The Science of Dentistry January Edition 2022
Introduction Another new year has arrived. EPSA wishes you a happy, prosperous, and healthy New Year! 2022’s Science! Monthly starts with a very interesting and relevant topic about dentistry written by future dentists and current students of the European Dentistry Students’ Associations (EDSA). This edition covers diverse topics such as the function of fluoride and first aid for teething babies. It also provides great tips on how to keep your oral cavity healthy by giving oral hygiene instructions. And did you know about the diversified range of toothbrushes? Read further to find out! Enjoy your reading!
Yong Xin Cao Science Coordinator 2021/2022
The European Dental Students’ Association (EDSA) is a non-profit, non-political organization representing more than 70,000 dental students across the WHO European Region. EDSA was founded in November 1988 in Paris and aims to unite, support and represent students acting as their regional association. We are a platform for the formulation & exchange of students’ thoughts, proposals & innovations and to advance research, dental education, teaching methods and philosophy. We strive to give students a voice in the national and international forum, to create a globally connected student community and to develop strong stands related to the societal aspects of dentistry.
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Fluoride: An aid to prevention, or a precursor to ailment? For almost a century, the effects of fluoride on human dentition have been studied and applied in the fight against dental decay. The question remains: do we still need it? Dental caries, or dental decay, is a biofilm-induced disease influenced by diet1. The main aetiological factors determining the severity of it are: • Cariogenic bacteria; • Fermentable carbohydrates; • A susceptible toot hand host; • Time. The cariogenic bacteria and the fermentable carbohydrates are the main constituents of the plaque biofilm. The bacteria metabolise the carbohydrates, producing acid that then demineralises calcium hydroxyapatite, which is what the tooth tissue mostly consists of2. The progression of this process over time is what leads to the cavitation, and, ultimately, the destruction of the tooth. In 1950, the “21 Cities Study” was published3. A study that, unbeknownst to the authors, would serve as a precursor to one of the ten greatest public health achievements of the 20th century – community water fluoridation. This study observed the cariostatic effect of fluoride in multiple similar communities over the course of 4 years. Each observed population had a different concentration of fluoride in their water supplies. The study concluded that community water fluoridation was successful in significantly reducing the prevalence of caries in those communities. An optimal concentration of 1 part per million (ppm) was recommended from the results of the study. Fluoride has a multifactorial role in combating caries. Primarily, its three main functions are: • Promoting tooth remineralisation; • Reducing tooth demineralisation; • Inhibiting plaque bacteria.
Figure 1: Toothbrush and toothpaste Remineralisation is promoted by fluoride accelerating the formation of a new layer of enamel on a partially demineralised surface. The fluoride ion (F-) replaces the hydroxide ion (OH-) in calcium hydroxyapatite, forming calcium fluorapatite instead. The fluorapatite EPSA – European Pharmaceutical Students’ Association
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crystals are more resistant to acid attack than the hydroxyapatite ones. Consequently, demineralisation is reduced. Finally, F- ions inhibit enolase enzymes in plaque bacteria that play a significant role in the bacterial metabolism of carbohydrates to acid. The F- is taken up by bacterial cells in association with hydrogen ions (H+). Once dissociation occurs intracellularly, the H+ acidifies the bacterial cell, which also aids in bacterial inactivation. However, the use of fluoride does not necessarily come without detriment. Ingestion of excess fluoride has been linked to the development of dental fluorosis, as well as skeletal fluorosis, and fluoride toxicity. While the risks of dental fluorosis remain mostly aesthetic, both skeletal fluorosis and toxic levels of fluoride can lead to more severe, chronic symptoms6-9. The use of topical fluoride is safe, largely eliminating the risk of developing skeletal fluorosis or fluoride toxicity, which requires fluoride to be consumed systemically8. Additionally, the integration of controlled fluoride dosages into populations, such as through fluoridated toothpaste provision, continues to increase with time. This, alongside improved access to professional dental care, and generally healthier diets, has led to a reduced need for such a rigorous, non-autonomous and centralised approach to fluoridating many communities9. This reduced need has encouraged some governments to reduce the concentrations of their fluoridated water to below the originally recommended 1ppm10-12, while others have chosen to cease community water fluoridation altogether. Fluoride remains an integral component of promoting good oral health, but the method of administration must be based on local community needs and the most effective use of resources.
Written by: Neil Unnadkat, EDSA Vice President of External Affairs 2020-2021 EPSA – European Pharmaceutical Students’ Association
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Types of toothbrushes Tooth brushing is an essential component of oral hygiene, but how important is our choice of instrument? Toothbrushes are key facilitators of oral hygiene – used to clean the teeth and gums in conjunction with toothpaste. Although varied, all toothbrushes consist of two main components: a head of tightly clustered bristles, and a handle. The most readily available toothbrushes on the market are either manual or electric. Manual toothbrushes can come in many different shapes and sizes. Key distinguishing factors are size, design, length, hardness, and arrangement of bristles1. The size of the toothbrush head should ideally reach the farthest, most posterior teeth in the dental arch effectively. The head of the toothbrush is most commonly rectangular or diamondshaped and is usually covered with synthetic (nylon) bristles. Toothbrush bristles can be soft, medium, or hard. The bristle pattern can also differ, ranging from block pattern, wavy or V-shaped pattern, multilevel trim pattern, criss-cross pattern, and polishing cup-bristles. The design of the handle can be straight, contraangled, or flexible2. Electric toothbrushes perform oscillations or rotations of the bristles, driven by a motor. They are further classified according to the speed of their movement as standard powered toothbrushes, sonic or ultrasonic. Sonic toothbrushes produce a humming sound. An ultrasonic toothbrush uses a very high frequency of vibration referred to as ultrasound in order to remove plaque, food debris, and bacteria. The high frequency and low amplitude waves cause the bacterial chains found in dental plaque to break apart. This is achieved simply through the vibrations alone and can therefore work as far as 5 mm below the gumline. This mechanism allows the brush to clean each tooth individually by resting against its surface3.
Figure 2: Toothbrushes EPSA – European Pharmaceutical Students’ Association
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Ultrasonic and electric toothbrushes show significantly better plaque reduction compared to manual toothbrushes3. Moreover, they are easier to use for people with limited ability and seem to be more attractive for children. The optional features of electrical toothbrushes include a timer, display, pressure sensor, ultrasound indicator, bluetooth, cleaning mode. Pressure sensors are particularly important in preventing overly-vigorous brushing, the primary cause of tooth surface loss. Toothbrushes do not last forever. They should be replaced every few months or when their bristles are worn4.
Written by: Yolena Gesheva, EDSA Research Officer 2020-2021
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Oral hygiene instructions There are some things you need to know before you can master the art of brushing your teeth. Plaque is the main causative factor in the formation of dental decay and the development of inflammatory periodontal diseases. These may be prevented by an appropriate and effective oral hygiene regimen – conducted both by the dentist or hygienist at suitable recall intervals, and the individual themselves on a daily basis1. The optimal daily oral hygiene regimen includes the mechanical removal of the bacterial biofilm on soft and hard oral tissues by brushing with adequately fluoridated toothpaste and cleaning the interproximal areas through using specially designed interdental brushes or by flossing. Brushing for two minutes has been shown to achieve clinically significant plaque removal, and it is recommended to do so twice daily2. Moreover, the use of toothpaste containing fluoride enhances fluoride concentration levels in biofilm fluid and saliva and is associated with decreased risk of caries and remineralisation of teeth2. However, it is not only brushing time but also brushing technique that is critical in maximising brushing efficacy. The ideal brushing method is modified slightly if you happen to use an electric toothbrush, which may be the preferred approach. Here, you can start by brushing the back tooth of the bottom row of your teeth on either side. Hold the head of the brush at a 45-degree angle from the gum line. Then, while applying light pressure, move the toothbrush from one tooth to another, polishing each with the rotating-oscillating brush head. Then, you can switch to the back tooth of the top row of your teeth from either side and repeat, brushing one tooth at a time3.
Figure 3: Brushing teeth EPSA – European Pharmaceutical Students’ Association
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If you wear braces, carefully clean around the brackets and under the wires and pins. Brush the actual wires of your braces so they are free of any plaque, and there are suitable brushes you can use, such as single-tufted brushes. It is recommended to clean your teeth twice a day, with one of those times being the last thing before going to sleep at night. Your toothbrush should fit in your mouth and allow you to reach all areas easily. For cleaning the surfaces in-between your teeth, you may believe dental floss is the ideal solution. However, interdental brushes are much more effective, especially if there are larger gaps between your teeth, though the smallest sizes are designed to clean in-between teeth closely contacting one another. The brushes come in several different sizes and should fit snugly between the two teeth. Optimal oral hygiene practices demand time, dexterity, and motivation. Healthcare professionals play a critical role in the treatment of disease, but effective and beneficial habits at home are essential in preventing disease. Therefore, encouraging such habits is the backbone of health promotion in dentistry.
Written by: Yolena Gesheva, EDSA Research Officer 2020-2021
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First Aid for Teething Babies Teething is a difficult time for parents and children, but steps can be taken to make the process less painful for everyone concerned. Teething is a physiological process whereby a baby's first set of teeth emerges through the gums. Eruption of teeth does not appear to cause systemic symptoms such as diarrhoea, fever, rashes, seizures or bronchitis. The timing of eruption of the primary teeth often coincides with the age where babies start to crawl and explore their environment. During that phase, babies usually place various objects into their mouths. This behaviour leaves them prone to infections that may cause diarrhoea, which is regularly and mistakenly associated with teething. Illness occurring alongside teething should not be dismissed so that a serious systemic pathology is not overlooked1.
Figure 4: A child with a toothbrush There are non-pharmacological methods to manage teething discomfort, such as teething rings commercially available for infants to ‘gnaw’. Liquid-filled teething rings are chilled in the refrigerator, and chewing on them provides temporary pain relief. A rash is a sign of excessive salivation that runs onto the baby’ skin, and therefore saliva should be wiped away regularly2. When local measures fail to provide relief, there are a wide range of viable topical and systemic options. 1. Lidocaine based preparations and topical Benzocaine gel are rapidly absorbed through mucous membranes, giving prompt relief from pain. Anaesthetic gels should be applied with a clean finger or cotton bud and rubbed onto the gingiva around the erupting tooth2. 2. Some choline salicylate-based products provide a mild analgesic effect and reduce swelling. The link between aspirin and Reye’s syndrome is not relevant for non-aspirin salicylates. Frequent application onto the oral mucosa may result in chemical burns2. 3. Systemic analgesics such as acetaminophen and ibuprofen can reduce the pain caused by teething. It is important to use the correct dosage to prevent an overdose. A sugar-free paracetamol syrup is an ideal option2.
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Parents should be advised that some of the products are potentially harmful. An article by Monaghan (2019) noted that of 14 licensed teething products in the UK, six contained alcohol and two contained sucrose (sucrose being present in the homeopathic products). Frequent intake of sugar is the primary cause of tooth decay, and the enamel is particularly susceptible to decay before the teeth have fully maturated in the mouth. Only sugar-free medication should be taken during teething3. Alcohol is known to be harmful to the brain of children in utero, and experiments suggest that alcohol continues to impact brain development after birth. Possible developmental consequences of alcohol consumption imply that products with alcohol should be avoided3. Even a drug as widely available and regularly used as lidocaine has the potential to cause some unwanted effects. In the United States, there have been 22 serious adverse reactions, including deaths, associated with the lidocaine 2% solution. These events were associated with incorrect dosing or accidental ingestion. Lidocaine-containing teething products should only be available under the supervision of a pharmacist and should be strictly considered where other measures have not provided relief. It often goes without saying, but all of the drug preparations cited here should be stored well out of the reach of children3.
Written by: Ivana Ligusová, EDSA General Secretary 2020-2021, EDSA President 2021-2022
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References Fluoride: An aid to prevention, or a precursor to ailment? [1] Harris, R., Nicoll, A.D., Pine, C.M. and Adair, P.M. (2004). Risk factors for dental caries in young children: a systematic review of the literature. Community Dent Health, 21(1), pp.71–85. [2] Wong, A., Subar, P.E. and Young, D.A. (2017 a,b,c). Dental Caries: An Update on Dental Trends and Therapy. Advances in Pediatrics, 64(1), pp.307–330. [3] Dean, H.T., Jr., F.A.A., Jay, P. and Knutson, J.W. (1950a,b). Studies on Mass Control of Dental Caries through Fluoridation of the Public Water Supply. Public Health Reports (1896-1970), 65(43), p.1403. [4] CDC (2000). Achievements in Public Health, 1900-1999: Fluoridation of Drinking Water to Prevent Dental Caries. JAMA, 283(10), p.1283. [5] Featherstone, J.D.B. (1999). Prevention and reversal of dental caries: role of low level fluoride. Community Dentistry and Oral Epidemiology, 27(1), pp.31–40. [6] DenBesten, P. and Li, W. (2011). Chronic Fluoride Toxicity: Dental Fluorosis. Fluoride and the Oral Environment, [online] 22, pp.81–96. [7] Vieira, A.P.G.F., Mousny, M., Maia, R., Hancock, R., Everett, E.T. and Grynpas, M.D. (2005). Assessment of teeth as biomarkers for skeletal fluoride exposure. Osteoporosis International, 16(12), pp.1576–1582. [8] Krishnamachari, K. (1986). Skeletal fluorosis in humans: a review of recent progress in the understanding of the disease. Progress in Food & Nutrition Science, 10(3-4), pp.279–314. [9] Whitford, G.M. (2011). Acute toxicity of ingested fluoride. Monographs in Oral Science, [online] 22, pp.66–80. [10] Kanduti, D., Sterbenk, P. and Artnik (2016). Fluoride: a Review of Use and Effects on Health. Materia Socio Medica, [online] 28(2), p.133. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4851520/. [11] Petersen, P.E., Baez, R.J. and Lennon, M.A. (2012). Community-oriented Administration of Fluoride for the Prevention of Dental Caries. Advances in Dental Research, 24(1), pp.5–10.
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[12] Wong, H.M., McGrath, C. and King, N.M. (2014). Diffuse opacities in 12-year-old Hong Kong children - four cross-sectional surveys. Community Dentistry and Oral Epidemiology, 42(1), pp.61–69. [13] Petersen, P.E. and Ogawa, H. (2016). Prevention of dental caries through the use of fluoride – the WHO approach. Community Dental Health, 33(2), pp.66–68. [14] Whelton, H. and O’Mullane, D. (2012). Monitoring the effectiveness of water fluoridation in the Republic of Ireland. Journal of the Irish Dental Association, 58, p.6-8. Types of toothbrushes [1] "Oral Longevity," American Dental Association brochure (PDF), page 2 Archived 201011-19 at the Wayback Machine Retrieved June 12, 2008 [2] Carranza FA: Clinical periodontology: Saunders, 9th Edn: 651-654,2003 [3] Anas B, Meriem ElM, Abdelhadi M, Zahra LF, Hamza M (2018) A Single- Brushing Study to Compare Plaque Removal Efficacy of a Manual Toothbrush, an Electric Toothbrush and an Ultrasonic Toothbrush. J Oral Hyg Health 6: 249. DOI: 10.4172/2332-0702.1000249 [4] Rosema NA, Hennequin-Hoenderdos NL, Versteeg PA, et al. Plaque-removing efficacy of new and used manual toothbrushes--a professional brushing study. Int J Dent Hyg 2013;11(4):237-43. Oral hygiene instructions [1] Takenaka S, Ohsumi T, Noiri Y (November 2019). "Evidence-based strategy for dental biofilms: Current evidence of mouthwashes on dental biofilm and gingivitis". The Japanese Dental Science Review. 55 (1): 33–40. [2] Creeth JE, Gallagher A, Sowinski J, et al. The effect of brushing time and dentifrice on dental plaque removal in vivo. J Dent Hyg 2009;83(3):111-6. [3] American Dental Association. Mouth Healthy: Brushing Your Teeth. Accessed March 28, 2019. First Aid for Teething Babies [1] Signs and Symptoms of Primary Tooth Eruption: A Meta-analysis Carla Massignan, Mariane Cardoso, André Luís Porporatti, Secil Aydinoz, Graziela De Luca Canto, Luis Andre Mendonça Mezzomo, Michele Bolan Pediatrics Mar 2016, 137 (3) e20153501; DOI: 10.1542/peds.2015-3501
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[2] Sood, S., & Sood, M. (2010). Teething: myths and facts. The Journal of clinical pediatric dentistry, 35(1), 9–13. https://doi.org/10.17796/jcpd.35.1.u146773636772101 [3] Monaghan N. (2019). Teething products may be harmful to health. British dental journal, 227(6), 485–487. https://doi.org/10.1038/s41415-019-0715-7
References for pictures: Front page image: https://unsplash.com/photos/-m-4tYmtLlI by Caroline LM. Image 1: https://pixabay.com/photos/toothpaste-toothbrush-brush-teeth-3067569/ by Bru-nO Image 2: https://unsplash.com/photos/CsPCTYYxalw by Henrik Lagercrantz. Image 3: https://unsplash.com/photos/sgzJMbUQbYg by Diana Polekhina Image 4: https://pixabay.com/photos/tooth-brush-baby-child-toothbrush-4089859/ by Drwrenchdds
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