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1.
J Endod ; 42(3): 418-24, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26794343

ABSTRACT

INTRODUCTION: The ferret canine tooth has been introduced as a suitable model for studying dental pulp regeneration. The aim of this study was to isolate and characterize ferret dental pulp stem cells (fDPSCs) and their differentiation potential. METHODS: Dental pulp stem cells were isolated from freshly extracted ferret canine teeth. The cells were examined for the expression of stem cell markers STRO-1, CD90, CD105, and CD146. The osteo/odontogenic and adipogenic differentiation potential of fDPSCs was evaluated. Osteogenic and odontogenic marker genes were evaluated using quantitative real-time polymerase chain reaction (qRT-PCR) on days 1, 4, and 8 after osteo/odontogenic induction of fDPSCs including dentin sialophosphoprotein (DSPP), dentin matrix protein-1, osteopontin, and alkaline phosphatase. Human dental pulp cells were used as the control. The results were analyzed using 3-way analysis of variance. RESULTS: fDPSCs were positive for STRO1, CD90, and CD105 and negative for CD146 markers with immunohistochemistry. fDPSCs showed strong osteogenic and weak adipogenic potential. The overall expression of DSPP was not significantly different between fDPSCs and human dental pulp cells. The expression of DSPP in osteo/odontogenic media was significantly higher in fDPSCs on day 4 (P < .01). The overall expression of dentin matrix protein-1, osteopontin, and alkaline phosphatase was significantly higher in fDPSCs (P = .0005). CONCLUSIONS: fDPSCs were positive for several markers of dental pulp stem cells resembling human DPSCs and appeared to show a stronger potential to differentiate to osteoblastic rather than odontoblastic lineage.


Subject(s)
Dental Pulp/cytology , Ferrets , Stem Cells/cytology , Animals , Antigens, CD/biosynthesis , Biomarkers/metabolism , Cattle , Cell Differentiation/physiology , Cells, Cultured , Cuspid/cytology , Cuspid/metabolism , Dental Pulp/metabolism , Female , Humans , Male , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/metabolism , Models, Animal , Odontoblasts/cytology , Odontogenesis/genetics , Osteogenesis/genetics , Stem Cells/metabolism
2.
J Endod ; 42(3): 397-401, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26778266

ABSTRACT

INTRODUCTION: This study was designed to evaluate the usefulness of magnetic resonance imaging (MRI) to assess the regeneration of pulp tissue. METHODS: Mobilized dental pulp stem cells and granulocyte colony-stimulating factor with collagen were transplanted into mature pulpectomized teeth for pulp regeneration (n = 4). The controls consisted of pulpectomized teeth with or without collagen and normal teeth with intact pulp tissue (n = 4, each). The signal intensity (SI) of MRI using T2 sequences was compared after the extraction of teeth in dogs. MRI was correlated with the corresponding histologic findings. RESULTS: Pulp tissue was fully regenerated 90 days after cell transplantation. On the other hand, the root canal was empty in the control collagen-transplanted teeth at 90 days. The SI of the normal teeth was significantly higher than that of nonvital pulpectomized teeth and the controls of collagen transplanted teeth at 90 days. The stem cell transplanted teeth showed a gradual decrease in the SI until 180 days at which time the SI was similar to that in the normal teeth and significantly higher than that in the teeth transplanted with collagen alone without the stem cells. CONCLUSIONS: The changes in the SI of the pulplike tissue were consistent with the histologic findings, showing the potential usefulness of the noninvasive method to serially access the efficacy of pulp regenerative therapy.


Subject(s)
Dental Pulp/physiology , Magnetic Resonance Imaging/methods , Regeneration/physiology , Stem Cell Transplantation/methods , Stem Cells/physiology , Animals , Cell Differentiation/drug effects , Cell Differentiation/physiology , Cuspid/cytology , Cuspid/drug effects , Cuspid/growth & development , Dental Pulp/cytology , Dental Pulp/drug effects , Dental Pulp Cavity/anatomy & histology , Dental Pulp Cavity/cytology , Dogs , Granulocyte Colony-Stimulating Factor/pharmacology , Models, Animal , Random Allocation , Regeneration/drug effects , Stem Cells/cytology
3.
Arch Oral Biol ; 60(10): 1533-44, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26276267

ABSTRACT

AIMS: To analyze expression patterns of IGF-1, caspase-3 and HSP-70 in human incisor and canine tooth germs during the late bud, cap and bell stages of odontogenesis. MATERIALS AND METHODS: Head areas or parts of jaw containing teeth from 10 human fetuses aged between 9th and 20th developmental weeks were immunohistochemically analyzed using IGF-1, active caspase-3 and HSP-70 markers. Semi-quantitative analysis of each marker's expression pattern was also performed. RESULTS: During the analyzed period, IGF-1 and HSP-70 were mostly expressed in enamel organ. As development progressed, expression of IGF-1 and HSP-70 became more confined to differentiating tissues in the future cusp tip area, as well as in highly proliferating cervical loops. Few apoptotic bodies highly positive to active caspase-3 were observed in enamel organ and dental papilla from the cap stage onward. However, both enamel epithelia moderately expressed active caspase-3 throughout the investigated period. CONCLUSIONS: Expression patterns of IGF-1, active caspase-3 and HSP-70 imply importance of these factors for early human tooth development. IGF-1 and HSP-70 have versatile functions in control of proliferation, differentiation and anti-apoptotic protection of epithelial parts of human enamel organ. Active caspase-3 is partially involved in formation and apoptotic removal of primary enamel knot, although present findings might reflect its ability to perform other non-death functions such as differentiation of hard dental tissues secreting cells and guidance of ingrowth of proliferating cervical loops.


Subject(s)
Caspase 3/biosynthesis , HSP70 Heat-Shock Proteins/biosynthesis , Insulin-Like Growth Factor I/biosynthesis , Tooth Germ/metabolism , Cell Differentiation , Cuspid/cytology , Cuspid/embryology , Cuspid/metabolism , Dental Enamel/metabolism , Dental Papilla/cytology , Dental Papilla/embryology , Dental Papilla/growth & development , Dental Papilla/metabolism , Enamel Organ/cytology , Enamel Organ/embryology , Enamel Organ/metabolism , Fetus , Humans , Immunohistochemistry , Incisor/embryology , Incisor/metabolism , Odontogenesis , Tooth Germ/cytology , Tooth Germ/embryology
4.
Bull Exp Biol Med ; 158(6): 824-6, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25894786

ABSTRACT

We examined morphometric parameters of the bone tissue of 168 dentoalveolar segments that include maxillary incisors and canines regarding vertical midline. The area of dentoalveolar medial incisor segments was 1.81±0.14 cm(2); it did not differ significantly from the area of lateral incisor segments. The area of dentoalveolar segments including canines exceeded the corresponding figures in incisor segments. The thickness of the compact bone on the vestibular surface significantly increased from the cervical portion of the segment towards its base. The maximum thickness of the spongy bone on the vestibular surface was recorded in the apical part of canines dentition segments; the minimum thickness, in the middle portion of the dentoalveolar segments of lateral incisors.


Subject(s)
Cuspid/anatomy & histology , Incisor/anatomy & histology , Cuspid/cytology , Female , Humans , Incisor/cytology , Male
5.
BMC Biotechnol ; 15: 114, 2015 Dec 30.
Article in English | MEDLINE | ID: mdl-26718927

ABSTRACT

BACKGROUND: We aimed to demonstrate that DF stem cells from impacted molars and canines can be used to improve bone regeneration on titanium implants surfaces. This study highlights the presence of stem cells in DF, their potential to adhere and differentiate into osteoblasts on different types of titanium surfaces. RESULTS: Isolated cells from the harvested DF tissue from impacted canine/molars, expressed stem cells markers. Differentiation into bone cells was induced in presence or absence of BMP-2 and TGFß1. The presence of growth factors until 28 days in medium maintained the cells in an earlier stage of differentiation with a lower level of specific bone proteins and a higher expression of alkaline phosphatase (ALP). Influence of titanium implants with different bioactive coatings, hydroxyapatite (TiHA) and with silicatitanate (TiSiO2), and porous Ti6Al7Nb implants as control (TiCtrl), was studied in terms of cell adhesion and viability. Ti HA implants proved to be more favorable for adhesion and proliferation of DF stem cells in first days of cultivation. The influence of titanium coatings and osteogenic differentiation mediums with or without growth factors were evaluated. Additional BMP-2 in the medium did not allow DF stem cells to develop a more mature phenotype, leaving them in a pre-osteogenic stage. The best sustained mineralization process evaluated by immuno-cytochemical staining, scanning electron microscopy and Ca(2+) quantification was observed for TiHA implants with a higher expression of ALP, collagen and Ca(2+) deposition. Long term culturing (70 days) on titanium surfaces of DF stem cells in standard medium without soluble osteogenic inducers, indicated that HA coating is more favorable, with the acquisition of a more mature osteoblastic phenotype as shown by immunocytochemical staining. These findings demonstrated that even in absence of exogenous osteogenic factors, TiHA implants and in a lesser extent TiCtrl and TiSiO2 implants can induce and sustain osteogenic differentiation of DF stem cells, by their chemical and topographical properties. CONCLUSIONS: Our research demonstrated that DF stem cells have a spontaneous tendency for osteogenic differentiation and can be used for improving bone regeneration on titanium implants surfaces.


Subject(s)
Bone Regeneration/physiology , Dental Implants , Dental Sac/cytology , Stem Cells/cytology , Titanium , Adolescent , Adult , Alkaline Phosphatase/metabolism , Cell Differentiation/physiology , Cells, Cultured , Coated Materials, Biocompatible/chemistry , Coated Materials, Biocompatible/metabolism , Cuspid/cytology , Durapatite/chemistry , Female , Humans , Mesenchymal Stem Cells/cytology , Molar/cytology , Osteoblasts/cytology , Osteoblasts/physiology , Osteogenesis , Young Adult
6.
Arch Histol Cytol ; 71(5): 317-32, 2008 Dec.
Article in English | MEDLINE | ID: mdl-19556693

ABSTRACT

Continuously growing rodent incisors have a special epithelial structure for maintaining adult stem cells that shows a bulbous epithelial protrusion at the apical end and is referred to as an "apical bud". Guinea pig cheek teeth (premolars and molars), also continuously growing teeth, have a complex crown shape consisting of plural cusps. The present study clarifies the existence of apical buds in guinea pig premolars/molars as it examines the relationship between the crown shape and the orientation of the apical buds by micro-computed tomography (micro-CT) and immunohistochemistry for 5-bromo-2'-deoxyuridine (BrdU). One premolar and three molar teeth in each side of the maxillae and mandibles assumed characteristic features: each horizontally-sectioned tooth showing a complex zigzag shape was composed of a core of dentin covered by a layer of enamel on all axial surfaces except the buccal of the uppers and the lingual of the lowers. Furthermore, four bulbous epithelial protrusions--including the stellate reticulum--were recognized in the apical end of each tooth, where slow-cycling long-term label-retaining cells resided 20 days after a peritoneal injection of BrdU. These data indicate that guinea pig premolars/molars have four apical buds where the epithelial adult stem cells reside. In contrast, rodent incisors, which show a single cone appearance, are covered by enamel on the labial side and possess only one apical bud. The results of this study suggest that plural apical buds, being arranged bucco-lingually and mesio-distally, produce the crown mold in a zigzag fashion.


Subject(s)
Bromodeoxyuridine/metabolism , Cheek/anatomy & histology , Cuspid/cytology , Staining and Labeling , Stem Cells/cytology , Animals , Cuspid/anatomy & histology , Cuspid/diagnostic imaging , Cuspid/growth & development , Epithelial Cells/cytology , Guinea Pigs , Kinetics , X-Ray Microtomography , X-Rays
7.
J Mol Histol ; 39(1): 87-94, 2008 Feb.
Article in English | MEDLINE | ID: mdl-17786571

ABSTRACT

The present study was designed to investigate the direct role of Shh molecule on cytodifferentiation and cusp formation. Affi-gel blue beads soaked in exogenous Shh-N, Shh antibody or BSA control protein were implanted between the epithelium and mesenchyme of isolated molar germs at the cap stage. The recombinants were grafted for culture under the kidney capsules respectively. In compared to the control, additional Shh-N protein could not enhance the ameloblasts and odontoblasts differentiation of the explanted tooth germs. While, application of Shh antibody retarded these events. After 4 weeks of subrenal culture, the teeth dissected from the explants treated with Shh-N were multicuspid. Most of the teeth harvested from the Shh antibody group were small and single irregularly shaped cusp was visible. The main cusp height in this group was reduced. The results indicated Shh signaling pathway is critical for odontoblast and ameloblast differentiation and patterns cusp formation.


Subject(s)
Cell Differentiation , Hedgehog Proteins/metabolism , Molar/cytology , Molar/embryology , Signal Transduction , Animals , Cells, Cultured , Cuspid/cytology , Dental Enamel/cytology , Dental Enamel/metabolism , Dentin/cytology , Dentin/metabolism , Gene Expression Regulation , Mice , Odontoblasts/cytology , Odontoblasts/metabolism , Patched Receptors , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptors, Cell Surface/genetics , Receptors, Cell Surface/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Time Factors
8.
Pediatr Dent ; 29(6): 475-9, 2007.
Article in English | MEDLINE | ID: mdl-18254417

ABSTRACT

PURPOSE: The purpose of this study was to evaluate histologically the effect of an enamel matrix derivative as a pulpotomy agent in primary canines. METHODS: Ten carious primary canines among teeth deemed for serial extraction were selected for this study. Emdogain gel was used as the pulp dressing material on the amputated pulp stumps. Teeth were extracted postoperatively after: (1) 1 week; (2) 2 weeks; and (3) 6 months. The extracted teeth were examined histologically to assess the response of the pulp to Emdogain gel after the pulpotomy procedure. RESULTS: Of the teeth extracted after 1 week, the amputated pulpal surface was lined by a thin, nearly continuous cellular layer. Generalized congestion was accompanied by an increase in angiogenesis. Of the teeth extracted after 2 weeks, most showed small islands of dentin-like tissue at different stages of mineralization. Of the teeth extracted after 6 months, several different histological pictures were viewed. Most of the teeth showed coalescing islands of dentin-like tissue trying to bridge the full width of the coronal pulp at the interface between the wounded and unharmed pulp tissue below the amputation site. CONCLUSION: Based on these experiments, Emdogain gel shows promising results as a valuable material for use in pulpotomy procedures, especially in the primary dentition.


Subject(s)
Cuspid/cytology , Dental Enamel Proteins/therapeutic use , Dental Pulp Capping/methods , Dental Pulp/drug effects , Pulpotomy/methods , Tooth, Deciduous/cytology , Amelogenin/therapeutic use , Child, Preschool , Cuspid/surgery , Dental Pulp/cytology , Dental Pulp Cavity/cytology , Dental Pulp Cavity/drug effects , Dental Pulp Cavity/surgery , Dentin/drug effects , Follow-Up Studies , Humans , In Vitro Techniques , Tooth, Deciduous/surgery
9.
Anat Rec ; 252(3): 462-71, 1998 11.
Article in English | MEDLINE | ID: mdl-9811224

ABSTRACT

Osteoclasts and odontoclasts are known to increase their nuclear number by fusion of mononuclear precursors. However, the pattern of fusion remains morphologically unclear. One lower right deciduous canine of an 8-year-old male was investigated. Tartrate-resistant acid phosphatase activity (TRAP) positive cells on the resorbing surface of the tooth were serially sectioned into 0.5 microm-thick semithin sections. The sections were photographed, and cells possessing a light microscopic brush border facing a resorptive lacuna were identified as odontoclasts. Fourteen odontoclasts appearing as a continuous figure of cellular membrane between cells on one section were three-dimensionally reconstructed using NIKON COSMOZONE 2SA. A criterion for fusion was established in this study, requiring that there must be two or more nucleated cells which contacted each other at one site only in the three-dimensional reconstruction. Among 14 reconstructed cells, 10 odontoclasts satisfied the criterion for fusion. The observations of the three-dimensional structures of these odontoclasts showed that mononuclear and multinucleated odontoclasts participated in fusion. Cell fusion occurred between resorbing odontoclasts and cells not forming lacunae, and between resorbing odontoclasts. A case of odontoclastic fusion among three cells was also observed. The results establish that fusion resulting in multinucleation occurred among various odontoclasts with different numbers of nuclei including mononuclear odontoclasts.


Subject(s)
Cell Fusion/physiology , Cell Nucleus/physiology , Cuspid/cytology , Image Processing, Computer-Assisted , Osteoclasts/cytology , Child , Humans , Male , Microtomy , Osteoclasts/ultrastructure
10.
Periodontia ; 2(4): 93-9, nov.-dez. 1993. ilus, tab
Article in Portuguese | BBO - Dentistry | ID: biblio-853534

ABSTRACT

O objetivo do presente estudo foi avaliar clínica, biométrica e histologicamente a eficácia do controle de placa supragengival na reparação do retalho reposicionado lateralmente. 5 cães adultos foram utilizados. Defeitos foram criados cirurgicamente na superfície bucal dos dentes caninos na maxila. Um retalho parcial foi mobilizado da área distal, transferido para cobrir a raiz desnuda e suturado no aspecto mesial do dente recipiente e interproximalmente para evitar tensão. Os dentes experimentais, os caninos direitos, foram submetidos a controle de placa a cada 2 dias. Os dentes controle, os caninos esquerdos, placa bacteriana foi deixada acumular livremente. Um animal foi sacrificado nos dias 1, 7, 21, 36 e 98 dias após a cirurgia. Cortes histológicos foram preparados para microscopia ótica. Os resultados mostraram que se um controle de placa eficiente for feito a porção coronal da superfície radicular será coberta por um epitélio juncional longo, enquanto um tecido conjuntivo denso e maduro estará aderido na porção apical da superfície radicular


Subject(s)
Animals , Dogs , Cuspid/cytology , Guided Tissue Regeneration , Dental Plaque/veterinary , Surgical Flaps/veterinary , Biometry , Connective Tissue/anatomy & histology , Gingival Recession/veterinary
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