<h4>Objectives</h4>To review current knowledge with respect to tooth colour and its measurement.<h4>Methods</h4>'Medline' database for the period 1966 to the present day and 'ISI Web of Science' database for the period 1974 to the present day were searched electronically with key words tooth, teeth, colour and color.<h4>Conclusions</h4>The colour and appearance of teeth is a complex phenomenon, with many factors such as lighting conditions, translucency, opacity, light scattering, gloss and the human eye and brain influencing the overall perception of tooth colour. The measurement of tooth colour is possible via a number of methods including visual assessment with shade guides, spectrophotometry, colourimetry and computer analysis of digital images. These methods have successfully been used to measure longitudinal tooth colour changes when the dentition has undergone tooth whitening procedures.

<h4>Background</h4>With the increased demand for whiter teeth, home-based bleaching products, either dentist-prescribed or over-the-counter products have been exponentially increasing in the past few decades. This is an update of a Cochrane Review first published in 2006.<h4>Objectives</h4>To evaluate the effects of home-based tooth whitening products with chemical bleaching action, dispensed by a dentist or over-the-counter.<h4>Search methods</h4>Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 12 June 2018), the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 6) in the Cochrane Library (searched 12 June 2018), MEDLINE Ovid (1946 to 12 June 2018), and Embase Ovid (1980 to 12 June 2018). The US National Institutes of Health Ongoing Trials Register ClinicalTrials.gov (12 June 2018) and the World Health Organization International Clinical Trials Registry Platform (12 June 2018) were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases.<h4>Selection criteria</h4>We included in our review randomised controlled trials (RCTs) which involved adults who were 18 years and above, and compared dentist-dispensed or over-the-counter tooth whitening (bleaching) products with placebo or other comparable products.Quasi-randomised trials, combination of in-office and home-based treatments, and home-based products having physical removal of stains were excluded.<h4>Data collection and analysis</h4>Two review authors independently selected trials. Two pairs of review authors independently extracted data and assessed risk of bias. We estimated risk ratios (RRs) for dichotomous data, and mean differences (MDs) or standardised mean difference (SMD) for continuous data, with 95% confidence intervals (CIs). We assessed the certainty of the evidence using the GRADE approach.<h4>Main results</h4>We included 71 trials in the review with 26 studies (1398 participants) comparing a bleaching agent to placebo and 51 studies (2382 participants) comparing a bleaching agent to another bleaching agent. Two studies were at low overall risk of bias; two at high overall risk of bias; and the remaining 67 at unclear overall risk of bias.The bleaching agents (carbamide peroxide (CP) gel in tray, hydrogen peroxide (HP) gel in tray, HP strips, CP paint-on gel, HP paint-on gel, sodium hexametaphosphate (SHMP) chewing gum, sodium tripolyphosphate (STPP) chewing gum, and HP mouthwash) at different concentrations with varying application times whitened teeth compared to placebo over a short time period (from 2 weeks to 6 months), however the certainty of the evidence is low to very low.In trials comparing one bleaching agent to another, concentrations, application method and application times, and duration of use varied widely. Most of the comparisons were reported in single trials with small sample sizes and event rates and certainty of the evidence was assessed as low to very low. Therefore the evidence currently available is insufficient to draw reliable conclusions regarding the superiority of home-based bleaching compositions or any particular method of application or concentration or application time or duration of use.Tooth sensitivity and oral irritation were the most common side effects which were more prevalent with higher concentrations of active agents though the effects were mild and transient. Tooth whitening did not have any effect on oral health-related quality of life.<h4>Authors' conclusions</h4>We found low to very low-certainty evidence over short time periods to support the effectiveness of home-based chemically-induced bleaching methods compared to placebo for all the outcomes tested.We were unable to draw any conclusions regarding the superiority of home-based bleaching compositions or any particular method of application or concentration or application time or duration of u

<h4>Objectives</h4>This research evaluated efficacy and safety of 6% hydrogen peroxide whitening strips from a clinical trials database accumulated over a multi-year period at a single site.<h4>Methods</h4>The inclusive meta-analysis involved seven different randomized clinical trials at one dental school. Each study used 6% hydrogen peroxide whitening strips twice daily for 30min over a 2-week period. Common efficacy (digital images) and safety (examination and interview) methods were used across studies. Pooled subject-level data were analyzed using a general linear mixed model to determine overall response and effects of treatment duration on whitening.<h4>Results</h4>The 148 treated subjects were 18-71 years old, with b* (yellowness) ranging from 12 to 22, and L* (lightness) ranging from 69 to 80. After 1-week strip use, the adjusted mean (S.E.) for Deltab* was -1.6 (0.08), differing significantly from baseline (p<0.0001). After 2 weeks, the adjusted mean (S.E.) for Deltab* was -2.3 (0.07), differing significantly from Week 1 (p<0.0001). The estimated correlation between Weeks 1 and 2 for Deltab* was 0.74. Study-to-study variation contributed less than 2% of Deltab* variability. Results were similar for DeltaL*, with Weeks 1 and 2 estimated means (S.E.) of 1.5 (0.13) and 2.0 (0.12). Occurrence of oral irritation (22%) and tooth sensitivity (20%) did not adversely affect whitening. Other side effects were unremarkable, and only 1 subject (0.7%) discontinued treatment early due to an adverse event.<h4>Conclusions</h4>The meta-analysis of multiple studies conducted at a single clinical site over several years establishes consistent, effective and safe vital bleaching with 6% hydrogen peroxide whitening strips.

<h4>Introduction</h4>Common clinical experience suggests that tooth whitening agents are 100% effective. This study uses meta-analysis of data from published randomized controlled clinical trials to determine the efficacy of tooth whitening agents.<h4>Methods</h4>A MEDLINE search strategy was developed and implemented to systematically identify clinical trials on dentist-prescribed, home-applied tooth whitening agents, using 10% carbamide peroxide, published between 1989-1999. Inclusion criteria (e.g., in English, human clinical trials) and exclusion criteria (e.g., not placebo controlled) were established and clinical trials that met these criteria were critically appraised for validity and clinical applicability. Meta-analysis was then used to quantitatively integrate the findings.<h4>Results</h4>Seven studies were identified that met the inclusion and validity criteria. These studies indicated that: Whitening results in a significant mean change of 6 4 shade guide units (p < 0.01), while the placebo control group exhibited little change (0.7 0.6, p > 0.05). 93% of the bleached patients exhibited 2 shade guide unit change, while 20% of the placebo control group exhibited this change. The brand of bleaching agent had a significant effect on tooth whitening, but the daily application time and duration of treatment did not. Whitening is maintained for 6 months for 1/2 of the people treated. Neither gingival indices nor plaque indices were adversely or favorably affected by bleaching. CLINICAL APPLICABILITY: The data from the reviewed studies indicate that rather than being 100% effective, on average: 73% (93% for bleached group minus 20% placebo group) of people who whiten their teeth will exhibit a whitening that is 2 shade guide units greater than the placebo. 20% of the people who use dentist-prescribed, home-applied bleaching will achieve a mean whitening effect of 5 shade guide units. Re-treatment for 50% of people may be necessary to maintain this effect longer than 6 months. The methods used here are Internet applicable for other clinical topics.

Abstract The objectives were to determine the color distribution of natural teeth sorted by the parameters of Value, Chroma, and hue angle measured with a colorimeter, and to suggest a shade guide model. The color of maxillary and mandibular 12 anterior teeth was measured with a tristimulus colorimeter for 47 subjects (n = 564). The color of teeth was grouped initially by Value (CIE L*) by the interval of 3.3 units. After then, within each main group, the color of teeth was subgrouped by Chroma by the interval of 3.3 units. Chroma was calculated as C * ab = ( a *2 + b *2) 1/2 . Since the hue angles were in the first or fourth quadrant, subgroups were further sorted by the first or fourth quadrant hue angles. Hue angle was calculated as h° = arctan (b*/a*). Mean color difference (Δ E * ab ) between the color of an individual tooth and the mean color of each main group was 2.5–3.3, which was lower than acceptable limit (Δ E * ab &lt; 3.3), and that in each subgroup was 0.9–3.1. The number of subgroups was 22, which was comparable to those of conventional shade guides. A shade guide model based on the color distribution of natural teeth sorted by Value in six main groups, three or four subgroups within each main group sorted by Chroma, and further sorted by hue angle (first or fourth quadrant values) was suggested. © 2007 Wiley Periodicals, Inc. Col Res Appl, 32, 278–283, 2007

Carbamide and orthophosphoric acid were utilized for whitening of immature fluorosis teeth. Microabrasion in children's teeth was effective in combination with following fluoridation, for example Tooth Moose. Direct and indirect restorations are considered the treatment of choice for moderate to severe cases of fluorosis given the optimum aesthetics, wear resistance, biocompatibility, and long-term results. Whereas veneers and crowns are indicated in mature fluorosis teeth, choice of direct composite restorations doesn’t depend on tooth maturity. Treatment of fluorosis of various severities in children should include endogenous use of medicines that increase the enamel remineralisation. Local remineralisation therapy is indicated for mild fluorosis in immature teeth and for moderate fluorosis in combination with bleaching and microabrasion. Infiltration technique is recommended for mild fluorosis management and in combination with whitening for moderate fluorosis treatment in children. In the case of inefficiency of minimally invasive methods or severe fluorosis, direct or indirect restorations are conducted.

Veneers are porcelain or ceramic linings that replace the outer layer of teeth. They allow you to correct irregularities in the shape and color of the tooth, and also protect your teeth (for example, when playing wind instruments). Veneers are made according to the shape and color of the patient's teeth and their wishes.

Current developments in esthetic dentistry. Current developments in esthetic dentistry center around new techniques and materials that improve the clinician's ability to provide esthetic services. These developments include the availability of improved composites for anterior and posterior use, a new generation of dentin bonding agents, bonded ceramic restorations, and more efficient and predictable ways to whiten teeth. There is a better understanding of factors contributing to the esthetic value of restoration as well as their longevity. New bonding techniques to dentin enable practitioners to perform difficult restorative procedures in a conservative manner, producing results that are highly esthetic and physiologically tolerable. The use of dental porcelains has expanded from the traditional applications in crowns and bridges to veneers, inlays, onlays and all-porcelain bridges that are directly bonded to teeth. Computer-designed and fabricated inlays and onlays are now an available treatment modality, with a reported 3-years follow-up looking very promising.