Chemical Analysis of Enamel and Dentin Following the Application of Three Different At-home Bleaching Systems

2011 ◽  
Vol 36 (5) ◽  
pp. 529-536 ◽  
Author(s):  
FY Cakir ◽  
Y Korkmaz ◽  
E Firat ◽  
SS Oztas ◽  
S Gurgan

SUMMARY Purpose To determine the change in the chemical composition of enamel and dentin as well as to evaluate the differences in surface texture of the same dental hard tissues following three at-home bleaching systems in vitro. Methods Sixty extracted intact human anterior teeth were used in this study. Thirty teeth were used as samples for enamel, and the buccal surfaces of the remaining 30 teeth were abraded and used as dentin samples. Prior to bleaching treatments, calcium (Ca), phosphorus (P), potassium (K), sodium (Na), magnesium (Mg), fluoride (F), and oxygen (O) levels of each sample were measured using an energy dispersive spectrometer. The teeth were then randomly allocated into three groups according to the bleaching system used, as follows: GI, 10% carbamide peroxide (CP); GII, 20% CP; GIII, and 35% CP. Following the bleaching treatments, Ca, P, K, Na, Mg, F, and O measurements were repeated. The surface configurations were examined using scanning electron microscopy (SEM). The data were analyzed using Wilcoxon signed rank and Kruskal-Wallis tests followed by the Dunn test. Results All three bleaching systems tested caused similar changes in the chemical composition of enamel and dentin. Bleaching systems decreased Ca and K, while F and O levels increased in enamel. In dentin, Ca, P, and K levels decreased; however, Na, F, and O levels increased. SEM observations revealed no deleterious effect on enamel and dentin. Conclusion The use of home bleaching agents could affect the chemical composition of dental hard tissues, whereas the change in the chemical composition of enamel and dentin was not affected by the CP concentration of the bleaching systems used.

2007 ◽  
Vol 21 (2) ◽  
pp. 170-175 ◽  
Author(s):  
José Augusto Rodrigues ◽  
Glauco Paulo Felício Oliveira ◽  
Cristiane Mariote Amaral

Dental bleaching occurs due to an oxidation reaction between the bleaching agents and the macromolecules of pigments in the teeth. This reaction is unspecific and the peroxides can also affect the dental matrix causing mineral loss. On the other hand, recent studies have suggested that the thickener agent carbopol can also cause mineral loss. Thus, the objective of this study was to evaluate in vitro the effect of at-home dental bleaching on dental enamel microhardness after the use of bleaching agents with and without carbopol as a thickener agent. Bovine dental slabs with 3 x 3 x 3 mm were obtained, sequentially polished, and randomly divided into 4 groups according to the experimental treatment: G1: 2% carbopol; G2: 10% carbamide peroxide with carbopol; G3: carbowax; G4: 10% carbamide peroxide with poloxamer. Bleaching was performed daily for 4 weeks, immersed in artificial saliva. Enamel microhardness values were obtained before the treatment (T0) and 7 (T1), 14 (T2), 21 (T3), 28 (T4), and 42 (T5) days after the beginning of the treatment. ANOVA and Tukey's test revealed statistically significant differences only for the factor Time (F = 5.48; p < 0.01). All bleaching and thickener agents caused no alterations on the enamel microhardness.


2013 ◽  
Vol 38 (2) ◽  
pp. 142-150 ◽  
Author(s):  
LE Tam ◽  
P Bahrami ◽  
O Oguienko ◽  
H Limeback

SUMMARY Purpose Although damage to the structural integrity of the tooth is not usually considered a significant problem associated with tooth bleaching, there have been some reported negative effects of bleaching on dental hard tissues in vitro. More studies are needed to determine whether the observed in vitro effects have practical clinical implications regarding tooth structural durability. Objectives This in situ study evaluated the effect of 10% and 15% carbamide peroxide (CP) dental bleach, applied using conventional whitening trays by participants at home, on the fracture toughness of dentin. Methods Ninety-one adult volunteers were recruited (n ≈ 30/group). Compact fracture toughness specimens (approximately 4.5 × 4.6 × 1.7 mm) were prepared from the coronal dentin of recently extracted human molars and gamma-radiated. One specimen was fitted into a prepared slot, adjacent to a maxillary premolar, within a custom-made bleaching tray that was made for each adult participant. The participants were instructed to wear the tray containing the dentin specimen with placebo, 10% CP, or 15% CP treatment gel overnight for 14 nights and to store it in artificial saliva when not in use. Pre-bleach and post-bleach tooth color and tooth sensitivity were also evaluated using ranked shade tab values and visual analogue scales (VASs), respectively. Within 24–48 hours after the last bleach session, the dentin specimens were tested for fracture toughness using tensile loading at 10 mm/min. Analysis of variance, Kruskal-Wallis, χ2, Tukey's, and Mann-Whitney U tests were used for statistical analysis. The level of significance was set at p&lt;0.05 for all tests, except for the Mann-Whitney U tests, which used a Bonferroni correction for post hoc analyses of the nonparametric data (p&lt;0.017). Results The placebo, 10% CP, and 15% CP groups contained 30, 31, and 30 participants, respectively. Mean fracture toughness (+ standard deviation) for the placebo, 10% CP, and 15% CP groups were 2.3 ± 0.9, 2.2 ± 0.7, and 2.0 ± 0.5 MPa*m1/2 respectively. There were no significant differences in mean fracture toughness results among the groups (p=0.241). The tooth sensitivity VAS scores indicated a significantly greater incidence (p=0.000) and degree of tooth sensitivity (p=0.049 for VAS change and p=0.003 for max VAS) in the bleach groups than in the placebo group. The color change results showed generally greater color change in the bleach groups than in the placebo group (p=0.008 for shade guide determination and p=0.000 for colorimeter determination). Conclusions There were no significant differences in in situ dentin fracture toughness results among the groups. The results of this study provide some reassurance that dentin is not overtly weakened by the bleaching protocol used in this study. However, the lack of a statistically significant difference cannot be used to state that there is no effect of bleach on dentin fracture toughness.


Author(s):  
Nandita Bansal

Introduction: Intracoronal bleaching is the simplest, least invasive, and least expensive means available to lighten non-vital discolored teeth. The objective of the study: To evaluate the intra coronal bleaching efficacy of 35% Carbamide peroxide relative to 35% Hydrogen peroxide and Sodium perborate using artificially stained extracted human teeth. Materials and Methods: Eighty extracted human permanent maxillary and mandibular anterior teeth and single-rooted premolars were artificially stained using whole human blood and root canal treatment was completed. They were bleached twice 7 days apart using: Group I (n=20) – 35% Carbamide peroxide gel, Group II (n=20) – 35% Hydrogen peroxide gel, Group III (n=20) – 2 gm Sodium perborate mixed with per ml of distilled water, Group IV (n=20)– Distilled water only (control). Evaluation of shade was performed on day 0,7,14. Results: On day 7, In Groups I and Group II, there was a reduction in the shade by 2 vita tab positions, whereas Group IIIlightened by 1-tab position only. On day 14, CP and HP lightened by overall 3-tab positions and SP by 2-tab positions. There were no statistical differences between the groups on day 7 and day 14. Conclusion: 35% Carbamide peroxide, 35% Hydrogen peroxide and Sodiumperborate were equally effective for Intra coronal bleaching.


2006 ◽  
Vol 7 (1) ◽  
pp. 25-34 ◽  
Author(s):  
Luís Roberto Marcondes Martins ◽  
Claudia Cia Worschech ◽  
José Augusto Rodrigues ◽  
Gláucia Maria Bovi Ambrosano

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.


2017 ◽  
Vol 42 (4) ◽  
pp. 347-356 ◽  
Author(s):  
J Perdigão ◽  
VQ Lam ◽  
BG Burseth ◽  
C Real

SUMMARY This clinical report illustrates a conservative technique to mask enamel discolorations in maxillary anterior teeth caused by hypomineralization associated with enamel fluorosis and subsequent direct resin composite to improve the anterior esthetics. The treatment consisted of at-home whitening with 10% carbamide peroxide gel with potassium nitrate and sodium fluoride in a custom-fitted tray to mask the brown-stained areas, followed by resin infiltration to mask the white spot areas. An existing resin composite restoration in the maxillary right central incisor was subsequently replaced after completion of the whitening and resin infiltration procedures, whereas the two misaligned and rotated maxillary lateral incisors were built up with direct resin composite restorations to provide the illusion of adequate arch alignment, as the patient was unable to use orthodontic therapy.


2015 ◽  
Vol 18 (4) ◽  
pp. 104
Author(s):  
Javier Higuera ◽  
Ariel Denis Espinoza ◽  
Sebastian Contreras Marino

<p align="left"><span style="color: #212121;"><span><span>Despite the extensive literature available on laser at the present, there are few articles about the temperature of laser radiation and its propagation on dental hard tissues. The present study general objective is to evaluate </span></span></span><span style="color: #212121;"><span><span><em>in vitro</em></span></span></span><span style="color: #212121;"><span><span><span> the effect of temperature increase produced by the laser radiation of 940 nm on the dental hard tissues and, as specific objectives a) analyze current parameters using 940 nm laser on dental hard tissues b) assess the most appropriate criteria for this wavelength on dental hard tissues. 4 groups of 5 teeth each (lower incisors, upper incisors, canines and molars) were irradiated with 6 powers and frequencies (0.1 to 0.4W, in continuous or pulsed mode). The results of this study allow us to ensure that, in the chosen parameters, major powers, but delivered in pulsed manner, generate less temperature rise. Extremely significant differences were found between groups of lower incisors and molars. 0.1W power, pulsed mode for 20 msec, with 20 millisecond intervals, generated less than 4 Celsius degrees of temperature increase in all the cases studied. In conclusion, the use of powers of up to 0.4W, in pulsed mode, generated thermal effects of less than 4 Celsius degrees.</span></span></span></span></p>


1996 ◽  
Author(s):  
David C. Attrill ◽  
Simon R. Farrar ◽  
A. S. Blinkhorn ◽  
R. M. Davies ◽  
Mark R. Dickinson ◽  
...  

Author(s):  
D.A. Kuzmina ◽  
E.Yu. Mendosa ◽  
E.E. Maiorov ◽  
N.S. Narusak ◽  
A.I. Sakerina ◽  
...  

The article data on the study of reflection spectra of hard tooth tissues and dental restoration materials are presented. The method of investigation of dental hard tissues and dental restoration materials — the method of diffuse reflection electron spectroscopy is defined. The relevance of the work, since a high level of restoration aesthetics in therapeutic dentistry is important is shown. Reflection spectra of the studied samples on an automated spectrofluorometer “SDL-2” were performed. Spectral dependences of the reflection coefficient of enamel and dentin sections, as well as intact teeth of patients of different ages, were obtained. The spectral dependences of the reflection coefficient of various dental restoration materials were analyzed.


2018 ◽  
Vol 69 (6) ◽  
pp. 1574-1577
Author(s):  
Monica Monea ◽  
Daniela Esian ◽  
Reka Soos ◽  
Adrian Tohati ◽  
Alexandru Sitaru ◽  
...  

Lasers can interact with dental tissues inducing changes in tooth characteristics, regarding the surface morphology and elemental composition. The alterations were observed in Calcium, Phosphorus, Sodium, Oxygen and Carbon elements, which influence the resistance and chemical properties of dental hard tissues. The thermal energy used by laser reduces water content of the tissues and as a consequence, the level of oxygen composition decreases after irradiation. Numerous studies had demonstrated its ability to ablate hard-tissues, without any detrimental thermal effects such as cracking or melting for the adjacent tissues. The aim of this article is to present the in vitro effects of Er:YAG laser in comparison with sonic, ultrasonic and manual instruments on the root cement during scaling and root planning, evaluated by scanning electron microscope. The study was conducted on extracted teeth, divided in four groups according to the method used for scaling and root planning. The specimens were analyzed by scanning electron microscopy and the morphological alterations of the cement were evaluated based on a scoring system. Data were statistically analyzed using Mann-Whitney test and the level of significance was set at p[0.05.We noted unfavorable results on the root cement after using Er:YAG laser as craters and cracks induced by heat. There was a greater amount of roughness on the root surface after Er:YAG was used for scaling and root planning compared to manual, sonic and ultrasonic methods. Despite favorable results obtained after the use of Er:YAG laser during periodontal treatment, further clinical studies are necessary in order to determine in which moment of the therapy these methods are most suitable.


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