Artificial Saliva pH Research Articles

Formulation and Evaluation of Chlorpheniramine Maleate Troches

The present study was sought to prepare Chlorphenamine (also called chlorpheniramine) maleate troches. Chlorpheni-ramine maleate (CPM) is a first-generation alkyl amine anti histamine used in the prevention of the symptoms of allergic conditions such as rhinitis and urticarial having oral bio availability about 25-50%, it undergoes first pass metabolism. Troches containing CPM was prepared by non-aqueous granulation technology using Xanthum gum, Gum acacia, HPMC K4M and tragacanth and guar gum as the polymers. The effect of varying the concentration of polymer on release of Chlorpheniramine maleate (CPM) from troches was investigated. Differential scanning calorimetry and X-ray powder diffraction spectroscopy were used for physicochemical characterization. Tablets prepared were evaluated for different parameters such as average weight, hardness, Carr’s index, tapped density, friability, disintegration, content uniformity test. All the parameters were found within the specifications. The drug content was estimated by UV spectrophotometer at 261 nm. In vitro drug release studies of troches formulations were performed in artificial saliva pH 6.8 at 37±1oC. Among the all polymers used the highest drug release is shown with xanthum gum due to its less binding capacity. The in vitro release data was subjected to zero order, first order, Higuchi, Korsemeyer-Peppas, Hixon crowell and erosion model in order to establish the drug release mechanism and kinetics of drug release from the lozenge tablets.

Fluoride Release and Uptake Capability of Glass-ionomer Cements and Compomers Used as Dental Restorative Materials

Dental caries and secondary caries are the most common problems in dentistry. Many studies provided evidence for the anticariogenic effect of fluorides. The incidence of secondary caries is decreased in teeth restored with fluoride releasing materials. The purpose of the present in vitro study is to evaluate the fluoride release and uptake capability of two glass-ionomer cements and two compomers. A total number of 60 specimens were prepared according to the manufacturer�s instructions using silicone molds. The specimens were transferred in plastic containers containing artificial saliva (pH=7), incubated at 37�C for 24 h and divided in three subgroups: control group, varnish treated group and dentifrice treated group. The fluoride ion content was measured on five times during a period of 30 days using an Orion 720A fluoride meter with 9609 BN fluoride ion electrode. The self-curing glass-ionomer cement released the highest amounts of fluoride ions at the beginning and after the one month study period. The samples of the four materials tested in the varnish treated groups showed significant differences compared to their control groups on the second day. Dentifrice treated groups did not show significant differences compared to their control groups, except values measured after 30 days. Application of fluoride varnish produced an increase of fluoride release for the first 24 h in case of all materials. However, results suggest that the use of fluoridated dentifrice would be more effective in caries prevention due to their fluoride uptake capability.

Influence of Third Element of TiNi Alloy on Tribological Behavior in Dry and Wet Conditions for Orthodontic Applications

The tribological behavior of Ti49.4Ni50.6, Ti49Ni46Cu5 and Ti50Ni47Co3 (at%) alloy in dry and wet conditions was studied. The alloy was prepared in a Vacuum Arc Re-melting (VAR), homogenized at 800°C for 3600 s and quenched in water. The phase transformation temperatures were measured by differential scanning calorimetry. Before a tribology test, it is necessary to determine surface roughness, because high surface roughness affects friction. The hardness behavior, based on the load over residual indent area, was determined by a Vickers hardness tester. The sliding friction tests were performed using a ball-on-disk tribometer in dry condition at room temperature and wet condition in artificial saliva (pH 5.35) at 37°C (Oral temperature). The results showed that transformation temperature (Af) lowered oral temperature (37°C), this was mainly attributed to the superelastic properties that can be taken into orthodontic applications. The studies showed significant influences in dry condition of coefficient of friction. Caused by the force between the ball and the disk, contact pressure of surface area effect in wear occurred. The debris could not be removed from the surface area tested. TiNiCu and TiNiCo generated significantly lower average coefficient of friction when tested under dry condition, which may have been due to the addition of Cu and Co. Wet condition decreased coefficient of friction more than dry condition, owing to the lubricating effects of artificial saliva.

Bioactive glass composite for orthodontic adhesives — Formation and characterisation of apatites using MAS-NMR and SEM

ObjectivesTo study the dissolution and fluoroapatite (FAP) formation of a new bioactive glass (BAG)-resin adhesive in an acidic solution in reference to neutral solutions, using the magic angle spinning-nuclear magnetic resonance (MAS-NMR) and the scanning electron microscopy (SEM). MethodsBAG composite disks (n = 90) were prepared from, novel fluoride-containing BAG-resin. Three sample groups (n = 30) of the disks were immersed in Tris buffer pH = 7.3 (TB), neutral artificial saliva pH = 7 (AS7) and acidic artificial saliva pH = 4 (AS4) at ten time points (from 6 h to 6 months). Half of the immersed disks at each time point were crushed into a powder and investigated by the solid state MAS-NMR. SEM studies were undertaken by embedding the other half of the immersed disk in a self-cure acrylic where the fracture surface was imaged. ResultsMAS-NMR results show that the BAG composite degraded significantly faster in AS4 compared to TB and AS7. At the end of the immersion period (6 months), around 80% of the glass particles in AS4 had reacted to form an apatite, evidenced by the sharp peak at 2.82 ppm in 31P signals compared to a broader peak in TB and AS7. It also shows evidence of fluorapatite (FAP) formation, indicated by 19F signal at −103 ppm, while signal around −108 ppm indicated the formation of calcium fluoride, from the excess Ca2+ and F− especially on longer immersion. SEM images confirm higher degradation rate of the BAG composite in AS4 and reveal the impact of time on the dissolution of more glass particles. The images also indicate apatite formation around the glass particles in TB and AS4, while it forms predominantly over the disk surface in AS7. SignificanceBAG composite demonstrate smart reactivity in response to pH change which has a potential clinical benefit against demineralization and promoting remineralisation to form more stable fluorapatites.

Microcomputed Tomography Evaluation of Root Dentin Caries Prevention by Topical Fluorides and Potassium Iodide.

The mineral content of dental hard tissues has traditionally been measured by destructive tests such as transverse microradiography. Microfocus X-ray computed tomography (micro CT) has enabled non-destructive 3D assessment of tooth demineralization. This study compared the preventive effects of silver diammine fluoride (SDF) and potassium iodide (KI) in comparison with fluoride varnish. SDF has been known to arrest caries but darkens the tooth. KI creates a precipitate with SDF that reduces the discoloration, but its effects on SDF efficacy in terms of preventing demineralization of at-risk root dentin surfaces is unknown. Bovine root dentin blocks were randomly distributed into four groups and subjected to a pretreatment in each group (n = 8); Control: deionized water (DIW); F-Varnish: 5% sodium fluoride varnish: 38% Saforide; SDF+KI: SDF followed by saturated solution of KI in DIW. The treated dentin was subjected to 8 cycles of demineralization (pH 5) for 14 h and remineralization in artificial saliva (pH 7) for 10 h. Specimens were then scanned for 12 min using micro CT at 73 KV and 1012 µA with 8.3 μm resolution. The 3D images were analyzed in Amira software to calculate lesion depth (LD), surface layer mineral density (SL) and mineral loss (ΔZ) for each specimen. One-way ANOVA with Bonferroni posthoc showed that there was a statistically significant difference between Control and all three other groups for all parameters (P < 0.001), however, there was no statistical difference among F-Varnish, SDF and SDF+KI (P > 0.05). Single application of F-Varnish, SDF and SDF+KI showed comparable preventive effects against root dentin demineralization. Application of KI did not affect anti-demineralization properties of SDF in this study. Micro CT is a quick and effective method for objective and high-resolution characterization of dentin caries lesions.

Radiotherapy Reduces Microhardness and Mineral and Organic Composition, and Changes the Morphology of Primary Teeth: An in vitro Study

Objective: We aimed to evaluate whether radiotherapy causes changes in the mineral composition, hardness, and morphology of enamel and dentin of primary teeth. Materials and Methods: Thirty specimens of primary teeth were subjected to radiotherapy. At baseline and after 1,080, 2,160, and 3,060 cGy, the specimens were subjected to microhardness, FT-Raman spectroscopy, and scanning electron microscopy (SEM) analysis. The pH of artificial saliva was determined, as were the calcium and phosphate concentrations. The data were subjected to the Shapiro-Wilk normality test, showed a nonnormal distribution, and were compared by the Kruskal-Wallis test. Results: The results showed that the microhardness of the enamel surface decreased after 2,160 cGy (281.5 ± 58 kgf/mm²) when compared to baseline (323.6 ± 59.5 kgf/mm²) (p = 0.045). For dentin, the surface hardness decreased after 1,080 cGy (34.9 ± 11.4 kgf/mm²) and 2,160 cGy (26 ± 3.5 kgf/mm²) when compared to baseline (56.5 ± 7.7 kgf/mm²) (p < 0.0001). The mineral and organic contents of phosphate (p < 0.0001), carbonate (p < 0.0001), amide (p = 0.0002), and hydrocarbons (p = 0.0031) of enamel decreased after 3,060 cGy (5,178 ± 1,082, 3,868 ± 524, 999 ± 180, and 959 ± 168 kgf/mm², respectively). For dentin, we noticed a growing increase in phosphate v2, amide, and hydrocarbon content after 1,080 cGy (8,210 ± 2,599, 5,730 ± 1,818, and 6,118 ± 1,807 kgf/mm², respectively) and 2,160 cGy (1,0071 ± 2,547, 7,746 ± 1,916, and 8,280 ± 2,079 kgf/mm², respectively) and a reduction after 3,060 cGy (6,782 ± 2,175, 3,558 ± 1,884, and 3,565 ± 1,867 kgf/mm², respectively) (p < 0.0001). SEM images showed cracks on enamel and degradation of peritubular dentin. Conclusion: We concluded that radiotherapy caused a reduction in surface hardness, changed mineral and organic composition, and promoted morphological changes on the enamel and dentin of primary teeth.

Force degradation trend of latex and nonlatex orthodontic elastics after 48 hours stretching.

BackgroundTwo types of orthodontic elastics exist based on their material, latex and nonlatex, each of which has different properties in clinical use. Some of the differences include their initial force and force degradation over time. This study was conducted to compare the force changes in both materials.AimTo evaluate the force degradation of latex and nonlatex elastics under moderate stretching over time.MethodsMedium-force orthodontic latex and nonlatex elastics from American Orthodontics (AO) and Ortho Technology (OT) of lumen size 1/4 inches and 3/16 inches (total sample 110 elastics) were submerged in artificial saliva (pH 6.7) and incubated for 48 hours. Then, the elastic force was measured at the following time intervals: initial, 1, 3, 6, 12, 24, and 48 hours. Orthodontic latex and nonlatex elastics from AO and OT were analyzed using Fourier-Transform Infrared Spectroscopy and energy-dispersive X-ray to know the chemical bond structure and elements.ResultsThere was a statistically significant difference between latex and nonlatex force degradation over a period of 0–24 hours (P<0.05), while no significant difference existed between 24–48 hours (P>0.05). Force degradation of latex elastics was higher than that of nonlatex elastics. Energy-dispersive X-ray results on nonlatex elastic bands from OT and AO showed higher C element in the latex elastic band from OT, while the latex elastic band from AO had higher Al element.ConclusionMedium-force latex and nonlatex elastics 1/4 inches and 3/16 inches in size both showed force degradation at 1, 3, 6, 12, and 24-hour intervals under 30 mm stretching when kept in artificial saliva (pH 6.7) and incubated at 37°C for 48 hours.

Oral antiseptics and nickel-titanium alloys: mechanical and chemical effects of interaction.

The effect of oral antiseptics on the corrosion of nickel-titanium (NiTi) alloys with various coating was investigated. Uncoated, titanium nitride-coated and rhodium-coated NiTi archwires (0.020 × 0.020″) were tested in interaction with artificial saliva pH 4.8 and oral antiseptics based on hyaluronic acid (Gengigel), chlorhexidine (Curasept) and essential oils in alcohol base (Listerine). The dynamics of nickel and titanium ions release were recorded during 28 days. Springback ratio and modulus of resilience were assessed by three-point bending test. The results showed that corrosion of NiTi is related to type of antiseptic mouth rinse and coating formulations. Exposure to an artificial saliva and antiseptics tend to reduce flexibility and resilience of NiTi archwires. The influence of the media is more significant than the influence of the type of the alloys coating. The largest release of nickel ions is in the first 3 days. Antiseptics do not cause further deterioration of the elastic properties in uncoated NiTi compared to saliva. As a result of exposure of nitrified NiTi wires in Listerine, there is bigger release of nickel ions, decrease in elastic properties and lower force delivery in unload. Listerine tends to reduce elastic properties of rhodium-coated wires also. In conclusion, except for Listerine, changes of mechanical characteristics induced by antiseptics are small and would not have a clinically important impact. Generally, Curasept would be the most suitable option.

In vitro aging behavior of dental composites considering the influence of filler content, storage media and incubation time.

ObjectiveOver time dental composites age due to mechanical impacts such as chewing and chemical impacts such as saliva enzymes and food ingredients. For this research, the focus was placed on chemical degradation. The objective of this study was to simulate hydrolysis by using different food simulating liquids and to assess their impact on the mechanical parameter Vickers microhardness (MHV) and the physicochemical parameter contact angle (CA).MethodsSpecimen of three composites (d = 6 mm, h = 2 mm; n = 435) classified with respect to their filler content (wt%), namely low-filled, medium-filled and highly-filled, were stored for 0, 14, 30, 90 and 180 days in artificial saliva (pH 7), citric acid (pH 3; pH 5), lactic acid (pH 3; pH 5) and ethanol (40%vol; 60%vol) and assessed regarding to MHV and CA. Statistics: Kruskal-Wallis test, stepwise linear regression, bivariate Spearman Rank Correlation (p < 0.05).ResultsWhile stored in artificial saliva, acid and ethanol the CA decreased especially for the low- and medium-filled composites. It was shown that rising the filler content caused less surface changes in the CA. Storage in ethanol led to a significant decrease of MHV of all composites. Regression analysis showed that the effect of in vitro aging on MHV was mainly influenced by the composite material and therefore by filler content (R2 = 0.67; p < 0.05). In contrast, the CA is more influenced by incubation time and filler content (R2 = 0.2; p < 0.05) leading to a higher risk of plaque accumulation over time. Significance: In vitro aging showed significant changes on the mechanical and physicochemical properties of dental composites which may shorten their long-term functionality. In conclusion, it can be stated, that the type of composite material, especially rising filler content seems to improve the materials’ resistance against the processes of chemical degradation.

Evaluation of determinants for the nickel release by the standard orthodontic brackets

The study was aimed to assess the effect of different pH and immersion time on the amount of nickel release from simulated orthodontic appliance of 3M Unitek company. Nickel ion release was evaluated after subjecting the brackets to the simulated artificial oral environment. In this study, 90 stainless steel brackets of 3M Unitek Company were tested by immersing them in artificial saliva of pH 4.2, pH 6.5 and pH 7.6 for a time interval of 1hour, 1 week and 1 month (T1-1h, T2-7 days, T3-30 days) respectively. The data was subjected for the one-way ANOVA and the post-hoc test for the statistical comparison. Means of 2.99±0.77, 9.53±4.26 and 12.65±2 .52 ppb (parts per billion by volume) of nickel were released for 4.2 pH at a time interval of 1hour, 7 days and 1 month respectively. Means of 5.37±2.26, 10.94±1.51 and 16.92±1.69 ppb of nickel were released for 6.5 pH at a time interval of 1hour, 7 days and 1 month respectively. A mean of 2.13±0.92, 0.74±0.54 and 18.83±1.02 ppb of nickel was released for 7.6 pH at a time interval of 1 hr, 7 days and 1 month respectively. pH of the artificial saliva significantly affected the amount of nickel release. Acidic pH was found to increase the amount of nickel release in the artificial saliva. Time duration of bracket immersion significantly affected the amount of nickel release.

Evaluation of the water sorption of luting cements in different solutions.

To evaluate and compare the water sorption of three luting cements in three different solutions: distilled water and artificial saliva with different pH values (7.4 and 3.0). Resin-modified glass-ionomer cement (GC Fuji Plus) and two resin cements (Multilink Automix and Variolink II) were used. A total of 45 specimens - 15 specimens (15x1 mm) for each cement were prepared according to ISO standard 4049:2009. The water sorptions of the cements were calculated by weighing the specimens before and after immersion and desiccation. . Nonparametric statistic methods were applied. GC Fuji Plus cement showed significantly higher values of water sorption in all three solutions of both resin cements (p<0.009) and significantly higher values of sorption in artificial saliva pH 3.0. Multilink Automix showed significantly higher values of water sorption compared with Variolink II in artificial saliva pH 7.4, and higher values of sorption in this solution compared with pH value 3.0. Water sorption values are mainly influenced by the proportion of hydrophilic matrix, the type and composition of filler, and the pH value of solutions.

Effect of oral antiseptics on the corrosion stability of nickel‐titanium orthodontic alloys

The aim was to explore the influence of the interaction of oral antiseptics and various coatings on the corrosion behavior of nickel‐titanium (NiTi) orthodontic alloys. NiTi archwires with uncoated, rhodium‐coated, and nitride‐coated surface were exposed to artificial saliva pH 4.8 at the temperature of 37 °C, and to saliva with the addition of three commercial oral antiseptics (Curaspet, Gengigel, and Listerine). Electrochemical impedance spectroscopy and cyclic polarization were performed. Released nickel and titanium ions after a period of 7 days were measured by inductively coupled optical emission spectroscopy. Results demonstrate that the rate and degree of corrosion mainly increase with the addition of antiseptics. Electrochemical impedance spectroscopy indicates the biggest corrosion resistance in Gengigel. Rhodium‐coated NiTi demonstrates higher corrosion rate in saliva and in all antiseptics than uncoated and nitride‐coated NiTi. The highest tendency toward localized corrosion is seen in rhodium‐coated NiTi in all media, and least in nitride‐coated NiTi. The release of titanium ions mainly supports findings of general corrosion rate. These results indicate that both antiseptics and coating modify corrosion.

Pengaruh Variasi pH Saliva terhadap Perlekatan Streptococcus mutans pada Resin Komposit Nanofil

Nanofilled composite resin restorations are in contact with saliva.Salivary pH affect the hydrolysis process and produce a surface roughness.S.mutansadhesion occur in a rough area of the oral cavity.The aim was to determine the effect of variations in salivary pHonS.mutansadhesion to nanofilled composite resin.Nanofilled composite resin(Filtex Z350XT-3M ESPE)5mm diameter and 2mm thick(N=12)were divided into three groups(n=4)and immersed in 5ml artificial saliva pH 3.5, pH 7, pH 8, incubated 14 days,37°C. Samples were soaked into saliva 1 hour,37 C. Samples were put into bacterial suspension 24 hours,37°C, diluted to 10.0.1ml of the final dilution were cultured on BHI agar, incubated 48 hours,37°C. S.mutans colonies were determined using Colony Counter(CFU/ml). Data were analyzed with One-Way ANOVA test(a=0.05) and LSD0.05. The test showed there is influence ofthe variations in salivary pHonS.mutans adhesionto nanofilled composite resin(p&lt;0.05). Based on LSD0.05 test, there are significant differences between the pH 3.5 group and the pH 7; pH 8 groups, butnot between the pH 7group and the pH 8 group. Variations in salivary pH affectedS.mutansadhesion to nanofilled composite resin.The acidic pH of saliva increased the S.mutansadhesion on nanofilled composite resin compared with the neutral or alkaline.

The effect of prolonged immersion of giomer bulk-fill composite resin on the pH value of artificial saliva and resin surface roughness

This study aimed to determine the effect of immersion time on the surface roughness of Giomer Bulk-Fill composite resin and on the pH value of artificial saliva. Sixty-three specimens were divided into nine groups and immersed in artificial saliva with pH values of 7, 5.5, and 4.5 for 1 hour, 24 hours, and 72 hours at 37 °C. The changes in artificial saliva pH were measured using a pH meter and the surface roughness was measured using a surface roughness tester. Longer immersion time increases the pH of artificial saliva and the surface roughness of Giomer Bulk-Fill composite resin.

Observations of Enamel Microstructure in Incipient Lesions Remineralized by NaF Dentifrices

Synchrotron Radiation (SR) Wide-angle X-ray Diffraction (WAXD) and Small-angle X-ray Scattering (SAXS) techniques were used to assess microstructure of bovine enamel white-spot lesions (WSL) evaluated in a 10-day pH cycling model comprising three different dentifrice groups: (A) 0.21% NaF plus TCP (Clinpro Tooth Crème), (B) 1.1% NaF plus TCP (Clinpro 5000), or (C) 0% NaF (Tom’s of Maine) dentifrice. Each day consisted of four 2-minute treatments, one 4-hour acid challenge (pH=5.0), and immersion in artificial saliva (pH=7.0) between these events. These specimens were also examined with cross-sectional microhardness, digital light microscopy and FE-SEM (field emission scanning electron microscope), and demonstrated the remineralization model effected changes in subsurface microstructure. X-ray diffraction data from WAXD and SAXS were collected on enamel slab cross-sections extending from 0 μm to 150 μm, in 6 μm microbeam increments. A primary outcome of this observational study was that simultaneous WAXD and SAXS measurements were able to resolve significant differences (ANOVA, Student’s t-test, p&lt;0.05) between the effects of the two fluoridecontaining dentifrices on subsurface lesion microstructure. In particular, enamel lesions treated with 1.1% NaF dentifrice group manifested an abundance of nanometer-sized crystallites, while treatment with the 0.21% NaF dentifrice produced larger apatite-like crystals. While the presence of fluoride in both cases promoted regularity in crystal size and orientation, this was not observed for lesions treated without fluoride. Altogether, our observations demonstrate the pathological processes for remineralization are markedly influenced by the presence and concentration of fluoride, the microstructural characteristics of which can be distinguished using the simultaneous WAXD and SAXS technique.

Enamel remineralization effect of a dentifrice containing calcium sodium phosphosilicate: an optical coherence tomography observation

Objective: The purpose of this study was to examine the effects of a dentifrice containing 5% calcium sodium phosphosilicate (CSP) on the remineralization of the enamel using optical coherence tomography (OCT).Materials and methods: Bovine incisors were sliced and shaped in a rectangular form. One group of five specimens was treated with undersaturated 0.1 M lactic acid buffer solution (pH 4.75) for 10 min and then placed in artificial saliva (pH 7.0) (De group). Other specimens were stored in solutions of toothpaste containing CSP for 10 min, followed by 10-min immersion in the lactic acid buffer solution twice a day before storage in artificial saliva (CSP group). An additional group was stored in only artificial saliva (control group). OCT imaging on the selected location of the enamel surface was performed. The peak intensity and width at 1/e2 were recorded in each of the six areas on the sample and averaged, and the sample size of each group was six. The integrated value in units (dB × μm) was calculated in the area of peak intensity. The data for each group was subjected to one-way repeated-measures ANOVA and Tukey HSD tests (α = 0.05).Results: The changes in integrated values of each group were different. A slight but significant increase in the integrated value was observed in the control group, whereas a slight but significant decrease in the value was observed the De group. Integrated values increased in the CSP group.Conclusions: Remineralization occurred upon immersion in the toothpaste containing CSP.

To Compare and Evaluate the Sorption and Solubility of Four Luting Cements after Immersion in Artificial Saliva of Different pH Values.

Introduction:The word ‘luting’ is derived from a latin word ‘Lutum’ which means ‘mud’. ‘Luting’ is a word that is often used to describe the use of a mouldable substance to seal a space or to cement two components together. Therefore in view of the clinical importance of dissolution of luting cements in the oral environment, an in vitro study was designed to compare the sorption and solubility of commercially available luting cements mainly zinc phosphate, Glass Ionomer cement, Resin Modified Glass Ionomer Cement and Resin Cement after immersion in artificial saliva of different ph values of 5 and 7.Aim:To Compare and Evaluate the sorption and solubility of four luting cements after immersion in artificial saliva of different pH values.Materials and Method:A total of 120 test samples were prepared of which 30 samples of each luting cement were prepared for the purpose of assessing the water solubility and sorptionThese luting cements were grouped as: GROUP- A (Zinc Phosphate cement), GROUP- B (Glass Ionomer Cement), GROUP-C (Resin Modified Cement), GROUP- D (Resin Cement) In these groups, based on immersion of artificial saliva of acidic pH 5 and neutral pH7, the luting cement specimens were subdivided into 2 groups of 15 samples each. The volume (V) of each specimen was calculated using mathematical formula.Conclusion:Resin cement had the highest resistance to solubility and sorption followed by resin modified GIC, Conventional GIC, and Zinc Phosphate which exhibited the least resistance to solubility in both artificial saliva of pH 5 and pH 7.

Corrosion Resistance of indigenously Fabricated Dental Magnets for Application in Prosthodontics

ABSTRACT Aim The aim of the study is to evaluate the corrosion resistance of the indigenously fabricated dental magnet. Materials and methods The Teflon-encased Neodymium-Iron-Boron (Nd–Fe–B) magnet was put to test to comply with the standardized conditions. The corrosion behavior was examined using the statistical immersion analysis according to the International Organization for Standardization (ISO) 10271:2001: “Dental metallic materials corrosion test methods.” In this method, the maximum ion release after 7 days was evaluated. The test specimen (magnet) was dipped in corrosive solution for 7 days in polypropylene test tube. Both the control and test magnets were dipped in artificial saliva. The pH of artificial saliva was adjusted to 6.75. After 7 days, the eluate solution was subjected to inductively coupled plasma spectroscopy evaluation to trace the amount of metal ions leached out from the magnets. Results The mean values for Nd, Fe, and B were 329, 532, and 316 µg/cm2 respectively. According to the ISO standards, the tested product values of ions leached out should be within the value of 200 µg/cm2. The release of corrosion products stayed significantly under the limit as specified by the ISO standard 22674:2006 for all the specimens in the test groups. Conclusion Within the limitations of the study, the indigenously fabricated dental magnet had negligible corrosion in comparison with the control group. Clinical significance Magnetic attachments have most commonly been used for the retention of mandibular overdentures. Patients with magnet-retained overdentures have reported a high degree of satisfaction with their dentures. Due to the lack of indigenous fabrication and high costs of imported magnet has led to restricted use of magnets in developing countries. Indigenously developed dental magnets can reduce the cost and make them affordable to our native population. The abutment-friendly benefits of magnetic attachment will help retain the removable prostheses effectively. How to cite this article Guttal SS, Nadiger RK. Corrosion Resistance of indigenously Fabricated Dental Magnets for Application in Prosthodontics. Int J Prosthodont Restor Dent 2017;7(2):48-52.

지르코니아 표면 처리와 인공타액의 pH에 따른 지르코니아와 레진시멘트의 전단결합강도

지르코니아 표면 처리와 인공타액의 pH에 따른 지르코니아와 레진시멘트의 전단결합강도

Perbandingan Kekasaran Permukaan Resin Komposit Nanofiller pada Perendaman Saliva pH Asam

Nanofiller resin composite is a material used for dental restoration which will be in oral cavity so that interacted with the saliva. Saliva pH changes influenced by several factors, including bacteria in the oral cavity, enzymes, hormones and diet. Acid saliva can cause degradation in the composite, this degradation affects the surface roughness of resin composite. The purpose of this study is to compare surface roughness of nanofiller resins composite for 7 and 10 days of immersion in acid saliva.The samples used in this study were cylindrical mould dimension of diameter 5mm x 2mm, then polymerized with a visible light curing unit for 20s. Specimens immersed in acid artificial saliva (pH ± 4) for 7 and 10 days(4 specimens each group)and then stored in incubator at the temperature of 37ºC. The instrument used to measure surface roughness of resin composite was Surface Roughness Measuring Instrument (Surfcom 120A) that expressed in units of µm.Data were analyzedand the result obtainedwas p = 0.263 (p&gt; 0.05), which mean there were no significant differences in the mean roughness of nanofillerresins compositesurface that were immersed in acidic pH for 7 and 10 days. The conclusion of this study was thatthe surface roughness of nanofiller resins composite immersed in acid saliva for 10 days is not rougher than which immersed for 7days.