Effect of canal medicaments triple antibiotic paste, Bio-C Temp, and Nano-silver gel activated by visible blue light on canal dentin microhardness and extrusion bond strength of AH plus sealer: A SEM and EDX analysis.

AIM: Assessment of contemporary canal medicaments (Triple antibiotic paste (TAP), Bio-C Temp, and Nano silver gel activated by visible blue light on the dentin microhardness (MH) and push-out bond strength (PBS) of AH plus endodontic sealer. METHOD: Sixty extracted premolars were obtained and decontaminated. Canal cleaning and shaping were performed. The samples were randomly allocated into four groups based on the intracanal medicaments. Group 1= CH paste, Group 2= TAP, Group 3= Bio-C Temp, and Group 4= Nano-silver gel activated by visible blue light. MH assessment was performed using a Vickers Microhardness tester. Forty specimens, ten from each group underwent root canal obturation. PBS and failure mode evaluation were performed. ANOVA and Post Hoc Tukey test were utilized to conduct intra and inter-group comparisons. RESULTS: The maximum outcome of surface hardness was presented by Group-3 (Bio-C Temp®) specimens. However, minimum scores of MH were displayed by Group 1 (CH) treated teeth. The highest outcomes of EBS were exhibited by the cervical third of Group 3 (Bio-C Temp®) samples. The apical section of Group 4 Teeth with Nano Silver gel activated by visible blue light revealed the lowest scores of bond integrity. CONCLUSION: Bio-C Temp and TAP proved to be better intracanal medicament than other tested groups in terms of the push-out bond strength of the sealer. TAP displayed lower microhardness as compared to the Bio-C Temp.

Inflammatory response to epoxy resin and calcium silicate sealers preheated with different temperatures: an in vivo study.

OBJECTIVE: To determine the impact of heat exposure of different sealers on inflammatory cytokine secretions and tissue response in vivo. MATERIALS AND METHODS: Silicone tubes were prefilled with epoxy resin (ER) or calcium silicate (CS) sealers, preheated at 37, 60, or 120 °C, and implanted in rat subcutaneous site. Peri-implant exudate and tissue were analyzed after 1 and 4 weeks for cytokine secretions and tissue organization. RESULTS: At 1 week, 120 °C-preheated CS and ER induced higher secretions of tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6), respectively, as compared to sham/empty tube groups. At 4 weeks, whereas TNF-α secretion was reduced in CS, it increased in ER group, particularly for 120 °C. Both sealers revealed high IL-6 after 4 weeks as compared to sham/empty tube, and generally, higher IL-6 secretions were associated with ER. Histology at 1 week revealed lower degree of inflammatory infiltrate in the groups of the highest preheating temperature (120 °C). Nonetheless, at 4 weeks, whereas fibrous capsule area and inflammatory infiltrate remained low in the CS120 group, they were high in ER120. CONCLUSION: Preheating ER sealer to 120 °C induced high and prolonged secretion of proinflammatory cytokines (TNF-α and IL-6), whereas this effect was transient for the CS sealer. This was associated with increased fibrous capsule and inflammatory infiltrate in response to 120 °C-preheated ER. CLINICAL RELEVANCE: Heat-induced changes in sealer properties alter the inflammatory response in vivo, which may affect the clinical outcome. This will not only help appropriate selection of obturation technique for different sealers, but also for optimizing the properties of new generation of sealers.

A comprehensive in vitro comparison of the biological and physicochemical properties of bioactive root canal sealers.

OBJECTIVES: To evaluate the biological and physicochemical features of bioactive root canal sealers. MATERIALS AND METHODS: Human periodontal ligament fibroblasts (hPDLF) and human osteoblasts (hOB) were exposed to eluates of three bioactive root canal sealers, GuttaFlow® bioseal (GF), BioRoot™ RCS (BR), and TotalFill® BC Sealer (TF), and the epoxy resin-based sealer AH plus® (AH). Cytotoxicity and cellular inflammatory response were evaluated. The osteogenic potential was examined using human mesenchymal stem cells (hMSC). Film thickness, flowability, and pH were assessed. Root canal treatment was performed on human extracted teeth to evaluate the sealers' tightness towards bacterial penetration. The antibacterial activity against common pathogens in primary root canal infections was tested. RESULTS: AH was severely cytotoxic to hPDLF and hOB (p < 0.001). The bioactive sealers were generally less cytotoxic. IL-6 levels in hPDLF were elevated in the presence of AH (p < 0.05). AH and GF suppressed IL-6 production in hOB (p < 0.05). AH and BR stimulated the PGE2 production in hPDLF and hOB (p < 0.05). BR was the only sealer that led to calcium deposits in hMSC (p < 0.05). TF and AH showed the lowest film thickness and the highest flowability. Bacterial tightness was best in teeth filled with AH and BR. All sealers showed similar antimicrobial activity, but the overall antimicrobial efficacy was moderate as the bacteria were reduced by just one log scale (p < 0.05). CONCLUSIONS: This study revealed favorable in vitro results regarding the biocompatibility of the bioactive root canal sealers. CLINICAL RELEVANCE: Bioactive root canal sealers may be a useful alternative to epoxy resin-based sealers.

Inherent Antibacterial and Instant Swelling ε-Poly-Lysine/ Poly(ethylene glycol) Diglycidyl Ether Superabsorbent for Rapid Hemostasis and Bacterially Infected Wound Healing.

Severe traumatic bleeding control and wound-related anti-infection play a crucial role in saving lives and promoting wound healing for both the military and the clinic. In this contribution, an inherent antibacterial and instant swelling ε-poly-lysine/poly (ethylene glycol) diglycidyl ether (EPPE) superabsorbent was developed by a simple mild ring-opening reaction. The as-prepared EPPE1 displayed a porous structure and rough surface and exhibited instant water-triggered expansion with approximately 6300% swelling ratio in deionized water. Moreover, EPPE1 presented efficient pro-coagulation capacity by hemadsorption that can facilitate blood cell gathering and activation in vitro and exhibited a shorter in vivo hemostasis time than that of commercial gelatin sponge and CELOX in both rat tail amputation and noncompressible rat liver lethal defect model. Also, EPPE1 showed excellent antibacterial capacity, prominent biocompatibility, and great biodegradability. Additionally, EPPE1 significantly promotes in vivo wound healing in a full-thickness skin defect model due to its great hemostasis behavior and remarkable bactericidal performance. Hence, EPPE has great potential for serving as an extensively applied hemostatic agent under varied clinical conditions.

Production of wheat germ oil containing multilayer hydrogel dressing.

A composite wound dressing has been developed by combining different layers consisting of polymers and textiles. Wheat germ oil (WGO) loaded hydrogels have successfully formed on textile nonwovens by cross-linking sodium alginate (SA) with poly(ethylene glycol) diglycidyl ether (PEGDGE). Following freeze-drying, textile-hydrogel composites have been examined according to their physical properties, pH, fluid handling capacity, water vapour permeability, morphology, chemical structure, and cytotoxicity. Hydrogels containing WGO swelled less than pristine hydrogels. Samples with 1% WGO and no WGO showed swelling of 5.9 and 10.5 g/g after 8 h. WGO inclusion resulted in reduced, but more stable fluid handling properties, with more uniform pore distribution (100-200 µm). Moreover, the proliferation of NIH/3T3 cells significantly improved with 1% WGO contained hydrogels. Also, commercial self-adhesive dressings that secure the hydrogels to the wound area were investigated regarding transfer properties. The proposed product demonstrated 8.05 cm3/cm2/s and 541.37 g/m2/day air and water vapour permeability.

Evaluation of the biocompatibility of root canal sealers on human periodontal ligament cells ex vivo.

The aim of this study was to evaluate the biocompatibility of two comparatively new calcium silicate containing sealers (MTA-Fillapex and BioRoot-RCS) with that of two established sealers (AH-Plus, epoxy resin-based; Pulp-Canal-Sealer, zinc oxide eugenol containing). Human periodontal ligament cells (PDL-cells) were brought in contact with eluates from freshly mixed and set sealer. The sealers were mixed strictly according to the manufacturers' instructions and identically samples were produced. 1:1, 1:2, and 1:10 dilutions of sealers extract were used. Extracts from freshly mixed sealer were added to the PDL-cells on day one to simulate a clinical scenario. Subsequently, at 24 h, 7, 14, and 21 days extracts form set sealers were used for PDL-cell culturing. PDL-cell viability was analyzed by living-cell-count, MTT-assay, and living/dead-staining, cytotoxicity by LDH-assay, and changes by Richardson-staining. All data were statistically evaluated by one way ANOVA and a posthoc analysis with Bonferroni-Holm testing (p < 0.05). In contact with BioRoot-RCS a regeneration of the PDL-cells were observed over time. This sealer showed the lowest toxicity in a freshly mixed and set state (p < 0.05). MTA-Fillapex and Pulp-Canal-Sealer were cytotoxic in a fresh as well as in a set state, whereas AH-Plus was cytotoxic in a freshly mixed state, but not when the sealer was set. BioRoot-RCS is biocompatible and bioactive because it seems to have a positive influence on the PDL-cell metabolism. Pulp Canal Sealer and MTA-Fillapex showed no biocompatibility in contact with PDL-cells at all. Freshly mixed AH Plus is less biocompatible on PDL than in a set state.

Comparative Biocompatibility and Osteogenic Potential of Two Bioceramic Sealers.

INTRODUCTION: Endodontic sealers have traditionally been used to seal dentinal tubules, creating a homogenous interface between the obturation material and the dentinal walls. However, bioceramic sealers have potential added benefits because of their bioactivity. After adequate endodontic therapy, osseous healing is largely dependent on the differentiation and activity of osteoblasts. We hypothesized that EndoSequence BC Sealer (Brasseler, Savannah, GA) and ProRoot ES (Dentsply Tulsa Dental Specialties, Johnson City, TN) have superior biocompatibility and osteogenic potential compared with Roth (Roth International, Chicago, IL) and AH Plus (Dentsply DeTrey Gmbh, Konstanz, Germany) sealers. METHODS: A murine osteoblast precursor cell line (IDG-SW3) was exposed to a wide range of concentrations for each of the sealers for 7 days. The relative cell viability was determined by luminescence assay based on adenosine triphosphate quantification (CellTiter-Glo [Promega, Madison, Wisconsin]). The osteogenic potential was determined by fluorescence microscopy of DMP-1 expression, alizarin red staining, and real-time reverse transcription polymerase chain reaction with primers specific for known markers of osteogenesis such as DMP-1, ALP, and Phex. Data were analyzed with 2-way analysis of variance or 1-way analysis of variance with the Bonferroni post hoc test. RESULTS: Both bioceramic sealers have excellent biocompatibility even at high concentrations. Conversely, cell death was detected when Roth and AH Plus were used at concentrations 100× lower than the bioceramic groups. Importantly, both bioceramic sealers significantly enhanced osteoblastic differentiation although greater responses were noted with EndoSequence BC Sealer. This was evidenced by increased DMP-1 expression, robust up-regulation of osteogenic marker gene expression, and superior mineral deposition. Osteoblastic differentiation and function were significantly impaired when Roth or AH Plus sealer was used. CONCLUSIONS: EndoSequence BC Sealer and ProRoot ES were significantly more biocompatible and promoted osteoblastic differentiation, a bioactivity not found in AH Plus and Roth sealers.

Hydrogels for biomedical applications from glycol chitosan and PEG diglycidyl ether exhibit pro-angiogenic and antibacterial activity.

We aimed at producing a hydrogel from a chitosan (CS) derivative soluble in physiological conditions to avoid any purification step thus allowing to use the materials also as an in-situ forming material. So, we crosslinked glycol chitosan (GCS) with poly(ethylene glycol) diglycidyl ether (PEGDE) in water at 37 °C. The scaffolds, referred as GCS-PEG, were specifically designed to be used as wound dressing materials as such (after crosslinking) or as in-situ forming materials. Different amounts of PEGDE were tested. The obtained scaffolds showed macroscopic pores and a tailorable swelling in water by controlling the crosslinking degree. Moreover, GCS-PEG scaffolds displayed a significant antimicrobial activity against Staphylococcus aureus. In-vivo study using the chick embryo choriallantoic membrane resulted in a highly pronounced pro-angiogenic activity suggesting important tissue regeneration properties. Moreover, the employed materials are commercially available, no organic solvents are required and the scaling up is quite predictable.

Novel endodontic sealers induced satisfactory tissue response in mice.

OBJECTIVES: The aim of this study was to evaluate the subcutaneous response induced by Roeko Guttaflow2 (RG), Sealapex Xpress (SX), AH Plus (AHP) sealers. METHODS: 100 BALB/c mice received implants in the subcutaneous tissue with the tested materials (10 animals per period for each evaluated sealer) and were evaluated after different experimental periods (7, 21 and 63 days), in each animal was placed a tube, the control group was an empty tube. Histological analysis evaluated semi-quantitatively the inflammatory infiltration, collagen fiber formation and tissue thickness. In addition, immunohistochemistry was performed for interleukin-6 (IL-6). Data were statistically analyzed (α = 0.05). RESULTS: RG promoted a greater collagen fiber formation at 7 days and 63 days compared to the CG (p = 0.004) and AHP (p = 0.005) respectively, while at 21 days, the SX promoted a greater reaction (p = 0.021). For the tissue thickness, there was a greater reaction at 7 days with CG (p = 0.0156) and with RG at 63 days (p = 0.03). Regarding the inflammatory infiltrate, there was no difference at 7 days and 63 days (p = 0.5; p = 0.27), while at 21 days, a statistically difference was found between SX, CG (p = 0.04) and RG (p = 0.027). In addition, the presence of IL-6 was observed in almost all groups, with a more intense marking at 7days. SIGNIFICANCE: All cements evaluated presented a satisfactory tissue response, however, RG was the one that presented a more satisfactory tissue response.

In search of the best xenogeneic material for a paediatric conduit: an experimental study.

OBJECTIVES: The development of calcification-resistant bioprosthetic materials is a very important challenge for paediatric surgery. The subcutaneous implantation in rats is the well-known first-stage model for this kind of research. Using this model, we aimed to compare calcification of the porcine aortic wall and bovine pericardium and jugular vein wall cross-linked with glutaraldehyde (GA) and ethylene glycol diglycidyl ether (DE). We also determined the efficacy of DE-preserved tissue modification with 2-(2-carboxyethylamino)ethylidene-1,1-bisphosphonic acid (CEABA). METHODS: Three groups of each biomaterial were evaluated: GA-treated, DE-treated and DE + CEABA-treated. The microstructure of non-implanted biomaterials was assessed by light microscopy after Picro Mallory staining; the phosphorus content of the DE and DE + CEABA samples was assessed by atomic emission spectrometry. Samples were implanted subcutaneously into young rats for 10 and 60 days. The explant end-point included quantitative calcification assessment by atomic absorption spectrophotometry and light microscopy examination after von Kossa staining. RESULTS: All GA-treated biomaterials had a high calcium-binding capacity (>100 µg/mg dry tissue). DE preservation decreased the vein wall and pericardium calcium content by 4- and 40-fold, respectively, but was ineffective for the aortic wall. The calculated CEABA content was almost equal in the vein wall and pericardium (17.7 and 18.5 µM/g) and slightly less in the aortic wall (15 µM/g) (P = 0.011). CEABA effectively reduced mineralization in the DE aortic wall and DE pericardium to 10.1 (7.8-21.1) and 0.95 (0.57-1.38) µg/mg but had no effect in the DE vein wall. Mineralization in the GA- and DE-treated aortic and vein walls was predominantly associated with elastin. CEABA modification decreased elastin calcification but did not block it completely. CONCLUSIONS: Each xenogeneic material requires individual anticalcification strategy. DE + CEABA pretreatment demonstrates a high mineralization-blocking efficacy for the bovine pericardium and should be employed to further develop the paediatric pericardial conduit. Aortic wall calcification cannot be blocked completely using this strategy.

In vitro antibacterial activity of a silicone-based endodontic sealer and two conventional sealers

Abstract The aim of this study was to evaluate whether the modification in the silver component is capable of providing GuttaFlow 2 with antibacterial activity against Enterococcus faecalis compared with epoxy resin-based (AH Plus) and zinc oxide and eugenol-based (Endofill) sealers. The antibacterial activity was evaluated using a reference strain of E. faecalis (ATCC 29212). Freshly mixed sealers were subjected to the agar diffusion test (ADT), while the direct contact test (DCT) was performed after materials setting. ADT results were obtained through measurements, in millimeters, of the inhibition zones promoted by the materials, using a digital caliper. In DCT, values of CFU/mL promoted by the three sealers were compared in three experimental periods (1 min, 1 h, and 24 h). The data were analyzed using Kruskal-Wallis and Dunn post-hoc tests (p < 0.05). In both ADT and DCT, GuttaFlow 2 presented no effect against E. faecalis, while Endofill and AH Plus showed similar inhibition zones. Endofill was the only material capable of reducing bacterial growth in DCT. In conclusion, modifications in the silver particle of GuttaFlow 2 did not result in a sealer with antibacterial effect against E. faecalis.

Biocompatibility and biomineralization assessment of bioceramic-, epoxy-, and calcium hydroxide-based sealers

Abstract Obturation of the root canal system aims to fill empty spaces, promoting hermetic sealing and preventing bacterial activity in periapical tissues. This should provide optimal conditions for repair, stimulating the process of biomineralization. An endodontic sealer should be biocompatible once it is in direct contact with periapical tissues. The aim of this study was to evaluate the rat subcutaneous tissue response to implanted polyethylene tubes filled with Smartpaste Bio, Acroseal, and Sealapex and investigate mineralization ability of these endodontic sealers. Forty Wistar rats were assigned to the three sealers groups and control group, (n = 10 animals/group) and received subcutaneous implants containing the test sealers, and the control group were implanted with empty tubes. After days 7, 15, 30, and 60, animals were euthanized and polyethylene tubes were removed with the surrounding tissues. Inflammatory infiltrate and thickness of the fibrous capsule were histologically evaluated. Mineralization was analyzed by Von Kossa staining and polarized light. Data were tabulated and analyzed via Kruskal-Wallis and Dunn's test. All tested materials induced a moderate inflammatory reaction in the initial periods. Smartpaste Bio induced the mildest inflammatory reactions after day 15. No difference was observed among groups after days 30 or 60. Von Kossa-positive staining and birefringent structures observed under polarized light revealed a larger mineralization area in Sealapex-treated animals followed by Smartpaste Bio-treated animals. At the end of the experiment, all tested sealers were found to be biocompatible. All sealers induced biomineralization, except Acroseal, which induced a mild tissue reaction.

Antimicrobial action of calcium hydroxide-based endodontic sealers after setting, against E. faecalis biofilm

Abstract Enterococcus faecalis are gram positive bacteria that can mostly resist endodontic therapy, inducing persistent infection in the root canal system. Endodontic sealers with antimicrobial activity may help eliminate residual microorganisms that survive endodontic treatment. The present study aimed at comparing the antimicrobial activity of Acroseal, Sealapex and AH Plus endodontic sealers in an in vitro biofilm model. Bovine dentin specimens (144) were prepared, and twelve blocks for each sealer and each experimental time point (2, 7 and 14 days) were placed and left in contact with plates containing inoculum of E. faecalis (ATCC 51299), to induce biofilm formation. After 14 days, the samples were transferred to another plate with test sealers and kept at 37°C and 5% CO2 for 2, 7 and 14 days. The specimens without sealers were used as a control for each period. The samples were agitated in a sonicator after each experiment. The suspensions were agitated in a vortex mixer, serially diluted in saline, and triple plated onto m-Enterococcus agar. Colonyforming units were counted, and the data were statistically analyzed using ANOVA, Shapiro-Wilk and Kruskal-Wallis one-way tests (p < 0.05) to determine antimicrobial potential. Sealapex showed significant differences at all the experimental time points, in comparison with all the other groups. AH Plus and Acroseal showed antimicrobial activity only on the 14th experimental day. Neither of the sealers tested were able to completely eliminate the biofilm. Sealapex showed the highest antimicrobial activity in all the experimental periods. The antimicrobial activity of all the sealers analyzed increased over time.

Evaluation of bone tissue response to a sealer containing mineral trioxide aggregate.

INTRODUCTION: This study analyzed bone tissue reactions to MTA Fillapex (Ângelus Industria de Produtos Odontológicos Ltda, Londrina, Brazil) compared with an epoxy resin-based material in the femur of Wistar rats. METHODS: Bone tissue reactions were evaluated in 15 animals after 7, 30, and 90 days (n = 5 per period). Three surgical cavities were prepared on the femur and filled with 0.2 mL MTA Fillapex, AH Plus (Dentsply DeTrey GmbH, Konstanz, Germany), or no sealer (negative control). By the end of each experimental period, 5 animals were randomly euthanized. The samples were histologically processed and analyzed using a light microscope. The presence of inflammatory cells, fibers, and hard tissue barrier formation was evaluated. Differences among the groups and between the 3 experimental periods were evaluated by using 2-way analysis of variance followed by the Bonferroni post hoc test (P ≤ .05). RESULTS: MTA Fillapex scored significantly higher for neutrophils at 7 days than at 90. At 7 days, the same occurred when comparing MTA Fillapex with AH Plus. The presence of lymphocytes/plasmocytes significantly decreased over time in all groups. Macrophages, giant cells, eosinophils, and fiber condensation presented no differences among groups and periods. Within 90 days, all groups presented complete hard tissue barrier formation. CONCLUSIONS: The presence of mineral trioxide aggregate in MTA Fillapex composition did not improve the bone tissue repair. The presence of sealers provided the re-establishment of the original bone tissue structure and the inflammatory response decreased over time, so they can be considered biocompatible.

Effects of the association of antifungal drugs on the antimicrobial action of endodontic sealers

This in vitro study aimed to determine the susceptibility of oral specimens and ATCC lineages of Candida albicans for five endodontic sealers, which were pure and associated with two antifungal drugs, and to analyze their effect on the physical properties. For this purpose, 30 lineages of C. albicans, collected from the oral cavity of patients assisted at the endodontics clinic of the Universidade Sagrado Coração, were analyzed. Yeasts susceptibility to the sealers was tested by diffusion on agar plates. Physical properties were evaluated according to the ADA specification no. 57. The pure versions of the Sealer 26, AH Plus, Endofill, Fillapex, and Sealapex demonstrated antifungal activity, with Endofill presenting the greatest inhibition zones. All cements, except for Endofill, had their antifungal actions enhanced by addition of ketoconazole and fluconazole (p < 0.05), and the AH Plus presented the best antifungal activity. The addition of antifungal drugs did not interfere with the setting time and flowability of the sealers. It was concluded that the addition of antifungals to endodontic sealers enhanced the antimicrobial action of most cements tested without altering their physical properties.

Response of human osteoblastic and osteoclastic cells to AH plus and pulp canal sealer containing quaternary ammonium polyethylenimine nanoparticles.

INTRODUCTION: The incorporation of quaternary ammonium polyethylenimine (QPEI) nanoparticles into endodontic sealers induces alterations in their structure and surface properties, which may affect the compatibility with the periapical tissues. This work addressed the behavior of human bone cells exposed to extracts from commercial and QPEI containing AH Plus (DeTrey, Konstanz, Germany) and Pulp Canal Sealer EWT (PCS; Kerr Italia Srl, Salerno, Italy). METHODS: Freshly mixed AH Plus and PCS or containing 2% QPEI (0.3 mL spread over the well bottom of a 24-well plate) were extracted with culture medium (1.5 mL for 24 hours at 37°C) and diluted (1:20-1:5000). Osteoblastic or osteoclastic cells were cultured in the presence of QPEI particles (1%-10%) and were exposed to the extracts from unmodified and QPEI containing sealers. RESULTS: QPEI nanoparticles, at 1% and 2%, did not affect cell behavior. On osteoblastic cells, AH Plus and PCS increased DNA at 1:2500 dilution (levels ≤1:100 were cytotoxic). Alkaline phosphatase activity decreased at dilutions ≤1:500. Comparatively, QPEI containing AH Plus increased DNA at 1:2500 and 1:500 dilutions, and QPEI containing PCS induced ALP activity at 1:2500 and 1:500 dilutions. Regarding osteoclastic cells, DNA increased (AH Plus) or was not affected (PCS) at dilutions up to 1:500 and decreased with more concentrated extracts. Tartrate-resistant acid phosphatase activity decreased with dilutions ≤1:500 for both sealers. QPEI containing sealers presented a similar behavior. The sealers affected some intracellular signaling pathways, and QPEI containing sealers further modulate these mechanisms. CONCLUSIONS: QPEI nanoparticles, at 2%, did not affect cell behavior. However, the incorporation of 2% QPEI particles into AH Plus and PCS modulates the proliferation and differentiation of bone cells, depending on the sealer and the cell type, without increasing the sealers' cytotoxicity.

Long-term dose- and time-dependent effects of endodontic sealers in human in vitro osteoclastogenesis.

INTRODUCTION: This study evaluates the concentration and time-dependent effects of endodontic sealers' extracts (AH Plus [Dentsply DeTrey, Konstanz, Germany], GuttaFlow [Roeko, Colténe/Whaledent, Germany], Tubliseal [Kerr/Sybron, Romulus, MI], Sealapex [Kerr/Sybron, Romulus, MI], and RealSeal [SybronEndo, Orange, CA]) in the differentiation and function of both unstimulated and stimulated osteoclast precursors, simulating, respectively, immature/undifferentiated precursors and cells undergoing osteoclastogenesis. METHODS: The sealers were mixed according to the manufacturers' instructions, freshly extracted with culture medium (1.3 cm(2)/mL, 24 hours, 37°C, 5% CO2/air), and diluted (1:20, 1:100, 1:500, and 1:2500). Human peripheral blood mononuclear cells were used as osteoclast precursor cells. After overnight attachment, peripheral blood mononuclear cell cultures were exposed to the sealers' extracts during 21 days in the absence (unstimulated) or presence (stimulated) of recombinant macrophage colony-stimulating factor and receptor for the activation of nuclear factor-κB ligand. Cultures performed in the absence of the extracts were used as the control. Cultures were characterized for osteoclastic differentiation and function. RESULTS: Extracts caused mostly inhibitory effects on osteoclastic cells, both in unstimulated and stimulated conditions, which were reflected by a decrease in tartrate-resistant acid phosphatase activity, the presence of actin rings, vitronectin and calcitonin receptors, the calcium phosphate resorbing ability, and the expression of osteoclastic genes. Also, the extracts induced alterations in the relative contribution of some intracellular signaling pathways involved in osteoclastogenic events. The sealers differed in the dose- and time-dependent profile. An adaptive cell response was noticed for the inhibitory effects after long-term exposure. CONCLUSIONS: Endodontic sealers affect the osteoclastic differentiation and activity, which is followed by an adaptive cell response. Our results suggest that the deleterious effect in the bone periapical tissues observed with the root canal sealers might involve, at least partially, a direct effect on the osteoclastic cells.

Tissue reactions to a new mineral trioxide aggregate-containing endodontic sealer.

INTRODUCTION: The purpose of this study was to analyze the connective tissue reactions to MTA Fillapex (Ângelus Indústria de Produtos Odontlógicos Ltda, Londrina, Brazil) compared with a zinc oxide-based sealer (EndoFill; Dentsply Indústria e Comérico Ltda, Petrópolis, Brazil) and an epoxy resin-based material (AH Plus; Dentsply DeTrey GmbH, Konstanz, Germany) in Wistar rats. METHODS: Polyethylene tubes containing the test materials and empty polyethylene tubes (control) were implanted in the subcutaneous tissue of 12 rats. Empty tubes were used as a negative control. After 7 and 60 days (n = 6 per period), observations were made for cellular inflammatory components, fibrous condensation, and abscess formation. Comparisons among the groups and between the experimental periods were made using 2-way analysis of variance and the Bonferroni post hoc test (P < .05). RESULTS: At the end of the 7-day experimental period, all sealers scored higher than the control group for the variable lymphocytes, and MTA Fillapex presented lower fiber condensation compared with empty tubes. After 60 days, macrophages and lymphocytes scored significantly higher for MTA Fillapex and EndoFill compared with the negative control, and AH Plus showed similar results related to the empty tubes. Comparing the materials' responses at the end of the 2 evaluated periods, for EndoFill samples the variable neutrophils was detected less after 60 days. Both EndoFill and MTA Fillapex presented increased fiber condensation after 60 days. CONCLUSIONS: Although none of the sealers promoted ideal tissue responses, AH Plus presented the best outcomes. Although MTA Fillapex contains MTA powder, it presented no biocompatibility advantages when compared with AH Plus and EndoFill.

Effect of the root canal final rinse protocols on the debris and smear layer removal and on the push-out strength of an epoxy-based sealer.

The aim of the present study was to evaluate the efficacy of QMiX, SmearClear, and 17% EDTA for the debris and smear layer removal from the root canal and its effects on the push-out bond strength of an epoxy-based sealer by scanning electron microscopy (SEM). Forty extracted human canines (n = 10) were assigned to the following final rinse protocols: G1-distilled water (control), G2-17% EDTA, G3-SmearClear, and G4-QMiX. The specimens were submitted to a SEM analysis to evaluate the presence of debris and smear layer, respectively, in the apical or cervical segments. In sequence, forty extracted human maxillary canines with the root canals instrumented were divided into four groups (n = 10) similar to the SEM analysis study. After the filling with AH Plus, the roots were transversally sectioned to obtain dentinal slices. The specimens were submitted to a push-out bond strength test using an electromechanical testing machine. The statistical analysis for the SEM and push-out bond strength studies were performed using the Kruskal-Wallis and Dunn tests (α = 5%). There was no difference among the G2, G3, and G4 efficacy in removing the debris and smear layer (P > 0.05). The efficacy of these groups was superior to the control group. The push-out bond strength values of G2, G3, and G4 were superior to the control group. The ability to remove the debris and smear layer by SmearClear and QMiX was as effective as the 17% EDTA. The final rinse with these solutions promoted similar push-out bond strength values.

The response of cementoblasts to calcium phosphate resin-based and calcium silicate-based commercial sealers.

AIM: To investigate cell viability and gene expression of cementoblasts (OCCM.30) exposed to extractable components released by resin-based sealers with different chemical composition Hybrid Root Seal (HRS), SimpliSeal (SS), Real Seal (RS) and AH Plus (AH) and by a MTA-based sealers Tech Biosealer Endo (TBE). METHODOLOGY: Discs of all materials were prepared and allowed to set in humid conditions at 37° for 48 h. The discs were then incubated for 72 h at 37 °C to obtain material extracts (1/1) in DMEM. The extracts containing the components released by the sealers were filtered and other dilutions (1/2, 1/4) were prepared from the original solution (1/1). Original and diluted solutions were tested on the cementoblasts. Impedance-based real-time cell analysis (RTCA) was used to evaluate cell viability, quantitative real-time polymerase chain reaction (QRT-PCR) was used to examine the expression of mineralization-related genes (osteocalcin; OCN, Runt-related transcription factor-2; Runx2, collagen type 1; COL I, alkaline phosphatase; ALP). For statistical analysis, one-way analysis of variance (anova) and Tukey's honestly significant difference (HSD) tests were used. RESULTS: TBE (1/2), RS (1/2, 1/4), and HRS (1/2, 1/4) significantly decreased cell viability (P < 0.001). AH (1/2, 1/4) and SS (1/2, 1/4) had similar cell viability to the control at 30 h. All tested materials significantly decreased cell viability when compared to the control group except AH (1/2, 1/4) and SS (1/4) at 90 h. All of the tested sealers reduced COL I mRNA expressions when compared to the control. SS was associated with significant increases in OCN and Runx2 mRNA expressions when compared to the control (P < 0.001). Whereas all of the dilutions of TBE, RS and HRS significantly decreased BSP mRNA expressions (P < 0,001), 1/2 and 1/4 dilutions of SS increased BSP mRNA expression (P < 0,001). Except the 1/4 dilutions of AH and SS, all the sealer dilutions significantly reduced ALP mRNA expression in cementoblasts (P < 0,001). CONCLUSIONS: SimpliSeal and AH Plus resulted in more favourable response to cementoblasts because of their regulation potential on the mineralized tissue-associated protein's mRNA expressions.