Biomineralization potential and biological properties of a new tantalum oxide (Ta2O5)-containing calcium silicate cement.

OBJECTIVE: The present study evaluated the biological effects and biomineralization potential of a new tantalum oxide (Ta2O5)-containing material designed for vital pulp therapy or perforation repair (NeoMTA 2), compared to NeoMTA Plus and Bio-C Repair. MATERIAL AND METHODS: Human dental pulp stem cells (hDPSCs) were exposed to different eluates from NeoMTA Plus, NeoMTA 2, and Bio-C Repair. Ion release from each material was determined using inductively coupled plasma-optical emission spectrometry (ICP-MS). The biological experiments performed were MTT assays, apoptosis/necrosis assays, adhesion assays, migration assays, morphology evaluation, and reactive oxygen species (ROS) production analysis. Biomineralization was assessed by Alizarin red S staining. Finally, osteo/odontogenic gene expression was determined by real-time quantitative reverse-transcriptase polymerase chain reaction (RT-qPCR). Data were analyzed using one-way ANOVA followed by Tukey's multiple comparison test. RESULTS: NeoMTA 2 displayed a significantly higher calcium release compared to the other materials (p < 0.05). When hDPSCs were cultured in presence of the different material eluates, all groups exhibited similar hDPSC viability and migration rates when compared to untreated cells. Substantial cell attachment and spreading were observed in all materials' surfaces, without significant differences. hDPSCs treated with NeoMTA 2 displayed an upregulation of ALP, Col1A1, RUNX2 (p < 0.001), ON, and DSPP genes (p < 0.05), and showed the highest mineralization potential compared to other groups (p < 0.001). Finally, the more concentrated eluates from these materials, specially NeoMTA Plus and NeoMTA 2, promoted higher ROS production in hDPSCs compared to Bio-C Repair and control cells (p < 0.001), although these ROS levels did not result in increased cell death. CONCLUSIONS: The new tantalum oxide (Ta2O5)-containing material shows an adequate cytocompatibility and the ability to promote biomineralization without using chemical osteogenic inducers, showing great potential as a new material for vital pulp therapy. CLINICAL RELEVANCE: NeoMTA 2 seems to be a promising material for vital pulp therapy. Further studies considering its biocompatibility and biomineralization potential are necessary.

Microstructural composition, ion release, and bioactive potential of new premixed calcium silicate-based endodontic sealers indicated for warm vertical compaction technique.

OBJECTIVE: The aim of this study was to evaluate the microstructural composition, ion release, cytocompatibility, and mineralization potential of Bio-C Sealer ION+ (BCI) and EndoSequence BC Sealer HiFlow (BCHiF), compared with AH Plus (AHP), in contact with human periodontal ligament cells (hPDLCs). MATERIALS AND METHODS: The sealers' ionic composition and release were assessed using energy-dispersive spectroscopy (EDS) and inductively coupled plasma mass spectrometry (ICP-MS), respectively. For the biological assays, hPDLCs were isolated from third molars, and sealer extracts were prepared (undiluted, 1:2, and 1:4 ratios). An MTT assay, wound-healing assay, and cell morphology and adhesion analysis were performed. Activity-related gene expression was determined using RT-qPCR, and mineralization potential was assessed using Alizarin Red staining (ARS). Statistical analyses were performed using one-way ANOVA and Tukey's post hoc test (α < 0.05). RESULTS: The three sealers exhibited variable levels of silicon, calcium, zirconium, and tungsten release and in their composition. Both BCI and BCHiF groups showed positive results in cytocompatibility assays, unlike AHP. The BCHiF group showed an upregulation of CAP (p < 0.01), CEMP1, ALP, and RUNX2 (p < 0.001) compared with the negative control, while the BCI group showed an upregulation of CEMP1 (p < 0.01), CAP, and RUNX2 (p < 0.001). Both groups also exhibited a greater mineralization potential than the negative and positive controls (p < 0.001). CONCLUSIONS: The calcium silicate-based sealers considered in the present in vitro study exhibited a high calcium ion release, adequate cytocompatibility, upregulated osteo/cementogenic gene expression, and increased mineralized nodule formation in contact with hPDLCs. CLINICAL RELEVANCE: From a biological perspective, BCI and BCHiF could be clinically suitable for root canal filling.

Chemical composition and bioactivity potential of the new Endosequence BC Sealer formulation HiFlow.

AIM: To evaluate in a laboratory setting the effects of Endosequence BC Sealer HiFlow (Brasseler USA, Savannah, GA, USA), a novel calcium silicate-based sealer developed for use in warm canal filling techniques, on human periodontal ligament stem cells (hPDLSCs). METHODOLOGY: Eluates of EndoSequence BC Sealer HiFlow (BCHiF) (Brasseler USA), EndoSequence BC Sealer (BCS) (Brasseler USA) and AH Plus (AHP) (Dentsply DeTrey GmbH, Konstanz, Germany) were placed in contact with hPDLSCs. The characterization of the chemical elements of the root canal sealers was assessed using scanning electron microscopy and energy-dispersive X-ray analysis (SEM-EDX). Inductively coupled plasma-mass spectrometry (ICP-MS) was used to determine the ion release of the sealers. MTT assay and wound healing techniques were used to determine cell viability and migration, respectively. Cell morphology and cell attachment were assessed using a direct contact technique of hPDLSCs onto the surface of the sealers and analysed by SEM. The bioactivity potential was carried out with the Alizarin Red and qPCR testing methods. The statistical differences were evaluated using one-way anova and Tukey's test (P < 0.05). RESULTS: ICP-MS and EDX revealed significantly more zirconium in BCHiF than BCS (P < 0.05), whereas BCS had slightly higher levels of Ca2+ than BCHiF (P < 0.05). The cell viability assay revealed no relevant differences between BCS and BCHiF when compared with the control group (P > 0.05). Both BCS and BCHiF had similar rates of cell migration to the control group at 24 and 48 h. Cell morphology and adhesion capacity were also similar for BCS and BCHiF groups, whilst the AHP group was associated with reduced adhesion capacity. The Alizarin Red assay revealed a significant difference between the BCS and the control group (P < 0.001), as well as for the BCHiF group (P < 0.001). Finally, BCS and BCHiF promoted overexpression of osteo/cementogenic genes. CONCLUSIONS: In general, EndoSequence BC Sealer HiFlow possesses suitable biological properties to be safely used as a root canal filling material and promote increased expression of oste/cementogenic genes by hPDLSCs.

Cytocompatibility, bioactivity potential, and ion release of three premixed calcium silicate-based sealers.

OBJECTIVE: Compositional modifications may alter the biological and physicochemical characteristics of calcium silicate-based sealers (CSBS) and, ultimately, their bioactivity. The main objective of this study was to evaluate the biological properties of three CSBS: EndoSequence BC Sealer, Ceraseal, and Endoseal mineral trioxide aggregate. MATERIALS AND METHODS: Human periodontal ligament stem cells (hPDLSCs) were exposed to several eluates of CSBS. The ion release profile and pH were determined, and metabolic activity and cell migration were assessed using the MTT and wound healing assays. hPDLSCs were cultured in direct contact with the surface of each material, and cell morphology and attachment were analyzed by scanning electron microscopy (SEM). Bioactivity potential was assessed by RT-qPCR and mineralization assays. Statistical differences between biomaterials were assessed using one- or two-way ANOVA (α < 0.05). RESULTS: All materials showed an alkaline pH, although Endoseal exhibited a significantly higher pH compared with the other CSBS (p < 0.05). Ceraseal released significantly more Ca2+ (p < 0.05) than EndoSequence BC Sealer and Endoseal. Interestingly, Endoseal induced a significant reduction in cell viability and cell migration compared with the control (p < 0.001). Moreover, SEM showed abundant cells adhering to EndoSequence BC Sealer and Ceraseal surfaces, whereas very few round cells were detected on the surface of Endoseal. Finally, Ceraseal and EndoSequence induced ALP, CAP, and CEMP-1 expression and a significantly higher mineralization capacity than Endoseal (***p < 0.001). CONCLUSIONS: The eluates from EndoSequence BC Sealer and Ceraseal displayed higher cell viability, cell attachment, cell migration rates, and ion release rates than Endoseal. Ceraseal and EndoSequence BC Sealer exhibited significantly more gene expression and mineralization capacity than Endoseal. CLINICAL RELEVANCE: The results obtained in the present work suggest that EndoSequence BC Sealer and Ceraseal possess biological properties that make them suitable materials for root canal treatment.

Prevalence of Apical Periodontitis in patients with Multiple Myeloma.

BACKGROUND: Aim Previous reports have been analyzed the prevalence/association of apical periodontitis (AP) with systemic diseases. The present study aims to analyze the prevalence of healthy/diseased periapex and endodontic treatments in patients with Multiple Myeloma (MM) and compare the results with those of control subjects. MATERIAL AND METHODS: Methodology Panoramic radiographs of 50 individuals with MM were evaluated and compared with 50 controls that were sex and age matched exactly with the diseased group. Radiographic analysis was performed by 2 two experienced endodontists under standardized conditions. The periapical status (presence or not of AP) was assessed using the periapical index (PAI). Data included systemic health, technical quality of root fillings, total number of teeth, quality of restoration, and periapical status. Statistical evaluation of differences between groups included used chi-squared tests and Fisher's exact tests. RESULTS: The prevalence of root canal-treated teeth was 10.11% in the MM group and 12.05% in the control group (p=0.90). The average root canal-treated teeth in the test group was 2,34 and 2.48 in the control group, where the difference was statistically significant (p=0.05). AP in 1 or more teeth was found in 86 % and in 78% of the patients in the MM and the control groups, respectively. When analyzed by subject, there was no statistically significant difference in the prevalence of AP (p>0.72). Similarly there was also no statistically significant difference in the prevalence of PA (p=0.85), when analyzed by tooth, AP was found in 63.2% and 62.9% in MM and control groups. CONCLUSIONS: The presence of AP and endodontic treatment was not significantly different in individuals with MM compared with control subjects. Future studies are needed to elucidate and confirm the association between MM and AP.

Canal shaping with a reciprocating system is easy to learn.

AIM: To assess progressive learning of root canal shaping in order to define the number of simulated canals in resin blocks needed to reach a level of learning beyond which no further improvement in performance is observed. METHODOLOGY: A total of 216 simulated canals in resin blocks were instrumented by 18 operators without experience in Endodontics and by 18 Endodontists. The R25 file of the Reciproc system (VDW, Munich, Germany) was used to prepare the canals. The blocks were photographed before and after instrumentation. An analysis was made of the variations in the dimensions of the canals at 6 locations and of the instrumentation time. A Student's t-test was used to analyse the data (P < 0.05). RESULTS: The group without experience were associated with significant differences in instrumentation time between the first canal and the subsequent canals (P < 0.05) but differences in canal dimensions were not significant (P > 0.05). In the group with experience, the instrumentation time did not differ significantly after the fifth canal, and no significant variations in canal dimensions were observed (P > 0.05). CONCLUSIONS: When conducting studies on root canal shaping or educating students with new instruments, a simulated canal sample size of 6 was appropriate to achieve competence.

Evaluation of changes in ion release and biological properties of NeoMTA-Plus and Endocem-MTA exposed to an acidic environment.

AIM: To analyse in vitro changes in ion release and biological properties of Endocem-MTA (Maruchi, Wonju, Korea) and NeoMTA-Plus (Avalon Biomed Inc, Bradenton, FL, USA) exposed to acidic or neutral environment on human dental periodontal ligament stem cells (hPDLSCs). METHODOLOGY: Cell viability and wound healing assays were performed using eluates of each material. Cell death and changes in phenotype induced by the set endodontic sealer eluates were evaluated through flow cytometry. To evaluate cell attachment to the different materials, hPDLSCs were directly seeded onto the material surfaces and analysed by scanning electron microscopy. The chemical composition of the materials was determined by energy-dispersive X-ray (EDX), and ion release was evaluated by inductively coupled plasma-mass spectrometry. Statistical analysis was performed with analysis of variance and a Bonferroni or Tukey post-test (α < 0.05). RESULTS: The MTT assay revealed non-cytotoxic effects of NeoMTA-Plus and Endocem-MTA at pH 5.2 and 7.4. However, there were minor differences compared with the control, especially at pH 5.2, where both materials were associated with significantly greater cell viability (P < 0.05). In both environments, the materials stimulated hPDLSCs to migrate. hPDLSCs were attached to the bioactive cements, with multiple prolongations proliferated on the surface of the samples. Moreover, there were no changes to cell phenotype or apoptosis/necrosis rates, indicating that the acidic environment did not induce cell death. Prismatic crystalline structures were seen on the surface of the cements exposed to butyric acid and EDX analysis identified a marked peak of Ca2+ from NeoMTA-Plus and Endocem-MTA in acidic and physiological environments. CONCLUSIONS: An acidic environment favoured the release of Ca2+ ions from both bioactive cements, and the cytotoxicity of these bioactive cements was low in both environments studied.

Biological effects of silk fibroin 3D scaffolds on stem cells from human exfoliated deciduous teeth (SHEDs).

The aim is to investigate in vitro biological effects of silk fibroin 3D scaffolds on stem cells from human exfoliated deciduous teeth (SHEDs) in terms of proliferation, morphological appearance, cell viability, and expression of mesenchymal stem cell markers. Silk fibroin 3D scaffolding materials may represent promising suitable scaffolds for their application in regenerative endodontic therapy approaches. SHEDs were cultured in silk fibroin 3D scaffolds. Then, cell numbers were counted and the Alamar blue colorimetric assay was used to analyse cell proliferation after 24, 48, 72, and 168 h of culture. The morphological features of SHEDs cultured on silk fibroin scaffolds were evaluated by scanning electron microscopy (SEM). Finally, cell viability and the expression of mesenchymal stem cell markers were analysed by flow cytometry. One-way analysis of variance (ANOVA) followed by a Bonferroni post-test was performed (P < 0.05). At 24 and 48 h of culture, SHED proliferation on scaffolds was modest compared to the control although still significant (p < 0.05). However, cell proliferation progressively increased from 72 to 168 h compared with the control (p < 0.001; p < 0.01). In addition, flow cytometry analysis showed that the culture of SHEDs on silk fibroin scaffolds did not significantly alter the level of expression of the mesenchymal markers CD73, CD90, or CD105 up to 168 h; in addition, cell viability in silk fibroin was similar to than obtained in plastic. Moreover, SEM studies revealed a suitable degree of proliferation, cell spreading, and attachment, especially after 168 h of culture. The findings from the current study suggest that silk fibroin 3D scaffolds had a favourable effect on the biological responses of SHEDs. Further in vivo investigations are required to confirm these results.

Implementation of augmented reality in operative dentistry learning.

OBJECTIVE: To evaluate the efficacy of augmented reality (AR) in the gaining of knowledge and skills amongst dental students in the design of cavity preparations and analyse their degree of satisfaction. MATERIAL AND METHODS: AR cavity models were prepared for use with computers and mobile devices. Forty-one students were divided into two groups (traditional teaching methods vs AR). Questionnaires were designed to evaluate knowledge and skills, with the administration of a satisfaction questionnaire for those using AR. The degree of compliance with the standards in cavity design was assessed. The Mann-Whitney U-test was used to compare knowledge and skills between the two groups, and the Wilcoxon test was applied to compare intragroup differences. The chi-square test in turn was used to compare the qualitative parameters of the cavity designs between the groups. Statistical significance was considered for P<.05 in all cases. RESULTS: No significant differences were observed in level of knowledge before, immediately after or 6 months after teaching between the two groups (P>.05). Although the results corresponding to most of the studied skills parameters were better in the experimental group, significant differences (P<.05) were only founded for cavity depth and extent for Class I and divergence of the buccal and lingual walls for the Class II. The experience was rated as favourable or very favourable by 100% of the participants. The students showed preference for computers (60%) vs mobile devices (10%). CONCLUSIONS: The AR techniques favoured the gaining of knowledge and skills and were regarded as a useful tool by the students.

Biocompatibility of three new calcium silicate-based endodontic sealers on human periodontal ligament stem cells.

AIM: To evaluate the biocompatibility of three calcium silicate-based endodontic sealers, Bioroot BC Sealer (Septodont, Saint-Maur-des-Fosses, France), Endoseal MTA (EndoSeal, Maruchi, Seoul, Korea) and Nano-ceramic Sealer (B&L Biotech, Fairfax, VA, USA) (NCS), on human periodontal ligament stem cells (hPDLSCs). METHODOLOGY: Human periodontal ligament stem cells were cultured in the presence of various endodontic sealer eluates for 24 h. Cell viability was determined using the MTT assay. Cell death and changes in phenotype induced by the set endodontic sealer eluates were evaluated through flow cytometry. Also, an in vitro scratch wound-healing model was used to determine their effects in cell migration. Finally, to assess cell morphology and attachment to the different sealers, hPDLSCs were directly seeded onto the material surfaces and analysed by scanning electron microscopy (SEM). One-way analysis of variance (anova) followed by a Bonferroni post-test was performed (P < 0.05). RESULTS: At 24 h, cell spreading was evident in the presence of Bioroot BC Sealer (BR) and Nano-ceramic Sealer (NCS), but not Endoseal MTA (ES). At 72 h, BR and NCS exhibited high and moderate cell proliferation, respectively, whereas ES revealed low rates of cell proliferation (P < 0.05). Similar results were obtained in a cell death assay. In addition, hPDLSCs maintained their mesenchymal phenotype in all conditions although their capacity to migrate was higher in the presence of BR. Finally, SEM studies revealed a good degree of proliferation, cell spreading and attachment, especially when using BR and NCS discs. CONCLUSIONS: BR and NCS were associated with better cytocompatibility than ES. Further in vitro and in vivo investigations are required to confirm the suitability of these calcium silicate-based endodontic sealers for clinical application.

Evaluation of cytocompatibility of calcium silicate-based endodontic sealers and their effects on the biological responses of mesenchymal dental stem cells.

AIM: To investigate in vitro the cytocompatibility of the calcium silicate-containing endodontic sealers MTA Fillapex and TotalFill BC Sealer on human periodontal ligament stem cells (hPDLSCs) by assaying their biological responses and compare them with that observed when using an epoxy resin-based sealer (AH Plus). METHODOLOGY: Specimens from the three different endodontic sealers were eluated with culture medium for 24 h. The cytotoxicity of these eluates was evaluated using the MTT assay. In addition, an in vitro scratch wound healing model was used to determine their effects on cell migration. Cell adhesion to collagen type I after treatment with the different sealer eluates was also measured, whereas cytotoxicity was determined using the DNA-specific fluorochrome Hoechst 33342. Finally, to assess cell morphology and attachment to the different sealers, hPDLSCs were directly seeded onto the material surfaces and analysed by scanning electron microscopy (SEM). One-way analysis of variance (anova) followed by a Bonferroni post-test were performed (P < 0.05). RESULTS: hPDLSCs exposed to different dilutions of TotalFill BC Sealer eluates had significantly higher cell proliferation compared with that observed when cells were treated with AH Plus and MTA Fillapex eluates (P < 0.001). In addition, TotalFill eluates were associated with significantly increased cell adhesion to collagen type I and migration of hPDLSCs in a concentration-dependent manner than displayed after treatment with MTA Fillapex or AH Plus eluates (P < 0.001). Moreover, TotalFill BC Sealer-induced cytotoxicity was significantly lower than observed using AH Plus and MTA Fillapex eluates (P < 0.001). Finally, SEM studies revealed suitable proliferation, cell spreading and attachment, especially when using TotalFill BC Sealer discs. CONCLUSION: TotalFill BC Sealer exhibited a higher cytocompatibility than AH Plus and MTA Fillapex. Further investigations using in vivo animal models are required to validate the potential biological responses of TotalFill BC Sealer on hPDLSCs.

Cytotoxicity and bioactivity of various pulpotomy materials on stem cells from human exfoliated primary teeth.

AIMS: To investigate the cytotoxicity and bioactivity of several pulpotomy materials: Biodentine (Septodont, Saint-Maur-des-Fosses, France) MTA (Angelus, Londrina, PR, Brazil), Theracal LC (Bisco Inc., Schamburg, IL, USA) and IRM (Dentsply DeTrey GmbH, Konstanz, Germany), after contact with stem cells isolated from human exfoliated primary teeth (SHEDs). METHODOLOGY: SHEDs were cultured in the presence of the eluates of various pulpotomy materials for 24, 48 and 72 h. Cell viability was determined by mitochondrial dehydrogenase enzymatic (MTT) assay. Apoptosis and changes in cell phenotype were evaluated by flow cytometry. Also, an in vitro scratch wound-healing assay was used to determine their effects on cell migration. To assess cell morphology and attachment to the different pulpotomy materials, SHEDs were directly seeded onto the material surfaces and analysed by scanning electron microscopy (SEM). Finally, the deposition of a calcified matrix in presence of these materials was verified by Alizarin Red staining. Statistical analysis was performed with analysis of variance and Bonferroni or Tukey post-test (α = 0.05). RESULTS: Cell viability in the presence of Biodentine eluates was significantly higher to that obtained using complete medium alone (control; P < 0.01) and was also significantly higher than using MTA Angelus from 48 h of incubation (P < 0.01). However, Theracal LC and IRM were associated with low rates of cell viability (P < 0.001). Similar results were obtained in an apoptosis assay. In addition, SHEDs maintained their mesenchymal phenotype in all conditions although their capacity to migrate was higher in the presence of Biodentine. SEM studies revealed a suitable proliferation rate, cell spreading and attachment, especially when using Biodentine and MTA Angelus discs. Finally, Biodentine eluates significantly induced calcified matrix deposition from 7 days of culture (P < 0.01). CONCLUSIONS: Biodentine exhibited better cytocompatibility and bioactivity than MTA Angelus, Theracal LC and IRM.

Comparative analysis of the biological effects of the endodontic bioactive cements MTA-Angelus, MTA Repair HP and NeoMTA Plus on human dental pulp stem cells.

AIM: To evaluate the biological effects in vitro of MTA-Angelus (MTA-Ang; Angelus, Londrina, PR, Brazil), MTA Repair HP (MTA-HP; Angelus) and NeoMTA Plus (NeoMTA-P; Avalon Biomed Inc, Bradenton, FL, USA) on human dental pulp stem cells (hDPSCs). METHODOLOGY: Cell viability and cell migration assays were performed using eluates of each material. To evaluate cell morphology and cell attachment to the different materials, hDPSCs were directly seeded onto the material surfaces and analysed by immunocytofluorescence and scanning electron microscopy, respectively. The chemical composition of the materials was determined by energy-dispersive X-ray (EDX), and eluates were analysed by inductively coupled plasma-mass spectrometry (ICP-MS). Statistical analysis was performed with the analysis of variance and Bonferroni or Tukey post-test (α < 0.05). RESULTS: Undiluted MTA-Ang, MTA-HP and NeoMTA-P displayed a significant increase in cell viability greater than that obtained using complete medium alone (control) (*P < 0.05; **P < 0.01; ***P < 0.001). Moreover, a cell migration assay revealed cell migration rates after incubation with extracts of MTA-Ang, MTA-HP and NeoMTA-P that were similar to levels obtained in the control group. In addition, stretched cytoskeletal F-actin fibres were detected in the cells treated with the three material extracts. SEM studies revealed a high degree of cell proliferation and attachment on all three materials. EDX analysis demonstrated similar weight percentages of C, O and Ca in all three materials, whilst other elements such as Al, Si and S were also found. CONCLUSIONS: MTA-Ang, MTA-HP and NeoMTA-P were associated with biological effects on hDPSCs in terms of cell proliferation, morphology, migration and attachment.

European Fissure Sealant Guidelines: assessment using AGREE II.

BACKGROUND: Pit and fissure sealants are effective in reducing the incidence of occlusal caries, and multiple clinical practice guidelines (CPGs) have been developed for recommending their proper use. The usefulness of CPGs depends on their quality and on the rigour of the guideline development process. OBJECTIVE: A study was made to assess the quality of current European CPGs based on the Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument, which uses 23 key items rated on a 7-point scale to assess practice guideline development and the quality of reporting. METHODS: A search was conducted for fissure sealant guidelines for preventing caries in children and adults at high and low risk published in the last 10 years. Calibration was carried out before scoring to assess agreement between the appraisers using the AGREE II instrument. RESULTS: The searches identified 19 relevant guidelines, and following application of the inclusion/exclusion criteria, three guidelines were retained for evaluation. The proportion of observed agreement was calculated, expressed by the agreement separately for positive and negative ratings (PA = 0.89, NA = 0-91). The results of the guideline assessments revealed the highest score for the Irish guideline, a moderate score for the French guideline and the lowest score for the European guideline. CONCLUSIONS: Based on the AGREE II instrument, the results obtained show significant variation in the quality assessment of the three European Fissure Sealant Guidelines. Future studies should be carried out both to develop quality dental CPGs and to investigate effective ways of adopting them.

Dental sealant knowledge, opinion, values and practice of Spanish dental hygienists.

OBJECTIVES: Dental sealants have proved to be an effective approach to prevent pit and fissure caries. This study examines the knowledge, opinion, values and practice (KOVP) of dental hygienists concerning sealant use in the southwest region of Andalusia, Spain. METHODS: Spanish dental hygienists (n = 400) volunteered to complete a 31-item, self-administered, pretested questionnaire to assess their knowledge, opinion, values and practice regarding pit and fissure sealants. Wilcoxon matched-pairs signed ranks test, the Friedman nonparametric repeated-measures anova and Spearman's correlation were used to analyse the data. RESULTS: The mean scores for knowledge, opinion, values and practice were 3.57 ± 0.41; 2.17 ± 0.42; 2.58 ± 0.77 and 3.56 ± 0.46, respectively. Knowledge differed by years of experience (P < 0.01) and place of work (P < 0.01); opinion differed by years of experience (P = 0.03) and sector (P < 0.01). Similarly, practice about sealants differed by years of experience (P < 0.01). Conversely, values around sealant placement did not statistically differ by sex, years of experience, practice sector or place of work. Statistically, significant correlations were found between knowledge, opinion and value, while it was found no significant correlation between practice and the other variables (P > 0.05). CONCLUSIONS: Most dental hygienists have sufficient knowledge about pit and fissure sealants. They also acknowledge the importance of use of dental sealants and have positive opinion/attitude about using sealants. Practice of dental sealants in clinics was found adequate. However, they were not following the specific guidelines and standardized procedures.

Novel aberrant genetic and epigenetic events in Friedreich's ataxia.

It is generally accepted that Friedreich's ataxia (FRDA) is caused by a deficiency in frataxin expression, a mitochondrial protein involved in iron homeostasis, which mainly affects the brain, dorsal root ganglia of the spinal cord, heart and in certain cases the pancreas. However, there is little knowledge as to other possible genes that may be affected in this disorder, and which can contribute to its complexity. In the current study we compared human periodontal ligament cells gene expression of healthy individuals and FRDA patients. The expression of active-caspase 3, as well as other apoptosis-related genes, was increased in the FRDA cells. Furthermore, iron-sulphur cluster genes, as well as oxidative stress-related genes were overexpressed in FRDA. Moreover, brain-derived neurotrophic factor, neuregulin 1 and miR-132 were all upregulated. These three genes are capable of regulating the expression of each other. Interestingly, when the cells from FRDA patients were co-cultured in the presence of idebenone and deferiprone, caspase expression decreased while antioxidant gene expression, as well as frataxin expression, increased. Regarding epigenetic mechanisms, the frataxin gene was hypermethylated, compared to the healthy counterparts, in the upstream GAA repetitive region. Of the three DNA methyltransferases, DNMT1 but not DNMT3׳s gene expression was higher in FRDA cells. In conclusion, our data show that FRDA cells present altered expression of genes related to cell cycle, oxidative stress and iron homeostasis which may be implicated in the increased apoptotic levels. Also, the altered expression is in a certain degree normalized in the presence of idebenone and deferiprone.

Treatment of osteonecrosis of the jaw related to bisphosphonates and other antiresorptive agents.

BACKGROUND: The clinical management of medication-related osteonecrosis of the jaw (MRONJ) in patients treated with bisphosphonates and other antiresorptive agents is subject to controversy. The American Association of Oral and Maxillofacial Surgeons (AAOMS) has developed guidelines for the correct management of the disorder which are revised and updated by a panel of experts. MATERIAL AND METHODS: The present systematic review analyzes the different treatments currently used to treat this clinical condition, based on the PRISMA® (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement published in 2009. An electronic Medline search was made of the PubMed database, covering the period 2006-2014. The last search date was 31 December 2014. RESULTS: A total of 29 articles were selected from the initial search according to the different drugs implicated in the appearance of osteonecrosis; the treatment modality used according to the stage of the disease; and the recorded success rate. CONCLUSIONS: It is currently still recommended that the management of MRONJ should be decided according to the stage of the disease - conservative treatment being preferred in early stages without symptoms, while surgical management is preferred in the case of bone exposure with symptoms.

Effects of composite films of silk fibroin and graphene oxide on the proliferation, cell viability and mesenchymal phenotype of periodontal ligament stem cells.

In regenerative dentistry, stem cell-based therapy often requires a scaffold to deliver cells and/or growth factors to the injured site. Graphene oxide (GO) and silk fibroin (SF) are promising biomaterials for tissue engineering as they are both non toxic and promote cell proliferation. On the other hand, periodontal ligament stem cells (PDLSCs) are mesenchymal stem cells readily accessible with a promising use in cell therapy. The purpose of this study was to investigate the effects of composite films of GO, SF and GO combined with fibroin in the mesenchymal phenotype, viability, adhesion and proliferation rate of PDLSCs. PDLSCs obtained from healthy extracted teeth were cultured on GO, SF or combination of GO and SF films up to 10 days. Adhesion level of PDSCs on the different biomaterials were evaluated after 12 h of culture, whereas proliferation rate of cells was assessed using the MTT assay. Level of apoptosis was determined using Annexin-V and 7-AAD and mesenchymal markers expression of PDLSCs were analyzed by flow cytometry. At day 7 of culture, MTT experiments showed a high rate of proliferation of PDLSCs growing on GO films compared to the other tested biomaterials, although it was slightly lower than in plastic (control). However PDLSCs growing in fibroin or GO plus fibroin films showed a discrete proliferation. Importantly, at day 10 of culture it was observed a significant increase in PDLSCs proliferation rate in GO films compared to plastic (P < 0.05), as well as in GO plus fibroin compared to fibroin alone (P < 0.001). Flow cytometry analysis showed that culture of PDLSCs in fibroin, GO or GO plus fibroin films did not significantly alter the level of expression of the mesenchymal markers CD73, CD90 or CD105 up to 168 h, being the cell viability in GO even better than obtained in plastic. Our findings suggest that the combination of human dental stem cells/fibroin/GO based-bioengineered constructs have strong potential for their therapeutic use in regenerative dentistry.

Effects of two low-shrinkage composites on dental stem cells (viability, cell damaged or apoptosis and mesenchymal markers expression).

To investigate the effects of new two low-shrinkage composites SDR(®) and Venus(®)Bulk Fill on the cell viability, cellular damage and expression of mesenchymal markers on dental stem cells. Specimens from two low-shrinkage composites were eluted with culture medium for 24 h. After 24 h of incubation, cytotoxicity of elutes were evaluated by MTT assay; apoptosis was determined using the DNA-specific fluorochrome Hoechst 33342 and the mesenchymal stem cells markers expression was analyzed by immunofluorescence staining. After 24 h of cell exposure to each extract media, dental stem cells expressed MSCs markers. The interaction among the material and cell line was not significantly correlated [F(1,60) = 2.251, P = 0.39], whereas statistically significant differences among cells lines were observed [F(1,60) = 9.157, P = 0.004], being dental pulp stem cells more resistant that periodontal ligament stem cells. Also, we did not find any significant effect between the tested materials [F(1,60) = 0.090, P = 0.765]. Furthermore, a very low proportion of exposed cells showed condensed or fragmented nuclei, typical of apoptotic cells at 24 h. The results suggest that SDR(®) and Venus(®) Bulk fill and should be considered when selecting an appropriate resin-based dental restorative material.

Mesenchymal stem cells derived from dental tissues.

Regeneration of tissues occurs naturally due to the existence of stem cells with the capacity to self-regenerate and differentiate; however, regenerative capacity decreases with age, and in many cases, regeneration is not sufficient to repair the damage produced by degenerative, ischaemic, inflammatory, or tumour-based diseases. In the last decade, advances have been made in the understanding of stem cells, the genes that control the alternative fates of quiescence and differentiation, and the niches that provide specific signals that modulate cell fate decisions. Embryonic stem-cell research is shedding light on the secrets of development. Adult stem cells (AS cells) are available from several sources. Bone marrow and connective tissue have been used in preliminary clinical trials for regenerative therapy. Recently, several types of AS cells have been isolated from teeth, including dental pulp stem cells, stem cells from human exfoliated deciduous teeth, periodontal ligament stem cells, dental follicle progenitor stem cells and stem cells from apical papilla. Preliminary data suggest that these cells have the capacity to differentiate into osteoblasts, adipocytes, chondrocytes and neural cells. If confirmed, these data would support the use of these cells, which are easily obtained from extracted teeth, in dental therapies, including in regenerative endodontics, providing a new therapeutic modality.