A Critical Review of Modern Concepts for Teeth Whitening
Abstract
:1. Introduction
2. Staining of the Tooth Surface
3. Whiteness of Teeth
4. In-Office Teeth Whitening Using Peroxides
- (I)
- H2O2 → H2O + ½ O2.
- (II)
- H2O2 + 2 H+ + 2 e− → 2 H2O, or
- (III)
- H2O2 + 2 e− → 2 OH−.
- (IV)
- MgO2 + 2 H2O → Mg(OH)2 + H2O2 (magnesium peroxide);
- (V)
- CaO2 + 2 H2O → Ca(OH)2 + H2O2 (calcium peroxide);
- (VI)
- Na2(CO4) + H2O → Na2CO3 + H2O2 (sodium percarbonate);
- (VII)
- CO(NH2)2·H2O2 → CO(NH2)2 + H2O2 (carbamide peroxide, an adduct of urea and hydrogen peroxide, contains about 36 wt% hydrogen peroxide).
5. Whitening Toothpastes
6. Potential Risks of Teeth Whitening Concepts
7. Conclusions
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
References
- Dorozhkin, S.V.; Epple, M. Biological and medical significance of calcium phosphates. Angew. Chem. Int. Ed. 2002, 41, 3130–3146. [Google Scholar] [CrossRef]
- Enax, J.; Epple, M. Synthetic hydroxyapatite as a biomimetic oral care agent. Oral Health Prev. Dent. 2018, 16, 7–19. [Google Scholar] [PubMed]
- Meyer, F.; Amaechi, B.T.; Fabritius, H.-O.; Enax, J. Overview of calcium phosphates used in biomimetic oral care. Open Dent. J. 2018, 12, 406–423. [Google Scholar] [CrossRef] [PubMed]
- Lowenstam, H.A.; Weiner, S. On Biomineralization; Oxford University Press: New York, NY, USA, 1989. [Google Scholar]
- Brown, P.W.; Constantz, B. Hydroxyapatite and Related Materials; CRC Press: Boca Raton, FL, USA, 1994. [Google Scholar]
- Forien, J.-B.; Zizak, I.; Fleck, C.; Petersen, A.; Fratzl, P.; Zolotoyabko, E.; Zaslansky, P. Water-mediated collagen and mineral nanoparticle interactions guide functional deformation of human tooth dentin. Chem. Mater. 2016, 28, 3416–3427. [Google Scholar] [CrossRef]
- Forien, J.B.; Fleck, C.; Cloetens, P.; Duda, G.; Fratzl, P.; Zolotoyabko, E.; Zaslansky, P. Compressive residual strains in mineral nanoparticles as a possible origin of enhanced crack resistance in human tooth dentin. Nano Lett. 2015, 15, 3729–3734. [Google Scholar] [CrossRef] [PubMed]
- LeGeros, R.Z. Apatites in biological systems. Prog. Cryst. Growth Charact. 1981, 4, 1–45. [Google Scholar] [CrossRef]
- Jowett, A.K.; Marlow, I.; Rawlinson, A. A double blind randomised controlled clinical trial comparing a novel anti-stain and calculus reducing dentifrice with a standard fluoride dentifrice. J. Dent. 2013, 41, 313–320. [Google Scholar] [CrossRef] [PubMed]
- Hannig, M.; Hannig, C. Der initiale orale Biofilm—Pathogen oder protektiv? Oralprophylaxe Kinderzahnheilkunde 2007, 29, 73–82. [Google Scholar]
- Algarni, A.A.; Ungar, P.S.; Lippert, F.; Martinez-Mier, E.A.; Eckert, G.J.; Gonzalez-Cabezas, C.; Hara, A.T. Trend-analysis of dental hard-tissue conditions as function of tooth age. J. Dent. 2018, 74, 107–112. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Joiner, A. Whitening toothpastes: A review of the literature. J. Dent. 2010, 38 (Suppl. 2), e17–e24. [Google Scholar] [CrossRef]
- Fejerskov, O.; Kidd, E. Dental Caries: The Disease and its Clinical Management; Wiley: Hoboken, NJ, USA, 2009. [Google Scholar]
- Kassebaum, N.J.; Bernabe, E.; Dahiya, M.; Bhandari, B.; Murray, C.J.; Marcenes, W. Global burden of untreated caries: A systematic review and metaregression. J. Dent. Res. 2015, 94, 650–658. [Google Scholar] [CrossRef] [PubMed]
- Meyer, F.; Enax, J. Early childhood caries: Epidemiology, aetiology, and prevention. Int. J. Dent. 2018, 2018, 1–7. [Google Scholar] [CrossRef] [PubMed]
- Meyer, F.; Karch, A.; Schlinkmann, K.M.; Dreesman, J.; Horn, J.; Rubsamen, N.; Sudradjat, H.; Schubert, R.; Mikolajczyk, R. Sociodemographic determinants of spatial disparities in early childhood caries: An ecological analysis in Braunschweig, Germany. Community Dent. Oral Epidemiol. 2017, 45, 442–448. [Google Scholar] [CrossRef] [PubMed]
- Van Loveren, C. Toothpastes; Karger: Basel, Switzerland, 2013; Volume 23. [Google Scholar]
- Yaacob, M.; Worthington, H.V.; Deacon, S.A.; Deery, C.; Walmsley, A.D.; Robinson, P.G.; Glenny, A.M. Powered versus manual toothbrushing for oral health. Cochrane Database Syst. Rev. 2014, Cd002281. [Google Scholar] [CrossRef] [PubMed]
- Epple, M.; Enax, J. Moderne Zahnpflege aus chemischer Sicht. Chem. Unserer Zeit 2018, 52, 218–228. [Google Scholar] [CrossRef]
- Schlagenhauf, U.; Kunzelmann, K.-H.; Hannig, C.; May, T.W.; Hösl, H.; Gratza, M.; Viergutz, G.; Nazet, M.; Schamberger, S.; Proff, P. Impact of a non-fluoridated microcrystalline hydroxyapatite dentifrice on enamel caries progression in highly caries-susceptible orthodontic patients: A randomized, controlled 6-month trial. J. Invest. Clin. Dent. 2019, 10, e12399. [Google Scholar] [CrossRef]
- Marsh, P.D. Contemporary perspective on plaque control. Br. Dent. J. 2012, 212, 601–606. [Google Scholar] [CrossRef] [Green Version]
- Cieplik, F.; Kara, E.; Muehler, D.; Enax, J.; Hiller, K.-A.; Maisch, T.; Buchalla, W. Antimicrobial efficacy of alternative compounds for use in oral care towards biofilms from caries-associated bacteria in vitro. MicrobiologyOpen 2018, 695, 1–10. [Google Scholar] [CrossRef]
- Meireles, S.S.; Goettems, M.L.; Dantas, R.V.; Bona, A.D.; Santos, I.S.; Demarco, F.F. Changes in oral health related quality of life after dental bleaching in a double-blind randomized clinical trial. J. Dent. 2014, 42, 114–121. [Google Scholar] [CrossRef]
- Pavicic, D.K.; Kolceg, M.; Lajnert, V.; Pavlic, A.; Brumini, M.; Spalj, S. Changes in quality of life induced by tooth whitening are moderated by perfectionism: A randomized, double-blind, placebo-controlled trial. Int. J. Prosthodont. 2018, 31, 394–396. [Google Scholar] [CrossRef]
- Silva, E.M.D.; Maia, J.N.D.S.M.; Mitraud, C.G.; Russo, J.D.; Poskus, L.T.; Guimaraes, J.G.A. Can whitening toothpastes maintain the optical stability of enamel over time? J. Appl. Oral Sci. 2018, 26, e20160460. [Google Scholar] [CrossRef]
- Viscio, D.; Gaffar, A.; Fakhry-Smith, S.; Xu, T. Present and future technologies of tooth whitening. Compend. Contin. Educ. Dent. Suppl. 2000, 21, S36–S43. [Google Scholar]
- Carey, C.M. Tooth whitening: What we now know. J. Evid. Based Dent. Pract. 2014, 14, 70–76. [Google Scholar] [CrossRef]
- Andreasen, F.M. Transient apical breakdown and its relation to color and sensibility changes after luxation injuries to teeth. Dent. Traumatol. 1986, 2, 9–19. [Google Scholar] [CrossRef]
- Lippert, F. An introduction to toothpaste—Its purpose, history and ingredients. Monogr. Oral Sci. 2013, 23, 1–14. [Google Scholar]
- Fearon, J. Tooth whitening: Concepts and controversies. J. Ir. Dent. Assoc. 2007, 53, 132–140. [Google Scholar]
- Sherwood, I.A. Fluorosis varied treatment options. J. Conserv. Dent. 2010, 13, 47–53. [Google Scholar] [CrossRef] [Green Version]
- Addy, M.; Moran, J. Mechanisms of stain formation on teeth, in particular associated with metal ions and antiseptics. Adv. Dent. Res. 1995, 9, 450–456. [Google Scholar] [CrossRef]
- Attin, T.; Paqué, F.; Ajam, F.; Lennon, Á.M. Review of the current status of tooth whitening with the walking bleach technique. Int. Endod. J. 2003, 36, 313–329. [Google Scholar] [CrossRef] [Green Version]
- Joiner, A.; Hopkinson, I.; Deng, Y.; Westland, S. A review of tooth colour and whiteness. J. Dent. 2008, 36, S2–S7. [Google Scholar] [CrossRef]
- Gron, P.; Van Campen, G.J.; Lindstrom, I. Human dental calculus. Inorganic chemical and crystallographic composition. Arch. Oral Biol. 1967, 12, 829–837. [Google Scholar]
- Jones, C.G. Chlorhexidine: Is it still the gold standard? Periodontol. 2000 1997, 15, 55–62. [Google Scholar] [CrossRef]
- Ellingsen, J.E.; Eriksen, H.M.; Rolla, G. Extrinsic dental stain caused by stannous fluoride. Scand. J. Dent. Res. 1982, 90, 9–13. [Google Scholar] [CrossRef]
- Kensche, A.; Holder, C.; Basche, S.; Tahan, N.; Hannig, C.; Hannig, M. Efficacy of a mouthrinse based on hydroxyapatite to reduce initial bacterial colonisation in situ. Arch. Oral Biol. 2017, 80, 18–26. [Google Scholar] [CrossRef]
- Joiner, A.; Luo, W. Tooth colour and whiteness: A review. J. Dent. 2017, 67, S3–S10. [Google Scholar] [CrossRef]
- Stookey, G.K.; Burkhard, T.A.; Schemehorn, B.R. In vitro removal of stain with dentifrices. J. Dent. Res. 1982, 61, 1236–1239. [Google Scholar] [CrossRef]
- Joiner, A. Tooth colour: A review of the literature. J. Dent. 2004, 32, 3–12. [Google Scholar] [CrossRef]
- Terezhalmy, G.T.; Walters, P.A.; Bartizek, R.D.; Grender, J.M.; Biesbrock, A.R. A clinical evaluation of extrinsic stain removal: A rotation-oscillation power toothbrush versus a dental prophylaxis. J. Contemp. Dent. Pract. 2008, 9, 1–8. [Google Scholar] [CrossRef]
- Demarco, F.F.; Meireles, S.S.; Masotti, A.S. Over-the-counter whitening agents: a concise review. Braz. Oral Res. 2009, 23 (Suppl. 1), 64–70. [Google Scholar] [CrossRef] [Green Version]
- Vaz, M.M.; Lopes, L.G.; Cardoso, P.C.; Souza, J.B.; Batista, A.C.; Costa, N.L.; Torres, E.M.; Estrela, C. Inflammatory response of human dental pulp to at-home and in-office tooth bleaching. J. Appl. Oral Sci. 2016, 24, 509–517. [Google Scholar] [CrossRef]
- Yao, C.S.; Waterfield, J.D.; Shen, Y.; Haapasalo, M.; Macentee, M.I. In vitro antibacterial effect of carbamide peroxide on oral biofilm. J. Oral Microbiol. 2013, 5, 20392. [Google Scholar]
- Marson, F.C.; Sensi, L.G.; Vieira, L.C.; Araujo, E. Clinical evaluation of in-office dental bleaching treatments with and without the use of light-activation sources. Oper. Dent. 2008, 33, 15–22. [Google Scholar] [CrossRef]
- Enax, J.; Epple, M. Die Charakterisierung von Putzkörpern in Zahnpasten. Deutsche Zahnärztliche Zeitschrift 2018, 73, 100–108. [Google Scholar]
- Harks, I.; Jockel-Schneider, Y.; Schlagenhauf, U.; May, T.W.; Gravemeier, M.; Prior, K.; Petersilka, G.; Ehmke, B. Impact of the daily use of a microcrystal hydroxyapatite dentifrice on de novo plaque formation and clinical/microbiological parameters of periodontal health. A randomized trial. PLoS ONE 2016, 11, e0160142. [Google Scholar] [CrossRef]
- Hagenfeld, D.; Prior, K.; Harks, I.; Jockel-Schneider, Y.; May, T.W.; Harmsen, D.; Schlagenhauf, U.; Ehmke, B. No differences in microbiome changes between anti-adhesive and antibacterial ingredients in toothpastes during periodontal therapy. J. Periodont. Res. 2019, (in press). [Google Scholar] [CrossRef]
- Niwa, M.; Sato, T.; Li, W.; Aoki, H.; Daisaku, T. Polishing and whitening properties of toothpaste containing hydroxyapatite. J. Mater. Sci. Mater. Med. 2001, 12, 277–281. [Google Scholar] [CrossRef]
- Lelli, M.; Putignano, A.; Marchetti, M.; Foltran, I.; Mangani, F.; Procaccini, M.; Roveri, N.; Orsini, G. Remineralization and repair of enamel surface by biomimetic Zn-carbonate hydroxyapatite containing toothpaste: A comparative in vivo study. Front. Physiol. 2014, 5, 333. [Google Scholar] [CrossRef]
- Fabritius-Vilpoux, K.; Enax, J.; Herbig, M.; Raabe, D.; Fabritius, H.O. Quantitative affinity parameters of synthetic hydroxyapatite and enamel surfaces in vitro. Bioinspired Biomim. Nanobiomater. 2019, 8, 141–153. (in press). [Google Scholar] [CrossRef] [Green Version]
- Dabanoglu, A.; Wood, C.; Garcia-Godoy, F.; Kunzelmann, K.H. Whitening effect and morphological evaluation of hydroxyapatite materials. Am. J. Dent. 2009, 22, 23–29. [Google Scholar]
- Jin, J.; Xu, X.; Lai, G.; Kunzelmann, K.H. Efficacy of tooth whitening with different calcium phosphate-based formulations. Eur. J. Oral Sci. 2013, 121, 382–388. [Google Scholar] [CrossRef]
- Kim, B.I.; Jeong, S.H.; Jang, S.O.; Kim, K.N.; Kwon, H.K.; Park, Y.D. Tooth whitening effect of toothpastes containing nano-hydroxyapatite. Key Eng. Mater. 2006, 309, 541–544. [Google Scholar]
- Bommer, C.; Flessa, H.P.; Xu, X.; Kunzelmann, K.H. Hydroxyapatite and self-assembling peptide matrix for non-oxidizing tooth whitening. J. Clin. Dent. 2018, 29, 57–63. [Google Scholar]
- Schemehorn, B.R.; Moore, M.H.; Putt, M.S. Abrasion, polishing, and stain removal characteristics of various commercial dentifrices in vitro. J. Clin. Dent. 2011, 22, 11–18. [Google Scholar]
- LeGeros, R.Z. Chemical and crystallographic events in the caries process. J. Dent. Res. 1990, 69, 567–574, 634–636. [Google Scholar] [CrossRef]
- LeGeros, R.Z. Biological and synthetic apatites. In Hydroxyapatite and Related Materials; Brown, P.W., Constantz, B., Eds.; CRC Press: Boca Raton, FL, USA, 1994; pp. 3–28. [Google Scholar]
- Terezhalmy, G.T.; Biesbrock, A.R.; Farrell, S.; Barker, M.L.; Bartizek, R.D. Tooth whitening through the removal of extrinsic stain with two sodium hexametaphosphate-containing whitening dentifrices. Am. J. Dent. 2007, 20, 309–314. [Google Scholar]
- Tao, D.; Smith, R.N.; Zhang, Q.; Sun, J.N.; Philpotts, C.J.; Ricketts, S.R.; Naeeni, M.; Joiner, A. Tooth whitening evaluation of blue covarine containing toothpastes. J. Dent. 2017, 67, S20–S24. [Google Scholar] [CrossRef]
- Amri, E.; Mamboya, F. Papain, a plant enzyme of biological importance: A review. Am. J. Biochem. Biotechnol. 2012, 8, 99–104. [Google Scholar]
- Kalyana, P.; Shashidhar, A.; Meghashyam, B.; Sreevidya, K.R.; Sweta, S. Stain removal efficacy of a novel dentifrice containing papain and Bromelain extracts—An in vitro study. Int. J. Dent. Hyg. 2011, 9, 229–233. [Google Scholar] [CrossRef]
- Clark, D.P.; Pazdernik, N.J. Chapter 9—Proteomics. In Biotechnology, 2nd ed.; Clark, D.P., Pazdernik, N.J., Eds.; Academic Cell: Boston, MA, USA, 2016. [Google Scholar]
- Adams, S.E.; Arnold, D.; Murphy, B.; Carroll, P.; Green, A.K.; Smith, A.M.; Brading, M.G. A randomised clinical study to determine the effect of a toothpaste containing enzymes and proteins on plaque oral microbiome ecology. Sci. Rep. 2017, 7, 43344. [Google Scholar] [CrossRef]
- Vaz, V.T.P.; Jubilato, D.P.; Oliveira, M.R.M.; Bortolatto, J.F.; Floros, M.C.; Dantas, A.A.R.; Oliveira Junior, O.B. Whitening toothpaste containing activated charcoal, blue covarine, hydrogen peroxide or microbeads: Which one is the most effective? J. Appl. Oral Sci. 2019, 27, e20180051. [Google Scholar] [CrossRef]
- Walsh, T.F.; Rawlinson, A.; Wildgoose, D.; Marlow, I.; Haywood, J.; Ward, J.M. Clinical evaluation of the stain removing ability of a whitening dentifrice and stain controlling system. J. Dent. 2005, 33, 413–418. [Google Scholar] [CrossRef]
- Imfeld, T.; Sener, B. In-vitro-Untersuchung der mechanischen Wirkung von Whitening-Zahnpasten des Schweizer Marktes. Acta Med. Dent. Helv. 1999, 4, 195–200. [Google Scholar]
- Markowitz, K. Pretty painful: Why does tooth bleaching hurt? Med. Hypotheses 2010, 74, 835–840. [Google Scholar] [CrossRef]
- Gillam, D.G. Dentine Hypersensitivity: Advances in Diagnosis, Management, and Treatment; Springer: Berlin/Heidelberg, Germany, 2015. [Google Scholar]
- Kielbassa, A.M.; Maier, M.; Gieren, A.K.; Eliav, E. Tooth sensitivity during and after vital tooth bleaching: A systematic review on an unsolved problem. Quintessence Int. 2015, 46, 881–897. [Google Scholar]
- Schulte, J.R.; Morrissette, D.B.; Gasior, E.J.; Czajewski, M.V. The effects of bleaching application time on the dental pulp. J. Am. Dent. Assoc. 1994, 125, 1330–1335. [Google Scholar] [CrossRef]
- Vano, M.; Derchi, G.; Barone, A.; Genovesi, A.; Covani, U. Tooth bleaching with hydrogen peroxide and nano-hydroxyapatite: A 9-month follow-up randomized clinical trial. Int. J. Dent. Hyg. 2015, 13, 301–307. [Google Scholar] [CrossRef]
- Browning, W.D.; Cho, S.D.; Deschepper, E.J. Effect of a nano-hydroxyapatite paste on bleaching-related tooth sensitivity. J. Esthet. Restor. Dent. 2012, 24, 268–276. [Google Scholar] [CrossRef]
- Hiller, K.-A.; Buchalla, W.; Grillmeier, I.; Neubauer, C.; Schmalz, G. In vitro effects of hydroxyapatite containing toothpastes on dentin permeability after multiple applications and ageing. Sci. Rep. 2018, 8, 4888. [Google Scholar] [CrossRef]
- Hu, M.L.; Zheng, G.; Zhang, Y.D.; Yan, X.; Li, X.C.; Lin, H. Effect of desensitizing toothpastes on dentine hypersensitivity: A systematic review and meta-analysis. J. Dent. 2018, 75, 12–21. [Google Scholar] [CrossRef]
- Meyer, F.; Fabritius, H.-O.; Enax, J. Spezielle Zahnpflege bei Dentinhypersensibilität. ZMK 2017, 33, 865–868. [Google Scholar]
- Haywood, V.B.; Cordero, R.; Wright, K.; Gendreau, L.; Rupp, R.; Kotler, M.; Littlejohn, S.; Fabyanski, J.; Smith, S. Brushing with a potassium nitrate dentifrice to reduce bleaching sensitivity. J. Clin. Dent. 2005, 16, 17–22. [Google Scholar]
- Martin, J.; Fernandez, E.; Bahamondes, V.; Werner, A.; Elphick, K.; Oliveira, O.B., Jr.; Moncada, G. Dentin hypersensitivity after teeth bleaching with in-office systems. Randomized clinical trial. Am. J. Dent. 2013, 26, 10–14. [Google Scholar]
- Wuelknitz, P. Cleaning power and abrasivity of European toothpastes. Adv. Dent. Res. 1997, 11, 576–579. [Google Scholar] [CrossRef]
- Dinc Ata, G.; Gokay, O.; Mujdeci, A.; Kivrak, T.C.; Mokhtari Tavana, A. Effect of various teas on color stability of resin composites. Am. J. Dent. 2017, 30, 323–328. [Google Scholar]
- Arocha, M.A.; Mayoral, J.R.; Lefever, D.; Mercade, M.; Basilio, J.; Roig, M. Color stability of siloranes versus methacrylate-based composites after immersion in staining solutions. Clin. Oral Investig. 2013, 17, 1481–1487. [Google Scholar] [CrossRef]
- Zhao, X.; Zanetti, F.; Majeed, S.; Pan, J.; Malmstrom, H.; Peitsch, M.C.; Hoeng, J.; Ren, Y. Effects of cigarette smoking on color stability of dental resin composites. Am. J. Dent. 2017, 30, 316–322. [Google Scholar]
- Heimer, S.; Schmidlin, P.R.; Stawarczyk, B. Discoloration of PMMA, composite, and PEEK. Clin. Oral Investig. 2017, 21, 1191–1200. [Google Scholar] [CrossRef]
Whitening Agent | Mode of Action |
---|---|
Abrasives (e.g., hydrated silica, perlite, alumina) → Most important toothpaste ingredient for stain removal | Mechanical removal of extrinsic stains |
Antiredeposition agents (e.g., polyphosphates, sodium citrate) | Prevention of the deposition of chromophores and inhibition of calculus formation where external stains could be incorporated |
Calcium phosphates (e.g., hydroxyapatite) | Adhesion of white calcium phosphate particles on the tooth surface, and prevention of bacterial attachment/plaque-formation on the teeth |
Colorants (e.g., blue covarine) | Shifting color absorption and reflection spectra from yellow to blue |
Enzymes/proteases (e.g., papain, bromelain) | Support stain removal due to degradation of proteins (hydrolysis of peptide bonds) |
Peroxides (e.g., hydrogen peroxide, calcium peroxide) | Oxidation of organic chromophores |
Polyaspartate (e.g., sodium polyaspartate) | Inhibition of plaque-formation |
Surfactants (e.g., sodium lauryl sulfate) | Removal of hydrophobic compounds from the tooth surface |
Name (INCI) | Chemical Formula | Relative Hardness | Expected Stain Removal |
---|---|---|---|
Sodium bicarbonate | NaHCO3 | Soft | Low |
Dicalcium phosphate dihydrate (brushite) | CaHPO4 ∙ 2 H2O | Soft | Low |
Calcium carbonate | CaCO3 | Soft | Low |
Calcium pyrophosphate | Ca2P2O7 | Medium hard | Medium |
Hydroxyapatite | Ca5(PO4)3(OH) | Medium hard | Medium |
Hydrated silica | SiO2 ∙ n H2O | Medium hard | Medium |
Perlite | A mineral silicate | Hard | High |
Alumina | Al2O3 | Hard | High |
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Epple, M.; Meyer, F.; Enax, J. A Critical Review of Modern Concepts for Teeth Whitening. Dent. J. 2019, 7, 79. https://doi.org/10.3390/dj7030079
Epple M, Meyer F, Enax J. A Critical Review of Modern Concepts for Teeth Whitening. Dentistry Journal. 2019; 7(3):79. https://doi.org/10.3390/dj7030079
Chicago/Turabian StyleEpple, Matthias, Frederic Meyer, and Joachim Enax. 2019. "A Critical Review of Modern Concepts for Teeth Whitening" Dentistry Journal 7, no. 3: 79. https://doi.org/10.3390/dj7030079