Activated charcoal toothpastes do not increase erosive tooth wear

Surface roughness and stainability of CAD-CAM denture base materials after simulated brushing and coffee thermocycling

STATEMENT OF PROBLEM

Denture bases machined from prepolymerized materials have become popular. However, information on the effect of simulated brushing and coffee thermocycling (CTC) on their surface roughness and stainability is lacking.

PURPOSE

The purpose of this in vitro study was to compare the effect of simulated brushing and CTC on the surface roughness (Ra) and stainability of computer-aided design and computer-aided manufacturing (CAD-CAM) denture base materials and a heat-polymerized denture base material.

MATERIAL AND METHODS

Forty disk-shaped specimens were prepared from 3 CAD-CAM denture base resins (AvaDent, AV; Merz M-PM, M-PM; and Polident d.o.o, Poli) and a heat-polymerized polymethylmethacrylate resin (Promolux, CV) (n=10). Ra values of the specimens were measured by using a noncontact profilometer after conventional polishing. The color coordinates were also measured over a gray background with a spectrophotometer. Specimens were then consecutively subjected to simulated brushing for 20 000 cycles, CTC for 5000 cycles, and another 10 000 brushing cycles. Ra and color coordinates were measured after each interval. Color differences (ΔE00) were calculated by using the CIEDE2000 formula, and the data were analyzed by using 2-way analysis of variance and Tukey honestly significant difference tests (α=0.05).

RESULTS

The time interval had a significant effect on Ra (P<.001) as brushing cycles resulted in higher values than those at baseline and after CTC (P<.001). However, the differences between brushing cycles (P=.143) and between the baseline and after CTC (P=.994) were not significant. The interaction between the material type and time interval was significant for ΔE00 (P=.016). The only significant difference in ΔE00 values was observed between M-PM and CV after all treatments were completed (P=.029).

CONCLUSIONS

Brushing increased the Ra of all materials when compared with the baseline. All materials showed similar stainability throughout the brushing and CTC processes. However, M-PM CAD-CAM denture base resin underwent a greater color change after all treatments were completed than conventional denture base resin. All color changes can be considered clinically small, considering reported perceptibility and acceptability thresholds.

Characteristics of tin-containing fluoride toothpastes related to erosive tooth wear protection

OBJECTIVES

To assess the effect of different tin-containing toothpastes on the control of erosive tooth wear in enamel and dentin.

METHODS

Enamel and dentin slabs were randomly distributed into 7 experimental groups (n = 10/substrate): C-: negative control (Artificial saliva); AmF (regular fluoridated toothpaste without tin); Sn-1 (SnF2/NaF); Sn-2 (SnF2/NaF/SnCl2); Sn-3 (SnCl2/NaF); Sn-4 (SnF2/SnCl2); Sn-5 (SnCl2/AmF/NaF/chitosan). Specimens were submitted to 5-day erosion-abrasion cycling. Surface loss (SL) was determined with an optical profilometer. Tin deposition on the tooth surfaces and some characteristics of the toothpastes (pH, potentially available F-, %weight of solid particles, and RDA) were also assessed. Data were statistically analyzed (α = 0.05).

RESULTS

For enamel, the Sn-2 presented the lowest SL, not differing significantly from AmF, C+, and Sn-3. The SL of these groups was significantly lower than the C-, except for Sn-3. Sn-1 and Sn-4 were also not significantly different from C-. For dentin, C- significantly showed the highest SL values, whilst, Sn-1 presented the lowest SL, not differing significantly from AmF, Sn-2, C+, and Sn-3. There was a significant positive association between enamel SL and the pH and tin deposition. Dentin SL was significantly negatively associated with the %weight of solid particles and RDA.

CONCLUSIONS

Most of the tin-toothpastes were able to exhibit some protection against ETW. In this process, the toothpastes characteristics play a role, as lower enamel SL was significantly associated with lower pH values and tin deposition; and lower dentin SL was associated with higher %weight of solid particles and RDA of the toothpastes.

CLINICAL SIGNIFICANCE

Tin-containing toothpastes can be used for erosive tooth wear protection, but our study showed that their effect depends on the pH, amount of tin deposition, % weight of solid particles and RDA of the toohpastes.

Is the whitening effect of charcoal-based dentifrices related to their abrasive potential or the ability of charcoal to adsorb dyes?

OBJECTIVES

To evaluate if tooth color alteration of activated charcoal-based dentifrices may be attributed to the dye adsorption potential of charcoal (chemical action - C - slurry only) or to the association of dye adsorption with abrasion (chemo-mechanical action - CM- slurry/toothbrushing). Potential adverse effects in surface roughness, gloss, and wear were also assessed.

METHODS

Bovine enamel/dentin specimens were randomly allocated into the groups according to treatments and test model (n = 15): deionized water (negative control- NC); Colgate Maximum Anticaries Protection (conventional toothpaste- positive control- PC); Colgate Luminous White Activated Charcoal (LW); Oral-B 3D White Therapy Charcoal (WT); Curaprox Black is White (BW); Dermavita Whitemax (Activated charcoal powder- WP). Specimens were exposed to the C or CM models, in 28-day staining-treatment cycling. Color change (ΔE00), whiteness index (ΔWID), percentage of alteration of surface roughness (%Raalt), and gloss (%GUalt) were calculated. Additional specimens (n = 9) were indented with a Knoop diamond and subjected to 100,000 abrasion cycles. Enamel wear was determined by calculating the decrease in indentations geometry. Data were analyzed by ANOVA/Tukey tests (α = 0.05).

RESULTS

The CM-model produced lower color change (staining) than C (p = 0.0001). PC, LW, WT, BW, and WP showed similar color results for both models, differing from NC (p < 0.05).%Ra and%GU did not differ among the C-model groups (p > 0.05) and WP exhibited the highest variation (%Ra and%GU) under CM-model. Enamel wear values were lowest in the NC and PC groups, intermediate for LW, WT, BW, and highest for the WP (p < 0.05).

CONCLUSION

Activated charcoal-based dentifrices have a similar ability to minimize tooth staining as the conventional toothpaste, with increased enamel wear potential in the long term (after 100,000 cycles). The activated charcoal powder damaged the enamel surface, showing a higher deleterious effect on enamel roughness, gloss, and wear.

CLINICAL SIGNIFICANCE

Dentifrices containing activated charcoal do not provide superior results to minimize tooth staining compared to conventional toothpaste. Charcoal powder should be used with caution because it promotes higher superficial alterations on the enamel surface.

Effect of whitening toothpastes and activated charcoal powder on enamel wear and surface roughness

This study aimed to evaluate surface roughness (Sa), roughness profile (Rv), and enamel wear after brushing with different whitening toothpastes and charcoal powders. Sixty (n = 10) bovine enamel blocks (6 × 6 × 3 mm) were randomly distributed into six groups according to toothpaste type: regular toothpaste (CONT), toothpaste containing 2% hydrogen peroxide (HP), toothpaste containing titanium dioxide (TiO2), toothpaste containing charcoal (COAL), toothpaste containing charcoal and TiO2 (COAL+TiO2), and activated charcoal powder (COAL_PWD). Each block was subjected to 30,000 reciprocal cycles at a 1:3 proportion slurry. After brushing, the blocks were analyzed using an optical profilometer to determine Sa, Rv, and enamel wear. In addition, representative 3D images of each group and wear profiles were obtained. Sa was analyzed using generalized linear models followed by Bonferroni correction, whereas Rv was analyzed using one-way analysis of variance. After brushing, COAL and COAL+TiO2 showed higher Sa values than COAL_PWD. However, no significant difference was observed in Sa between whitening toothpaste and COAL_PWD, and CONT (p > 0.05). In addition, no differences were observed among the groups in Rv (p > 0.05). Conversely, enamel wear was higher for TiO2, COAL, COAL+TiO2, and COAL_PWD than for CONT. CONT showed the least enamel wear, whereas HP showed intermediate values. Representative 3D images and line profiles showed lower step-height and lower mean surface losses for the CONT and HP groups than for the other groups. Whitening toothpastes and COAL_PWD did not increase Sa or Rv compared with CONT, while CONT demonstrated lower enamel wear.

Remineralization, color stability and surface roughness of tooth enamel brushed with activated charcoal-based products

OBJECTIVE

To evaluate the effect of activated charcoal-based (AC) products on color alteration, remineralizing potential and surface roughness of dental enamel.

MATERIALS AND METHODS

Bovine incisors were cut into 6 × 6 × 2 mm fragments. Initial color (EasyShade, Vita) and surface roughness (Surfcorder SE1700, Kosakalab) readings were performed. Fragments were separated into five groups (n = 17) according to the treatment: Control: Fluoride toothpaste (Colgate Total 12, Colgate); Charcoal + NaF: AC toothpaste (ACT) with sodium fluoride (Colgate Natural Extracts, Colgate); Charcoal + MFP + n-HA: ACT with sodium monofluorophosphate and nanohydroxyapatite (Black is White, Curaprox); Charcoal: Fluoride-free ACT (ProActive, Hinode); and Charcoal powder: AC powder. Simulated toothbrushing was performed and final color and surface roughness readings were obtained. Fragments were then polished, and initial microhardness (HMV-2, Shimatzu) readings were done. Samples were artificially demineralized and brushed again. Final microhardness readings were taken. Data were statistically analyzed.

RESULTS

Fluoride-free charcoal presented the lowest surface roughness alteration (p < 0.05). Charcoal powder had the lowest color change (p < 0.05) and negative values for whiteness index for dentistry alteration. All the groups presented values below whiteness acceptability threshold and negative relative microhardness values. Control showed the highest remineralizing potential (p < 0.05).

CONCLUSIONS

ACPs did not produce color alteration different from the fluoride toothpaste, except for Charcoal powder that caused less color change. ACPs caused surface roughness alteration similar to the fluoride toothpaste. ACT with fluoride and AC powder did not have remineralizing potential.

CLINICAL SIGNIFICANCE

Activated charcoal-based products (ACP) promise effective tooth whitening and quick results, without teeth damage. In addition, some ACPs contain fluoride in toothpaste composition and promise rehardening potential. However, ACPs are not as effective as other whitening agents and can alter the surface roughness of the enamel. Even if the ACPs contain fluoride or other remineralizing agents, they might be ineffective.

Dynamicity, emerging patterns, and spatiotemporal trends of scientific production on the use of activated carbon in oral health: a scientometric study

BACKGROUND

The use of activated carbon (AC) in oral hygiene products has gained significant interest; however, its potential benefits for oral health remain uncertain. This study aimed to conduct a scientometric analysis to examine the dynamicity, emerging patterns, and trends over time in scientific production concerning the use of AC in oral health.

METHODS

The Web of Science database was searched for articles published between 2005 and 2022. Various bibliometric indicators, including the H-index, annual growth, Lotka's law, Bradford's law, and Sankey diagram, were used for data analysis. Overlay maps, timezone visualization, and three field plots were used to evaluate visualization patterns, time-temporal relationships, and trends. Information retrieval process was performed on March 11, 2023.

RESULTS

The analysis revealed that only six studies constituted the top references with the highest number of citations in recent years, with Brooks' 2017 study demonstrating the most significant increase in citation. The dual-map overlay demonstrated a close citation relationship between cluster 4 (Molecular Biology Immunology) and the areas of Environmental, Toxicology, and Nutrition. The visualization graph of publication patterns indicated the journals that accumulated the highest number of citations during the study period.

CONCLUSION

This scientometric study provides valuable insights into the use of AC in oral health and its impact on the field of dentistry. It determines the most productive journals, authors, and countries with the greatest influence. AC effectively removes pollutants and is gaining interest for use in dental effluent treatment. Thus, it may be a viable option for professionals.

In Vitro evaluation of the effects of whitening toothpastes on the color and surface roughness of different composite resin materials

BACKGROUND

The aim of this study was to evaluate the effects of traditional and whitening toothpastes on the color and surface roughness of different composite resin materials.

METHODS

Eighty disc-shaped samples were prepared for each of the following composite resins: nano-hybrid (Filtek Ultimate Universal; 3 M/ESPE, Saint Paul, USA), micro-hybrid (Charisma Smart; Kulzer, Hanau, Germany) and supra-nano-filled (Omnichroma; Tokuyama, Tokyo, Japan). Each composite-resin sample was randomly divided into the following four subgroups (n = 20 per group): Group 1, control; Group 2, traditional toothpaste (Colgate Total 12; Colgate Palmolive, New York, USA); Group 3, peroxide-based toothpaste (Colgate Optic White; Colgate-Palmolive, New York, USA); and Group 4, blue covarine-based toothpaste (Meridol Gentle White; CP-GABA, Hamburg, Germany). The samples for the toothpaste subgroups were immersed in a coffee solution for 10 min and washed twice a day before each brushing cycle. The specimens were brushed for 30 days. Color analyses were performed using a spectrophotometer (SpectroShade Micro, MHT, Italy). Surface roughness analyses were conducted using a profilometer (Surftest SJ-210 Mitutoyo, Tokyo, Japon). The color and surface roughness analyses were performed at baseline and 1, 7 and 30 days after each treatment. Furthermore, surface topography analysis was performed using Scanning Electron Microscopy (FEG 250-FeiQuanta, the Netherlands). The data were analysed with a three-way robust ANOVA and Bonferroni post-hoc correction (p < 0.05).

RESULTS

The smallest color change was observed for the micro-hybrid composite resin, and the greatest color change was observed for the nano-hybrid composite resin. Based on the tested composite resin samples, the greatest color change was obtained after using blue covarine-based toothpaste, while the smallest color change was observed after using peroxide-based toothpaste. Moreover, the supra-nano-filled composite resin samples exhibited the lowest roughness values (robust ANOVA test, p < 0.001). There was no statistically significant difference between the mean values of roughness for the composite, group and time interaction (p = 0.937).

CONCLUSION

Charisma Smart composite resin exhibited significantly lower staining than all the other composite resins tested after using all toothpastes included in the study. Further laboratory and clinical studies are needed to fully understand the long-term effectiveness of whitening toothpaste on composite resin materials.

Impact of different brushing/abrasion protocols on erosive tooth wear for in vitro studies

OBJECTIVE

To investigate the influence of different toothbrushing (with dentifrice) protocols on the progression of erosive tooth wear for in vitro studies.

DESIGN

Bovine enamel specimens were randomly distributed into 12 experimental groups (n = 10), according to the study factors: (1) brushing movement (horizontal or circular); (2) slurry diluent (artificial saliva or distilled water); (3) toothpaste dilution ratio (1:2, 1:3 or 1:4). A 5-day erosion-abrasion cycling model was performed, each consisting of 4 erosive challenges (0.3 % citric acid, pH=2.6) followed by 60 min exposure to artificial saliva. Brushing with fluoride toothpaste (15 s, 1400 ppm F^-, AmF) was carried out 2x/day. Enamel surface loss (SL) was determined by optical profilometry. Data were statistically analyzed with three-way ANOVA and Tukey tests (α = 0.05).

RESULTS

SL was lower for the horizontal movement than for the circular (p = 0.044). There were no significant differences among the dilution ratios for artificial saliva. For distilled water, the more concentrated slurry (1:2) presented greater surface loss than the less concentrated slurries (1:3 and 1:4, p = 0.049 and p = 0.014, respectively). Dilutions with artificial saliva at ratios 1:3 and 1:4 presented higher surface loss than with distilled water (p = 0.008 and p < 0.001, respectively); however, for 1:2 ratio, there were no significant differences between the diluents.

CONCLUSIONS

The in vitro progression of enamel SL was influenced by the brushing movement, as well as the combination of the dilution ratio and the diluent of the toothpaste slurry, and therefore, all these factors must be considered when comparing results from different studies.

In vitro assessment of activated charcoal-based dental products

OBJECTIVE

Assess the effects of activated charcoal-based products on whitening and changes on dental enamel surface.

MATERIAL AND METHODS

Fifty-two blocks of bovine dental enamel were randomly distributed in four groups (n = 13): brushing with activated charcoal-based powder (PW); brushing with activated charcoal-based dentifrice (AC); brushing with a conventional dentifrice containing 1450 ppm of fluoride (CD); and whitening with 10% carbamide peroxide (CP). Color, microhardness, and surface alteration were analyzed at baseline and after 14 days of treatment. Three samples per group were randomly selected and examined using scanning electron microscopy (SEM) to analyze the morphology.

RESULTS

PW exhibited greater color change for the ΔE₀₀ , ΔWID, Δb* and ΔL* parameters than other groups (p < 0.05). After treatment, microhardness decreased in AC and CP groups (p < 0.05). Also, PW and AC groups showed more surface alteration than CD and CP (p < 0.001). Changes in the morphology of dental enamel were observed by SEM in PW and AC groups.

CONCLUSION

Activated charcoal-based products showed a lower whitening effect than 10% carbamide peroxide. These products also influenced dental enamel microhardness, resulting in greater surface alteration.

CLINICAL SIGNIFICANCE

Activated charcoal-based products promoted minimum whitening effects with significant enamel surface alteration. The 10% carbamide peroxide was more effective for whitening and caused slight enamel surface alteration.

Effect of Activated Charcoal Toothpaste on Color Stability of Bleached Teeth Immersed in Different Drinks

OBJECTIVE

This study aimed to evaluate the effect of activated charcoal toothpaste on the color stability of teeth subjected to tooth bleaching and pigmenting agents.

METHODS

A total of 120 bovine crowns were randomly divided into 12 groups (n=10) according to two study factors: staining solutions (three levels): saliva (control), coffee, and red wine; and toothpaste (four levels): BPC, Bianco Pro Clinical (Bianco Oral Care) (Control); BIW, Black is White (Curaprox); BCA, Bianco Carbon (Bianco Oral Care); and NAT, Natural Suavetex (Suavetex). The samples were subjected to office bleaching with a 35% hydrogen peroxide-based gel (Whiteness HP Blue, FGM), followed by immersion in the solution for 45 minutes per day and daily toothbrushing for 7 days. The color (ΔE) and luminosity changes (ΔL*) were measured using reflectance spectroscopy (Vita EasyShade). The CIE values (L*, a*, b*) were measured at baseline after bleaching (T0) and immediately after immersion in solution each day (Ti1-Ti7) and after all toothbrushing cycles (Tb1-Tb7). ΔE and ΔL were analyzed using a two-way analysis of variance and Tukey's test (α=0.05). The clinically unacceptable level of ΔE > 3.3 was used to evaluate the color change.

RESULTS

The color change was significantly influenced by the staining solutions and toothpastes (p<0.001). The color change (ΔE) was significantly higher when immersed in wine than in coffee, and lower ΔE values were observed for artificial saliva (control), irrespective of the toothpaste used. In artificial saliva, BPC, BIW, and BCA resulted in significantly lower ΔE values than NAT, which presented a clinically unacceptable level of dental color change (ΔE>3.3). Coffee resulted in a lower (L*) reduction than wine, irrespective of the toothpaste used.

CONCLUSION

Charcoal toothpastes resulted in a color change on the surface of the tooth enamel (ΔE). The bleaching effect of the charcoal toothpastes and control evaluated in this study partially reduced the color changes on the surface of the tooth enamel caused by staining solutions but was unable to reestablish the measured values to the baseline. For teeth immersed in artificial saliva, the color change was not noticeable in BCA, BIW, and control-BPC (ΔE≥3.3), except for NAT, which showed a significant color change.

Characterization of whitening toothpastes and their effect on the physical properties of bulk-fill composites

To characterize activated charcoal and 2% hydrogen peroxide-based toothpastes and investigate their effects on roughness, color change, and gloss of bulk-fill composite resin. Composite resin specimens (Aura Bulk Fill, SDI) were subjected to 5,000 brushing cycles with regular toothpaste (Colgate Total 12, [RT]), activated charcoal toothpaste (Bianco Dental Carbon, [AC]), or hydrogen peroxide-containing toothpaste (Colgate Luminous White Advanced, [HP]), with or without coffee exposure. The pH, particle characterization by scanning electron microscopy (SEM), and weight% of solid particles in the toothpaste were assessed. Roughness (Ra) was evaluated using a surface profile-measuring device, color change (∆Eab/∆E00) by reflectance spectrophotometer, and gloss unit (GU) by glossmeter. Kruskal-Wallis, Dunn, Friedman, and Nemenyi tests were used, and the correlation coefficient test was performed between Ra and GU (α=0.05). RT presented a higher Ra after brushing and did not change after staining with coffee; moreover, the ∆Eab/∆E00 values were higher for RT than HP. Regarding gloss, AC and HP obtained higher values compared to RT. A significant negative correlation between gloss and Ra was found for RT exposed to coffee. All toothpastes had a neutral pH; however, RT had the largest percentage of solids by weight. SEM images showed particles of many sizes: irregular shape (RT), more regular particles (AC), and spherical clusters (HP). Although surface roughness, color change, and gloss may compromise the longevity of restorations, the whitening toothpastes tested did not promote more morphology changes than regular toothpastes.

A 58S bioactive glass for dentin hypersensitivity and erosive tooth wear: An in vitro study

OBJECTIVES

To assess the effect of an experimental 58S bioactive glass on dentin permeability (dP) and erosive tooth wear (dentin surface loss - dSL).

METHODS

58S bioactive glass was synthetized using a sol-gel methodology, following by lyophilization and calcination, then mixed with phosphoric acid to obtain a paste (BGP). Forty-eight dentin disks (1 mm-thick) were used for dP, and 48 dentin slabs (3 mm × 3 mm) for dSL, which were assessed at three time intervals: post-EDTA (5 min in 17% EDTA solution); post-treatment (C: distilled water; BGP: experimental bioactive glass paste; NP: Nupro prophylaxis paste; CXT: Clinpro XT varnish); and post-erosive/abrasive cycling. Data were statistically analyzed (α=0.05).

RESULTS

For dP and dSL, Groups did not differ significantly post-EDTA (p>0.05). Post-treatment, all groups showed lower dP than C (p<0.05), without differing significantly among them. For the dSL analysis, Groups C, BGP and NP did not differ significantly, showing lower values than CXT (p<0.05). Post-cycling, C continued to show the highest dP (p<0.05). Specimens from Group CXT had the lowest dP and did not differ from NP (p=0.86) which did not differ from BGP (p=0.193). For C and BGP, dP value was higher post-cycling than post-treatment (p<0.05). For NP and CXT, these experimental times did not differ (p>0.05). Post-cycling, dSL for C, BGP and NP did not differ significantly; values were higher than those for CXT (p<0.05).

CONCLUSIONS

BGP reduced dP after application, with a reduced effect after cycling. Nonetheless, it was not able to protect dentin against erosive tooth wear.

CLINICAL SIGNIFICANCE

Minimizing dentin hypersensitivity is a challenge in the field of dentistry. The development of alternative products with potential to obliterate dentinal tubules and provide resistance to chemical/mechanical stimuli is, thus, highly desirable. We have proposed a material able to reduce dentin permeability, which has emerged as a promising alternative for this purpose.

Thr in vitro Effect of Dentifrices With Activated Charcoal on Eroded Teeth

AIM

The objective of this research was to compare the abrasive potential of dentifrices containing activated charcoal with those of a conventional dentifrice on the development of erosive tooth wear (ETW) in vitro.

METHODS

Enamel and dentin samples were divided into toothpastes (n = 12): group (G)1-Colgate Triple Action (1450 ppm F) (positive control); G2-Colgate Natural Extracts (1450 ppm F); G3-Colgate Luminous White Activated Carbon (1450 ppm F); G4-Oral-B Whitening Therapy Charcoal (1100 ppm F); G5-Oral-B 3D White Mineral Clean (1100 ppm F); G6-Curaprox Black Is White (950 ppm F); and G7-erosion only (no abrasion, negative control). All samples were submitted to erosive pH cycles and G1 to G6 to abrasive challenges (15 seconds) using toothpastes' slurries plus 45 seconds of treatment for 7 days. The final profile was overlaid to the baseline one for the ETW calculation (µm). The data were subjected to analysis of variance/Tukey or Kruskal-Wallis/Dunn tests (P < .05).

RESULTS

Oral-B 3D White (13.0 ± 1.0, 9.37 [1.36] μm), Oral-B Whitening Therapy (15.1 ± 1.2, 8.58 [1.71] μm), and Colgate Luminous White (13.6 ± 1.0, 7.46 [0.94] μm) toothpastes promoted the greatest enamel and dentin wear. On the other hand, Colgate Triple Action (12.2 ± 1.2, 5.30 [1.26] μm), Colgate Natural Extracts (10.8 ± 1.1, 4.16 [1.11] μm), and Curaprox Black Is White (11.5 ± 1.5, 4.06 [0.92] μm) toothpastes promoted lower wear values, similar to erosion only (4.16 [0.94] μm) in the case of dentin but not enamel (7.1 ± 0.8 μm).

CONCLUSIONS

Toothpastes containing charcoal combined with pyrophosphate may have a high abrasive effect on eroded tooth surfaces. Many patients influenced by digital marketing use toothpastes containing activated charcoal with the aim of bleaching their teeth. However, care should be taken when using these products, as they may have a high abrasive effect.

EFFECTIVENESS AND ABRASIVENESS OF ACTIVATED CHARCOAL AS A WHITENING AGENT: A SYSTEMATIC REVIEW OF IN VITRO STUDIES

INTRODUCTION

Tooth whitening is currently one of the most requested treatments to change the color of teeth. There are different types of whitening in the dental office and at home. There are also many whitening agents on the market. Nowadays, the public has shown great interest in a new natural compound: activated charcoal. It has an abrasive effect and it is included in toothpastes to whiten teeth quickly and easily.

OBJECTIVES

The main objective of the systematic review is to perform a qualitative synthesis of the available literature on the use of activated charcoal-based toothpaste for tooth whitening.

MATERIAL AND METHODS

An electronic search was carried out in PubMed, Web of Science, and Scopus databases. The search included the terms (charcoal-based OR activated charcoal OR charcoal OR soot) AND (toothpaste OR dentifrices OR bleaching OR oral hygiene OR enamel OR teeth). Inclusion criteria were articles that were published in English, that included activated charcoal toothpastes, that assessed the efficacy of activated charcoal bleaching and/or the safety of using activated charcoal toothpastes, that were conducted on humans or extracted teeth regardless of their origin and the year of publication.

RESULTS

Out of 208 articles, 11 met the inclusion criteria, the Risk of Bias of the selected studies was determined as medium-high. Regarding the whitening effect, there is a variety of results depending on the study: in some there are no significant differences between the proposed treatments and in others activated charcoal is not the most whitening agent. Regarding the abrasive effect, most studies agree that activated charcoal toothpaste has a higher abrasive potential.

CONCLUSION

Toothpastes based on activated charcoal possess a lower whitening effect than other alternatives and can be considered as less safe due to its high abrasive potential.

Surface Roughness and Color Stability of 3D-Printed Denture Base Materials after Simulated Brushing and Thermocycling

Three-dimensional (3D) printing is increasingly used to fabricate denture base materials. However, information on the effect of simulated brushing and thermocycling on the surface roughness and color stability of 3D-printed denture base materials is lacking. The aim of this study was to evaluate the effect of brushing and thermocycling on the surface roughness and color stability of 3D-printed denture base materials and to compare with those of milled and heat-polymerized denture base resins. Disk-shaped specimens (Ø 10 mm × 2 mm) were prepared from 4 different denture base resins (NextDent Denture 3D+ (ND); Denturetec (SC); Polident d.o.o (PD); Promolux (CNV)) (n = 10). Surface roughness (R_a) values were measured before and after polishing with a profilometer. Initial color coordinates were measured by using a spectrophotometer after polishing. Specimens were then consecutively subjected to simulated brushing (10,000 cycles), thermocycling (10,000 cycles), and brushing (10,000 cycles) again. R_a and color coordinates were measured after each interval. Color differences (ΔE₀₀) between each interval were calculated and these values were further evaluated considering previously reported perceptibility (1.72 units) and acceptability (4.08 units) thresholds. Data were analyzed with Friedman, Kruskal-Wallis, and Mann-Whitney U tests (α = 0.05). R_a (p ≥ 0.051) and ΔE₀₀ (p ≥ 0.061) values among different time intervals within each material were similar. Within each time interval, significant differences in R_a (p ≤ 0.002) and ΔE₀₀ values (p ≤ 0.001) were observed among materials. Polishing, brushing, and thermocycling resulted in acceptable surface roughness for all materials that were either similar to or below 0.2 µm. Color of ND printed resin was affected by brushing and thermocycling. All materials had acceptable color stability when reported thresholds are considered.

Is whitening toothpaste safe for dental health?: RDA-PE method

The relative dentin abrasivity-profilometry equivalent values were compared using non-contact profilometry with three subtypes of regular toothpaste and two subtypes of whitening toothpaste containing sodium bicarbonate and 35% hydrogen peroxide. Bovine dentin specimens were assigned to six groups: regular toothpaste (R): R1 (BAMBOO SALT GUM OINTMENT); R2 (MEDIAN TARTAR ORIGINAL); R3 (PERIOE Alpha), Reference slurry: RS (calcium pyrophosphate), whitening toothpaste (W): W1 (NET. WT); W2 (Vussen 28 WHITENING). Relative dentin abrasion-profilometry equivalent (RDA-PE) was determined by brushing 10,000 times (n=8). The pH of the toothpaste was measured (n=5) and the abrasive constituents of the toothpaste was analyzed by FE-SEM and EDS. The RDA-PE values ranged from 26 to166, and the pH level ranges were 4.928-9.153. The RDA-PE value of the whitening toothpaste containing hydrogen peroxide was not high compared with that of the regular toothpaste. The RDA-PE values of whitening toothpaste could vary depending on the mechanism and ingredients of the whitening agents.

Recent developments in the use of activated charcoal in medicine

One of the raw forms of graphite is activated charcoal which has an extensive surface area allowing for the adsorption of a wide range of chemicals. It possesses the strongest physical adsorption forces of the available materials, as well as the largest volume of adsorbing porosity. Activated charcoal acts as an adsorbent, collecting and storing substances in the gastrointestinal tract, reducing or blocking absorption in the bloodstream. The ingested toxins interact with charcoal by recycling toxins in the intestinal cavity. In cases where the drug has not been absorbed from the abdominal system, it is recirculated through the liver and intestines or by means of passive diffusion or active secretion. The article aims to review the most recent advances in the use of the activated charcoal, including the dose, how charcoal acts in the body, the mechanism of action, administration, contraindications, as well as the impact of various factors on the adsorption process. In addition, we also discussed numerous medical applications of activated charcoal.

Impact of desensitizing/whitening toothpastes on tooth color change after abrasion and erosion-abrasion

OBJECTIVE

To evaluate the impact of desensitizing toothpastes (D), their whitening versions (DW) and whitening toothpastes (W) on tooth color change.

METHODS

Tooth specimens were allocated into 11 groups (n = 10): 1. Artificial saliva (control); 2. Sensodyne Repair & Protect (SRP-D); 3. Sensodyne Repair & Protect Whitening (SRP-DW); 4. Colgate Sensitive Pro-Relief (CSPR-D); 5. Colgate Sensitive Pro-Relief Real White (CSPR-DW); 6. Colgate Total 12 (CT12); 7. Colgate Total 12 Whitening (CT12-W); 8. Sensodyne True White (ST-W); 9. Curaprox Black Is White (CB-W); 10.Oral-B 3D White Perfection (OB3D-W) and 11. Erosion-only. They were submitted to two models: A. abrasion; B. erosion/abrasion. Color change (ΔE₀₀ ), ΔL, Δa, and Δb were determined with a spectrophotometer. Data were statistically evaluated (α = 0.05).

RESULTS

For both models, ∆E₀₀ of D did not differ significantly from DW. An overall decrease in luminosity (-∆L) and increase (+∆b) in yellowness of the tooth occurred. In abrasion, all groups reduced redness (-∆a) and only SRP-DW differed from control (p = 0.016), but for ∆E₀₀ , ∆L and ∆b, all toothpastes did not differ from the control. In erosion/abrasion, CB-W showed significantly lower ∆E₀₀ and ∆b than the control (∆E₀₀ : p = 0.026; ∆b: p = 0.005) and SRP-D (∆E₀₀ : p = 0.028; ∆b: p = 0.025). Only SRP-DW, CSPR-DW, ST-W, CB-W, and erosion-only had increased redness (+∆a), but none differed from control.

CONCLUSIONS

The toothpastes did neither promote whitening nor avoid the yellowish aspect of the tooth after abrasion and erosion-abrasion, regardless of their claim.

CLINICAL SIGNIFICANCE

Desensitizing and/or whitening toothpastes induced similar changes on tooth color, without promoting whitening effect or reduction in its yellowish aspect.

Charcoal-based dentifrices and powders: analyses of product labels, Instagram engagement, and altmetrics

This study identified charcoal-based dentifrices and abrasive powders sold in Brazil and analyzed their label information. The products were searched in four online shopping platforms. The same products were searched on Instagram and their engagement metrics were investigated. Furthermore, a literature review of international publications assessing charcoal dentifrices and powders was conducted, and altmetrics were collected (Altmetric and PlumX). Thirty-six products were found with prices between $0.4-22 USD. Most frequent words in product description were sodium, stain, whitening, oil, xylitol, and coconut. Only 3 products contained fluoride. Bactericidal, antiviral, antifungal, and anti-inflammatory activities were indicated, in addition to non-scientific claims such as calming teeth or increasing oral immunity. In total, 72% of products had Instagram profiles, which generally showed low engagement rates (81%) and medium audience quality scores (65%). Twenty-two articles were found in the literature, from which 21 were in vitro studies. The single clinical study was sponsored by a charcoal product and had no control group. In total, 23% of studies showed positive results and 55% reported negative results for the charcoal products, which included no whitening ability, increased roughness, surface alterations, and lower demineralization prevention ability. Altmetric scores for the included articles varied from 0 to 55, with 40.9% of studies mentioned online. In conclusion, charcoal-based products are using marketing strategies on Instagram but their current engagement with the public is not high. Consumers are being exposed to charcoal products whose potential risks to health are still unknown.