To incorporate different concentrations of Al2O9Zr3 (1%, 5%, and 10%) nanoparticles (NP) into the ER adhesive and subsequently assess the impact of this addition on the degree of conversion, µTBS, and antimicrobial efficacy. The current research involved a wide-ranging examination that merged various investigative techniques, including the application of scanning electron microscopy (SEM) for surface characterization of NP coupled with energy-dispersive x-ray spectroscopy (EDX), Fourier-transform infrared (FTIR) spectroscopy, µTBS testing, and microbial analysis. Teeth were divided into four groups based on the application of modified and unmodified three-step ER adhesive primer. Group 1 (0% Al2O9Zr3 NPs) Control, Group 2 (1% Al2O9Zr3 NPs), Group 3 (5% Al2O9Zr3 NPs), and Group 4 (10% Al2O9Zr3 NPs). EDX analysis of Al2O9Zr3 NPs was performed showing elemental distribution in synthesized NPs. Zirconium (Zr), Aluminum (Al), and Oxides (O2). After primer application, an assessment of the survival rate of Streptococcus mutans was completed. The FTIR spectra were analyzed to observe the characteristic peaks indicating the conversion of double bonds, both before and after the curing process, for the adhesive Etch and rinse containing 1,5,10 wt% Al2O9Zr3 NPs. µTBS and failure mode assessment were performed using a Universal Testing Machine (UTM) and stereomicroscope respectively. The µTBS and S.mutans survival rates comparison among different groups was performed using one-way ANOVA and Tukey post hoc (p = .05). Group 4 (10 wt% Al2O9Zr3 NPs + ER adhesive) specimens exhibited the minimum survival of S.mutans (0.11 ± 0.02 CFU/mL). Nonetheless, Group 1 (0 wt% Al2O9Zr3 NPs + ER adhesive) displayed the maximum surviving S.mutans (0.52 ± 0.08 CFU/mL). Moreover, Group 2 (1 wt% Al2O9Zr3 NPs + ER adhesive) (21.22 ± 0.73 MPa) samples displayed highest µTBS. However, the bond strength was weakest in Group 1 (0 wt% Al2O9Zr3 NPs + ER adhesive) (14.13 ± 0.32 MPa) study samples. The etch-and-rinse adhesive exhibited enhanced antibacterial activity and micro-tensile bond strength (µTBS) when 1% Al2O9Zr3 NPs was incorporated, as opposed to the control group. Nevertheless, the incorporation of Al2O9Zr3 NPs led to a decrease in DC. RESEARCH HIGHLIGHTS: 10 wt% Al2O9Zr3 NPs + ER adhesive specimens exhibited the minimum survival of S.mutans. 1 wt% Al2O9Zr3 NPs + ER adhesive samples displayed the most strong composite/CAD bond. The highest DC was observed in Group 1: 0 wt% Al2O9Zr3 NPs + ER adhesive.
Background/purpose: The usage of bioceramic-based root canal sealers has escalated over the years due to their excellent properties. The present study aimed to fabricate a novel algin incorporated bioactive glass 58S calcium-silicate (Bio-G) sealer and characterise its surface microstructure and chemical compositions in comparison to commercially available bioceramic sealers (BioRoot RCS and iRoot SP). Materials and methods: The powder form of experimental Bio-G sealer consisted of synthesised BG 58S particle, calcium silicate, zirconia dioxide, calcium carbonate and alginic acid powder as binder. The liquid composed of 5% calcium chloride solution. Five standardised disc specimens were prepared for each sealer group according to the manufacturer's instructions. Subsequently, sealer disc-specimens were placed in an incubator at 37 °C, 95% relative humidity for 72 h to allow setting prior to testing under scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), Fourier transformed infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Results: Experimental Bio-G sealer revealed irregular micro-sized particles ranging from 0.5 µm to 105 µm aggregated in clusters comparable to those of BioRoot RCS and iRoot SP. EDS microanalysis showed that Bio-G had high content of oxygen, silicon, and calcium, with the presence of aluminium and chloride similar to BioRoot RCS. Meanwhile, the FTIR and XRD findings suggested that all sealers predominantly contained calcium silicate hydrate, calcium carbonate, and zirconium dioxide, while calcium aluminium silicate oxide was detected in Bio-G. Conclusion: The present novel Bio-G sealer demonstrated desirable particle size distribution and acceptable degree of purity. Future studies are warranted to explore its properties and clinical application.
The currently available bioceramic-based sealers still demonstrate low bond strength with a poor seal in root canal despite desirable biological properties. Hence, the present study aimed to determine the dislodgment resistance, adhesive pattern, and dentinal tubule penetration of a novel experimental algin-incorporated bioactive glass 58S calcium silicate-based (Bio-G) sealer and compared it with commercialised bioceramic-based sealers. A total of 112 lower premolars were instrumented to size 30. Four groups (n = 16) were assigned for the dislodgment resistance test: control, gutta-percha + Bio-G, gutta-percha + BioRoot RCS, and gutta-percha + iRoot SP, with exclusion of the control group in adhesive pattern and dentinal tubule penetration tests. Obturation was done, and teeth were placed in an incubator to allow sealer setting. For the dentinal tubule penetration test, sealers were mixed with 0.1% of rhodamine B dye. Subsequently, teeth were cut into a 1 mm-thick cross section at 5 mm and 10 mm levels from the root apex, respectively. Push-out bond strength, adhesive pattern, and dentinal tubule penetration tests were performed. Bio-G showed the highest mean push-out bond strength (p < 0.05), while iRoot SP showed the greatest sealer penetration (p < 0.05). Bio-G demonstrated more favourable adhesive patterns. No significant association was noted between dislodgment resistance and dentinal tubule penetration (p > 0.05).
PURPOSE: This study sought to investigate the acceptance rate and associated factors of COVID-19 vaccines among dentists and dental students in seven countries. MATERIAL AND METHODS: A structured questionnaire prepared and guided by the report of the SAGE Working Group on Vaccine Hesitancy was distributed among groups of dentists and dental students in seven countries across four continents. RESULTS: A total of 1527 subjects (850 dentists and 677 dental students) participated in this survey. Although 72.5% of the respondents reported their intention to accept COVID-19 vaccines (dentists: 74.4%, dental students: 70.2%), there was a significant difference in agreement between dentists/dental students across countries; generally, respondents in upper-middle-, and high-income countries (UM-HICs) showed significantly higher acceptance rates compared to those in low- and lower-middle income countries (L-LMICs). Potential predictors of higher vaccine acceptance included being a dentist, being free of comorbidity, being well-informed about COVID-19 vaccines, having better knowledge about COVID-19 complications, having anxiety about COVID-19 infection, having no concerns about the side effects of the produced vaccines and being a resident of an UM-HIC. CONCLUSION: The results of our survey indicate a relatively good acceptance rate of COVID-19 among the surveyed dentists and dental students. However, dentists and dental students in L-LMICs showed significantly lower vaccine acceptance rates and trust in COVID-19 vaccines compared to their counterparts in UM-HICs. Our results provide important information to policymakers, highlighting the need for implementation of country-specific vaccine promotion strategies, with special focus on L-LMICs.
Aim: To investigate and compare the cell cytotoxicity, proliferation, cell attachment, and morphology of human fetal osteoblasts (hFOB) cells of coated samples (titanium nanocopper (Ti Cu), titanium nanohydroxyapatite (Ti HA) and titanium nanocopper ion doped hydroxyapatite (Ti Cu/HA) and uncoated samples (Ti) in order to assess the suitability of these surface modifications on Ti-6Al-7Nb for dental implant application. Materials and Methods: The cytotoxicity was studied by examining the hFOB cell response by MTT assessment. The cell morphology was evaluated by inverted microscopy and observed under scanning electronic microscopy (SEM). Results: MTT assay results displayed that the Cu content on the surface of Ti-6Al-7Nb alloys did not produce any cytotoxic effect on cell viability. The cell viability rate in all samples ranges from 97% to 126%, indicating that hFOB cells grew at a high proliferation rate. However, no significant differences in cell viability were observed between Ti and Ti Cu and between Ti HA and Ti Cu/HA groups. Microscopic examination demonstrated no difference in the cell morphology of hFOB among all samples. In addition, SEM observation indicated favorable adhesion and spreading of the cells on the coated and uncoated samples. Conclusions: The surface modification of Ti-6Al-7Nb alloy with Cu, HA, and Cu/HA exhibits good cell biocompatibility, and the Cu has no influence on the cell proliferation and differentiation of hFOB.
Nanoparticles , Titanium , Humans , Copper , Durapatite , Titanium/pharmacology
One of the foremost missions in restorative dentistry is to discover a suitable material that can substitute lost and damaged tooth structure. To this date, most of the restorative materials utilized in dentistry are bio-inert. It is predicted that the addition of nano-HA-SiO2 to GIC matrix could produce a material with better ion-exchange between the restorative material and natural teeth. Therefore, the aim of the current study was to synthesize and investigate the transfer of specific elements (calcium, phosphorus, fluoride, silica, strontium, and alumina) between nano-hydroxyapatite-silica added GIC (nano-HA-SiO2-GIC) and human enamel and dentine. The novel nano-hydroxyapatite-silica (nano-HA-SiO2) was synthesized using one-pot sol-gel method and added to cGIC. Semi-quantitative energy dispersive X-ray (EDX) analysis was carried out to determine the elemental distribution of fluorine, silicon, phosphorus, calcium, strontium, and aluminum. Semi-quantitative energy dispersive X-ray (EDX) analysis was performed by collecting line-scans and dot-scans. The results of the current study seem to confirm the ionic exchange between nano-HA-SiO2-GIC and natural teeth, leading to the conclusion that increased remineralization may be possible with nano-HA-SiO2-GIC as compared to cGIC (Fuji IX).
Objectives: Even though several effective vaccines are available to combat the COVID-19 pandemic, wide disparities in vaccine distribution, and vaccine acceptance rates between high- and low-income countries appear to be major threats toward achieving population immunity. Our global descriptive study aims to inform policymakers on factors affecting COVID-19 vaccine acceptance among healthcare workers (HCWs) in 12 countries, based on income index. We also looked for possible predictors of vaccine acceptance among the study sample. Methods: A structured questionnaire prepared after consultation with experts in the field and guided by the "Report of the SAGE working group on vaccine hesitancy" was administered among 2,953 HCWs. Upon obtaining informed consent, apart from demographic information, we collected information on trust in vaccines and health authorities, and agreement to accept a COVID-19 vaccine. Results: Although 69% of the participants agreed to accept a vaccine, there was high heterogeneity in agreement between HCWs in low and lower-middle income countries (L-LMICs) and upper-middle- and high-income countries (UM-HICs), with acceptance rates of 62 and 75%, respectively. Potential predictors of vaccine acceptance included being male, 50 years of age or older, resident of an UM-HIC, updating self about COVID-19 vaccines, greater disease severity perception, greater anxiety of contracting COVID-19 and concern about side effects of vaccines. Conclusions: COVID-19 vaccine acceptance among HCWs in L-LMICs was considerably low as compared to those from UM-HICs. The lowest vaccine acceptance rates were among HCWs from the African continent. This underlines the need for the implementation of country-specific vaccine promotion strategies, with special focus on increasing vaccine supply in L-LMICs.
COVID-19 Vaccines , COVID-19 , COVID-19/prevention & control , Cross-Sectional Studies , Health Personnel , Humans , Male , Pandemics , SARS-CoV-2 , Surveys and Questionnaires
This study aimed to investigate the effects of nanohydroxyapatite-silica-glass ionomer cement (nanoHA-silica-GIC) on the differentiation of dental pulp stem cells (DPSCs) into odontogenic lineage. DPSCs were cultured in complete Minimum Essential Medium Eagle-Alpha Modification (α-MEM) with or without nanoHA-silica-GIC extract and conventional glass ionomer cement (cGIC) extract. Odontogenic differentiation of DPSCs was evaluated by real-time reverse transcription polymerase chain reaction (rRT-PCR) for odontogenic markers: dentin sialophosphoprotein (DSPP), dentin matrix protein 1 (DMP1), osteocalcin (OCN), osteopontin (OPN), alkaline phosphatase (ALP), collagen type I (COL1A1), and runt-related transcription factor 2 (RUNX2) on day 1, 7, 10, 14, and 21, which were normalized to the house keeping gene glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Untreated DPSCs were used as a control throughout the study. The expressions of DSPP and DMP1 were higher on days 7 and 10, that of OCN on day 10, those of OPN and ALP on day 14, and that of RUNX2 on day 1; COL1A1 exhibited a time-dependent increase from day 7 to day 14. Despite the above time-dependent variations, the expressions were comparable at a concentration of 6.25 mg/mL between the nanoHA-silica-GIC and cGIC groups. This offers empirical support that nanoHA-silica-GIC plays a role in the odontogenic differentiation of DPSCs.
The aim of this article is to provide a brief insight regarding the recent studies and their recommendations related to the modifications to glass ionomer cement (GIC) powder in order to improve their properties. An electronic search of publications was made from the year 2000 to 2018. The databases included in the current study were EBSCOhost, PubMed, and ScienceDirect. The inclusion criteria for the current study include publication with abstract or full-text articles, original research, reviews or systematic reviews, in vitro, and in vivo studies that were written in English language. Among these only articles published in peer-reviewed journals were included. Articles published in other languages, with no available abstract and related to other nondentistry fields, were excluded. A detailed review of the recent materials used as a filler phase in GIC powder has revealed that not all modifications produce beneficial results. Recent work has demonstrated that modification of GIC powder with nano-particles has many beneficial effects on the properties of the material. This is due to the increase in surface area and surface energy, along with better particle distribution of the nano-particle. Therefore, more focus should be given on nano-particle having greater chemical affinity for GIC matrix as well as the tooth structure that will enhance the physicochemical properties of GIC.
BACKGROUND: Despite their lower strength, glass ionomer cements (GICs) are widely used as restorative materials because of their anti-cariogenic properties, direct adhesion to tooth structure and good biocompatibility. Recently, the addition of nano-hydroxyapatite (nano-HA)-silica to conventional GIC (cGIC) has been shown to improve the strength of cGIC. However, the biocompatibility and cell attachment properties of this material are unknown. AIMS: This study aims to evaluate and compare the cytotoxicity and cell attachment properties of cGIC and nano-HA-silica-GIC on dental pulp stem cells (DPSCs). METHODS AND MATERIALS: Material extracts of nano-HA-silica-GIC and cGIC were prepared into seven serial dilutions and applied to 96 well plates seeded with DPSCs. After 72 h, the cell viability was determined using MTT assay. The DPSCs cell attachment properties were examined under scanning electron microscope (SEM) after 24 and 72 h. Kruskal-Wallis test was used to analyse the data for MTT assay (P < 0.05). SEM images of cell attachment properties were also described. RESULTS: Nano-HA-silica-GIC and cGIC was shown to be slight to non-cytotoxic at all concentrations, except 200 mg/ml. Moderate cytotoxicity has been observed at 200 mg/ml concentration where nano-HA-silica-GIC and cGIC revealed cell viability values of 44.38 and 42.15%, respectively. Nano-HA-silica-GIC demonstrated better cell viability values than cGIC at all concentrations except for 6.25 and 12.5 mg/ml. Nevertheless, the results were not statistically significant (P > 0.05). SEM examination revealed the increasing numbers of DPSCs attached to both groups with prominent filopodia, especially after 72 h. CONCLUSIONS: Nano-HA-silica-GIC exhibited good biocompatibility which is comparable to cGIC and favoured the attachment of DPSCs.
OBJECTIVE: The aim of this review was to provide an insight about the factors affecting the properties of glass ionomer cements and provides a review regarding studies that are related to modification of glass ionomer cements to improve their properties, particularly on physical-mechanical and antimicrobial activity. METHODS: PubMed and Science Direct were searched for papers published between the years 1974 and 2018. The search was restricted to articles written in English related to modification of glass ionomer cements. Only articles published in peer-reviewed journals were included. The search included literature reviews, in vitro, and in vivo studies. Articles written in other languages, without available abstracts and those related to other field were excluded. About 198 peer-review articles in the English language were reviewed. CONCLUSION: Based on the finding, most of the modification has improved physical-mechanical properties of glass ionomer cements. Recently, researchers have attempted to improve their antimicrobial properties. However, the attempts were reported to compromise the physical-mechanical properties of modified glass ionomer cements. CLINICAL SIGNIFICANCE: As the modification of glass ionomer cement with different material improved the physical-mechanical and antimicrobial properties, it could be used as restorative material for wider application in dentistry.
Anti-Infective Agents , Glass Ionomer Cements , Materials Testing
OBJECTIVES: This study aimed to evaluate the chemical and biological properties of fast-set white mineral trioxide aggregate (FS WMTA), which was WMTA combined with calcium chloride dihydrate (CaCl2·2H2O), compared to that of WMTA. MATERIALS AND METHODS: Surface morphology, elemental, and phase analysis were examined using scanning electron microscope (SEM), energy dispersive X-ray microanalysis (EDX), and X-ray diffraction (XRD), respectively. The cytotoxicity and cell attachment properties were evaluated on human periodontal ligament fibroblasts (HPLFs) using methyl-thiazol-diphenyltetrazolium (MTT) assay and under SEM after 24 and 72 hours, respectively. RESULTS: Results showed that the addition of CaCl2·2H2O to WMTA affected the surface morphology and chemical composition. Although FS WMTA exhibited a non-cytotoxic profile, the cell viability values of this combination were lesser than WMTA, and the difference was significant in 7 out of 10 concentrations at the 2 time intervals (p < 0.05). HPLFs adhered over the surface of WMTA and at the interface, after 24 hours of incubation. After 72 hours, there were increased numbers of HPLFs with prominent cytoplasmic processes. Similar findings were observed with FS WMTA, but the cells were not as confluent as with WMTA. CONCLUSIONS: The addition of CaCl2·2H2O to WMTA affected its chemical properties. The favorable biological profile of FS WMTA towards HPLFs may have a potential impact on its clinical application for repair of perforation defects.
INTRODUCTION: Glass Ionomer Cements (GIC) are among the most popular restorative materials, but their use in dentistry is limited due to their physical properties. The hardness of GIC was improved by incorporation of nano-hydroxyapatite-silica into GIC, to expand its applicability. AIM: To evaluate the cytotoxic effects of nano-hydroxyapatite-silica incorporated glass ionomer cement (HA-SiO2-GIC) on human Dental Pulp Stem Cells (DPSC) and compare it with conventional GIC and resin modified GIC. MATERIALS AND METHODS: Material extracts of Fuji IX, Fuji II LC and HA-SiO2-GIC were prepared into seven serial concentrations and applied to 96-well-plates seeded with DPSC. The 96-well-plates were incubated for 24 and 72 hours. The morphology of DPSC was observed under the inverted phase contrast microscope, and the cell viability was determined using MTT assay at both time intervals. Kruskal-Wallis test was performed for statistical analysis. RESULTS: At maximum concentration, DPSC appeared fewer in number, but the normal spindle morphology was maintained in all groups except for Fuji II LC. At lower concentrations, DPSC appeared normal and more confluent in all groups. The cytotoxic effects of all groups were dose dependent. Fuji IX demonstrated the lowest cytotoxicity, followed by HA-SiO2-GIC. Fuji II LC demonstrated the highest cytotoxicity. The difference was significant between all groups at 200 mg/ml concentration (p<0.05). At concentration <100 mg/ml, cytotoxicity of HA-SiO2-GIC was comparable to that of Fuji IX and lower than that of Fuji II LC. CONCLUSION: HA-SiO2-GIC showed a favourable cytotoxicity response and thus holds promise as a future potential restorative material in clinical dentistry.
The odontogenic and osteogenic potential of dental pulp stem cells (DPSCs) and stem cells from human exfoliated deciduous tooth (SHED) have been shown clearly by various in vitro and in vivo studies. The findings are promising and demonstrated that dental tissue engineering can give a new hope to the individuals suffering from tooth loss and dental diseases. The evaluation of odontogenic and osteogenic differentiation of DPSCs and SHED is commonly carried out by an illustration of the expression of varied related markers. In this review, few commonly used markers such as alkaline phosphatase (ALP), collagen type 1 (Col I), dentin matrix acid phosphoprotein 1 (DMP1), dentin sialophosphoprotein (DSPP), matrix extracellular phosphoglycoprotein (MEPE), osteocalcin (OCN), and osteopontin (OPN). DSPP, DMP1, and MEPE (odontogenic markers), which play an important role during early odontoblastic differentiation and late dentin mineralization, have been highlighted. Osteoblastic proliferation and early/late osteoblastic differentiation can be assessed by estimating the expression of Col I, ALP, OCN and OPN. Despite that, till date, there is no marker which could demonstrate for certain, the differentiation of human DPSCs and SHED towards the odontogenic and osteogenic lineage. This review suggests that SHED are noticeably different from DPSCs and exhibited higher capacity for osteogenic differentiation compared to DPSCs. On the other hand, different expression levels are shown by SHED and DPSCs with regards to the osteoblast markers for osteoblastic differentiation, where, SHED expressed higher levels of ALP, Col I and OCN compared to DPSCs.
Biomarkers/metabolism , Dental Pulp/cytology , Odontogenesis , Osteogenesis , Stem Cells/cytology , Tooth, Deciduous/cytology , Humans
White Portland cement (WPC) has generated research interests in the field of endodontics. This study compared between the properties of two formulations of white Portland cement (WPC) of different origin (Malaysia [MA] and Egypt [EG]). WPCs with and without calcium chloride dihydrate were prepared. Scanning electron microscope (SEM), energy dispersive X-ray micro-analysis, and X-ray diffraction were used for surface morphology evaluation, elemental, and phase analysis, respectively. After the preparation of optimized serial dilutions, the cytotoxicity was evaluated on human periodontal ligament fibroblasts (HPLFs) and dental pulp stem cells (DPSCs) using methyl-thiazol-diphenyltetrazolium assay after 24 and 72 h. Cell attachment properties were examined under SEM after 24 and 72 h. Results showed that the surface morphology and chemical composition of both formulations demonstrated detectable variations. The cytotoxicity evaluation showed different cellular responses of HPLFs compared to DSPCs. Both formulations favored the viability of HPLFs. However, the fast set formulations demonstrated severe cytotoxicity on DPSCs. Significant differences between EGWPC and MAWPC were identified (p < 0.05). The cell attachment properties were favorable; however, HPLFs attached and spread over the samples better than DPSCs. In conclusion, WPC of different origin may show differences in chemical and biological properties. The addition of CaCl2 ·2H2 O to WPC can affect its properties. Human cell types may react differently towards different formulations of WPCs. SCANNING 38:303-316, 2016. © 2015 Wiley Periodicals, Inc.
Calcium Compounds , Root Canal Filling Materials , Silicates , Humans , Materials Testing , X-Ray Diffraction
OBJECTIVES: To compare the cytotoxicity of conventional GIC and Resin Modified GIC (RMGIC) polymerized at 2 different times on stem cells from human exfoliated deciduous teeth (SHED). STUDY DESIGN: The conventional GIC (Fuji IX GP Extra) and RMGIC (Fuji II LC) were mixed and incubated in a prepared Dublecco's Modified Eagle Medium (DMEM) for seven days. After seeding the characterized SHED for 24 hrs, six replicates of seven serially diluted extracts of each group were added and incubated for 72 hrs. MTT test was used for cytotoxicity evaluation and the data were analysed using Kruskal-Wallis followed by Mann-Whitney test, with the statistical significance set at P<0.05. RESULTS: The half maximal inhibitory concentration (IC50) was found at 45.0 mg/ml, 45.0 mg/ml and 31.25 mg/ml for Fuji IX, Fuji II LC (40s) and Fuji II LC (20s), respectively. Significantly different cytotoxic effects were found between Fuji II LC polymerized at 20 secs and 40 secs, and between Fuji IX and Fuji II LC (20s) (P<0.05), and these were observed in all concentrations except for 50 mg/ml. CONCLUSIONS: RMGIC polymerized at 20 secs exhibited the least favorable cell viability among all groups. Nevertheless, the cell viability was comparable to conventional GICs when the manufacturer's recommended time was doubled (40 secs).
Glass Ionomer Cements/toxicity , Resin Cements/toxicity , Stem Cells/drug effects , Tooth, Deciduous/cytology , Cell Culture Techniques , Cell Survival/drug effects , Coloring Agents , Humans , Materials Testing , Polymerization , Resins, Synthetic/toxicity , Tetrazolium Salts , Thiazoles , Time Factors , Tooth, Deciduous/drug effects
INTRODUCTION: The attachment and spreading of mammalian cells on endodontic biomaterials are an area of active research. The purpose of this review is to discuss the cell attachment properties of Portland cement (PC)-based materials by using scanning electron microscope (SEM). In addition, methodological aspects and technical challenges are discussed. METHODS: A PubMed electronic search was conducted by using appropriate key words to identify the available investigations on the cell attachment properties of PC-based endodontic materials. After retrieving the full text of related articles, the cross citations were also identified. RESULTS: A total of 23 articles published between January 1993 and October 2013 were identified. This review summarizes the cell attachment properties of commercial and experimental PC-based materials on different cell cultures by using SEM. Methodological procedures, technical challenges, and relevance of SEM in determining the biological profile of PC-based materials are discussed. CONCLUSIONS: SEM observations demonstrate that commercial MTA formulations show favorable cell attachment properties, which is consistent with their successful clinical outcomes. The favorable cell attachment properties of PC and its modified formulations support its potential use as a substitute for mineral trioxide aggregate. However, researchers should carefully select cell types for their SEM investigations that would be in contact with the proposed PC-based combinations in the clinical situation. Despite being a technical challenge, SEM provides useful information on the cell attachment properties of PC-based materials; however, other assays for cell proliferation and viability are essential to come up with an accurate in vitro biological profile of any given PC-based formulation.
Aluminum Compounds/chemistry , Biocompatible Materials/chemistry , Calcium Compounds/chemistry , Cell Adhesion , Oxides/chemistry , Root Canal Filling Materials/chemistry , Silicates/chemistry , Cell Adhesion/physiology , Cell Movement/physiology , Cells, Cultured/physiology , Drug Combinations , Humans , Materials Testing/methods , Microscopy, Electron, Scanning , Surface Properties
AIM: To evaluate and compare the microleakage of various restorative materials used as coronal barriers between endodontic appointments. MATERIALS AND METHODS: Eighty extracted human permanent posterior teeth were prepared for standardized access cavities with dimensions of 4 × 4 × 4 mm. The teeth were then randomly divided into four groups; Kalzinol, Caviton, GC Fuji IX and GC Fuji II LC. After incubation, the samples were immersed in 2% methylene blue for 7 days. The depth of penetration was measured using a digital macroscope after longitudinal sectioning of each tooth. Kruskal-Wallis (p < 0.05) and multiple Mann-Whitney test with Bonferroni correction (p < 0.008) were used for data analysis. RESULTS: The degree of microleakage varied at the material/ tooth interface among the test materials, and the difference was statistically significant (p < 0.05). GC Fuji II LC group showed the least median microleakage value (0.8105 ± 0.305), followed by Caviton (1.1885 ± 0.396), GC Fuji IX (3.3985 ± 0.305) and Kalzinol (4.161 ± 0.853). CONCLUSION: Within the limitations of this study, GC Fuji II LC exhibited the best marginal seal, and has the potential to be used as a suitable coronal barrier between endodontic appointments. CLINICAL SIGNIFICANCE: Given the prime importance that dental practitioners should thoroughly restore any tooth with a suitable coronal barrier between endodontic appointments, this study shows that Fuji II LC has the ability to maintain a hermetic seal for 7 days.
Dental Bonding , Dental Leakage/classification , Root Canal Filling Materials/chemistry , Root Canal Therapy/methods , Acrylic Resins/chemistry , Calcium Sulfate/chemistry , Coloring Agents , Dental Cements/chemistry , Dental Pulp Cavity/ultrastructure , Dentin/ultrastructure , Drug Combinations , Eugenol/chemistry , Formaldehyde/chemistry , Glass Ionomer Cements/chemistry , Humans , Materials Testing , Methylene Blue , Resin Cements/chemistry , Resins, Synthetic/chemistry , Root Canal Preparation/methods , Smear Layer , Surface Properties , Time Factors , Vinyl Compounds/chemistry , Zinc Oxide/chemistry
Complete debridement and disinfection of the root canal system are fundamental requirements for successful endodontic treatment. Despite the morphological challenges of the internal root anatomy, root canal irrigants play an important role in the optimization of the root canal preparation, which is essentially a chemo-mechanical procedure. Enterococcus faecalis is one of the most resistant microorganisms that dominants the microbial ecosystem of persistent periradicular lesions in retreatment cases. For that reason, many in vitro and in vivo studies evaluated and compared the antibacterial activity of sodium hypochlorite and chlorhexidine at varying concentrations using different experimental models against this microorganism. However, many controversies with regard to the ideal irrigant and concentration do in fact exist. Hence, this review aims to discuss the antibacterial activity of these two main root canal irrigants against Enterococcus faecalis using the agar diffusion and direct contact methods and the possible modulating factors responsible for inconsistent findings among different studies. In addition, the disinfection potential of both chemical agents on gutta percha and Resilon cones are also discussed. The source of this review was conducted through an electronic literature search using PubMed database from December 1997 until December 2011, which analyze the related laboratory investigations of both irrigants, published in major endodontic journals.
Aim: To measure the fracture resistance of over-flared roots filled with a variety of materials (gutta-percha-nano HA, resilon-epiphany, composite and mineral trioxide aggregate - MTA) using the Instron machine test and micro-computed tomography (Micro CT) Scan. In addition, scanning electron microscopy (SEM) images were used to illustrate the type of fracture patternsof the specimens. Methods: One hundred and twenty extracted human mandibular single rooted premolars were selected. A total of 105 out of the selected teeth were prepared to the working length and over-flared, leaving the apical 5 mm undisturbed. Fifteen samples had no treatment and were used as a positive control group (Group +ve). The 105 test teeth were further divided into 7 groups of 15 samples each. One of the 7 groups was designated as negative control (Group -ve) where teeth were over prepared and left without obturation.Remaining groups were filled with gutta-percha-nanoHA (Group1), gutta-percha-nano HA+composite (Group 2), gutta-percha-nano HA+MTA (Group 3), resilon-epiphany (Group 4),resilon-epiphany+composite (Group 5), and resilon-epiphany+MTA (Group 6). Fracture resistance of all samples was measured using the Instron testing machine. Three samples from each group had the depth of their fracture line measured by Micro CT Scan, and 2 samples from each group had their fracture pattern illustrated using SEM. Results: The highest fracture resistance was observed in Group +ve, followed by Groups 3, 6, 5, 2, 4, 1, and Group -ve, with values (in N) of: 1598 (641.0), 1190.5(424.2), 1164.7 (489.4), 821.2 (220.9), 683.4(179),658.4 (211.3), 658.4 (99.0), 158.3(49.3), respectively. Statistical analysis for root fracture resistance showed highly significant difference between all groups with p value < 001.Conclusions: Micro CT Scan and SEM analysis indicated the ability of MTA to withstand vertical force.
Microscopy, Electron, Scanning , Root Canal Filling Materials
