Histological study of platelet-rich fibrin combined with MTA for direct pulp capping of rabbit teeth / 口腔疾病防治

Objective @# To investigate the outcomes of a novel direct pulp capping agent containing platelet-rich fibrin (PRF) and mineral trioxide aggregate (MTA). @*Methods @# A total of 32 New Zealand rabbits were randomly divided into 4 groups, namely, the PRF+MTA group (P+M group), PRF group (P group), MTA group (M group) and blank control group (BC group), with 8 rabbits per group. Dental pulp exposure and direct pulp capping were performed, and complete crown square sealing was performed on 2 mandibular central incisor teeth of each rabbit. Four rabbits from each group were euthanized after each observation period (7 and 28 days). The experimental teeth were subjected to HE staining. Inflammatory cell infiltration, calcified bridge formation and pulp tissue disorganization were observed and graded. @*Results@#Inflammatory cell infiltration: on the 7th day, group P+M and group M were lighter than group BC (P<0.05); on the 28th day, group P+M was lighter than group P and group BC (P<0.05); group P+M and group M did not significantly differ (P>0.05). Calcified bridge formation: on the 7th and 28th days, group P+M was lighter than group P, group M and group BC (P<0.05); on the 28th day, group M was higher than group BC (P<0.05). Under microscope, the calcified bridge contained cellular components and was surrounded by odontoblast-like cells, sharing a structure resembled osteodentin; dentin tubule-like structure could not be observed in calcified bridge, and the calcified bridge resembled certain points of osteodentin. Pulp tissue disorganization: on the 7th day, group P+M and group M were lighter than group BC (P<0.05); on the 28th day, group P+M was lighter than group P and group BC (P<0.05). group P+M and group M did not significantly differ (P>0.05). @*Conclusion @# The combination of PRF and MTA for direct pulp capping provided light inflammatory cell infiltration, stable pulp status and a strong ability of pulp tissue to form calcified bridge, and the calcified bridge resembled certain points of osteodentin.

Use of pulp tissue of deciduous teeth for gender determination - A comparative molecular analysis study

Aim: The present study aimed to evaluate the effectiveness of pulp tissue collected from deciduous teeth for the determination of gender using polymerase chain reaction (PCR). Materials and Methods: 140 extracted deciduous teeth were selected. The control group comprised 20 teeth that were subjected to DNA analysis immediately. Whereas Group I and Group II consisted of 60 teeth which were stored in the open environment and salt water, respectively, for a period of 3, 9, and 15 months. DNA was isolated and quantified followed by the amplification of X and Y chromosomes by PCR and compared with the actual gender of the child. The data were analysed using the Shapiro?Wilk test, the independent sample t?test, paired t?test, and the Chi?square test. Result: The PCR analysis results of Group I showed a more correct interpretation of gender as compared to Group II on storage for a period of 15 months. The PCR analysis results of the Control group showed a 100% accuracy rate as compared to the samples in Groups I and II. Conclusions: Gender could be effectively determined from the samples evaluated immediately after extraction. But the period of storage and the method of storage conditions affected the quality of isolated DNA and thus decreased the ability of gender determination

Human pulp tissue dissolution ability of different extracts of Sapindus mukorossi: An in vitro study / 中草药·英文版

Objective: Due to the many negative properties of sodium hypochlorite used in current root canal treatment, interest in biocompatible natural agents is increasing day by day. The aim of this study was to evaluate whether various extract solutions of Sapindus mukorossi have dissolution effects on human pulp tissues. Methods: Primarily powder extracts were obtained by extracting fruit shells of S. mukorossi in different solvents (ethanol, methanol, buthanol and distilled water). The test solutions were prepared and randomly separated into six groups with 10 samples in each group: ethanol extract, methanol extract, butanol extract, distilled water extract of S. mukorossi, sodium hypochlorite (NaOCl) and the control group. Among these, S. mukorossi extracts were separated into two subgroups, depending on their concentration level (50 µg/mL and 100 µg/mL). The pulp tissues of freshly extracted human molars were used for dissolution test. The weights of the pulpal tissues were measured and recorded for two times after the samples were placed in the solutions. Statistical analysis for all descriptive statistics was performed using SPSS 22 (P < 0.05). Results: Our results showed that maximum percent yield of preparation was obtained in methanol extract of S. mukorossi. Among all of the groups, the best dissolution capacity was seen in the NaOCl group (positive control group). Among S. mukorossi groups, the best tissue solvent solution was found in SMM group at 50 µg/mL and SMB group at 100 µg/mL. Conclusion: The different extracts of S. mukorossi had a capacity to dissolve pulp tissue but this capacity was less than NaOCl. Therefore, further studies will enable the creation of a commercial solution for clinical use by increasing the effectiveness of S. mukorossi while combining it with other endodontic irrigation solutions.

Research progress in pulp tissue regeneration strategy in microenvironment / 国际生物医学工程杂志

Pulpal and periapical diseases are the common diseases in human diseases. The traditional treatment method for these diseases is root canal treatment, which is to completely remove and control infection, repair or prevent periapical lesions by root canal mechanical preparation, chemical disinfection and filling. At present, although root canal treatments have a high success rate, there are still a series of problems. Dental pulp regeneration has attracted more and more attention from researchers in promoting the formation of pulp-like tissue in root canals. The ultimate goal of regenerative endodontics is to form a functional endodontic-dentin complex with inner blood vessels and nerves, outer layers of dentin cells arranged along the root canal wall, and new dentin formed by secreting matrix, so as to restore pulp vitality. Stem cells, scaffolds, biosignal molecules, and regenerative microenvironment are key tissue engineering factors that affect pulp regeneration. In this paper, the strategies and applications of pulp regeneration were reviewed around the above factors and clinical procedures.

The role of APOD in the proliferation and migration of human dental pulp cells / 口腔疾病防治

Objective@#To explore the role of apoliprotein D (APOD) in the proliferation and migration of human dental pulp cells (DPCs) and to provide a basis for the use of APOD to promote pulp regeneration. @*Methods@#APOD expression in human dental pulp cells was inhibited by siRNA. The inhibition effect of APOD was confirmed by qPCR and Western blot. After APOD inhibition, colony formation experiments and CCK8 assays were employed to confirm the proliferation ability of dental pulp cells. Transwell assays were used to verify the cell migration ability after the inhibition of APOD expression.@*Results @# After inhibiting APOD expression, the colony formation rate in the si-apod group was reduced compared with the NC group, and the difference was statistically significant (t=7.624, P=0.002). The CCK8 experiment showed that the OD value in the si-apod group decreased at 3, 5 and 7 d compared with that in the NC group (P < 0.05). Transwell results showed that the number of cell divisions was 57.25 ± 4.03 in the si-apod group and 154.50 ± 8.39 in the NC group, and the difference was statistically significant (t=10.45, P < 0.001).@*Conclusion@# Inhibition of APOD expression in dental pulp cells inhibits their proliferation and migration ability.

Treatment of Periodontal Bone Defects with Stem Cells from Inflammatory Dental Pulp Tissues in Miniature Swine

BACKGROUND: Containing a certain proportion of mesenchymal stem cells, inflammatory dental tissue showed great tissue regeneration potential in recent years. However, whether it is applicable to promote tissue regeneration in vivo remains to be elucidated. Therefore, we evaluated the feasibility of stem cells from inflammatory dental pulp tissues (DPSCs-IPs) to reconstruct periodontal defects in miniature pigs. METHODS: The autologous pig DPSCs-IPs were first cultured, appraised and loaded onto β-tricalcium phosphate (β-TCP). The compounds were then engrafted into an artificially-created periodontal defect. Three months later, the extent of periodontal regeneration was evaluated. Clinical examination, radiological examination and immunohistochemical staining were used to assess periodontal regeneration. RESULTS: The data collectively showed that DPSCs-IPs from miniature pigs expressed moderate to high levels of STRO-1 and CD146 as well as low levels of CD34 and CD45. DPSCs-IPs have osteogentic, adipogenic and chondrogenic differentiation abilities. DPSCs-IPs were engrafted onto β-TCP and regenerated bone to repair periodontal defects by 3 months' post-surgical reconstruction. CONCLUSION: Autologous DPSCs-IPs may be a feasible means of periodontal regeneration in miniature pigs.

Locations of TLR4 in healthy dental pulp tissue and dental pulp tissue affected by deep caries / 口腔疾病防治

Objective@#To analyze the role of TLR4 in innate immune response of dental pulp by comparing the locations and expressions of TLR4 in healthy dental pulp tissue and dental pulp tissue affected by deep caries. @*Methods @# Healthy teeth and teeth affected by deep caries were demineralized and stained with hematoxylin and eosin (HE) to observe the morphology of dental pulp. Immunohistochemistry staining was performed to observe the expressions of TLR4.@*Results @# Observed under HE staining, dentin tubules of teeth affected by deep caries were damaged with a lot bacteria mass. The expression of TLR4 were located in the odontoblast layer and near the blood vessels in both groups. Positive staining of TLR4 in deep caries pulps (2.10±0.74) were significantly higher than that in healthy teeth (1.25 ±0.46). @*Conclusion @#Expression of TLR4 in deep caries pulp is stronger than that in healthy pulp. It suggests that TLR4 may play a role in the innate immune response of deep caries.

Pulp Tissue Dissolution Capacity of Sodium Hypochlorite Combined with Cetrimide and Polypropylene Glycol

This study evaluated the influence of the addition of cetrimide and polypropylene glycol to sodium hypochlorite (NaOCl) on its capacity to dissolve pulp tissue. Bovine pulp fragments with standardized weight and volume were immersed for 5, 15 and 30 min in 2 mL of NaOCl and Hypoclean (NaOCl added with cetrimide and polypropylene glycol) solutions at 5.25%, 2.5%, 1%, 0.5% and 0.25% and afterwards re-weighted. Distilled water was used as a control. The percentage of tissue loss was considered for statistical analysis (univariate ANOVA, SPSS, v. 17.0) at 5% significance level. There was no tissue dissolution in the control group. NaOCl added with surfactants (Hypoclean) dissolved more pulp tissue (p<0.05) than NaOCl alone. Tissue dissolution was directly dependent on the concentration of solutions (p<0.05), and also on the time range (p<0.05). The combination of NaOCl at high and low concentrations with the surfactants cetrimide and polypropylene glycol increased significantly its capacity to dissolve pulp tissue.

Este estudo avaliou a influência da adição de cetramida e polipropilenoglicol ao hipoclorito de sódio (Hypoclean) na capacidade de dissolução pulpar do hipoclorito de sódio (NaOCl). Fragmentos de tecido pulpar bovino, com peso e volume padronizados foram imersos por períodos de 5, 15 e 30 min em 2 mL de NaOCl ou Hypoclean nas concentrações 5,25%, 2,5%, 1%, 0,5% e 0,25%. Após a imersão nas soluções testadas, os fragmentos foram novamente pesados. Como controle, foi utilizada água destilada. O percentual de perda tecidual foi considerado para análise estatística (ANOVA univariada, SPSS, v. 17.0). Não houve dissolução tecidual no grupo controle. A solução de NaOCl combinada a surfactantes (Hypoclean) dissolveu um maior percentual de tecido pulpar (p<0,05) que o NaOCl sem associações. A dissolução tecidual foi diretamente dependente da concentração das soluções (p<0,05), assim como do tempo de exposição às soluções (p<0,05). A adição dos surfactantes cetramida e polipropilenoglicol ao NaOCl em concentrações altas e baixas aumentou significativamente sua capacidade de dissolução do tecido pulpar.

Pulp tissue dissolution when the use of sodium hypochlorite and EDTA alone or associated / Dissolução do tecido pulpar quando do uso do hipoclorito de sódio e EDTA isoladamente ou associados

PURPOSE: The aim of the present study was to evaluate the tissue dissolving capacity of various concentrations of sodium hypochlorite either alone or in combination with 17 percent EDTA. METHODS: Eighty bovine pulp fragments were prepared, and their weight was determined using a precision balance. Each pulp fragment was immersed for 2 hours in a solution/mixture that was based on the following groups: G1 - saline solution; G2 - 0.5 percent NaOCl; G3 - 1.0 percent NaOCl; G4 - 2.5 percent NaOCl; G5 - 17 percent EDTA; G6 - 0.5 percent NaOCl+17 percent EDTA; G7 - 1.0 percent NaOCl+17 percent EDTA; and G8 - 2.5 percent NaOCl+17 percent EDTA. The final weight was measured, and the weight loss was calculated. A statistical analysis was performed using either the Student's t-test for paired samples or an ANOVA and Tukey tests (P<0.05 was considered to be significant). RESULTS: We measured a significant difference between the sample weight before and after treatment for each of the tested groups (P<0.05). The 2.5 percent sodium hypochlorite solution (G4) completely dissolved the pulp tissue within the test period. NaOCl+EDTA was less effective than sodium hypochlorite alone at dissolving the pulp tissue (P<0.05), and EDTA alone (G5) did not markedly dissolve the pulp tissue. CONCLUSION: Using EDTA together with NaOCl reduced the tissue dissolving properties compared with NaOCl alone, regardless of the concentration of NaOCl that was used.

OBJETIVO: O objetivo do presente estudo foi avaliar a capacidade de dissolução tecidual de várias concentrações de hipoclorito de sódio, isoladamente ou em combinação com o EDTA 17 por cento. METODOLOGIA: Oitenta fragmentos de polpa bovina foram preparados e seus pesos foram determinados através de uma balança de precisão. Cada fragmento pulpar foi imerso por 2 horas em cada uma das soluções/misturas e formaram os seguintes grupos: G1- Solução salina; G2- NaOCl 0,5 por cento; G3- NaOCl 1 por cento; G4- NaOCl 2,5 por cento; G5- EDTA 17 por cento; G6- NaOCl 0,5 por cento + EDTA 17 por cento; G7- NaOCl 1,0 por cento + EDTA 17 por cento; G8- NaOCl 2,5 por cento + EDTA 17 por cento. O peso final foi medido e a perda de peso calculada. A análise estatística foi realizada através do teste t de Student para amostras pareadas, ou ANOVA e teste de Tukey. RESULTADOS: Verificaram-se diferenças entre os pesos das amostras antes e depois do tratamento para cada um dos grupos testados (P< 0,05). A solução de hipoclorito de sódio 2,5 por cento (G4) dissolveu completamente o tecido pulpar dentro do período teste. O hipoclorito de sódio + EDTA foi menos efetivo na dissolução do tecido pulpar do que o hipoclorito de sódio sozinho (P < 0,05), e o EDTA (G5) não dissolveu o tecido pulpar. CONCLUSÃO: O uso do EDTA misturado com o hipoclorito de sódio reduziu a propriedade de dissolução tecidual comparado ao hipoclorito de sódio sozinho, a despeito das concentrações de hipoclorito de sódio.

Pulp tissue regeneration and root formation of permanent teeth with pulpal/periapical deseases / 대한치과보존학회지

Numerous cases about additional growth of roots or pulp tissue regeneration by using various intracanal medicaments in immature permanent teeth with periapical or pulpal disease have been reported. The underlying mechanism has not been clearly delineated, but it has been widely accepted that undifferentiated mesenchymal cells and stem cells are involved. Moreover, the growth and deposition of osteoid or cementoid tissues have been observed in regenerated pulp and roots. This new and non-invasive treatment has brightened the future of endodontics, and enlarged the vision of regenerative root canal treatment with multi-potent stem cells and various tissue engineering techniques.

Análise do padrão de expressão de MMP-2, -9 e -8 em tecido humano pulpar normal e inflamado / Analysis of the expression perfile of MMP-2, -9 and -8 in normal and inflamed human pulp tissue

As metaloproteinases da matriz (MMPs) foram relacionadas a diversas doenças inflamatórias como artrite e também ao câncer. O presente trabalho tem por objetivo estabelecer o papel da MMP-2, MMP-9 e MMP-8 no processo de inflamação pulpar. Foram adotadas as seguintes hipóteses nulas: (1) o padrão de expressão das MMP-2, MMP-9 e MMP-8 não sofre alteração nos diferentes estágios da polpa humana: normal, reversível, transição, irreversível ou necrose; (2) não há diferença de expressão das MMP-2, -9 e MMP-8, considerando-se um mesmo estágio de inflamação tecidual pulpar. Os métodos utilizados foram: (I) Obtenção dos espécimes, que foram divididos em grupos de acordo com critérios adotados de semiologia subjetiva e objetiva. Obtiveram-se os seguintes grupos: GI (Controle) dentes hígidos (n=7); GII (Pulpite Reversível n=4); GIII (Pulpite Transição n=4); GIV (Pulpite Irreversível/Necrose n=8). Logo após exodontia, os dentes obtidos foram cortados ligeiramente abaixo da junção amelodentinária e fixados em formol a 10% por 48h. Foram lavados em água corrente (24h) para então serem processados histologicamente. Foram obtidas secções de 4m, aderidas em lâminas silanizadas e submetidas à imunomarcação (Técnica da Peroxidase), utilizando os anticorpos anti MMP-2, MMP-9 e MMP-8 humanos. A presença de imunomarcação foi realizada através da análise semi-quantitativa por escores, sendo que a quantificação de marcação por corte seguiu o seguinte escore: 0= ausente; 1= leve; 2= moderada; 3= intensa. Realizou-se teste estatístico não paramétrico Kruskal-Wallis, p<0,05. As comparações intergrupos revelaram, para CO: (1)MMP-2 - GI=GII=GIII, GIII=GIV, GI>GIV (p<0,01) e GII>GIV (p<0,05); (2)MMP-9 GI=GII=GIV, GII=GIII e GIII>GI (p<0,01); (3)MMP-8 GI=GII=GIII=GIV. Na região central da polpa, obteve-se: (1)MMP-2 GI=GII=GIII, GIII=GIV, GI>GIV (p<0,001) e GII>GIV (p<0,01); (2)MMP-9 GI=GII=GIII, GIII=GIV, GIV>GI (p<0,001) e GIV>GII (p<0,01); (3)MMP-8 GI=GII, GIII=GIV, GIII>GI (p<0,05),...

The matrix metalloproteinases (MMPs) have been related to various inflammatory diseases, such as arthritis, as well as to cancer. The aim of the present study was to establish the role of MMP-2, MMP-9 and MMP-8 in the process of dental pulp inflammation. The following null hypotheses were adopted: (1) the pattern of MMP-2, MMP-9 and MMP-8 expression does not undergo alteration in the following different stages of human pulp: normal, reversible, transition, irreversible or necrosis; (2) there is no difference in the expression of MMP-2, -9 and MMP-8, when considering the same stage of pulp tissue inflammation. The methods used were: (I) Obtainment of specimens, which were divided into groups according to the subjective and objective criteria of semiology adopted. The following groups were obtained: GI (Control) healthy teeth (n=7); GII (Reversible Pulpitis n=4); GIII (Transition Pulpitis n=4); GIV (Irreversible Pulpitis/Necrosis n=8). Soon after extraction the teeth obtained were cut slightly below the amelodentinal junction and fixed in 10% formol for 48h. They were washed under running water (24h) and were histologically processed afterwards. Sections of 4m were obtained, adhered to silanized slides, and submitted to immunomarking (Peroxidase Technique), using human anti MMP-2, MMP-9 and MMP- 8 antibodies. The presence of immunomarking was determined through semi-quantitative analysis by scores, and marking by cut was quantified using the following score: 0= absent; 1= slight; 2= moderate; 3= intense. The Kruskal-Wallis non-parametric statistical test was performed, p<0.05. Intergroup comparisons revealed the following: for CO: (1)MMP-2 - GI=GII=GIII, GIII=GIV, GI>GIV (p<0.01) and GII>GIV (p<0.05); (2)MMP-9 GI=GII=GIV, GII=GIII and GIII>GI (p<0,01); (3)MMP-8 GI=GII=GIII=GIV. In the central region of the pulp, the following results were obtained: (1)MMP-2 GI=GII=GIII, GIII=GIV, GI>GIV (p<0.001) and GII>GIV (p<0.01); (2)MMP-9 GI=GII=GIII, GIII=GIV, GIV>GI...

Interleukin-8 and MCP(Monocyte Chemoattractant Protein)-1 expression by the Human Dental Pulps in cultures stimulated with Substance P / 대한치과보존학회지

The induction of the IL-8 and MCP-1 by the stimulation of Substance P and TNF-alpha (IL-8 agonist) and the specificity for SP using Spantide (SP antagonist) in the dental pulp tissues was measured quantitatively. In addition, the secretion of the IL-8 in the human dental pulp tissue 36 hrs after the stimulation of SP was observed after the stimulation of SP qualitatively. According to this study, the results were as follows: 1. There was the significant IL-8 induction at 36 h after SP (10-4M) stimulation of the pulp tissue comparing with the unstimulated dental pulp tissues (p < 0.05). IL-8 immunostaining was weakly detected along the periphery of the pulp tissue after Mock stimulation and IL-8 immunostaining was detected around the fibroblast in the pulp tissue 36h After SP (10-4M) stimulation, 2. The secretion of MCP-1 from the dental pulp tissues comparing with Mock stimulation was induced at 36 hrs after TNF-alpha (40 ng/ml) stimulation, but no induction with SP(10-4M). TNF-alpha (40 ng/ml) did not induce the IL-8 secretion from the pulp tissue, weak IL-8 immunostaining was detected along the periphery of the pulp tissue. 3. Spantide (10-5M) inhibited IL-8 induction from the pulp tissues 36 h after SP (10-4M) stimulation. These results suggest that SP significantly induces IL-8 recruiting neutrophils in localized human dental pulp tissue. MCP-1 appears to be less involved in the early establishment of pulpal inflammation in response to irritation such as mechanical insult of dentin. SP may have positive relation with the inflammation of the human dental pulp tissues.

Tissue engineering of dental pulp on type I collagen / 대한치과보존학회지

The purpose of this study was to regenerate human dental pulp tissues similar to native pulp tissues. Using the mixture of type I collagen solution, primary cells collected from the different tissues (pulp, gingiva, and skin) and NIH 3T3 (1 x 10(5) cells/ml/well) were cultured at 12-well plate at 37degrees C for 14 days. Standardized photographs were taken with digital camera during 14 days and the diameter of the contracted collagen gel matrix was measured and statistically analyzed with student t-test. As one of the pulp tissue engineering, normal human dental pulp tissue and collagen gel matrix cultured with dental pulp cells for 14 days were fixed and stained with Hematoxyline & Eosin. According to this study, the results were as follows: 1. The contraction of collagen gel matrix cultured with pulp cells for 14 days was significantly higher than other fibroblasts (gingiva, skin) (p 0.05). 5. The collagen gel matrix cultured with pulp cells for 14 days showed similar shape with native pulp tissue without blood vessels. This approach may provide a means of engineering a variety of other oral tissue as well and these cell behaviors may provide information needed to establish pulp tissue engineering protocols.