D groups; however, a comparatively different DEG was observed between the 2D and 3D groups. Taken together, this study shows that DPSCs cultured in microsphere-forming plates present superior multilineage differentiation capacities and demonstrate higher DEG expression in regeneration-related gene categories compared to that in DPSCs cultured in a conventional monolayer plate. Full article

(This article belongs to the Special Issue Innovations in Endodontic Dentistry)

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9 pages, 3629 KiB

Open AccessArticle

Accuracy of Computer-Aided Dynamic Navigation Compared to Computer-Aided Static Procedure for Endodontic Access Cavities: An In Vitro Study

by Álvaro Zubizarreta-Macho, Ana de Pedro Muñoz, Elena Riad Deglow, Rubén Agustín-Panadero and Jesús Mena Álvarez

J. Clin. Med. 2020, 9(1), 129; https://doi.org/10.3390/jcm9010129 - 02 Jan 2020

Cited by 41 | Viewed by 5320

Abstract

Purpose: To analyze the accuracy of two computer-aided navigation techniques to guide the performance of endodontic access cavities compared with the conventional access procedure. Materials and Methods: A total of 30 single-rooted anterior teeth were selected, which were randomly distributed into three study [...] Read more.

Purpose: To analyze the accuracy of two computer-aided navigation techniques to guide the performance of endodontic access cavities compared with the conventional access procedure. Materials and Methods: A total of 30 single-rooted anterior teeth were selected, which were randomly distributed into three study groups: Group A—guided performance of endodontic access cavities through computer-aided static navigation system (n = 10) (SN); Group B—guided performance of endodontic access cavities through computer-aided dynamic navigation system (n = 10) (DN); and Group C—manual (freehand) performance of endodontic access cavities (n = 10) (MN). The endodontic access cavities of the SN group were performed with a stereolithography template designed on 3D implant planning software, based on preoperative cone-beam computed tomography (CBCT) and a 3D extraoral surface scan, and endodontic access cavities of the DN group were planned and performed by the dynamic navigation system. After endodontic access cavities were performed, a second CBCT was done, and the degree of accuracy between the planned and performed endodontic access cavities was analyzed using therapeutic planning software and Student’s t-test. Results: Paired t-test revealed no statistically significant differences between SN and DN at the coronal (p = 0.6542), apical (p = 0.9144), or angular (p = 0.0724) level; however, statistically significant differences were observed between the two computer-aided navigation techniques and the MN group at the coronal (p < 0.0001), apical (p < 0.0001), and angular (p < 0.0001) level. Conclusion: Both computer-aided static and dynamic navigation procedures allowed accurate performance of endodontic access cavities. Full article

(This article belongs to the Special Issue Innovations in Endodontic Dentistry)

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13 pages, 2046 KiB

Open AccessArticle

Influence of the Pecking Motion Frequency on the Cyclic Fatigue Resistance of Endodontic Rotary Files

by Álvaro Zubizarreta-Macho, Jesús Mena Álvarez, Alberto Albaladejo Martínez, Juan José Segura-Egea, Javier Caviedes Brucheli, Rubén Agustín-Panadero, Roberto López Píriz and Óscar Alonso-Ezpeleta

J. Clin. Med. 2020, 9(1), 45; https://doi.org/10.3390/jcm9010045 - 24 Dec 2019

Cited by 19 | Viewed by 3088

Abstract

Purpose: To analyze the influence of the pecking motion frequency on the cyclic fatigue resistance of endodontic rotary files. Material and Methods: Sixty PlexV 25.06 endodontic rotary files were selected and distributed into three groups: 30 movements/min (n = 20), 60 movements/min [...] Read more.

Purpose: To analyze the influence of the pecking motion frequency on the cyclic fatigue resistance of endodontic rotary files. Material and Methods: Sixty PlexV 25.06 endodontic rotary files were selected and distributed into three groups: 30 movements/min (n = 20), 60 movements/min (n = 20), and 120 movements/min (n = 20). A dynamic cyclic fatigue device was designed using Computer Aided Design/ Computer Aided Engineering (CAD/CAE) technology and manufactured by 3D impressions to simulate the pecking motion performed by an operator. Failures of the endodontic rotary files were detected by a Light-Emitting Diode (LED)/Light-Dependent Resistor (LDR) system controlled by an Arduino-Driver complex and management software. Endodontic rotary files were tested on an artificial root canal manufactured by wire electrical discharge machining (EDM), with similar dimensions to those of the instrument under examination. Endodontic rotary files were used following the manufacturer’s recommendations. The results were analyzed by ANOVA and Weibull statistics. Results: All pairwise comparisons revealed statistically significant differences in all three variables, except for the difference in the number of cycles between the groups with 60 and 120 movements/min (p = 0.298). The scale distribution parameter of Weibull statistics showed statistically significant differences in all three variables, except for the differences in the number of cycles between groups with 30 and 60 movements/min (p = 0.0722). No statistically significant differences in the three variables were observed for the shape distribution parameter. Conclusion: A low frequency of pecking motion is recommended to reduce the risk of failure of endodontic rotary files associated with cyclic fatigue. Full article

(This article belongs to the Special Issue Innovations in Endodontic Dentistry)

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18 pages, 4085 KiB

Open AccessArticle

Surface Pre-Reacted Glass Filler Contributes to Tertiary Dentin Formation through a Mechanism Different Than That of Hydraulic Calcium-Silicate Cement

by Motoki Okamoto, Manahil Ali, Shungo Komichi, Masakatsu Watanabe, Hailing Huang, Yuki Ito, Jiro Miura, Yujiro Hirose, Manabu Mizuhira, Yusuke Takahashi, Daisuke Okuzaki, Shigetada Kawabata, Satoshi Imazato and Mikako Hayashi

J. Clin. Med. 2019, 8(9), 1440; https://doi.org/10.3390/jcm8091440 - 11 Sep 2019

Cited by 14 | Viewed by 4122

Abstract

The induction of tissue mineralization and the mechanism by which surface pre-reacted glass-ionomer (S-PRG) cement influences pulpal healing remain unclear. We evaluated S-PRG cement-induced tertiary dentin formation in vivo, and its effect on the pulp cell healing process in vitro. Induced tertiary dentin [...] Read more.

The induction of tissue mineralization and the mechanism by which surface pre-reacted glass-ionomer (S-PRG) cement influences pulpal healing remain unclear. We evaluated S-PRG cement-induced tertiary dentin formation in vivo, and its effect on the pulp cell healing process in vitro. Induced tertiary dentin formation was evaluated with micro-computed tomography (μCT) and scanning electron microscopy (SEM). The distribution of elements from the S-PRG cement in pulpal tissue was confirmed by micro-X-ray fluorescence (μXRF). The effects of S-PRG cement on cytotoxicity, proliferation, formation of mineralized nodules, and gene expression in human dental pulp stem cells (hDPSCs) were assessed in vitro. μCT and SEM revealed that S-PRG induced tertiary dentin formation with similar characteristics to that induced by hydraulic calcium-silicate cement (ProRoot mineral trioxide aggregate (MTA)). μXRF showed Sr and Si ion transfer into pulpal tissue from S-PRG cement. Notably, S-PRG cement and MTA showed similar biocompatibility. A co-culture of hDPSCs and S-PRG discs promoted mineralized nodule formation on surrounding cells. Additionally, S-PRG cement regulated the expression of genes related to osteo/dentinogenic differentiation. MTA and S-PRG regulated gene expression in hDPSCs, but the patterns of regulation differed. S-PRG cement upregulated CXCL-12 and TGF-β1 gene expression. These findings showed that S-PRG and MTA exhibit similar effects on dental pulp through different mechanisms. Full article

(This article belongs to the Special Issue Innovations in Endodontic Dentistry)

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11 pages, 2181 KiB

Open AccessArticle

Differential Protein Expression in Human Dental Pulp: Comparison of Healthy, Inflamed, and Traumatic Pulp

by Wonyoung Yue, Sunil Kim, Han-Sung Jung, Jong-Min Lee, Sukjoon Lee and Euiseong Kim

J. Clin. Med. 2019, 8(8), 1234; https://doi.org/10.3390/jcm8081234 - 16 Aug 2019

Cited by 3 | Viewed by 2705

Abstract

Trauma or injury to the dental pulp causes inflammation. This study compared the proteome of healthy pulp with inflamed pulp and traumatic pulp to identify the differentially expressed proteins in the diseased state. Five participants were grouped based on the pulpal status of [...] Read more.

Trauma or injury to the dental pulp causes inflammation. This study compared the proteome of healthy pulp with inflamed pulp and traumatic pulp to identify the differentially expressed proteins in the diseased state. Five participants were grouped based on the pulpal status of the teeth: healthy, inflamed, or traumatic pulp. Pulp was extirpated and stored immediately in liquid nitrogen. Pulp tissues were subjected to 2-dimensional gel electrophoresis, and spot selection was performed. The selected spots were analyzed using liquid chromatography-tandem mass spectrometry and identified by correlating mass spectra to the proteomic databases. Fifteen spots showed increased expression in the inflamed and traumatic pulp. Annexin V, type II keratin, and hemoglobin levels were increased two-fold in the inflamed and traumatic pulp group and annexin V, mutant beta-actin, and hemoglobin were increased by ten-fold in the inflamed or traumatic pulp group, compared to levels in the healthy pulp group. Annexin V constituted two out of fifteen protein spots, and seemed to play a critical role in inhibiting inflammation and promoting the immune reaction. Further studies on this protein concerning its role in pulp repair are necessary to elucidate the underlying mechanisms. Full article

(This article belongs to the Special Issue Innovations in Endodontic Dentistry)

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8 pages, 1388 KiB

Open AccessArticle

Comparison of the Efficacy of Different Techniques for the Removal of Root Canal Filling Material in Artificial Teeth: A Micro-Computed Tomography Study

by Tuan Anh Nguyen, Yaelim Kim, Euiseong Kim, Su-Jung Shin and Sunil Kim

J. Clin. Med. 2019, 8(7), 984; https://doi.org/10.3390/jcm8070984 - 07 Jul 2019

Cited by 10 | Viewed by 3898

Abstract

This study aimed to assess the efficacy of canal filling material removal using three different techniques after filling with a Gutta–Percha (GP) cone and calcium silicate-based sealer, by measuring the percentage of volume debris of GP and sealer remaining intracanal with micro computed [...] Read more.

This study aimed to assess the efficacy of canal filling material removal using three different techniques after filling with a Gutta–Percha (GP) cone and calcium silicate-based sealer, by measuring the percentage of volume debris of GP and sealer remaining intracanal with micro computed tomography (micro-CT). The filling material was removed from 30 plastic teeth by a nickel–titanium (Ni–Ti) rotary retreatment system. Final irrigation was performed with 2 mL of saline and 10 specimens were randomly allocated to a conventional group. In the passive ultrasonic irrigation (PUI) group, ultrasonic irrigation was added to the conventional group (n = 10). In the Gentlefile Brush (GF Brush) group, irrigation with GF Brush was added to the conventional group (n = 10). Remaining filling material was measured using micro-CT imaging analysis. The total mean volume of residual filling material after retreatment in the conventional group, PUI group and GF Brush group were 4.84896 mm³, 0.80702 mm³, and 0.05248 mm³, respectively. The percentage of filling material remaining intracanal was 6.76% in the conventional group, 1.12% in the PUI group and 0.07% in the GF Brush group. This study shows that the cleaning effect of the GF Brush system is superior to those of Ni–Ti retreatment files and the PUI system in the apical area. Full article

(This article belongs to the Special Issue Innovations in Endodontic Dentistry)

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Review

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17 pages, 1546 KiB

Open AccessReview

Pulp–Dentin Tissue Healing Response: A Discussion of Current Biomedical Approaches

by Dishant Shah, Tyler Lynd, Donald Ho, Jun Chen, Jeremy Vines, Hwi-Dong Jung, Ji-Hun Kim, Ping Zhang, Hui Wu, Ho-Wook Jun and Kyounga Cheon

J. Clin. Med. 2020, 9(2), 434; https://doi.org/10.3390/jcm9020434 - 05 Feb 2020

Cited by 47 | Viewed by 9588

Abstract

Dental pulp tissue exposed to mechanical trauma or cariogenic process results in root canal and/or periapical infections, and conventionally treated with root canal procedures. The more recent regenerative endodontic procedure intends to achieve effective root canal disinfection and adequate pulp–dentin tissue regeneration; however, [...] Read more.

Dental pulp tissue exposed to mechanical trauma or cariogenic process results in root canal and/or periapical infections, and conventionally treated with root canal procedures. The more recent regenerative endodontic procedure intends to achieve effective root canal disinfection and adequate pulp–dentin tissue regeneration; however, numerous limitations are reported. Because tooth is composed of vital soft pulp enclosed by the mineralized hard tissue in a highly organized structure, complete pulp–dentin tissue regeneration has been challenging to achieve. In consideration of the limitations and unique dental anatomy, it is important to understand the healing and repair processes through inflammatory-proliferative-remodeling phase transformations of pulp–dentin tissue. Upon cause by infectious and mechanical stimuli, the innate defense mechanism is initiated by resident pulp cells including immune cells through chemical signaling. After the expansion of infection and damage to resident pulp–dentin cells, consequent chemical signaling induces pluripotent mesenchymal stem cells (MSCs) to migrate to the injury site to perform the tissue regeneration process. Additionally, innovative biomaterials are necessary to facilitate the immune response and pulp–dentin tissue regeneration roles of MSCs. This review highlights current approaches of pulp–dentin tissue healing process and suggests potential biomedical perspective of the pulp–dentin tissue regeneration. Full article

(This article belongs to the Special Issue Innovations in Endodontic Dentistry)

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