Analysis of Photoreflectance and Microhardness of the Enamel in Primary Teeth Submitted to Different Bleaching Agents

2007 ◽  
Vol 32 (1) ◽  
pp. 9-12 ◽  
Author(s):  
Sabrina Fróes Faria Campos ◽  
Ilene Cristine Rosia César ◽  
Egberto Munin ◽  
Priscila Christiane Suzy Liporoni ◽  
Marcos Augusto do Rego

Treatment of darkened teeth in children is of great importance from an esthetic-functional point of view and for the psychoemotional development of the child. The objective of the present study was to determine the in vitro efficacy of three bleaching agents for whitening of artificially stained primary teeth. Fifty anterior primary teeth were artificially stained and then divided into three experimental groups (n = 15) submitted to bleaching treatment with 35% hydrogen peroxide gel, 35% carbamide peroxide gel, and 35% carbamide peroxide gel mixed with sodium perborate powder. The control group (n = 5) was not submitted to any bleaching treatment. Color changes were evaluated with a reflectance spectrophotometer and possible alterations in the enamel surface after bleaching were measured by Vickers microhardness testing. The data were assessed using the Student's t test. The results confirmed the bleaching action of the three agents tested. No significant difference in mean microhardness was observed between the three bleaching agents when compared to the control group.

2013 ◽  
Vol 4 (4) ◽  
pp. 235-240
Author(s):  
Carlos Rocha Gomes Torres ◽  
Maria Filomena Rocha Lima Huhtala ◽  
Ana Paula Martins Gomes ◽  
Carolina Judica Ramos ◽  
Karen Cristina Kazue Yui ◽  
...  

ABSTRACT Discoloration of nonvital teeth is an esthetic deficiency frequently requiring bleaching treatment. The purpose of this study was to evaluate in vitro the effect of bleaching agents on two different cervical barriers in order to minimize or prevent the leakage along the root canal filling in the intracoronal bleaching procedures. Ninety-six extracted human molars were used which were biomechanically prepared, filled and divided into eight groups. The cervical barriers tested were zinc phosphate cement (ZPC) and resin-modified glass ionomer cement (RMGIC) applied (3 mm of thickness) at the cementoenamel junction level. Forty-eight specimens were divided into four groups for each cervical barrier: (1) control group without bleaching agent, (2) a mixture of sodium perborate and distilled water, (3) a mixture of sodium perborate and 10% carbamide peroxide and (4) a mixture of sodium perborate and 35% carbamide peroxide. The bleaching agents were placed inside the pulp chamber for 7 and 14 days, and the access opening was sealed with Cimpat. After 21 days, microleakage evaluation of 2% rhodamine B dye solution at dentin-cervical barrier interface was performed by a stereomicroscope. Data were submitted to Kruskal-Wallis, Dunn's and Dunnett's tests, with a significance level of 0.05. The results demonstrated no statistically significant differences among the control group and the experimental groups for each cervical barrier (ZPC and RMGIC); there were no significant differences among the bleaching agents for the same barrier and RMGIC barrier provided better sealing than ZPC (p < 0.05). Therefore, the bleaching agents demonstrated similar performance when tested for the same cervical barrier and RMGIC barrier provided better sealing than the ZPC barrier, regardless of the association of bleaching agents used. How to cite this article Yui KCK, Huhtala MFRL, da Silva EG, Ramos CJ, Torres CRG, de Paiva Gongalves SE, Gomes APM. Effect of Bleaching Agents on the Sealing of Cervical Barrier in Intracoronal Bleaching Procedures. World J Dent 2013;4(4): 235-240.


2017 ◽  
Vol 5 (2) ◽  
pp. 129-135
Author(s):  
Nia Nurhaeni ◽  
Denas Symond ◽  
Bambang Ristiono

One of the aesthetic problem which had bother and become a complaint was teeth discoloration that can be overcome by dental bleaching procedures. The use of tooth whitening ingredient can cause side effects such as tooth sensitivity and mucous irritation. Therefore, many researchers have been looking for a safer alternatives materials  to be used as tooth whitening ingredients including Strawberry (Fragaria x ananassa) contain of elegat acid and malic acid and Lime (Citrus aurantifolia) contain of citric acid which have potential to whiten the teeth. The purpose of this research is to determine differences strawberry and lime fruit as a natural ingredient of tooth whitening. This research used in vitro laboratory experiment method by using 30 post-extraction premolar on teeth divided into three groups, namely the treatment of strawberry concentration of 100% (K1), the treatment group lime concentration of  2.5% (K2 ) and the treatment control group carbamide peroxide 10% (K3). Color changes measurements was observed pretest and posttest by 15 observers using Shade Guide VITAPAN classical. The research showed that strawberry concentration of 100% have an average difference in the color of teeth is 6.40, lime concentration of 2.5 at 6.20 and carbamide peroxide 10% as the control group amounted to 3.20. Based on the Kruskal Wallis test there are differences in the average value of the observation color of the teeth was significant (P <0.05) and continued with different test further the Post Hoc Test Mann Whitney gained significant difference (p> 0.05) between treatment groups strawberry 100% with carbamide peroxide 10%, lime and 2.5% carbamide peroxide 10%, while among the treatment groups strawberries 100% with 2.5% lime fruit is not significantly different because it has a value of p> 0.05. Strawberry concentration of 100% more effective to whiten teeth than lime concentration of 2.5%, but there is no significant difference in teeth whitening, while lime is more effective than carbamide peroxide 10%. Keywords:Strawberry, lime, carbamide peroxide 10%, tooth whitening.


2015 ◽  
Vol 26 (4) ◽  
pp. 373-377 ◽  
Author(s):  
Muhammet Karadas ◽  
Zeynep Yesil Duymus

<p>This <italic>in vitro</italic> study evaluated the whitening effect of four different over-the-counter products compared with a 10% carbamide peroxide (CP) bleaching gel. Specimens obtained from bovine incisors were stained in a tea solution and randomly divided into six groups according to the product used (n=10): CT: conventional toothpaste (negative control); CWT: Crest 3D White toothpaste; CWR: Crest 3D White mouth rinse; CWS: Crest 3D White strips; DW: Dazzling White (paint-on gel); and OP: Opalescence PF 10% CP (at-home bleaching gel, positive control). Over-the-counter products and 10% CP were used according to the manufacturer's recommendations. Color measurements were performed according to the CIELab system using spectrophotometer after staining, and after 4 and 8 weeks of the treatment procedure. The ∆E, ∆L, ∆a, and ∆b values were calculated. The data obtained were analyzed by repeated-measures ANOVA. Tukey's test for multiple comparisons was applied (p<0.05). All groups, except CWT, were effective in tooth whitening in comparison with conventional toothpaste. There was no significant difference in tooth whitening between CWT and CT (p=0.93). CWS, DW and OP groups presented significantly higher color changes than the CWR group. DW and CWS showed similar tooth whitening to OP.</p>


2014 ◽  
Vol 15 (4) ◽  
pp. 407-412 ◽  
Author(s):  
Carlos Rocha Gomes Torres ◽  
Graziela Ribeiro Batista ◽  
Alessandra Bühler Borges ◽  
Paula Tamião Arantes ◽  
Annette Wiegand ◽  
...  

ABSTRACT Aim The aim of this study was to investigate the influence of simulated pulpal pressure on efficacy of bleaching gels. Materials and methods Cylindrical enamel-dentin specimens from bovine teeth (3 mm diameter, enamel and dentin layer each 1 mm thick) were divided into 4 groups, according to the bleaching treatment: negative control (non-bleached), bleached with 10% carbamide peroxide (CP), bleached with 7.5% hydrogen peroxide (HP) and bleached with 35% hydrogen peroxide. Ten percent CP gel was applied for 8 h/day and 7.5% HP for 1 h/day, during 14 days. For 35% HP treatment, two sessions of 45 minutes each were employed. In intermediate periods specimens were stored in artificial saliva. Experimental groups (n = 19) were subdivided according to the simulation of pulpal pressure (25 mm Hg) during bleaching treatment. Initial color measurement and after bleaching treatment were assessed by spectrophotometry, using CIE L*a*b* system. The data were statistically analyzed by ANOVA and Dunnett's posthoc tests (p < 0.05). Results There was significant difference of ∆E for all experimental groups compared to negative control group, according to Dunnett's test (p < 0.0001). There were no significant difference for total color variation (∆E) among experimental groups (p > 0.05). Conclusion It was concluded that all bleaching gels showed bleaching efficacy compared to non-bleached group and that the simulated pulpal pressure did not influence the bleaching outcomes of the tested gels. Clinical significance Although numerous in vitro studies investigating the efficacy of bleaching agents have been performed, they do not properly simulate the pulpal pressure. In order to make these studies closer to clinical conditions, it is important to reproduce these conditions in laboratory, so the results can be more reliable. This in vitro study was performed under simulated pulpal pressure, aiming to investigate its influence on dental bleaching outcomes. How to cite this article Borges AB, Batista GR, Arantes PT, Wiegand A, Attin T, Torres CRG. Influence of Simulated Pulpal Pressure on Efficacy of Bleaching Gels. J Contemp Dent Pract 2014;15(4):407-412.


2007 ◽  
Vol 19 (1) ◽  
pp. 185
Author(s):  
Y. Takagi ◽  
M. Shimizu ◽  
M. Morimura ◽  
S. Yokomizo ◽  
K. Hara ◽  
...  

Embryos of various species are successfully vitrified and cryopreserved in liquid nitrogen (&lt;−150°C). Like the preservation of frozen somatic cells cooled by dry ice (−79°C), the cryopreservation of embryos at −79°C is useful for a reduction in the shipping costs. The purpose of this study was to evaluate the effect of the cryopreservation period at −79°C on the in vitro embryo viability of vitrified mouse morulae after thawing. Morula-stage mouse embryos were collected from superovulated ICR donors 70 h after hCG injection. The embryos were exposed first to 5% DMSO + 5% ethylene glycol (EG) in Dulbecco's PBS + 20% FCS (mPBS) for 2 min, and then equilibrated for 20–30 s in a vitrification solution composed of 10% DMSO + 10% EG + 0.6 M sucrose in mPBS. The embryos were loaded onto cryoloops (Lane et al. 1999 Nat. Biotech. 17, 1234–1236) and plunged directly into liquid nitrogen. The cryoloops were placed in 1.2-mL cryotubes and stored in a −79°C freezer for 1–7 days. The embryos were warmed by passing through 4 dilution media and rinsed with mWM culture medium. They were then cultured at 37°C in 5% CO2 for 44 h. Non-cryopreserved embryos and embryos cryopreserved in liquid nitrogen served as controls. Data were analyzed by the chi-square test and the Student's t-test. Results are shown in Table 1. There was no significant difference (P &gt; 0.01) in the developmental abilities to the blastocyst stage of the vitrified embryos that were cryopreserved at −79°C for 1 day, 3 days, and 5 days, the embryos cryopreserved in liquid nitrogen, and the non-vitrified control. The blastocyst rate of embryos was significantly lower (P &lt; 0.01) for the Day 7 group than for the control group. The cell numbers of blastocysts were significantly lower (P &lt; 0.01) for the Day 1, Day 3, Day 5, and Day 7 groups than for the control group. This study suggests that vitrified mouse morulae can be successfully cryopreserved at −79°C for 5 days. Table 1. Effect of the cryopreservation period on the viability of vitrified mouse morulae preserved at −79°C


2014 ◽  
Vol 62 (3) ◽  
pp. 235-242
Author(s):  
Grazielle Morais de SOUZA ◽  
Luis Cardoso RASQUIN ◽  
Fabíola Bastos de CARVALHO

OBJECTIVE: To evaluate in vitro the sealing ability of three materials used as cervical barrier for internal dental bleaching. METHODS: Thirty-three canines were selected, and after biomechanical root canal preparation, the canals were filled by lateral condensation technique. After the filling material setting reaction, the teeth were randomly divided into three groups of ten teeth each, according to the following materials for constructing the cervical barrier: X Temp LC; Vitro Fil; Coltosol. The control group consisted of three teeth, without placement of the cervical cap. Sodium perborate /distilled water associated with 2% Rhodamin B were used as bleaching substance. After placing the bleaching agent in the pulp chamber, access cavities were sealed with temporary cement IRM and samples were stored at 37 ° for 7 days. After this period, the samples were cleaved longitudinally, and leakage was evaluated by the visual method. The data were submitted to Pearson test with a 5% level of significance. RESULTS: No statistically significant difference was found between the study groups, however, the largest number of specimens with a lower degree of leakage were found in the Coltosol group. CONCLUSION: All the materials evaluated for making the cervical cap allowed some level of leakage.


2014 ◽  
Vol 43 (3) ◽  
pp. 209-213
Author(s):  
Nadia de Souza FERREIRA ◽  
Patrícia Campos Ferreira da ROSA ◽  
Raffaela Di Iorio Jeronymo FERREIRA ◽  
Marcia Carneiro VALERA

Introduction: There is great demand for esthetic treatment by patients who have discolored teeth, because currently aesthetic standards have become stricter and many patients have tooth bleaching procedures performed before or during orthodontic treatment. Objective: To evaluate the bonding of orthodontic brackets to human molars after internal tooth bleaching. Material and method: Forty molars were divided into four groups according to the bleaching agent used: PS) sodium perborate + water; PC) carbamide peroxide; PC + PS) carbamide peroxide + sodium perborate; Cont) water (control group). Bleaching agents placed inside the pulp chambers were replaced every 7 days for 2 weeks, and the brackets were bonded 30 days after the end of bleaching. The shear strength test was performed in a universal testing machine (Emic). Result: ANOVA with a significance level of 5% (p > 0.05), showed no statistically significant difference between groups (p = 0.1214). Conclusion: It was concluded that the different bleaching agents studied did not interfere with the bond strength of brackets to enamel and bonding the brackets 30 days after internal bleaching is a safe procedure.


2017 ◽  
Vol 16 ◽  
pp. 1-9 ◽  
Author(s):  
Fernando Pelegrim Fernandes ◽  
Cecília Pedroso Turssi ◽  
Fabiana Mantovani Gomes França ◽  
Roberta Tarkany Basting ◽  
Flávia Lucisano Botelho do Amaral

Aim: To assess the effect of a mouthwash containing hydrogen peroxide (HP) on Knoop microhardness (KMH) of bovine enamel. Methods: Fifty-one enamel slabs were polished and divided into groups (n=17), according to the product used during 28 days: HP – mouthwash containing 1,5% of HP (4 min, once/day); CP - 10% carbamide peroxide gel (2 hours/day); AS - no treatment (kept in artificial saliva (AS). Each fragment was submitted to KMH test (three indentations/fragment, with a 50 g load for 5 sec) four times: before (baseline); during (14 and 28 days) and after (7 days immerged in AS) the bleaching treatment. The data were submitted to repeated-measures two-way ANOVA (α=0.05). Results: There was no effect of the interaction between the time and treatment factors (p=0.327). No significant effect was observed from the time factor (p = 0.054). The factor treatment showed significant effect (p =0.002). Regardless of time, the KMH of the enamel submitted to HP was lower than the value observed with the use of CP, which did not differ significantly from the control group (AS). Conclusion: Although there was a trend of decreasing enamel microhardness over time, only the mouthwash containing hydrogen peroxide had a significant effect.


2013 ◽  
Vol 1 (4) ◽  
pp. 316
Author(s):  
Karin Faust Souza ◽  
Carla Miranda ◽  
Izabel Cristina Santos Almeida

The purpose of this study was to evaluate in vitro the effect of APF, gel and foam, for 1 to 4 minutes, on artificial enamel caries-like lesion of primary teeth submitted to the pH cycling. The specimens with medium values of initial superficial enamel micro-hardness between 272 and 331KHN were selected for the formation of the artificial caries lesion. Later, they were randomly divided into 6 groups (n=15): no pH cycling control, cycled control, gel 1min, gel 4min, foam 1min and foam 4min.The no pH cycling control group was maintained in an humid environment, while the application of APF and the pH cycling were accomplished. After, the specimens were sectioned at the center for the enamel cross-sectional micro-hardness test. The values of micro-hardness of the depths from 20 to 180mm were converted into percentile of mineral volume (%Vol) and the area of mineral recovery (∆ZR) was calculated.  In spite of there is no statistically significant differences, it was observed through the analysis of the ∆ZR a difference in the values for the groups gel 1min and foam 4min (p>0.05). The evaluation of %Vol indicated a significant difference only at 60mm depth (p=0.005). This study concluded that a single application of APF gel or foam, for 1 or 4 minutes, do not remineralize artificial enamel caries-like lesion of primary teeth


Author(s):  
Rathika Rai ◽  
M. A. Easwaran ◽  
K. T. Dhivya

Aim: To evaluate the surface detail reproduction of dental stone this is immersed in different disinfectant solution and studied under stereomicroscope. Methodology: Total number of 30 specimens of dental stone (Type III) were made with measurements of 1.5cm diameter and 1cm height .This samples are divided in to 3 groups group A,B,C. were A is immersed in Distilled water which was taken as control group ;B is immersed in 2% Glutaraldehyde and C is immersed in 5%sodium hypochlorite. Each specimen were immersed in the disinfectant solution for 15 minutes and dried under room temperature for 24 hrs. After 24 hrs each specimens are studied under stereomicroscope for surface details. Result: The results showed no significant difference in the surface irregularities and porosities for a group 1 and group 2 except group 3 which showed significant increase in the porosities, surface irregularities and erosions after disinfection with 5% NaHOCl by immersion method. Conclusion: The surface detail reproduction capacity of die stone was adversely affected when 5% Sodium hypochlorite was used as disinfectant solution when compare d to control group and 2% Glutaraldehyde


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