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Elfarraj H, Lizzi F, Bitter K, Zaslansky P. Effects of endodontic root canal irrigants on tooth dentin revealed by infrared spectroscopy: a systematic literature review. Dent Mater 2024:S0109-5641(24)00113-1. [PMID: 38825554 DOI: 10.1016/j.dental.2024.05.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 04/17/2024] [Accepted: 05/13/2024] [Indexed: 06/04/2024]
Abstract
BACKGROUND Root canal irrigation endodontic solutions have effects on the chemistry of dentin. Infrared spectroscopy is a non-destructive chemical characterization method where the strength of absorption often correlates with mineral or organic composition. OBJECTIVES To survey effects of commonly used irrigation solutions on the composition of root dentin as detected by widely-available Fourier transform infrared spectroscopy (FTIR) methods. METHODS Electronic databases were searched for articles published between 1983 to 2023. After risk of bias assessments (OHAT), studies were grouped according to effects per irrigation solution. Inclusion criteria comprised in vitro studies that used extracted human or bovine teeth, treated by irrigation solutions characterized using FTIR spectroscopy and presenting spectral data. Publications that did not share FTIR spectra were excluded. RESULTS A wide range of concentrations, durations, and methodologies have been tested but only 30 out of 3452 studies met our inclusion criteria. Different FTIR methods were used with the Attenuated Total Reflection (ATR) variant being the most common (21 studies). Investigated solutions included sodium hypochlorite (NaOCl), ethylenediaminetetraacetic-acid (EDTA), 1-hydroxyethylidene-1-1-diphosphonic-acid (HEDP), peracetic-acid (PAA), glycolic-acid (GA), and citric-acid (CA) though most focused on NaOCl and EDTA. All solutions had detectable effects on the FTIR signature of dentin. NaOCl mainly affects the organic signatures, revealing reduced amide/phosphate ratios with increasing concentrations. EDTA mainly effects the inorganic component, increasing with time and concentration, yet glycolic acid has stronger effects than EDTA on dentin. Beyond the type of irrigant and dentin exposure durations, concentration and protocol of application had strong effects. There is a lack of studies comparing similar irrigants under conditions that mimic clinical scenarios analyzing bulk sample because FTIR of powder dentin differs from bulk measurements. SIGNIFICANCE The ideal root-canal irrigant should combine local disinfection properties with minimal compositional effects on healthy dentin. FTIR methods appear reliable to identify important changes in root dentin chemical composition. Such information can help understand when endodontic irrigation might lead to root degradation or possibly contribute to long term failures such as vertical fractures. Awareness of chemical damage from irrigation procedures may help clinicians select procedures that reduce deleterious effects on the root canal structures.
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Affiliation(s)
- Hamza Elfarraj
- Department of Operative, Preventive and Pediatric Dentistry, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin und Humboldt-Universität zu Berlin, Berlin, Germany.
| | - Franco Lizzi
- Department of Operative, Preventive and Pediatric Dentistry, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin und Humboldt-Universität zu Berlin, Berlin, Germany
| | - Kerstin Bitter
- University Outpatient Clinic for Operative Dentistry and Periodontology, Martin-Luther-University, Halle-Wittenberg, Germany
| | - Paul Zaslansky
- Department of Operative, Preventive and Pediatric Dentistry, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin und Humboldt-Universität zu Berlin, Berlin, Germany
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Fitzgerald JM, Souza GD, Tam L. Effect of Tooth Bleach on Dentin Fatigue Resistance in Situ. Oper Dent 2023; 48:638-647. [PMID: 37881145 DOI: 10.2341/22-093-c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/10/2023] [Indexed: 10/27/2023]
Abstract
BACKGROUND Negative effects of bleaching on dentin have previously been reported in vitro. OBJECTIVE The purpose of this study was to determine the effect of carbamide peroxide bleaching on dentin fatigue resistance using a clinically relevant in situ model. METHODS AND MATERIALS Following research ethics board approval, 60 human teeth requiring extraction were collected. Sterilized human dentin specimens were cut (1.2x1.2x10 mm) and secured into customized bleaching trays to be used by study participants. Participants were randomly assigned to either bleach (10% carbamide peroxide, n=23) or control (gel without bleach, n=26) treatment groups. Treatment was applied to the bleaching trays and worn overnight by participants for 14 days. After treatment completion, dentin specimens were removed from the bleaching trays and subjected to fatigue testing (10 N, 3 mm/s, 2x105 cycles) while submerged in artificial saliva. Kaplan-Meier survival analysis was conducted to compare the number of cycles to failure during fatigue testing in both groups. A log rank test was run to determine if there were differences in the survival distribution between the two groups (α<0.05). RESULTS The median number of cycles to failure was 352 ± 202 and 760 ± 644 for the bleach and control groups, respectively. The survival distributions for the two groups were significantly different (p=0.020). Dentin fatigue resistance was significantly lower in the bleach group compared to the control. CONCLUSIONS Direct bleaching of human dentin using an at-home tray bleaching protocol in situ reduced dentin fatigue resistance. This has implications for tooth fracture risk and longevity.
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Affiliation(s)
- J M Fitzgerald
- *Jacob M Fitzgerald, DDS, MSc, University of Toronto Faculty of Dentistry, Toronto, Ontario, Canada
| | - G De Souza
- Grace De Souza DDS, MSc, PhD, FADM, University of Louisville, Louisville, KY, USA
| | - L Tam
- Laura Tam, DDS, MSc, University of Toronto, Toronto, Ontario, Canada
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Marchand E, Bertrand B, Hedouin V, Demondion X, Becart A. Study of Root Transparency in Different Postmortem Intervals Using Scanning Electron Microscopy. Diagnostics (Basel) 2023; 13:2808. [PMID: 37685346 PMCID: PMC10487109 DOI: 10.3390/diagnostics13172808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 08/23/2023] [Accepted: 08/25/2023] [Indexed: 09/10/2023] Open
Abstract
In the fields of forensics, the identification of human remains is a recurrent problem. The estimated age at death is one of the copious criteria to be evaluated. In adult teeth, the height of the root dentin transparency is used to estimate age. However, in archaeological material, this phenomenon appears inconstant. The aim of this work was to observe the structural modifications of the sclerotic dentin in the teeth for different postmortem intervals. The study included two parts (retrospective and prospective study) with 21 human monoradicular teeth, from bodies donated to medical science with postmortem intervals (PMIs) of 0, 1, 2 and 5 years and archeological excavation. After inclusion based on resin, section and polishing, the samples were analyzed with a scanning electron microscope (SEM) JSM-7800F®, and the procedure was completed via a semiquantitative analysis of calcium and phosphorus using EDX microanalysis. The analysis showed the existence of tubular and chemical modifications of sclerotic dentin at different PMIs. Our SEM study allowed us to observe a difference in tubule aspects linked to an increased PMI: the loss of peritubular collar and the lumen obstruction of tubules with a hyperdense material. Microanalysis highlighted variations in phosphocalcic ratios among the different groups, especially in the pulp area and the canine. Our hypotheses that explain these differences are based on the postmortem modifications of the crystals of the mineral phase of sclerotic dentin under the influence of chemical and/or bacterial action.
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Affiliation(s)
- Elodie Marchand
- Unité de Taphonomie Médico-Légale et Anatomie, ULR 7367, Faculté de Médecine, Université de Lille, 59000 Lille, France (A.B.)
- CHRU Nancy, Service de Médecine Légale, 54000 Nancy, France
| | - Benoit Bertrand
- Unité de Taphonomie Médico-Légale et Anatomie, ULR 7367, Faculté de Médecine, Université de Lille, 59000 Lille, France (A.B.)
- Muséum National d’Histoire Naturelle, Département Homme et Environnement, UMR 7194—HNHP, Institut de Paléontologie Humaine, 75013 Paris, France
| | - Valéry Hedouin
- Unité de Taphonomie Médico-Légale et Anatomie, ULR 7367, Faculté de Médecine, Université de Lille, 59000 Lille, France (A.B.)
| | - Xavier Demondion
- Unité de Taphonomie Médico-Légale et Anatomie, ULR 7367, Faculté de Médecine, Université de Lille, 59000 Lille, France (A.B.)
| | - Anne Becart
- Unité de Taphonomie Médico-Légale et Anatomie, ULR 7367, Faculté de Médecine, Université de Lille, 59000 Lille, France (A.B.)
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Navarro-Cerón A, Barceló-Santana FH, Vera-Graziano R, Rivera-Torres F, Jiménez-Ávila A, Rosales-Ibáñez R, Navarro-Cerón E, Castell-Rodríguez AE, Maciel-Cerda A. Bovine dentin collagen/poly(lactic acid) scaffolds for teeth tissue regeneration. IRANIAN POLYMER JOURNAL 2023. [DOI: 10.1007/s13726-023-01139-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
AbstractElectrospun scaffolds with diameter fibers compared to those in the extracellular matrix were produced with poly(lactic acid) (PLA) and non-denatured collagen from bovine dentin (DCol). DCol was obtained through an improved version of the Longin method by acid erosion of the hydroxyapatite of the roots of teeth from a 2-year-old cattle. The dentin collagen was characterized by energy dispersive X-ray spectroscopy (EDS), and carbon, nitrogen, and oxygen were found to be the main elements of the protein. Infrared analysis revealed the typical bands of collagen at about 3300, 1631, 1539, and 1234 cm−1 for amides A, I, II, and III, respectively. Calorimetric and infrared analyses also demonstrated that the collagen was non-denatured. With scanning electron microscopy, it was found that the thinnest fibers with a diameter comparable to that of fibers in the extracellular matrix were obtained when dentin collagen and acetic acid (AAc) were added to the solution of PLA in trifluoroethanol (TFE). The scaffolds with the thinnest diameter had also the highest porosity, and we considered that they could be beneficial in the growth of dentin cell. Human placenta-derived mesenchymal stem cells were seeded onto electrospun scaffolds. After 24, 48 and 96 h of culture, cell proliferation was evaluated by two independent strategies. In both assays, it was found that the pl-MSCs were capable of adhering and proliferating in different scaffolds. It was also observed that cell adhesion and proliferation increased significantly in scaffolds containing collagen, although the addition of AAc slightly decreased this effect on all scaffolds.
Graphical abstract
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Effect of Method of Removing Caries-Affected Dentin on the Bond Strength of Composite Resin to Root Canal Dentin. Healthcare (Basel) 2022; 10:healthcare10112143. [PMID: 36360483 PMCID: PMC9691166 DOI: 10.3390/healthcare10112143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 10/18/2022] [Accepted: 10/26/2022] [Indexed: 11/17/2022] Open
Abstract
The adhesion of composite resin to caries-affected dentin differs from the adhesion of resin to sound dentin. We evaluated the bond strengths of dual-cure resin composites applied to caries-affected root canal dentin under various clinical conditions and using several caries removal indicators. In the dye stain 1 group, caries were removed to a pale pink stain level using a caries detector. In the dye stain 2 group, caries were removed to a stain-free level using a caries detector. In the probing group, caries were removed to the level of hardness based on probing with a sharp explorer. Additionally, a sound dentin group was used as a control. We compared the resin composite microtensile bond strengths and failure mode distribution among the groups. The bond strengths (MPa) of the probing (64.6 ± 11.9) and the sound dentin (68.7 ± 11.1) groups were significantly higher than those of the dye stain 1 (46.9 ± 7.9) and 2 (47.5 ± 8.4) groups (p < 0.05). The removal of caries-affected dentin using a dentin-hardness-based technique showed higher tensile strength than that using a dye stain technique involving removal to any color level. Thus, the caries removal technique used on root canal dentin affects the bond strength of the resin composite.
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In Vitro Analysis of Organic Ester Functional Groups in Carious Dentine. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12031088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
Background: With the implementation of minimally invasive selective caries removal protocols to treat cavitated, deep carious dentine lesions, there is a need to investigate specific biochemical moiety distributions to help characterise and distinguish between infected (contaminated) and affected (demineralised) zones within the dentine lesion. The present in vitro investigation aimed to compare the distribution of ester functional groups (1740 cm−1) within carious dentine tissue (infected and affected dentine). The null hypothesis stipulated that there are no differences in ester function intensity/distribution within carious dentine lesions. Materials and Methods: From a total of five extracted human molar teeth with carious dentine lesions, 246 points from 10 sections of carious dentine were examined using high-resolution Raman spectroscopy and characterised into infected, affected and sound dentine. The peak intensity of the characteristic vibration mode of the ester function was calculated from sample scans. Results: Analyses indicated a statistically significant difference in the spectroscopic vibration bands of esters between the infected and affected dentine zones. Conclusion: The ester functional group is higher in intensity in the caries-infected dentine zone compared to the affected tissue. This finding could be used to develop an objective indicator for the selective operative management of carious dentine.
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Nishimaki M, Nassar M, Tamura Y, Hiraishi N, Dargham A, Nikaido T, Tagami J. The effect of surface pre-reacted glass-ionomer filler eluate on dental pulp cells and mineral deposition on dentin: In vitro study. Eur J Oral Sci 2021; 129:e12777. [PMID: 33724553 DOI: 10.1111/eos.12777] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 12/13/2020] [Accepted: 01/25/2021] [Indexed: 11/28/2022]
Abstract
The effects of surface pre-reacted glass-ionomer (S-PRG) filler on pulpal cells and on the composition of dentinal deposits were investigated. Proliferation (CCK-8), cytotoxicity (LDH), and differentiation activity (ALP) tests, along with cell morphology observations, were conducted at 6 and 24 h after treatment of pulpal cells with different S-PRG filler eluate concentrations. Dentinal surfaces were immersed in deionized water or S-PRG filler eluate followed by immersion in deionized water or simulated body fluid and observed under scanning electron microscope and elemental analysis using energy dispersive x-ray spectrometer. At 24 h, there were significant differences in CCK-8 and ALP activity values between the groups in a concentration-dependent manner. LDH test data were not significantly different among the groups. Cell morphology was not altered at either exposure time. However, decreased cellular density was observed with the highest eluate concentration. Crystalline deposits and occluded dentinal tubules were observed in samples immersed in S-PRG filler with a later immersion in simulated body fluid, which also showed higher concentrations of certain ions compared to surfaces that were not initially treated with S-PRG filler. The lowest two eluate concentrations did not show significant toxicity. S-PRG enhanced the effect of simulated body fluid in the formation of mineral deposits.
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Affiliation(s)
- Mayuri Nishimaki
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Mohannad Nassar
- Department of Preventive and Restorative Dentistry, College of Dental Medicine, University of Sharjah, Sharjah, United Arab Emirates
| | - Yukihiko Tamura
- Department of Bio-Matrix (Dental Pharmacology), Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Noriko Hiraishi
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Ahmad Dargham
- Ras Al Khaimah College of Dental Sciences, Ras Al Khaimah Medical and Health Sciences University, Ras Al Khaimah, United Arab Emirates
| | - Toru Nikaido
- Department of Operative Dentistry, Division of Oral Functional Sciences and Rehabilitation, School of Dentistry, Asahi University, Gifu, Japan
| | - Junji Tagami
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
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Kuntze MM, Mendes Souza BD, Schmidt TF, de Almeida J, Bortoluzzi EA, Felippe WT. Scanning electron microscopy evaluation of dentin ultrastructure after surface demineralization. J Conserv Dent 2021; 23:512-517. [PMID: 33911362 PMCID: PMC8066673 DOI: 10.4103/jcd.jcd_102_19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 04/10/2020] [Accepted: 06/26/2020] [Indexed: 12/03/2022] Open
Abstract
Context: Knowledge about dentin microstructure is essential for execution of clinical procedures which require adhesion of materials to dentin. Aims: To evaluate by scanning electron microscopy (SEM) the dentin ultrastructure after demineralization with 6 M and 12 M hydrochloric acid (HCl). Subjects and Methods: Twenty dentin segments were immersed in fixative solution and dehydrated in ethanol. After 24 h, segments were randomly divided into 2 groups (n = 10), demineralized with 6 M HCl (G6M) and 12 M HCl (G12M), and prepared for SEM analysis. Statistical Analysis Used: Based on photomicrographs and chemical composition (energy dispersive X-ray spectroscopy) of dentin, a descriptive analysis was conducted. Results: G6M samples revealed a demineralized surface with peritubular dentin exposure and small magnification of the dentinal tubules openings. The intertubular dentin was partially demineralized. Demineralization of G12M samples was more aggressive and at different depths, promoting erosion and “detachment” of dentin layers. Peritubular dentin was observed on the dentin surface. There was a large magnification of the dentinal tubules openings. In both groups, tubular structures showed a similar chemical composition to the intertubular dentin. Lamina limitans was not observed. Conclusions: Dentin demineralization is dependent on the HCl molarity and promotes exposure of peritubular dentin.
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Affiliation(s)
- Morgane Marion Kuntze
- Department of Dentistry, Federal University of Santa Catarina, Florianópolis, Brazil
| | | | | | - Josiane de Almeida
- Department of Endodontics, University of Southern Santa Catarina, Palhoça, Santa Catarina, Brazil
| | | | - Wilson Tadeu Felippe
- Department of Dentistry, Federal University of Santa Catarina, Florianópolis, Brazil
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Fleck C, Burke M, Ganzosch G, Müller C, Currey JD, Zaslansky P. Breaking crown dentine in whole teeth: 3D observations of prevalent fracture patterns following overload. Bone 2020; 132:115178. [PMID: 31816420 DOI: 10.1016/j.bone.2019.115178] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Revised: 11/04/2019] [Accepted: 11/26/2019] [Indexed: 12/19/2022]
Abstract
Teeth with intact crowns rarely split or fracture, despite decades of cyclic loading and occasional unexpected overload. This is largely attributed to the presence of dentine, since cracking and fracture of enamel have been frequently reported. Dentine is similar to bone, comprising mineralised collagen fibres as a main constituent. Unlike cortical bone, however, where microcracking and damage arrest are essential for re/modelling and healing, dentine can neither remodel nor regenerate. This raises questions regarding the evolutionary benefits of toughening, leading to uncertainty whether cracks actually appear in dentine in situ. Here we study the notion that circumpulpal dentine is usually protected against, rather than damaged by severe overloads, even though it is not much more massive or stronger than it needs to be. To address this, we examined hydrated teeth still within whole jawbones of freshly-slaughtered skeletally mature pigs, mechanically loaded until fracture. Force displacement curves, optical and electron microscopy combined with 3D microstructural analysis by conventional micro-computed tomography (μCT) revealed mostly brittle fracture paths in circumpulpal crown dentine. Once overload cracks reach this mass of dentine they propagate rapidly along straight paths often parallel to the enamel flanks of the oblong shovel shaped premolars. We find infrequent signs of active toughening mechanisms with minimal crack diversion, ligament bridging and microcracking. When such toughening is seen, it mainly appears in softer dentine in the root, or near the dentine-enamel-junction (DEJ) in mantle dentine. We observed shear bands in overloaded circumpulpal dentine, due to mutual gliding of upper and lower segments. These shear bands are formed as periodic arrays of rotated dentine fragments. The 3D data consistently demonstrate the importance of the layered tooth structure, containing a stiff outer enamel shell, a soft sub-DEJ interlayer and a stiff circumpulpal dentine bulk, for deflecting cracks from splitting the tooth.
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Affiliation(s)
- Claudia Fleck
- Technische Universität Berlin, Chair of Materials Science and Engineering, Institute of Materials Science and Technologies, Str. des 17. Juni 136 - Sekr. EB13, 10623 Berlin, Germany.
| | - Martin Burke
- Technische Universität Berlin, Chair of Materials Science and Engineering, Institute of Materials Science and Technologies, Str. des 17. Juni 136 - Sekr. EB13, 10623 Berlin, Germany; Charité - Universitätsmedizin Berlin, Department for Operative and Preventive Dentistry, Aßmannshauser Str. 4-6, 14297 Berlin, Germany
| | - Gregor Ganzosch
- Technische Universität Berlin, Institute of Mechanics, Chair of Continuum Mechanics and Materials Theory, Einsteinufer 5 - Sekr. MS2, 10587 Berlin, Germany
| | - Cecilia Müller
- Technische Universität Berlin, Chair of Materials Science and Engineering, Institute of Materials Science and Technologies, Str. des 17. Juni 136 - Sekr. EB13, 10623 Berlin, Germany
| | - John D Currey
- The University of York, Department of Biology, Wentworth Way, York YO10 5DD, United Kingdom
| | - Paul Zaslansky
- Charité - Universitätsmedizin Berlin, Department for Operative and Preventive Dentistry, Aßmannshauser Str. 4-6, 14297 Berlin, Germany.
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Hashmi A, Sodhi RN, Kishen A. Interfacial Characterization of Dentin Conditioned with Chitosan Hydroxyapatite Precursor Nanocomplexes Using Time-of-flight Secondary Ion Mass Spectrometry. J Endod 2019; 45:1513-1521. [DOI: 10.1016/j.joen.2019.08.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 08/13/2019] [Accepted: 08/24/2019] [Indexed: 10/25/2022]
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Piperidou M, Sodhi RNS, Kolosowski KP, Basrani BR. Effects of Final Irrigation with SmearOFF on the Surface of Dentin Using Surface Analytical Methods. J Endod 2018; 44:1714-1719. [PMID: 30266468 DOI: 10.1016/j.joen.2018.07.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 07/14/2018] [Accepted: 07/26/2018] [Indexed: 11/19/2022]
Abstract
INTRODUCTION SmearOFF (Vista Dental Products, Racine, WI) is an irrigation solution containing chlorhexidine (CHX), EDTA, and a surfactant. This study examined the chemical interaction of SmearOFF with sodium hypochlorite (NaOCl) on the dentin surface, specifically the formation of precipitate and/or parachloroanaline (PCA). METHODS Dentin blocks prepared from human maxillary molars were mounted in resin. Dentinal tubules were exposed in a perpendicular orientation using an ultracryomicrotome. The blocks were divided into 2 groups: the CHX group, irrigation with 6% NaOCl, 17% EDTA, 6% NaOCl, and 2% CHX, and the SmearOFF group, irrigation with 6% NaOCl and SmearOFF. The dentin surface was analyzed with time-of-flight secondary ion mass spectrometry and X-ray photoelectron spectroscopy to determine the formation of precipitate or/and PCA on the surface of dentin. RESULTS Precipitation with PCA and occlusion of the dentinal tubules were noted on the dentin surface in the CHX group. No precipitate and no PCA were detected on the surface of dentin in the SmearOFF group. CONCLUSIONS Interaction of SmearOFF with NaOCl on the dentin surface did not result in the formation of precipitate or PCA.
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Affiliation(s)
- Myrto Piperidou
- MSc Endodontic Program, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada
| | - Rana N S Sodhi
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Kamil P Kolosowski
- MSc Endodontic Program, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada
| | - Bettina R Basrani
- MSc Endodontic Program, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.
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Huang XQ, Camba J, Gu LS, Bergeron BE, Ricucci D, Pashley DH, Tay FR, Niu LN. Mechanism of bioactive molecular extraction from mineralized dentin by calcium hydroxide and tricalcium silicate cement. Dent Mater 2017; 34:317-330. [PMID: 29179973 DOI: 10.1016/j.dental.2017.11.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 10/10/2017] [Accepted: 11/10/2017] [Indexed: 02/07/2023]
Abstract
OBJECTIVES The objective of the present study was to elucidate the mechanism of bioactive molecule extraction from mineralized dentin by calcium hydroxide (Ca(OH)2) and tricalcium silicate cements (TSC). METHODS AND RESULTS Transmission electron microscopy was used to provide evidence for collagen degradation in dentin surfaces covered with Ca(OH)2 or a set, hydrated TSC for 1-3 months. A one micron thick collagen degradation zone was observed on the dentin surface. Fourier transform-infrared spectroscopy was used to identify increases in apatite/collagen ratio in dentin exposed to Ca(OH)2. Using three-point bending, dentin exposed to Ca(OH)2 exhibited significant reduction in flexural strength. Using size exclusion chromatography, it was found that the small size of the hydroxyl ions derived from Ca(OH)2 enabled those ions to infiltrate the intrafibrillar compartment of mineralized collagen and degrade the collagen fibrils without affecting the apatite minerals. Using ELISA, TGF-β1 was found to be extracted from dentin covered with Ca(OH)2 for 3 months. Unlike acids that dissolve the mineral component of dentin to release bioactive molecules, alkaline materials such as Ca(OH)2 or TSC released growth factors such as TGF-β1 via collagen degradation. SIGNIFICANCE The bioactive molecule extraction capacities of Ca(OH)2 and TSC render these dental materials excellent for pulp capping and endodontic regeneration. These highly desirable properties, however, appear to be intertwined with the untoward effect of degradation of the collagen matrix within mineralized dentin, resulting in reduced flexural strength.
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Affiliation(s)
- Xue-Qing Huang
- Department of Prosthodontics, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-Sen University, Guangzhou, Guangdong, PR China
| | - John Camba
- Department of Endodontics, The Dental College of Georgia, Augusta University, Augusta, GA, USA
| | - Li-Sha Gu
- Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, PR China
| | - Brian E Bergeron
- Department of Endodontics, The Dental College of Georgia, Augusta University, Augusta, GA, USA
| | | | - David H Pashley
- Department of Endodontics, The Dental College of Georgia, Augusta University, Augusta, GA, USA
| | - Franklin R Tay
- Department of Endodontics, The Dental College of Georgia, Augusta University, Augusta, GA, USA.
| | - Li-Na Niu
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Oral Diseases, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, PR China.
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Gu LS, Huang XQ, Griffin B, Bergeron BR, Pashley DH, Niu LN, Tay FR. Primum non nocere - The effects of sodium hypochlorite on dentin as used in endodontics. Acta Biomater 2017; 61:144-156. [PMID: 28801267 DOI: 10.1016/j.actbio.2017.08.008] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 07/28/2017] [Accepted: 08/07/2017] [Indexed: 10/19/2022]
Abstract
The medical literature is replete with the maxim 'primum non nocere', cautioning health care providers to avoid doing any harm to human subjects in their delivery of medical care. Sodium hypochlorite (NaOCl) is a well-established irrigant for root canal treatment because of its antimicrobial and organic tissue remnant dissolution capability. However, little is known about the deleterious effect of this strong oxidizing agent on the integrity of human mineralized dentin. Iatrogenically-induced loss of dentin integrity may precipitate post-treatment root fracture and has potential medico-legal complications. In the present work, transmission electron microscopy provided evidence for collagen destruction in the surface/subsurface of dentin treated with high NaOCl concentrations and long contact times. Size exclusion chromatography showed that the hypochlorite anion, because of its small size, penetrated the water compartments of apatite-encapsulated collagen fibrils, degraded the collagen molecules and produced a 25-35µm thick, non-uniform "ghost mineral layer" with enlarged, coalesced dentinal tubules and their lateral branches. Fourier transform-infrared spectroscopy identified increases in apatite/collagen ratio in NaOCl-treated dentin. The apatite-rich, collagen-sparse dentin matrix that remained after NaOCl treatment is more brittle, as shown by the reductions in flexural strength. Understanding the deleterious effects of NaOCl on mineralized dentin enables one to balance the risks and benefits in using high NaOCl concentrations for lengthy periods in root canal debridement. Delineating the mechanism responsible for such a phenomenon enables high molecular weight, polymeric antimicrobial and tissue dissolution irrigants to be designed that abides by the maxim of 'primum non nocere' in contemporary medical practices. STATEMENT OF SIGNIFICANCE The antimicrobial and tissue-dissolution capacities of NaOCl render it a well-accepted agent for root canal debridement. These highly desirable properties, however, appear to be intertwined with the untoward effect of collagen matrix degradation within mineralized dentin. Because of its small size, the hypochlorite anion is capable of infiltrating mineralized collagen and destroying the collagen fibrils, producing a mineral-rich, collagen sparse ghost mineral matrix with reduced flexural strength. Findings from the present work challenge the biosafety of NaOCl when it is used in high concentrations and for lengthy time periods during root canal treatment, and laid the background work for future biomaterials design in debridement of the canal space.
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Mashiko R, Inoue G, Nikaido T, Tagami J. Morphological evaluation of artificial caries-affected dentin after applying FCP-COMPLEX. J Oral Sci 2017; 59:343-350. [PMID: 28529278 DOI: 10.2334/josnusd.16-0312] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
FCP-COMPLEX is a newly-developed solution that contains fluoride, calcium, and phosphoric acid. It has the potential to reinforce caries-affected dentin. The purpose of this study was to evaluate the effect of FCP-COMPLEX on the morphology of bovine artificial caries-affected dentin (ACAD). FCP-COMPLEX, 2% sodium fluoride solution, and distilled water were applied to bovine ACAD and the effect on acid-induced damage was observed. Scanning electron microscopy was used to evaluate morphology after acid application. Energy dispersive X-ray spectroscopy was used for mapping and quantitative analyses of the dentin surface, and for line analysis of dentin-adhesive interface. The FCP-COMPLEX precipitated on the dentin surface and fluoride, calcium, and phosphorus were detected at a higher level in the FCP-COMPLEX group. The area of acid damage in caries-affected dentin was reduced by FCP-COMPLEX. In conclusion, FCP-COMPLEX significantly increased the deposition of fluoride onto bovine ACAD and inhibited demineralization.
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Affiliation(s)
- Ritsuko Mashiko
- Department of Cariology and Operative Dentistry, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
| | - Go Inoue
- Department of Cariology and Operative Dentistry, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
| | - Toru Nikaido
- Department of Cariology and Operative Dentistry, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
| | - Junji Tagami
- Department of Cariology and Operative Dentistry, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
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15
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Almhöjd US, Lingström P, Nilsson Å, Norén JG, Siljeström S, Östlund Å, Bernin D. Molecular Insights into Covalently Stained Carious Dentine Using Solid-State NMR and ToF-SIMS. Caries Res 2017; 51:255-263. [PMID: 28501859 DOI: 10.1159/000460828] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2016] [Accepted: 02/06/2017] [Indexed: 11/19/2022] Open
Abstract
Dyes currently used to stain carious dentine have a limited capacity to discriminate normal dentine from carious dentine, which may result in overexcavation. Consequently, finding a selective dye is still a challenge. However, there is evidence that hydrazine-based dyes, via covalent bonds to functional groups, bind specifically to carious dentine. The aim of this study was to investigate the possible formation of covalent bonds between carious dentine and 15N2-hydrazine and the hydrazine-based dye, 15N2-labelled Lucifer Yellow, respectively. Powdered dentine from extracted carious and normal teeth was exposed to the dyes, and the staining reactions were analysed using time-of-flight secondary ion mass spectrometry (ToF-SIMS), solid-state 13C-labelled nuclear magnetic resonance (NMR) and 15N-NMR spectroscopy. The results showed that 15N2-hydrazine and 15N2-labelled Lucifer Yellow both bind to carious dentine but not to normal dentine. It can thus be concluded that hydrazine-based dyes can be used to stain carious dentine and leave normal dentine unstained.
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Affiliation(s)
- Ulrica S Almhöjd
- Department of Cariology, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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16
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Rasi Ghaemi S, Delalat B, Cetó X, Harding FJ, Tuke J, Voelcker NH. Synergistic influence of collagen I and BMP 2 drives osteogenic differentiation of mesenchymal stem cells: A cell microarray analysis. Acta Biomater 2016. [PMID: 26196081 DOI: 10.1016/j.actbio.2015.07.027] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cell microarrays are a novel platform for the high throughput discovery of new biomaterials. By re-creating a multitude of cell microenvironments on a single slide, this approach can identify the optimal surface composition to drive a desired cell response. To systematically study the effects of molecular microenvironments on stem cell fate, we designed a cell microarray based on parallel exposure of mesenchymal stem cells (MSCs) to surface-immobilised collagen I (Coll I) and bone morphogenetic protein 2 (BMP 2). This was achieved by means of a reactive coating on a slide surface, enabling the covalent anchoring of Coll I and BMP 2 as microscale spots printed by a robotic contact printer. The surface between the printed protein spots was passivated using poly (ethylene glycol) bisamine 10,000Da (A-PEG). MSCs were then captured and cultured on array spots composed of binary mixtures of Coll I and BMP 2, followed by automated image acquisition and quantitative, multi-parameter analysis of cellular responses. Surface compositions that gave the highest osteogenic differentiation were determined using Runx2 expression and calcium deposition. Quantitative single cell analysis revealed subtle concentration-dependent effects of surface-immobilised proteins on the extent of osteogenic differentiation obscured using conventional analysis. In particular, the synergistic interaction of Coll I and BMP 2 in supporting osteogenic differentiation was confirmed. Our studies demonstrate the value of cell microarray platforms to decipher the combinatorial interactions at play in stem cell niche microenvironments.
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17
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Besinis A, van Noort R, Martin N. The use of acetone to enhance the infiltration of HA nanoparticles into a demineralized dentin collagen matrix. Dent Mater 2016; 32:385-93. [DOI: 10.1016/j.dental.2015.11.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 10/09/2015] [Accepted: 11/30/2015] [Indexed: 11/26/2022]
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18
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Dorvee JR, Gerkowicz L, Bahmanyar S, Deymier-Black A, Veis A. Chondroitin sulfate is involved in the hypercalcification of the organic matrix of bovine peritubular dentin. Arch Oral Biol 2016; 62:93-100. [PMID: 26656507 PMCID: PMC4806796 DOI: 10.1016/j.archoralbio.2015.11.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 08/25/2015] [Accepted: 11/09/2015] [Indexed: 10/22/2022]
Abstract
Apatitic mineral of dentin forms within the collagenous matrix (intertubular dentin, ITD) secreted from the odontoblastic processes (OP). Highly calcified mineral (peritubular dentin, PTD) is deposited at the interface between the ITD and each process membrane, creating a tubular system penetrating the dentin that extends from the dentino-enamel junction to the predentin-dentin junction. We focus on determining the composition of the PTD both with regard to its organic matrix and the inorganic phase. A laser capture technique has been adapted for the isolation of the mineralized PTD free from the ITD, and for the analysis of the PTD by SEM, TEM, and energy dispersive spectrometry (EDS), these data were subsequently compared with similar analyses of intact dentin slices containing ITD bounded-PTD annuli. Elemental line scans reveal clearly marked boundaries between ITD, PTD, and OP components, and illustrate the differences in composition, and topographical surface roughness. The organic matrix of the PTD was shown to be sulfur rich, and further antibody labeling showed the sulfated organic component to be chondroitin sulfate [corrected]. In this PTD organic matrix the S/Ca and Ca/P ratios were distinctly higher than in the ITD, indicating that polysaccharide bound S supplies the anionic counterion facilitating the formation of the apatitic PTD mineral.
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Affiliation(s)
- Jason R Dorvee
- Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Lauren Gerkowicz
- Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Sara Bahmanyar
- Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Alix Deymier-Black
- Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Arthur Veis
- Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA.
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19
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Kolosowski KP, Sodhi RN, Kishen A, Basrani BR. Qualitative Time-of-Flight Secondary Ion Mass Spectrometry Analysis of Root Dentin Irrigated with Sodium Hypochlorite, EDTA, or Chlorhexidine. J Endod 2015; 41:1672-7. [DOI: 10.1016/j.joen.2015.06.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2015] [Revised: 06/17/2015] [Accepted: 06/22/2015] [Indexed: 11/29/2022]
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20
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Contreras-Arriaga B, Rodríguez-Vilchis LE, Contreras-Bulnes R, Olea-Mejìa OF, Scougall-Vilchis RJ, Centeno-Pedraza C. Chemical and morphological changes in human dentin after Er:YAGlaser irradiation: EDS and SEM analysis. Microsc Res Tech 2015; 78:1019-25. [PMID: 26397964 DOI: 10.1002/jemt.22579] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 08/10/2015] [Accepted: 08/16/2015] [Indexed: 11/07/2022]
Abstract
Sixty samples of human dentin were divided into six groups (n = 10) and were irradiated with Er:YAG laser at 100 mJ-19.9 J/cm(2), 150 mJ-29.8 J/cm(2), 100 mJ-35.3 J/cm(2), 150 mJ-53.0 J/cm(2), 200 mJ-70.7 J/cm(2), and 250 mJ-88.5 J/cm(2), respectively, at 7 Hz under a water spray. The atomic percentages of carbon, oxygen, magnesium, calcium, and phosphorus and the Ca-to-P molar ratio on the dentin were determined by energy dispersive X-ray spectroscopy. The morphological changes were observed using scanning electron microscopy. A paired t-test was used in statistical analysis before and after irradiation, and a one-way ANOVA was performed (P ≤ 0.05). The atomic percent of C tended to decrease in all of the groups after irradiation with statistically significant differences, O and Mg increased with significant differences in all of the groups, and the Ca-to-P molar ratio increased in groups IV, V, and VI, with statistically significant differences between groups II and VI. All the irradiated samples showed morphological changes. Major changes in the chemical composition of dentin were observed in trace elements. A significant increase in the Ca-to-P ratio was observed in the higher energy density groups. Morphological changes included loss of smear layer with exposed dentinal tubules. The changes produced by the different energy densities employed could have clinical implications, additional studies are required to clarify them.
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Affiliation(s)
- Belinda Contreras-Arriaga
- Facultad de Odontología, Centro de Investigación y Estudios Avanzados en Odontología (CIEAO), Universidad Autónoma del Estado de México, Jesús Carranza Esq. Paseo Tollocan, Col. Universidad, Toluca, Estado de México, C.P. 50130, México
| | - Laura Emma Rodríguez-Vilchis
- Facultad de Odontología, Centro de Investigación y Estudios Avanzados en Odontología (CIEAO), Universidad Autónoma del Estado de México, Jesús Carranza Esq. Paseo Tollocan, Col. Universidad, Toluca, Estado de México, C.P. 50130, México
| | - Rosalía Contreras-Bulnes
- Facultad de Odontología, Centro de Investigación y Estudios Avanzados en Odontología (CIEAO), Universidad Autónoma del Estado de México, Jesús Carranza Esq. Paseo Tollocan, Col. Universidad, Toluca, Estado de México, C.P. 50130, México
| | - Oscar Fernando Olea-Mejìa
- Universidad Autónoma Del Estado de México-Universidad Nacional Autónoma de México, Centro Conjunto de Investigación en Química Sustentable (CCIQS), Km 14.5 Carretera Toluca-Ixtlahuaca, San Cayetano de Morelos, Toluca, Estado de México, C.P. 50200, México
| | - Rogelio José Scougall-Vilchis
- Facultad de Odontología, Centro de Investigación y Estudios Avanzados en Odontología (CIEAO), Universidad Autónoma del Estado de México, Jesús Carranza Esq. Paseo Tollocan, Col. Universidad, Toluca, Estado de México, C.P. 50130, México
| | - Claudia Centeno-Pedraza
- Facultad de Odontología, Centro de Investigación y Estudios Avanzados en Odontología (CIEAO), Universidad Autónoma del Estado de México, Jesús Carranza Esq. Paseo Tollocan, Col. Universidad, Toluca, Estado de México, C.P. 50130, México
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21
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Forien JB, Fleck C, Cloetens P, Duda G, Fratzl P, Zolotoyabko E, Zaslansky P. Compressive Residual Strains in Mineral Nanoparticles as a Possible Origin of Enhanced Crack Resistance in Human Tooth Dentin. NANO LETTERS 2015; 15:3729-3734. [PMID: 26009930 DOI: 10.1021/acs.nanolett.5b00143] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The tough bulk of dentin in teeth supports enamel, creating cutting and grinding biostructures with superior failure resistance that is not fully understood. Synchrotron-based diffraction methods, utilizing micro- and nanofocused X-ray beams, reveal that the nm-sized mineral particles aligned with collagen are precompressed and that the residual strains vanish upon mild annealing. We show the link between the mineral nanoparticles and known damage propagation trajectories in dentin, suggesting a previously overlooked compression-mediated toughening mechanism.
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Affiliation(s)
| | - Claudia Fleck
- ‡Materials Engineering, Berlin Institute of Technology, 10623 Berlin, Germany
| | - Peter Cloetens
- §European Synchrotron Radiation Facility, 38043 Grenoble, France
| | - Georg Duda
- †Julius Wolff Institute, Charité-Universitätsmedizin, 13353 Berlin, Germany
| | - Peter Fratzl
- ⊥Department of Biomaterials, Max-Planck-Institute of Colloids and Interfaces, 14424 Potsdam, Germany
| | - Emil Zolotoyabko
- ¶Department of Materials Science and Engineering, Technion-Israel Institute of Technology, 32000 Haifa, Israel
| | - Paul Zaslansky
- †Julius Wolff Institute, Charité-Universitätsmedizin, 13353 Berlin, Germany
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22
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Stock S, Deymier-Black A, Veis A, Telser A, Lux E, Cai Z. Bovine and equine peritubular and intertubular dentin. Acta Biomater 2014; 10:3969-77. [PMID: 24911530 DOI: 10.1016/j.actbio.2014.05.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 05/15/2014] [Accepted: 05/23/2014] [Indexed: 10/25/2022]
Abstract
Dentin contains 1-2μm diameter tubules extending from the pulp cavity to near the junction with enamel. Peritubular dentin (PTD) borders the tubule lumens and is surrounded by intertubular dentin (ITD). Differences in PTD and ITD composition and microstructure remain poorly understood. Here, a (∼200nm)(2), 10.1keV synchrotron X-ray beam maps X-ray fluorescence and X-ray diffraction simultaneously around tubules in 15-30μm thick bovine and equine specimens. Increased Ca fluorescence surrounding tubule lumens confirms that PTD is present, and the relative intensities in PTD and ITD correspond to carbonated apatite (cAp) volume fraction of ∼0.8 in PTD vs. 0.65 assumed for ITD. In the PTD near the lumen edges, Zn intensity is strongly peaked, corresponding to a Zn content of ∼0.9mgg(-1) for an assumed concentration of ∼0.4mgg(-1) for ITD. In the equine specimen, the Zn K-edge position indicates that Zn(2+) is present, similar to bovine dentin (Deymier-Black et al., 2013), and the above edge structure is consistent with spectra from macromolecules related to biomineralization. Transmission X-ray diffraction shows only cAp, and the 00.2 diffraction peak (Miller-Bravais indices) width is constant from ITD to the lumen edge. The cAp 00.2 average preferred orientation is axisymmetric (about the tubule axis) in both bovine and equine dentin, and the axisymmetric preferred orientation continues from ITD through the PTD to the tubule lumen. These data indicate that cAp structure does not vary from PTD to ITD.
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23
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Deymier-Black AC, Veis A, Cai Z, Stock SR. Crystallographic texture and elemental composition mapped in bovine root dentin at the 200 nm level. SCANNING 2014; 36:231-240. [PMID: 23630059 PMCID: PMC4727833 DOI: 10.1002/sca.21093] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Accepted: 03/18/2013] [Indexed: 06/02/2023]
Abstract
The relationship between the mineralization of peritubular dentin (PTD) and intertubular dentin (ITD) is not well understood. Tubules are quite small, diameter ∼2 µm, and this makes the near-tubule region of dentin difficult to study. Here, advanced characterization techniques are applied in a novel way to examine what organic or nanostructural signatures may indicate the end of ITD or the beginning of PTD mineralization. X-ray fluorescence intensity (Ca, P, and Zn) and X-ray diffraction patterns from carbonated apatite (cAp) were mapped around dentintubules at resolutions ten times smaller than the feature size (200 nm pixels), representing a 36% increase in resolution over earlier work. In the near tubule volumes of near-pulp, root dentin, Zn intensity was higher than in ITD remote from the tubules. This increase in Zn(2+), as determined by X-ray absorption near edge structure analysis, may indicate the presence of metalloenzymes or transcription factors important to ITD or PTD mineralization. The profiles of the cAp 00.2 X-ray diffraction rings were fitted with a pseudo-Voigt function, and the spatial and azimuthal distribution of these rings' integrated intensities indicated that the cAp platelets were arranged with their c-axes aligned tangential to the edge of the tubule lumen. This texture was continuous throughout the dentin indicating a lack of structural difference between in the Zn rich near-tubular region and the remote ITD.
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Affiliation(s)
- A. C. Deymier-Black
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois
| | - A. Veis
- Department of Cell and Molecular Biology, Northwestern University, Chicago, Illinois
| | - Z. Cai
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois
| | - S. R. Stock
- Department of Molecular Pharmacology and Biological Chemistry, Northwestern University, Chicago, Illinois
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24
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Zaslansky P, Maerten A, Fratzl P. Apatite alignment and orientation at the Ångstrom and nanometer length scales shed light on the adaptation of dentine to whole tooth mechanical function. BIOINSPIRED BIOMIMETIC AND NANOBIOMATERIALS 2013. [DOI: 10.1680/bbn.13.00007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Human teeth are capped by a highly mineralized enamel layer that rests on a bone-like material termed dentine. Dentine is composed mainly of collagen and carbonated apatite known to form the biological composite of all types of bone by combining into mineralized collagen fibrils. The apatite mineral is found both within and also encasing the fibrils, but in dentine, particularly in the crown, mineral is also found in regions where there is no collagen, forming peritubular dentine cuffs that surround narrow channels that perforate and render dentine porous. The authors hypothesize that regional variations in the mineral spatial configuration may reflect local adaptation to functional needs of whole teeth. The 3D orientation of the micron-sized tubules and the associated clusters of peritubular mineral vary on the length scale of millimeters. The orientation and degree of coalignment of the nanometer-sized mineral platelets in dentine exhibit marked changes at the same length scale, matching predicted load-trajectories in loaded teeth. However, wide-angle X-ray diffraction mapping shows that there is almost no preferred orientation of the 002 reflection (and hence the c-axis of apatite). The authors thus propose that the orientation of the peritubular and intertubular mineral compensate for localized preferred orientations, to create an overall average, randomly oriented mineral configuration.
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Affiliation(s)
- P. Zaslansky
- Julius Wolff Institute and Berlin-Brandenburg Center for Regenerative Therapies, CharitÉ – UniversitÄtsmedizin, Berlin, Germany
| | - A. Maerten
- Materials Engineering, Technische UniversitÄt, Berlin, Germany
| | - P. Fratzl
- Department of Biomaterials, Max-Planck-Institute of Colloids and Interfaces, Potsdam, Germany
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25
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Eltit F, Ebacher V, Wang R. Inelastic deformation and microcracking process in human dentin. J Struct Biol 2013; 183:141-8. [DOI: 10.1016/j.jsb.2013.04.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 03/16/2013] [Accepted: 04/01/2013] [Indexed: 11/28/2022]
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26
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Xue J, Zavgorodniy AV, Kennedy BJ, Swain MV, Li W. X-ray microdiffraction, TEM characterization and texture analysis of human dentin and enamel. J Microsc 2013; 251:144-53. [PMID: 23718843 DOI: 10.1111/jmi.12053] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Accepted: 04/23/2013] [Indexed: 02/05/2023]
Abstract
Human tooth is a complex bioceramic composite, which consists of enamel, dentin and the interface, the dentin-enamel junction (DEJ). The crystal properties and ultrastructure of the inorganic phase through the thickness of healthy human molar teeth were investigated using X-ray microdiffraction (μXRD), electron diffraction and transmission electron microscopy (TEM) techniques. The XRD data were analysed using the Le Bail profile fitting approach. The size and the texture of the crystallites forming enamel and dentin in the crown part of teeth were measured using both techniques and then compared. Results showed that the thickness of dentin crystallites was found to decrease towards the DEJ, whereas the thickness of the enamel crystallites increased from the DEJ towards the outer layers. It was demonstrated that enamel exhibited an increase of texture in 002 lattice planes from the DEJ towards the outer layers. Texture was also detected in 102 lattice planes. The texture effect in 002 planes at the scale of less than 1 μm was also demonstrated in dentin. The variation of lattice parameters as a function of the position within the thickness of dentin and enamel was also observed. The values of the nonuniform microstrain in the dentin and enamel crystallites were from 1.40 × 10(-6) % to 4.44 × 10(-5) %. The good correlation between XRD and TEM indicated that μXRD is a useful technique to study crystallography and microstructure of heterogeneous enamel and dentin. The observed gradient characteristics of texture and crystallite size in enamel and dentin maybe an evolutionary outcome to resist wear and fracture, thereby contributing to the excellent mechanical properties of teeth.
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Affiliation(s)
- J Xue
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China
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Charadram N, Austin C, Trimby P, Simonian M, Swain MV, Hunter N. Structural analysis of reactionary dentin formed in response to polymicrobial invasion. J Struct Biol 2013; 181:207-22. [PMID: 23261402 PMCID: PMC3578079 DOI: 10.1016/j.jsb.2012.12.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2012] [Revised: 12/06/2012] [Accepted: 12/08/2012] [Indexed: 11/23/2022]
Abstract
In response to microbial invasion of dentin odontoblasts secrete an altered calcified matrix termed reactionary dentin (Rd). 3D reconstruction of focused-ion-beam scanning electron microscopy (FIB-SEM) image slices revealed helical tubular structures in Rd that contrasted with regular cylindrical tubules characteristic of dentin from healthy teeth and affected so-called physiological dentin (Pd) lying exterior to Rd. This helical structure in Rd provided effective constriction of tubule lumen diameter that formed a barrier to bacterial advance towards the dental pulp. SEM of resin cast preparations revealed altered extension of odontoblast processes through Rd. The distribution of key mineral elements was studied by combination of 3D reconstruction of focused-ion-beam based X-ray microanalysis (FIB-EDS), laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). There was a marked redistribution of calcium and phosphorous in Rd together with an increase of diffusely deposited magnesium compatible with the mineral deposition phase of synthesis of this altered matrix. Changes in tubule structure and mineral content characteristic of Rd are consistent with reduced hardness and lower elastic modulus reported for this matrix. Findings provide insight into the unique structure of Rd synthesised as a primary response to infection.
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Affiliation(s)
- Nattida Charadram
- Institute of Dental Research, Westmead Millennium Institute and Westmead Centre for Oral Health, Westmead, Sydney, New South Wales, Australia
- Faculty of Dentistry, University of Sydney, Sydney, New South Wales, Australia
| | - Christine Austin
- Institute of Dental Research, Westmead Millennium Institute and Westmead Centre for Oral Health, Westmead, Sydney, New South Wales, Australia
- Elemental Bio-imaging Facility, Department of Chemistry and Forensic Science, University of Technology Sydney, New South Wales, Australia
| | - Patrick Trimby
- Australian Centre For Microscopy & Microanalysis, University of Sydney, Sydney, New South Wales, Australia
| | - Mary Simonian
- Institute of Dental Research, Westmead Millennium Institute and Westmead Centre for Oral Health, Westmead, Sydney, New South Wales, Australia
| | - Michael V. Swain
- Faculty of Dentistry, University of Sydney, Sydney, New South Wales, Australia
| | - Neil Hunter
- Institute of Dental Research, Westmead Millennium Institute and Westmead Centre for Oral Health, Westmead, Sydney, New South Wales, Australia
- Faculty of Dentistry, University of Sydney, Sydney, New South Wales, Australia
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Guimarães GN, Cardoso GBC, Naves LZ, Correr-Sobrinho L, Line SRP, Marques MR. Short-term PTH administration increases dentine apposition and microhardness in mice. Arch Oral Biol 2012; 57:1313-9. [DOI: 10.1016/j.archoralbio.2012.03.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Revised: 02/01/2012] [Accepted: 03/29/2012] [Indexed: 11/29/2022]
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29
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Tjäderhane L, Carrilho MR, Breschi L, Tay FR, Pashley DH. Dentin basic structure and composition-an overview. ACTA ACUST UNITED AC 2012. [DOI: 10.1111/j.1601-1546.2012.00269.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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30
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Tjäderhane L, Haapasalo M. The dentin-pulp border: a dynamic interface between hard and soft tissues. ACTA ACUST UNITED AC 2012. [DOI: 10.1111/j.1601-1546.2012.00266.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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31
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Srot V, Bussmann B, Salzberger U, Koch CT, van Aken PA. Linking microstructure and nanochemistry in human dental tissues. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2012; 18:509-523. [PMID: 22494533 DOI: 10.1017/s1431927612000116] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Mineralized dental tissues and dental pulp were characterized using advanced analytical transmission electron microscopy (TEM) methods. Quantitative X-ray energy dispersive spectroscopy was employed to determine the Ca/P and Mg/P concentration ratios. Significantly lower Ca/P concentration ratios were measured in peritubular dentine compared to intertubular dentine, which is accompanied by higher and variable Mg/P concentration ratios. There is strong evidence that magnesium is partially substituting calcium in the hydroxyapatite structure. Electron energy-loss near-edge structures (ELNES) of C-K and O-K from enamel and dentine are noticeably different. We observe a strong influence of beam damage on mineralized dental tissues and dental pulp, causing changes of the composition and consequently also differences in the ELNES. In this article, the importance of TEM sample preparation and specimen damage through electron irradiation is demonstrated.
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Affiliation(s)
- Vesna Srot
- Stuttgart Center for Electron Microscopy, Max Planck Institute for Intelligent Systems, Heisenbergstrasse 3, 70569 Stuttgart, Germany.
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32
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Mechanical heterogeneity of dentin at different length scales as determined by AFM phase contrast. Micron 2012; 43:1364-71. [PMID: 22575216 DOI: 10.1016/j.micron.2012.03.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2012] [Revised: 03/22/2012] [Accepted: 03/27/2012] [Indexed: 11/22/2022]
Abstract
In this study we sought to gain insights of the structural and mechanical heterogeneity of dentin at different length scales. We compared four distinct demineralization protocols with respect to their ability to expose the periodic pattern of dentin collagen. Additionally, we analyzed the phase contrast resulting from AFM images obtained in tapping mode to interrogate the viscoelastic behavior and surface adhesion properties of peritubular and intertubular dentin, and partially demineralized dentin collagen fibrils, particularly with respect to their gap and overlap regions. Results demonstrated that all demineralization protocols exposed the gap and overlap zones of dentin collagen fibrils. Phase contrast analyses suggested that the intertubular dentin, where the organic matrix is concentrated, generated a higher phase contrast due a higher contribution of energy dissipation (damping) than the highly mineralized peritubular region. At increasing amplitudes, viscoelasticity appeared to play a more significant contribution to the phase contrast of the images of collagen fibrils. The overlap region yielded a greater phase contrast than the more elastic gap zones. In summary, our results contribute to the perspective that, at different length scales, dentin is constituted of structural features that retain heterogeneous mechanical properties contributing to overall mechanical performance of the tissue. Furthermore, the interpretation of phase contrast from images generated with AFM tapping mode appears to be an effective tool to gain an improved understanding of the structure and property relationship of biological tissues and biomaterials at the micro- and nano-scale.
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33
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Farahani RM, Simonian M, Hunter N. Blueprint of an ancestral neurosensory organ revealed in glial networks in human dental pulp. J Comp Neurol 2011; 519:3306-26. [DOI: 10.1002/cne.22701] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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34
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Bertassoni LE, Stankoska K, Swain MV. Insights into the structure and composition of the peritubular dentin organic matrix and the lamina limitans. Micron 2011; 43:229-36. [PMID: 21890367 DOI: 10.1016/j.micron.2011.08.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 06/17/2011] [Accepted: 08/08/2011] [Indexed: 10/17/2022]
Abstract
Dentin is a mineralized dental tissue underlying the outer enamel that has a peculiar micro morphology. It is composed of micrometer sized tubules that are surrounded by a highly mineralized structure, called peritubular dentin (PTD), and embedded in a collagen-rich matrix, named intertubular dentin. The PTD has been thought to be composed of a highly mineralized collagen-free organic matrix with unknown composition. Here we tested the hypothesis that proteoglycans and glycosaminoglycans, two important organic structural features found in dentin, are key participants in the microstructure and composition of the PTD. To test this hypothesis dentin blocks were demineralized with 10 vol% citric acid for 2 min and either digested with 1mg/ml TPCK-treated trypsin with 0.2 ammonium bicarbonate at pH 7.9 (TRY) or 0.1 U/mL C-ABC with 50mM Tris, 60mM sodium acetate and 0.02% bovine serum albumin at pH 8.0 (C-ABC). TRY is known to cleave the protein core of dentin proteoglycans, whereas C-ABC is expected to selectively remove glycosaminoglycans. All specimens were digested for 48 h in 37°C, dehydrated in ascending grades of acetone, immersed in HMDS, platinum coated and imaged using an FE-SEM. Images of demineralized dentin revealed a meshwork of noncollagenous fibrils protruding towards the tubule lumen following removal of the peritubular mineral and confirmed the lack of collagen in the peritubular matrix. Further, images revealed that the peritubular organic network originates from a sheet-like membrane covering the entire visible length of tubule, called lamina limitans. Confirming our initial hypothesis, after the digestion with C-ABC the organic network appeared to vanish, while the lamina limitans was preserved. This suggests that glycosaminoglycans are the main component of the PTD organic network. Following digestion with TRY, both the organic network and the lamina limitans disappeared, thus suggesting that the lamina limitans may be primarily composed of proteoglycan protein cores. In summary, our results provide novel evidence that (1) PTD lacks collagen fibrils, (2) PTD contains an organic scaffold embedded with mineral and (3) the PTD organic matrix is manly composed of glycosaminoglycans, whereas the lamina limitans is primarily made of proteoglycans protein cores.
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Affiliation(s)
- Luiz Eduardo Bertassoni
- Biomaterials Research Unit, Faculty of Dentistry, University of Sydney, Sydney Dental Hospital, 2 Chalmers Street, Surry Hills, NSW 2010, Australia.
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Stock SR, Veis A, Telser A, Cai Z. Near tubule and intertubular bovine dentin mapped at the 250 nm level. J Struct Biol 2011; 176:203-11. [PMID: 21821132 DOI: 10.1016/j.jsb.2011.07.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Revised: 07/21/2011] [Accepted: 07/23/2011] [Indexed: 11/29/2022]
Abstract
In this study, simultaneous diffraction and fluorescence mapping with a (250nm)(2), 10.1keV synchrotron X-ray beam investigated the spatial distribution of carbonated apatite (cAp) mineral and elemental Ca (and other cations including Zn) around dentin tubules. In 1μm thick sections of near-pulp root dentin, where peritubular dentin (PTD) is newly forming, high concentrations of Zn, relative to those in intertubular dentin (ITD), were observed adjacent to and surrounding the tubule lumens. Some but not all tubules exhibited hypercalcified collars (high Ca signal relative to the surrounding ITD), and, when present, the zone of high Ca did not extend around the tubule. Diffraction rings from cAp 00.2 and 11.2+21.1+30.0 reflections were observed, and cAp was the only crystal phase detected. Profiles of Ca, Zn and cAp diffracted intensities showed the same transitions from solid to tubule lumen, indicating the same cAp content and organization in ITD far from the tubules and adjacent to them. Further, the matching Ca and diffraction profiles demonstrated that all of the Ca is in cAp or that any noncrystalline Ca was uniformly distributed throughout the dentin. Variation of 00.2 and 11.2+21.1+30.0 diffracted intensity was consistent with the expected biaxial crystallographic texture. Extension of X-ray mapping from near 1μm resolution to the 250nm level, performed here for dentin and its tubules, will provide new understanding of other mineralized tissues.
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Affiliation(s)
- S R Stock
- Department of Molecular Pharmacology and Biological Chemistry, Feinberg School of Medicine, Northwestern University, Mail Code S215, 303 E. Chicago Ave., Chicago, IL 60611-3008, USA.
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Farre B, Brunelle A, Laprévote O, Cuif JP, Williams CT, Dauphin Y. Shell layers of the black-lip pearl oyster Pinctada margaritifera: Matching microstructure and composition. Comp Biochem Physiol B Biochem Mol Biol 2011; 159:131-9. [DOI: 10.1016/j.cbpb.2011.03.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2011] [Revised: 03/03/2011] [Accepted: 03/07/2011] [Indexed: 10/18/2022]
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37
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Kalthoff DC. Microstructure of dental hard tissues in fossil and recent xenarthrans (Mammalia: Folivora and Cingulata). J Morphol 2011; 272:641-61. [DOI: 10.1002/jmor.10937] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Revised: 11/03/2010] [Accepted: 11/05/2010] [Indexed: 11/11/2022]
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38
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Goldberg M, Kulkarni AB, Young M, Boskey A. Dentin: structure, composition and mineralization. Front Biosci (Elite Ed) 2011; 3:711-35. [PMID: 21196346 DOI: 10.2741/e281] [Citation(s) in RCA: 391] [Impact Index Per Article: 30.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We review firstly the specificities of the different types of dentin present in mammalian teeth. The outer layers include the mantle dentin, the Tomes' granular and the hyaline Hopewell-Smith's layers. Circumpulpal dentin forming the bulk of the tooth, comprises intertubular and peritubular dentin. In addition to physiological primary and secondary dentin formation, reactionary dentin is produced in response to pathological events. Secondly, we evaluate the role of odontoblasts in dentin formation, their implication in the synthesis and secretion of type I collagen fibrils and non-collagenous molecules. Thirdly, we study the composition and functions of dentin extracellular matrix (ECM) molecules implicated in dentinogenesis. As structural proteins they are mineralization promoters or inhibitors. They are also signaling molecules. Three different forms of dentinogenesis are identified: i) matrix vesicles are implicated in early dentin formation, ii) collagen and some proteoglycans are involved in the formation of predentin, further transformed into intertubular dentin, iii) the distal secretion of some non-collagenous ECM molecules and some serum proteins contribute to the formation of peritubular dentin.
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Affiliation(s)
- Michel Goldberg
- UMR-S 747, INSERM, Universite Paris Descartes, Paris, France.
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Beniash E, Deshpande AS, Fang PA, Lieb NS, Zhang X, Sfeir CS. Possible role of DMP1 in dentin mineralization. J Struct Biol 2010; 174:100-6. [PMID: 21081166 DOI: 10.1016/j.jsb.2010.11.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 11/05/2010] [Accepted: 11/09/2010] [Indexed: 02/05/2023]
Abstract
Dentin Matrix Protein 1 (DMP1), the essential noncollagenous proteins in dentin and bone, is believed to play an important role in the mineralization of these tissues, although the mechanisms of its action are not fully understood. To gain insight into DMP1 functions in dentin mineralization we have performed immunomapping of DMP1 in fully mineralized rat incisors and in vitro calcium phosphate mineralization experiments in the presence of DMP1. DMP1 immunofluorescene was localized in peritubular dentin (PTD) and along the dentin-enamel boundary. In vitro phosphorylated DMP1 induced the formation of parallel arrays of crystallites with their c-axes co-aligned. Such crystalline arrangement is a hallmark of mineralized collagen fibrils of bone and dentin. Interestingly, in DMP1-rich PTD, which lacks collagen fibrils, the crystals are organized in a similar manner. Based on our findings we hypothesize, that in vivo DMP1 controls the mineral organization outside of the collagen fibrils and plays a major role in the mineralization of PTD.
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Affiliation(s)
- Elia Beniash
- Department of Oral Biology, Center for Craniofacial Regeneration, University of Pittsburgh, School of Dental Medicine, Pittsburgh, PA, USA
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40
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Märten A, Fratzl P, Paris O, Zaslansky P. On the mineral in collagen of human crown dentine. Biomaterials 2010; 31:5479-90. [DOI: 10.1016/j.biomaterials.2010.03.030] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2009] [Accepted: 03/15/2010] [Indexed: 11/30/2022]
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41
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Mai S, Kim YK, Arola DD, Gu LS, Kim JR, Pashley DH, Tay FR. Differential aggressiveness of ethylenediamine tetraacetic acid in causing canal wall erosion in the presence of sodium hypochlorite. J Dent 2010; 38:201-6. [DOI: 10.1016/j.jdent.2009.10.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Revised: 10/13/2009] [Accepted: 10/13/2009] [Indexed: 11/30/2022] Open
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42
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Xu Z, Neoh KG, Amaechi B, Kishen A. Monitoring bacterial-demineralization of human dentine by electrochemical impedance spectroscopy. J Dent 2009; 38:138-48. [PMID: 19804810 DOI: 10.1016/j.jdent.2009.09.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2009] [Revised: 09/21/2009] [Accepted: 09/27/2009] [Indexed: 12/16/2022] Open
Abstract
OBJECTIVE The purpose of this study was two-fold: (1) to monitor bacterial biofilm formation and bacteria-induced demineralization of dentine in situ by using electrochemical impedance spectrum (EIS); (2) to examine the relationship between EIS findings and changes in the chemical composition and ultrastructure of dentine during bacteria-induced demineralization. METHODS In this study, dentine demineralization was induced by Streptococcusmutans (ATCC 25175) in the presence of sucrose in culture medium and was monitored using two EIS measurement systems (Type A with a working electrode and Type B without a working electrode). Scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD) were employed to examine the morphology, element contents and crystallinity of hydroxyapatite (HAP) on the dentine surface. Transverse microradiography (TMR) was used to characterize the lesion depth and degree of mineral loss during demineralization. RESULTS The resistance of the bulk dentine (R(d)) and the apparent resistance of dentine (R(a)) measured from the Type A and Type B EIS systems, respectively, decreased gradually with demineralization. The resistance of the biofilm formed on dentine surface was determined by fitting the EIS data with equivalent circuits. The presence of biofilm slightly increased R(a) of dentine before demineralization. However, the electrochemical behavior of biofilm did not affect the decreasing impedance of dentine with demineralization. The SEM, EDX, XRD and TMR results demonstrated that the surface and bulk dentine gradually became more porous due to the loss of minerals during demineralization, which in turn resulted in the decrease in R(d) and R(a) values obtained from EIS systems. CONCLUSIONS This investigation highlighted EIS as a potential technique to monitor biofilm formation and bacterial-induced demineralization in situ.
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Affiliation(s)
- Zhang Xu
- Department of Restorative Dentistry, Faculty of Dentistry, National University of Singapore, 5 Lower Kent Ridge Road, 119074 Singapore, Singapore
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Synthesis and intracellular transportation of type I procollagen during functional differentiation of odontoblasts. Histochem Cell Biol 2009; 131:583-91. [DOI: 10.1007/s00418-009-0556-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/03/2009] [Indexed: 11/26/2022]
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44
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Monitoring acid-demineralization of human dentine by electrochemical impedance spectroscopy (EIS). J Dent 2008; 36:1005-12. [DOI: 10.1016/j.jdent.2008.08.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2008] [Revised: 08/13/2008] [Accepted: 08/16/2008] [Indexed: 11/19/2022] Open
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45
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Malmberg P, Nygren H. Methods for the analysis of the composition of bone tissue, with a focus on imaging mass spectrometry (TOF-SIMS). Proteomics 2008; 8:3755-62. [DOI: 10.1002/pmic.200800198] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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46
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Abstract
Many genes critical to vertebrate skeletal mineralization are members of the secretory calcium-binding phosphoprotein (SCPP) gene family, which has evolved by gene duplication from a single ancestral gene. In humans, mutations in some of these SCPP genes have been associated with various diseases related to dentin or enamel hypoplasia. Recently, systematic searches for SCPP genes of various species have allowed us to investigate the history of phylogenetically variable dental tissues as a whole. One important conclusion is that not all disease-associated SCPP genes are present in tetrapods, and teleost fish probably have none, even in toothed species, having acquired their complement of SCPP genes through an independent duplication history. Here, we review comparative analyses of mineralized dental tissues, with particular emphasis on the use of SCPPs, within and between tetrapods and teleosts. Current knowledge suggests a close relationship among bone, dentin, teleost fish enameloid (enamel-like hard tissue), and tetrapod enamel. These tissues thus form a mineralized-tissue continuum. Contemporary dental tissues have evolved from an ancestral continuum through lineage-specific modifications.
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Affiliation(s)
- K Kawasaki
- Department of Anthropology, Pennsylvania State University, University Park, PA 16802, USA
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