scholarly journals A Comparative Study of Different Bleaching Agents on the Morphology of Human Enamel: An in vitro SEM Study

2012 ◽  
Vol 13 (6) ◽  
pp. 756-759 ◽  
Author(s):  
Roshan Uthappa ◽  
ML Suprith ◽  
Shreetha Bhandary ◽  
Sumit Dash
Keyword(s):  
Phosphoric Acid ◽  
Comparative Study ◽  
Tooth Enamel ◽  
Extended Period ◽  
Enamel Surface ◽  
Control Group ◽  
Human Enamel ◽  
Sem Study ◽  
Labial Surface

ABSTRACT The purpose of the study was to compare two different commercial bleaching agents, Opalescence with Colgate Platinum, and 30% phosphoric acid used as aggressive agent on the morphology of human enamel. Materials and methods Ten freshly extracted, noncarious, human maxillary central incisors extracted for periodontal reasons were used in this study. The labial surface of the disinfected teeth were polished using a polishing paste with the help of rubber cup and a slow speed handpiece. Each tooth was sectioned at cement-enamel junction and the crown was separated into four specimens, all taken from labial surface. Group 1 was treated with Colgate Platinum for 7 hours, group 2 with Opalescence for 7 hours, group 3 was treated with 30% phosphoric acid for 30 seconds and group 4 was untreated and used as control. After the treatment period, the specimens were washed with normal saline and stored in sterile bottle and sealed. Photomicrographs obtained from the scanning electron microscopy (SEM) after surface treatments were examined for no alteration, slight alteration, moderate alteration and severe alterations. Results The specimens treated with commercial bleaching agents revealed no enamel surface morphologic alterations compared to control group. The specimen treated with phosphoric acid showed severe alterations. Conclusion Ten percent carbamide peroxide evaluated in this study does not etch tooth enamel or alter enamel surface morphology as do conventional etching techniques. Clinical relevance Carbamine peroxide is a safe and effective tooth whitening agent even when used for extended period of time. The enamel surface remains smooth which reduces caries due to plaque collection. How to cite this article Uthappa R, Suprith ML, Bhandary S, Dash S. A Comparative Study of Different Bleaching Agents on the Morphology of Human Enamel: An in vitro SEM Study. J Contemp Dent Pract 2012;13(6):756-759.

scholarly journals Effect of a carbamide peroxide bleaching gel containing calcium or fluoride on human enamel surface microhardness

2005 ◽  
Vol 16 (2) ◽  
pp. 103-106 ◽  
Author(s):  
Rogério de Oliveira ◽  
Adriana Franco Paes Leme ◽  
Marcelo Giannini
Keyword(s):  
Artificial Saliva ◽  
In Vitro Study ◽  
Enamel Surface ◽  
Control Group ◽  
Carbamide Peroxide ◽  
Surface Microhardness ◽  
Treatment Groups ◽  
Peroxide Bleaching ◽  
Human Enamel

This in vitro study evaluated the surface microhardness of human enamel submitted to bleaching with 10% carbamide peroxide (CP) containing calcium or fluoride. Ninety-eight dental blocks (5 x 5 mm²) with polished enamel surfaces were randomly assigned to 7 treatment groups (n=14), as follows: without bleaching and storage in artificial saliva (control); 10% CP; 10% CP + 0.05% calcium; 10% CP + 0.1% calcium; 10% CP + 0.2% calcium; 10% CP + 0.2% fluoride; and 10% CP + 0.5% fluoride. During 14 days, enamel surfaces were daily exposed to a 6-h bleaching regimen followed by storage in artificial saliva. Surface microhardness was measured before (baseline), during (7th day), immediately after bleaching (14th day) and 1 week post bleaching. Data were analyzed by two-way ANOVA and Tukey's test (p<0.05). All treatments reduced SM significantly during the bleaching cycle (7th day), immediately after bleaching (14th day) and 1 week post bleaching, compared to baseline and to the unbleached control group. In conclusion, in spite of the addition of calcium and fluoride, all bleaching treatments affected the enamel surface microhardness.

scholarly journals Near-Surface Studies of the Changes to the Structure and Mechanical Properties of Human Enamel under the Action of Fluoride Varnish Containing CPP–ACP Compound

Biomolecules ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 765 ◽  
Author(s):  
Izabela Świetlicka ◽  
Damian Kuc ◽  
Michał Świetlicki ◽  
Marta Arczewska ◽  
Siemowit Muszyński ◽  
...  
Keyword(s):  
Group Treatment ◽  
In Vitro Study ◽  
Enamel Surface ◽  
Control Group ◽  
Near Surface ◽  
Molecular Arrangement ◽  
Human Enamel ◽  
Casein Phosphopeptides ◽  
Molar Teeth

Changes to the features of the enamel surface submitted to induced demineralisation and subsequent remineralisation were studied. The in vitro examination was conducted on polished slices of human molar teeth, divided in four groups: the untreated control (n = 20), challenged by a demineralisation with orthophosphoric acid (H3PO4) (n = 20), and challenged by a demineralisation following remineralisation with fluoride (F) varnish containing casein phosphopeptides (CPP) and amorphous calcium phosphate (ACP) compounds (n = 20). The specimens’ enamel surfaces were subjected to analysis of structure, molecular arrangement, mechanical features, chemical composition, and crystalline organization of apatite crystals. Specimens treated with acid showed a significant decrease in crystallinity, calcium, and phosphorus levels as well as mechanical parameters, with an increase in enamel surface roughness and degree of carbonates when compared to the control group. Treatment with fluoride CPP–ACP varnish provided great improvements in enamel arrangement, as the destroyed hydroxyapatite structure was largely rebuilt and the resulting enamel surface was characterised by greater regularity, higher molecular and structural organisation, and a smoother surface compared to the demineralised one. In conclusion, this in vitro study showed that fluoride CPP–ACP varnish, by improving enamel hardness and initiating the deposition of a new crystal layer, can be an effective remineralising agent for the treatment of damaged enamel.

Evaluation of Primary Tooth Enamel Surface Morphology and Microhardness after Nd: YAG Laser Irradiation and APF Gel Treatment—An in vitro study

2011 ◽  
Vol 35 (4) ◽  
pp. 377-382 ◽  
Author(s):  
Naveen Reddy Banda ◽  
Vanaja Reddy G ◽  
N Shashikiran
Keyword(s):  
Laser Irradiation ◽  
Tooth Enamel ◽  
Morphological Changes ◽  
Enamel Surface ◽  
Permanent Teeth ◽  
Primary Tooth ◽  
Control Group ◽  
Yag Laser ◽  
Fluoride Treatment

Objective: Laser irradiation and fluoride has been used as a preventive tool to combat dental caries in permanent teeth, but little has been done for primary teeth which are more prone to caries. The purpose of this study was to evaluate microhardness alterations in the primary tooth enamel after Nd-YAG laser irradiation alone and combined with topical fluoride treatment either before or after Nd-YAG laser irradiation.Method: Ten primary molars were sectioned and assigned randomly to: control group, Nd-YAG laser irradiation,Nd-YAG lasing before APF and APF followed by Nd-YAG lasing. The groups were evaluated for microhardness. Surface morphological changes were observed using SEM. Results: Statistical comparisons were performed. The control group's SEM showed a relatively smooth enamel surface and lasing group had fine cracks and porosities. In the lasing + fluoride group a homogenous confluent surface was seen. In the fluoride + lasing group an irregular contour with marked crack propagation was noted. There was a significant increase in the microhardness of the treatment groups. Conclusion: Nd-YAG laser irradiation and combined APF treatment of the primary tooth enamel gave morphologically hardened enamel surface which can be a protective barrier against a cariogenic attack

scholarly journals EROSIVE POTENTIAL OF SPORTS BEVERAGES ON HUMAN ENAMEL “IN VITRO”

2018 ◽  
Vol 24 (5) ◽  
pp. 386-390
Author(s):  
Dalila Meazza Damo ◽  
Guilherme Anziliero Arossi ◽  
Helena Alvez da Silva ◽  
Leonardo Haerter dos Santos ◽  
Diego Rafael Kappaun
Keyword(s):  
Vickers Microhardness ◽  
Tooth Enamel ◽  
Low Ph ◽  
Control Surface ◽  
Test Surface ◽  
Results Of Treatment ◽  
Sports Drinks ◽  
Human Enamel ◽  
The Mean

ABSTRACT Introduction: The low pH of sports drinks may cause tooth enamel demineralization. Objective: To measure Vickers hardness of human enamel exposed to sports drinks. Methods: Human molars were used to collect the enamel samples. Each sample had a test surface (exposed to the drinks) and a control surface (unexposed). The samples were exposed to isotonic drinks Gatorade and Powerade, and to maltodextrin drinks Malto Advanced and Malto Active, for 10 minutes every 12 hours over 30 days. The Vickers microhardness test was conducted with three indentations on each surface. The mean of the indentations within each group was considered in the statistical analysis. Sports drinks variables were analyzed with ANOVA/Tukey (p≤0.01). The independent t-test was used in the comparison between the control and test surfaces of each drink (p ≤ 0.05). Results: Enamel exposure to Gatorade (p = 0.000) Malto Advanced (p = 0.000) and Malto Active (p = 0.000) was seen to significantly reduce microhardness, while the isotonic drink Powerade had no significant effect on enamel (p = 0.248). Conclusion: It was concluded that with the exception of the isotonic drink Powerade, all the sports drinks tested caused a reduction in the microhardness of human enamel. Evidence Level III; Therapeutic studies - Investigating the Results of Treatment.

scholarly journals The Influence of Post Bleaching Treatments in Stain Absorption and Microhardness

2016 ◽  
Vol 10 (1) ◽  
pp. 69-78 ◽  
Author(s):  
Horieh Moosavi ◽  
Fatemeh Darvishzadeh
Keyword(s):  
Color Change ◽  
Enamel Surface ◽  
Control Group ◽  
Surface Microhardness ◽  
Dental Bleaching ◽  
Tooth Color ◽  
Group 4 ◽  
Group 3 ◽  
Group 2

Objectives: This study investigated the effects of post bleaching treatments to prevent restaining and the change of enamel surface microhardness after dental bleaching in vitro. Methods: Sixty intact human incisor teeth were stained in tea solution and randomly assigned into four groups (n=15). Then samples were bleached for two weeks (8 hours daily) by 15% carbamide peroxide. Tooth color was determined both with a spectrophotometer and visually before bleaching (T1) and immediately after bleaching (T2). Next, it was applied in group 1 fluoride (Naf 2%) gel for 2 minutes, and in group 2 a fractional CO2 laser (10 mJ, 200 Hz, 10 s), and in group 3, nanohydroxyapatite gel for 2 minutes. The bleached teeth in group 4 remained untreated (control group). Then teeth placed in tea solution again. Color examinations were repeated after various post bleaching treatments (T3) and restaining with tea (T4) and color change values recorded. The microhardness was measured at the enamel surface of samples. Data was analyzed using ANOVA, Tukey HSD test and Dunnett T3 (α = 0.05). Results: Directly after bleaching (ΔE T3-T2), the treatment with nanohydroxyapatite showed significantly the least color lapse in colorimetric evaluation. In experimental groups, the color change between T3 and T4 stages (ΔE T4-T3) was significantly lower than control group (P < 0.05). Different methods of enamel treatment caused a significant increase in surface microhardness compared to control group (P < 0.05). Significance: Application of fluoride, fractional CO2 laser and nanohydroxyapatite as post bleaching treatments are suggested for prevention of stain absorption and increasing the hardening of bleached enamel.

scholarly journals Effects of CO2laser irradiation on matrix-rich biofilm development formation–an in vitro study

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2458 ◽  
Author(s):  
Bruna Raquel Zancopé ◽  
Vanessa B. Dainezi ◽  
Marinês Nobre-dos-Santos ◽  
Sillas Duarte ◽  
Vanessa Pardi ◽  
...  
Keyword(s):  
Contact Angle ◽  
Biofilm Formation ◽  
Dental Enamel ◽  
In Vitro Study ◽  
Dry Weight ◽  
Vitro Study ◽  
Enamel Surface ◽  
Control Group ◽  
Biofilm Development

BackgroundA carbon dioxide (CO2) laser has been used to morphologically and chemically modify the dental enamel surface as well as to make it more resistant to demineralization. Despite a variety of experiments demonstrating the inhibitory effect of a CO2laser in reduce enamel demineralization, little is known about the effect of surface irradiated on bacterial growth. Thus, this in vitro study was preformed to evaluate the biofilm formation on enamel previously irradiated with a CO2laser (λ = 10.6 µM).MethodsFor this in vitro study, 96 specimens of bovine enamel were employed, which were divided into two groups (n = 48): 1) Control-non-irradiated surface and 2) Irradiated enamel surface. Biofilms were grown on the enamel specimens by one, three and five days under intermittent cariogenic condition in the irradiated and non-irradiated surface. In each assessment time, the biofilm were evaluated by dry weigh, counting the number of viable colonies and, in fifth day, were evaluated by polysaccharides analysis, quantitative real time Polymerase Chain Reaction (PCR) as well as by contact angle. In addition, the morphology of biofilms was characterized by fluorescence microscopy and field emission scanning electron microscopy (FESEM). Initially, the assumptions of equal variances and normal distribution of errors were conferred and the results are analyzed statistically by t-test and Mann Whitney test.ResultsThe mean of log CFU/mL obtained for the one-day biofilm evaluation showed that there is statistical difference between the experimental groups. When biofilms were exposed to the CO2laser, CFU/mL and CFU/dry weight in three day was reduced significantly compared with control group. The difference in the genes expression (Glucosyltransferases (gtfB) and Glucan-binding protein (gbpB)) and polysaccharides was not statically significant. Contact angle was increased relative to control when the surface was irradiated with the CO2laser. Similar morphology was also visible with both treatments; however, the irradiated group revealed evidence of melting and fusion in the specimens.ConclusionIn conclusion, CO2laser irradiation modifies the energy surface and disrupts the initial biofilm formation.

Etching Patterns of Sodium Hypochlorite Pretreated Hypocalcified Amelogenesis Imperfecta Primary Molars: SEM Study

2019 ◽  
Vol 43 (4) ◽  
pp. 257-262
Author(s):  
Amel Mahmoud Ahmed ◽  
Dina Nagy ◽  
Mona Abdallah Elkateb
Keyword(s):  
Phosphoric Acid ◽  
Sodium Hypochlorite ◽  
Amelogenesis Imperfecta ◽  
Acid Etching ◽  
Primary Molars ◽  
Control Group ◽  
Type I ◽  
Etching Pattern ◽  
Sem Study ◽  
Group Control Group

Aim: To investigate the etching patterns of hypocalcified amelogenesis imperfecta (AI) in primary molars pretreated with 5.25% NaOCl prior to phosphoric acid application using scanning electron microscopy (SEM). Study design: Ten hypocalcified AI primary molars were collected, sectioned longitudinally into 2 parts and allocated into two groups of ten specimens each. The enamel surface in the first group (control group) was etched using 37% phosphoric acid gel for 15 seconds; while in the second group (study group), it was pretreated using 5.25 sodium hypochlorite(NaOCl) for 60 seconds prior to acid etching. Each specimen was examined at 16 different sites, and evaluated for the etching pattern (types I, II, and III) distribution using SEM. A total of 320 microphotographs at 1,500 magnification were obtained using Auto-Cad 2007 software. Results: The etching pattern with phosphoric acid was not uniform with predominance of type III etching (65.63%), while the pretreated enamel surfaces showed a significant increase in type I and II(82.5%) etching patterns (P&lt;0.001). Conclusion: Treatment of primary teeth affected by hypocalcified AI using 5.25% NaOCl prior to phosphoric acid etching significantly improves the etching pattern which is required for good resin bonding.

Effects of Pulsed Nd:YAG Laser on Tensile Bond Strength and Caries Resistance of Human Enamel

2014 ◽  
Vol 39 (3) ◽  
pp. 273-282 ◽  
Author(s):  
X Wen ◽  
L Zhang ◽  
R Liu ◽  
M Deng ◽  
Y Wang ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Bond Strength ◽  
Nd:Yag Laser ◽  
Acid Resistance ◽  
Enamel Surface ◽  
Acid Etching ◽  
Laser Parameter ◽  
Pulsed Nd:Yag Laser ◽  
Resistance Evaluation ◽  
Human Enamel

SUMMARY This study aims to evaluate the effects of pulsed Nd:YAG laser on the tensile bond strength (TBS) of resin to human enamel and caries resistance of human enamel. A total of 201 human premolars were used in this in vitro study. A flat enamel surface greater than 4 × 4 mm in area was prepared on each specimen using a low-speed cutting machine under a water coolant. Twenty-one specimens were divided into seven groups for morphology observations with no treatment, 35% phosphoric acid etching (30 seconds), and laser irradiation (30 seconds) of pulsed Nd:YAG laser with five different laser-parameter combinations. Another 100 specimens were used for TBS testing. They were embedded in self-cured acrylic resin and randomly divided into 10 groups. After enamel surface pretreatments according to the group design, resin was applied. The TBS values were tested using a universal testing machine. The other 80 specimens were randomly divided into eight groups for acid resistance evaluation. Scanning electron microscope (SEM) results showed that the enamel surfaces treated with 1.5 W/20 Hz and 2.0 W/20 Hz showed more etching-like appearance than those with other laser-parameter combinations. The laser-parameter combinations of 1.5 W/15 Hz and 1.5 W/20 Hz were found to be efficient for the TBS test. The mean TBS value of 14.45 ± 1.67 MPa in the laser irradiated group was significantly higher than that in the untreated group (3.48 ± 0.35 MPa) but lower than that in the 35% phosphoric acid group (21.50 ± 3.02 MPa). The highest mean TBS value of 26.64 ± 5.22 MPa was identified in the combination group (laser irradiation and then acid etching). Acid resistance evaluation showed that the pulsed Nd:YAG laser was efficient in preventing enamel demineralization. The SEM results of the fractured enamel surfaces, resin/enamel interfaces, and demineralization depths were consistent with those of the TBS test and the acid resistance evaluation. Pulsed Nd:YAG laser as an enamel surface pretreatment method presents a potential clinical application, especially for the caries-susceptible population or individuals with recently bleached teeth.

Brushing Effect of Abrasive Dentifrices during At-home Bleaching with 10% Carbamide Peroxide on Enamel Surface Roughness

2006 ◽  
Vol 7 (1) ◽  
pp. 25-34 ◽  
Author(s):  
Luís Roberto Marcondes Martins ◽  
Claudia Cia Worschech ◽  
José Augusto Rodrigues ◽  
Gláucia Maria Bovi Ambrosano
Keyword(s):  
Surface Roughness ◽  
Artificial Saliva ◽  
Enamel Surface ◽  
Tooth Bleaching ◽  
Carbamide Peroxide ◽  
Peroxide Bleaching ◽  
Human Enamel ◽  
Over Time ◽  
At Home

Abstract During tooth bleaching abrasive dentifrices might change the outer superficial enamel. The aim of this in vitro study was to evaluate the roughness of human enamel exposed to a 10% carbamide peroxide bleaching agent at different times and submitted to different superficial cleaning treatments. The study consisted of 60 sound human enamel slabs, randomly assigned to different treatment groups: G1 - not brushed; G2 - brushed with a fluoride abrasive dentifrice; G3 - brushed with a non-fluoride abrasive dentifrice; and G4 - brushed without a dentifrice. There were 15 enamel slabs per group. Slabs of molar teeth were obtained and sequentially polished with sandpaper and abrasive pastes. A perfilometer was used to obtain the mean of Ra value on the surface of each specimen to initial and experimental times. Bleaching was performed on the enamel surface for six hours daily. After that, each slab received a cleaning surface treatment and was stored in artificial saliva. Analysis of variance (ANOVA) and Tukey's HSD hoc analysis (α =0.05) revealed significant differences in roughness values over time for enamel bleached and treated with different superficial cleaning methods. G1 and G4 showed no significant differences in roughness over time, G2 and G3 showed a significant increase in the surface roughness values. This in vitro investigation showed the sole use of 10% carbamide peroxide did not alter the enamel surface roughness, but the cleaning treatments that employed the use of brushing with abrasive dentifrices resulted in a significant increase of enamel surface roughness. Citation Worschech CC, Rodrigues JA, Martins LRM, Ambrosano GMB. Brushing Effect of Abrasive Dentifrices during At-home Bleaching with 10% Carbamide Peroxide on Enamel Surface Roughness. J Contemp Dent Pract 2006 February;(7)1:025-034.

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