Dentin Proteins Research Articles

Chios gum mastic enhance the proliferation and odontogenic differentiation of human dental pulp stem cells.

Dental pulp stem cells (DPSCs) are a type of adult stem cell present in the dental pulp tissue. They possess a higher proliferative capacity than bone marrow mesenchymal stem cells. Their ease of collection from patients makes them well-suited for tissue engineering applications, such as tooth and nerve regeneration. Chios gum mastic (CGM), a resin extracted from the stems and leaves of Pistacia lentiscus var. Chia, has garnered attention for its potential in tissue regeneration. This study aims to confirm alterations in cell proliferation rates and induce differentiation in human DPSCs (hDPSCs) through CGM treatment, a substance known for effectively promoting odontogenic differentiation. Administration of CGM to hDPSC cells was followed by an assessment of cell survival, proliferation, and odontogenic differentiation through protein and gene analysis. The study revealed that hDPSCs exhibited low sensitivity to CGM toxicity. CGM treatment induced cell proliferation by activating cell-cycle proteins through the Wnt/β-catenin pathway. Additionally, the study demonstrated that CGM enhances alkaline phosphatase activation by upregulating the expression of collagen type I, a representative matrix protein of dentin. This activation of markers associated with odontogenic and bone differentiation ultimately facilitated the mineralization of hDPSCs. This study concludes that CGM, as a natural substance, fosters the cell cycle and cell proliferation in hDPSCs. Furthermore, it triggers the transcription of odontogenic and osteogenic markers, thereby facilitating odontogenic differentiation.

Dentinogénesis imperfecta: reporte de un caso

Introducción: La dentinogénesis imperfecta (DI) es una alteración hereditaria que se origina en la etapa de histodiferenciación durante la odontogénesis, constituyendo una forma de displasia mesodérmica localizada, caracterizada por una expresa alteración de las proteínas dentinarias. Se clasifica en dentinogénesis tipo I (relacionada con osteogénesis imperfecta), DI tipo II (no relacionada con OI) y DI tipo III (de Brandynwine). Objetivo: Determinar el tipo de dentinogénesis, tendencia familiar y características clínicas del paciente, para establecer un diagnóstico temprano y el patrón hereditario que presenta. Presentación del caso: Paciente masculino de 3 años de edad, acudió a consulta por hipersensibilidad dental y molestia durante la masticación; presentó una alteración de estructura y color de los órganos dentales presentes, abscesos, atricción y pérdida de la dimensión vertical, radiográficamente se observa obliteración pulpar, marcada constricción cervical y raíces cortas. Después de los análisis clínico y radiográfico, historia familiar e interconsulta con genética se descartó OI y se estableció el diagnóstico de dentinogénesis imperfecta tipo II, de carácter autosómico dominante, sin predilección de sexo. Se restauró con coronas de acero cromo y se realizaron las extracciones necesarias, continuando con la colocación de mantenedores de espacio y prótesis parciales removibles. Conclusión: Debido a que en los pacientes con DI, la primera dentición se ve más afectada, es de suma importancia realizar un diagnóstico temprano para iniciar cuanto antes un tratamiento adecuado. En este tipo de pacientes es imprescindible llevar a cabo interconsulta con genética para descartar su asociación con otras entidades.

Endogenous Enzymatic Activity in Dentin Treated with a Chitosan Primer.

The aim of this study was to evaluate the effect of different concentrations of chitosan polymer on dentinal enzymatic activity by means of gelatin and in situ zymography. Human dentin was frozen and ground in a miller. Dentin powder aliquots were demineralized with phosphoric acid and treated with three different concentrations of lyophilized chitosan polymer (1, 0.5 and 0.1 wt%) dissolved in distilled water. Dentin proteins were extracted from each experimental group and electrophoresed under non-reducing conditions in 10% SDS-PAGE containing fluorescein-labeled gelatin. After 48 h in the incubation buffer at 37 °C, proteolytic activity was registered under long-wave UV light scanner and quantified by using Image J software. Furthermore, additional teeth (n = 4) were prepared for the in situ zymographic analysis in unrestored as well as restored dentin pretreated with the same chitosan primers. The registered enzymatic activity was directly proportional to the chitosan concentration and higher in the restored dentin groups (p < 0.05), except for the 0.1% chitosan primer. Chitosan 0.1% only showed faint expression of enzymatic activity compared to 1% and 0.5% concentrations. Chitosan 0.1% dissolved in water can produce significant reduction in MMPs activity and could possibly contribute to bond strength preservation over time.

DSPP dosage affects tooth development and dentin mineralization.

Dentin Sialoprotein (DSP) and phosphophoryn (PP) are two most dominant non-collagenous proteins in dentin, which are the cleavage products of the DSPP (dentin sialophosphoprotein) precursor protein. The absence of the DSPP gene in DSPP knock-out (KO) mice results in characteristics that are consistent with dentinogenesis imperfecta type III in humans. Symptoms include thin dentin, bigger pulp chamber with frequent pulp exposure as well as abnormal epithelial-mesenchymal interactions, and the appearance of chondrocyte-like cells in dental pulp. To better understand how DSPP influences tooth development and dentin formation, we used a bacterial artificial chromosome transgene construct (BAC-DSPP) that contained the complete DSPP gene and promoter to generate BAC-DSPP transgenic mice directly in a mouse DSPP KO background. Two BAC-DSPP transgenic mouse strains were generated and characterized. DSPP mRNA expression in BAC-DSPP Strain A incisors was similar to that from wild-type (wt) mice. DSPP mRNA expression in BAC-DSPP Strain B animals was only 10% that of wt mice. PP protein content in Strain A incisors was 25% of that found in wt mice, which was sufficient to completely rescue the DSPP KO defect in mineral density, since microCT dentin mineral density analysis in 21-day postnatal animal molars showed essentially identical mineral density in both strain A and wt mice. Strain B mouse incisors, with 5% PP expression, only partially rescued the DSPP KO defect in mineral density, as microCT scans of 21-day postnatal animal molars indicated a reduced dentin mineral density compared to wt mice, though the mineral density was still increased over that of DSPP KO. Furthermore, our findings showed that DSPP dosage in Strain A was sufficient to rescue the DSPP KO defect in terms of epithelial-mesenchymal interactions, odontoblast lineage maintenance, along with normal dentin thickness and normal mineral density while DSPP gene dosage in Strain B only partially rescued the aforementioned DSPP KO defect.

Sodium Hypochlorite and Chlorhexidine Downregulate MMP Expression on Radicular Dentin

Objective: Matrix metalloproteinases (MMPs) are present in radicular dentin and can convert structural matrix proteins into signaling molecules; thus, these enzymes play an essential role in dentin biomineralization and tissue regeneration therapies. Their expression on radicular dentin may be affected by the irrigation solutions used during root canal treatments. This study aimed to evaluate the effects of the most common irrigants on radicular dentin MMP expression. Materials and Methods: The experimental solutions were distilled water (control), 5% sodium hypochlorite (NaOCl), 18% ethylenediaminetetraacetic acid (EDTA), and 2% chlorhexidine (CHX). Samples were prepared from extracted human teeth. For zymography analysis, root sections were powderized, and dentin proteins were extracted to observe gelatinolytic activity. Root dentin slices were treated with the experimental solutions for immunohistochemical analysis using anti-MMP-2 and anti-MMP-9 antibodies. ANOVA and the Tukey test were performed. Results: Zymograms revealed the presence of MMP-2, MMP-8, and MMP-20 in the control group and the EDTA-treated group. Immunohistochemistry confirmed the presence of MMP-2 and MMP-9 mainly associated with the dentinal tubule lumens and occasionally with intertubular dentin. NaOCl- and CHX-treated groups showed lower expression of MMPs than the control group. Immuno­staining for both proteinases in the EDTA-treated group showed higher expression compared to the other experimental groups. Conclusion: Our results showed that most common irrigants affect MMP expression on radicular dentin. Treatment with NaOCl and chlorhexidine resulted in lower expression of MMPs, while EDTA increased their expression in root canal dentin.

The Collagen Family: Biosynthesis and Degradation - Oral Pathologies Induced by Genes Mutations

Mutations, deletion, insertions, and DNA splicing are involved in many pathologies of the oral sphere. Type I collagen is the major structural protein of bone and dentin. The genetic disease affects more than 1 in 10,000 individuals, and is characterized by fragile bones, skeletal deformities, frequent bone fractures, or even prenatal death. In addition to osteogenesis imperfecta (OI) and dentinogenesis imperfecta (DI), collagen mutations produce Ehlers-Danlos syndrome (EDS), and Alport, Marfan, and Good pasture syndromes. The different forms of the collagen super family include the fibril-forming collagens, collagen forming a network (basement membrane), membrane collagen, and anchoring fibrils. This family of molecules comprises 28 members. For type I collagen collagen is formed by a-chains, cross banded at regular intervals of 67nm. Synthetized as procollagen (with a N- and C-propeptide), the terminal extensions are cleaved by zinc-dependent endopeptidases. Hydroxyproline, hydroxylysine and glycine, are present at every third position. Epidermolysis bullosa are due to collagen gene mutations, or either to the gene coding for cellular cytokeratins (type K5 and/or K14). Mutations are reaching the extra cellular anchoring filaments of the basement membrane (involved in junctional EB),or mutations of the collagen located in the papillary and reticular layers (dystrophic EB - DEB). Osteogenesis imperfecta and some other bone pathologies are detectable in the oral cavity. Mutations od collagens, such as oral submucous fibrosis, diabetes mellitus, kidney and squamous cell carcinoma, are the consequences of genetic diseases involved directly in several areas of the body, or interfering indirectly with the tissues if the oral cavity. Some drugs improve the symptoms of the diseases.

Non-Collagenous Dentin Protein Binding Sites Control Mineral Formation during the Biomineralisation Process in Radicular Dentin.

The biomineralisation of radicular dentin involves complex molecular signalling. Providing evidence of protein binding sites for calcium ions and mineral precipitation is essential for a better understanding of the remineralisation process. This study aimed to evaluate the functional relationship of metalloproteinases (MMPs) and non-collagenous proteins (NCPs) with mineral initiation and maturation during the biomineralisation of radicular dentin. A standardized demineralisation procedure was performed to radicular dentin slices. Samples were remineralised in a PBS-bioactive material system for different periods of time. Assessments of ion exchange, Raman analysis, and energy dispersive X-ray analysis (EDAX) with a scanning electron microscope (SEM) were used to evaluate the remineralisation process. Immunohistochemistry and zymography were performed to analyse NCPs and MMPs expression. SEM evaluation showed that the mineral nucleation and growth occurs, exclusively, on the demineralised radicular dentin surface. Raman analysis of remineralised dentin showed intense peaks at 955 and 1063 cm−1, which can be attributed to carbonate apatite formation. Immunohistochemistry of demineralised samples revealed the presence of DMP1-CT, mainly in intratubular dentin, whereas DSPP in intratubular and intertubular dentin. DMP1-CT and DSPP binding sites control carbonate apatite nucleation and maturation guiding the remineralisation of radicular dentin.

IMMUNOHISTOCHEMICAL EXPRESSION OF AMELOGENIN AND DENTIN SIALOFOSFOPROTEIN IN TEETH WITH AMELOGENESIS IMPERFECTA, DENTINOGENESIS IMPERFECTA AND REGIONAL ODONTODYSPLASIA

Objective To compare the immunohistochemical expression of amelogenin (Amelx) and dentin sialofosfoprotein (DSPP) in teeth with Amelogenesis imperfecta (AI), dentinogenesis imperfecta (DI) and regional odontodysplasia (RO). Study Design In the present study we included patients who signed informed consent and agree to donate exfoliated deciduous teeth and third molars. This study analyzed six teeth with hypoplastic AI (HpAI), five teeth with hypocalcified AI (HcAI) three cases of Hipomature AI (HmAI), two teeth with DI and two teeth with RO and seven normal teeth. All cases were non-syndromic forms. Amelx C-19 and Amelx F-11 antibodies were used to detect amelogenin, and DSPP antibodies LFMb 21 and ab122321 were used for DSPP. For the characterization and diagnosis of each case anamnesis, clinical and radiographic examination was performed. Results AI cases: Only in cases of HcAI was sufficient enamel matrix left after decalcification, in these cases Amelx was detected in the interrods region. In dentine Amelx was not detected, DSPP was detected in peritubular dentin in most cases. DI cases When decalcifying these teeth, the enamel was lost. In dentin, DSPP was only detected with the Ab122321 antibody in the peritubular area. The antibody LFMb21 was negative in dentin. RO cases Temporary tooth enamel marked positive for Amlex and for DSPP. the dentin of the temporal tooth marked scarce marking for DSPP. In the permanent tooth the enamel was lost when decalcifying and in dentine no DSPP was detected. Conclusions The teeth with AI lost the enamel when decalcifying, except those with HcAI that presented Amelx in the enamel matrix. Dentin presented normal distribution of DSPP in AI teeth. The teeth with DI did not present DSPP in dentin. The teeth with OR presented anomalous marking of these proteins in enamel and dentin.

Proteomics and N-glycoproteomics analysis of an extracellular matrix-based scaffold-human treated dentin matrix.

Extracellular matrix (ECM)-based biomaterials developed from mammalian tissues have been successfully used in preclinical and clinical tissue engineering applications. We have previously reported about the applicability of dentin-based scaffold, treated dentin matrix (TDM), for tooth root regeneration. However, TDM protein composition has not been characterized. Here, we used a shotgun proteomic strategy to profile human TDM proteome. N-glycoproteins were enriched by lectin affinity chromatography and identified by mass spectrometry. The total human TDM proteome was compared with the previously published human dentin proteome, and bioinformatics analysis were performed accordingly. In total, 708 proteins were identified by mass spectrometry in human TDM, of which 208 were N-glycoproteins with 318 identified glycosylation sites. Collagens, proteoglycans, small integrin-binding ligand N-linked glycoproteins (SIBLINGs), and growth factors, such as COL1A1, biglycan, dentin sialoprotein, and transforming growth factor beta 1, were identified. Glycoproteins were enriched in "biological processes" Gene Ontology terms such as cellular process, biological regulation, response to stimulus, metabolic process, immune system process, and biological adhesion. Thus, our comprehensive study of the human TDM proteome revealed that dentin proteins are more heterogeneous than previously documented. Our findings provide clues for designing new biomaterials for tooth root regeneration and understanding dentin formation.

Neurotrophic Proteins in Dentin and Their Effect on Trigeminal Sensory Neurons

IntroductionA plethora of bioactive molecules present during tooth formation become sequestered in the mineralized dentin matrix and can be released into the pulp tissue after demineralization from carious lesions. However, neurotrophic factors are differentially expressed and secreted during various stages of odontogenesis. Thus, the aims of this study were(1) to investigate their presence and relative abundance in crown and root dentin and(2) to evaluate the bioactivity of dentin-derived proteins on neuronal cells. MethodsDentin matrix proteins (DMPs) were isolated from matched roots and crowns of extracted healthy human third molars. The total protein amount as well as the concentration of growth factors and neurotrophic proteins were quantified. The impact on neuritogenesis was determined with mouse trigeminal neurons in vitro and by a hydrogel implant model in vivo. Transient receptor potential cation channel subfamily V member 1 (TRPV1) sensitization of DMP-conditioned neurons was evaluated by single-cell calcium imaging. ResultsThe relative concentration of neurotrophic molecules revealed that nerve growth factor is the most abundant neurotrophin with 3-fold increased expression in radicular dentin. Similarly, brain-derived neurotrophic factor and neurotrophin 3 are more abundant in radicular than coronal dentin. Conversely, glial cell line–derived neurotrophic factor is more abundant in coronal dentin, whereas neurotrophin 4 is equally distributed. Dentin matrix proteins promoted neurite outgrowth in vitro and axonal targeting in vivo, with a greater effect observed by radicular dentin extracts. Furthermore, DMPs sensitized TRPV1 responses in mouse trigeminal neurons with greater activity seen with extracts from root dentin. ConclusionsNeurotrophic factors are differentially distributed between coronal and radicular dentin with different effects of dentin-derived proteins on axonal growth and targeting as well as the sensitization of TRPV1. Thus, extracellular proteins from the dentin matrix are likely involved in neurogenic responses to caries and could be exploited in clinical regenerative endodontics to promote reinnervation and enhance tissue regeneration.

Shotgun Proteomics of Human Dentin with Different Prefractionation Methods

Human dentin is not only a composite material of a collagenous matrix and mineral to provide strength and elasticity to teeth, but also a precious reservoir full of bioactive proteins. They are released after demineralization caused by bacterial acids in carious lesions, by decalcifying irrigants or dental materials and they modulate tissue responses in the underlying dental pulp. This work describes a first-time analysis of the proteome of human dentin using a shotgun proteomic approach that combines three different protein fractionation methods. Dentin matrix proteins were extracted by EDTA and separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), OFFGEL isoelectric focusing (IEF) or strong cation exchange chromatography (SCX). Liquid chromatography tandem mass spectrometry (LC-MS/MS) identified 813 human proteins with high confidence, however, isoelectric focusing turned out to be the most beneficial prefractionation method. All Proteins were categorized based on the PANTHER system and representation analysis revealed 31 classes and subclasses to be overrepresented. The acquired knowledge provides a comprehensive insight into the number of proteins in human dentin as well as their physiological and pathological functions. Thus, the data presented paves the way to the analysis of specific functions of dentin matrix proteins in vivo and their potential in tissue engineering approaches to regenerate dental pulp.

The functional significance of dentin sialoprotein-phosphophoryn and dentin sialoprotein

Phosphophoryn (PP) and dentin sialoprotein (DSP) are the most dominant non-collagenous proteins in dentin. PP is an extremely acidic protein that can function as a mineral nucleator for dentin mineralization. DSP was first identified in 1981, yet its functional significance is still controversial. Historically, these two proteins were considered to be independently synthesized and secreted by dental pulp cells into the developing dentin matrix. However, with the identification of the DSP coding sequence in 1994, followed 2 years later by the finding that the PP coding sequence was located immediately downstream from the DSP sequence, it became immediately clear that DSP and PP proteins were derived from a single DSP-PP (i.e., dentin sialophosphoprotein, DSPP) transcript. Since DSPP cDNA became available, tremendous progress has been made in studying DSP-PP mRNA distribution and DSP generation from the DSP-PP precursor protein at specific cleavage sites by protease tolloid-related-1 (TLR1) or bone morphogenetic protein 1 (BMP1). The functions of DSP-PP and DSP were investigated via DSP-PP knockout (KO) and DSP knockin in DSP-PP KO mice. In addition, a number of in vitro studies aimed to elucidate DSPP and DSP function in dental pulp cells.

Biochemical and immunohistochemical identification of MMP-7 in human dentin

ObjectivesMatrix metalloproteinases (MMPs) are dentinal endogenous enzymes claimed to have a vital role in dentin organic matrix breakdown. The aim of the study was to investigate presence, localization and distribution of MMP-7 in sound human dentin. MethodsDentin was powdered, demineralized and dissolved in isoelectric focusing buffer. Resolved proteins were transferred to nitrocellulose membranes for western blotting (WB) analyses. For the zymographic analysis, aliquots of dentin protein were electrophoresed in 12% sodium dodecyl sulfate-polyacrylamide gel electrophoresis containing fluorescently labeled gelatin. Further, the concentrations of dentinal MMPs were measured using Fluorescent Microsphere Immunoassay with a human MMP-MAP multiplex kit. Pre- and post-embedding immunolabeling technique was used to investigate the localization and distribution of MMP-7 in dentin. Dentin was cryo-fractured, the fragments partially decalcified and labeled with a primary monoclonal anti-MMP-7 and a secondary antibody conjugated with gold nanoparticles. MMP-7 labelings were identified in the demineralized dentin matrix as highly electron-dense dispersed gold particles. ResultsWB and zymographic analysis of extracted dentin proteins showed presence of MMP-7 (∼20–28 KDa). Further, MMP-7 was found in the supernatants of the incubated dentin beams using Fluorescent Microsphere Immunoassay. FEI-SEM and TEM analyses established MMP-7 as an intrinsic constituent of the human dentin organic matrix. ConclusionThis study demonstrated that MMP-7 is an endogenous component of the human dentin fibrillar network. Clinical significanceIt is pivotal to understand the underlying processes behind dentin matrix remodeling and degradation in order to develop the most optimal clinical protocols and ensure the longevity of dental restorations.

Functionalized epigallocatechin gallate copolymer inhibit dentin matrices degradation: Mechanical, solubilized telopeptide and proteomic assays

ObjectivesWe investigated the biostability of dentin organic matrices treated with epigallocatechin gallate (EGCG) in comparison to chlorhexidine (CHX), both extracted from functionalized copolymers. MethodsCopolymers were prepared with bis-GMA:TEGDMA and incorporated with 1% of EGCG or CHX (w/w). Blank copolymers were used as control. Copolymer samples were individually stored in 1mL deionized water to produce copolymer extracts. Dentin matrices were obtained by demineralization of dentin disks in 10% phosphoric acid solution. Matrices were individually treated with 1mL of the copolymer extracts or distilled water for 48h. Collected extracts were analyzed by high-performance liquid chromatography (HPLC) for the presence and quantification of EGCG, CHX, and copolymer by-products. Treated dentin matrices were tested for ultimate tensile strength, gravimetric changes, and swelling ratio. The treatment media were tested for total protein concentration, and dentin protease activity through solubilized telopeptide (ICTP- and CTX-ELISA) assays. The treatment media were also submitted to proteomic analysis. ResultsHPLC identified released unreacted copolymer species and showed higher release of CHX compared to EGCG from respective copolymer extracts. EGCG extract inhibited activity of dentin proteolytic enzymes and promoted collagen biomodification observed by the telopeptide assays and in the changes to dentin matrix properties. The proteomic results showed less collagenous peptide hits in the EGCG extract media compared to CHX, and suggest compound-specific dentin protein binding interactions. SignificanceThis study demonstrates specific antiproteolytic effect and protein interactions of EGCG copolymer extract directly on dentin. This represents an advancement in dental materials which can impact the clinical procedures.

Multiphoton Microscopy for Caries Detection with ICDAS Classification

Dentin carious lesion is a dynamic process that involves demineralization and collagen denaturation. Collagen type I is the major protein in dentin and it has been investigated based on its optical properties. Multiphoton microscopy (MPM) is a nonlinear imaging technique that reveals the caries process using the collagen two-photon excitation fluorescence (2PEF) and its second-harmonic generation (SHG). Combining the histological and the International Caries Detection and Assessment System (ICDAS) classifications with nonlinear optical spectroscopy (NLOS), 2PEF and SHG intensities of enamel and dentin were highly altered during the caries process. It has been proven that the ratio SHG/2PEF is a relevant indicator of the organic matrix denaturation [Terrer et al.: J Dent Res 2016; 96: 574–579]. In the present study, a series of measurable signals is made to detect early stages of carious lesion according to the ICDAS classification and to explore the relationship between these measures and the ICDAS scale. Comparison of the efficiency of nonlinear optical signals for caries detection with the ICDAS classification is essential to evaluate their potential for clinical application. In our study, the use of the NLOS measured by MPM allowed us to monitor a quantitative parameter (SHG/2PEF ratio) according to the dentin carious lesion state (ICDAS and histological examination). Three coherent new groups were defined (ICDAS 0/1; ICDAS 2/3; ICDAS 4/5/6), where the carious process can be clearly described with a statistically significant decrease of the SHG/2PEF ratio.

Comparison of Commercial Calcium Hydroxide Pastes for Prolonged Antibacterial Effect using a Colourimetric Assessment.

The anti-microbial activity of calcium hydroxide pastes used in endodontics is dependent on establishing high levels of hydroxyl ions in dentine. This study investigated hydroxyl ion diffusion from different commercial calcium hydroxide pastes using a novel colourimetric method. In this method, human tooth roots were stained with anthocyanin dye, which changed their colour according to the local pH conditions. Prepared root canals were filled with pastes formulated with the vehicle of water (Pulpdent™, Calasept Plus™), polyethylene glycol (PEG) (Calmix™) or a mixture of water, PEG and ibuprofen (Odontocide™). The changes in dye colour at fixed distances from the canal wall were monitored using standardised digital photography over a period of 3 weeks. A repeated measures analysis tracked changes in each root from baseline. Release of hydroxyl ions varied between the different commercial compositions containing water or PEG as solvents. The colour changes in the dentine, due to released hydroxyl ions, were greatest and more prolonged for completely non-aqueous compositions, when using PEG 400 as the vehicle. When water was present in the product, the duration of the pH changes was shorter. This was attributed to the presence of hydroxyl ions in the water (the common-ion effect) and a more vigorous buffering of hydroxyl ions by dentine proteins.

Imperfecta Dentinogenesis: a case report

Summary: Introduction: Dentinogenesis imperfecta (DI) is an inherited dental diaseasein which dental crowns are affected. DI originates by defects on the histo-differenciation stage ofodontogenesis, constituting a localized mesodermal dysplasia characterized by an expressedalteration of dentin proteins. There are three types of dentinogenesis imperfecta: Type I(associated with osteogenesis imperfecta OI), type II (no associated with OI), and type III(Brandywine’s). Objectives: To determine the type of dentinogenesis imprefecta, the family historyand clinical characteristics of a patient within extensive coronal destruction, to establish aprecise diagnosis and a treatment to recover masticatory function. Case Report: A 3-year-old malechild was referred to the clinic with dental hypersensitivity and pain during mastication. Hepresented generalized and extensive crown destructions and discoloration of erupted teeth,abscesses, attrition and loss of vertical dimension. Radiographs showed obliterated pulp chambers,marked cervical constriction and short roots. After clinical and radiographic analysis, familyhistory and consultation with a Geneticist, a relation with OI was not established. In contrast, adiagnosis of dentinogenesis imperfecta type II was confirmed. DE type II is an autosomyc dominanttrait, without gender predilection. Restorative treatment involved stainless steel crowns, requiredextractions, space maintainers and removable partial dentures placement. Conclusion: Early diagnosisand treatment of DI is recommended because the severe destruction of primary dentition that mayaffect child chewing and nutrition. Consultation wit a Geneticist in DI cases is reccomended todiscard any association with OI or other genetic syndromes. Key words: Dentinogenesis imperfecta.Odontogenesis imperfecta. Opalescent dentin. Hereditary opalescent dentin.

Could the application of bioactive molecules improve vital pulp therapy success? A systematic review.

This study aimed to systematically review the literature of animal studies to evaluate whether bioactive dentin proteins could improve vital pulp therapy success. The review is reported in accordance with the PRISMA Statement. Two reviewers independently conducted a literature search of seven databases: PubMed (Medline), Lilacs, IBECS, BBO, Web of Science, Scopus, and SciELO. Animal experiments in which bioactive dentin proteins were applied directly or indirectly to the pulp tissue were included. Data regarding the characteristics of the proteins evaluated, the delivery systems used and the main findings from each study were tabulated to assess the outcomes of interest (tertiary dentin formation, inflammatory response, intratubular mineralization). After screening, 32 papers were subjected to qualitative analysis. In 75% of the studies, direct pulp capping was performed. Additionally, the most studied proteins were BMP-7, TGF-β1, and extracted soluble dentin matrix proteins. In conclusion, there is evidence in the literature suggesting that bioactive dentin molecules could enhance tertiary dentin formation with fewer initial inflammatory responses in direct and indirect pulp therapy in animal models. There are potential areas to be explored for novel therapeutic approaches for dental tissue repair and regeneration with bioactive materials. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 941-956, 2017.

Immediate Autogenous Fresh Demineralized Tooth (Auto-FDT) Graft for Alveolar Bone Reconstruction

Ideal autogenous or allogenic bone graft materials should provide 1) stabilization of blood clot, 2) scaffolds for cellular proliferation and differentiation, 3) release of osteogenic growth factors, 4) appropriate resorption profile for remodeling of new bone. Teeth, especially dentin, mostly contain hydroxyapatite and type I collagen which are similar to bone, and could be valuable graft material. Clinically teeth are used as calcined or demineralized forms. Demineralized form of dentin can be more effective as a graft material. But a conventional decalcification method takes time and long treatment time may give negative effects to various osteogenic proteins in dentin. Author used a new clinical method to prepare autogenous teeth, which could be grafted into the removal defects immediately after extraction using vacuum ultrasonic system. The process could be finished within two hours regardless of the form (powder, chip or block). Teeth were processed to graft materials in block, chip, or powder types immediately after extraction. It took 120 minutes to prepare block types and 40 minutes to prepare powder. Clinical cases did not show any adverse response and the healing was favorable. Rapid preparation of autogenous teeth with the vacuum ultrasonic system could make the immediate one-day extraction and graft possible.

Effects of Non-Collagenous Proteins, TGF-β1, and PDGF-BB on Viability and Proliferation of Dental Pulp Stem Cells.

ABSTRACTObjectivesThe dentin matrix servers as a reservoir of growth factors, sequestered during dentinogenesis. The aim of this study was to assess the viability and proliferation of dental pulp stem cells in the presence of dentin matrix-derived non-collagenous proteins and two growth factors; platelet-derived growth factor BB and transforming growth factor beta 1.Material and MethodsThe dental pulp cells were isolated and cultured. The dentin proteins were extracted and purified. The MTT assay was performed for assessment of cell viability and proliferation in the presence of different concentrations of dentin proteins and growth factors during 24 - 72 h post-treatment.ResultsThe cells treated with 250 ng/mL dentin proteins had the best viability and proliferation ability in comparison with other concentrations (P < 0.05). The MTT assay demonstrated that cells cultured with 5 ng/mL platelet-derived growth factor BB had the highest viability at each time point as compared to other groups (P < 0.05). However, in presence of platelet-derived growth factor BB alone and in combination with transforming growth factor beta 1 and dentin proteins (10 ng/mL), significant higher viability was seen at all time points (P < 0.05). The least viability and proliferation at each growth factor concentration was seen in cells treated with combination of transforming growth factor beta 1 and dentin proteins at 72 h (P < 0.05).ConclusionsThe results indicated that the triple combination of growth factors and matrix-derived non-collagenous proteins (especially at 10 ng/mL concentration) has mitogenic effect on dental pulp stem cells.