scholarly journals In Vitro Re-Hardening of Bleached Enamel Using Mineralizing Pastes: Toward Preventing Bacterial Colonization

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 818 ◽  
Author(s):  
Andrea Scribante ◽  
Claudio Poggio ◽  
Simone Gallo ◽  
Paolo Riva ◽  
Antonella Cuocci ◽  
...  
Keyword(s):  
Bacterial Colonization ◽  
Micro Hardness ◽  
Home Agent ◽  
Vickers Hardness Number ◽  
Hardness Tester ◽  
Post Hoc ◽  
To Receive ◽  
Hardness Values ◽  
At Home

The search for materials able to remineralize human hard tissues is a modern medical challenge. In this study, the protective effect on the enamel microhardness by a paste based on hydroxyapatite and sodium fluoride (Remin Pro) was evaluated after two different enamel bleaching procedures. Forty sound human incisors were randomly assigned to different treatments: bleaching with an in-office agent (Perfect Bleach Office+); bleaching with an at-home agent (Perfect Bleach); bleaching with the in-office agent followed by the prophylaxis paste; bleaching with the at-home agent followed by the prophylaxis paste; no treatment (control). Bleaching was performed at 0, 8, 24 and 32 h, followed by a 3-min re-mineralizing treatment in the subgroups designed to receive it. Specimens underwent a micro-hardness tester and a mean Vickers Hardness number was considered for each specimen. ANOVA exhibited significant differences among groups. Post-hoc Tukey testing showed significant micro-hardness decrease after the application of both the two bleaching agents. The treatment with prophylaxis paste significantly increased the micro-hardness values of bleached enamel.

scholarly journals New Resin-Based Bulk-Fill Composites: in vitro Evaluation of Micro-Hardness and Depth of Cure as Infection Risk Indexes

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1308 ◽  
Author(s):  
Marco Colombo ◽  
Simone Gallo ◽  
Claudio Poggio ◽  
Vittorio Ricaldone ◽  
Carla Renata Arciola ◽  
...  
Keyword(s):  
Bacterial Colonization ◽  
Soft Drink ◽  
In Vitro Study ◽  
Internal Surface ◽  
Micro Hardness ◽  
Depth Of Cure ◽  
Hardness Tester ◽  
Hardness Ratio ◽  
Internal Side

The current in vitro study evaluated the Vickers hardness number (VHN) and hardness ratio of four bulk-fill composites (VisCalor bulk; Admira Fusion x-tra; x-tra fil; and GrandioSO x-tra-Voco, Cuxhaven, Germany) to assess the risk of bacterial colonization in comparison with standard composite materials. Thirty samples were prepared for each group. The VHN of both the external (top) and internal surface (bottom) was determined with a micro-hardness tester (200 g load for 15 s), and the hardness ratio was also calculated for each sample. Subsequently, storage in an acidic soft drink (Coca-Cola, Coca-Cola Company, Milano, Italy) was performed; for each group, 10 samples were stored for 1 day, while another 10 were stored for 7 days and the remaining 10 were kept in water as controls. A significant reduction in VHN was shown for all the groups when comparing the external versus internal side (P < 0.05), although the hardness ratio was greater than 0.80, resulting in an adequate polymerization. Regarding the acid storage, all the groups showed a significant decrease of VHN when compared with the controls, both after 1 day (P < 0.05) and after 7 days (P < 0.001). All the products showed adequate depth of cure without further risk of bacterial colonization. However, acid exposure negatively affected micro-hardness values, which might promote subsequent colonization.

scholarly journals Erosive potential of three different commonly used pediatric syrups on deciduous teeth enamel: an in vitro study

2020 ◽  
Vol 7 (10) ◽  
pp. 2041
Author(s):  
Neha Thilak ◽  
Sundeep K. Hedge ◽  
Sham S. Bhat
Keyword(s):  
In Vitro Study ◽  
Titratable Acidity ◽  
Deciduous Teeth ◽  
Hardness Tester ◽  
Titrable Acidity ◽  
Group A ◽  
Group B ◽  
Post Hoc ◽  
Group D

Background: The aim of the study is to compare the erosive potential of three different commonly used pediatric syrups on deciduous teeth enamel. The objectives of the study were to assess the endogeneous pH and titratable acidity of mefenamic acid syrup (meftal P), cetrizine syrup (alerid) and multivitamin syrup (zincovit) and to evaluate the microhardness of the enamel after successive immersion cycles in each of the syrups.Methods: 40 non carious deciduous teeth were included for the study The samples were then randomly allocated into 4 groups (10 in each group): Group A- mefenemic acid syrup (meftal P), Group B- cetrizine syrup (alerid), group C- multivitamin syrup (zincovit) and group D- control (distilled water). The samples were then subjected to the immersion cycles in the syrups. Assessment of enamel surface microhardness was done using Vickers hardness tester at 7th day and 14th day. The pH and titrable acidity of the syrups were also assessed. One way analysis of variance (ANOVA) and post hoc tests were used for the statistical analysis.Results: Out of the test groups, group C showed the lowest pH of around 4.2 and exhibited the largest titrable acidity (22.8 ml) compared with 21 ml in group A and 15.5 ml in group B. At the end of 14th day, group A had microhardness of about 293.43.84±6.34, group B had 299.930±6.85, group C had 313.380±6.23 and group D had 334.190±5.51.Conclusions: All the pediatric liquid medications assessed in the study, meftal P, alerid and zincovit showed acidic pH, high titrable acidities and all the syrups showed loss of microhardness after exposure to the syrups for 14 days. Loss of microhardness was highest for meftal P followed by alerid and least for zincovit.

scholarly journals Perbedaan Penggunaan Bahan Desensitizing dan Tanpa Desensitizing Pasca Bleaching Ekstra-Koronal terhadap Kekerasan Email

2012 ◽  
Vol 19 (2) ◽  
pp. 119
Author(s):  
Wignyo Hadriyanto
Keyword(s):  
Vickers Hardness ◽  
Artificial Saliva ◽  
Hardness Test ◽  
Acrylic Resin ◽  
Micro Hardness ◽  
Vickers Hardness Number ◽  
Hardness Tester ◽  
Group I ◽  
Significant Difference ◽  
The Subject

Latar Belakang. Pada bleaching ekstrakoronal diketahui terjadi proses demineralisasi sehingga terjadi hiersensitivitas dentin. UltraEZ salah satu bahan desensitizing yang dapat mengurangi hipersensitivitas akibat demineralisasi email pasca bleaching ekstrakoronal terkini. Tujuan penelitian ini bertujuan untuk mengetahui perbedaan kekerasan email pasca pemutihan gigi ekstra-koronal dengan aplikasi bahan desensitizing dan tanpa aplikasi bahan desensitizing. Metode penelitian ini menggunakan 20 gigi premolar permanen pasca pencabutanyang masih utuh dan direndam dalam saliva buatan, kemudian dilakukan pemolesan pada bagian bukal dengan menggunakan pasta profilaksis kemudian gigi dicuci dan dikeringkan. Bahan pemutih Opalescence Xtra Boost diaplikasikan pada semua permukaan bukal gigi premolar kemudian dibagi menjadi 2 kelompok yaitu kelompok I, II, masing-masing kelompok sebanyak 10 gigi. Kelompok I sebagai kelompok control setelah dilakukan pemutihan, tidak dilakukan aplikasi Ultra-EZ, dimasukkan dalam wadah botol dan direndam dalam saliva buatan kemudian disimpan dalam incubator. Mahkota dan akar gigi,kemudian ditanam dalam resin akrilik sesuai kelompok sebelumnya dengan permukaan bukal menghadap ke atas. Semua sampel diuji kekerasannya dengan uji kekerasan Vickers menggunakan beban 100 g selama 15 detik. Permukaan bukal menghadap ke atas, kemudian dijepit dengan alat penjepit pada meja alat Micro Vickers Hardness Tester. Sampel diatur sedemikian rupa sehingga akan terlihat gambar yang dapat diukur panjang diagonalnya langsung dengan micrometer yang ada pada lensa okuler. Nilai kekerasan email dalam Vickers hardness number (VHN) juga dapat diperoleh dari table setelah mengetahui rata-rata panjang diagonal, berat badan yang digunakan dan waktu yang digunakan untuk uji kekerasan. Pengujian ini dilakukan pada setiap kelompok. Selanjutnya diuji dengan uji-t. hasil penelitian menunjukkan ada perbedaan yang bermakna antara aplikasi ultraEZ lima menit dibandingkan tanpa aplikasi ultraEZ terhadap kekerasan email pada p>0,05. Background. One of the side effect of bleaching agent is a dentine hypersensitive and ultraEZ is an agent can diminish this process. The purpose of this study was to evaluate difference of enamel microhardness post external bleaching with or without ultra-eze application. Method. Twenty extracted permanent bicuspid used in this study were divided into two group, each group contains 10 bicupids. Group I was treated external bleaching without ultra-eze application and group II was treated external bleaching with application ultraEZ for five minutes. After that all of the subject were seaked the artificial saliva and kept in the incubator 24 hours. Teeth were embedded into acrylic resin with the buccal sirface facing up. Further all of the subject was evaluated by Vickers using 100 g load for 15 seconds. Teeth were stapled on the Micro Hardness Tester table diagonal of emage was measure using micrometer attach on ocular lesnse. Email hardness can be known after calculating, the everage diagonal length, the load used and the duration of hardness test. Further the data was analize using t-test. The result shows there is significant difference between bleaching with and without the application of ultra-eze.

scholarly journals Effect of two different commonly available energy drinks on surface micro hardness of tooth color restorative materials

2014 ◽  
Vol 2 (3) ◽  
pp. 269
Author(s):  
Nazish Fatima ◽  
Mehwish Hussain
Keyword(s):  
Energy Drinks ◽  
Time Interval ◽  
Base Line ◽  
Micro Hardness ◽  
Tooth Color ◽  
Hardness Tester ◽  
Significant Difference ◽  
Restorative Materials ◽  
Insignificant Difference ◽  
Hardness Values

AIM: The objective of present study was to assess the effect of commonly used energy drinks on surface micro hardness of tooth color restorative materials. MATERIAL AND METHODS: Sixty discs of all material were prepared in polytetrafluoroethylene mold which was 10 mm in diameter and 2 mm in thickness. Two groups were made for each material containing 10 discs; G1/G2 (vitofil), G3/G4 (vitremere), G5/G6 (Filtek Z350). After 24 hours, the discs were polished. Group 1, group 3 and group 5 were immersed in red bull for 2 minutes during whole expereiment. Group 2, group 4 and group 6 were immersed in jolt cola for 2 minutes during whole expereiment. Microhardness test were performed in digital micro hardness tester before and after immersion at different time interval. The results were statistically analyzed with the help of two-way ANOVA with repeated measurement and Tukey’s test. RESULTS: According to time interval for vitofil and vitremere there is insignificant difference between baseline and day 1 surface micro hardness values (p>0.001). Significant difference is seen between baseline micro hardness and day 7 day 14,day 30 (p<0.001). Inverse is true for Filtek Z350 there is significant difference between base line and day 1 micro hardness values(p<0.001). The difference between base line, day 7, day 14 and day 30 is insignificant (p>0.001). According to immersion media there is insignificant difference between both of them (p>0.001). CONCLUSION: The effect of energy drinks on the surface micro hardness of a restorative material depends on the duration of contact time and the material composition not on the type of drink.

scholarly journals Effects of Toothbrushing with Fluoride Abrasive and Whitening Dentifrices on Both Unbleached and Bleached Human Enamel Surface in Terms of Roughness and Hardness: An in vitro Study

2012 ◽  
Vol 13 (5) ◽  
pp. 584-589 ◽  
Author(s):  
Sukran Bolay ◽  
Filiz Yalcin Cakir ◽  
Sevil Gurgan
Keyword(s):  
Surface Roughness ◽  
In Vitro Study ◽  
Vitro Study ◽  
Enamel Surface ◽  
Carbamide Peroxide ◽  
Hardness Tester ◽  
Human Enamel ◽  
Machine Surface Roughness ◽  
Hardness Values

ABSTRACT Aim The aim of this in vitro study was to evaluate the surface roughness and hardness of both unbleached and bleached (opalescence; 10% carbamide peroxide) human enamel brushed with water (without dentifrice), fluoride abrasive dentifrice (Colgate Total) and whitening dentifrice (Natural White). Materials and methods Human enamel samples were obtained from third molars and randomly divided into five groups (n = 8): G1—Control (brushed with water without dentifrice), G2—Colgate Total (fluoride abrasive dentifrice), G3—Natural White (whitening dentifrice), G4—Opalescence (10% carbamide peroxide) and then brushed with Colgate Total, G5— Opalescence (10% carbamide peroxide) and then brushed with Natural White. Bleaching regimen was applied according to manufacturers’ instructions. The brushing process was performed with a modified Nyffenegger's brushing machine. Surface roughness was analyzed with a profilometer. Microhardness testing was performed with a Brinell hardness tester. Results Results were statistically analyzed by Kruskal-Wallis, one-way ANOVA analysis and Mann-Whitney U, Wilcoxon matched-pairs signed-ranks tests. There were significant differences in surface roughness values for all groups, which showed an increase in roughness (p < 0.05). When the bleaching treatment combined with brushing with whitening dentifrice was performed (G5), there was a significant decrease in hardness values (p < 0.05). The other groups (G1, G2, G3, G4) showed no significant hardness differences (p > 0.05). Conclusion It was concluded that toothbrushing procedures increased the enamel surface roughness, and that bleaching regimen performed with cleaning treatment, through brushing with whitening dentifrice decreased hardness values. Clinical significance When applied together, bleaching and cleaning treatments may alter the enamel surface roughness and hardness values. How to cite this article Bolay S, Cakir FY, Gurgan S. Effects of Toothbrushing with Fluoride Abrasive and Whitening Dentifrices on Both Unbleached and Bleached Human Enamel Surface in Terms of Roughness and Hardness: An in vitro Study. J Contemp Dent Pract 2012;13(5):584-589.

An Experimental Study on the Properties of Fe-Based Amorphous Composite Coatings Prepared by Different Processes

2011 ◽  
Vol 239-242 ◽  
pp. 2137-2141 ◽  
Author(s):  
De Juan Xie ◽  
Zong De Liu ◽  
Wei Qiang Hu ◽  
Yong Tian Wang
Keyword(s):  
Composite Coatings ◽  
Arc Spraying ◽  
Water Cooling ◽  
Micro Hardness ◽  
Laser Remelting ◽  
Structure Defects ◽  
Hardness Tester ◽  
Metallurgical Bonding ◽  
Average Grain Size ◽  
Hardness Values

Fe-based amorphous composite coatings were deposited on the surface of ASTM-1020 steel plate by different technologies: arc spraying, laser remelting, TIG remelting (with and without water cooling). The microstructure, phase structure and micro-hardness were characterized by using a combination of SEM, XRD and Vickers hardness tester. It shows that the coating prepared by arc spraying presents typical lamellar structure and poor adherence to the substrate. After the remelting treatment, the coating quality is significantly improved by decreasing structure defects such as cracks and pores; the interface shows the metallurgical bonding. The dendritic crystals could be obtained within all the remelted coatings with different appearances. The microstructures of TIG remelted coatings show much more regular and have obvious orientation, which cannot be seen in laser remelted coating. However, the average grain size of the laser remelted coating is much smaller than that of TIG remelted coatings. The micro-hardness values of all of the deposited coatings are much higher than that of the substrate, and the coating prepared by laser remelting shows the highest hardness.

scholarly journals An in vitro Comparison of Marginal Accuracy in Temporary Crowns

2013 ◽  
Vol 3 (3) ◽  
pp. 121-126 ◽  
Author(s):  
Fahad Umer ◽  
Samira Adnan ◽  
Farhan Raza Khan
Keyword(s):  
Computer Software ◽  
Marginal Gap ◽  
Luting Cement ◽  
Marginal Discrepancy ◽  
The Mean ◽  
Post Hoc ◽  
To Receive ◽  
Mandibular First Molar ◽  
One Way Anova

ABSTRACT Purpose To compare the marginal accuracy of temporary crowns in vitro, using two autopolymerizing temporary crown materials. Materials and Methods Polyethyl methacrylate and bis-acryl composite were used to make 15 temporary crowns each, on an ivorine mandibular first molar, prepared as to receive a porcelain-fused-to-metal (PFM) crown. Matrices were made of polyvinyl siloxane impressions of a lower typodont arch. After crowns were fabricated, margins of the crowns were trimmed under magnification. Afterwards, margins of prepared tooth and crowns were marked. Each tooth-crown assembly was then observed under microscope (4×). With digital images of each surface, gap between margins of crown and preparation margin was measured in millimeters using computer software, after calibration. Two examiners made the measurements. Independent samples t-test and one-way ANOVA with Bonferroni post hoc analysis were applied to determine the mean marginal gap. Results Bis-acryl composite crowns exhibited 0.2 mm (SD ± 0.11) mean gap with greatest discrepancy at buccal margins. Mean gap with polyethyl methacrylate crowns was 0.3 mm (SD ± 0.17) with buccal and mesial margins exhibiting the greatest marginal discrepancy, at α <0.001. Conclusion Both materials did not exhibit ideal marginal accuracy, but temporary luting cement film thickness would compensate for the gap observed in the margins of bis-acryl composite crowns. How to cite this article Adnan S, Khan FR, Umer F. An in vitro Comparison of Marginal Accuracy in Temporary Crowns. J Contemp Dent 2013;3(3):121-126.

Evaluation of Load Parameters and Hold Time of a Vickers Ultra-Micro Hardness Tester for Measure of Hardness and Modulus of Elasticity of Dental Composites

2018 ◽  
Vol 912 ◽  
pp. 130-135 ◽  
Author(s):  
Tereza Cristina Favieri Melo-Silva ◽  
Cláudio Luis Melo-Silva ◽  
Cristiane Fonseca Carvalho ◽  
A.B. Teixeira ◽  
E.C. Carvalho ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Modulus Of Elasticity ◽  
Hybrid Composites ◽  
Hold Time ◽  
Dental Composites ◽  
Micro Hardness ◽  
Inorganic Particles ◽  
Hardness Tester ◽  
Vickers Indenter ◽  
Hardness Values

The aim of this study was to standardize the parameters for testing the hardness and elastic modulus for dental composites. It used the equipment Dynamic Ultra Micro Hardness Tester DUH-211 / DUH-211S (Shimadzu) varying the load and the hold time. two composites were used with various inorganic particles that were embedded and sanded for the assay. one Vickers indenter was used being held nine rows with ten penetrations. For each composite loads were used (20, 50 and 100gf) and times (zero, five and ten seconds). The results showed that the effect of the load and the hold time had influence on the modulus and hardness values of the studied composites. The authors concluded that loads and hold larger team showed greater stability of hardness values and modulus of elasticity for the studied composites and these values for both hybrid composites as for nanoparticulate were dependent on load and time.

scholarly journals Difference between post curing composite hardness with heating using dry sterilizer and radiation using light box

2010 ◽  
Vol 22 (2) ◽  
Author(s):  
Ratih Widyasari ◽  
Mochammad Richata Fadil ◽  
Endang Sukartini
Keyword(s):  
Composite Resin ◽  
Resin Composites ◽  
Hardness Tester ◽  
Long Time ◽  
Show Result ◽  
Curing Method ◽  
Composite Hardness ◽  
Post Hoc ◽  
Made In

Introduction: Composite resin has been used as a restoration material for quite a long time. Two different methods were expected to show result of which method that would be the most promising. Aim of study is to analyzed differences the hardness of one composite resin subjected to two post curing treatments. Methods: This study was a true experimental research (in vitro). The subjects were 30 specimens of the hybrid light cured resin composites made in a mold (6 mm diameter and 4 mm high). The hardness of all specimens were tested using Rebound Hardness Tester. Data were compared using ANOVA and post hoc analysis (for pairwise independent groups) using t-tests. Results: This study showed that post curing treatment by heat (for 10 min at 110 oC ) showed higher hardness (p<0.005). Conclusion: There was difference of hardness between two methods of post curing. Moreover, post curing with dry heat sterilizer at 110oC for 10 min was found to be the most promising post curing method.

scholarly journals Ceramic Surface Polishing Techniques After Removal of Orthodontic Adhesive

2009 ◽  
Vol 79 (4) ◽  
pp. 790-795 ◽  
Author(s):  
Adriana de Alcântara Cury-Saramago ◽  
Priscila Rocha Coimbra ◽  
Antonio de Moraes Izquierdo ◽  
Carlos Nelson Elias ◽  
Antônio Carlos de Oliveira Ruellas ◽  
...  
Keyword(s):  
Surface Preparation ◽  
Control Group ◽  
Ceramic Surface ◽  
Diamond Bur ◽  
Surface Polishing ◽  
Level Of Significance ◽  
Post Hoc ◽  
To Receive ◽  
Glazed Porcelain

Abstract Objective: Verify the in vitro effectiveness of different porcelain surface polishing systems used after orthodontic debonding. Materials and Methods: Restorations were simulated by 52 metallic samples covered with glazed feldspathic porcelain. Four of these intact samples composed the control group (C). The remaining samples were divided into four groups (n = 12), according to the surface preparation they were to receive: no surface treatment (G1); roughened with a diamond bur (G2); etched with 10% hydrofluoric acid (G3); and sandblasted with aluminum oxide (G4). All experimental samples were treated with silane and bonded with a primer and standardized amount of adhesive. After composite removal, each group was divided into subgroups randomly (n = 4), according to the porcelain polishing system used: Edenta (P1); Identoflex (P2); and Komet (P3). All 52 sample-surfaces were evaluated quantitatively with a profilometer, and a mean roughness profile (Ra) value was determined for each sample. Both control and experimental specimens were evaluated qualitatively using a scanning electron microscope (SEM) to assess surface morphology. Results: Statistical analysis with analysis of variance (ANOVA) and post-hoc Tukey multiple comparisons test showed statistical differences between surface preparation groups (G1 ≠ G2 = G3 = G4), at α = .05 level of significance; as for polishing protocols, no statistical difference was found. Conclusions: The surface preparation was the determinant for final surface texture. No combination between surface preparation and polishing system was able to reestablish the original glazed porcelain smoothness.

Sign in / Sign up

Export Citation Format

Share Document