• Journal of dental hygiene science
• /
• v.13 no.2
• /
• pp.191-196
• /
• 2013

The purpose of this study was to evaluate the tooth brightening of whitening dentifrice and to determine the tooth stain level over 20 days depending on beverages that have various pH values after using whitening dentifrice. Thirty teeth were randomly divided into two groups. Group 1 was provided with a whitening dentifrice for 3 minutes and group 2 was treated with a control dentifrice for 3 minutes thrice a day for four weeks. All teeth were photographed using a digital imaging system under a stereomicroscope (magnification, ${\times}10$). After four weeks, the ten teeth were immersed in the tea solution, another of ten teeth were immersed in the orange juice and the other of the teeth were immersed in the coffee solution. Three solutions were renewed each day for the appropriate groups. Stain development was monitored under a stereomicroscope daily over 20 days period by immersion of teeth in a tea, juice, coffee solution at room temperature ($25^{\circ}C$) in individual container. Whitening dentifrice gave a statistically higher value of overall color change as compared to control dentifrice after 21 days (p<0.05). Stain level of whiten tooth immersed in orange juice was the grestest overall color change, but there was not statistically significant difference (p>0.05). On the other hand, stain level of whiten tooth immersed in coffee and green tea showed a statistically significant difference after 15 days and 5 days, respectively (p<0.05). Tooth immersed in green tea was higher negative value than control dentifrice. The tooth using whitening dentifrice was shown to be effectively whiter color than control dentifrice. However, stain level by orange juice, coffee and green tea has a strong staining effect.

• Restorative Dentistry and Endodontics
• /
• v.44 no.1
• /
• pp.6.1-6.11
• /
• 2019

Objectives: The aim of the present study was to evaluate the effect of whitening mouth rinses alone and in combination with conventional whitening treatments on color, microhardness, and surface roughness changes in enamel specimens. Materials and Methods: A total of 108 enamel specimens were collected from human third molars and divided into 9 groups (n = 12): 38% hydrogen peroxide (HP), 10% carbamide peroxide (CP), 38% HP + Listerine Whitening (LW), 10% CP + LW, 38% HP + Colgate Plax Whitening (CPW), 10% CP + CPW, LW, CPW, and the control group (CG). The initial color of the specimens was measured, followed by microhardness and roughness tests. Next, the samples were bleached, and their color, microhardness, and roughness were assessed. Data were analyzed through 2-way analysis of variance (ANOVA; microhardness and roughness) and 1-way ANOVA (color change), followed by the Tukey post hoc test. The Dunnett test was used to compare the roughness and microhardness data of the CG to those of the treated groups. Results: Statistically significant color change was observed in all groups compared to the CG. All groups, except the LW group, showed statistically significant decreases in microhardness. Roughness showed a statistically significant increase after the treatments, except for the 38% HP group. Conclusions: Whitening mouth rinses led to a whitening effect when they were used after conventional treatments; however, this process caused major changes on the surface of the enamel specimens.

• Restorative Dentistry and Endodontics
• /
• v.31 no.6
• /
• pp.470-476
• /
• 2006

The objective of this in situ study was to evaluate the effects of whitening strip (Claren, LG Household & Health Care Ltd, 2.6% hydrogen peroxide) and gel (Opalescence, Ultradent, 10% carbamide peroxide) on microhardness of enamel in comparison with untreated control. Extracted twenty human upper incisors were disinfected, cleaned, and labial side of each incisor sectioned into 3 fragments by 2 ${\times}$ 2 mm size. After sectioning, labial sides of fragments were flattened and fixed to orthodontic bracket using flowable composite resin. Specimens prepared from each tooth were attached to the labial side of upper incisors of twenty volunteers one by one and treated by three different methods: (1) untreated control (2) treated with whitening strip for 14 days (3) treated with whitening gel for 14 days. Microhardness (Microhardness tester, Zwick) of each specimen was measured at the baseline of pre-treatment, immediate after bleaching treatment, 14 days after bleaching treatment and Knoop Hardness Number was determined. Microhardness changes of experimental groups were compared. The results show that tooth whitening strip and gel used in this study does not effect the microhardness of enamel during bleaching procedure.

• Restorative Dentistry and Endodontics
• /
• v.29 no.3
• /
• pp.219-225
• /
• 2004

This study evaluated the microshear bond strength of composte resin to teeth bleached with commercial whitening strips and compared with those bleached with home bleaching gel. Twelve extracted human central incisors were cut into pieces and central four segments were chosen from each tooth and embedded in acrylic resin. Four blocks with 12 tooth segments embedded in acrylic resin were acquired and numbered from group one to group four. Group 1 was bleached with Crest Whitestrips, group 2 with Claren, group 3 with Opalescence tooth whitening gel (10％ carbamide peroxide). Group 4 was used as control. The bleaching procedure was conducted for 14 days according to the manufacturer's instructions ; the bleaching strips twice a day for 30 min and the bleaching gel once a day for 2hr. After bleaching, composite resin (Filtek Supreme) was bonded to the enamel surfaces with a self-etching adhesive (Adper Prompt L-Pop) using Tygon tube. Microshear bond strength was tested with a universal testing machine (EZ-test). The data were statistically analysed by one-way ANOVA. The study resulted in no statistical differences in microshear bond strength between the tooth segments bleached with 2 different whitening strips and bleaching gel. It can be concluded that the effect of bleaching with either commercial whitening strips or bleaching gel on enamel is minimal in bonding with self-etching adhesive to composite resin.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.10
• /
• pp.4717-4724
• /
• 2012

This study is to examine the relation between Korean fermented food and discoloration on teeth, which have undergone profession tooth whitening. The color change of natural tooth, which has undergone professional tooth whitening, is objectively measured by dental colorimeter after being immersed in Korean fermented food for certain period. The tooth specimens used in this study are 30 pieces and measured 30 times per one tooth, 900 times totally by dental colorimeter ShadeEye NCC$^{(R)}$ Dental Chroma Meter. As a result of analyzing the collected data by using PASW(statistical package) 18.0, the significant difference is found (p<0.001) in lightness and yellowness before and after of professional tooth whitening. The lightness and yellowness after immersion is changed (p<0.001) according to time. As a result of examining the degree of discoloration based on type of fluids, the similar difference is indicated (p=0.001, p<0.001 1,2 and 3 weeks after getting professional tooth whitening. As a result, Korean traditional fermented food influences on discoloration on bleached tooth depended on the duration of immersion and the type of fluids. However, this study failed to represent internal oral condition accurately therefore the results of this study could be altered by the internal oral condition, frequency of consumption of food, and the management oral hygiene.

• Journal of dental hygiene science
• /
• v.13 no.1
• /
• pp.13-19
• /
• 2013

This study evaluated the change of color and the microhardness according to time-out using the office bleaching with in vitro test after bleaching one time 1 day per week, total three times, for the control group and three times per 1day for the experimental group. $L^*$ was increased in both groups. Group 1 showed a significant increase statistically between before and after tooth whitening (p<0.05). Group 2 showed a significant increase statistically between before and after tooth whitening (p<0.05). ${\Delta}E^*$ was huge in both groups. In group 1, it was great in terms of statistical significance between 1 day and 7 days after tooth whitening (p<0.05). In group 2, it was the greatest between before and 1 day after tooth whitening and was significant statistically as well (p<0.05). Vickers hardness number (VHN) decreased in both groups. In group 1, VHN decreased over time and the difference was significant statistically (p<0.05). In group 2, VHN decreased over time and the difference was significant statistically (p<0.05). Percentage microhardness loss was great in both groups. In group 1, it was the greatest between 1 day and 7 days after the treatment, and it was significant statistically (p<0.05). In group 2, it was the greatest between before and 1 day after the treatment, and it was significant statistically (p<0.05). Put together, the more frequent tooth whitening a day is, the longer the period of tooth whitening when applying the same frequency, the greater color change was, however the microhardness decreased, in regard to the results over time using 15% hydrogen peroxide tooth whitening product for professionals.

• Proceedings of the KACD Conference
• /
• 2003.11a
• /
• pp.573-573
• /
• 2003

I. Objective This study evaluated the microshear bond strength of teeth bleached with commercial whitening strips and compared with those bleached with home bleaching gel. II. Materials and Methods Twelve exrtacted central incisors were cut into pieces and central four segments were chosen from each tooth and embedded in acrylic resin. Four blocks with 12 tooth segments embedded in acrylic resin were acquired and numbered from one to four. Block 1 was bleached with Crest Whitestrips, block 2 with Claren, block 3 with Opalescence tooth whitening gel(10% carbamide peroxide).(omitted)

• The Journal of the Korea Contents Association
• /
• v.10 no.11
• /
• pp.235-242
• /
• 2010

The purpose of this study was to evaluate tooth whitening and microhardness after treatments with tooth bleaching agents containing dicalcium phosphate dihydrate (DCPD) and 35% hydrogen peroxide (HP) which were used in-office bleaching. Thirty enamel specimens were obtained from human premolars and randomly divided into 3 groups(n=10). Tooth bleaching agents were prepared with DCPD (0 g for controls, 0.1 g and 1 g for experimental groups) and HP solution (35% HP). All groups were applied to enamel surfaces for 60 min for 1 day. The pH of each tooth bleaching agent was measured. Tooth color, microhardness of enamel surfaces were also measured. The tooth bleaching agents containing DCPD showed a significant increase in pH compared to the ones without DCPD(p<0.05). Paired t-tests showed significant difference in color values of enamel before and after bleaching in all the groups(p<0.05). As a result, changes in color, containing DCPD group does not contain a statistically significant difference between groups was observed.(p>0.05). In all groups, tooth hardness after bleaching showed a significant decrease in microhardness (p<0.05). However, the DCPD concentration increased in the bleaching, microhardness values slightly decreased. Based on the above results, tooth bleaching agents containing DCPD and 35%HP were equally effective. Due to increases in pH and effective reduction of tooth surface decalcification, the surface characteristics are exposed to a reduced degree of negative effects, resulting in fewer constituent enamel alterations. Thus, commercial availability of the constituents of tooth whitening materials can be achieved.

• Journal of Korean society of Dental Hygiene
• /
• v.14 no.1
• /
• pp.101-108
• /
• 2014

Objectives : The purpose of this study was to evaluate the tooth whitening effect of 0.74% and 2.80% hydrogen peroxide toothpastes and safety on tooth and gingival tissue. Methods : Toothpastes containing 0.74% and 2.80% hydrogen peroxide were evaluated. In in-vitro test, some additives (sodium metaphosphate, sodium pyrophosphate and titanium dioxide) were added to the toothpastes. Hydroxyapatite specimens (HAPs) were made and stained using modified Stookey's methods. HAPs were treated for 1 hour at shaking incubator and brushed for 1,000 times as 250 gF with each diluted toothpaste. Before and after color was measured by colorimeter. Using double blind method, 99 Korean with natural maxillary anterior teeth were selected and the initial brightness (baseline) was measured by SHADEEYE-EX. Based on this measurement they were crossly distributed into control group (0% hydrogen peroxide), test 1 (0.74% hydrogen peroxide) and test 2 (2.80% hydrogen peroxide). After 2 weeks, people of each group were provided toothpaste and told to use 3 times a day right after every meal for 3 minutes. The brightness of teeth was measured 3 times for every one month. Results : ${\Delta}L$ was statistically significant among three groups in shaking test. ${\Delta}L$ of two test groups was statistically significant compared with control group but not between each test group in brushing test. After using toothpaste for 3 months, test 1 group and test 2 group were 15.89% and 31.23% more whitened compared with control group respectively (p<0.05). Rate of more whitened person of each test group was 24.2% and 40.5% more than control group respectively (p<0.05). There was no difference in the hypersensitivity during 3 months using toothpastes and no side effect on teeth or gums. Conclusions : Toothpastes containing 0.74% and 2.80% hydrogen peroxide showed tooth whitening effect and both were safe enough to use for tooth whitening.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.44 no.1
• /
• pp.1-10
• /
• 2017

The present study aimed to evaluate the validity of resin infiltration in improving color stability after tooth whitening. Enamel samples were extracted from 40 healthy bovine upper incisors, and primary staining and whitening were performed. After that, specimens were randomly divided into 3 groups : resin infiltration group (n = 15, RI group), resin adhesive group (n = 15, RA group), and control group (n = 10). Secondary staining was performed on all samples. Coloration was assessed 5 times as follows: initial color, immediately after staining, after whitening, after resin application, and after secondary staining. Color was measured using a spectrophotometer and recorded by using the CIE $L^*a^*b^*$ color space. The color changes after primary staining for the RI, RA, and control groups were $12.16{\pm}3.50$, $12.16{\pm}3.38$, and $15.81{\pm}6.39$, whereas those after secondary staining were $15.21{\pm}7.19$, $15.93{\pm}4.31$, and $26.62{\pm}17.89$. Color changes after secondary staining showed a significant difference between the RI and control groups. In the within-group comparison between primary and secondary staining, there was no significant difference found in the RI group only (p = 0.26). The results suggest that Color stability after tooth whitening can be improved using resin infiltration.