Abrasivity of Desensitizing Dentifrice Containing Sodium Metasilicate

2007 ◽  
Vol 330-332 ◽  
pp. 1397-1400
Author(s):  
S.O. Jang ◽  
Su Young Lee ◽  
Hae Sun Kim ◽  
W.G. Chung ◽  
Kyoung Nam Kim ◽  
...  

This in vitro study compared the abrasivity of commercial desensitizing dentifrices with a sodium metasilicate (Na2SiO3) dentifrice using a Surface Profile Method. Dentin specimens were made from the root of extracted human molars. The cervical part of the teeth was sectioned with a diamond wheel disk. The teeth were embedded into an epoxy resin mold and the surface was gradually polished by silicone carbide paper. After grinding, the degree of surface roughness was tested within the range of 2 mm with tapping. The British Standard Institution reference dentifrice (BSI: CaCO3 40%) and experimental dentifrices (group 1: Na2SiO3 25%, CaCO3 10% and SiO2 10%, group 2: CaCO3 10% and SiO2 10%, group 3: CaCO3 10% and SrCl2 10%, group 4: Colloidal Silica 2-3% and Hydroxyapatite 10-20%) were evaluated. The dentifrice slurries were prepared by mixing 24 grams of the dentifrice in 12 ml distilled water. Each tooth specimen was brushed with the dentifrice slurries 1,000 times. The relative abrasivity of each dentifrice was evaluated from the ratio of the BSI standard dentifrice to each experiment. The results were analyzed by one-way ANOVA and Tukey’s multiple comparisons using Window SPSS (Statistical analysis system) 12.0. Groups 1 (71), 2 (74.2), 3 (38) and 4 (7.8) showed a lower abrasivity than the BSI dentifrice (100) (p<0.05). The relative abrasivity of groups 3 (38) and 4 (7.8) was the lowest compared with the BSI dentifrice (100). However, group 1 (71) containing Na2SiO3 showed a similar abrasivity to group 2 (74.2), which did not contain Na2SiO3 (p>0.05). Therefore, Na2SiO3 had no influence on the abrasivity of the dentifrice. In conclusion, the dentifrice containing Na2SiO3 had a lower abrasivity than the BSI reference dentifrice, but showed a significantly higher abrasivity than the existing commercial desensitizing dentifrices. Overall, the relatively high abrasivity of Na2SiO3 dentifrice is believed to be the result of other components in the abrasive system.

2007 ◽  
Vol 345-346 ◽  
pp. 773-776 ◽  
Author(s):  
S.O. Jang ◽  
S.Y. Lee ◽  
K.N. Kim ◽  
K.M. Kim ◽  
B.I. Kim

Carbonate apatite has a similar structure to the inorganic component of teeth and bone. Although carbonate apatite is widely used as a bone substitute, there are no reports on its use as a desensitizing dentifrice. This in vitro study evaluated the relative abrasivity of the dentifrice containing nano-sized carbonated apatite (n-CAPs) using a Surface Profile Method (SPM). The dentin specimens were made from the root of extracted human molars. The cervical part of the teeth was sectioned with a diamond wheel disk. The teeth were embedded into an epoxy resin mold and the surface was gradually polished using silicone carbide paper. After grinding, the degree of surface roughness was examined within the range of 2 mm with tapping. The British Standard Institution reference dentifrice (BSI: CaCO3 40%) and the experimental dentifrices (group 1: n-CAPs 30%, group 2: n-CAPs 15% and silica 15%, group 3: n-CAPs 5% and silica 25%, group 4: silica 30%, group 5: CaCO3 10% and SrCl2 10%) were compared. The dentifrice slurries were prepared by mixing 24 grams of the dentifrice in 12 ml distilled water. Each tooth specimen was brushed 1,000 times with the dentifrice slurries using a back-and-forth stroke. The relative abrasivity of each dentifrice was evaluated by determining the ratio of the BSI standard dentifrice to each experiment. The results were analyzed using one-way ANOVA and Tukey’s multiple comparisons using Window SPSS (Statistical analysis system) 12.0. According to the results, Group 1 (3.2), which contained only n-CAPs appeared to have the lowest abrasivity than the BSI dentifrice (100). However, Groups 2 (124.2), 3 (137.9) and 4 (178.1), which contained n-CAPs and silica, appeared to have a higher abrasivity than the BSI dentifrice (p>0.05). The relative abrasivity of group 5 (38), which was a commercial desensitizing dentifrice, was relatively lower. It appears that the higher abrasivity of the experimental is due to the shape and size of the silica component. Therefore, n-CAPs itself has no influence on the abrasivity of the dentifrice. The main reason for the low abrasivity of n-CAPs is believed to be its small particle size (range 50-90nm).


Author(s):  
Deebah Choudhary

Aim: The aim of this study was to evaluate the canal cleaning efficacy of these three file systems using scanning electron microscopy. Place and Duration of Study: The study was conducted in the Department of Conservative dentistry and Endodontics, Institute of Dental Sciences Sehora, between October 2020 and December 2020. Materials and Methods: Access cavity preparation was performed on sixty extracted human mandibular premolar teeth and working length was determined. The samples were randomly divided into three groups (n=20) depending upon the file system used i.e. Group 1 (Reciproc Blue), Group 2 (Waveone Gold) and Group 3 (F360). Samples were split into two halves by creating longitudinal grooves on the buccal and lingual surfaces. The samples were sputter-coated with gold and examined under scanning electron microscope at 5000X. The dentinal wall of root canal at coronal, middle and apical thirds of each sample were evaluated for the presence of determining the canal cleanliness and then analyzed using a five-score index. Results: The results of this study revealed that Group 1 (Reciproc Blue) exhibited better cleaning efficacy than samples of Group 2 (WaveOne Gold) and Group 3 (F360) at different locations in the canal i.e. coronal, middle and apical. The mean debris present was highest in coronal area for both group 2 and group 3 i.e. 2.1 and least was seen in apical area of group 1 i.e. 0.3. (p<0.05) Conclusion: Reciproc Blue single-file showed highest cleaning efficacy followed by Waveone Gold and F360. Reciproc file also showed effective cleaning in the apical third of the canal.


2020 ◽  
Vol 54 (4) ◽  
pp. 311-320
Author(s):  
Neeraj E Kolge ◽  
Vivek J Patni ◽  
Girish Karandikar ◽  
Ravindranath VK ◽  
Prateek Daga ◽  
...  

Aims & Objectives: The aim of the study was to evaluate and compare dimensional accuracy, surface characteristics and load deflection attributes of SS wires sourced from six different commercial houses. Materials & Methods: 0.019” x 0.025” SS wire samples were divided into 6 groups and evaluated and compared for the aforementioned properties. Dimensional accuracy, surface roughness, frictional resistance, load deflection rate and ultimate tensile strength were evaluated and compared. Results: Dimensional accuracy did not vary significantly. Surface Profilometry proved 3M Unitek (Group 1) to be the wire with least irregularities. According to SEM, Modern Orthodontics (Group 6) and 3M Unitek (Group 1) in terms of ‘Sa’ and ‘Sq’ respectively had the smoothest surface finish. SS wires sourced from G&H Orthodontics (Group 2) exhibited least frictional resistance. Load deflection rates varied for all the groups for all three parameters under the study. UTS was best for SS wires sourced from Rabbit Force Orthodontics (Group 5). Conclusion: No wire from a single commercial house excels in all the parameters that were evaluated, each one having its aces and minuses.


2014 ◽  
Vol 40 (1) ◽  
pp. 30-34 ◽  
Author(s):  
Simonetta D'Ercole ◽  
Antonio Scarano ◽  
Vittoria Perrotti ◽  
Jorge Mulatinho ◽  
Adriano Piattelli ◽  
...  

Prevention of microbial leakage at the implant-abutment junction is a major challenge for the construction of 2-stage implants in order to minimize inflammatory reactions and to maximize bone stability at the implant neck. The aim of the present in vitro study was an evaluation of the leakage observed over a period of 28 days in Cone Morse taper internal connections and in screwed-abutments connections. In the present study 10 specimens of Cone Morse (Group 1) and 10 of internal hexagon (Group 2) implants were used. The inner parts of 5 implants per group were inoculated with Pseudomonas aeruginosa (PS) suspension and 5 implants per group with Aggregatibacter actinomycetemcomitans (AA). The possible penetration of bacterial suspension into the surrounding solution was determined by the observation of turbidity of the broth. In Group 1, bacterial contamination was found in 3 out of 5 implant-abutment assemblies seeded with the PS and in 2 samples out of 5 in the assemblies seeded with AA, with a total of leaked assemblies in this group of 5 out of 10. In Group 2, bacterial contamination was found in 4 out of 5 implant-abutment assemblies seeded with the PS, and in 4 out of 5 samples seeded with AA, with a total of leaked assemblies of 8 out of 10. The present data confirm the reported high permeability to bacterial leakage of screw-retained abutment connections, and the lower infiltration rates—although not significantly—of Cone Morse taper internal connections.


2015 ◽  
Vol 5 (2) ◽  
pp. 65-68
Author(s):  
Shruti Patil ◽  
Prajna Shetty

ABSTRACT Background The dentin desensitizers available for in-office application for prevention and/or treatment of post restorative dentinal hypersensitivity, act by blocking the open dentinal tubules. In doing so, they may influence the bond strength of the restorative resins. Thus, the aim of the study was to evaluate the effect of desensitizers on the shear bond strength of dentin adhesives and to check the extent of dentinal tubule occlusion caused by these desensitizers. Materials and Methods Sixty-four premolars were randomly divided into four groups of sixteen each. The middle depth dentin was exposed by on the buccal surface and was etched using 37% phosphoric acid and rinsed. They were assigned to, Group 1: Gluma desensitizer, Group 2: Vivasens desensitizer, Group 3: Gluma Comfort Bond and desensitizer, and Group 4: Adper Single Bond 2. Composite resin post of 2 mm in height and width were built on these specimens. The samples were then mounted in acrylic resin blocks. Universal testing machine was used to test the shear bond strength. The data were analyzed using one-way analysis of variance (ANOVA) and post hoc Tukey's test. Results The mean values of the shear bond strength were for: Group 1—18.61 ± 1.03 MPa, Group 2—17.53 ± 1.36 MPa, Group 3—22.63 ± 1.61 MPa and Group 4—23.12 ± 1.02 MPa. There was a statistically significant difference (p < 0.05) among the groups. Conclusion The use of dentin desensitizers’ influences bond strength between the tooth and the adhesive. Among the various agents, the single bottle system containing Gluma comfort bond and desensitizer had the best adhesion among the desensitizer groups. How to cite this article Patil S, Naik B, Shetty P. A Comparative Evaluation of Three Commercially Available Dentin Desensitizers on the Shear Bond Strength of Composite Resins: An in vitro Study. J Contemp Dent 2015;5(2):65-68.


2019 ◽  
Vol 39 (1) ◽  
pp. 70-74
Author(s):  
Celeste B. Guimarães ◽  
Luciane Albuquerque ◽  
Marcela Torikachvili ◽  
Eduarda V. Vargas ◽  
Cecilia C. Dall’Agnol ◽  
...  

ABSTRACT: The aim of this study was to investigate the acute effects of atracurium besylate on cellular damage in corneal endothelium of chickens. Twenty healthy chicken eyes were assigned to the following groups: Group 1 (G1), experimental group (n=10); and Group 2 (G2), control (n=10). Excised corneoscleral buttons were immediately placed on glass microscopy slides with endothelial region faced up. Corneal endothelium of eyes in G1 were covered with AB (0.2mL, 10mg/mL) for 3 min and then rinsed with balanced salt solution (BSS), while the corneal endothelium of eyes in G2 were covered with BBS for 3 min. Corneas from both groups were stained with alizarin red/trypan blue and visualized by light microscopy. Ten random photographs were taken from each cornea. The area of cellular damage was measured by software in all samples and cell loss of each group was averaged and compared. Endothelial area of denudation and Descemet’s membrane exposure were higher in G1 than G2. In conclusion, atracurium besylate induced an acute damage on corneal endothelium of chickens.


2019 ◽  
Vol 64 (5) ◽  
pp. 555-562 ◽  
Author(s):  
Marie Kotthaus ◽  
Istabrak Hasan ◽  
Ludger Keilig ◽  
Manfred Grüner ◽  
Christoph Bourauel ◽  
...  

Abstract The aim of this study was to investigate the retention forces of secondary telescopic crowns made of polyetherketoneketone (PEKK) in combination with primary crowns made of four different dental alloys and to determine whether the retention forces change in the course of up to 5000 simulated wear cycles. A total of four groups of telescopic crowns were investigated: group 1: 10 primary crowns made of a gold alloy (NEOCAST®3), group 2: 10 primary crowns made of a non-precious metal alloy (Girobond NB), group 3: 10 primary crowns made of zirconium (Cercon®base) and group 4: 10 primary crowns made from PEKK (Pekkton®ivory). The corresponding secondary crowns were made from PEKK in all the four groups. Each pair was fixed axially in a wear simulator specifically designed for the study. Overall, 10,000 joining and separating cycles were performed for each group. To simulate intraoral conditions, a saliva substitute served as a lubricant. Force transducers were used to record the retention forces and after completing 10,000 cycles, the surface of each primary crown was examined using a scanning electron microscope (SEM). All groups showed an increase in the retention force for the first 2000 cycles which stayed constant for the remaining 8000 cycles. The Pekkton®ivory/Pekkton®ivory and NEOCAST®3/Pekkton®ivory combinations displayed mean retention force values of 16 N after a slight increase in the retention force. The Cercon®base/Pekkton®ivory and Girobond NB/Pekkton®ivory combinations displayed an initially high increase in the retention force and then showed a mean retention force of up to 29 N. All primary crowns displayed surface wear. Zirconium primary crowns showed the least wear compared to PEKK and the gold and non-precious metal alloys.


Author(s):  
Derivaldo Moura Gois Filho ◽  
Vanessa Tavares de Gois-Santos ◽  
Ronaldo Santos Silva ◽  
Antônio Carlos Marqueti ◽  
Arthur Rodriguez Gonzalez Cortes ◽  
...  

Introduction: The adaptation of prostheses fixed over implants involves biomechanical aspects that are directly associated with treatment success. Objective: The aim of this in vitro study was to evaluate the presence of microgaps in the abutment/inner connection interface of cone morse dental implants. Materials and methods: Two groups of implants were analyzed. The first group (n = 16) employed single-manufacturer dental implants and abutments, whereas the second group (n = 16) combined multi-manufacturer materials. The sets were analyzed through scanning electron mi­croscopy, wherein microgaps between the implant connection and the abutment were observed. Results: Group 1 had an average microgap of 5.69 μm (SD ± 8.46 μm). Group 2 had an average microgap of 1.24 μm (SD ± 0.44 μm). A significant difference was found between the two groups (p = 0.002). Conclusion: Within the limitations of this study, results suggest that the group formed by multi-manufacturer implants and abutments (group 2) had smaller microgap values, and, therefore, a higher in vitro adaptation of components. DESCRIPTORS | Dental Implants; Dental Abutments; Scanning Electron Microscopy.


2016 ◽  
pp. 28-32
Author(s):  
Xuan Anh Ngoc Ho ◽  
Thien Man Tran

Background: Overcoming the obstacles of Class II restoration, especially the microleakage, is a polemic issue. The present study was performed to evaluate the microleakage of Class II restorations using three different techniques. Aims: The aim of this in vitro study was to evaluate the microleakage of Class II restorations using three different techniques. Materials and methods: The study was carried out in the laboratory with paired comparision between groups. Thirty Class II cavities were prepared on extracted non-carious human permanent molars, randomly divided into 3 groups, which were then restored with 3 different methods. Group 1: indirect composite inlay (Tetric N-Ceram) cemented with resin-modified glass ionomer cement (Fuji Plus); Group 2 indirect composite inlay (Tetric N-Ceram) cemented flowable composite (Tetric N-flow); Group 3: direct composite restoration using Tetric N-Ceram. Before immersed to 2% methylene blue solution for 12 hours, all restorations were subjected to thermal cycling (100 cycles 50C – 55 0C). The extent of dye penetration along the gingival wall was assessed using a grade scale from 0 to 3 under 40 times magnification using digital camera Nikon D7000. Results: All types of restorations showed some rate of microleakage. In comparing the three techniques, group 1 demonstrated the significantly higher rate of leakage compared to the others (p<0.05), whereas group 2 and 3 showed no significant difference. Conclusion: Different luting materials have different influences on the microleakage degree along gingival wall of Class II restoration. Key word: composite inlay, class II restoration, microleakage


2018 ◽  
Vol 14 (2) ◽  
Author(s):  
K Licla

Objetive: To compare the microleakage of a resinsealant using fifth generation adhesive systems,seventh generation with or without preconditioningof orthophosphoric acid at 37%. Materials and Methods: An in vitro study wasmade on 60 human premolars, randomized into4 groups of 15 elements each. Group 1 (control):phosphoric acid at 37%, sealant; Group 2: orthophosphoricacid, adhesive of fifth generation, sealant; Group 3: adhesive of seventh generation,sealant; Group 4: orthophosphoric acid, adhesiveof seventh generation, sealant. They were puton a thermocycler, 500 cycles (5° y 55°C) per 30seconds on higher and lower temperatures, afterthat the specimens were drawn for 24 hours on1% methylene blue, cut off on a bucco-lingualway and evaluated on a stereomicroscope on 16x.Chi square test was used with a 0.05 significancelevel. Results: The greater percentage of microleakageshowed: control-adhesive without (53.3%), fifthgeneration (20%), the seventh generation (80%)and conditioning with orthophosphoric acid andadhesive seventh generation (67.7%). Conclusion: Microfiltration grade adhesivesealant fifth generation was lower than using theother adhesives.


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