Investigation of the effect of indirect pulp capping materials on dentin mineral density

Aim: To evaluate the potential of inducing mineral density changes of indirect pulp capping materials applied to demineralized dentin. Methods: A total of 50 cavities were prepared, 5 in each tooth, in extracted ten molars without caries, impacted or semi-embedded. The cavities were scanned by microcomputed tomography (µ-CT) after creating artificial caries by microcosm method (pre-treatment). Each cavity was subjected to one of 5 different experimental conditions: control (dental wax), conventional glass ionomer cement (Fuji IX GP Extra), resin-modified calcium silicate (TheraCal LC), resin-modified calcium hydroxide (Ultra-Blend Plus), MTA (MM-MTA) and the samples were kept under intrapulpal pressure using simulated body fluid for 45 days. Then, the second µ-CT scan was performed (post-treatment), and the change in dentin mineral density was calculated. Afterward, elemental mapping was performed on the dentinal surfaces adjacent to the pulp capping agents of 5 randomly selected samples using energy dispersive X-ray spectroscopy (EDS) apparatus attached to a scanning electron microscope (SEM). The Ca/P ratio by weight was calculated. Friedman test and Wilcoxon Signed Ranks test were used to analyze the data. Results: There was a significant increase in mineral density values of demineralized dentin after treatment for all material groups (p<0.05). Resin-modified calcium silicate had similar efficacy to MTA and conventional glass ionomer cement, but was superior to resin-modified calcium hydroxide in increasing the mineral density values of demineralized dentin. Conclusions: Demineralized dentin tissue that is still repairable can be effectively preserved using materials with remineralization capability

Response of dental pulp capped with calcium-silicate based material, calcium hydroxide and adhesive resin in rabbit teeth

Direct pulp capping induces a local inflammatory process. Several biomaterials have been used for this procedure. The aim of this study was to compare the dentinal bridge thickness using three different pulp capping biomaterials with the conventional technique (high speed diamond bur) or Er-Yag laser, 1 month after pulp effraction. Materials and Methods: Forty two Class V cavities were prepared on the buccal surface of 4 maxillary incisors and 2 mandibular incisors of New Zealand rabbits. Specimens were divided into 6 treatment groups. Teeth were treated with: In Group 1: Er-Yag laser and Biodentine® (Septodont), in Group 2: Er: Yag laser and calcium hydroxide (Dycal® Dentsply), in Group 3: Er: Yag laser and adhesive system (Prime& Bond® NT Dentsply), in Group 4: high speed diamond bur and Biodentine® (Septodont), in Group 5: high speed diamond bur and calcium hydroxide (Dycal® Dentsply), and in Group 6: high speed diamond bur and adhesive system (Prime& Bond® NT Dentsply). The preparation was done with copious irrigation. The animals were sacrificed at 30 days and the teeth were extracted and prepared for histological analysis. Results: In the group of « laser Er-Yag ¼, iatrogenic pulpal wounds treated with Biodentine® were covered with a thick hard tissue barrier after 1 month. The difference was not significant with the groups of Dycal® used with Er: Yag laser and high speed diamond bur. Prime& Bond® NT Dentsply specimens showed a thin dentinal bridge layer. Conclusion: At 1 month, Er-Yag laser proved to be useful with Biodentine® for direct pulp capping procedures

A comparative evaluation of the sealing ability of two calcium silicate based sealers and a resin epoxy-based sealer through scanning electron microscopy and bond strength: an in vitro study

Aim: this study aimed to compare the sealing ability of two types of commercially available calcium silicate bioceramic based root canal sealers and a resin based root canal sealer. Methods: Twenty one single-rooted teeth were used, samples (n= 21) were randomly divided into three groups according to the sealer used (group A; ADSEAL, group B; Wellroot, group C; Ceraseal). Roots were then cleaved longitudinally in the labiolingual direction; all samples were then sectioned at three, six, and nine mm from the root tip. The penetration of sealers into the dentinal tubules was examined at 1000x with a scanning electron microscope. Data were tested for normality using Shapiro Wilk test. ANOVA test was used for analyzing normally distributed data followed by Bonferroni post hoc test for pair-wise comparison. Significance level p≤0.001. Results: groups B and C showed better sealing ability than group A in all the three sections. The coronal section showed higher sealing ability than the middle section followed by the apical section in the three tested groups. Conclusion: it can be concluded that both calcium silicate-based sealers had better sealing ability and higher bond strength than the resin epoxy- based sealer

Reparación Ósea en Alvéolos de Ratas Ovariectomizadas con Biosilicato Cristalizado. Análisis Histomorfométrico / Alveolar Bone Repair in Ovarictomized Rats with Crystallized Biosilicate. Histomorphometric Analysis

RESUMEN: Evaluar el proceso de reparación alveolar en ratas sometidas a cirugía de simulacro u ovariectomizadas tras el relleno alveolar con coágulo o con biosilicato cristalino. Sesenta ratas Wistar fueron divididas en cuatro grupos (n=15) de acuerdo con el tratamiento: Grupo 1- ratas sometidas a cirugía de simulacro con alveolos rellenados con coágulo; Grupo 2- ratas sometidas a cirugía de simulacro con alveolos rellenados con biosilicato cristalino; Grupo 3- ratas ovariectomizadas con alveolos rellenados con coágulo; Grupo 4- ratas ovariectomizadas con alveolos rellenados con biosilicato cristalino. Después de 7, 14 y 28 días, los animales fueron sacrificados, se tomaron muestras óseas que fueron teñidas con hematoxilina-eosina y analizadas al microscopio para realizar un análisis histomorfométricos. Los mayores porcentajes de formación de hueso se presentaron en los grupos 1 (32 % a los 7 días, 46 % a los 14 días y 83.5 % a los 28 días) y 4 (27,1 % a los 7 días, 41,1 % a los 14 días y 79,7 % a los 28 días). En los alveolos rellenados con coágulo, las ratas sometidas a cirugía de simulacro mostraron los mejores resultados, mientras que, en los alveolos rellenados con biosilicato, las ratas ovariectomizadas tenían porcentajes significativamente mayores. En este estudio, el biosilicato cristalino se comportó como un biomaterial adecuado para la reparación ósea, favoreciendo la osteoconducción.

ABSTRACT: The objective of this study was to assess the process of alveolar bone repair in rats subjected to sham surgery or ovariectomized rats, after alveolar filling with clot or with crystalline biosilicate. Sixty Wistar rats were divided into four groups (n = 15) according to the treatment: Group 1 - rats subjected to sham surgery with sockets filled with clot; Group 2- rats submitted to sham surgery with sockets filled with crystalline biosilicate; Group 3 ovariectomized rats with sockets filled with clot; Group 4 ovariectomized rats with sockets filled with crystalline biosilicate. After 7, 14 and 28 days, the animals were sacrificed, bone samples were taken, stained with hematoxylin-eosin and analyzed under a microscope to perform a histomorphometric analysis. The highest percentages of bone formation were presented in groups 1 (32 % at 7 days, 46 % at 14 days and 83.5 % at 28 days) and 4 (27.1 % at 7 days, 41.1 % at 14 days and 79.7 % after 28 days). In the sockets filled with clot, the rats subjected to sham surgery showed the best results, while in the sockets filled with biosilicate, the ovariectomized rats had significantly higher percentages. In this study, the crystalline biosilicate behaved as an adequate biomaterial for bone repair, favoring osteoconduction.

Cerámicas: una actualización / Ceramics: an update / Cerâmica: uma atualização

Las cerámicas dentales utilizadas para restaurar y reemplazar tejido dental perdido de los dientes o las piezas dentales mismas, han sufrido una enorme transformación desde que aparecieron las primeras porcelanas hace ya varias décadas. Con las feldespáticas se podían hacer dientes, coronas y puentes pero, necesitaban un soporte de metal para que no sufran fracturas con los esfuerzos masticatorios, y por ello no tenían una apa-riencia vital. Hoy en día, han aparecido muchas otras cerámicas con diferentes y mejoradas características mecánicas y ópticas, lo que ha permitido que los odontólogos puedan por primera vez ofrecer a sus pacientes dientes artificiales con sorprendente naturalidad. Objetivo: Describir la clasificación actual, las características mecánicas y ópticas, así como la microestructura y los usos clínicos de las diferentes cerámicas dentales utilizadas hoy en día. Materiales y métodos: Revisión de la literatura acerca del tema, en tres de los más importantes buscadores de internet (Pubmed,Cochrane,Web of Science). Limitando su busca a artículos en inglés y publicados en los journals de investigación de materiales dentales con calificación Q1 y Q2. Resul-tados: Se revisaron 69 artículos publicados entre 1975 y 2019 los cuales aportaron una fuente interesante de información que permitió desarrollar el conocimiento acerca de la clasificación, microestructura, propiedades mecánicas y ópticas, usos clínicos y forma de procesamiento de las cerámicas. Conclusiones: Actualmente los odontólogos tienen a disposición una amplia variedad de materiales cerámicos con diferentes composicio-nes y características únicas que son necesarias conocer al momento de escoger la cerámica específica para cada necesidad de los pacientes.

The dental ceramics used to restore and replace lost tooth tissue or the teeth have undergone a huge trans-formation since the first porcelains appeared several decades ago. With the feldspathic teeth, crowns and bridges could be made but, they needed a metal support so that they did not suffer fractures with the mastica-tory efforts, and therefore they did not have a vital appearance. Today, many other ceramics with different and improved mechanical and optical characteristics have appeared, which has allowed dentists to offer artificial teeth to their patients for the first time with surprising naturalness. Objective: Describe the current classifica-tion, mechanical and optical characteristics, as well as the microstructure and clinical uses of the different dental ceramics used today. Materials and methods: Review about the literature on the subject, in three of the most important internet search engines (Pubmed, Cochrane, Web of Science). Limiting your search to articles in English and published in the journals of research of dental materials with qualification Q1 and Q2. Results:69 articles published between 1975 and 2019 were reviewed, which provided an interesting source of informa-tion that allowed the development of knowledge about classification, microstructure, mechanical and optical properties, clinical uses and method of processing ceramics. Conclusions: Currently, dentists have available a wide variety of ceramic materials with different compositions and unique characteristics that are necessary to know when choosing the specific ceramic for each patient need.

A cerâmica dentária usada para restaurar e substituir o tecido dentário perdido ou as próprias peças dentárias sofreram uma enorme transformação desde que as primeiras porcelanas surgiram várias décadas atrás. Com os materiais feldespáticos, podiam ser feitas coroas e pontes, mas eles precisavam de um suporte de metal para não sofrer fraturas com os esforços mastigatórios e, portanto, não tinham uma aparência de vitalidade. Hoje, outras cerâmicas com características mecânicas e ópticas diferentes e aprimoradas surgiram, o que permitiu aos dentistas oferecer dentes artificiais a seus pacientes pela primeira vez com uma naturalidade surpreendente. Objetivo: Descrever a classificação atual, características mecânicas e ópticas, bem como a microestrutura e os usos clínicos das diferentes cerâmicas odontológicas utilizadas atualmente. Materiais e métodos: Revisão da literatura sobre o assunto, em três dos mais importantes mecanismos de busca na In-ternet (Pubmed, Cochrane, Web of Science). Limitando a sua pesquisa a artigos em inglês e publicados nas revistas científicas de materiais dentários com qualificação Q1 e Q2. Resultados: Foram revisados 69 artigos publicados entre 1975 e 2019, que forneceram uma fonte interessante de informações que permitiram desen-volver conhecimento sobre a classificação, microestrutura, propriedades mecânicas e ópticas, usos clínicos e forma de processamento da cerâmica. Conclusões: Atualmente, os dentistas têm disponível uma ampla variedade de materiais cerâmicos com composição diferente e características únicas que são necessárias conhecer ao escolher a cerâmica específica para cada necessidade do paciente.

Evaluation of the dislodgement resistance of bioceramic reparative cements placed in a retrograde cavity using a different technique

Aim: Calcium silicate-based fillings have been widely used in surgical endodontic treatment because of hard-tissue conductive and inductive properties. The aim of present study is to investigate the bond strength of different calcium silicate-based fillings in retrograde cavities. Methods: Forty-four maxillary single rooted teeth were endodontically treated. The apical portions of the teeth were removed and root-end cavities were prepared using an ultrasonic tip. The roots were randomly divided into four experimental groups (n = 11) according to the material used; (1) MTA-FILLAPEX, (2) MTA Repair HP, (3) MTA-FILLAPEX+ MTA Repair HP, and (4) MTA Plus. Two horizontal cross sections (1±0.1 mm thick) from each specimen were resected from the apices. These sections were placed in a universal testing machine to evaluate the push-out bond strength force required for dislodgement of the root end filling was recorded. The failure type was also evaluated by using a stereomicroscope. The differences in bond strength were analyzed using the two-way analysis of variance (ANOVA). Results: MTA-FILLAPEX and MTA Plus displayed the lowest and highest dislocation resistance, respectively (P < 0.05). In the apical level, bond strength was significantly higher than the coronal level in all groups except for MTA-FILLAPEX. Mixed failure was prevalent in all groups, except for MTA-FILLAPEX, which showed purely cohesive failures. Conclusions: Investigated calcium silicate-based filling materials showed different bond strength to the root-end cavity. The bond strength was significantly decreased when the prior application of MTA-FILLAPEX before delivery of MTA Repair HP

A Case of Cement Hardening Agent Intoxication with Acute Kidney Injury

Chronic silica nephropathy has been associated with tubulointerstitial disease, immune-mediated multisystem disease, chronic kidney disease, and end-stage renal disease. On the other hand, acute intentional exposure is extremely rare. The authors' experienced a 44-year-old man who took rapid cement hardener (sodium silicate) in a suicide attempt whilst in a drunken state. He visited the emergency department approximately 1 hour after ingestion. Information on the material was obtained after 3 L gastric lavage. The patient complained of a sore throat, epigastric pain, and swollen to blood tinged vomitus. Proton pump inhibitors, hemostats, steroid, and fluids were administered. Nine hours after ingestion, he was administered 200 mL hematochezia. Immediately after, a gastroenterologist performed an endoscopic procedure that revealed diffuse hyperemic mucosa with a color change and variable sized ulceration in the esophagus, whole stomach, and duodenal 2(nd) portion. Approximately 35 hours later, persistent oligouria and progressive worsening of the renal function parameters (BUN/Cr from 12.2/1.2 to 67.5/6.6 mg/dL) occurred requiring hemodialysis. The patient underwent 8 sessions of hemodialysis for 1 month and the BUN/Cr level increased to 143.2/11.2 mg/dL and decreased to 7.6/1.5 mg/dL. He was discharged safely from the hospital. Follow up endoscopy revealed a severe esophageal stricture and he underwent endoscopic bougie dilatation. Acute cement hardener (sodium silicate) intoxication can cause renal failure and strong caustic mucosal injury. Therefore, it is important to consider early hemodialysis and treatment to prevent gastrointestinal injury and remote esophageal stricture.

Recent advances in direct pulp capping materials / 华西口腔医学杂志

The long-term effect of direct pulp capping and pulpotomy is closely related to the type of pulp capping materials. Various kinds of direct pulp capping materials are available, such as calcium hydroxide and mineral trioxide aggregates. Diverse new pulp capping materials have been reported recently. The excellent performance of calcium silicates has attracted much attention in previous studies. Moreover, enamel matrix derivative (Emdogain), which is capable of regeneration and remineralization, and other materials with similar capabilities have shown potential for use in pulp capping.

Influence of macro-pore bone block on osteogenic activity and mechanical property in vivo / 中华骨科杂志

Objective To observe and identify the osteogenic activity,biocompatibility and mechanical property of a type of macro-pore bone block bioactive glass in rabbits.Methods Establish the femoral condyle defect model with New Zealand white rabbit.Implant in the defect with macro-pore bone block bioglass,β-TCP and NOVABONE(R) respectively.According to the different materials implanted in the defect,three groups were divided as macro-pore bone block bioglass group,β-TCP group and NOVABONE group.After the surgery,X-ray examination was performed to confirm the location and fixation of the materials and to observe the femoral condyle fracture.The specimens were harvested at 4,12 and 24 weeks after the surgery respectively.MicroCT was performed to assess the new bone formation and degradation of the materials.Tetracycline-calcein double labeling was used to detect the mineral apposition rate of new bone.Van Gieson staining was used to assess the new bone formation percentage.Biomechanical markers including the compress strength and elasticity modulus were also measured.Results X-ray examination showed that each femoral defect was filled fully with materials and the materials were all in proper position.As indicated by MicroCT results,at 24 weeks,the bone regeneration volume fraction of each group was 37.48％ ±0.70％,25.29％± 1.45％,27.03％±1.25％ respectively and the difference between macro-pore bone block group and β-TCP group or NOVABONE group was statistically significant.The residual material volume fraction of each group was 34.67％±3.52％,55.66％±2.05％,7.52％± 1.15％ respectively and the difference between macro-pore bone block group and β-TCP group or NOVABONE group was statistically significant.The results of tetracycline-calcein double labeling showed that the mineral apposition rate in macro-pore bone block bioglass group,β-TCP group and NOVABONE group at 4 weeks was (1.577±0.045) um/d,(2.064±0.068)um/d,(1.19±0.09)um/d respectively and the difference between macro-pore bone block bioglass group and β-TCP group was statistically significant.As shown by the results of Van Gieson staining,the new bone area percentage of macro-pore bone block bioglass group,β-TCP group and NOVABONE group was 5.43％± 1.25％,2.77％±0.85％,6.51％± 1.21％ at 4 weeks,8.48％±0.84％,2.94％±0.65％,11.42％±2.66％ at 12 weeks,23.55％± 1.13％,12.92％±0.45％,19.53％±0.91％ at 24 weeks.The difference between macro-pore bone block bioglass group and β-TCP group or NOVABONE group at 24 weeks was statistically significant.By biomechanical test,the compress strength of specimens in macro-pore bone block bioglass group and β-TCP group increased as time prolonged,with no statistically significant between the two groups.The elasticity modulus of specimens in macro-pore bone block bioglass group and NOVABONE group was stable after surgery,closer to the rabbit bone,while elasticity modulus of the β-TCP group increased a lot,unsuit to the rabbit bone.Conclusion Macro-pore bone block bioglass presented good biological activity,biocompatibility and suitable biomechanical properties.This research loaded foundation for the application in weight-bearing sites of this new material.

Eficiência de escórias de siderurgia na cultura do feijoeiro em sistema de semeadura direta / Efficiency of steel slag in the common bean crop in the no-till system

No sistema de semeadura direta (SSD), a prática da correção da acidez do solo se restringe ao uso do calcário, havendo poucas informações em relação às escórias de siderurgia. O trabalho objetivou avaliar as alterações em propriedades químicas do solo, rendimento e absorção de nutrientes do feijoeiro, em função das formas de aplicação de escórias de siderurgia, comparadas ao calcário, na implantação do sistema de semeadura direta. O experimento foi conduzido na área experimental da Faculdade de Ciências Agronômicas de Botucatu (SP), no período de dezembro de 2010 a maio de 2011. Os tratamentos foram duas formas de aplicação de sete corretivos da acidez do solo: escórias de aciaria, de alto forno, de forno de panela, do aço inox (agrosilício), wollastonita, calcário dolomítico e calcário dolomítico calcinado, além de uma testemunha sem aplicação de corretivo. A dose aplicada de cada corretivo foi calculada para elevar a saturação por bases do solo a 70. A acidez do solo foi neutralizada até a camada de 20cm com os calcários, enquanto a wollastonita e escória de forno de panela atingiram a camada de 10cm; para as escórias de aciaria, alto forno e o agrosilício, o efeito corretivo ficou restrito aos primeiros 5cm. O rendimento do feijoeiro aumentou com a aplicação de corretivos da acidez do solo, sem diferença entre o modo de aplicação.

In the no till system, soil acidity correction practice is restricted to limestone use and there is little information regarding slag. The study aimed to evaluate the amendments in soil chemical properties, yield and bean nutrient uptake according to the application forms of slags, compared to limestone, in the implantation of no till system. The experiment was conducted in the field at College of Agricultural Sciences, Botucatu (SP) from December 2010 to May2011. The treatments consisted of two application ways of seven soil acidity correctives: steel slag, blast furnace slag, ladle furnace slag, stainless steel slag (“agrosilício”), wollastonite, lime and calcined dolomite lime, plus one control without corrective application. Each material dose was calculated to raise the base saturation to 70%. Soil acidity was neutralized down to 20cm with limestones, whereas for wollastonite and ladle furnace slag those effects occurred down to 10cm, for steel slag, blast furnace slag and “agrosilício” the corrective effect was restricted to the first 5cm. The bean yield increased by application of correctives in soil acidity, without differences between the application ways.

In vivo study of five porous bioceramic scaffolds implanted in animal muscle / 中华骨科杂志

ObjectiveTo investigate the in vivo biological performance of 5 porous bioceramic scaffolds,which were bioglass,β-tricalcium phosphate (β-TCP),hydroxyapatite (HA),β-calcium silicate (β-CS) and α-CS,implanted in rabbit dorsal muscle.MethodsThe 5 porous bioceramic scaffolds were fabricated by adding pore-forming materials and sintering,and then were investigated by X-ray diffraction,porosity mensuration and biomechanics test.The scaffolds were implanted into rabbit dorsal muscle for 4,8,12,16 weeks,respectively.The samples were analyzed by X-ray,Micro-CT,histological analysis,scanning electron microscope (SEM) and energy dispersive spectrometer (EDS).The expression of bone morphogenetic protein(BMP-2) and BMP-7 in the muscle in touch with bioceramic scaffolds were also investigated by polymerase chain reaction(PCR).ResultsThe characteristic analysis of 5 scaffolds showed that the sequence of compressive strength was bioglass＞α-CS＞β-CS＞β-TCP＞HA,the sequence of elasticity modulus was α-CS＜β-TCP＜HA＜β-CS＜bioglass.It was confirmed by X-ray,Micro-CT and histological analysis that the sequence of biodegradability was β-CS＞α-CS＞β-TCP＞bioglass＞HA.The histological observation showed no new bone formation in five scaffolds.A Ca-P layer was formed in the surface of bioglass,α-CS and β-CS,which suggested their in vivo bioactivity.After 16 weeks,the expression of BMP-2 and BMP-7 was found only in β-CS.Conclusion The porous calcium silicate scaffold,which was promising for bone tissue engineering,was with good in vivo bioactivity and biodegradability,without in vivo osteoinductivity.

Efeito de nutrientes combinados com indutores de resistência na proteção contra a vassoura-de-bruxa no cacaueiro / Effect of nutrients combined with inducers of resistance on the protection of cocoa seedlings against witches' broom

Na busca por novos indutores de resistência contra a vassoura-de-bruxa no cacaueiro avaliou-se o efeito de vários nutrientes, acibenzolar-S-metil (ASM) e a combinação desses nutrientes com ASM. Os produtos e as misturas foram pulverizados 30 dias antes da inoculação nas mudas do clone SIC-23. Foram utilizados os produtos comerciais Supa-potássio®(silicato de potássio), Hortifós® PK (fosfito de potássio) e Broadacre® Mn (sulfato de manganês), testados nas dosagens 2,5 mL; 5,0 mL; 10 mL/L de água, isoladamente ou combinados com ASM (0,2g/L). O experimento foi conduzido no delineamento de blocos ao acaso, no esquema fatorial, com quatro repetições de doze plantas/parcela. A incidência da doença foi avaliada 60 dias após a inoculação. Somente o ASM promoveu controle significativo da vassoura-de-bruxa. Os nutrientes aplicados isoladamente não apresentaram efeito na severidade da doença. Por outro lado, o efeito protetor do ASM desapareceu quando este foi misturado ao Supa-potássio®, na dose de 5 ou 10 mL/L.

Aiming at improving the level of induction of resistance in cocoa, various nutrients, acibenzolar-S-methyl (ASM) and their combination were tested on cocoa seedlings, clone SIC-23, 30 days before inoculation. The commercial products Supa-potássio® (potassium silicate), Hortifós® PK (potassium phosphite) and Broadacre® Mn (manganese sulfate) were sprayed at doses of 2.5, 5.0 mL and 10.0 mL per liter of water, combined or not, with ASM® (0.2 g/L). The experiment was set in a randomized block design, in a factorial scheme, with four replicates of twelve plants each. Disease incidence was assessed 60 days after inoculation. Only ASM promoted significant control of the disease. Nutrients alone had no effect on disease incidence. On the other hand, the protective effect of ASM disappeared when this product was mixed to Supa-potássio at 5 or 10 mL/L.