Review of the Mechanism of Tooth Whitening Kwon, So Ran; Wertz, Philip W.
Journal of esthetic and restorative dentistry,
September/October 2015, Letnik:
27, Številka:
5
Journal Article
Recenzirano
Purpose
This review integrated the current literature on diffusion of whitening agents, their interactions with stain molecules, and changes to the surface, with the aim of establishing a better ...understanding of the mechanism underlying tooth whitening.
Materials and Methods
An electronic PubMed database search, with combinations of the following terms was performed: Tooth Bleaching, Tooth Bleaching Agent, Hydrogen Peroxide, Pharmacokinetics, Tooth Permeability, Oxidation‐Reduction, Tooth Demineralization, and Color.
Results
Tooth whitening is a dynamic process that involves diffusion of the whitening material to interact with stain molecules and also involves micromorphologic alterations on the surface and changes within the tooth that affect its optical properties. The interaction seems not to be limited to stain molecules, but rather an affinity‐based interaction process that also accompanies effects on sound enamel and dentin structures.
Conclusions
This review underlines that supervision by dental health professionals as recommended by the American Dental Association (ADA) Council on Scientific Affairs is critical to achieving a successful and safe whitening outcome.
Clinical Significance
The mechanism that underlies tooth whitening with the use of peroxide‐based materials is a complex phenomenon encompassing diffusion, interaction, and surfaces changes within the tooth. Therefore, supervision by dental health professionals as recommended by the ADA Council on Scientific Affairs is imperative to achieve a successful and safe whitening outcome.
Tooth‐erosion is the surface loss of dental hard tissue mostly associated with an acid attack. The aim was to compare dentin and enamel erosion depth measurements using micro‐computed tomography ...(microCT) and light microscopy (LM). Enamel/dentin blocks were prepared from caries‐free human molar‐teeth (N = 12). Teeth were sectioned to a rectangular shape of 4 × 4 × 6 mm. Specimens were treated with water (NC) or 1.0% citric‐acid solution (PC). After treatment, specimens were scanned with micro‐computed tomography. On completion, specimens were sectioned and observed under a light‐microscope. Lesion depth was observed with 10× magnification and images transferred to Simpleware software. Vertical distance from lesion surface to bottom was measured. Pearson correlation test was used to evaluate correlation and Wilcoxon Signed Rank test to evaluate differences in the two‐analysis methods. Mean enamel erosion depth was 0.63 and 38.38 μm (microCT) and 0.54 and 39.43 μm (LM) for NC and PC, respectively. Dentin erosion depth was 0.72 and 48.05 μm (microCT) and 0.56 and 49.92 μm (LM) for NC and PC, respectively. There was a significant correlation between the two‐analysis methods (r = 0.998; p < .001). No statistically significant difference in results were obtained when microCT and LM were compared (p = .584). This results obtained from the current study suggested that erosion depth measurements made using microCT and LM yielded comparable results. The microCT method is preferred if the conservation of specimens is desired.
It is indicated a combination of techniques to address limitations inherent of each one to analyze erosion, we believe microCT as a non‐destructive and three‐dimensional technique should be add as a potential method for exploring erosion, due to there is not yet a well‐established technique to quantifying the degree of demineralization and surface‐loss. The use of microCT for research has huge potential but is still under‐utilized, partly due to lack of knowledge of the capabilities and how it can be used in the different fields. We hope this study fuels further advances in this field using microCT.
ABSTRACTBackground The periodontal probe is an essential instrument designed for the purposes of recording clinical periodontal data. As such, accurate periodontal measurements remain a critical ...factor in providing individualized care to patients. The purpose of this study is to determine the compatibility and accuracy of three different periodontal probes on a periodontal typodont model.Materials and Methods Forty-one D3, D4, and DH students were randomly selected to perform a 6-point pocket depth measurement on the mandibular teeth of a previously verified periodontal typodont mounted on a manikin. Each measurement site was outlined with black marking on the tooth to facilitate consistent reproducibility in periodontal probe placement and angulation.Results Probing depth measurements between the UNC-15, PCP-126, and Disposable i-PAK® periodontal probe rendered an excellent equivalency (ICC = 0.960) with narrow CI (0.947, 0.971). There is significant difference among these three instruments in their capability to replicate the manufacturer’s suggested probing depth on the periodontal typodont (p < .001). The UNC-15 probe was the most accurate, followed by PCP-126, with the Disposable i-PAK® being the least accurate.Conclusions This study demonstrated that the UNC-15, PCP-126, and Disposable i-PAK® yielded equivalent results when measuring probing depths on a periodontal typodont. Furthermore, the UNC-15 was most accurate in its ability to replicate the manufacturer’s suggested pocket depth on the periodontal typodont.Practical Implications This study emphasizes the importance in consistency of periodontal probe types in the dental practice.
The aim of this study was to evaluate the effect of digital tooth preparation imaging and evaluation technology on dental students’ technical abilities, self‐evaluation skills, and the assessment of ...their simulated clinical work. A total of 80 second‐year students at one U.S. dental school were assigned to one of three groups: control (n=40), E4D Compare (n=20), and Sirona prepCheck (n=20). Students in the control group were taught by traditional teaching methodologies, and the technology‐assisted groups received both traditional training and supplementary feedback from the corresponding digital system. Three outcomes were measured: faculty technical score, self‐evaluation score, and E4D Compare scores at 0.30 mm tolerance. Correlations were determined between the groups’ scores from visual assessment and self‐evaluation and between the visual assessment and digital scores. The results showed that the visual assessment and self‐evaluation scores did not differ among groups (p>0.05). Overall, correlations between visual and digital assessment scores were modest though statistically significant (5% level of significance). These results suggest that the use of digital tooth preparation evaluation technology did not impact the students’ prosthodontic technical and self‐evaluation skills. Visual scores given by faculty and digital assessment scores correlated moderately in only two instances.
ABSTRACTBackground 3D printed implant surgical guides are designed to improve implant placement accuracy. However, they are a potential source of contamination during implant surgery and therefore ...require sterilization to prevent post-surgical infection. This study evaluated the effect that steam sterilizing 3D printed implant surgical guides has on the accuracy of fully guided implant placement.Methods 3D printed models were prepared with an edentulous site at the right maxillary central incisor. A surgical guide was designed and fabricated to place a bone level implant at this edentulous site. Ten implants were placed with surgical guides, followed by ten placed with the same guides after autoclave sterilization at 134°C for 6 minutes. Implants were scanned and analyzed using three-dimensional analysis software. The implant platform position, apex position, and angulation were evaluated before and after sterilization of the surgical guides.Results There were statistically significant deviations of implant platform and apex in the x-axis (bucco-lingual), y-axis (mesio-distal), and implant angulation (Wilcoxon signed-rank test, p < .05). There was no statistically significant deviation in the occluso-gingival height of the implant.Conclusions Steam sterilization has a statistically significant effect on the accuracy of fully guided implant placement using 3D printed surgical guides. The buccolingual deviation of the implant apex is clinically significant (mean = 1.22 mm).Practical Implications Dentists should exercise caution when using steam heat (i.e. autoclaving) to sterilize 3D printed implant surgical guides. Alternative options such as cold sterilization may be more appropriate.Continuing Education Credit Available The practice worksheet is available online in the supplemental material tab for this article. A CDA Continuing Education quiz is online for this article: https://www.cdapresents360.com/learn/catalog/view/20.
Abstract Objectives To determine the effect of light activation on tooth whitening efficacy and hydrogen peroxide penetration into the pulp cavity and correlate tooth color change with penetration ...levels. Methods Extracted human canines (40) were randomized into four groups, Group A: placebo gel, Group B, placebo gel with light activation, Group C: 40% hydrogen peroxide gel, and Group D: 40% hydrogen peroxide gel with light activation. Treatment was performed three times, at 1-week intervals. Hydrogen peroxide penetration (HPP) was estimated spectrophotometrically and specimen color measured using the Vita Easy Shade Compact at baseline, after whitening, 1-h, 1-day, 1-, 4-, 8-, 12-, 16-, 20-, and 24-week post-whitening. Color change was measured per Commission Internationale de l’Eclairage methodology. ANCOVA was performed to compare color change and HPP level among the four groups. Partial nonparametric correlations between color change and HPP levels were performed with rank transformations. Tests of hypotheses were two-sided with alpha level of 0.05. Results Greater HPP was observed in Groups C and D compared to Groups A and B ( p < 0.001). Highest overall color change (Δ E *ab) values after treatment were observed in Group D and remained higher than Groups A–C ( p < 0.01). Changes in lightness and in the yellow-blue dimension (Δ L * and Δ b *) were higher in Groups C and D compared to Groups A and B from post-whitening until 24 weeks ( p < 0.05). HPP levels were not correlated to color change ( p > 0.05). Conclusions Light activation enhanced whitening efficacy without affecting hydrogen peroxide penetration levels.
Abstract The purpose of this study was to evaluate the effect of four whitening modalities on surface enamel as assessed with microhardness tester, profilometer, and scanning electron microscopy ...(SEM). Whitening was performed according to manufacturer's directions for over-the-counter (OTC), dentist dispensed for home use (HW) and in-office (OW) whitening. Do-it-yourself (DIY) whitening consisted of a strawberry and baking soda mix. Additionally, negative and positive controls were used. A total of 120 enamel specimens were used for microhardness testing at baseline and post-whitening. Following microhardness testing specimens were prepared for SEM observations. A total of 120 enamel specimens were used for surface roughness testing at baseline and post-whitening (n = 20 per group). Rank-based Analysis of Covariance was performed to compare microhardness and surface roughness changes. Tests of hypotheses were two-sided with α = 0.05. There was a significant difference in Knoop hardness changes (ΔKHN) among the groups (Kruskal-Wallis test, p < 0.0001). Significant hardness reduction was observed in the positive control and DIY group (p < 0.0001). Mean surface roughness changes (ΔRa) were significantly different among the groups (Kruskal-Wallis test, p< 0.0001). Surface roughness increased in the OTC group (p = 0.03) and in the positive control (p < 0.0001). The four whitening modalities - DIY, OTC, HW and OW induced minimal surface morphology changes when observed with SEM. It can be concluded that none of the four whitening modalities adversely affected enamel surface morphology. However, caution should be advised when using a DIY regimen as it may affect enamel microhardness and an OTC product as it has the potential to increase surface roughness.
This study aimed to use a laboratory model to evaluate the efficacy of an experimental bleaching agent.
The model used human extracted molars that were treated and measured for bleaching efficacy. ...Teeth (
= 50) were distributed into 5 groups: Negative control (NC): immersion in water for 8 hours; Nanofibers (NFs): Experimental titanium dioxide nanofibers with stirring and light activation for 8 hours; Whitestrips (WS): Crest 3D White Glamorous White Whitestrips, 2 applications daily for 30 minutes, 14 days; 1% hydrogen peroxide (HP) standard: 1% hydrogen peroxide for 8 hours; and 30% HP standard: 30% hydrogen peroxide for 8 hours. Instrumental measurements were performed using a spectrophotometer. Results were recorded at baseline, 1-day post-bleaching, and 1-week post-bleaching. Kruskal-Wallis procedure was used to determine differences in color change. Pearson correlation was used to evaluate the relationship between visual and instrumental measurements. Tests of hypotheses were 2-sided with alpha = 0.05.
There was no significant difference in color parameters (L1, a1, b1, and shade guide units SGU) at baseline (
> 0.05). There was a significant difference among the groups for overall color change (ΔE*ab) and change in shade guide units (ΔSGU) at 1-day and 1-week post-bleaching (
< 0.05). The higher the HP concentration, the higher the color change as expressed in ΔSGU and ΔE*ab. The negative control exceeded the perceptibility threshold of ΔE* = 1.2 regardless of time point. NFs showed a decrease in chroma, but were not statistically different compared to the negative control.
The laboratory model was successful in screening an experimental bleaching agent.
ABSTRACT
Purpose
To evaluate the whitening efficacy of a new two‐layer technology in‐office system compared to a conventional gel‐type system and determine hydrogen peroxide penetration (HPP) into ...the pulp cavity.
Materials and Methods
Extracted molars (n = 60) were assigned to group NC: glycerol gel; group QPRO: 20% HP varnish (Zoom Quick Pro, Philips Oral Healthcare); group ZOOM_NL: 25% HP gel (Zoom Chairside Whitening); and group ZOOM_WL: 25% HP gel (Zoom Chairside Whitening) with light‐activation. HPP levels were estimated with leucocrystal‐violet and horseradish‐peroxidase. Instrumental color measurements were performed at baseline (T0), 1‐day post first whitening (T1), 1‐day post second whitening (T2), 1‐day post third whitening (T3), and 1‐month post whitening (T4). One‐way analysis of variance followed by post hoc Tukey's HSD test was performed to detect difference in ΔE* and HP penetration levels (α = 0.05).
Results
ΔE* of NC was lower than other groups, whereas ΔE* of ZOOM_WL was greater than the other three groups, at T3 and T4. Mean HPP level obtained from ZOOM_WL (1.568 ± 0.753 μg/mL) was significantly greater than those obtained from the other groups, whereas the mean HPP level observed in NC group (−0.131 ± 0.003 μg/mL) was significantly lower than the other groups.
Conclusions
Tooth whitening efficacy and HPP levels vary based on whitening systems used.
CLINICAL SIGNIFICANCE
The two‐layer technology in‐office varnish system may be an alternative whitening option to reduce chair time in the office. (J Esthet Restor Dent 28:313–320, 2016)
Objective
To assess the relationship between oral health knowledge and oral health related quality of life among older adults with different ethnicities living in San Bernardino County, California. ...There is a gap in oral health knowledge (OHK) and how it relates to perceived oral health related quality of life. Thus, there is a need to assess OHK as a component of oral health literacy and identify areas in which knowledge gaps exit to develop educational strategies that address the need of the elderly population.
Materials and Methods
The study was a cross‐sectional study that included adults 65 years and older using a validated “Comprehensive Measure of Oral Health Knowledge” (CMOHK) and an “Oral Health Profile Index” (OHIP‐14). Odds ratios were conducted to determine the factors associated with OHK.
Results
Mean OHK score were 16.8, 14.6, and 8.9 for Caucasian, Asian, and Hispanics, respectively. “Poor” OHK was significantly associated with participants over the age of 75 years (OR = 1.9; 95% CI: 1.15–3.16), high school education or less (OR = 10.8; 95% CI: 5.92–19.84), minority ethnicity (OR = 7.3; 95% CI: 4.27–12.61), income less than $25,000 (OR = 10.7; 95% CI: 5.92–19.26), and reading ability less than “Excellent” (OR = 7.27; 95% CI: 4.35–12.14). Mean OHIP‐Severity scores were 7.4, 12.5, and 24.4 for Caucasian, Asian, and Hispanics, respectively. Respondents with Poor OHK were 5.17 times more likely to be identified with high levels of severity (Severity >10).
Conclusion
It is imperative to develop communication strategies to inform older adults on oral health knowledge that provide equal opportunities for all ethnicities.
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