Mineral Content Of Dentin Research Articles

Assessing the impact of different Urushiol primer solvents on dentin remineralization and bond strength.

To investigate urushiol's potential as a dentin cross-linking agent, promoting remineralization of etched dentin and preventing activation of endogenous proteases causing collagen degradation within the hybrid layer. The goal is to improve bond strength and durability at the resin-dentin interface. Urushiol primers with varying concentrations were prepared using ethanol and dimethyl sulfoxide (DMSO) as solvents. Dentin from healthy molars underwent grinding and acid etching for 15s, followed by a 1min application of urushiol primer. After 14 and 28days of remineralization incubation and remineralization were usedtoassessby Attenuated Total Reflection Fourier Transform Infrared spectroscopy (ATR-FTIR), Micro-Raman spectroscopy, X-ray Diffraction (XRD), Atomic Force Microscopy (AFM), Vickers Hardness, Scanning Electron Microscopy (SEM), and Energy X-ray dispersive spectroscopy (EDS). The overall performance of urushiol primers as dentin adhesives was observed by microtensile bond strength (μTBS) testing and nanoleakage assessment. Investigated the inhibitory properties of the urushiol primers on endogenous metalloproteinases (MMPs) utilizing in situ zymography, and the cytotoxicity of the primers was tested. Based on ATR-FTIR, Raman, XRD, EM-EDS and Vickers hardness analyses, the 0.7%-Ethanol group significantly enhanced dentin mineral content and improved mechanical properties the most. Pretreatment notably increased the μTBS of restorations, promoted the stability of the mixed layer, and reduced nanoleakage and MMPs activity after 28days. The urushiol primer facilitates remineralization in demineralized dentin, enhancing remineralization in etched dentin, effectively improving the bonding interface stability, with optimal performance observed at a 0.7 wt% concentration of the urushiol primer.

Effects of ethylenediaminetetraacetic acid, citric acid, and etidronic acid on root dentin mineral content and bond strength of a bioceramic-based sealer: A scanning electron microscopy-energy dispersive spectroscopy study.

This study assessed the impact of chelating agents, 17% ethylenediaminetetraacetic acid (EDTA), 10% citric acid (CA), and 18% etidronic acid (HEDP), on root dentin mineral content. Scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) was applied to analyze changes, and the push-out bond strength test was used to measure dentin adhesion of Well-Root ST, a bioceramic root canal sealer. A total of 80 extracted single-rooted lower premolar teeth were included in this study and randomly divided into four groups (n=20): group 1 (17% EDTA), group 2 (10% CA), group 3 (18% HEDP), and group 4 (distilled water, control). After irrigation and drying, SEM-EDS was applied to analyze eight samples from each group at coronal, middle, and apical root regions for mineral content and SEM images. The remaining 12 samples underwent a push-out bond strength test using Well-Root ST sealer and gutta-percha. Kruskal-Wallis and Dunn's tests were used for statistical analyses. Statistically significant differences were found between groups (P<0.05). SEM-EDS showed significant differences in C, O, Ca, P, and Ca/P content, with no significant differences in Na and Mg. Push-out bond strength was significantly higher in the 17% EDTA, 10% CA, and 18% HEDP groups compared to the control group, with no significant differences between chelating agents. Chelating agents altered root dentin mineral content and improved the adhesive properties of the bioceramic sealer. These findings highlight the importance of considering the selection and use of chelating agents in the clinical practice for root canal treatment.

Effects of a Benzalkonium Chloride Surfactant-Sodium Hypochlorite Combination on Microhardness and Mineral Content of Dentin

This study aimed to investigate the impact of the combination of Benzalkonium chloride (BAC) and sodium hypochloride (NaOCl) and its application after ethylenediaminetetraacetic acid (EDTA) in root canal irrigation procedures on the microhardness and mineral content of dentin. Distal roots of mandibular third molars were embedded in auto-polymerizing acrylic resin, sectioned coronally to apically resulting in fifty-four root sections. Thirty sections underwent microhardness evaluation, and twenty-four sections were randomly chosen for mineral analysis. The microhardness assessment comprised three groups: Group 1 (2.5% NaOCl), Group 2 (2.5% NaOCl with 0.084% BAC), and Group 3 (2.5% NaOCl with 0.084 BAC post-17% EDTA). Initial and post-irrigation microhardness values were measured for each group. For mineral analysis, samples were categorized into four groups: distilled water, 2.5% NaOCl, 2.5% NaOCl with 0.084% BAC, and 17% EDTA+2.5% NaOCl with 0.084% BAC. X-ray photoelectron spectroscopy immediately measured magnesium, phosphorus, and calcium mineral contents on dentin surfaces post-irrigation. Results indicated a significant reduction in root dentin microhardness for all solutions (p&lt;0.05). However, no statistically significant difference in the percentage of reduction was observed among the groups (p&gt;0.05). XPS analysis revealed no significant disparity in dentin surface mineral content among the groups (p&gt;0.05). In conclusion, the addition of Benzalkonium chloride to sodium hypochloride, either alone or after EDTA, did not induce a significant alteration in dentin microhardness or mineral content. These findings contribute to a nuanced understanding of dental irrigation protocols and their effects on dentin properties during endodontic procedures.

Glass ionomer cement with calcium-releasing particles: Effect on dentin mineral content and mechanical properties

Objectiveto evaluate the effect a glass ionomer cement (GIC) containing hydroxyapatite (HAp) or calcium silicate (CaSi) particles on mineral content and mechanical properties of demineralized dentin. Ion release and compressive strength (CS) of the cements were also evaluated. MethodsGIC (Fuji 9 Gold Label, GC), GIC+ 5%HAp and GIC+ 5%CaSi (by mass) were evaluated. Ion release was determined by induced coupled plasma optical emission spectroscopy (Ca2+/Sr2+) or ion-specific electrode (F-) (n = 3). A composite (Filtek Z250, 3 M ESPE) was used as control in remineralization tests. Demineralized dentin discs were kept in contact with materials in simulated body fluid (SBF) at 37 °C for eight weeks. Mineral:matrix ratio (MMR) was determined by ATR-FTIR spectroscopy (n = 5). Dentin hardness (H) and elastic modulus (E) were determined by nanoindentation (n = 10). CS was tested after 24 h and 7d in deionized water (n = 12). Data were analyzed by ANOVA/Tukey test (α = 0.05). ResultsCa2+ and Sr2+ release was higher for the modified materials (p < 0.05). Only GIC+ 5%HAp showed higher F- release than the control (p < 0.05). All groups showed statistically significant increases in MMR, with no differences among them after 8 weeks (p > 0.05). No differences in dentin H or E were observed among groups (p > 0.05). HAp-modified GIC showed increased initial CS, while adding CaSi had the opposite effect (p < 0.05). After 7 days, GIC+ 5%CaSi presented lower CS in relation to control and GIC+ 5%HAp (p < 0.05). SignificanceGIC modification with HAp or CaSi affected CS and increased ion release; however, none of the groups showed evidence of dentin remineralization in comparison to the negative control.

Comparative assessment of antibacterial effect of two types of laser and their effect on morphology and mineral content of dentin

Background/aim Scientists have proven that the main cause of endodontic diseases and failures is the existence of micro-organisms in the root canals and inside the dentinal tubules. So the aim of the study was to compare the antibacterial effect of Erbium, chromium-doped yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser and diode laser 980 nm alone and in combination with 5.25% sodium hypochlorite (NaOCl) irrigant against Enterococcus faecalis biofilm and also compare their effect on the morphology and mineral content of root canal dentin by scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDX) analysis. Materials and methods The specimens used in our study were fifty four extracted human single-rooted teeth. They were collected from the Dental Department of the Research Institute of Ophthalmology, Egypt. Mechanical preparation was done to all teeth after their crowns were removed. They were autoclaved, and after that, they were inoculated with Enterococcus faecalis for 30 days. Roots were divided into six groups (each=9) according to type of treatment. Group A: 5.25% NaOCl, group B: Er,Cr:YSGG laser, group C: 5.25% NaOCl and Er,Cr:YSGG laser, group D: diode laser 980 nm, group E: 5.25% NaOCl and diode laser 980 nm, in addition to control group: saline. Their antibacterial effect was assessed before and after treatment. Changes in the morphology and mineral content of root canal dentin were assessed by SEM and EDX. Statistical analysis was done. Results Group C had significantly the highest percentage of Enterococcus faecalis reduction (98.95%), followed by group E (98.04%), then group D (95.27%), then group A (94.65%), then group B (92.99%), while the control group had significantly the lowest percentage of Enterococcus faecalis reduction (0.22%). Regarding SEM results, group B and group D exhibited score 1 (88.9%), control group and group C score 3 (77.8%), group A score 4 (88.9%), and group E score 5 (88.9%). Regarding EDX results, group B was significantly the lowest in Ca/P ratio, while there was an insignificant difference between other groups. Conclusions Er,Cr:YSGG laser, and diode laser, when used without 5.25% NaOCl irrigant, produced less morphological changes to dentinal tubules, but when combined with 52.5% NaOCl irrigant, produced more antibacterial effect against Enterococcus faecalis. Lasers alone or combined with 5.25% NaOCl irrigant produced changes in the mineral content of root canal dentin.

Evaluation of Effects of Various Irrigating Solutions on Chemical Structure of Root Canal Dentin Using FTIR, SEM, and EDS: An In Vitro Study.

Background: Sequential chemical application for irrigating a root canal during chemomechanical debridement can affect the dentin microstructure. Understanding the effects of various irrigants on chemical properties of dentin can elucidate their effects on physical properties and thereby explain the higher incidence of structural failure in endodontically treated teeth. This in vitro research aimed to compare and evaluate the effects of three different irrigating solutions on the chemical structure of root canal dentin in extracted human teeth. Methods: Forty-eight extracted single-rooted mandibular premolar teeth were sectioned at the cemento–enamel junction by a diamond disc and were then randomly assigned to four groups of twelve samples each. The groups were irrigated using 5.25% NaOCl, ozonated olive oil, silver citrate, or distilled water. Dentin sections measuring 1.5 mm were obtained from the root portion and each section and were analyzed using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and electron-dispersive spectroscopy (EDS). FTIR and EDS values are reported as means ± standard deviations. Data were analyzed using an ANOVA and a post hoc Bonferroni test (p < 0.05). Results: A comparison of the FTIR and EDS values among the groups using ANOVA revealed statistically significant differences in the organic and inorganic peak values among the groups. An intergroup comparison between NaOCl with silver citrate and ozonated olive oil revealed significant reductions in the carbonate and phosphate peak values in the NaOCl group (p < 0.05). The EDS values tabulated for the carbon, oxygen, phosphorous, and calcium peak levels showed significant differences between the groups using an ANOVA. An SEM analysis was conducted under 1500× magnification, which revealed smear layer removal in the silver citrate group. Conclusions: The silver citrate solution and the ozonated olive oil caused less changes in the organic and mineral contents of dentin than sodium hypochlorite.

Evolution of the combined effect of different irrigation solutions and activation techniques on the removal of smear layer and dentin microhardness in oval-shaped root canal: An in-vitro study.

The aim of this in vitro study was to evaluate the effect of three final irrigants, namely QMix, MTAD and EDTA, combined with three irrigation techniques, namely conventional needle irrigation (CNI), passive ultrasonic irrigation (PUI) and photon-induced photoacoustic streaming (PIPS), on smear layer removal, dentin mineral content and microhardness in oval-shaped canals. 130 decoronated premolars with single, oval root canals were equally divided into1 blank control group and 12 treatment groups (n=10) according to the final irrigation protocols. Roots in treatment groups were instrumented with ProTaper Gold to size F4 and subjected to final irrigation. Smear layer removal was assessed by using a four-level scoring system under an environmental scanning electron microscope. Energy dispersive X-ray spectroscopy was performed to measure the dentin mineral content. Dentin microhardness was measured by Knoop microhardness testing. Statistical analysis of the data was performed by using Kruskal-Wallis test, followed by Dunn's post hoc test with Bonferroni correction. PUI- and PIPS-activated QMix and EDTA removed smear layer more effectively than MTAD groups (p<0.05). Regarding the dentin mineral content and microhardness, QMix groups yielded the least calcium (Ca), phosphorus (P) and Ca/P ratio, followed by EDTA groups and MTAD groups (p<0.05). QMix groups produced significantly lower dentin microhardness values and higher hardness reduction percentages than MTAD groups (p<0.05). Within the limitations of the present study, it was concluded that QMix and EDTA were superior to MTAD in smear layer removal, especially when activated by PUI and PIPS, but these agents produced more pronounced effect on dentin mineral content and microhardness than MTAD.

Evaluation of various laser irradiations on the dentin tissue permeability

Background: Dental tissue that has been irradiated with a laser undergoes morphological and chemical changes. Because the magnitude of these changes is influenced by the absorption qualities of the tissue, it is possible that these alterations will vary depending on the kind of laser used and the dental tissue. Objective: The purpose of this research was to evaluate the mineral content of dentin irradiated with CO2 10600nm, Diode 980nm and Er:Cr: YSGG 2780nm. Material and method: One hundred extracted molars were utilised for the study, and the samples were split into five groups. Next, the enamel was scraped from the dentin surface using a standard bur while abundant coolant was applied. A low-speed diamond stone was used to prepare the teeth, resulting in the creation of two slabs for each tooth. The dentine of samples were irradiated to .5 watt of co2, diode, Er:Cr: YSGG lasers with nano ZnO-HA and without. Calcium (Ca) and phosphorous (P) were measured and analysed using a Scanning Electron Microscope (SEM) in conjunction with Energy Dispersive X-ray (EDX).

Comparative evaluation of chelating efficacy of nano-chitosan, pomegranate extract, and ethylenediaminetetraacetic acid on primary radicular dentin: An in vitro study.

Irrigation is a crucial aspect of root canal treatment, and it is imperative to employ chelating agents to eliminate the smear layer during biomechanical preparation. They in turn react with mineral content of dentin, leading to decreased strength and increased susceptibility to fracture. This study aimed to assess and compare mineral loss and microhardness from primary root canal dentin following the usage of different irrigating solutions and determine the least detrimental irrigant among the tested solutions. Sixty-six primary anterior teeth were divided into three groups with 22 in each- Group I: 17% ethylenediaminetetraacetic acid (EDTA) Group II: 0.2% Nano chitosan Group III: Pomegranate extract. The decoronated teeth were split longitudinally. Half of it was directly subjected to Vickers test, and the other half was immersed in a magnetic stirrer bath containing test solution to record the mineral loss from solution. Postmicrohardness values were recorded on the specimen and compared with initial values. Statistical analysis was done using SPSS software (Version 20, SPSS, IBM, Armonk, NY, U. S. A). Descriptive statistics were calculated, and the groups were compared using analysis of variance test and post hoc Tukey test. Pomegranate extract showed least effect on mineral content and microhardness compared to 17% EDTA and 0.2% nano chitosan. P ≤ 0.05 was considered statistically significant. Pomegranate aril extract showed better results with selected parameters.

Nanoscopic wear behavior of dentinogenesis imperfecta type II tooth dentin

ObjectivesThe aim of this study was to investigate the wear behavior of Dentinogenesis imperfecta type II (DGI-II) dentin and elucidate the correlation between its tribological properties and components. MethodsThe mid-coronal dentin of normal and DGI-II teeth were divided into two groups: perpendicular and parallel to the dentin tubules. The microstructure of dentin was detected using atomic force microscopy (AFM). The wear behavior of dentin was evaluated by nanoscratch tests and scanning electron microscopy (SEM). Meanwhile, changes in molecular groups and chemical composition were analyzed by Raman and Energy-Dispersive X-ray (EDX) tests, respectively. Nanohardness was also evaluated. ResultsAFM images of DGI-II dentin illustrated a decrease in the number of tubules and the tubule diameter. Nanoscratch test showed a higher friction coefficient and a greater depth-of-scratch in DGI-II dentin. The wear resistance of DGI-II dentin was reduced independent of tubule orientation. EDX results indicated that DGI-II dentin mineral content decreased and Raman spectra results showed DGI-II dentin had a decreased collagen matrix structure stability coupled with hypomineralization. Furthermore, a significant reduction in nanohardness and elastic modulus of DGI-II dentin was observed. Regression analysis revealed a close correlation between dentin components and inferior wear resistance. ConclusionsAll results indicated the wear behavior of DGI-II dentin was significantly deteriorated, presumably caused by the disorder in microstructures and the reduction of chemical composition.

Effect of a new irrigant solution containing glycolic acid on smear layer removal and chemical/mechanical properties of dentin

The objective of this study was to evaluate the effects of glycolic acid (GA) (with pH 1.2 and 5) and ethylenediaminetetraacetic acid (EDTA) on the chemical and mechanical properties of dentin to investigate the potential use of GA as final irrigant in the root canal therapy. Specifically, changes in microhardness, smear layer removal, erosion, mineral content distribution, apatite/collagen ratio and flexural strength of mineralized dentin treated with GA were assessed. Saline solution was used as a negative control. Knoop microhardness (KHN) was measured on the root canal lumen of root segments. Dentin beams were used for 3-point flexural strength (σ) test. Scanning electron microscopy (SEM) images of root sections were obtained for evaluation of smear layer removal and dentin erosion on root segments and energy dispersive X-ray spectroscopy (EDS) was used for mineral content distribution. The apatite/collagen ratio (A/C) in dentin powder were examined by Fourier transform infrared (FTIR) spectroscopy. KHN, σ and A/C results were statistically analyzed with ANOVA and Tukey tests (α = 0.05). Smear layer and dentin erosion scores were analyzed with Kruskal-Wallis and Dunn tests (α = 0.05). Root dentin treated with EDTA and GA presented similar KHN regardless of the pH (p > 0.05). However, KHN was significantly reduced in EDTA and GA groups when compared to control group (p<0.001). GA showed the same ability to remove the smear layer and to cause dentin erosion as EDTA. EDS results showed that the GA and EDTA solutions did not alter the dentin mineral content distribution. The apatite/collagen ratio reduced with all irrigant solution and was the lowest with GA pH 5 (p<0.001), while σ was not significantly affected by the experimental solutions (p = 0.559). It can be concluded that GA has similar ability to remove the smear layer than EDTA. GA does not affect negatively the chemical/mechanical properties and it does not increase dentin erosion. The use of GA with low pH seems to promote less change in collagen/apatite ratio, but further studies are needed to establish an ideal clinical protocol. Therefore, this study supports the potential use of GA as an alternative final irrigation solution for root canal preparation.

Mechanical and Chemical Changes in the Adhesive-Dentin Interface after Remineralization.

To evaluate the remineralization effects of Bioglass 45S5 (BAG) on dentin composition, adhesive-dentin bond strength, as well as interface and diffusion zone thickness. Dentin specimens were assigned to a control group (CG), in which the adhesive was applied following the manufacturer's instructions, and a remineralized group (RG), in which remineralization treatment was carried out by rubbing a remineralization solution (0.015 g of BAG with 1.35 ml of distilled water) on the etched dentin surface for 30 s before applying the adhesive. For bioactive analysis (n = 10), control and remineralized dentin were investigated using micro-Raman spectroscopy (mRS) and scanning electron microscopy (SEM). Stick specimens prepared with a three-step etch-and-rinse adhesive were submitted to a microtensile bond strength (µTBS) test (n = 10) after 24 h (24 h) and eight months (8 m). Micro-RS 3D-maps (n = 10) characterized the adhesive-dentin interface composition and diffusion zone thickness, and SEM images (n = 10) evaluated interface thickness. Data were analyzed using Student's t-test or two-way ANOVA and Tukey-Kramer's post-hoc test (α = 0.05). Remineralization treatment increased the mineral content of dentin. Mean µTBSs were statistically different at 24 h, with RG higher than CG; however, this difference was not significant at 8 m. When the adhesive was applied on remineralized dentin, its penetration was reduced, its physical interaction with phosphate was improved, and its degree of conversion increased. The diffusion zone in the CG did not differ from that of the RG, and interface thickness values of the CG did not differ from that of the RG. Remineralization treatment promoted mineral growth on the dentin surface, improved the interaction of dentin with adhesive monomers, and consequently resulted in higher immediate bond strengths.

Glycolic acid as the final irrigant in endodontics: Mechanical and cytotoxic effects

The aim of this study was to investigate the effects of glycolic acid (GA) on the microhardness, roughness, dentin mineral content distribution; smear layer removal and cytotoxicity. One hundred human teeth were randomly divided into six groups: distilled water (control group), 17% EDTA, 10% citric acid (CA), 5% GA, 10% GA, and, 17% GA. Microhardness and roughness were measured in the canal lumen. Scanning electron microscopy (SEM) images (2000×) for smear layer removal evaluation; energy dispersive X-ray spectroscopy (EDS) for chemical analysis. Cell viability assay was made on fibroblast cells. The lowest microhardness and higher roughness were observed for 17% GA. GA showed the ability to remove the smear layer to a similar level as EDTA and CA, with no statistical difference between the concentrations used. GA and CA were cytotoxic in a dose-dependent manner. GA showed potential as an endodontic agent for final irrigation in root canal terapies.

Does the Photon-Induced Photoacoustic Streaming Activation of Irrigation Solutions Alter the Dentin Microhardness?

Objective: The aim of this in vitro study was to evaluate the efficacy of photon-induced photoacoustic streaming (PIPS) activation of sodium hypochlorite (NaOCl), chlorhexidine (CHX) or ethylenediaminetetraacetic acid (EDTA) on the dentin microhardness and to assess the compositional changes of root dentin. Background data: It is still unclear whether PIPS activation of irrigants alters the dentin microhardness and mineral content of dentin. Materials and methods: Root canals of 72 extracted single-rooted teeth were prepared and teeth were fixed in microcentrifuge tubes with silicone impression material. After setting of the silicone, teeth were removed and split longitudinally in buccolingual direction. One half was used as control (pretreatment) while the other was placed into the tube (posttreatment). Then specimens were divided into six test groups (three with and three without PIPS activation). The irrigants tested were 2.5% NaOCl, 17% EDTA, and 2% CHX. Experimental tooth specimens were irrigated with 6 mL of test solution, with additional PIPS activation applied to the PIPS groups. Then specimens were subjected to Vickers microhardness testing. Percentage change of microhardness was calculated. Energy dispersive X-ray spectroscopy (SEM-EDX) was performed to measure element content. Results: Among the irrigant-alone groups, NaOCl and CHX did not alter the dentin microhardness, whereas statistically lower microhardness values were obtained in EDTA group. Chemical composition of dentin was affected from all irrigants used. PIPS activation led to no additional alteration in dentin microhardness. PIPS significantly increased the phosphorus level in NaOCl group. Conclusions: Dentin microhardness was significantly affected by the irrigation solution, not by the PIPS activation.

Mineral content analysis of root canal dentin using laser-induced breakdown spectroscopy.

ObjectivesThis study aimed to introduce the use of laser-induced breakdown spectroscopy (LIBS) for evaluation of the mineral content of root canal dentin, and to assess whether a correlation exists between LIBS and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) methods by comparing the effects of irrigation solutions on the mineral content change of root canal dentin.Materials and MethodsForty teeth with a single root canal were decoronated and longitudinally sectioned to expose the canals. The root halves were divided into 4 groups (n = 10) according to the solution applied: group NaOCl, 5.25% sodium hypochlorite (NaOCl) for 1 hour; group EDTA, 17% ethylenediaminetetraacetic acid (EDTA) for 2 minutes; group NaOCl+EDTA, 5.25% NaOCl for 1 hour and 17% EDTA for 2 minutes; a control group. Each root half belonging to the same root was evaluated for mineral content with either LIBS or SEM/EDS methods. The data were analyzed statistically.ResultsIn groups NaOCl and NaOCl+EDTA, the calcium (Ca)/phosphorus (P) ratio decreased while the sodium (Na) level increased compared with the other groups (p < 0.05). The magnesium (Mg) level changes were not significant among the groups. A significant positive correlation was found between the results of LIBS and SEM/EDS analyses (r = 0.84, p < 0.001).ConclusionsTreatment with NaOCl for 1 hour altered the mineral content of dentin, while EDTA application for 2 minutes had no effect on the elemental composition. The LIBS method proved to be reliable while providing data for the elemental composition of root canal dentin.

Fast monitoring of tooth erosion caused by medicaments used in the treatment of respiratory diseases by ATR-FTIR and μ-EDXRF analysis.

The present study aimed to evaluate the erosive potential of four most commonly prescribed syrup medicaments for respiratory diseases. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy combined with multivariate statistical analysis and micro-energy-dispersive X-ray fluorescence spectrometry (μ-EDXRF) mapping was performed. Fifty-five root dentin fragments obtained from the buccal surface of 30 bovine teeth were prepared and divided into five experimental groups (n=10): control-artificial saliva (S), acebrofilin hydrochloride (AC), ambroxol hydrochloride (AM), bromhexine hydrochloride (BR), and salbutamol sulfate (SS). The S group was stored only in artificial saliva and the other groups were treated with the medicaments (immersed for 1min in 3mL of the medication, three times daily, with 1-h intervals between the immersion cycles, during 5days, 15 immersion cycles). There were a significant decrease in the Ca and P weight percentages (wt%) for dentin after medication treatments, except for AC (p>0.05). Mineral content of dentin showed a clear gradation with increasing Ca and P wt% reduction in the order S<AC<AM<BR<SS. SS resulted in a significant increase in Ca/P ratio when compared to the control (p<0.001). ATR-FTIR combined with multivariate, statistical analysis can quickly and reliably indicate extent of dentin erosion. Considering syrups with high-erosive potential should always follow with proper oral hygiene practices or search for an alternative medications void of such detrimental effects. Regular and prolonged use of these medicaments might bear the risk of causing erosion.

Ozone Gas Effect on Mineral Content of Dentin exposed to Streptococcus mutans Biofilm: An Energy-dispersive X-ray Evaluation.

This study aims to assess the effect of ozone gas on dentin exposed to Streptococcus mutans biofilm by evaluation of mineral content [log calcium-to-phosphorus (Ca/P)] using energy-dispersive X-ray (EDX) spectroscopy. Five human third molars were sectioned into four slices of dentin and distributed in four groups: I - control (no treatment); II - ozone therapy; III - biofilm development; IV - ozone therapy followed by biofilm development. Mineral content (log Ca/P) was evaluated by EDX. Data were analyzed by analysis of variance and Tukey's test (p < 0.05). Results showed that the mineral content of control group (I) was similar to ozone group (II), and was statistically higher than biofilm (III) and ozone + biofilm (IV). The lowest log Ca/P was determined in biofilm group (III). It can be concluded that ozone gas did not grant preventive effects of demineralization by S. mutans biofilm on dentin surface. Ozone gas therapy may be an alternative noninvasive treatment aiming to reduce the levels of caries-associated microorganisms. This therapy may, thereby, be an alternative and/or complementary treatment strategy in preventive dentistry.

Impact of Chitosan as Chelating Agent on Microhardness and Mineral Content of Intraradicular Dentin

Aim: This study was designed to evaluate the effects of 0.2% chitosan, 2% chitosan and 17% EDTA chelating agents on the microhardness and mineral content of human root canal dentin. Materials and Methods: Sixty extracted single-rooted human teeth were longitudinally sectioned into 120 segments. The specimens were randomly divided into four groups according to the chelating agent used; G1: 0.2% chitosan, G2: 2% chitosan, G3: 17% EDTA and G4: saline (control group). Dentin microhardness was measured in a total of 80 specimens using Vickers diamond indenter with 300 g loadand a dwell time of 20 s. A total volume of 5 mL of each solution was used for 3min and then specimens finally flushed with 10 mL distilled water. In a total of 40 specimens, the level of three elements (calcium, phosphorus and magnesium) in each specimen was analyzed using inductively coupled plasma atomic emission spectrometry (ICPAES).Results: All tested chelating agents significantly decreased the microhardness of root canal dentin (P ≤ 0.05) and reduced the mineral content of dentin. Chitosan 2% and 17% EDTA had the statistically significant highest mean percentage reduction in microhardness compared to the control group (P ≤ 0.05) and showed the maximum loss of Ca ions from root canal dentin. Chitosan 0.2% showed less reduction in dentin microhardness and chelated Ca ions from root dentin. Conclusions: Chitosan 0.2% solution is equally effective to 17% EDTA in removing Ca ions from root canal dentin withoutmuch altering its microhardness. Accordingly, the natural product of 0.2% chitosan attracts its use as dentin chelating agent.

Kök Dentininin Mineral İçeriğine ve AH-Plus?ın Bağlanma Dayanımına Borik Asitin Etkisi: SEM-EDX Çalışması

Kök Dentininin Mineral İçeriğine ve AH-Plus?ın Bağlanma Dayanımına Borik Asitin Etkisi: SEM-EDX Çalışması

Characterization of crocodile teeth: Correlation of composition, microstructure, and hardness

Structure and composition of teeth of the saltwater crocodile Crocodylus porosus were characterized by several high-resolution analytical techniques. X-ray diffraction in combination with elemental analysis and infrared spectroscopy showed that the mineral phase of the teeth is a carbonated calcium-deficient nanocrystalline hydroxyapatite in all three tooth-constituting tissues: Dentin, enamel, and cementum. The fluoride content in the three tissues is very low (<0.1 wt.%) and comparable to that in human teeth. The mineral content of dentin, enamel, and cementum as determined by thermogravimetry is 71.3, 80.5, and 66.8 wt.%, respectively. Synchrotron X-ray microtomography showed the internal structure and allowed to visualize the degree of mineralization in dentin, enamel, and cementum. Virtual sections through the tooth and scanning electron micrographs showed that the enamel layer is comparably thin (100-200 μm). The crystallites in the enamel are oriented perpendicularly to the tooth surface. At the dentin-enamel-junction, the packing density of crystallites decreases, and the crystallites do not display an ordered structure as in the enamel. The microhardness was 0.60±0.05 GPa for dentin, 3.15±0.15 GPa for enamel, 0.26±0.08 GPa for cementum close to the crown, and 0.31±0.04 GPa for cementum close to the root margin. This can be explained with the different degree of mineralization of the different tissue types and is comparable with human teeth.