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Bone Jun 2021Dental anomalies in Osteogenesis imperfecta (OI), such as tooth discoloration, pulp obliteration (calcified dental pulp space), and taurodontism (enlarged dental pulp...
INTRODUCTION
Dental anomalies in Osteogenesis imperfecta (OI), such as tooth discoloration, pulp obliteration (calcified dental pulp space), and taurodontism (enlarged dental pulp space) vary between and within patients. To better understand the associations and variations in these anomalies, a cross-sectional study was designed to analyze the dental phenotype in OI patients at the individual tooth type.
METHOD
A cohort of 171 individuals with OI type I, III and IV, aged 3-55 years, were recruited and evaluated for tooth discoloration, pulp obliteration, and taurodontism at the individual tooth level, using intraoral photographs and panoramic radiographs.
RESULTS
Genetic variants were identified in 154 of the participants. Patients with Helical α1 and α2 glycine substitutions presented the highest prevalence of tooth discoloration, while those with α1 Haploinsufficiency had the lowest (<10%). C-propeptide variants did not cause discoloration but resulted in the highest pulp obliteration prevalence (~%20). The prevalence of tooth discoloration and pulp obliteration was higher in OI types III and IV and increased with age. Tooth discoloration was mainly observed in teeth known to have thinner enamel (i.e. lower anterior), while pulp obliteration was most prevalent in the first molars. A significant association was observed between pulp obliteration and tooth discoloration, and both were associated with a lack of occlusal contact. Taurodontism was only found in permanent teeth and affected mostly first molars, and its prevalence decreased with age.
CONCLUSION
The dental phenotype evaluation at the tooth level revealed that different genetic variants and associated clinical phenotypes affect each tooth type differently, and genetic variants are better predictors of the dental phenotype than the type of OI. Our results also suggest that tooth discoloration is most likely an optical phenomenon inversely proportional to enamel thickness, and highly associated with pulp obliteration. In turn, pulp obliteration is proportional to patient age, it is associated with malocclusion and likely related to immature progressive dentin deposition. Taurodontism is an isolated phenomenon that is probably associated with delayed pulpal maturation.
Topics: Cross-Sectional Studies; Dentinogenesis Imperfecta; Humans; Osteogenesis Imperfecta; Phenotype; Tooth
PubMed: 33741542
DOI: 10.1016/j.bone.2021.115917 -
BACH1 regulates the proliferation and odontoblastic differentiation of human dental pulp stem cells.BMC Oral Health Nov 2022The preservation of biological and physiological vitality as well as the formation of dentin are among the main tasks of human dental pulp for a life time. Odontoblastic...
BACKGROUND
The preservation of biological and physiological vitality as well as the formation of dentin are among the main tasks of human dental pulp for a life time. Odontoblastic differentiation of human dental pulp stem cells (hDPSCs) exhibits the capacity of dental pulp regeneration and dentin complex rebuilding. Exploration of the mechanisms regulating differentiation and proliferation of hDPSCs may help to investigate potential clinical applications. BTB and CNC homology 1 (BACH1) is a transcription repressor engaged in the regulation of multiple cellular functions. This study aimed to investigate the effects of BACH1 on the proliferation and odontoblastic differentiation of hDPSCs in vitro.
METHODS
hDPSCs and pulpal tissues were obtained from extracted human premolars or third molars. The distribution of BACH1 was detected by immunohistochemistry. The mRNA and protein expression of BACH1 were examined by qRT-PCR and Western blot analysis. BACH1 expression was regulated by stable lentivirus-mediated transfection. Cell proliferation and cell cycle were assessed by cell counting kit-8 assay, 5-Ethynyl-2'-deoxyuridine assay and flow cytometry. The expression of mineralization markers, alkaline phosphatase (ALP) activity and alizarin red S staining were conducted to assess the odontoblastic differentiation ability.
RESULTS
BACH1 expression was stronger in the odontoblast layer than in the cell rich zone. The total and nuclear protein level of BACH1 during odontoblastic differentiation was downregulated initially and then upregulated gradually. Knockdown of BACH1 greatly inhibited cell proliferation, arrested cell cycle, upregulated the heme oxygenase-1 (HO-1) expression and attenuated ALP activity, decreased calcium deposits and downregulated the expression of mineralization markers. Treatment of Tin-protoporphyrin IX, an HO-1 inhibitor, failed to rescue the impaired odonto/osteogenic differentiation capacity. Overexpression of BACH1 increased cell proliferation, ALP activity and the expression of mineralization markers.
CONCLUSIONS
Our findings suggest that BACH1 is an important regulator of the proliferation and odontoblastic differentiation of hDPSCs in vitro. Manipulation of BACH1 expression may provide an opportunity to promote the regenerative capacity of hDPSCs.
Topics: Humans; Basic-Leucine Zipper Transcription Factors; Cell Proliferation; Dental Pulp; Osteogenesis; Regeneration; Stem Cells
PubMed: 36424585
DOI: 10.1186/s12903-022-02588-2 -
Connective Tissue Research Jan 2023Previous studies demonstrated that the exposure of primary dental pulp (DP) cultures to fibroblast growth factor 2 (FGF2) between days 3-7 exerted significant and...
PURPOSE
Previous studies demonstrated that the exposure of primary dental pulp (DP) cultures to fibroblast growth factor 2 (FGF2) between days 3-7 exerted significant and long-lasting stimulatory effects on odontoblast differentiation and expression. These effects involved the increased expression of components of bone morphogenetic protein (BMP) signaling and were reverted by a BMP inhibitor noggin. FGF2 also transiently stimulated osteoblast differentiation and the expression of and . The present study aimed to further explore interactions between BMP and FGF signaling during odontoblast and osteoblast differentiation in DP cultures.
MATERIALS AND METHODS
Cultures were established using DP tissue isolated from non-transgenic and fluorescent reporter (DSPP-Cerulean, BSP-GFP, and DMP1-mCherry) transgenic mice and exposed to BMP2, FGF2, SU5402 (an FGF receptor inhibitor), and noggin between days 3-7. Mineralization, gene expression, fluorescent protein expression, and odontoblast formation were examined using xylenol orange, quantitative PCR, fluorometric analysis, and immunocytochemistry, respectively.
RESULTS
BMP2 activated SMAD1/5/8 but not ERK1/2 signaling, whereas FGF2 exerted opposite effects. BMP2 did not affect mineralization, the expression of and , and the percentage of DSPP-Cerulean+ odontoblasts but significantly increased and DSPP-Cerulean. In cultures exposed to BMP2 and FGF2, respectively, both SU5402 and noggin led to long-lasting decreases in and DSPP-Cerulean and transient decreases in and DMP1-mCherry without affecting and BSP-GFP.
CONCLUSION
BMP2 and FGF2 exerted reciprocal stimulatory effects on odontoblast differentiation, whereas their effects on osteoblast differentiation were mediated independently. These data will further elucidate the perspectives of using BMP2 and FGF2 for dentin regeneration/repair.
Topics: Mice; Animals; Odontoblasts; Fibroblast Growth Factor 2; Mice, Transgenic; Extracellular Matrix Proteins; Cell Differentiation; Signal Transduction; Phosphoproteins; Sialoglycoproteins
PubMed: 35816114
DOI: 10.1080/03008207.2022.2094789 -
Journal of Dental Research Apr 2020Mutations in cause X-linked hypophosphatemia (XLH), a form of hypophosphatemic rickets. ( mutant) mice recapitulate the XLH phenotype. Dental disorders are prevalent...
Mutations in cause X-linked hypophosphatemia (XLH), a form of hypophosphatemic rickets. ( mutant) mice recapitulate the XLH phenotype. Dental disorders are prevalent in individuals with XLH; however, underlying dentoalveolar defects remain incompletely understood. We analyzed mouse dentoalveolar defects at 42 and 90 d postnatal to comparatively define effects of XLH on dental formation and function. mRNA was expressed by odontoblasts (dentin), osteocytes (bone), and cementocytes (cellular cementum) in wild-type (WT) mice. Enamel density was unaffected, though enamel volume was significantly reduced in mice. Dentin defects in molars were indicated histologically by wide predentin, thin dentin, and extensive interglobular dentin, confirming micro-computed tomography (micro-CT) findings of reduced dentin volume and density. Acellular cementum was thin and showed periodontal ligament detachment. Mechanical testing indicated dramatically altered periodontal mechanical properties in versus WT mice. mandibles demonstrated expanded alveolar bone with accumulation of osteoid, and micro-CT confirmed decreased bone volume fraction and alveolar bone density. Cellular cementum area was significantly increased in versus WT molars owing to accumulation of hypomineralized cementoid. Histology, scanning electron microscopy, and nanoindentation revealed hypomineralized "halos" surrounding cementocyte and osteocyte lacunae. Three-dimensional micro-CT analyses confirmed larger cementocyte/osteocyte lacunae and significantly reduced perilacunar mineral density. While long bone and alveolar bone osteocytes in mice overexpressed fibroblast growth factor 23 (), its expression in molars was much lower, with cementocyte expression particularly low. Expression and distribution of other selected markers were disturbed in versus WT long bone, alveolar bone, and cementum, including osteocyte/cementocyte marker dentin matrix protein 1 (). This study reports for the first time a quantitative analysis of the mouse dentoalveolar phenotype, including all mineralized tissues. Novel insights into cellular cementum provide evidence for a role for cementocytes in perilacunar mineralization and cementum biology.
Topics: Animals; Calcification, Physiologic; Familial Hypophosphatemic Rickets; Female; Fibroblast Growth Factor-23; Hypophosphatemia; Male; Mice; Mice, Inbred BALB C; PHEX Phosphate Regulating Neutral Endopeptidase; X-Ray Microtomography
PubMed: 31977267
DOI: 10.1177/0022034520901719 -
Heliyon Feb 2021Surface pre-reacted glass-ionomer (S-PRG) fillers release antibacterial borate and fluoride ions. We fabricated nanoscale S-PRG fillers (S-PRG nanofillers) for...
OBJECTIVES
Surface pre-reacted glass-ionomer (S-PRG) fillers release antibacterial borate and fluoride ions. We fabricated nanoscale S-PRG fillers (S-PRG nanofillers) for antibacterial coating of tooth surfaces and assessed the antibacterial effects of this coating in vitro. In addition, we creating a canine model of periodontitis to evaluate the effectiveness of S-PRG nanofiller application on tooth roots and improvement of periodontal parameters.
METHODS
Human dentin blocks were coated with S-PRG nanofiller (average particle size: 0.48 μm) and then characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDX), and ion-releasing test. Antibacterial effects of dentin blocks coated with S-PRG nanofiller were examined using bacterial strains, and Next, we created an experimental model of periodontitis in furcation of premolars of beagle dogs. Then, S-PRG nanofiller coating was applied onto exposed tooth root surfaces. Periodontal parameters, gingival index (GI), bleeding on probing (BOP), probing pocket depth (PPD), and clinical attachment level (CAL), were measured from baseline until 4 weeks. In addition, bone healing was radiographically and histologically examined.
RESULTS
SEM and EDX revealed that S-PRG nanofillers uniformly covered the dentin surface after coating. Dentin blocks coated with S-PRG nanofiller showed ion-releasing property, bacterial growth inhibition, and sterilization effects. In the experimental periodontitis model, S-PRG nanofiller coating significantly reduced clinical inflammatory parameters, such as GI (P < 0.01) and BOP (P < 0.05), compared to uncoated samples. In addition, PPD and CAL significantly decreased by S-PRG nanofiller coating (2 weeks: P < 0.05; 3 and 4 weeks: P < 0.01), suggesting the improvement of periodontitis. Micro-CT and histology revealed that bone healing of furcation defects was enhanced by S-PRG nanofiller coating.
CONCLUSION
S-PRG nanofiller coating provides antibacterial effects to tooth surfaces and improves clinical parameters of periodontitis.
PubMed: 33644453
DOI: 10.1016/j.heliyon.2021.e06147 -
Dental Materials : Official Publication... May 2024To evaluate the effects of an ammonia-based and a water-based silver-containing solutions on bonding performance and matrix-metalloproteinases (MMPs) activity of a... (Comparative Study)
Comparative Study
OBJECTIVE
To evaluate the effects of an ammonia-based and a water-based silver-containing solutions on bonding performance and matrix-metalloproteinases (MMPs) activity of a universal adhesive to dentin after 1 year of artificial aging.
METHODS
Mid-coronal dentin surfaces of 60 sound human molars were exposed and the following groups were formed according to the surface pre-treatment and etching mode of the universal adhesive (Zipbond Universal, SDI) (n = 10): G1) Zipbond in the self-etch mode (ZSE); G2) Riva Star (SDI) applied before ZSE; G3) Riva Star Aqua (SDI) applied before ZSE; G4) Zipbond in the etch-and-rinse mode (ZER); G5) Riva Star applied before ZER; G6) Riva Star Aqua applied before ZER. The specimens were sectioned and subjected to microtensile bond strength (µTBS) test at baseline (T) and after 12 months (T) of artificial storage. Scanning electron microscope (SEM) and energy dispersive spectroscopy analysis (EDS) were also conducted. Three additional molars per group were processed for the in situ zymography analysis at T and T. Data were statistically analyzed (p < 0.05).
RESULTS
Dentin pre-treatments and aging decreased bonding values, regardless of the etching mode (p < 0.05). No differences in µTBS were observed between the two silver-containing solutions, both at T and T. Riva Star Aqua and etching significantly increased the MMPs activity, independent of the storage period (p < 0.05).
SIGNIFICANCE
Dentin surface pre-treatment with silver-containing solutions negatively affects the bonding performances of resin composite restorations placed with a universal adhesive. However, the ammonia-based product Riva Star might show better stability in the long term, due to lower activation of MMPs.
Topics: Humans; Water; Dental Bonding; Dentin-Bonding Agents; Materials Testing; Silver; Ammonia; Microscopy, Electron, Scanning; Tensile Strength; Surface Properties; Dentin; In Vitro Techniques; Matrix Metalloproteinases; Resin Cements; Molar; Acid Etching, Dental; Spectrometry, X-Ray Emission; Dental Stress Analysis
PubMed: 38458917
DOI: 10.1016/j.dental.2024.03.003 -
Journal of Dental Sciences Jul 2023The most widely utilized irrigation solution in endodontic therapy is sodium hypochlorite (NaOCl). The purpose of this study was to assess the effects of NaOCl on the...
ABSTRACT BACKGROUND/PURPOSE
The most widely utilized irrigation solution in endodontic therapy is sodium hypochlorite (NaOCl). The purpose of this study was to assess the effects of NaOCl on the bond strength of four universal adhesives and one two-step self-etch adhesive to pulp chamber dentin.
MATERIALS AND METHODS
One hundred sixteen extracted sound human third molars were used in this study. All the teeth were divided into two groups: (1) with NaOCl treatment and (2) without NaOCl treatment. These two groups were subdivided into five bonding groups: G-Premio Bond (GP), Beautibond Xtreme (BBX), Scotchbond Universal (SBU), Clearfil Universal Bond Quick (UBQ), and Clearfil Megabond 2 (MB2). The microtensile bond strength (μTBS), the fracture mode analysis, resin-dentin interface and dentin surface were observed by SEM. Two-way ANOVA was performed to analyze the μTBS (α = 0.05).
RESULTS
The μTBS of the NaOCl group significantly decreased for GP and MB2 ( < 0.05). Significant effects of adhesive (F = 12.182, < 0.001), and irrigation (F = 27.224, < 0.001) on the μTBS were observed, whereas interaction between adhesive and irrigation was not significant (F = 1.761, = 0.144). The adhesive layer with variable thickness was observed in all groups with different morphological structures.
CONCLUSION
The effect of NaOCl treatment on the μTBS differs depending on the type of adhesives.
PubMed: 37404671
DOI: 10.1016/j.jds.2022.11.007 -
Journal of Conservative Dentistry : JCD 2022Despite constant advances in science, obscurity remains in the efficient removal of pulp stones to aid in successful root canal treatment. In this context, chemical...
BACKGROUND
Despite constant advances in science, obscurity remains in the efficient removal of pulp stones to aid in successful root canal treatment. In this context, chemical means of dissolving pulp stones were explored.
AIM
The aim of this study is to evaluate and to compare the efficacy of decalcifying agents on the dissolution of pulp stones.
MATERIALS AND METHODS
The study was divided into two groups for pulp stone analysis (21 samples) and dentin analysis (54 samples). Twenty-one pulp stones from patients aged 18-70 who underwent root canal treatment were collected and divided into three subgroups ( = 7) randomly. They were subjected to chemical treatment in a labeled glass container with 5 ml of the respective chemical agents, such as 17% ethylenediaminetetraacetic acid solution (positive control), no treatment (negative control), and newly developed Physiological Simulated Decalcifying Agent (PSDA). At the end of the study period (24 h), the samples were removed, rinsed with deionized water, and subjected to physical analysis, scanning electron microscopy (SEM), and Energy -dispersive X-ray spectroscopy (EDS) analysis. Under dentin analysis, 54 maxillary premolars scheduled for orthodontic extraction without caries or extensive restorations were selected, following which 2-mm thick transverse dentinal sections at the cementoenamel junction level were obtained and randomly divided into two groups for SEM ( = 21) and microhardness analysis ( = 33). The samples were subjected to respective chemical treatment groups similar to pulp stones for 24 h and analyzed using SEM, EDS, and microhardness analysis.
RESULTS
Postchemical treatment with the newly developed decalcifying solution, the pulp stones showed the absence of nodular crystallites and surface softening under SEM and a decrease in the calcium level under EDS analysis. Concerning the microhardness of dentin, no significant changes could be observed.
CONCLUSION
The newly explored PSDA was found to be efficacious in the decalcification of pulp stones at a clinically relevant time of 24 h, without significantly affecting the structural integrity and the hardness values of dentin.
PubMed: 36187864
DOI: 10.4103/jcd.jcd_35_22 -
BMC Oral Health Jul 2022Relatively high incidence of single canals with oval or round shape were observed in human mandibular incisors. In order to investigate the influence of the root canal...
BACKGROUND
Relatively high incidence of single canals with oval or round shape were observed in human mandibular incisors. In order to investigate the influence of the root canal morphology on root canal preparation, the shaping outcome of ProTaper NEXT in oval and round canals of mandibular incisors were evaluated by using micro-computed tomography (micro-CT) analysis.
METHODS
This experiment was approved by the School Medical Ethics Committee. The sample size calculation was conducted using G*Power software. Intact mandibular incisors with a single canal were selected. Oval canals (2 < aspect ratio (AR) ≤ 4) and round canals (AR ≤ 2) were pair-matched according to canal length, and assigned to two experimental groups (13 per group). ProTaper NEXT was used for root canal preparation for both groups. Untouched canal wall (UCW), root canal morphological parameters and three-dimensional (3D) dentin thickness were evaluated in the entire root canal and each canal third after micro-CT scanning.
STATISTICAL ANALYSIS
Data were collected and analyzed with Mann-Whitney test and Friedman test using SPSS statistics software 25 (P < 0.05). Additionally, correlations of UCW area with canal morphological parameters were also investigated.
RESULTS
After root canal preparation, no significant difference was observed in all analyzed parameters in the apical third between oval and round canal groups (P > 0.05). In the coronal two thirds of the canal, the post-operative structure model index (SMI), form factor and roundness were significantly increased, while the AR was significantly decreased in both groups (P < 0.05). In addition, in the coronal two thirds, significantly more UCW and higher UCWΔ% was observed in oval canal group (P < 0.05). Furthermore, UCW correlated very strongly to canal major diameter (0.924) and initial volume (0.938), and strongly to canal form factor (- 0.724), minor diameter (0.799) and canal area (0.882). Proximal dentin wall was associated with significantly thinner pre-operative dentin thickness and higher amount of dentin removal after root canal preparation in both oval and round canal groups.
CONCLUSIONS
(1) Both types of canals were more conical after root canal preparation, but oval root canals tend to leave more UCW area than round canals in the coronal two thirds of mandibular incisors, which contributes to the challenge for endodontic infection control. (2) Root canal preparation usually results in excessive dentin removal in the proximal dentin wall comparing with buccal and lingual walls in both types of canals of mandibular incisors.
Topics: Dental Pulp Cavity; Humans; Incisor; Molar; Root Canal Preparation; X-Ray Microtomography
PubMed: 35869473
DOI: 10.1186/s12903-022-02335-7 -
Journal of Functional Biomaterials May 2024The aim of this study was to evaluate the effect of different irrigating solutions as well as their combination and activation modes on root canal dentin microhardness.... (Review)
Review
The aim of this study was to evaluate the effect of different irrigating solutions as well as their combination and activation modes on root canal dentin microhardness. The protocol was registered in PROSPERO and PRISMA guidelines were followed. The structured question was as follows: "Which type of irrigating solution used in endodontic treatment causes more change in dentin microhardness?" The literature was screened via PubMed, Google Scholar, Scopus, and Science Direct. The last search was carried out in February 2023 with English language restriction. Two reviewers independently performed screening and evaluation of articles. A total of 470 articles were retrieved from all the databases, whereas only 114 articles were selected for full-text analysis. After applying eligibility criteria, 44 studies were evaluated and included in this review. The results showed that with increased contact time with irrigants, dentin microhardness decreases. Increased contact time with sodium hypochlorite (NaOCl) was associated with more reduction in dentin microhardness compared with other irrigants. Other irrigants, with the exception of distilled water, including EDTA, citric acid, herbal irrigants, glycolic acid, phytic acid, etc., in this study significantly decreased dentin microhardness. The maximum reduction in dentin microhardness was seen with 2.5% NaOCl after 15 min of contact time. The use of irrigating solutions alters the chemical composition of dentin, thereby decreasing its microhardness, which affects the clinical performance of endodontically treated teeth.
PubMed: 38786643
DOI: 10.3390/jfb15050132