scholarly journals Effect of different EGTA concentrations on dentin microhardness

2002 ◽  
Vol 13 (3) ◽  
pp. 188-190 ◽  
Author(s):  
Antonio Miranda da Cruz-Filho ◽  
Eduardo Augusto de Paula ◽  
Jesus Djalma Pécora ◽  
Manoel Damião de Sousa-Neto
Keyword(s):  
Acetic Acid ◽  
Statistical Analysis ◽  
High Speed ◽  
Acrylic Resin ◽  
Distilled Water ◽  
Three Solutions ◽  
Human Teeth ◽  
Tukey Test ◽  
Significant Difference ◽  
Root Dentin

The effect of 1%, 3% and 5% EGTA (ethylene glycol-bis-(b-amino-ethyl ether) N,N,N´,N´-tetra-acetic acid) on the microhardness of root dentin of the cervical third of human teeth was studied. Five newly extracted maxillary incisors were sectioned transversely at the cementoenamel junction, and the crowns were discarded. The roots were embedded in blocks of high-speed polymerized acrylic resin and cut transversely into 1-mm sections. The second section of the cervical third of the root of each tooth was sectioned and divided into four parts. Each part was placed on an acrylic disc that was used as a base for microhardness measurement. Fifty microliters of 1% EGTA, 3% EGTA, or 5% EGTA were applied to the dentin surface. Deionized and distilled water was used as control. Dentin microhardness was then measured with a load of 50 g for 15 s. Statistical analysis showed that the three concentrations of the chelating solution EGTA significantly reduced dentin microhardness when compared with water (ANOVA, p<0.01), and that there was a statistically significant difference among the three solutions (Tukey test, p<0.05).

scholarly journals Chitosan: effect of a new chelating agent on the microhardness of root dentin

2012 ◽  
Vol 23 (3) ◽  
pp. 212-217 ◽  
Author(s):  
Josilaine Amaral Pimenta ◽  
Danilo Zaparolli ◽  
Jesus Djalma Pécora ◽  
Antonio Miranda Cruz-Filho
Keyword(s):  
Citric Acid ◽  
Chelating Agent ◽  
Acrylic Resin ◽  
Knoop Hardness ◽  
Distilled Water ◽  
Water Control ◽  
Three Solutions ◽  
All Solutions ◽  
Root Dentin ◽  
One Way Anova

The effect of solutions of 0.2% chitosan, 15% EDTA and 10% citric acid on the microhardness of root dentin was evaluated comparatively in this study. Thirteen sound human maxillary central incisors were selected and decoronated at the cementoenamel junction. Ten roots were set into rapid polymerization acrylic resin and the root/resin block was fitted to the cutting machine to obtain slices from the cervical third. The first slice was discarded and the second slice was divided into four quadrants. Each quadrant was used to construct a sample, so that 4 specimens were obtained from each root slice, being one for each chelating solution to be tested: 15% EDTA, 10% citric acid, 0.2% chitosan and distilled water (control). The specimens were exposed to 50 μL of the solution for 5 min, and then washed in distilled water. A microhardness tester (Knoop hardness) with a 10 g load was used for 15 s. Data were analyzed statistically by one-way ANOVA and Tukey-Kramer test (α=0.05). The other 3 roots had the canals instrumented and irrigated at the end of the biomechanical preparation with the test solutions, and then examined by scanning electron microscopy (SEM) for qualitative analysis. All solutions reduced the microhardness of root dentin in a way that was statistically similar to each other (p>0.05) but significantly different from the control (p>0.05). The SEM micrographs showed that the three solutions removed smear layer from the middle third of the root canal. In conclusion, 0.2% chitosan, 15% EDTA and 10% citric acid showed similar effects in reducing dentin microhardness.

scholarly journals Effect of Gamma Radiation and Endodontic Treatment on Mechanical Properties of Human and Bovine Root Dentin

2016 ◽  
Vol 27 (6) ◽  
pp. 670-674 ◽  
Author(s):  
Veridiana Resende Novais ◽  
Priscilla Barbosa Ferreira Soares ◽  
Carlla Martins Guimarães ◽  
Laís Rani Sales Oliveira Schliebe ◽  
Stella Sueli Lourenço Braga ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Gamma Radiation ◽  
Hardness Test ◽  
Knoop Hardness ◽  
Endodontic Treatment ◽  
Bending Test ◽  
Human Teeth ◽  
Significant Difference ◽  
Root Dentin

Abstract This study evaluated the effect of gamma radiation and endodontic treatment on the microhardness and flexural strength of human and bovine root dentin. Forty single-rooted human teeth and forty bovine incisor teeth were collected, cleaned and stored in distilled water at 4 °C. The human and bovine teeth were divided into 4 groups (n=10) resulting from the combination of two study factors: first, regarding the endodontic treatment in 2 levels: with or without endodontic treatment; and second, radiotherapy in two levels: with or without radiotherapy by 60 Gy of Co-60 gamma radiation fractioned into 2 Gy daily doses five days per week. Each tooth was longitudinally sectioned in two parts; one-half was used for the three-point bending test and the other for the Knoop hardness test (KHN). Data were analyzed by 3-way ANOVA and Tukey HSD test (α=0.05). No significant difference was found for flexural strength values. The human dentin had significantly higher KHN than the bovine. The endodontic treatment and radiotherapy resulted in significantly lower KHN irrespective of tooth origin. The results indicated that the radiotherapy had deleterious effects on the microhardness of human and bovine dentin and this effect is increased by the interaction with endodontic therapy. The endodontic treatment adds additional negative effect on the mechanical properties of radiated tooth dentin; the restorative protocols should be designed taking into account this effect.

scholarly journals Ekstrak bonggol nanas cayenne menghambat pertumbuhan Candida albicans pada plat resin akrilik heat curing Hump extract of cayenne pineapple inhibit the growth of Candida albicans on heat cured acrylic resin plate

2013 ◽  
Vol 12 (2) ◽  
pp. 86
Author(s):  
Prizka Brigitasari ◽  
Moh. Dharmautama
Keyword(s):  
Candida Albicans ◽  
Acrylic Resin ◽  
Negative Control ◽  
Distilled Water ◽  
Traditional Medicines ◽  
Heat Curing ◽  
Significant Difference ◽  
Protein Molecules ◽  
Complex Protein ◽  
The Media

Hump of pineapple is one of traditional medicines found in Indonesia, containing many enzyme bromelains that canparse complex protein molecules into simpler compounds. The enzyme bromelain can inhibit the growth of Candidaalbicans. The increasing of colonies of C.albicans could be due to the increased use of denture. This study shouldexplore effectiveness of hump concentration of cayenne pineapple against C.albicans growth at 30 heat curing acrylicresin plates sized 10 x 10 x 2 mm. The plates immersed in 10 ml of C.albicans and incubated for 24 hours at 37°C. Theplates were divided into 6 groups, subsequently 5 acrylic resin plates, which were soaked for 8 hours at roomtemperature in an hump extract of cayenne pineapple with the concentration of 5%, 15%, 25%, 35%, and 45%.Negative control was soaked in distilled water. 0.01 ml of a 10-3dilution and dropped into the media sabouraunddextrose agar (SDA), and then incubated for 48 hours at 37°C, and counted the number of C.albicans colonies. Analyzed with ANOVA and LSD test, it was known a significant difference of hump extract of cayenne pineapple 5%,15%, 25%, 35%, and 45% against C.albicans growth (p <0,05). On from this fact, it was concluded that hump extractof cayenne pineapple can inhibit the growth of C.albicans, which is effective at a concentration of at least 15%.

scholarly journals Effect of citric acid irrigation on the fracture resistance of endodontically treated roots

2014 ◽  
Vol 08 (01) ◽  
pp. 074-078 ◽  
Author(s):  
Hakan Arslan ◽  
Cagatay Barutcigil ◽  
Ertugrul Karatas ◽  
Huseyin Sinan Topcuoglu ◽  
Kubra Yesildal Yeter ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Citric Acid ◽  
Fracture Resistance ◽  
Strength Test ◽  
Distilled Water ◽  
Root Fracture ◽  
Acid Irrigation ◽  
Significant Difference ◽  
Mandibular Incisors

ABSTRACT Objective: The aim of this study was to evaluate the effect of citric acid irrigation on root fracture in different concentrations and at various time exposures on root fracture. Materials and Methods: Forty-eight human mandibular incisors with similar dimensions were selected. The specimens were decoronated, then divided into 6 groups as follows: A group without instrumentation and filling (G1) and the 5 other groups with canal preparation and irrigation of distilled water (G2), 10% citric acid for 1 min (G3), 50% citric acid for 1 min (G4), 10% citric acid for 10 min (G5), and 50% citric acid for 10 min (G6). In the experimental groups, the canals were obturated and subjected to the strength test. Statistical analysis was performed using Kruskal-Wallis test (P = 0.05). Results: G6 showed the highest fracture resistance (629.97 N), and G3 showed the lowest fracture resistance (507.76 N). However, there was no statistically significant difference among the groups. Conclusions: The results of this study suggest that use of citric acid is safe in terms of fracture resistance.

scholarly journals Effect of the action of diamond burs with high speed on the tensile strength of cores cemented with zinc phosphate at different preparation times

2015 ◽  
Vol 63 (4) ◽  
pp. 405-410
Author(s):  
Vanilde Rocha Rodrigues
Keyword(s):  
Tensile Strength ◽  
Statistical Analysis ◽  
High Speed ◽  
Zinc Phosphate ◽  
Metallic Core ◽  
The Core ◽  
Significant Difference ◽  
To Receive ◽  
Cobalt Chrome Alloy ◽  
Cobalt Chrome

Objective: To know the finishing effect, in order to be able to safely proceed with the cores preparation in the daily clinic, without compromising the prosthetic restoration longevity. Methods: This study used 48 human single-rooted premolars, which after the section of its crowns, were endodontically treated, and its root canal prepared 8 mm deep to receive cores casting in cobalt-chrome alloy. Cementing was made with zinc phosphate and the tensile test performed at different preparation times: G1 - without re-preparation after cementation (control); G2 - re-prepared 24 hours after cementation, and G3 - re-prepared 15 minutes after cementation. Results: Statistical analysis showed no significant difference in the tensile strength values in the different groups (p = 0.233), in other words, the core re-preparation 15 minutes or 24 hours after the cementation caused no significant reduction in tensile strength between the core and the root remaining when using the zinc phosphate cement. Conclusion: The metallic core re-preparation cast 15 minutes or 24 hours after cementation caused no significant reduction in tensile strength between the cast metallic core and the root remaining, although in absolute values there was an important difference.

scholarly journals Prothrombase—Its preparation and properties

1930 ◽  
Vol 107 (751) ◽  
pp. 271-285 ◽  
Keyword(s):  
Acetic Acid ◽  
Isoelectric Point ◽  
High Speed ◽  
Tissue Extract ◽  
Distilled Water ◽  
Compact Mass ◽  
Coagulation Process ◽  
Mammalian Blood ◽  
The Way

An attempt to reconcile the various hypotheses which have been advanced to account for the phenomena observed in the coagulation of blood necessitated the isolation from blood of those substances which are primarily involved in the coagulation process. In this paper the preparation of prothrombase from oxalated mammalian blood is described and the conditions under which it is converted into thrombase—the enzyme which converts fibrinogen into fibrin—are considered. In 1909 I described a method by which a solution of prothrombase may be obtained from bird's blood. Noncoagulable plasma is obtained from a fasting anæsthetised cockerel in the way described by Delezenne (1897). This plasma is diluted with 10 volumes of distilled water and brought to the isoelectric point for globulin by the cautions addition of acetic acid (1 per cent.). The precipitated golbulin is obtained as a compact mass by spinning the diluted plasma in a high-speed centrifuge. It is suspended in a volume of water equal to that of the original plasma and dissolved by the addition NaCl to the extent of 0·7 per cent. This solution contains prothrombase associated with fibrinogen. The addition to it of a little tissue extract (thrombokinase), and CaCl 2 to the extent 0·05 per cent. causes, within a few minutes, the formation of a solid coagulum of fibrin. The residual fluid, obtained after the removal of the fibrin, contains a large quantity of thrombase. If however, a small quantity of thrombase be added to the original fibrinogen-prothrombase solution coagulation takes place within a few seconds and the residual fluid, after removal of the fibrin, contains a large quantity of prothombase. The properties of avian prothrombase contained in such a solution were described. No attempt was made to isolate the prothrombase owing to the difficulty of obtaining stable noncoagulable birds' in large quantities.

scholarly journals IN VITRO STUDY ON MARGINAL MICROLEAKAGE OF FOUR TEMPORARY CEMENTS IN PROVISIONAL CROWNS

2019 ◽  
Vol 3 (8) ◽  
Author(s):  
Dr. Ravi Nag ◽  
Dr. Jagjeet Singh ◽  
Dr. Abhilasha Masih Gottlieb ◽  
Dr. Ponnanna A. A. ◽  
Dr. Nikhil Verma ◽  
...  
Keyword(s):  
Zinc Phosphate ◽  
In Vitro Study ◽  
Acrylic Resin ◽  
Vitro Study ◽  
P Value ◽  
Chi Square ◽  
Human Teeth ◽  
Luting Cement ◽  
Significant Difference

Background: Prolonged retention of provisional restoration is depends upon the long term affinity between restoration and teeth structures which depend upon the use of good mechanical characteristics, low solubility, and superior adhesion  quality of luting cement which also resist bacterial and molecular penetration. Hence, assessment of marginal leakage of provisional restorative materials sealed with provisional cements using the standardized procedures is essential. Aim: This study aimed at in vitro study of microleakage of 4 provisional cements, a cavity base compound and a zinc-phosphate luting cement in provisional acrylic resin crowns fixed on extracted human teeth. Material & Methods:  The teeth with acrylic restorations were randomly divided into 6 groups of 6 specimens each. Each group received different types of temporary cement. Acrylic resin crowns were made and fitted on intact human premolars with the 4 cements. All restorations were applied in a standardized manner. Specimen were submerged in a 2% methylene blue solution, then sectioned and observed under a stereomicroscope for the detection of marginal microleakage. Obtained data were subjected to ANNOVA and Chi –square test to know statistical significant difference between different groups.  P value less than 0.05 was considered significant. Results and observation: Mean frequency of microleakage was statistically significant among all the groups under study with Pvalue<0.017. Conclusion: Among all the temporary cement, Zinc-phosphate cements has the best property with reduced microleakage. Even it is used as cavity base but can be used as good temporary cement as far as microleakage is concerned. Key words, Microleakage, provisional cement, restorations, crowns, in vitro

scholarly journals The Efficacy of High-Volume Evacuators and Extraoral Vacuum Aspirators in Reducing Aerosol and Droplet in Ultrasonic Scaling Procedures during the COVID-19 Pandemic

2022 ◽  
Author(s):  
Trijani Suwandi ◽  
Vidya Nursolihati ◽  
Mikha Sundjojo ◽  
Armelia Sari Widyarman
Keyword(s):  
Statistical Analysis ◽  
High Speed ◽  
High Volume ◽  
Limited Data ◽  
Dental Procedures ◽  
Significant Difference ◽  
Kolmogorov Smirnov ◽  
Airborne Disease ◽  
Better Than ◽  
Smirnov Test

Abstract Objective SARS-CoV-2 can be carried by aerosols and droplets produced during dental procedures, particularly by the use of high-speed handpieces, air-water syringes, and ultrasonic scalers. High-volume evacuators (HVEs) and extraoral vacuum aspirators (EOVAs) reduce such particles. However, there is limited data on their efficacy. This study aimed to determine the efficacy of HVE and EOVA in reducing aerosols and droplets during ultrasonic scaling procedures. Materials and Methods Three ultrasonic scaling simulations were conducted on mannequins: 1. saliva ejector (SE) was used alone (control); 2. SE was used in combination with HVE; and 3. SE was used in combination with HVE and EOVA. Paper filters were placed on the operator's and assistant's face shields and bodies, and the contamination of aerosols and droplets was measured by counting blue spots on the paper filters. Statistical Analysis All data were analyzed for normality using the Kolmogorov–Smirnov test. The differences between each method were analyzed using a two-way ANOVA, followed by a posthoc test. The differences were considered statistically significant when p < 0.05 Result Using HVE and EOVA reduced aerosols and droplets better than using SE alone or SE and HVE: the posthoc test for contamination revealed a significant difference (p < 0.01). The assistant was subjected to greater contamination than the operator during all three ultrasonic scaling procedures. Conclusion The usage of HVE and EOVA significantly reduced aerosols and droplets compared with using SE solely. Using these techniques together could prevent the transmission of airborne disease during dental cleanings, especially COVID-19. Further studies of aerosol-reducing devices are still needed to ensure the safety of dental workers and patients.

scholarly journals Effect of Final Irrigation Protocol on Dentin Microhardness

2018 ◽  
Vol 11 (4) ◽  
pp. 2157-2162
Author(s):  
Farah Salahalden Abbas ◽  
Nadeen Jamal Abdulredah ◽  
Amer Salman Hassan
Keyword(s):  
Citric Acid ◽  
Hardness Test ◽  
Acrylic Resin ◽  
Acid Group ◽  
Distilled Water ◽  
Mean Values ◽  
Canal Irrigation ◽  
Significant Difference ◽  
Group A ◽  
Group B

Endodontic therapy is essentially a debridement procedure that requires the removal of the irritants of the canal and periapical tissue if success is to be gained. The debridement may include instrumentation of the canal, placement of medicament and irrigants. Complete cleaning of the root-canal system requires the use of irrigants that dissolve organic and inorganic material. The study aimed to evaluate changes in dentin microhardness after canal irrigation with different solutions. Twenty four freshly extracted human mandibular molars (distal roots with single canals) were used. 10mm root length was taken as standard length. The roots were embedded into auto polymerizing acrylic resin using plastic molds before the canals preparation and micro hardness test. The distal roots were prepared with one shape rotary file. Before the preparation each root was irrigated with 1ml distilled water. Then the roots were divided into four groups according to the final irrigation protocol: Group A: NaOCl 2.5%, Group B: EDTA 17%, Group C: Citric Acid 40%, Group D: Distilled Water. For (Vicker microhardness test) the same load and time 500 g test load for 20 seconds, will be conducted three times at distance 0.5mm from canal lumen ; thus there will be 9 indentations on each specimen surface. An average of the three readings for each test condition will be recorded as the VHN value of a specimen. Comparing all four groups statistically there was no significant difference among them. The mean values were found more reduced in EDTA group followed by NaOCL group, and then Control and Citric Acid groups. All the groups showed reduction in dentin microhardness. EDTA group showed the maximum reduction followed by NaOCL group, and least with Citric Acid group.

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