scholarly journals Comparing the Effectiveness of Different Dentinal Desensitizing Agents: In Vitro Study

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Mohideen S. Farook ◽  
Okba Mahmoud ◽  
Maysara Adnan Ibrahim ◽  
Marwah Berkathullah
Keyword(s):  
Repeated Measures ◽  
Morphological Changes ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Fluid Filtration ◽  
Formula Group ◽  
Desensitizing Agents ◽  
Edx Analyses ◽  
Group 2

Objectives. To evaluate the in vitro effectiveness of desensitizing agents in reducing dentine permeability. Methods. The efficacy of desensitizing agents in reducing dentine permeability by occluding dentine tubules was evaluated using a fluid filtration device that conducts at 100 cmH2O (1.4 psi) pressure, and SEM/EDX analyses were evaluated and compared. Forty-two dentine discs ( n = 42 ) of 1 ± 0.2   mm width were obtained from caries-free permanent human molars. Thirty dentine discs ( n = 30 ) were randomly divided into 3 groups ( n = 10 ): Group 1: 2.7% wt. monopotassium-monohydrogen oxalate (Mp-Mh oxalate), Group 2: RMGI XT VAR, and Group 3: LIQ SiO2. Dentine permeability was measured following treatment application after 10 minutes, storage in artificial saliva after 10 minutes and 7 days, and citric acid challenge for 3 minutes. Data were analysed with a repeated measures ANOVA test. Dentine discs ( n = 12 ) were used for SEM/EDX analyses to acquire data on morphological changes on dentine surface and its mineral content after different stages of treatment. Results. Desensitizing agents’ application on the demineralized dentine discs exhibited significant reduction of permeability compared to its maximum acid permeability values. Mp-Mh oxalate showed a significant reduction in dentine permeability ( p < 0.05 ) when compared to RMGI XT VAR and LIQ SiO2. On SEM/EDX analysis, all the agents formed mineral precipitates that occluded the dentine tubules. Conclusions. 2.7% wt. monopotassium-monohydrogen oxalate was significantly effective in reducing dentine permeability compared to RMGI XT VAR and LIQ SiO2.

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

2018 ◽  
Vol 53 (3) ◽  
pp. 296-304 ◽  
Author(s):  
Lenita Marangoni-Lopes ◽  
Gabriela Rovai-Pavan ◽  
Carolina Steiner-Oliveira ◽  
Marinês Nobre-dos-Santos
Keyword(s):  
Primary Teeth ◽  
Morphological Changes ◽  
Artificial Saliva ◽  
Surface Hardness ◽  
In Vitro Study ◽  
Sem Analysis ◽  
Sem Images ◽  
Organic Composition ◽  
Nonnormal Distribution

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.

scholarly journals Axial Loads on Implant-Supported Partial Fixed Prostheses for External and Internal Hex Connections and Machined and Plastic Copings: Strain Gauge Analysis

2015 ◽  
Vol 41 (2) ◽  
pp. 149-154 ◽  
Author(s):  
Luis Gustavo Oliveira de Vasconcellos ◽  
Alberto Noriyuki Kojima ◽  
Renato Sussumu Nishioka ◽  
Luana Marotta Reis de Vasconcellos ◽  
Ivan Balducci
Keyword(s):  
Strain Gauge ◽  
Repeated Measures ◽  
Axial Loading ◽  
In Vitro Study ◽  
Chromium Alloy ◽  
Joint Loading ◽  
Cobalt Chromium ◽  
Implant Abutment ◽  
Group 2

The aim of this in vitro study was to use strain gauge (SG) analysis to compare the effects of the implant-abutment joint, the coping, and the location of load on strain distribution in the bone around implants supporting 3-unit fixed partial prostheses. Three external hexagon (EH) implants and 3 internal hexagon (IH) implants were inserted into 2 polyurethane blocks. Microunit abutments were screwed onto their respective implant groups. Machined cobalt-chromium copings and plastic copings were screwed onto the abutments, which received standard wax patterns. The wax patterns were cast in a cobalt-chromium alloy (n = 5): group 1 = EH/machined. group 2 = EH/plastic, group 3 = IH/machined, and group 4 = IH/plastic. Four SGs were bonded onto the surface of the block tangentially to the implants. Each metallic structure was screwed onto the abutments and an axial load of 30 kg was applied at 5 predetermined points. The magnitude of microstrain on each SG was recorded in units of microstrain (μɛ). The data were analyzed using 3-factor repeated measures analysis of variance and a Tukey test (α = 0.05). The results showed statistically significant differences for the type of implant-abutment joint, loading point, and interaction at the implant-abutment joint/loading point. The IH connection showed higher microstrain values than the EH connection. It was concluded that the type of coping did not interfere in the magnitude of microstrain, but the implant/abutment joint and axial loading location influenced this magnitude.

scholarly journals Evaluation of degradation of force of esthetic elastomeric chains

2019 ◽  
Vol 48 ◽  
Author(s):  
Mayra Teixeira Cortat LUCINDO ◽  
Diego Patrik Alves CARNEIRO ◽  
Felipe Alexandre de SOUZA ◽  
Américo Bortolazzo CORRER ◽  
Heloisa Cristina VALDRIGHI
Keyword(s):  
Repeated Measures ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Time Interval ◽  
Test Machine ◽  
Reduction In Force ◽  
Original Length ◽  
The Aesthetic ◽  
Elastomeric Chains

Abstract Introduction Elastomers are considered important allies to orthodontic treatment and due to the aesthetic demand, aesthetic elastomers are increasingly used in adult patients. Objective The aim of this experimental in vitro study was to evaluate the degradation of force of esthetic elastomeric chains, of three different sizes: short, medium and long. Material and method For evaluating the degradation of force, 90 elastomeric chain segments were used, divided into 9 Groups (n=10), as follows: Morelli short elastomer, Morelli medium, Morelli long, Orthometric short, Orthometric medium, Orthometric long, American Orthodontic short, American Orthodontic medium and American Orthodontic long. Acrylic plates with pins were used to provide stretching of the elastomeric chains. The initial stretching force of the elastomeric chain was 150 grams, measured by a tensiometer. After this, they were prestretched to 50% of their original length, measured in an Instron 4411 Universal test machine, and placed on the seating pin on the plate. The plate was immersed in artificial saliva at 37 °C in a plastic receptacle, and removed for measurement after a time interval of 21 days. For statistical analysis, the methodology of mixed models for repeated measures in time and Tukey-Kramer test were used. Degradation of the forces was analyzed by 2-way analysis of variance (ANOVA) and the Tukey test. Result All the elastomeric chains showed statistically significant reduction in force (p<0.05). The American Orthodontic elastomeric chains showed higher reduction in force values, irrespective of the elastic size (p<0.05). Conclusion The three commercial brands studied underwent significant reduction in the quantity of force released; the American Orthodontic brand of elastomer showed the highest value of degradation in force.

scholarly journals The Effectiveness of Remineralizing Agents on Dentinal Permeability

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Marwah Berkathullah ◽  
Mohideen S. Farook ◽  
Okba Mahmoud
Keyword(s):  
Repeated Measures ◽  
Artificial Saliva ◽  
Fluid Filtration ◽  
Treatment Agent ◽  
Group 5 ◽  
Group 2 ◽  
Dual Mechanism ◽  
Tooth Mousse ◽  
Treatment Application ◽  
Acid Challenge

The effectiveness of remineralizing agents in reducing dentine permeability by tubule occlusion using fluid filtration device functioning at 100 cmH2O (1.4 psi) pressure and SEM/EDX analysis were evaluated and compared. Seventy (n = 70) dentine discs of 1±0.2 mm width were prepared from sound permanent human molars. Fifty (n = 50) dentine discs were randomly divided into 5 groups (n = 10): Group 1: GC Tooth Mousse Plus (Recaldent GC Corporation Tokyo, Japan), Group 2: Clinpro™ White Varnish (3M ESPE, USA), Group 3: Duraphat® Varnish (Pharbil Waltrop GmbH, Germany), Group 4: Colgate Sensitive Pro-Relief™ dentifrice (Colgate Palmolive, Thailand), and Group 5: Biodentine™ (Septodont/UK). Dentine permeability was measured after treatment application at 10 minutes, artificial saliva immersion at 7 days, and citric acid challenge for 3 minutes. Data were analyzed by two-way repeated measures ANOVA. Dentine specimens (n = 20) were used for SEM/EDX analyses to obtain qualitative results on dentine morphology and surface deposits. Each treatment agent significantly reduced dentine permeability immediately after treatment application and created precipitates on treated dentine surfaces. All agents increased permeability values after 7 days of artificial saliva immersion except Clinpro White Varnish and Biodentine. Clinpro White Varnish exhibited significant resistance to acid challenge compared to others. Colgate Sensitive Pro-Relief dentifrice has a dual mechanism of action in reducing the dentine sensitivity.

Tooth Whitening Effect of Toothpastes Containing Nano-Hydroxyapatite

2006 ◽  
Vol 309-311 ◽  
pp. 541-544 ◽  
Author(s):  
B.I. Kim ◽  
S. H. Jeong ◽  
S.O. Jang ◽  
Kyoung Nam Kim ◽  
H.K. Kwon ◽  
...  
Keyword(s):  
Artificial Saliva ◽  
In Vitro Study ◽  
Tooth Brushing ◽  
Tooth Whitening ◽  
Whitening Effect ◽  
Before And After ◽  
Group 2 ◽  
Surface Dimension

The aim of this in vitro study was to evaluate the tooth whitening effect of toothpaste containing nano-sized hydroxyapatite (HA). There were 3 types of dentifrices, which had a different level of abrasive components. For group 1, a newly developed toothpaste containing Nano-sized hydroxyapatite (Nano-HA) was used. Commercially available toothpastes were used in groups 2 and 3. Group 2 used toothpastes containing silica and multi phosphate. Group 3 used toothpastes containing abrasives with silica and micro-sized HA. In order to simulate 6-months of tooth brushing, the tooth specimens in all 3 groups were placed on a V8 Cross Brushing Machine (Sabri Co. U.S.A.) and brushed 10,000 times with the toothpaste slurries. The tooth specimens were then soaked in artificial saliva for 24 hours to create conditions similar to those encountered in vivo. The whitening efficacy was assessed before and after tooth brushing using the VITA shade scores of Shadeeye-EX NCC Dental Chroma meter (Shofu Co. Japan). All toothpastes produced significant differences in the mean shade change in the teeth before and after tooth brushing (p<0.05). However, there were no significant differences in the change in the shade between each group (p>0.05). Although the new Nano-HA toothpaste did not have superior whitening effects to the commercially available whitening toothpastes, they had a similar whitening efficacy to commercially available whitening toothpastes. These effects might come from the physical properties of Nano HA, which increase the surface dimension more than the Micro-sized HA and have the potential of remineralization.

scholarly journals Comparison of shear bond strength and bonding time of a novel flash-free bonding system

2015 ◽  
Vol 86 (2) ◽  
pp. 265-270 ◽  
Author(s):  
Moonyoung Lee ◽  
Georgios Kanavakis
Keyword(s):  
Bond Strength ◽  
Repeated Measures ◽  
Shear Bond Strength ◽  
In Vitro Study ◽  
Bonding Time ◽  
Control Group ◽  
Bonding System ◽  
Manual Group ◽  
Group 2

ABSTRACT Objective:  To evaluate the bonding time, shear bond strength (SBS), and adhesive residue index (ARI) of APC(TM) Flash-Free bonding system. Materials and Methods:  Thirty-six extracted human maxillary premolars were randomly divided into three groups (12 per group) and used for this in vitro study: group 1, APC Flash-Free Adhesive Coated Appliance System; group 2, Clarity ADVANCED Ceramic Bracket pasted manually; group 3 (control group), 3M APC PLUS Adhesive prepasted brackets bonded with the extruded flash removed. Bonding time was measured using a stopwatch. Bond strength was measured using an Instron at a cross-head speed of 1 mm/min. The ARI was graded on a scale from 1 to 5. Repeated-measures analysis of variance and post hoc Tukey tests were used for statistical analysis. Results:  It took significantly (P &lt; .001) less time to bond in the APC Flash-Free Adhesive group (30.7 ± 3.3 seconds) compared with the control group (41.8 ± 4.0 seconds) and the manual group (39.2 ± 2.8 seconds). The APC Flash-Free Adhesive coated bracket had significantly (P &lt; .001) greater SBS (13.7 ± 2.2 MPa) compared with the control group (10.8 ± 2.0 MPa) and the manual group (10.4 ± 1.4 MPa). The ARI was significantly (P &lt; .001) greater with the APC Flash-Free Adhesive coated bracket compared with that of the other two groups. Conclusions:  Compared with other methods of bonding, the APC Flash-Free Adhesive Coated System can potentially reduce bonding time while increasing SBS.

scholarly journals Evaluation of Five Different Desensitizers: A Comparative Dentin Permeability and SEM Investigation In Vitro

2017 ◽  
Vol 11 (1) ◽  
pp. 15-33 ◽  
Author(s):  
Nasibe Aycan Yilmaz ◽  
Ertan Ertas ◽  
Hasan Orucoğlu
Keyword(s):  
Citric Acid ◽  
Morphological Changes ◽  
Artificial Saliva ◽  
Sem Analysis ◽  
Fluid Filtration ◽  
Dentin Permeability ◽  
Dentin Surface ◽  
The Difference ◽  
Self Etch

Background/Objective: The purpose of this study was to evaluate the efficacy and durability of five different dentin desensitizers (Gluma Desensitizer Powergel, Bifluorid 12, Gluma Self Etch Bond, D/Sense Crystal, Nupro Sensodyne Prophylaxis Paste with Novamin) on tubule occlusion and dentin permeability reduction in vitro. Method: The quantitative changes in permeability of 100 dentin discs were measured after desensitizer treatments and following post-treatments of 6% citric acid challenge for 1 min or immersion in artificial saliva for 24 hours under hydrostatic pressure generated by a computerised fluid filtration meter. Qualitative SEM analyses were also carried out. Results: Dentin permeability decreased after desensitizer application in all groups. Nevertheless, only the difference between ‘Gluma Self Etch Bond’ and ‘Nupro Sensodyne Prophylaxis Paste with Novamin’ groups was significantly different (p<0.05). Dentin permeability increased significantly after post-treatments (p<0.05). There was no statistically difference among the citric acid-subgroups (p>0.05). Of all the artificial saliva-subgroups, only the difference between ‘D/Sense Crystal’ and ‘Bifluorid 12’ was significantly different (p<0.05). In SEM analysis, morphological changes were detected on the dentin surface and within the tubules following desensitizer treatments and post-treatments. Conclusion: All the desensitizers significantly reduced dentin permeability by changing the morphology of the dentin surface and/or dentinal tubules. Following post-treatments, there was some reduction in the efficacy of the desensitizers which was represented by the reduction in permeability values. SEM analysis revealed some physical changes in the dentin structure which can partly give an explanation to the reduced efficacy of tested desensitizers.

Evaluation of Microleakage of Orthodontic Bands Cemented With CPP-ACP-Modified Glass Ionomer Cement

2019 ◽  
Vol 10 (2) ◽  
pp. 128-131
Author(s):  
Farzin Heravi ◽  
Hossein Bagheri ◽  
Abdolrasoul Rangrazi
Keyword(s):  
Glass Ionomer Cement ◽  
In Vitro Study ◽  
Glass Ionomer ◽  
Fluid Filtration ◽  
Filtration Method ◽  
Significant Difference ◽  
Patient Cooperation ◽  
Group 2 ◽  
Ionomer Cement

Aims and Objectives: In recent years, researchers have focused on finding methods of eliminating caries and white spot lesions under orthodontic bands without requiring patient cooperation. One of the effective and preventive strategies is the addition of antibacterial and remineralizing agents to the band cement. However, modifying the cement should not lead to microleakage and weakening of its mechanical properties. This in vitro study represents a continuation of our previous work of investigating the retentive strength of orthodontic bands cemented with casein phosphopeptide-amorphous calcium phosphate (CPP-ACP)-modified glass ionomer cement (GIC). Material and Methods: 60 extracted human premolars were randomly divided into two groups (n = 30). In group 1, stainless steel bands were cemented with GIC. In group 2, a novel dental caries-preventive material, CPP-ACP, was incorporated into the GIC for cementing. The microleakage of each group was measured by the fluid filtration method. Results: Results showed no statistically significant difference in microleakage of either group (GIC and CPP-ACP-modified GIC). Conclusion: We concluded that 1.56% w/w CPP-ACP can be incorporated with GIC for cementing orthodontic bands without promoting microleakage.

scholarly journals Effect of Previous Calcium Hydroxide Dressing on the Sealing Properties of the New Endodontic Cement Apical Barrier

2011 ◽  
Vol 05 (03) ◽  
pp. 260-264 ◽  
Author(s):  
Maryam Bidar ◽  
Reza Disfani ◽  
Salman Gharagozlo ◽  
Armita Rouhani ◽  
Maryam Forghani
Keyword(s):  
Calcium Hydroxide ◽  
In Vitro Study ◽  
Fluid Filtration ◽  
Filtration Method ◽  
Gutta Percha ◽  
Time Period ◽  
Significant Difference ◽  
Group 2 ◽  
Group 1

ABSTRACTObjectives: Using the fluid filtration method, an in vitro study was conducted to evaluate the effects of medication with calcium hydroxide on the sealing ability of the New Endodontic Cement (NEC) apical barrier in the short and long terms. Methods: Fifty extracted single rooted teeth were prepared and apical resorption produced using acid sulfuric for four days. The teeth were randomly divided into two experimental groups (n=20) and two control groups. In group 1, calcium hydroxide was placed into all canals for one week and in group 2, no medication was used. In both groups, a 4 mm NEC apical plug was placed in the canals and the remaining portion of the canals was filled with gutta-percha. The amount of microleakage of all samples was evaluated after one week and three months. The data were statistically analyzed using two-way ANOVA. Results: There was no significant difference between the two groups in either time period (P>.05). In both group 1 and group 2, microleakage increased after three months but this increase was not statistically significant (P>.05). Conclusions: According to the result of this study, medication with calcium hydroxide had no adverse effect on the short- and long-term sealing properties of an NEC apical plug. (Eur J Dent 2011;5:260-264)

scholarly journals Effect of Artificial Saliva Contamination on Bond Strength to Pulp Chamber Dentin

2008 ◽  
Vol 02 (02) ◽  
pp. 086-090 ◽  
Author(s):  
Hale Ară ◽  
Nazmiye Dönmez ◽  
Sema Belli
Keyword(s):  
Bond Strength ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Adhesive System ◽  
Control Group ◽  
Pulp Chamber ◽  
Significant Difference ◽  
Group 2 ◽  
Saliva Contamination

ABSTRACTObjectives: The purpose of this in vitro study was to evaluate the effect of artificial saliva contamination on microtensile bond strength to pulp chamber dentin.Methods: Clearfil SE Bond (SEB) (Kuraray, JAPAN) adhesive system and Clearfil Photo Posterior (CPP) (Kuraray, JAPAN) composite resin were used. Twenty extracted caries-free human molar teeth were randomly distributed into four groups. Apart from a control group without contamination (Group 1), primed dentin surfaces were contaminated with artificial saliva (10 s), rinsed, dried, reprimed and bonded (Group 2), coated with adhesive, contaminated with artificial saliva, rinsed, dried, bonding procedures were repeated (Group 3), coated with adhesive, light cured, contaminated with saliva, rinsed, dried, treated with SE primer (SEP) and SEB (Group 4).After 24 hrs, the teeth were prepared for microtensile bond testing and tensile bond strength was measured (1mm/min). The data was calculated as MPa and analyzed using one-way ANOVA and Duncan test (P<.05).Results: The results indicated that Group 2 showed lowest bond strength when compared to the others (P<.05). No statistically significant difference was found between Groups 3 and 4 (P>.05).Conclusions: It was concluded that contamination during priming procedure has a negative effect on bond strength (P<.05). Although contamination of the uncured adhesive was not critical in this study (P>.05) any kind of contamination of the bonding area should, in principle, be avoided. (Eur J Dent 2008;2:86-90)

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