Tooth discolouration and staining: a review of the literature

Stain control with two experimental dentin hypersensitivity toothpastes containing spherical silica: a randomised, early-phase development study

Aims

To determine in human participants whether toothpastes containing small quantities of a novel spherical silica, added to provide enhanced cleaning properties, could achieve similar or greater extrinsic dental stain removal compared to toothpastes containing standard dental abrasive silica concentrations.

Materials and methods

One hundred and twenty-three adults with extrinsic dental stain were randomised to one of four parallel groups for 8 weeks’ twice-daily brushing with an experimental toothpaste containing either 0.5% or 1% spherical silica (with relative dentin abrasivity [RDA] of ~38 and ~58, respectively), or marketed toothpastes containing either 6% (RDA ~ 36) or 16% (RDA ~ 166) standard abrasive silica. The objective was to evaluate the ranking order in extrinsic dental stain removal at Week 8, as measured by MacPherson modification of Lobene stain index Area × Intensity.

Results

Small treatment differences were observed between toothpaste formulations. The ranking order in extrinsic dental stain removal was: experimental 1% spherical silica toothpaste >16% standard abrasive silica toothpaste >6% standard abrasive silica toothpaste >experimental 0.5% spherical silica toothpaste. Toothpastes were generally well tolerated.

Conclusion

This early-phase development study suggests that toothpaste formulations with low concentrations of a novel spherical silica abrasive with high-cleaning capability are generally well tolerated and appropriate for further development.

When to Think of Rickettsia

Rickettsiae are globally encountered pathogens with foci of endemicity and epidemic exacerbations under circumstances of crowding and decline of sanitation. Diagnosis is often missed due to misconceptions about epidemiology, confusing terminology and nonspecific clinical presentation. Rickettsioses should be considered in children with febrile illnesses exceeding the usual duration of a viral infection, in particular in children with rash, lymphadenopathy and nearly normal first-line laboratory tests, who reside in or return from endemic areas, recall a compatible contact history, have a constellation of symptoms starting after an arthropod bite, live under troubled social circumstances, or are part of a cluster of similar cases.

Color change of the bleached enamel treated with calcium silicate- sodium phosphate-sodium monofluorophosphate-based system

Background

The increasing demand of tooth bleaching has also increased the need of researches focusing on the durability of the resultant color. The aim of this study was to evaluate the effect of a system based on calcium silicate, sodium phosphate and sodium monofluorophosphate (Regenerate™) on color maintenance of bleached enamel considering two waiting times for the contact with a cola drink.

Material and Methods

This in vitrostudy was performed on bovine enamel specimens (n = 100), bleached with 35% H2O2 and treated with: G1 Distilled water; G2 Artificial saliva; G3 RegenerateTM Serum and Toothpaste; G4 RegenerateTM Toothpaste; G5 RegenerateTM Serum. The groups G3, G4 and G5 received one application of the respective products for 3 min, in 3 consecutive days. The color parameters (ΔE, L*, a*, b*) were evaluated by spectrophotometry before and after bleaching and after surface treatments and immersion (15min) in cola drink, on the waiting times of 24 hours (T1) and 7 days (T2). The effect of surface treatments and waiting times was evaluated by Two-Way ANOVA, Kruskal-Wallis, Wilcoxon and T test (p<0.05).

Results

There was no significant effect of the surface treatments (p=0.57), waiting times (p=0.97) and their interaction (p=0.47) considering ΔE. The analysis of repeated measures of the color coordinates L*, a* and b* showed a decrease of chromaticity (a*, b*) for G3, G4 and G5 and an increase of lightness (L*) for G5, after immersion in cola drink, suggesting some protection against bleached enamel pigmentation.

Conclusions

RegenerateTM has a potential protective effect on bleached enamel color maintenance. The waiting times of 24 hours and 7 days for the contact with the cola drink did not influence bleached enamel color maintenance.

Key words:Tooth bleaching, hydrogen peroxide, spectrophotometry, pigmentation.

Effect of Whitening Toothpastes on Extrinsic Dental Stains

Aim and objectives:

To compare the effectiveness of the stain removing property of the whitening toothpastes (silica [Colgate Visible White], silica, papain and bromelain [Whitospark], and silica and calcium carbonate [Snowdent] containing toothpastes) on extrinsic dental stains and to assess the lasting of tooth whitening effect produced by the whitening toothpastes.

Materials and methods:

It is a randomized, concurrent parallel arm, non-invasive, controlled trial designed to compare the effectiveness of the whitening toothpastes on reducing extrinsic dental stains. Parametric t-test was used.

Results:

A statistically significant difference can be seen between Groups A and B, Groups B and C, and Groups B and D. Maximum mean and percentage reduction was found in Group B at the end of the second month in stain extent and intensity. A statistically significant difference was seen between subgroups B1 and B2. Maximum mean and percentage reduction was found in subgroup B1 at the end of the fourth month in stain extent and intensity.

Conclusion:

Silica, papain, and bromelain containing toothpastes (Whitospark) show effectiveness on reducing extrinsic dental stains.

Polyphenols Inhibit Candida albicans and Streptococcus mutans Biofilm Formation

Background:Streptococcus mutans (S. mutans) and Candida albicans (C. albicans) are two major contributors to dental caries. They have a symbiotic relationship, allowing them to create an enhanced biofilm. Our goal was to examine whether two natural polyphenols (Padma hepaten (PH) and a polyphenol extraction from green tea (PPFGT)) could inhibit the caries-inducing properties of S. mutans and C. albicans. Methods: Co-species biofilms of S. mutans and C. albicans were grown in the presence of PH and PPFGT. Biofilm formation was tested spectrophotometrically. Exopolysaccharides (EPS) secretion was quantified using confocal scanning laser microscopy. Biofilm development was also tested on orthodontic surfaces (Essix) to assess biofilm inhibition ability on such an orthodontic appliance. Results: PPFGT and PH dose-dependently inhibited biofilm formation without affecting the planktonic growth. We found a significant reduction in biofilm total biomass using 0.625 mg/mL PPFGT and 0.16 mg/mL PH. A concentration of 0.31 mg/mL PPFGT and 0.16 mg/mL PH inhibited the total cell growth by 54% and EPS secretion by 81%. A reduction in biofilm formation and EPS secretion was also observed on orthodontic PVC surfaces. Conclusions: The polyphenolic extractions PPFGT and PH have an inhibitory effect on S. mutans and C. albicans biofilm formation and EPS secretion.

Deionized water can substitute common bleaching agents for nonvital tooth bleaching when treated with non-thermal atmospheric plasma

The bleaching efficacy of common bleaching agents and deionized water treated with non-thermal atmospheric pressure plasma in the pulp chamber for nonvital tooth bleaching was evaluated. A total of 120 extracted human maxillary first incisors were stained using human blood. Teeth were randomly divided into eight groups (n = 15). In the first four groups, teeth were bleached using 35% hydrogen peroxide gel, 37% carbamide peroxide gel, 2:1 (w/v) sodium perborate paste, and deionized water for 30 min. In the remaining groups, bleaching agents were treated with non-thermal atmospheric plasma for 5 min inside the pulp chamber. Overall color changes (∆E) were determined using Commission Internationale de L'Eclairage Lab Colour System. The plasma-assisted tooth bleaching has not increased tooth temperature beyond 37°C. Bleaching efficacies of bleaching agents were significantly improved when treated with non-thermal atmospheric plasma compared to their application (P < 0.05). A remarkable bleaching effect was obtained when bleaching agents were substituted with water and when treated with non-thermal atmospheric plasma. Non-thermal atmospheric plasma treatment could be a novel tool for activation of bleaching agents in the pulp chamber for nonvital tooth bleaching procedure. Moreover, water could be used as a novel bleaching agent when treated with the non-thermal atmospheric plasma to eliminate possible risks which might arise from peroxide-containing agents.

Near-infrared imaging of demineralization on the occlusal surfaces of teeth without the interference of stains

Most new caries lesions are found in the pits and fissures of the occlusal surface. Radiographs have extremely low sensitivity for early occlusal decay, and by the time the lesion is severe enough to appear on a radiograph, it typically has penetrated well into the dentin and surgical intervention is required. The occlusal surfaces are often heavily stained, and visual and tactile detection have poor sensitivity and specificity. Previous near-infrared imaging studies at wavelengths beyond 1300 nm have demonstrated that stains are not visible and demineralization on the occlusal surfaces can be viewed without interference from stains. The objective of our study is to determine how the contrast between sound and lesion areas on occlusal surfaces varies with wavelength from the visible to 2350 nm and determine to what degree stains interfere with that contrast. The lesion contrast for reflectance is measured in 55 extracted teeth with suspected occlusal lesions from 400 to 2350 nm employing silicon and indium gallium arsenide imaging arrays. In addition, the lesion contrast is measured on 25 extracted teeth with suspected occlusal lesions from 400 to 1600 nm in reflectance and from 830 to 1400 nm in transillumination before and after stains are removed using a ultrasonic scaler. The highest lesion contrast in reflectance is measured at wavelengths >1700  nm. Stains interfere significantly at wavelengths <1150  nm (400 to 1150) for both reflectance and transillumination measurements. Our study suggests that the optimum wavelengths for imaging decay in the occlusal surfaces are >1700  nm for reflectance (1700 to 2350 nm) and near 1300 nm (1250 to 1350 nm) for transillumination.

Diagnodent and VistaCam may be unsuitable for the evaluation of dental caries in archeological teeth

OBJECTIVES

The aim of the study was to compare the usefulness of fluorescence-based caries detection systems (Diagnodent and VistaCam) for the assessment of carious lesions on archeological molars.

MATERIALS AND METHODS

The study material consisted of teeth from the Cemetery of St. Mary Magdalene (Cmentarz św. Marii Magdaleny) in Wrocław, Poland. A sample of 178 permanent molars from 38 skulls were examined. Five surfaces of teeth (occlusal, mesial, distal, buccal, and lingual) were assessed on either basically cleaned or sandblasted teeth. Six diagnostic methods were used to detect carious lesions: the visual classification of the International Caries Detection and Assessment System (ICDAS II), fluorescent methods (Diagnodent and VistaCam), X-ray, cone beam computed tomography and histological sections. The sensitivity and specificity of the methods were determined using receiver operating characteristic (ROC) curves and the correlation between the severity of dental caries and the readouts obtained with each method.

RESULTS

In most cases, Diagnodent and VistaCam yielded unsatisfactory specificity and sensitivity values. The area under curve (AUC) values in ROC curves for Diagnodent and Vistacam were lower than the AUC values obtained for the ICDAS II visual classification.

CONCLUSIONS

According to our results, in the case of archeological teeth, neither Diagnodent nor VistaCam can be regarded as a better diagnostic method than the ICDAS II visual classification of caries.

Changes in plaque and gingivitis levels after tooth bleaching: A systematic review

OBJECTIVES

The primary aim of this systematic review was to evaluate the effect of external tooth-bleaching products on plaque indices and to compare it to a placebo or a negative control.

METHODS

A protocol was developed aimed to answer the next focused question: What is the effect of tooth bleaching compared to no treatment or a placebo, in subjects without periodontitis aged ≥18 years in the levels of plaque and gingivitis? Two electronic databases were used as sources in the search for studies satisfying the inclusion criteria: (a) The National Library of Medicine (MEDLINE via PubMed); (b) Cochrane Central Register of Controlled Trials.

RESULTS

Only randomized controlled trials were included. The initial search found 382 potential publications. Seven of them were finally included, and six were used in the meta-analyses. The use of bleaching products showed higher reductions in plaque (n = 6; standardized mean difference [SMD] = 0.47; 95% confidence interval [CI] = 0.06, 0.88; P < 0.001) and gingivitis indices (n = 4; SMD = 0.47; 95% CI = 0.22, 0.73; P < 0.001), when compared to a control group (no treatment or placebo).

CONCLUSIONS

External tooth bleaching is associated with statistically significant short-term reductions in plaque and gingivitis indices. However, no data were available to evaluate long-term effects.

Stain control with two modified stannous fluoride/sodium tripolyphosphate toothpastes: A randomised controlled proof of concept study

OBJECTIVE

To compare build-up of extrinsic tooth stain following use of two novel anhydrous stannous fluoride/sodium tripolyphosphate (SnF₂/STP) toothpastes with adjusted (lower) relative dentin abrasivities (RDAs) versus a marketed control and a reference toothpaste.

METHODS

Following prophylaxis, 220 adults with extrinsic dental stain on anterior teeth facial surfaces were randomised to 4 weeks' twice-daily brushing with either novel 0.454% w/w SnF₂ (1100ppm fluoride)/5% w/w STP toothpastes with differing levels of abrasive silica: 'Test RDA∼58'; 'Test RDA∼77', or a reference: 'Ref RDA∼80' (1000ppm fluoride from sodium monofluorophosphate) or marketed control toothpaste: 'Ref RDA∼120' [0.454% w/w SnF₂ (1100ppm fluoride)/5% w/w STP]. Primary endpoint was total Macpherson modification of the Lobene Stain Index (MLSI) area×intensity (A×I) score at Week 4 for Test toothpastes versus Ref RDA∼80. Secondary endpoints were total MLSI (A×I) for all toothpastes versus Ref RDA∼120.

RESULTS

After 4 weeks, mean total MLSI scores for Test RDA∼58, Test RDA∼77 and Ref RDA∼80 were all lower than Ref RDA∼120. Ranking order of performance for controlling stain build-up was: Test RDA∼77 > Test RDA∼58 > Ref RDA∼80 > Ref RDA∼120. There was no statistical difference between Test RDA∼58 and Ref RDA∼80; Test RDA∼77 was statistically lower than RDA∼80. All toothpastes were generally well-tolerated.

CONCLUSION

This study showed low levels of stain build-up after 4 weeks' twice-daily use of novel, low abrasivity, anhydrous SnF₂ toothpaste formulations (RDA∼58, RDA∼77), similar to marketed toothpastes (RDA∼80; RDA∼120). Lowering the RDA of appropriately formulated SnF₂ toothpastes therefore may not negatively impact stain build-up potential (Clinicaltrials.gov NCT03160703).

CLINICAL SIGNIFICANCE STATEMENT

This study indicates lowering RDA of an anhydrous SnF₂ toothpaste does not appear to negatively impact its overall dental stain control potential. Development of appropriately formulated SnF₂ toothpastes with lower abrasivity may have additional benefits for individuals with dentin hypersensitivity by managing potential dentin wear.

Dental professionals' opinions and knowledge of smoking cessation and electronic cigarettes: a cross-sectional survey in the north of England

Aims

To determine the current level of knowledge and opinions of UK dental professionals with regards to smoking cessation and e-cigarettes.

Method

A self-administered online survey was distributed by postal invitation to all dental practices in the north of England registered on the National Health Service (NHS) Choices website.

Findings

One hundred and ninety completed questionnaires were received. Seventy-nine percent of respondents reported always enquiring about the smoking status of their patients with 17% completing referrals to a specialist stop smoking service. Just under half of respondents reported not receiving any smoking cessation advice training. Lack of time during appointments, lack of training and lack of perceived interest by patients were reported as the most important barriers. The importance of a lack of remuneration, as a barrier, varied considerably with professional role. Approximately a third (31%) of respondents were of the opinion that e-cigarettes are more or equally harmful than cigarettes with the majority not aware of any guidance documents or recommendations regarding e-cigarettes.

Conclusion

The majority of dental professionals in the north of England reported providing smoking cessation advice, although only half had training on this. Opinions on electronic cigarettes were mixed, with a third having negative views.

Assessing the effect of multibracket appliance treatment on tooth color by using electronic measurement

Background

The purpose of this study was to investigate how tooth color is affected by multibracket appliance (MBA) treatment.

Methods

The color of teeth #14 to #24 of 15 patients with MBA was measured on body and gingival tooth segments using the spectrophotometer Shade Inspector™. Colors of both segments were recorded before start of MBA treatment (baseline T₀), end of MBA treatment (T₁; 2 years ±0.3), and 3 months after T₁ (T₂). A 2D color system and a 3D system served as reference systems.

Multilevel models were used to analyze color change within segments and to compare the difference in color change between segments (treatment effect).

Results

2D system. Changes within tooth segments from T₀ to T₂ were at worst 2.0 units (ΔE in the gingival segment), which is less than the threshold of 2.7 units for a clinically meaningful difference. Confidence intervals for the treatment effect indicated no clinically important differences in color change between body and gingival segments.

3D system. Changes within tooth segments from T₀ to T₂ were at worst 2.3 units (ΔE in the body segment), which is less than the threshold of 2.7 units for a clinically meaningful difference. Confidence intervals for the treatment effect indicated no clinically important differences in color change between body and gingival segments.

Thus, MBA treatment did not lead to clinically relevant changes in tooth color.

Conclusion

Within the limitation of this study the MBA treatment can be seen as a safe method with respect to tooth color.

Correlation between alteration of enamel roughness and tooth color

Background

To establish the correlation between enamel roughness and color change of tooth.

Material and Methods

Enamel/dentin blocks (5 x 5 x 3.2 mm) were serially ground with the following abrasive paper: 1200-grit, 800-grit, and 600-grit SiC papers. In the paired model, the analyses of color (L*, a*, b*, ΔE) and roughness (Ra) were performed among the sandpaper exposure. The data were subjected to ANOVA using models for repeated measures followed by the Tukey test. The Pearson correlation test was used to determine whether there was a relationship between Ra values and color results (α = 0.05).

Results

The L* values decreased in accordance with the increase of Ra, with statistical difference between all the times (p<0.05). A correlation was found between the Ra vs. the L* values (r = -0.67; p<0.0001) and ∆Ra vs. ∆a* values (r = 0.29; p = 0.05); besides that, there was no significant correlation with b* values or significant alteration in the ∆E values (p>0.05).

Conclusions

The alteration of enamel roughness acted on the lightness and the green-red axis of tooth color. However, there was no significant correlation between the alteration of roughness of enamel and general color change of tooth.

Key words:Surface properties, tooth discoloration, color.

Color stability of a bis-acryl composite resin subjected to polishing, thermocycling, intercalated baths, and immersion in different beverages

OBJECTIVE

To evaluate the color of a bis-acryl resin after polishing, aging, and colorants.

MATERIALS AND METHODS

From the 140 disks obtained, 35 were not polished (NP), 35 were polished with 3-μm (3P), 35 with 3- and 1-μm (1P), and 35 with 3-, 1-, and 0.5-μm sized particles (05P). Five disks of each group were thermocycled for 20, 100, and 200 cycles. Sixty disks were thermocycled and kept in beverages (tea, wine, and coffee) after four cycles. Sixty disks were immersed in the beverages for 24 hours, a week, and a month. The coordinates L*a*b* were measured and the color differences were analyzed by ANOVA. The lightness, chroma, and hue differences were evaluated by repeated measures ANOVA. Comparisons were made with Tukey's test (α = 0.05).

RESULTS

Similar behaviors were observed between 3P and 05P groups (1.53 and 1.95ΔE₀₀ ) (P < .05). The NP group submitted to 200 cycles showed the biggest color differences (3.02) (P = .003). The greatest color differences were observed in the NP group submitted to immersion in coffee (8.30) and wine (7.93) (P < .05).

CONCLUSIONS

The polished surfaces were the least stained. Coffee and wine provided the greatest color changes, both for baths and immersions.

CLINICAL SIGNIFICANCE

Polishing of provisional surfaces restorations made of bis-acrylic resin is essential to minimize staining caused by aging and use of colorants, regardless of the particle size present in the polishing paste. The contact with coffee and red wine should be avoided, especially for clinical times greater than 1 week.

Bleaching of simulated stained-remineralized caries lesions in vitro

OBJECTIVE

Non-invasive esthetic treatment options for stained arrested caries lesions have not been explored. This study aimed to develop laboratory models to create stained-remineralized caries-like lesions (s-RCLs) and to test the efficacy of bleaching on their esthetic treatment.

MATERIALS AND METHODS

One hundred twelve enamel/dentin specimens were prepared from human molars, embedded, and had their color measured spectrophotometrically at baseline and after demineralization. They were randomly divided into four groups (n = 14) based on the staining/remineralization protocols for a total of 5 days: G1, no staining/no remineralization; G2, no staining/remineralization in artificial saliva (AS); G3, non-metallic staining/remineralization with sodium fluoride/AS; and G4, metallic staining/remineralization with silver diamine fluoride/AS. The lesion mineral loss (ΔZ) and depth (L) were measured using transverse microradiography along with color change (ΔE). Specimens were bleached and color was re-evaluated. Data were analyzed using ANOVA models followed by Fisher's PLSD tests (α = 0.05).

RESULTS

s-RCLs in G4 were significantly (p < 0.001) darker than G3, G2, and G1 regardless of substrate type and condition. s-RCLs in G2, G3, and G4 showed significantly lower ΔZ and L than G1 (all p < 0.001), confirming occurrence of remineralization. G4 exhibited significantly lower ΔZ and L compared to G2 (p < 0.001). Bleaching was more effective in non-metallic than in metallic stained lesions regardless of substrate type (p < 0.001).

CONCLUSION

The proposed models created distinct s-RCLs. Non-metallic s-RCLs were lighter and more responsive to bleaching compared to metallic s-RCLs.

CLINICAL RELEVANCE

The developed experimental models allow the further investigation of the efficacy and safety of different clinical strategies for the esthetic management of s-RCLs.

Investigation of the perceptual thresholds of tooth whiteness

OBJECTIVE

To investigate the tooth whiteness perceptibility thresholds of the average observer to changes in the CIELAB values and an optimised whiteness Index for dentistry (WIO) based on psychophysical studies.

METHODS

A psychophysical experiment based on visual assessments of digital images of teeth on a calibrated display with a group of observers (n=32) has been conducted to determine the perceptual thresholds in tooth whiteness. Digital simulations of a tooth that is identical in shape to the left incisor in the image of teeth were superimposed on to images. The colour of the simulated tooth was varied and observers were asked to respond whether there was a difference in whiteness between the left incisor and the simulated tooth. Thresholds for detection of differences in whiteness were independently determined in four conditions: ΔL*, Δa*, Δb* and a blue optical whitening direction. Raw data were fitted using a non-parametric approach and thresholds of CIELAB and WIO for each conditions were calculated.

RESULTS

Estimates of the threshold of the four conditions of ΔL*, Δa*, Δb* and a blue covarine optical tooth whitening direction were 1.14, 3.24, 1.11 and 1.51 respectively, with the corresponding WIO thresholds of 2.77, 6.52, 3.09 and 1.99 respectively.

CONCLUSIONS

The thresholds for tooth whiteness perception in CIELAB space and WIO space were determined. The findings demonstrate that for a whitening treatment with a blue covarine optical technology, a colour change of about 2 WIO units would be noticeable.

CLINICAL SIGNIFICANCE

This study gives a better understanding of the tooth whiteness perception threshold, and will help clinicians identify perceivable differences in tooth colour during matching and whitening procedures.

Effect of carbamide peroxide bleaching on enamel characteristics and susceptibility to further discoloration

STATEMENT OF PROBLEM

Whether tooth whitening alters the surface topography of enamel causing an increase in surface roughness that could increase susceptibility to restaining is unclear.

PURPOSE

The purpose of this in vitro study was to evaluate whether immersing enamel in common solutions produces a color change of ΔE greater than 2; whether the highest concentration carbamide peroxide bleaching agent produces the greatest ΔE; whether bleaching increases the susceptibility to further staining by common solutions; and whether morphologic changes to the enamel surface are observed after staining and bleaching as evidenced by scanning electron microscopy (SEM) analysis and energy-dispersive X-ray spectroscopy (EDS).

MATERIAL AND METHODS

Forty-five extracted human teeth were immersed in 5 solutions (wine, coffee, tea, soda, and water) for 15 days at 80°C, and the change in ΔE was assessed with a colorimeter. The teeth were bleached using different concentrations of carbamide peroxide (20%, 35%, and 44%) and ΔE was measured at different time intervals. The teeth were then restained with the same solutions. The ΔE after initial staining was compared with the ΔE after bleaching and restaining of the same teeth. SEM was performed at baseline, after staining, bleaching, and restaining to evaluate the changes in the enamel surface topography. EDS was used to determine the elemental composition of tooth surfaces after restaining.

RESULTS

All liquids caused a ΔE greater than 2 after 15 days. The concentration of bleaching agent was not significantly associated with ΔE for any stain types. No significant difference was found in the rate of staining between initial staining and restaining after bleaching. However, a significant effect of time was found for the staining, where the overall ΔE increased by 0.34 for each day in the solution (P<.001). SEM images showed no major changes to enamel topography after bleaching. However, a coating was noted on teeth stained with wine and tea, which had different elemental compositions when compared with the tooth surface.

CONCLUSIONS

Based on SEM observation, bleaching teeth with carbamide peroxide does not increase the susceptibility of enamel to staining and does not alter the topography of the enamel. Using higher bleaching concentrations did not increase tooth whitening as a function of time.

A Combined Approach for the Aesthetic Management of Stained Enamel Opacities: External Bleaching Followed by Resin Infiltration

Stained enamel opacities are frequently encountered in dental practice. However, due to the risk of unaesthetic outcome, managing such lesions by resin infiltration techniques alone is not advised. Therefore, performing external bleaching before resin infiltration procedure is mandatory to eliminate stains from the hypomineralized lesions in order to aesthetically infiltrate them. In this work, we describe clinical cases in which external bleaching and resin infiltration techniques were used for managing stained enamel hypomineralized lesions related to traumatic dental injuries and molar incisor hypomineralization. Despite the fact that this approach has some limitations, it could be concluded that external bleaching associated with the resin infiltration technique shows promising results to aesthetically manage stained enamel opacities when the stain is totally removed after bleaching.

Effect of Calcium-phosphate Desensitizers on Staining Susceptibility of Acid-eroded Enamel

OBJECTIVE

To investigate the effect of calcium-phosphate-based desensitizers, Teethmate AP paste (TMAP) and Teethmate Desensitizer (TMD) (Kuraray Noritake Dental, Tokyo, Japan), on the prevention of staining on acid-eroded enamel.

METHODS AND MATERIALS

Forty polished enamel samples (4×4×1 mm) from bovine incisors were randomly divided into five groups (n=8). After immersion in 50 mL of 0.5% citric acid (pH 2.5) for 15 minutes to form acid-eroded surfaces, the surfaces were subjected to different treatments with TMAP, TMD, and NaF (0.21% means 950 ppm) for five minutes. Another eroded group was not treated with desensitizer. For the control group, the samples were not eroded or treated. All the samples were stored in artificial saliva (AS) at pH 7.2 for 24 hours at 37°C. The TMAP, TMD, or NaF was reapplied at eight and 16 hours during the 24 hours of storage time. The surface roughness (Sa) was evaluated following ISO 25178 for surface texture using confocal laser scanning microscopy (VK-X 150 series, Keyence, Osaka, Japan) before acid erosion, after acid erosion, and after 24 hours of incubation in AS. Afterward, the color difference was measured with a dental colorimeter (Shade Eye NCC, Shofu, Kyoto, Japan) before and after staining with tea solution.

RESULTS

One-way repeated measures analysis of variance showed that acid erosion significantly increased Sa (p<0.001). TMAP- and TMD-treated groups exhibited lower Sa values than the NaF group and the no-desensitizer treatment group. The greatest staining was observed in the NaF group and the no-desensitizer group, while the TMAP and TMD groups significantly decreased the formation of stains.

CONCLUSIONS

Acid-eroded enamel increased surface roughness and tended to absorb more stains. However, the application of TMAP and TMD moderated the roughness and thus prevented the formation of extrinsic stains.

Clinical efficacy of a chlorhexidine-based mouthrinse containing hyaluronic acid and an antidiscoloration system in patients undergoing flap surgery: A triple-blind, parallel-arm, randomized controlled trial

OBJECTIVES

To evaluate the postsurgery gingival healing as well as plaque, gingival inflammation and staining levels following the use of a 0.2% chlorhexidine (CHX) solution with or without antidiscoloration system (ADS) and 0.2% hyaluronic acid (HA).

METHODS

Patients undergoing flap surgery at sites with an intact or reduced but healthy periodontium participated in a parallel-arm RCT. After surgery, patients used the assigned mouthrinse (CHX + HA + ADS or CHX) for 21 days. At days 7 and 21, the healing process was evaluated at experimental teeth using a composite index, namely the Gingival Healing Index (GHI). GHI score was obtained as the sum of the scores related to the severity of wound dehiscence (score 1-3) and the profile of the buccal and oral aspects of the papilla (score 1-3). Therefore, GHI ranged from 2 (worst quality of healing) to 6 (optimal quality of healing). Plaque Index (PlI), Gingival Index (GI), angulated bleeding score (AngBS), and tooth and tongue staining were also assessed.

RESULTS

In both groups, GHI assumed values of 5 or 6 at both days 7 and 21 in ≥50% of patients, and low median values of PlI, GI, AngBS and staining were observed during the 21-day period. Except for a significantly lower GI in CHX group at day 7, no other significant intergroup differences were found.

CONCLUSIONS

Postsurgery plaque control based on either CHX or CHX + HA + ADS mouthrinses results in optimal plaque control and quality of early gingival healing along with limited tooth and tongue staining.

Effect of tooth discolouration severity on the efficacy and colour stability of two different trayless at-home bleaching systems

Background. The use of trayless at-home bleaching agents in darker teeth is raising some concerns due to their unknown efficacy. The purpose of this in vitro study was to evaluate the effect of tooth discolouration severity on the efficacy and colour stability of two different trayless at-home bleaching systems.

Methods. Ninety enamel-dentin samples were divided into two groups: lighter tand darker teeth. The teeth in each group were further divided into three groups (n=15): (1) tray-based system with 10% carbamide peroxide (Opalescence Oh) (control group); (2) a tray applied whitening membrane with 10% hydrogen peroxide (Treswhite Supreme); and (3) a whitening pen with 22% carbamide peroxide (Hollywood Smiles). After bleaching, the teeth were stained for 9 days using red wine. Colour readings before bleaching treatment were determined using a dental spectrophotometer and were repeated 24 h after bleaching treatment and 24 h after staining process. Analysis of variance, Bonferroni and Dunnett C tests were used at 5% significance level.

Results. No differences were observed between the bleaching efficacy of Treswhite Supreme and Opalescence Oh in the lighter teeth, while Opalescence Oh had the best bleaching efficacy in the darker teeth (p<0.05). Hollywood Smiles had the worst bleaching efficay but the best color stability in both lighter and darker teeth (p<0.05). No differences were observed between the color stability values of Treswhite Supreme and Opalescence Oh.

Conclusion. This study suggested that both the tooth discolouration severity and the type of trayless system used affected the bleaching efficacy, whereas only the type of trayless system affected the color stability.

Complications From Surgically Assisted Rapid Maxillary Expansion With HAAS and HYRAX Expanders

The current study aimed at comparing the number and type of undesired outcomes during and after the maxillary expansion performed with HYRAX and HAAS expanders. A total of 90 patients (41 males and 49 females, 45.6% and 54.4%, respectively) aged 18 to 59 (mean age of 26.1; standard deviation [SD] = 7.4) underwent subtotal Le Fort I osteotomy and pterygomaxillary disjunction following surgically assisted rapid maxillary expansion (SARME) carried out using HAAS (n = 29; 48.3% male and 51.7% female; mean age = 27: SD = 7.7) and HYRAX (n = 61; 44.3% male and 55.7% female; mean age = 26; SD = 7.2) expanders. Post-SARME dento-gingival, radiographic, and clinical undesired outcomes were evaluated. A total of 16 (17.8%) patients experienced at least 1 undesired outcome-7 (7.8%) and 9 (10.0%) in HAAS and HYRAX group, respectively. The most common undesired outcomes were radiographic asymmetric expansion-2 (2.2%) and 3 (3.3%) in HAAS and HYRAX group, respectively-followed by pain during out-of-clinic expansion 4 (4.4%) in HAAS group only-dental darkening 5 (5.5%) in HYRAX group, only, requiring root canal treatment, and local infection-2 (2.2%), 1 in each HAAS and HYRAX groups. Excepting for complications arising from the acrylic stop plate in HAAS expander, the number and severity of complications observed in the current study did not differ due to the use of HAAS and HYRAX appliances to perform maxillary expansion. Hygiene issues do not rule out the use of HAAS. The wider maxillary expansion performed, the more frequent are the cases of asymmetric expansion.

Effect of sodium fluoride pretreatment on the efficacy of an in-office bleaching agent: An in vitro study

This in vitro study evaluated the effect of sodium fluoride (NaF) on the bleaching efficacy using an artificial discolored bovine tooth model. Twenty specimens were prepared from bovine teeth by staining with black tea extract and were divided into two groups (n = 10). In control group, specimens were immersed in distilled water for 30 min. In NaF group, specimens were applied with 0.2% NaF for 30 min. Then, the specimens in each group were bleached by an in-office bleaching material (Shofu Hi-Lite, Shofu, Kyoto, Japan). The CIE L*a*b* values were measured by a dental colorimeter before and after 10 consecutive bleaching treatments, and the color difference (ΔE) was calculated. Brightness and color difference (ΔE) increased in both groups per bleaching cycle. There were no statistical differences in ΔE values between both groups (p > 0.05). It was concluded that the application of NaF before bleaching did not interfere with the bleaching effect.

Hydrogen Peroxide Might Bleach Natural Dentin by Oxidizing Phosphoprotein

Recent studies suggested that bleaching agents may whiten teeth by oxidizing the fluorescent materials, which are the proteins located in the organic-inorganic interface. Therefore, we postulated that fluorescence of dentin came from dentin phosphoprotein (DPP) and that bleaching agents might bleach dentin by oxidizing DPP. Fifty-six specimens were randomly divided into 4 groups and exposed to distilled water, hydrogen peroxide (HP), ethylenediamine tetraacetic acid disodium salt (EDTA), and acetic acid for 24 h. After measuring the organic and inorganic components, fluorescence, and color characteristics of dentin before and after exposure, we found that when DPP was removed from dentin by EDTA, fluorescent intensity declined proportionally with the reduction in Raman relative intensity, and dentin was whitened considerably, with an Δ E value 6 times higher than that of the distilled water group. On the contrary, due to the incapability of acetic acid to dissolve DPP during decalcification, fluorescent intensity values and tooth color remained nearly unchanged after exposure to acetic acid. Dentin exposed to neutral HP showed no obvious morphologic and organic/inorganic component changes except for the destruction of DPP. Similarly, dramatically decreased fluorescent intensity and lightened color were found in the HP group. Moreover, DPP solution of the HP group exhibited decreased ultraviolet absorbance, especially between 250 and 300 nm, which arose from aromatic amino acids. The results indicated that DPP was responsible for the fluorescent properties of dentin and that HP might bleach dentin by the oxidization of aromatic amino acids in DPP. These findings are of great significance in promoting our further understanding of the mechanism of tooth bleaching and the fluorescent property of normal dentin.

Real-time binding kinetic analyses of the interaction of the dietary stain orange II with dentin matrix

OBJECTIVES

Dietary stains can be adsorbed into the dentin of teeth. Using Orange II as a model dietary stain, this study investigated the strength of its interaction with the mineral and protein components of dentin matrix and how hydrogen peroxide (H₂O₂) treatment influences this interaction.

METHODS

Dentin slices were prepared from human teeth and were either deproteinized (5.6% sodium hypochlorite, 12 days), demineralised (0.5 M EDTA, 3 days) or left as intact control samples. Samples were stained with Orange II for 1-168 h, during which staining intensity was quantified by image analysis. Similarly, uptake of stain by deproteinized / demineralized samples treated with 10 or 30% H₂O₂ was investigated. Using surface plasmon resonance technology, real-time binding kinetics were determined assessing the interaction of Orange II with the dentin matrix protein constituents, collagen type I, biglycan, decorin, dentin sialoprotein and osteopontin.

RESULTS

Deproteinization of dentin matrix reduced the uptake of the Orange II compared to the intact control. Conversely, demineralization of dentin samples increased the uptake of the dye. Treatment of samples for 48 h with H₂O₂ reduced subsequent uptake of the Orange II. Real-time kinetic analysis indicated moderate strength of binding for Orange II with collagen type I, weak binding with decorin and biglycan and negligible binding with dentine sialoprotein and osteopontin.

CONCLUSION

These results indicate a predominant role for collagen type I, which accounts for 90% of the organic protein matrix of teeth, for attracting dietary stains. Binding analyses indicate that the interaction is highly dissociable, and further binding is reduced following H₂O₂ treatment.

CLINICAL SIGNIFICANCE

This study provides new information regarding adsorption of dietary stains into tooth dentin, suggesting that they are attracted and moderately bound to the collagen type I matrix. This study also contributes valuable information for discussion for considering the effect of H₂O₂ on bleaching teeth and its influence on subsequent uptake of dietary stains following whitening treatments.

Management of intrinsic discoloration using walking bleach technique in maxillary central incisors

Introduction

Non-vital bleaching is a non-invasive technique to treat the intrinsic discoloration of teeth of several etiologies. Hydrogen peroxide and sodium perborate are commonly used bleaching agents.

Aim

The aim of this case report is to demonstrate the non-vital bleaching technique in maxillary anterior teeth.

Method

Maxillary central incisors were isolated with rubber dam and root canal treatment was performed. Barrier space preparation was done using a heated instrument. Glass ionomer cement was used a barrier material. Mixture of hydrogen peroxide and sodium perborate was placed in the canal and sealed with intermediate restorative material. After 1 week, the procedure was repeated to achieve the desired results.

Conclusion

Non-vital bleaching is a minimally invasive procedure to restore the esthetics of a discolored non-vital tooth. However, care should be taken to prevent any post-operative complications.

Replicating a discolored tooth preparation: A technique for effective laboratory communication

Fabricating a ceramic restoration for a discolored anterior tooth presents a clinical challenge. The dental technician is often hampered by being unaware of the shade of the discolored tooth preparation, which influences the color of the overlying ceramic restoration. A definitive cast that replicates the shade of the prepared tooth helps the ceramist to fabricate a restoration that masks the discoloration appropriately and still achieves the desired optical properties. This report demonstrates the use of a technique of recording and communicating the shade of a prepared tooth to the dental laboratory technician.

Randomized clinical study of alterations in the color and surface roughness of dental enamel brushed with whitening toothpaste

OBJECTIVES

This clinical study evaluated the influence of whitening toothpaste on color and surface roughness of dental enamel.

MATERIALS AND METHODS

Initially, the abrasiveness of the toothpastes used (Sorriso Dentes Brancos [SDB]; Colgate Luminous White and Close up White Now) was tested on 30 (n = 10) plexiglass acrylic plates that were submitted to mechanical tooth brushing totalizing 29,200 cycles. Subsequently, 30 participants were selected, and received a toothbrush and nonwhitening toothpaste (SDB). The participants used these products for 7 days and initial color readouts (Spectrophotometer) and surface roughness of one maxillary central incisors was performed after this period of time. For surface roughness readouts, one replica of the maxillary central incisor was obtained by a polyvinyl siloxane impression material (Express) and polyurethane resin. After baseline measurements, participants were separated into three groups (n = 10), according to the toothpaste used. The participants returned after 7, 30, and 90 days when new color readouts and surface roughness were recorded. The measured values were statistically analyzed (2-way-ANOVA, repeated measures, Tukey, P < .05).

RESULTS

Whitening toothpastes did not promote significant (P > .05) color alteration and nor increased the surface roughness of the dental enamel in brushing time of the study.

CONCLUSIONS

The abrasiveness of whitening toothpaste and the brushing trial period did not affect the surface roughness of dental enamel. However, color changes observed on enamel were above the perceptibility and acceptability thresholds reported in the literature.

CLINICAL SIGNIFICANCE

The over-the-counter toothpastes tested had an effect on dental enamel color above the perceptibility and acceptability thresholds but did not change the surface roughness of the teeth.

Does orthodontic treatment have a permanent effect on tooth color? : A systematic review and meta-analysis

OBJECTIVES

Aim of this systematic review was to assess the effect of orthodontic treatment with fixed appliances on the tooth color of patients.

METHODS

Nine databases were searched up to May 2017 for clinical cohort studies on the effect of fixed appliance treatment on tooth color. After elimination of duplicate studies, data extraction, and risk of bias assessment according to the Cochrane guidelines, random effects meta-analyses of mean differences (MD) or means and their 95% confidence intervals (CIs) were performed, followed by GRADE (Grading of Recommendations Assessment, Development and Evaluation) assessment of the quality of evidence.

RESULTS

Three nonrandomized and one randomized study with a total of 138 patients (46% male, 54% female) with average age of 15.7 years were included. Tooth color of treated patients was significantly altered during or after orthodontic treatment (4 studies; average of 3.2 ∆E units; 95% CI = 2.0-4.4 ∆E units), which was more than the variation among controls (1 study; MD = 1.9 ∆E units; 95% CI = 1.7-2.2 ∆E units). However, the quality of evidence was very low, due to the inclusion of nonrandomized studies, bias, and imprecision. Re-analysis of raw study data indicated that significant differences in clinically discernable treatment-induced color changes were seen between chemically and light-cured adhesives and among the various tooth categories.

CONCLUSION

Existing evidence of very low quality indicates that orthodontic treatment might be associated with alterations of tooth color, which are however not consistently clinically discernible. Treatment-induced color alterations might be dependent on bonding material and tooth type, but evidence supporting this is weak.

A randomized clinical trial to evaluate the stain removal efficacy of a sodium phytate dentifrice formulation

Objectives

Phytate is an organic, cyclic polyphosphate analogous to linear condensed polyphosphates used as stain removal agents. This study investigated stain removal efficacy of an experimental sodium phytate‐containing dentifrice compared to a reference dentifrice.

Methods

An experimental, moderate abrasivity (relative dentine abrasivity [RDA] ∼130) antisensitivity fluoride dentifrice containing sodium phytate (0.85% w/w as the hexasodium salt) (n = 111) was compared to a reference, marketed, low‐abrasivity (RDA ∼ 43), anti‐sensitivity fluoride dentifrice (n = 113), both containing 1150 ppm fluoride as sodium fluoride. Primary efficacy variables were between‐treatment differences in extrinsic dental stain of anterior teeth after 6 and 12 weeks' twice‐daily use, using Lobene stain index (MacPherson modification, MLSI) mean area (A) and intensity (I) scores. Comparisons included whole‐tooth and hard‐to‐reach areas (gingival, interproximal, body of lingual).

Results

At both 6‐ and 12‐week timepoints, MLSI (A × I) scores for total area and hard‐to‐reach areas for the experimental dentifrice were statistically significantly lower than baseline (P < .0001 for all). This was demonstrated for the reference dentifrice at 6 weeks only, for total, interproximal (P < .0001 for both), and body of lingual (P = .0395) scores. Compared with the reference, the experimental dentifrice had statistically significantly lower MLSI scores at both 6 and 12 weeks for all outcome variables including both total MLSI (A × I) and hard‐to reach areas (P < .0001 in all cases). Products were generally well‐tolerated.

Conclusions

Differences between treatments were considered clinically differentiable. Sodium phytate may therefore be a suitable additive ingredient to improve tooth stain control performance within an otherwise conventional dentifrice formulation.

Clinical Significance

Following 6 and 12 weeks brushing, clinically differentiable differences were shown in stain index scores with an experimental dentifrice containing sodium phytate compared to a reference dentifrice without sodium phytate. Sodium phytate may therefore be a suitable additive ingredient to improve tooth stain control performance within an otherwise conventional dentifrice formulation.

Effect of pH on whitening efficacy of 35% hydrogen peroxide and enamel microhardness

OBJECTIVE

This study aimed to evaluate the effect of 35% hydrogen peroxide at different pH values and the degree of tooth staining on whitening efficacy and enamel microhardness.

MATERIALS AND METHODS

90 enamel-dentin specimens were obtained from bovine incisors. They were randomly divided into 2 groups (n = 45), 1 group was immersed in a staining broth for 14 days, and another group was not stained and kept in distilled water at 37°C. Twenty-four hours after the staining procedure, each group was distributed into 3 subgroups that were whitened by 35% hydrogen peroxide with different pH values (5, 7, and 8.4) for 30 minutes. The color was measured at baseline and 7 days after whitening. Microhardness was measured at baseline, immediate, 24 hours, and 1 month after the whitening procedure. Data were submitted to 2-way analysis of variance (ANOVA) and the Tukey test for multiple comparisons for color analysis. Repeated measures ANOVA and the Tukey test were used to analyze microhardness data.

RESULTS

The color change of the stained groups (ΔE₀₀  = 4.6) was significantly higher than that of the nonstained groups (ΔE₀₀  = 3.7). Microhardness value decreased significantly immediately after whitening for all subgroups and did not return to initial values. For each measurement time, microhardness was not significantly different among subgroups with different pH values.

CONCLUSIONS

Despite the effectiveness of 35% hydrogen peroxide, changes on gel pH did not affect the whitening efficacy, and the enamel was superficially demineralized, regardless of pH values.

CLINICAL SIGNIFICANCE

Independently of the pH value of whitening gel, enamel undergoes superficial demineralization and with a reduction in superficial microhardness that does not return to the initial values. However, using hydrogen peroxide with different pH values does not alter the whitening effect.

The in vitro and in vivo reproducibility of a video-based digital imaging system for tooth colour measurement

OBJECTIVES

To assess the robustness of a new custom built video-based digital imaging system (VDIS) for measuring tooth colour and whiteness under in vitro and in vivo conditions.

METHODS

The VDIS imaging system was developed for tooth colour measurement and evaluated in vitro and in vivo. The in vitro validation used extracted human teeth (HT, n=14) stored in water and VITA Classical shade guide tabs (SG, n=16). These were measured by the VDIS at baseline, 5min, 2h, 1 week and 2 weeks to evaluate the system repeatability. For in vivo validation, adult volunteers (male/female, n=34) with two natural, unrestored central incisors had their teeth imaged using the VDIS at baseline, 5min and 2h (3 images each) by two different operators to evaluate time and operator effects. Between taking individual images, subjects moved from the imaging-frame to assess the effect of re-positioning on reproducibility. From the in vitro and in vivo images, the average tooth RGB values were obtained, and the CIELAB values and a tooth whiteness index WIO value were calculated. Repeatability and reproducibility of VDIS imaging system was assessed using appropriate repeated measurement analysis techniques and ANOVA.

RESULTS

The measurement variations in vitro were between 1 and 2 units of ΔWIO and the average colour differences were less than 1 ΔE^*_ab unit. For the in vivo study, analysis of the CIELAB parameters and WIO showed that subject variability accounted for between 82 and 99% of the observed variability in the measurement process. The operator variability was less than 0.5% and the overall measurement error was found to be only 0.3% for WIO. Across assessment times the variability was less than 0.5%.

CONCLUSIONS

The dental imaging system V-DIS was shown to be a highly reproducible means for tooth colour and whiteness measurement.

CLINICAL SIGNIFICANCE

Digital imaging based techniques gives a highly reproducible approach to measuring tooth colour.

Color stability of CAD/CAM Zirconia ceramics following exposure to acidic and staining drinks

Background

The aim of this in vitro study was to evaluate the color stability of CAD/CAM Zirconia ceramics following exposure to acidic drink (Coca Cola) and after exposure to staining solution (coffee).

Material and Methods

All the samples were immersed in different staining solutions over a 28-day test period. A colorimetric evaluation according to the CIE L*a*b* system was performed by a blind trained operator at 7, 14, 21, 28 days of the staining process. Shapiro Wilk test and Kruskal-Wallis ANOVA were applied to assess significant differences among restorative materials. Paired t-test was applied to test which CIE L*a*b* parameters significantly changed after immersion in staining solutions.

Results

One week immersion in acidic drink did not cause a perceivable discoloration for all restorative materials (ΔE < 3.3). Subsequent immersion in coffee affected color stability of all Zirconia samples, even if Kruskal-Wallis ANOVA found significant differences among the various restorative materials.

Conclusions

The ∆Es of CAD/CAM Zirconia ceramics after immersion in coffee varied among the products, but color integrity is not affected by contact with acidic drinks.

Key words:CAD/CAM restorative materials, CIE Lab, Zirconia ceramics.

Differences of Tooth Colorimetric Parameters L*a*b* Depended on Age

AIM:

The study aimed to analyse differences in colourimetric parameters L*a*b*, depended on age.

MATERIAL AND METHODS:

In this study were included 255 subjects with age interval from 20 to 49 years. The subjects were divided into three groups, as follows: in the younger group were 20 to 29 years of age, those in the middle group 30 to 39 years and older group 40 to 49 years. The overall number of analysed teeth in the intercanine sector of the maxilla was 2295. The colour of the teeth was measured using the spectrophotometer VITA Easyshade.

RESULTS:

The results for differences in the colourimetric parameters in relation with age were tested with Pearson Chi-square (χ²). For χ² = 572, 87 and df = 124 there was a statistical significant difference between the ages P < 0.001.

CONCLUSION:

In this study, it was concluded that the parameter L* - Lightness was decreasing when age increased. In the age group, 20 to 29 years L* was 83.2, whereas in the older group of this investigation; 40 to 49 years was 79.4. In the youngest group, the parameter a* was - 0.7, whereas with increasing of age this parameter was -0.5. The values for parameter b* from the youngest to the older group were from 21.7 to 23.9.

Tooth colour and whiteness: A review

OBJECTIVES

To review current knowledge concerning the application of colour science on tooth colour and whiteness description, measurement, distribution and its psychological impact.

DATA SOURCES

"Scopus" databases were searched electronically with the principal keywords tooth, teeth, colour, white, whiteness. Language was restricted to English and original studies and reviews were included. Conference papers and abstracts were excluded.

CONCLUSIONS

The appearance and colour of teeth are a common concern for patients across many populations and are associated with an increased desire for treatments that improve dental aesthetics, including tooth whitening. The application of colour science in dentistry has allowed the precise description of tooth colour and whiteness. Coupled with the advances in instrumental tooth colour measurement, such as spectrophotometers, colorimeters, spectroradiometers and digital imaging systems, these parameters are quantifiable in a reproducible and robust manner. These principles have been applied to the tooth colour distribution in many study populations, indicating, in general, differences in tooth colour for subject age and gender, but not for ethnicity. Psychophysical studies on tooth colour and whiteness via third party assessment of images indicate that whitened teeth lead to judgements that are more positive on personality traits such as social competence and appeal, intellectual ability and relationship satisfaction.

In vitro evaluation of a silica whitening toothpaste containing blue covarine on the colour of teeth containing anterior restoration materials

OBJECTIVES

To investigate the effects of a silica-based whitening toothpaste containing blue covarine on the colour of restorations in extracted human teeth.

METHODS

Human extracted teeth were mounted in acrylic resin. A cavity was cut into the enamel surface and the specimen restored with either glass ionomer or composite dental materials. Following 4 weeks storage in water, specimens were treated with either water, red wine or a toothpaste containing blue covarine (n=10) for 24h followed by brushing with a silica-based toothpaste. Specimens were imaged with a digital imaging system at baseline, after 24h treatment and after brushing with a silica-based toothpaste. CIELAB colour parameters were determined for the restoration and the whole specimen and overall mean colour changes calculated (ΔE). Baseline and post-brushing images were compared subjectively for overall stain and staining around the restoration margin.

RESULTS

Red wine produced the largest ΔE values for whole specimens and for all restoration materials and the largest subjective stain scores for whole specimens and restoration margins. The red wine stain was not completely removed by brushing with a silica-based toothpaste. Comparisons of the red wine group with either the blue covarine toothpaste group or the water group were of statistical significance for all parameters (ANOVA, Tukey-Kramer, p<0.05). Following brushing with the silica-based toothpaste, specimens from the blue covarine toothpaste group were not significantly different (p>0.05) to the water group, for all restoration material types.

CONCLUSIONS

Exaggerated treatment with a blue covarine containing toothpaste does not significantly affect the colour of the restoration or the restoration margin of the dental materials tested versus a water alone treatment.

CLINICAL SIGNIFICANCE

The silica-based blue covarine containing toothpaste does not permanently stain the restorative materials tested or their margins.

Whitening-dependent changes of fluorescence of extracted human teeth

OBJECTIVE

To evaluate in vitro the fluorescence properties of extracted human teeth whitened with 40% hydrogen peroxide.

MATERIALS AND METHODS

A total of 28 extracted human teeth were pumiced for 1 minute using a low-speed dental handpiece and a disposable rubber cup. Pre-whitening fluorescence measurements (T0), maximum excitation (Ex_max ), maximum emission (Em_max ), and maximum intensity (I_max 10⁸ ), were performed using a spectrofluorometer. After T0 measurements, the teeth were whitened using the in-office method with 40% hydrogen peroxide, three times for 20 minutes. The fluorescence parameters were measured under the same conditions 7 and 14 days after bleaching (T1 and T2, respectively).

RESULTS

Ex_max exhibited a broader range 7 days after whitening and decreased after 14 days. The Em_max and I_max 10⁸ displayed a narrower range after whitening. The mean Ex_max differed significantly between the time points (F = 20.09. P < .001). The corresponding analysis for the mean Em_max differed significantly between the time points (F = 16.69, P < .001). The same was true for the mean I_max 10⁸ (F = 9.69, P < .001).

CONCLUSIONS

Within the limitations of this study, whitening provoked statistically significant changes in fluorescence of the intact teeth in vitro.

CLINICAL SIGNIFICANCE

The appearance of human teeth and dental materials and their changes upon aging and exposure to different agents (staining, whitening) is a topic of great relevance to esthetic dentistry. While some appearance parameters, such as color, translucency, and gloss, have been thoroughly studied, fluorescence and its influence on overall tooth appearance is still not well understood, yet it has influenced the development of fluorescence emitting restorative materials.

Comparative Evaluation of Antiplaque Efficacy between Essential Oils with Alcohol-Based and Chlorhexidine with Nonalcohol-Based Mouthrinses

Aim and Objectives:

The aim of this study is to compare the antiplaque efficacy of alcohol-based mouthwash with essential oils and nonalcohol-based chlorhexidine mouthrinse in 4 days plaque re-formation study.

Materials and Methods:

The current research paper is double-blinded, parallel designed clinical trial that was conducted in the Department of Periodontics and Oral Implantology, Kalinga Institute of Dental Sciences, Bhubaneswar. This included ninety dental students of Bachelor of Dental Surgery curriculum (in the age range from 20 to 24 years) Professional cleaning with scaling and polishing was carried out to acquire a zero plaque and gingival index (GI) for all ninety patients at baseline. Ninety patients were randomly divided into three groups with thirty patients in each group named as Group A, B, and C, respectively. Two commercially available mouthrinses, one containing alcohol (labeled as Solution (A) and one without alcohol (labeled as Solution (B) were placed in identical bottles and distributed to Group A and Group B patients. Whereas, the Group C patientswere instructed to use warm saline mouth rinse. The statistical analysis was performed using the Statistical Package for the Social Sciences software (Version 18).

Results:

Essential oils with an alcohol-based and chlorhexidine (CHX) alcohol-free mouthrinse (0.2%) groups compared to normal saline showed significant reductions in GI and PI scores.(P < 0.0001).

Conclusion:

The antiplaque efficacy of both alcohol-based mouthwash with essential oils and nonalcohol based CHX mouthwash were found to be equally effective in 4 days of plaque re-formation.

Evaluation of the effect of different enamel surface treatments and waiting times on the staining prevention after bleaching

Background

Bleached dental enamel can be more susceptible to staining than the enamel that has never been bleached, especially right after tooth bleaching. The aim of this study is to evaluate the effect of surface treatments and waiting time prior to contact with dye on bleached enamel staining susceptibility.

Material and Methods

One hundred teeth were bleached with 35% hydrogen peroxide (Whiteness HP, FGM) and randomly assigned to G1 artificial saliva, G2 2% sodium fluoride (Flugel, Nova DFL), G3 casein phosphopeptide-amorphous calcium phosphate fluoride paste (CPP-ACPF, MI Paste Plus, GC America), G4 rinse for color maintenance after bleaching (Keep White Rinse, DMC) and G5 polishing with aluminum oxide-impregnated disks (Super Buff Disk, Shofu). Fifty specimens were immersed in red wine for 15 minutes, immediately after treatment, and the others one hour after. Color difference (∆E) was evaluated with a spectrophotometer (Vita EasyShade). Surface treatments and waiting time effects were analyzed with Kruskal-Wallis and Mann Whitney tests (p<0.05).

Results

Surface treatments (p>0.05) and waiting time (p>0.05) were not significant to decrease bleached enamel susceptibility to red wine staining.

Conclusions

Surface treatments were similar to artificial saliva for bleached enamel susceptibility to red wine staining. Immediate or one-hour-postponed contact with red wine did not affect bleached enamel color.

Key words:Tooth bleaching, color, dental enamel, hydrogen peroxide, pigmentation.

Decreased dentin tubules density and reduced thickness of peritubular dentin in hyperbilirubinemia-related green teeth

Background

It is stated anecdotally that patients with liver diseases in childhood who develop green teeth have increased risk for rampant caries, which may be secondary to changes in dental structure. The aim of this study was to test the hypothesis that hyperbilirubinemia affects the dentin morphology of green teeth.

Material and Methods

Sixteen primary teeth were prepared and divided into two groups (green teeth, n = 8 and control, n = 8), which were transversely fractured across the cervical third of the dental crowns; dentin was prepared and sputter-coated with gold, and examined under a scanning electron microscope. The mean density and mean diameter of dentin tubules, as well as the thickness of peritubular dentin, were compared.

Results

Hyperbilirubinemia was associated with a decrease in the density of the dentin tubules (p< .01) and the thickness of peritubular dentin of green teeth (p< .01).

Conclusions

There was a correlation between childhood hyperbilirubinemia and changes in the dentin morphology, including a decrease in the density of the dentin tubules and a reduction in the thickness of peritubular dentin in green teeth.

Key words:Hyperbilirubinemia, liver disease, childhood, dentin tubules, human teeth, scanning electron microscopy.