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1.
Int J Mol Sci ; 25(7)2024 Mar 31.
Article in English | MEDLINE | ID: mdl-38612722

ABSTRACT

Endothelial autophagy plays an important role in the regulation of endothelial function. The inhibition of endothelial autophagy is associated with the reduced expression of protein disulfide isomerase 4 (PDIA-4); however, its role in endothelial cells is not known. Here, we report that endothelial cell-specific loss of PDIA-4 leads to impaired autophagic flux accompanied by loss of endothelial function and apoptosis. Endothelial cell-specific loss of PDIA-4 also induced marked changes in endothelial cell architecture, accompanied by the loss of endothelial markers and the gain of mesenchymal markers consistent with endothelial-to-mesenchymal transition (EndMT). The loss of PDIA-4 activated TGFß-signaling, and inhibition of TGFß-signaling suppressed EndMT in PDIA-4-silenced endothelial cells in vitro. Our findings help elucidate the role of PDIA-4 in endothelial autophagy and endothelial function and provide a potential target to modulate endothelial function and/or limit autophagy and EndMT in (patho-)physiological conditions.


Subject(s)
Endothelial Cells , Protein Disulfide-Isomerases , Protein Disulfide-Isomerases/genetics , Apoptosis , Autophagy , Transforming Growth Factor beta
2.
J Biol Chem ; 299(3): 102921, 2023 03.
Article in English | MEDLINE | ID: mdl-36681124

ABSTRACT

Circulating fatty acid-binding protein 3 (FABP3) is an effective biomarker of myocardial injury and peripheral artery disease (PAD). The endothelium, which forms the inner most layer of every blood vessel, is exposed to higher levels of FABP3 in PAD or following myocardial injury, but the pathophysiological role of endothelial FABP3, the effect of FABP3 exposure on endothelial cells, and related mechanisms are unknown. Here, we aimed to evaluate the pathophysiological role of endothelial FABP3 and related mechanisms in vitro. Our molecular and functional in vitro analyses show that (1) FABP3 is basally expressed in endothelial cells; (2) inflammatory stress in the form of lipopolysaccharide (LPS) upregulated endothelial FABP3 expression; (3) loss of endogenous FABP3 protected endothelial cells against LPS-induced endothelial dysfunction; however, exogenous FABP3 exposure exacerbated LPS-induced inflammation; (4) loss of endogenous FABP3 protected against LPS-induced endothelial dysfunction by promoting cell survival and anti-inflammatory and pro-angiogenic signaling pathways. Together, these findings suggest that gain-of endothelial FABP3 exacerbates, whereas loss-of endothelial FABP3 inhibits LPS-induced endothelial dysfunction by promoting cell survival and anti-inflammatory and pro-angiogenic signaling. We propose that an increased circulating FABP3 in myocardial injury or PAD patients may be detrimental to endothelial function, and therefore, therapies aimed at inhibiting FABP3 may improve endothelial function in diseased states.


Subject(s)
Endothelial Cells , Fatty Acid Binding Protein 3 , Lipopolysaccharides , Humans , Endothelial Cells/pathology , Fatty Acid Binding Protein 3/genetics , Inflammation/chemically induced , Signal Transduction/genetics , Cell Survival/genetics
3.
Eur J Dent Educ ; 27(2): 287-295, 2023 May.
Article in English | MEDLINE | ID: mdl-35412002

ABSTRACT

INTRODUCTION: Dentists can prescribe medications for prophylactic and therapeutic purposes. In Australia, dental graduates can autonomously practise within the scope of their qualifications without needing to undertake an internship post-graduation. Although previous research has identified knowledge gaps amongst dental students in Australia on pharmacology and pharmacotherapeutic knowledge, there has been no published research that qualitatively highlights dental students' knowledge of medication prescribing in Australia. This study aimed to undertake a qualitative analysis of Western Australian dental students' attitudes towards and knowledge of medication prescribing. METHODS: This qualitative case study design employed semi-structured interviews as means of collecting data. It utilised a purposive sampling in penultimate and final year dental students at the University of Western Australia. RESULTS: Twenty dental students participated in the study. Five key themes were identified in the data: current and previous education, application when delivering pharmacology and pharmacotherapeutics, teaching to ensure patient-centred care, supervision and referral to relevant resources. Participants agreed that having previous knowledge in the area provides students with confidence regarding medication prescribing. Furthermore, students in this study valued having guidance when prescribing medications. CONCLUSIONS: This study highlights the complexity of medication prescribing for dental students. It also highlights their experience with the current pharmacology and pharmacotherapeutics curriculum. All students interviewed valued application-based teaching, making it specific to dentistry. If curriculum were to be redeveloped, considering their perceptions may be a valuable tool.


Subject(s)
Education, Dental , Students, Dental , Humans , Western Australia , Australia , Curriculum
4.
PLoS One ; 17(9): e0274487, 2022.
Article in English | MEDLINE | ID: mdl-36149900

ABSTRACT

The endothelium maintains and regulates vascular homeostasis mainly by balancing interplay between vasorelaxation and vasoconstriction via regulating Nitric Oxide (NO) availability. Endothelial nitric oxide synthase (eNOS) is one of three NOS isoforms that catalyses the synthesis of NO to regulate endothelial function. However, eNOS's role in the regulation of endothelial function, such as cell proliferation and migration remain unclear. To gain a better understanding, we genetically knocked down eNOS in cultured endothelial cells using sieNOS and evaluated cell proliferation, migration and also tube forming potential in vitro. To our surprise, loss of eNOS significantly induced endothelial cell proliferation, which was associated with significant downregulation of both cell cycle inhibitor p21 and cell proliferation antigen Ki-67. Knockdown of eNOS induced cell migration but inhibited formation of tube-like structures in vitro. Mechanistically, loss of eNOS was associated with activation of MAPK/ERK and inhibition of PI3-K/AKT signaling pathway. On the contrary, pharmacologic inhibition of eNOS by inhibitors L-NAME or L-NMMA, inhibited cell proliferation. Genetic and pharmacologic inhibition of eNOS, both promoted endothelial cell migration but inhibited tube-forming potential. Our findings confirm that eNOS regulate endothelial function by inversely controlling endothelial cell proliferation and migration, and by directly regulating its tube-forming potential. Differential results obtained following pharmacologic versus genetic inhibition of eNOS indicates a more complex mechanism behind eNOS regulation and activity in endothelial cells, warranting further investigation.


Subject(s)
Endothelial Cells , Nitric Oxide Synthase Type III , Cells, Cultured , Endothelial Cells/metabolism , Endothelium/metabolism , Ki-67 Antigen/metabolism , NG-Nitroarginine Methyl Ester/pharmacology , Nitric Oxide/metabolism , Nitric Oxide Synthase Type III/genetics , Nitric Oxide Synthase Type III/metabolism , Protein Isoforms/metabolism , Proto-Oncogene Proteins c-akt/metabolism , omega-N-Methylarginine/metabolism
5.
J Hypertens ; 40(7): 1303-1313, 2022 07 01.
Article in English | MEDLINE | ID: mdl-35762471

ABSTRACT

OBJECTIVE: Angiotensin II (Ang II)-induced endothelial dysfunction plays an important role in the pathogenesis of cardiovascular diseases such as systemic hypertension, cardiac hypertrophy and atherosclerosis. Recently, long noncoding RNAs (lncRNAs) have been shown to play an essential role in the pathobiology of cardiovascular diseases; however, the effect of Ang II on lncRNAs and coding RNAs expression in endothelial cells has not been evaluated. Accordingly, we sought to evaluate the expression profiles of lncRNAs and coding RNAs in endothelial cells following treatment with Ang II. METHODS: Human umbilical vein endothelial cells (HUVECs) were cultured and treated with Ang II (10-6 mol/l) for 24 h. The cells were then profiled for the expression of lncRNAs and mRNAs using the Arraystar Human lncRNA Expression Microarray V3.0. RESULTS: In HUVECs following Ang II treatment, from a total of 30 584 lncRNA targets screened, 25 targets were significantly upregulated, while 69 were downregulated. In the same HUVECs samples, from 26 106 mRNA targets screened, 28 targets were significantly upregulated and 67 were downregulated. Of the differentially expressed lncRNAs, RP11-354P11.2 and RP11-360F5.1 were the most upregulated (11-fold) and downregulated (three-fold) lncRNAs, respectively. Assigning the differentially regulated genes into functional groups using bioinformatics reveals numerous genes involved in the nucleotide excision repair and ECM-receptor interaction. CONCLUSION: This is the first study to profile the Ang II-induced differentially expressed lncRNAs and mRNAs in human endothelial cells. Our results reveal novel targets and substantially extend the list of potential candidate genes involved in Ang II-induced endothelial dysfunction and cardiovascular diseases.


Subject(s)
Cardiovascular Diseases , RNA, Long Noncoding , Angiotensin II/metabolism , Angiotensin II/pharmacology , Cardiovascular Diseases/metabolism , Human Umbilical Vein Endothelial Cells/metabolism , Humans , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Transcriptome
6.
Sci Rep ; 12(1): 7462, 2022 05 06.
Article in English | MEDLINE | ID: mdl-35523808

ABSTRACT

No previous studies have investigated eye-movement patterns to show children's information processing while viewing clinical images. Therefore, this study aimed to explore children and their educators' perception of a midline diastema by applying eye-movement analysis using the hidden Markov models (EMHMM). A total of 155 children between 2.5 and 5.5 years of age and their educators (n = 34) viewed pictures with and without a midline diastema while Tobii Pro Nano eye-tracker followed their eye movements. Fixation data were analysed using data-driven, and fixed regions of interest (ROIs) approaches with EMHMM. Two different eye-movement patterns were identified: explorative pattern (76%), where the children's ROIs were predominantly around the nose and mouth, and focused pattern (26%), where children's ROIs were precise, locating on the teeth with and without a diastema, and fixations transited among the ROIs with similar frequencies. Females had a significantly higher eye-movement preference for without diastema image than males. Comparisons between the different age groups showed a statistically significant difference for overall entropies. The 3.6-4.5y age groups exhibited higher entropies, indicating lower eye-movement consistency. In addition, children and their educators exhibited two specific eye-movement patterns. Children in the explorative pattern saw the midline diastema more often while their educators focussed on the image without diastema. Thus, EMHMMs are valuable in analysing eye-movement patterns in children and adults.


Subject(s)
Diastema , Eye Movements , Adult , Attention , Child , Face , Female , Humans , Male , Mouth
7.
Dent Traumatol ; 38(5): 410-416, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35460595

ABSTRACT

BACKGROUND/AIM: Traumatic dental injuries (TDIs) in the primary dentition may result in tooth discolouration and fractures. The aim of this child-centred study was to explore the differences between preschool children's eye movement patterns and visual attention to typical outcomes following TDIs to primary teeth. MATERIALS AND METHODS: An eye-tracker recorded 155 healthy preschool children's eye movements when they viewed clinical images of healthy teeth, tooth fractures and discolourations. The visual search pattern was analysed using the eye movement analysis with the Hidden Markov Models (EMHMM) approach and preference for the various regions of interest (ROIs). RESULTS: Two different eye movement patterns (distributed and selective) were identified (p < .05). Children with the distributed pattern shifted their fixations between the presented images, while those with the selective pattern remained focused on the same image they first saw. CONCLUSIONS: Preschool children noticed teeth. However, most of them did not have an attentional bias, implying that they did not interpret these TDI outcomes negatively. Only a few children avoided looking at images with TDIs indicating a potential negative impact. The EMHMM approach is appropriate for assessing inter-individual differences in children's visual attention to TDI outcomes.


Subject(s)
Tooth Fractures , Tooth Injuries , Child, Preschool , Eye-Tracking Technology , Humans , Tooth, Deciduous
8.
Int Dent J ; 72(5): 607-620, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35367044

ABSTRACT

OBJECTIVES: Studies reviewing orofacial mycoses in coronavirus disease-2019 (COVID-19) caused by severe acute respiratory syndrome 2 (SARS-CoV-2) infection are sparse. Here we review the major oral and maxillofacial mycoses of COVID-19, the associated comorbidities, and the probable precipitating factors. METHODS: English-language manuscripts published between March 2020 and October 2021 were searched using PubMed, OVID, SCOPUS, and Web of Science databases, using appropriate keywords. RESULTS: We identified 30 articles across 14 countries, which met the inclusion criteria of PRISMA guidelines. These yielded a total of 292 patients with laboratory-confirmed COVID-19, 51.4% (n = 150) of whom presented with oral and maxillofacial fungal infections, mainly comprising candidosis, mucormycosis, and aspergillosis. Candida infections were the most prevalent, present in 64% (n = 96), followed by mucormycosis, and only a single case of aspergillosis was noted. Oral and maxillofacial mycoses were predominantly seen in those with comorbidities, especially in those with diabetes (52.4%). Oral mucormycosis was noted in 8.6% (n = 13) and mainly manifested on the hard palate. An overall event rate of oral/maxillofacial mucormycosis manifestation in patients with COVID-19 with diabetes mellitus type 1/2 was about 94% (49/52; 95% confidence interval, 0.73%-0.89%), implying a very high association between diabetes mellitus and the latter condition. All fungal infections appeared either concurrently with COVID-19 symptoms or during the immediate recovery period. CONCLUSIONS: SARS-CoV-2 infection-related immunosuppression, steroid therapy, as well as comorbidities such as diabetic hyperglycemia appear to be the major predisposing factors for the onset of oral and maxillofacial mycoses in patients with COVID-19 across all age groups.


Subject(s)
COVID-19 , Mycoses , COVID-19/complications , Comorbidity , Humans , Mycoses/diagnosis , SARS-CoV-2 , Steroids
9.
Caries Res ; 56(2): 129-137, 2022.
Article in English | MEDLINE | ID: mdl-35398845

ABSTRACT

Visual attention is a significant gateway to a child's mind, and looking is one of the first behaviors young children develop. Untreated caries and the resulting poor dental aesthetics can have adverse emotional and social impacts on children's oral health-related quality of life due to its detrimental effects on self-esteem and self-concept. Therefore, we explored preschool children's eye movement patterns and visual attention to images with and without dental caries via eye movement analysis using hidden Markov models (EMHMM). We calibrated a convenience sample of 157 preschool children to the eye-tracker (Tobii Nano Pro) to ensure standardization. Consequently, each participant viewed the same standardized pictures with and without dental caries while an eye-tracking device tracked their eye movements. Subsequently, based on the sequence of viewed regions of interest (ROIs), a transition matrix was developed where the participants' previously viewed ROI informed their subsequently considered ROI. Hence, an individual's HMM was estimated from their eye movement data using a variational Bayesian approach to determine the optimal number of ROIs automatically. Consequently, this data-driven approach generated the visual task participants' most representative eye movement patterns. Preschool children exhibited two different eye movement patterns, distributed (78%) and selective (21%), which was statistically significant. Children switched between images with more similar probabilities in the distributed pattern while children remained looking at the same ROI than switching to the other ROI in the selective pattern. Nevertheless, all children exhibited an equal starting fixation on the right or left image and noticed teeth. The study findings reveal that most preschool children did not have an attentional bias to images with and without dental caries. Furthermore, only a few children selectively fixated on images with dental caries. Therefore, selective eye-movement patterns may strongly predict preschool children's sustained visual attention to dental caries. Nevertheless, future studies are essential to fully understand the developmental origins of differences in visual attention to common oral health presentations in children. Finally, EMHMM is appropriate for assessing inter-individual differences in children's visual attention.


Subject(s)
Dental Caries , Bayes Theorem , Child, Preschool , Dental Caries/diagnostic imaging , Eye-Tracking Technology , Humans , Oral Health , Quality of Life
10.
Acta Odontol Scand ; 80(3): 182-190, 2022 Apr.
Article in English | MEDLINE | ID: mdl-34689688

ABSTRACT

AIMS: The coronavirus disease 2019 (COVID-19) due to the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) can present either as an asymptomatic carrier state or an acute respiratory disease, with or without severe pneumonia. The asymptomatic carriers are a challenge for the dental profession as the infection could be transmitted via virus-laden, and saliva in dental settings through aerosol-generating procedures (AGPSs). The aim of this review was to perform a systematic review of SARS-CoV-2 in the saliva of asymptomatic individuals. MATERIALS AND METHODS: PubMed, Google scholar, and MedRxiv databases were searched between and a systematic review and meta-analysis of the available data were performed to assess the viral burden in the saliva of asymptomatic carriers of SARS-CoV-2. All investigators of the included studies used qRT-PCR to detect SARS-CoV-2 and yield quantitative data (the Ct values) appertaining to the viral load. RESULTS: A total of 322 records in the English literature were identified, and eight studies with 2642 SARS-CoV-2-positive and asymptomatic individuals were included in the final analysis. Of these, 16.7% (95% CI: 11-23%) yielded SARS-CoV-2-positive saliva samples in comparison to 13.1% (95% CI: 12-17%) of the respiratory specimens (nasopharyngeal or nose-throat swabs). CONCLUSION: As approximately 1 in 5 to 1 in 10 asymptomatic individuals harbour SARS-CoV-2 in either saliva or respiratory secretions, our results highlight the need for continued vigilance and the critical importance of maintaining strict, additional infection control regimens for the foreseeable future to mitigate the potential risks of COVID-19 transmission in dentistry.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Nasopharynx , Pharynx , Saliva
11.
Physiol Rep ; 9(1): e14661, 2021 01.
Article in English | MEDLINE | ID: mdl-33369888

ABSTRACT

OBJECTIVE: Atherosclerosis is the main cause of the cardiovascular disease (CVD). Elevated blood cholesterol and inflammation of the endothelium are two major mechanisms contributing to the establishment of atherosclerotic plaques. Statins, such as pravastatin, are blood-cholesterol lowering drugs commonly prescribed for patients with or at risk for CVDs. In addition to lowering blood cholesterols, statins have recently been shown to improve endothelial function in both hyper- and normocholesterolemic patients with atherosclerosis. To understand the molecular mechanisms underlying the endothelial function improvement by statins, we assessed the RNA profile of pravastatin-treated endothelial cells, particularly their mRNAs and long non-coding RNAs (lncRNAs). METHODS: Human umbilical vein endothelial cells (HUVECs) treated with pravastatin (10 µM) for 24 hr were profiled for lncRNAs and mRNAs using the Arraystar Human lncRNA Expression Microarray V3.0. RESULTS: Of the 30,584 different lncRNAs screened, 95 were significantly upregulated, while 86 were downregulated in HUVECs responding to pravastatin. LINC00281 and BC045663 were the most upregulated (~8-fold) and downregulated (~3.5-fold) lncRNAs, respectively. Of the 26,106 different mRNAs screened in the pravastatin-treated HUVEC samples, 190 were significantly upregulated, while 90 were downregulated. Assigning the differentially expressed genes by bioinformatics into functional groups revealed their molecular signaling involvement in the following physiological processes: osteoclast differentiation, Rap1 signaling pathway, hematopoiesis, immunity, and neurotrophin signaling pathway. CONCLUSIONS: This is the first lncRNA and mRNA expression profiling of pravastatin-mediated changes in human endothelial cells. Our results reveal potential novel targets and mechanisms for pravastatin-mediated vascular protection in atherosclerosis.


Subject(s)
Endothelium/metabolism , Gene Expression Regulation/drug effects , Human Umbilical Vein Endothelial Cells/metabolism , Pravastatin/pharmacology , RNA, Long Noncoding/genetics , Endothelium/drug effects , Gene Expression Profiling/methods , Human Umbilical Vein Endothelial Cells/drug effects , Humans , Hydroxymethylglutaryl-CoA Reductase Inhibitors/pharmacology , RNA, Messenger/metabolism , Shelterin Complex/metabolism , Signal Transduction , Telomere-Binding Proteins/metabolism
12.
J Clin Med ; 9(11)2020 Oct 22.
Article in English | MEDLINE | ID: mdl-33105856

ABSTRACT

Cardiovascular diseases (CVD) remain a global pandemic and leading cause of deaths worldwide. While several guidelines have been developed to control the development of CVDs, its prevalence keeps on increasing until this day. Cardiovascular risk factors, such as reduced exercises and high fat or glucose diets, culminate in the development of the metabolic syndrome and eventually atherosclerosis, which is driven by high blood lipid and cholesterol levels, and by endothelial dysfunction. Late complications of atherosclerosis give rise to serious clinical cardiovascular manifestations such as myocardial infarction and hypertension. Therefore, endothelial functions and the lipid metabolism play critical roles in the pathogenesis of CVDs. Fatty acid-binding proteins are a family of intracellular proteins expressed in many cell types known mainly for their interaction with and trafficking of cellular lipids. The roles of a number of isoforms in this family have been implicated in lipid metabolic homeostasis, but their influence on endothelial function and vascular homeostasis remain largely unknown. This review's purpose is to update fundamentals about the connection between cardiovascular disease, metabolism, endothelial function, and mainly the roles of fatty acid-binding proteins.

13.
Clin Oral Investig ; 18(3): 753-9, 2014 Apr.
Article in English | MEDLINE | ID: mdl-23832616

ABSTRACT

OBJECTIVES: The main aim of the study was to compare the clinical performance of the conventional high-powder/liquid ratio glass-ionomer cement (GIC) Fuji IX GP Extra (F IX), Fuji IX GP Extra with a low-viscosity nano-filled resin coating, G-Coat Plus (F IX+GCP), and a resin composite, Solare (S), as a comparison material. MATERIALS AND METHODS: Moderate-depth occlusal cavities in the first permanent molars of 91 11-12-year-old children (1-4 restorations per child) were restored with either F IX (87 restorations), F IX+GCP (84 restorations) or S (83 restorations). Direct clinical assessment, photographic assessment and assessment of stone casts of the restorations were carried out at 6 months, 1 year, 2 years and 3 years. RESULTS: The colour match with the tooth of the GIC restorations improved over the 3 years of the study. Marginal staining and marginal adaptation were minimal for all restorations; three restorations exhibited secondary caries at 3 years. From the assessment of the casts, at 2 years, there was significantly less wear of the F IX GP Extra+GCP restorations than the F IX GP Extra restorations (P < 0.005). At 3 years, approximately 37 % of F IX GP Extra restorations showed wear slightly more than the adjacent enamel, compared to 28 % of F IX GP Extra+GCP restorations and 21 % of Solare restorations. Although this was not statistically significant, there was a trend that GCP can protect F IX GP Extra against wear. CONCLUSION: Although both Fuji IX GP Extra and Fuji IX GP Extra with G-Coat Plus showed acceptable clinical performance in occlusal cavities in children, the application of G-Coat Plus gave some protection against wear. CLINICAL RELEVANCE: The application of G-Coat Plus to Fuji IX GP Extra glass-ionomer cement may be beneficial in reducing wear in occlusal cavities.


Subject(s)
Composite Resins , Glass Ionomer Cements , Nanotechnology , Viscosity , Materials Testing
14.
J Dent ; 39 Suppl 2: S20-6, 2011 Dec.
Article in English | MEDLINE | ID: mdl-22101125

ABSTRACT

OBJECTIVES: This study was designed to validate an in vitro model of the Atraumatic Restorative Technique (ART). This model allowed in depth analyses of the migration of apatite forming Sr and F, from a glass-ionomer, Fuji IXGP (GC Corporation, Tokyo, Japan), into partly demineralized dentine. The second objective was to study the effects of the levels of mineral loss on such ionic exchange. METHODS: Artificial lesions were created in thirty third molars, which were divided into three groups based on time of exposure to the demineralizing solution (7, 14 and 21 days). These were restored with Fuji IXGP and left for 21 days. The method of analysis was electron probe microanalysis (EPMA) with wavelength dispersive spectrometry (WDS). This combination can yield both qualitative identification of elements as well as quantitative compositional information, with a minimum detection limit of 0.01%. RESULTS: The results indicated that there was no significant difference in the levels of Ca and P from the control and test sides for all three groups of demineralized dentine. The differences in the depth of penetration and the amount of Sr and F between control and test were significant. CONCLUSIONS: The validity of the in vitro model was confirmed. There was migration of both strontium and fluorine to the artificially demineralized dentine in a pattern consistent with remineralization and similar to what was observed in a previous in vivo study.


Subject(s)
Dental Atraumatic Restorative Treatment/standards , Dentin/metabolism , Glass Ionomer Cements/chemistry , Tooth Demineralization/metabolism , Apatites/chemistry , Calcium/analysis , Electron Probe Microanalysis , Fluorides/pharmacokinetics , Humans , Phosphorus/analysis , Spectrometry, X-Ray Emission , Strontium/pharmacokinetics , Temperature , Time Factors , Tooth Demineralization/therapy , Tooth Remineralization/methods
15.
Quintessence Int ; 40(8): 691-7, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19639093

ABSTRACT

Composite resins and glass-ionomer cements were introduced to dentistry in the 1960s and 1970s, respectively. Since then, there has been a series of modifications to both materials as well as the development other groups claiming intermediate characteristics between the two. The result is a confusion of materials leading to selection problems. While both materials are tooth-colored, there is a considerable difference in their properties, and it is important that each is used in the appropriate situation. Composite resin materials are esthetic and now show acceptable physical strength and wear resistance. However, they are hydrophobic, and therefore more difficult to handle in the oral environment, and cannot support ion migration. Also, the problems of gaining long-term adhesion to dentin have yet to be overcome. On the other hand, glass ionomers are water-based and therefore have the potential for ion migration, both inward and outward from the restoration, leading to a number of advantages. However, they lack the physical properties required for use in load-bearing areas. A logical classification designed to differentiate the materials was first published by McLean et al in 1994, but in the last 15 years, both types of material have undergone further research and modification. This paper is designed to bring the classification up to date so that the operator can make a suitable, evidence-based, choice when selecting a material for any given situation.


Subject(s)
Composite Resins/classification , Dental Restoration, Permanent/methods , Glass Ionomer Cements/classification , Composite Resins/chemistry , Dental Etching/methods , Glass Ionomer Cements/chemistry , Hydrophobic and Hydrophilic Interactions , Ion Exchange , Reference Standards , Self-Curing of Dental Resins
16.
Eur J Oral Sci ; 115(3): 224-9, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17587298

ABSTRACT

This study investigated the effects of environmental calcium/phosphate and pH on the hardness and elastic modulus of two glass-ionomer cements (GICs) [Fuji IX Fast (FN) and KetacMolar (KM)]. Specimens were randomly subjected to storage media of pH 3, 5, and 7. The calcium and phosphate levels of the storage solutions ranged from 0 to 2.4 mM. After 4 wk of conditioning, hardness and elastic modulus were determined using a depth-sensing microindentation test. Sectioned surfaces were observed with scanning electron microscopy. For both FN and KM, no significant change in hardness, elastic modulus, or surface structure were observed at pH 7 and 5, regardless of the concentration of calcium and phosphate. FN and KM specimens conditioned at pH 3 had lower hardness and modulus in comparison to those conditioned at pH 7. An increased level of environmental phosphate led to higher hardness and elastic modulus of FN and KM at pH 3. In general, a microscopic surface reaction layer was observed in specimens conditioned at pH 3. The thickness and structure of the reaction layer varied depending on environmental phosphate levels. The results suggest that the influence of environmental calcium and phosphate on GICs was pH dependent.


Subject(s)
Calcium Phosphates/pharmacology , Glass Ionomer Cements/chemistry , Dental Stress Analysis , Drug Storage , Elasticity , Hardness , Hydrogen-Ion Concentration , Materials Testing , Particle Size , Viscosity
17.
J Dent ; 34(8): 608-13, 2006 Sep.
Article in English | MEDLINE | ID: mdl-16540227

ABSTRACT

OBJECTIVE: To evaluate the remineralization of carious dentine following the restoration of an extensive lesion in a permanent molar with a high strength glass-ionomer cement (GIC). MATERIALS AND METHODS: Thirteen first permanent molars, which were scheduled for extraction because of the presence of extensive caries lesions, were selected for this study. They were first restored, according to the ART technique, using encapsulated Fuji IX(GP), which contains a strontium glass rather than the traditional calcium glass. The cavities were prepared with a clean enamel margin and minimal removal of the carious dentine around the walls. After a period of 1-3 months they were harvested and subsequently sectioned and examined using an electron probe microanalysis (EPMA) and scanning electron microscopy (SEM). RESULTS: EPMA demonstrated that both fluorine and strontium ions had penetrated deep into the underlying demineralized dentine. The only possible source of these ions was the GIC restoration. CONCLUSION: The pattern of penetration of the fluorine and strontium ions into the dentine was consistent with a remineralization process.


Subject(s)
Cariostatic Agents/pharmacokinetics , Dental Caries/therapy , Dental Restoration, Permanent , Glass Ionomer Cements , Tooth Remineralization , Adolescent , Child , Dentin/metabolism , Electron Probe Microanalysis , Fluorine/pharmacokinetics , Humans , Ions , Microscopy, Electron, Scanning , Strontium/pharmacokinetics
18.
Int J Tuberc Lung Dis ; 10(1): 93-8, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16466044

ABSTRACT

SETTING: In West Africa, national tuberculosis programmes (NTPs) face many problems due to the low performance of health care delivery systems and patients' social and cultural environment. OBJECTIVE: To improve the case management of TB in Burkina Faso. DESIGN: Using the operational research process as a tool, TB case management was decentralised from the district hospital to eight primary health care centres in 2003. RESULTS: Twelve months after decentralisation, the quality of case detection remained satisfactory. The delay between the identification of TB suspects with chronic cough and the confirmation of TB was reduced from 13 to 6 days. The detection rate of TB suspects during the study (30%) was twice as high as for 2001 and 2002 (15%). However, the detection rate for smear-positive TB cases decreased from 32.3% in 2001 and 2002 to 6.5% during the year of the study. CONCLUSION: Sufficient time and commitment are essential to obtain a case management system that is decentralised and effective. Efforts therefore need to continue to obtain more information and better results.


Subject(s)
Case Management/organization & administration , Community Health Centers , Tuberculosis, Pulmonary/drug therapy , Burkina Faso , Health Services Accessibility , Hospitals, District , Humans , Patient Compliance , Tuberculosis, Pulmonary/diagnosis
19.
Am J Dent ; 18(3): 188-93, 2005 Jun.
Article in English | MEDLINE | ID: mdl-16158811

ABSTRACT

PURPOSE: To evaluate the mineralization and morphology of residual (infected and affected) carious dentin following the restoration of vital primary molars with viscous glass-ionomer cement (GIC). METHODS: Encapsulated Fuji IX GP and Ketac-Molar Aplicap GICs were placed in cavities that were prepared using the atraumatic restorative treatment (ART) approach. Four suitable exfoliated teeth with intact restorations were sectioned and then examined by electron probe microanalysis (EPMA) and scanning electron microscopy (SEM). RESULTS: EPMA demonstrated the presence of fluorine and strontium that had penetrated into the underlying residual carious dentin from the adjacent GIC. The concentrations of these two elements, and those of calcium and phosphorous, varied with distance from the GIC/dentin interface. SEM showed varying degrees of dentin tubule destruction and intratubular (peritubular) dentin present immediately subjacent to the GIC/dentin interface. Incomplete removal of carious dentin was observed in all specimens, and GIC remained adherent to the tissue.


Subject(s)
Dental Caries/therapy , Dental Restoration Failure , Dental Restoration, Permanent/methods , Glass Ionomer Cements/therapeutic use , Tooth, Deciduous/pathology , Analysis of Variance , Calcium/analysis , Child, Preschool , Dentin/pathology , Electron Probe Microanalysis , Fluorides/analysis , Humans , Microscopy, Electron, Scanning , Molar/pathology , Phosphorus/analysis , Strontium/analysis , Tooth Exfoliation
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