Effects of bleaching using 10% carbamide peroxide with calcium or amorphous calcium phosphate on enamel mineral content and hardness (original) (raw)
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Journal of Esthetic and Restorative Dentistry, 2011
Statement of the Problem: The effects of amorphous calcium phosphate (ACP)-containing bleaching agents on enamel surface have not been clarified yet. Purpose: The study aims to evaluate the effects of different bleaching agents, either associated with ACP, or not, on enamel Knoop microhardness (KHN) and surface roughness (SR). Materials and Methods: The home-use hydrogen peroxide (HP) bleaching agents PolaDay 7.5% (HP7.5; SDI Limited, Bayswater, Victoria, Australia), PolaDay 9.5% (HP9.5; SDI Limited); DayWhite ACP-7.5% (ACP7.5; Discus Dental, Culver City, CA, USA) and DayWhite ACP 9.5% (ACP9.5; Discus Dental), and the in-office agents PolaOffice 35% (HP35; SDI Limited) and Opalescence XtraBoost 38% (HP38; Ultradent Products, South Jordan, UT, USA) were applied to polished enamel slabs (N = 10) for 30 minutes/day for 21 consecutive days (home-use) or in one session a week, for 3 weeks (in-office). KHN and SR were tested before (baseline), during (7, 14, 21 days), and after (7 and 14 days in artificial saliva) the bleaching treatment. Results: KHN evaluation revealed no significant difference among bleaching agents (p > 0.05); however, there was a significant decrease during bleaching treatment (p < 0.0001). KHN values attained in the post-treatment phase were statistically similar to baseline values (p > 0.05). SR was not altered during and after treatment, with the exception of PH38, which showed an increase in SR during bleaching treatment and a recovery after treatment. The ACP7.5 showed a trend to decreasing SR values during the bleaching treatment, but this decrease was only significant when associated with 14 days of immersion in artificial saliva, when the enamel was less rough than at baseline. Conclusions: Bleaching agents caused a decrease in enamel KHN, but values were recovered after treatment, showing the importance of saliva in recovering mineral content. SR was altered during or after treatment, depending on HP concentration/association with ACP. The beneficial effects of adding ACP to bleaching formulas on SR may be restricted to lower HP concentrations in association with the remineralizing effect of saliva.
International Journal of Advanced Research (IJAR), 2018
Bleaching agents have effect on chemical and morphological structure of enamel that must be taken into account when this therapy is used. Aim: reveal and compare the effect of two bleaching agents containing a high a concentration of hydrogen peroxide (HP) and carbamide peroxide (CP) on enamel surface and evaluate the re-mineralizing effect of amorphous calcium phosphate gel (ACP) on enamel surface. Material and method: 32 extracted human upper first premolars were divided into 4 Control groups (CG) (before bleaching procedure), was named as: CG I, CG II, CG III and CG IV. 4 Experimental groups (EG) in which the teeth of the control groups utilized as experimental after bleaching procedure. Teeth were subjected to 40% HP in EGI, 35% CP bleaching in EGII, 40% HP & ACP in EGIII and 35 % CP & ACP in EGIV. All groups were prepared to SEM analysis and EDAX. Results: Both HP and CP significantly altered enamel superficial surface structure causing irregular surface, erosive lesions and craters. Globular precipitates covering the entire enamel surface and occlusion of enamel rod ends were detected following ACP application.The chemical profile results revealed decrease in Ca and P contents of enamel surface following bleaching, while they increased after application of ACP and the opposite was to the carbon content. Conclusion: Hydrogen peroxide and carbamide peroxide have an erosive effect on enamel surface while ACP has a re-mineralizing effect.
Operative Dentistry, 2011
SUMMARY This study was designed to evaluate in vitro the efficacy of a novel at-home bleaching technique using 10% or 16% carbamide peroxide modified by casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and its influence on the microhardness of bleached enamel. A total of 40 bovine incisors were divided into four groups (n=10) according to the bleaching agent used: 10% carbamide peroxide only; a blend of 10% carbamide peroxide and a CPP-ACP paste; 16% carbamide peroxide only; and a blend of 16% carbamide peroxide and a CPP-ACP paste. During the 14-day bleaching regimen, the samples were stored in artificial saliva. The Vickers microhardness and color of the teeth were assessed at baseline (T0) and immediately after the bleaching regimen (T14) using a microhardness tester and a spectrophotometer, respectively. The degree of color change was determined by the Commission Internationale de l'Eclariage (CIE) L*a*b* system (ΔE, ΔL*, Δa*, and Δb*) and Vita shade guide paramet...
Dental bleaching agents with calcium and their effects on enamel microhardness and morphology
Brazilian Journal of Oral Sciences, 2015
Aim: To evaluate enamel microhardness and morphology after bleaching with hydrogen peroxide containing calcium in different concentrations. Methods: One hundred specimens of human teeth were ground and polished and had the initial microhardness evaluated. The specimens were randomly assigned into five groups (n=20): Group 1-Control group (no treatment); Group 2-Home Peroxide 6% (without calcium); Group 3-Home Peroxide 7.5% (without calcium); Group 4-White Class 6% (with calcium); Group 5-White Class 7.5% (with calcium). For each group, the bleaching was performed according to the manufacturer's specifications. The specimens were bleached once a day for 5 days and subjected to pH cycling. Microhardness and scanning electron microscopy (SEM) analysis were performed before and after bleaching. Results: The results showed that groups submitted to bleaching treatment presented hardness loss compared to the control group. The group of 7.5% hydrogen peroxide with calcium showed a lower percentage of hardness loss in relation to other groups. Conclusion: Calcium in association with a higher hydrogen peroxide concentration may decrease microhardness changes on enamel.
Journal of Applied Oral Science, 2009
The purpose of this study was to assess the effect of home-use bleaching agents containing 10% carbamide peroxide and 7.5% hydrogen peroxide on enamel microhardness and surface micromorphology. Material and Methods: Enamel slabs (n=10) received the bleaching agents for 1 h/day and remained in artificial saliva solution for 23 h/day, during a total period of 21 days. Control group was composed of enamel slabs that were not subjected to treatment with the agents and were maintained in artificial saliva solution. Microhardness tests were performed before treatment application, 21 days of treatment and 14 days after the end of treatment. Scanning electron microscopy analyses were performed after 14 days after the end of bleaching treatment by 3 calibrated observers who attributed scores. Results: The Tukey's test (α=0.05) showed no significant differences in microhardness values among bleaching agents, at 21 days of treatment and a significant increase in microhardness for different agents after 14 days from the end of treatment. Fisher's exact test showed differences in micromorphology of enamel between control and experimental groups (p=0.0342). Conclusions: Bleaching agents containing 10% carbamide peroxide and 7.5% hydrogen peroxide may change surface micromorphology of enamel, although no changes in microhardness were observed.
Effect of Bleaching Agents on the Hardness and Morphology of Enamel
Journal of Esthetic and Restorative Dentistry, 2002
Pwpose: The goal of the present laboratory study was to analyze the effect of two home bleaching agents (Opalescence l o % , Ultradent, and Hi-Lite 11, Shofu) as well as the separate solutions of 1 0 % carbamide peroxide primary components (3 % hydrogen peroxide and 7 % urea) on enamel microhardness and surface morphology. Materials and Methods: Thirty human molars stored in water for no longer than 3 months were selected. Their facial and lingual surfaces were embedded in acrylic resin, and the specimens were polished with up to 600-grit sandpaper. The 30 molar sections were divided into five groups as per treatment modality (n = 6); group 1, 10% carbamide peroxide bleach with carbopol (Opalescence, Ultradent); group 2, oxygen-free gel bleach (Hydroxylite, Hi-Lite 11, Shofu); group 3 , 3 % hydrogen peroxide with carbopol (Dermus Pharmacy, Florian6polis, SC, Brazil); group 4, 7 % urea treatment (Dermus Pharmacy); and control, group 5, artificial saliva (Dermus Pharmacy). Prior to treatment, six indentations (Vickers) were made on each of the six surfaces in each group under a load of 100 g for 30 seconds. Bleaching procedure was conducted for 3 hours per day for 2 weeks, the control group excepted. Following each bleaching session, the specimens were washed with deionized water and kept in artificial saliva at 37"C, this solution being changed daily. Pre-and post-treatment microhardness data were analyzed using a two-way analysis of variance. In a similar way, 30 other specimens underwent the same procedures. After the bleaching period, the samples were observed under the scanning electron microscope. Results: Specimens submitted to bleaching treatment with 3 % hydrogen peroxide gel as described in this study showed a significant reduction of surface microhardness (p < .0001). The other treatment modalities had no effect on surface microhardness. No morphologic alterations were observed on enamel submitted to bleaching gel of 10% carbamide peroxide (Opalescence), oxygen-free gel (Hi-Lite 11, Shofu), or 7 % urea solution compared with the control (artificial saliva). However, the specimens bleached for 3 hours per day for 2 weeks with 3% hydrogen peroxide gel presented areas of mild erosion. The effect, nevertheless, was not uniform, occurring with varying intensity on all samples of enamel bleached with 3% hydrogen peroxide.
In Vitro Comparative Study of Two Different Bleaching Agents on Micro-hardness Dental Enamel
Journal of the College of Physicians and Surgeons--Pakistan : JCPSP, 2016
OBJECTIVE To evaluate the effect of home-use bleaching agent containing 16% Carbamide Peroxide (CP) and in-office bleaching agent containing 38% Hydrogen Peroxide (HP) on enamel micro-hardness. STUDY DESIGN An in vitroexperimental study. PLACE AND DURATION OF STUDY Department of Operative Dentistry and Science of Dental Materials at Dr. Ishrat-ul-Ebad Khan Institute of Oral Health Sciences, Dow University of Health Sciences and Material Engineering Department of NED University of Engineering and Technology, Karachi, from July to December 2014. METHODOLOGY Atotal of 90 enamel slabs from 45 sound human 3rd molar were randomly divided into 3 groups. Each group contained 30 specimens (n=30). Group 1 was kept in artificial saliva at 37°C in incubator during the whole experiment. However, Groups 2 and 3 were treated with power whitening gel and tooth whitening pen respectively. After bleaching session, specimens were thoroughly rinsed with deionized water again for 10 seconds and then sto...
Objectives: This single-blind in-vitro study was conducted to assess the effect of different in-office and home bleaching agents on the micro-hardness and color changes of dental enamel. Materials and Methods:Twenty human premolar teeth extracted for orthodontic reasons were used in the study. After mounting, an area of 2 mm circumference was chosen in the mid buccal section of all premolars for bleaching-agent application. The specimens were divided into four (4) groups. Each group was exposed to a specific bleaching material according to its manufacturer's instructions. (GI) Control group; no treatment, teeth were immersed in artificial saliva, (GII) Fläsh, (32% hydrogen peroxide), (GIII) Opalescence Xtra Boost (40% hydrogen peroxide) and (GIV) Opalescence Home (35% carbamide peroxide). Micro-hardness and color changes were recorded for each specimen before and 24-hrs after the application of bleaching materials using Vickers Microhardness Test Machine and a Knoop diamond with 50g load applied for 10s and ColoreyeSpectro-Photometer, respectively. The value deltaE(ab)*=3.3 was used as an acceptable value in subjective visual evaluations. Statistical analysis of data was done using One-Way ANOVA and Tukey'srange test, with significance level set at 5%. Results: Micro-hardness testing showed that while there was an increase in micro-hardness after use of Opalescence Home (GIV), there was a general tendency towards decreased micro-hardness with the other bleaching groups (GII) and (GIII). However, due to small sample size the difference was not statistically significant. Substantial color differences were noticed in readings of deltaE for groups subjected to bleaching. Conclusion: It can be concluded that using different bleaching agents can affect enamel micro-hardness and color. However, this was only a pilot study and more detailed results will be outlined once complete number of specimens is examined. Further studies with different materials are necessary to conclude a significant relation.
Peroxide bleaching agent effects on enamel surface microhardness, roughness and morphology
Brazilian Oral Research, 2004
The aim of this study was to evaluate the surface roughness, microhardness and morphology of human enamel exposed to six bleaching agents (at baseline and post-treatment). Human dental enamel samples were obtained from human third molars and randomly divided into seven groups (n = 11): control, Whiteness Perfect - 10% carbamide peroxide (10% CP), Colgate Platinum - 10% CP, Day White 2Z - 7.5% hydrogen peroxide (7.5% HP), Whiteness Super - 37% CP, Opalescence Quick - 35% CP and Whiteness HP - 35% HP. Bleaching agents were applied according to manufacturers' instructions. The control group remained not treated and stored in artificial saliva. Microhardness testing was performed with a Knoop indentor and surface roughness was analyzed with a profilometer. Morphologic observations were carried out with scanning electron microscopy (SEM). Results were statistically analyzed by two-way analysis of variance and Tukey's test (5%), and revealed a significant decrease in microhardness...
Brazilian Dental Journal, 2013
The aim of this study was to compare the effect of a 16% carbamide peroxide (CP) gel and a 10% CP gel on mineralized enamel content and morphology. Enamel blocks from bovine incisors were subjected to a 14-day treatment (8 h/day) with 10% or 16% CP gels. Knoop microhardness was evaluated before bleaching and at 1, 7 or 14 days after this treatment (50 g/15 s). Mineral content (energy-dispersive x-ray spectroscopy), surface roughness and topography (atomic force microscopy) were evaluated at the 14-day period. Data were analyzed statistically by two-way ANOVA and Tukey's test (α=0.05). Significant microhardness reduction was observed at the 7 th and 14 th days for 10% CP gel, and for all bleaching times for 16% CP gel (p<0.05). At the 14-day period, a significant decrease in Ca and P content, increase on surface roughness (p<0.05) as well as on picks and valleys distance were observed when both bleaching gels were used. These enamel alterations were more intense for 16% CP gel. It was concluded that both CP-based gels promoted loss of mineral structure from enamel, resulting in a rough and porous surface. However, 16% CP gel caused the most intense adverse effects on enamel.