Editing Tooth decay (section)

==Cause==
[[File:Dental caries etiology diagram.png|thumb|Diagrammatic representation of acidogenic theory of causation of dental caries. Four factors, namely, a suitable carbohydrate substrate '''(1)''', micro-organisms in dental plaque '''(2)''', a susceptible tooth surface '''(3)''' and time '''(4)'''; must be present together for dental caries to occur '''(5)'''. Saliva '''(6)''' and fluoride '''(7)''' are modifying factors.]]
Four things are required for caries to form: a tooth surface (enamel or dentin), caries-causing bacteria, fermentable [[carbohydrate]]s (such as [[sucrose]]), and time.<ref>{{cite book |vauthors=Southam JC, Soames JV |chapter=2. Dental Caries |title=Oral pathology |publisher=Oxford Univ. Press |location=Oxford |year=1993 |isbn=978-0-19-262214-3 |edition=2nd}}</ref> This involves [[Adhesion|adherence]] of food to the teeth and [[acid]] creation by the bacteria that makes up the [[dental plaque]].<ref>{{Cite journal|last1=Wong|first1=Allen|last2=Young|first2=Douglas A.|last3=Emmanouil|first3=Dimitris E.|last4=Wong|first4=Lynne M.|last5=Waters|first5=Ashley R.|last6=Booth|first6=Mark T.|date=2013-06-01|title=Raisins and oral health|journal=Journal of Food Science|volume=78|issue=Suppl 1 |pages=A26–29|doi=10.1111/1750-3841.12152|issn=1750-3841|pmid=23789933|doi-access=free}}</ref> However, these four criteria are not always enough to cause the disease and a sheltered environment promoting development of a cariogenic biofilm is required. The caries disease process does not have an inevitable outcome, and different individuals will be susceptible to different degrees depending on the shape of their teeth, [[oral hygiene]] habits, and the [[buffering capacity]] of their saliva. Dental caries can occur on any surface of a tooth that is exposed to the oral cavity, but not the structures that are retained within the bone.<ref>{{cite book |vauthors=Smith B, Pickard HM, Kidd EA |chapter=1. Why restore teeth?|title=Pickard's manual of operative dentistry |publisher=Oxford University Press |year=1990 |isbn=978-0-19-261808-5 |edition=6th}}</ref>

Tooth decay is caused by [[biofilm]] (dental plaque) lying on the teeth and maturing to become cariogenic (causing decay). Certain bacteria in the biofilm produce acids, primarily [[lactic acid]], in the presence of [[fermentation (food)|fermentable]] carbohydrates such as [[sucrose]], [[fructose]], and [[glucose]].<ref name="Soro 2024">{{cite book |vauthors=Soro SA, Lamont RJ, Egland PG, Koo H, Liu Y |title=Molecular Medical Microbiology |chapter=Chapter 44-Dental caries | publisher=Elsevier | year=2024 |isbn=978-0-12-818619-0 |doi=10.1016/b978-0-12-818619-0.00036-8 |pages=915–930}}</ref><ref name="Hardie1982">{{cite journal |author=Hardie JM |title=The microbiology of dental caries |journal=Dental Update|volume=9 |issue=4 |pages=199–200, 202–4, 206–8 |date=May 1982 |pmid=6959931 }}</ref><ref name="holloway1983">{{cite journal |author=Holloway PJ |title=The role of sugar in the etiology of dental caries |journal=Journal of Dentistry|volume=11 |issue=3 |pages=189–213 |date=September 1983 |doi=10.1016/0300-5712(83)90182-3 |last2=Moore |first2=W.J. |pmid=6358295}}</ref>

Caries occur more often in people from the lower end of the socio-economic scale than people from the upper end of the socio-economic scale, due to lack of education about dental care, and lack of access to professional dental care which may be expensive.<ref>Watt RG, Listl S, Peres MA, Heilmann A, editors. [http://nebula.wsimg.com/604637088cabf4db588c57f1fc1d8029?AccessKeyId=72A54FA9729E02B94516&disposition=0&alloworigin=1 Social inequalities in oral health: from evidence to action] {{webarchive|url=https://web.archive.org/web/20150619131928/http://nebula.wsimg.com/604637088cabf4db588c57f1fc1d8029?AccessKeyId=72A54FA9729E02B94516&disposition=0&alloworigin=1 |date=2015-06-19 }}. London: International Centre for Oral Health Inequalities Research & Policy; www.icohirp.com</ref>

===Bacteria===
[[File:Streptococcus mutans 01.jpg|right|thumb|alt=Refer to caption|A [[Gram stain]] image of ''Streptococcus mutans'']]{{See also|Oral ecology}}
The most common bacteria associated with dental cavities are the mutans streptococci, most prominently ''[[Streptococcus mutans]]'' and ''[[Streptococcus sobrinus]]'', and [[Lactobacillus|lactobacilli]]. However, cariogenic bacteria (the ones that can cause the disease) are present in dental plaque, but they are usually in too low concentrations to cause problems unless there is a shift in the balance.<ref>{{Cite journal|last1=Marsh|first1=Philip D.|last2=Head|first2=David A.|last3=Devine|first3=Deirdre A.|year=2015|title=Dental plaque as a biofilm and a microbial community—Implications for treatment|url=https://www.sciencedirect.com/science/article/abs/pii/S1349007915001073|journal=Journal of Oral Biosciences|volume=57|issue=4|pages=185–191|doi=10.1016/j.job.2015.08.002|s2cid=86407760|archive-url=https://web.archive.org/web/20210829091308/https://www.sciencedirect.com/science/article/abs/pii/S1349007915001073|archive-date=29 August 2021}} [http://eprints.whiterose.ac.uk/88879/ Alt URL] {{Webarchive|url=https://web.archive.org/web/20210508033258/https://eprints.whiterose.ac.uk/88879/ |date=2021-05-08 }}</ref> This is driven by local environmental change, such as frequent sugar intake or inadequate biofilm removal (toothbrushing).<ref>{{Cite journal|last=Marsh|first=P|year=1994|title=Microbial ecology of dental plaque and its significance in health and disease|journal=Advances in Dental Research|volume=8|issue=2|pages=263–71|doi=10.1177/08959374940080022001|pmid=7865085|s2cid=32327358}}</ref> If left untreated, the [[disease]] can lead to pain, [[tooth loss]] and [[infection]].<ref>[http://www.mayoclinic.com/health/cavities/DS00896/DSECTION=7 Cavities/tooth decay] {{webarchive|url=https://web.archive.org/web/20080315144137/http://www.mayoclinic.com/health/cavities/DS00896/DSECTION%3D7 |date=2008-03-15 }}, hosted on the Mayo Clinic website. Page accessed May 25, 2008.</ref>

The mouth contains a wide variety of [[oral ecology|oral bacteria]], but only a few specific species of bacteria are believed to cause dental caries: ''Streptococcus mutans'' and ''Lactobacillus'' [[species]] among them. ''Streptococcus mutans'' are gram-positive bacteria which constitute biofilms on the surface of teeth. These organisms can produce high levels of lactic acid following [[fermentation]] of dietary sugars and are resistant to the adverse effects of low pH, properties essential for cariogenic bacteria.<ref name="Hardie1982"/> As the [[cementum]] of root surfaces is more easily demineralized than enamel surfaces, a wider variety of bacteria can cause root caries, including ''[[Lactobacillus acidophilus]]'', ''[[Actinomyces|Actinomyces spp.]]'', ''[[Nocardia spp.]]'', and ''Streptococcus mutans''. Bacteria collect around the teeth and gums in a sticky, creamy-coloured mass called [[dental plaque|plaque]], which serves as a [[biofilm]]. Some sites collect plaque more commonly than others, for example, sites with a low rate of salivary flow (molar fissures). Grooves on the [[Occlusion (dentistry)|occlusal]] surfaces of [[molar (tooth)|molar]] and [[premolar]] teeth provide microscopic retention sites for plaque bacteria, as do the interproximal sites. Plaque may also collect above or below the [[gingiva]], where it is referred to as supra- or sub-gingival plaque, respectively.

These bacterial strains, most notably ''S. mutans'', can be inherited by a child from a caretaker's [[kiss]] or through feeding [[premastication|pre-masticated]] food.<ref>{{citation |journal=Pediatric Dentistry|date=Sep–Oct 2008 |volume=30 |number=5 |pages=375–87 |title=Association of mutans streptococci between caregivers and their children |last1=Douglass |first1=JM |last2=Li |first2=Y |last3=Tinanoff |first3=N.|pmid=18942596 }}</ref>

===Dietary sugars===
Bacteria in a person's mouth convert glucose, fructose, and most commonly sucrose (table sugar) into acids, mainly lactic acid, through a [[glycolytic]] process called fermentation.<ref name="Soro 2024"/><ref name="holloway1983"/> If left in contact with the tooth, these acids may cause demineralization, which is the dissolution of its mineral content. The process is dynamic, however, as [[Remineralisation of teeth|remineralization]] can also occur if the acid is [[Neutralization (chemistry)|neutralized]] by saliva or [[mouthwash]]. Fluoride toothpaste or dental varnish may aid remineralization.<ref>{{cite journal |author=Silverstone LM |title=Remineralization and enamel caries: new concepts |journal=Dental Update|volume=10 |issue=4 |pages=261–73 |date=May 1983 |pmid=6578983 }}</ref> If demineralization continues over time, enough mineral content may be lost so that the soft [[organic compound|organic]] material left behind disintegrates, forming a cavity or hole. The impact such sugars have on the progress of dental caries is called cariogenicity. Sucrose, although a bound glucose and fructose unit, is in fact more cariogenic than a mixture of equal parts of glucose and fructose. This is due to the bacteria using the energy in the saccharide bond between the glucose and fructose subunits. ''S.mutans'' adheres to the biofilm on the tooth by converting sucrose into an extremely adhesive substance called [[dextran]] polysaccharide by the enzyme dextran sucranase.<ref>Madigan M.T. & Martinko J.M. Brock&nbsp;– ''Biology of Microorganisms''. 11th Ed., 2006, Pearson, USA. pp. 705</ref>

===Exposure===
[[File:Stephan curve.png|thumb|"Stephan curve", showing sudden decrease in plaque pH following glucose rinse, which returns to normal after 30–60&nbsp;min. Net demineralization of dental hard tissues occurs below the critical pH (5.5), shown in yellow.]]
The frequency with which teeth are exposed to cariogenic (acidic) environments affects the likelihood of caries development.{{citation needed|date=February 2020}} After meals or [[snack food|snack]]s, the bacteria in the mouth [[Metabolism|metabolize]] sugar, resulting in an acidic by-product that decreases pH. As time progresses, the pH returns to normal due to the buffering capacity of [[saliva]] and the dissolved mineral content of tooth surfaces. During every exposure to the acidic environment, portions of the inorganic mineral content at the surface of teeth dissolve and can remain dissolved for two hours.<ref>[http://www.dent.ucla.edu/ce/caries/ Dental Caries] {{webarchive|url=https://web.archive.org/web/20060630205712/http://www.dent.ucla.edu/ce/caries/ |date=2006-06-30 }}, hosted on the University of California Los Angeles School of Dentistry website. Page accessed August 14, 2006.</ref> Since teeth are vulnerable during these acidic periods, the development of dental caries relies heavily on the frequency of acid exposure.

The carious process can begin within days of a tooth's erupting into the mouth if the diet is sufficiently rich in suitable carbohydrates. Evidence suggests that the introduction of fluoride treatments has slowed the process.<ref name="summit75">Summit, James B., J. William Robbins, and Richard S. Schwartz. "[[iarchive:fundamentalsofop0002unse/page/75/mode/2up|Fundamentals of Operative Dentistry: A Contemporary Approach.]]" 2nd edition. Carol Stream, Illinois, Quintessence Publishing Co, Inc, 2001, p. 75. {{ISBN|0-86715-382-2}}.</ref> Proximal caries take an average of four years to pass through enamel in permanent teeth. Because the cementum enveloping the root surface is not nearly as durable as the enamel encasing the [[Crown (tooth)|crown]], root caries tend to progress much more rapidly than decay on other surfaces. The progression and loss of mineralization on the root surface is 2.5 times faster than caries in enamel. In very severe cases where oral hygiene is very poor and where the diet is very rich in fermentable carbohydrates, caries may cause cavities within months of tooth eruption. This can occur, for example, when children continuously drink sugary drinks from baby bottles (see later discussion).

===Teeth===
[[File:Blausen 0864 ToothDecay.svg|thumb|300px|Tooth decay]]

There are certain diseases and disorders affecting teeth that may leave an individual at a greater risk for cavities.

Molar incisor hypo-mineralization seems to be increasingly common.<ref name="MastRodrigueztapia2013">{{cite journal|vauthors=Mast P, Rodrigueztapia MT, Daeniker L, Krejci I|title=Understanding MIH: definition, epidemiology, differential diagnosis and new treatment guidelines|date=Sep 2013|journal=European Journal of Paediatric Dentistry|volume=14|issue=3|pages=204–8|url=http://admin.ejpd.eu/download/EJPD_2013_03_07.pdf|pmid=24295005|type=Review|url-status=live|archive-url=https://web.archive.org/web/20161005114609/http://admin.ejpd.eu/download/EJPD_2013_03_07.pdf|archive-date=2016-10-05}}</ref> While the cause is unknown it is thought to be a combination of genetic and environmental factors.<ref>{{Cite journal|last1=Silva|first1=Mihiri J.|last2=Scurrah|first2=Katrina J.|last3=Craig|first3=Jeffrey M.|last4=Manton|first4=David J.|last5=Kilpatrick|first5=Nicky|date=August 2016|title=Etiology of molar incisor hypomineralization&nbsp;— A systematic review|journal=Community Dentistry and Oral Epidemiology|volume=44|issue=4|pages=342–353|doi=10.1111/cdoe.12229|issn=1600-0528|pmid=27121068|hdl=11343/291225|hdl-access=free}}</ref> Possible contributing factors that have been investigated include systemic factors such as high levels of [[dioxins and dioxin-like compounds|dioxins]] or [[polychlorinated biphenyl]] (PCB) in the mother's milk, [[preterm birth|premature birth]] and oxygen deprivation at birth, and certain disorders during the child's first 3 years such as [[mumps]], [[diphtheria]], [[scarlet fever]], [[measles]], [[hypoparathyroidism]], [[malnutrition]], [[malabsorption]], [[hypovitaminosis D|hypo-vitaminosis D]], chronic [[respiratory disease]]s, or undiagnosed and untreated [[coeliac disease]], which usually presents with mild or absent gastrointestinal symptoms.<ref name=MastRodrigueztapia2013 /><ref>{{cite journal|vauthors=William V, Messer LB, Burrow MF|title=Molar incisor hypomineralization: review and recommendations for clinical management|year=2006|journal=Pediatric Dentistry|volume=28|issue=3|pages=224–32|url=http://www.aapd.org/assets/1/25/william2-28-3.pdf|pmid=16805354|type=Review|url-status=live|archive-url=https://web.archive.org/web/20160306130920/http://www.aapd.org/assets/1/25/william2-28-3.pdf|archive-date=2016-03-06}}</ref><ref>{{cite web|url=http://celiac.nih.gov/PDF/Dental_Enamel_Defects_508.pdf|title=Dental Enamel Defects and Celiac Disease|publisher=National Institute of Health (NIH)|access-date=Mar 7, 2016|quote=Tooth defects that result from celiac disease may resemble those caused by too much fluoride or a maternal or early childhood illness. Dentists mostly say it's from fluoride, that the mother took tetracycline, or that there was an illness early on|url-status=live|archive-url=https://web.archive.org/web/20160305124250/http://celiac.nih.gov/PDF/Dental_Enamel_Defects_508.pdf|archive-date=2016-03-05}}</ref><ref>{{cite journal|vauthors=Ferraz EG, Campos Ede J, Sarmento VA, Silva LR|title=The oral manifestations of celiac disease: information for the pediatric dentist|year=2012|journal=Pediatric Dentistry|volume=34|issue=7|pages=485–8|pmid=23265166|type=Review|quote=The presence of these clinical features in children may signal the need for early investigation of possible celiac disease, especially in asymptomatic cases. (...) Pediatric dentists must recognize typical oral lesions, especially those associated with nutritional deficiencies, and should suspect the presence of celiac disease, which can change the disease's course and patient's prognosis.}}</ref><ref>{{cite journal|vauthors=Rashid M, Zarkadas M, Anca A, Limeback H|title=Oral manifestations of celiac disease: a clinical guide for dentists|year=2011|journal=Journal of the Canadian Dental Association|volume=77|page=b39|url=http://www.jcda.ca/article/b39|pmid=21507289|type=Review|url-status=live|archive-url=https://web.archive.org/web/20160308090224/http://www.jcda.ca/article/b39|archive-date=2016-03-08}}</ref><ref>{{cite journal|vauthors=Giuca MR, Cei G, Gigli F, Gandini P|title=Oral signs in the diagnosis of celiac disease: review of the literature|year=2010|journal=Minerva Stomatologica|volume=59|issue=1–2|pages=33–43|pmid=20212408|type=Review}}</ref>

[[Amelogenesis imperfecta]], which occurs in between 1 in 718 and 1 in 14,000 individuals, is a disease in which the enamel does not fully form or forms in insufficient amounts and can fall off a tooth.<ref name="neville89">Neville, B.W., Damm, Douglas; Allen, Carl and Bouquot, Jerry (2002). "''Oral & Maxillofacial Pathology.''" 2nd edition, p. 89. {{ISBN|0-7216-9003-3}}.</ref> In both cases, teeth may be left more vulnerable to decay because the enamel is not able to protect the tooth.<ref name="neville94">Neville, B.W., Damm, Douglas; Allen, Carl and Bouquot, Jerry (2002). "''Oral & Maxillofacial Pathology.''" 2nd edition, p. 94. {{ISBN|0-7216-9003-3}}.</ref>

In most people, disorders or diseases affecting teeth are not the primary cause of dental caries. Approximately 96% of tooth enamel is composed of minerals.<ref>[[#Nanci|Nanci]], p. 122</ref> These minerals, especially [[hydroxyapatite]], will become soluble when exposed to acidic environments. Enamel begins to demineralize at a pH of 5.5.<ref>{{cite journal |author=Dawes C |title=What is the critical pH and why does a tooth dissolve in acid? |journal=Journal of the Canadian Dental Association|volume=69 |issue=11 |pages=722–4 |date=December 2003 |pmid=14653937 |url=http://www.cda-adc.ca/jcda/vol-69/issue-11/722.html |url-status=live |archive-url=https://web.archive.org/web/20090714130336/http://www.cda-adc.ca/jcda/vol-69/issue-11/722.html |archive-date=2009-07-14 }}</ref> Dentin and cementum are more susceptible to caries than [[Tooth enamel|enamel]] because they have lower mineral content.<ref>{{cite journal |author=Mellberg JR |title=Demineralization and remineralization of root surface caries |journal=Gerodontology|volume=5 |issue= 1|pages=25–31 |year=1986 |doi=10.1111/j.1741-2358.1986.tb00380.x |pmid=3549537}}</ref> Thus, when root surfaces of teeth are exposed from gingival recession or periodontal disease, caries can develop more readily. Even in a healthy oral environment, however, the tooth is susceptible to dental caries.

The evidence for linking [[malocclusion]] and/or crowding to dental caries is weak;<ref>{{cite journal |doi=10.3109/00016357.2010.516732 |author1=Borzabadi-Farahani, A |author2=Eslamipour, F |author3=Asgari, I |title=Association between orthodontic treatment need and caries experience |journal=Acta Odontologica Scandinavica|volume=69 |pages=2–11 |year=2011 |pmid=20923258|issue=1 |s2cid=25095059 }}</ref><ref>{{cite journal | pmid =22999666| year = 2012 | title = Dental crowding as a caries risk factor: A systematic review | journal = American Journal of Orthodontics and Dentofacial Orthopedics| volume = 142 | issue = 4| pages = 443–50 | doi = 10.1016/j.ajodo.2012.04.018 | last1 = Hafez | first1 = HS | last2 = Shaarawy | first2 = SM | last3 = Al-Sakiti | first3 = AA | last4 = Mostafa | first4 = YA}}</ref> however, the anatomy of teeth may affect the likelihood of caries formation. Where the deep developmental grooves of teeth are more numerous and exaggerated, pit and fissure caries is more likely to develop (see next section). Also, caries is more likely to develop when food is trapped between teeth.

===Other factors===
Reduced salivary flow rate is associated with increased caries since the buffering capability of saliva is not present to counterbalance the acidic environment created by certain foods. As a result, medical conditions that reduce the amount of saliva produced by [[salivary gland]]s, in particular the [[submandibular gland]] and [[parotid gland]], are likely to lead to [[xerostomia|dry mouth]] and thus to widespread tooth decay. Examples include [[Sjögren syndrome]], [[diabetes mellitus]], [[diabetes insipidus]], and [[sarcoidosis]].<ref name="neville398">Neville, B. W., Douglas Damm, Carl Allen, Jerry Bouquot. ''Oral & Maxillofacial Pathology'' 2nd edition, 2002, p. 398. {{ISBN|0-7216-9003-3}}.</ref> Medications, such as antihistamines and antidepressants, can also impair salivary flow. Stimulants, most notoriously [[methylamphetamine]], also occlude the flow of saliva to an extreme degree. This is known as [[meth mouth]]. [[Tetrahydrocannabinol]] (THC), the active chemical substance in [[cannabis (drug)|cannabis]], also causes a nearly complete occlusion of salivation, known in colloquial terms as "cotton mouth". Moreover, 63% of the most commonly prescribed medications in the United States list dry mouth as a known side-effect.<ref name="neville398"/> Radiation therapy of the head and neck may also damage the [[cell (biology)|cell]]s in salivary glands, somewhat increasing the likelihood of caries formation.<ref>[http://www.cancer.gov/cancertopics/pdq/supportivecare/oralcomplications/Patient/page5 Oral Complications of Chemotherapy and Head/Neck Radiation] {{webarchive|url=https://web.archive.org/web/20081206081959/http://www.cancer.gov/cancertopics/pdq/supportivecare/oralcomplications/Patient/page5 |date=2008-12-06 }}, hosted on the [http://www.cancer.gov/ National Cancer Institute] {{webarchive|url=https://web.archive.org/web/20150312111454/http://www.cancer.gov/ |date=2015-03-12 }} website. Page accessed January 8, 2007.</ref><ref>See Common effects of cancer therapies on salivary glands at {{cite web |url=http://ebd.ada.org/SystematicReviewSummaryPage.aspx?srId=66bffb53-0043-4892-a8ab-f0cfe2231928 |title=ADA&nbsp;— EBD::Systematic Reviews |access-date=2013-07-30 |url-status=dead |archive-url=https://web.archive.org/web/20131202230733/http://ebd.ada.org/SystematicReviewSummaryPage.aspx?srId=66bffb53-0043-4892-a8ab-f0cfe2231928 |archive-date=2013-12-02 }}</ref>

Susceptibility to caries can be related to altered metabolism in the tooth, in particular to fluid flow in the dentin. Experiments on rats have shown that a high-sucrose, cariogenic diet "significantly suppresses the rate of fluid motion" in dentin.<ref>Ralph R. Steinman & John Leonora (1971) "Relationship of fluid transport through dentation to the incidence of dental caries", ''[[Journal of Dental Research]]'' 50(6): 1536 to 43</ref>

The use of [[tobacco]] may also increase the risk for caries formation. Some brands of [[dipping tobacco|smokeless tobacco]] contain high sugar content, increasing susceptibility to caries.<ref name="neville347">Neville, B.W., Douglas Damm, Carl Allen, Jerry Bouquot. ''Oral & Maxillofacial Pathology'' 2nd edition, 2002, p. 347. {{ISBN|0-7216-9003-3}}.</ref> Tobacco use is a significant risk factor for periodontal disease, which can cause the [[gingiva]] to [[receding gums|recede]].<ref>[http://www.perio.org/consumer/smoking.htm Tobacco Use Increases the Risk of Gum Disease] {{webarchive|url=https://web.archive.org/web/20070109123411/http://www.perio.org/consumer/smoking.htm |date=2007-01-09 }}, hosted on the [http://www.perio.org/index.html American Academy of Periodontology] {{webarchive|url=https://web.archive.org/web/20051214140958/http://www.perio.org/index.html |date=2005-12-14 }}. Page accessed January 9, 2007.</ref> As the gingiva loses attachment to the teeth due to gingival recession, the root surface becomes more visible in the mouth. If this occurs, root caries is a concern since the cementum covering the roots of teeth is more easily demineralized by acids than enamel.<ref>Banting, D. W. "[http://www.nidcr.nih.gov/NR/rdonlyres/5A4386A8-E750-43E9-8450-651F4789D09A/0/David_Banting.pdf The Diagnosis of Root Caries] {{webarchive|url=https://web.archive.org/web/20060930192216/http://www.nidcr.nih.gov/NR/rdonlyres/5A4386A8-E750-43E9-8450-651F4789D09A/0/David_Banting.pdf |date=2006-09-30 }}." Presentation to the National Institute of Health Consensus Development Conference on Diagnosis and Management of Dental Caries Throughout Life, in pdf format, hosted on the National Institute of Dental and Craniofacial Research, p. 19. Page accessed August 15, 2006.</ref> Currently, there is not enough evidence to support a causal relationship between smoking and coronal caries, but evidence does suggest a relationship between smoking and root-surface caries.<ref>[https://www.cdc.gov/tobacco/sgr/sgr_2004/pdf/executivesummary.pdf Executive Summary] {{webarchive|url=https://web.archive.org/web/20070216060432/http://www.cdc.gov/TOBACCO/SGR/sgr_2004/pdf/executivesummary.pdf |date=2007-02-16 }} of U.S. Surgeon General's report titled, "The Health Consequences of Smoking: A Report of the Surgeon General," hosted on the [https://www.cdc.gov CDC] {{webarchive|url=https://web.archive.org/web/20120320214638/http://www.cdc.gov/ |date=2012-03-20 }} website, p. 12. Page accessed January 9, 2007.</ref>
Exposure of children to [[passive smoking|secondhand tobacco smoke]] is associated with tooth decay.<ref>{{cite journal|last1=Zhou|first1=S|last2=Rosenthal|first2=DG|last3=Sherman|first3=S|last4=Zelikoff|first4=J|last5=Gordon|first5=T|last6=Weitzman|first6=M|title=Physical, behavioral, and cognitive effects of prenatal tobacco and postnatal secondhand smoke exposure|journal=Current Problems in Pediatric and Adolescent Health Care|date=September 2014|volume=44|issue=8|pages=219–41|pmid=25106748|doi=10.1016/j.cppeds.2014.03.007|pmc=6876620}}</ref>

Intrauterine and neonatal [[lead]] exposure promote tooth decay.<ref>{{cite journal |doi=10.1177/00220345560350031401 |vauthors=Brudevold F, Steadman LT |title=The distribution of lead in human enamel |journal=Journal of Dental Research|volume=35 |pages=430–437 |year=1956 |pmid=13332147 |issue=3 |s2cid=5453470 }}</ref><ref>{{cite journal |doi=10.1177/00220345770560100701 |vauthors=Brudevold F, Aasenden R, Srinivasian BN, Bakhos Y |title=Lead in enamel and saliva, dental caries and the use of enamel biopsies for measuring past exposure to lead |journal=Journal of Dental Research|volume=56 |pages=1165–1171 |year=1977 |pmid=272374 |issue=10 |s2cid=37185511 }}</ref><ref>{{cite journal |author=Goyer RA |title=Transplacental transport of lead |journal=Environmental Health Perspectives|volume=89 | pages=101–105 |year=1990 |pmid=2088735 |doi=10.2307/3430905 |pmc=1567784 |jstor=3430905 }}</ref><ref>{{cite journal |vauthors=Moss ME, Lanphear BP, Auinger P |title=Association of dental caries and blood lead levels |journal=JAMA|volume=281 |issue=24 |pages=2294–8 |year=1999 |pmid=10386553 |doi=10.1001/jama.281.24.2294|doi-access=free }}</ref><ref>{{cite journal |vauthors=Campbell JR, Moss ME, Raubertas RF |title=The association between caries and childhood lead exposure |journal=Environmental Health Perspectives|volume=108 |pages=1099–1102 |year=2000 |pmid=11102303 |doi=10.2307/3434965 |issue=11 |pmc=1240169 |jstor=3434965 }}</ref><ref>{{cite journal |doi=10.1289/ehp.021100625 |vauthors=Gemmel A, Tavares M, Alperin S, Soncini J, Daniel D, Dunn J, Crawford S, Braveman N, Clarkson TW, McKinlay S, Bellinger DC |title=Blood Lead Level and Dental Caries in School-Age Children |journal=Environmental Health Perspectives|volume=110 |pages=A625–A630 |year=2002 |pmid=12361944 |issue=10 |pmc=1241049 }}</ref><ref>{{cite journal |vauthors=Billings RJ, Berkowitz RJ, Watson G |title=Teeth |journal=Pediatrics|volume=113 |issue=4 |pages=1120–1127 |year=2004 |doi=10.1542/peds.113.S3.1120 |pmid=15060208 }}</ref> Besides lead, all [[atoms]] with [[electrical charge]] and [[ionic radius]] similar to bivalent [[calcium]],<ref>{{cite journal |vauthors=Leroy N, Bres E |title=Structure and substitutions in fluorapatite |journal=European Cells and Materials|volume=2 |pages=36–48 |year=2001 |pmid=14562256 |doi=10.22203/eCM.v002a05 |doi-access=free }}</ref>
such as [[cadmium]], mimic the calcium [[ion]] and therefore exposure to them may promote tooth decay.<ref>{{cite journal |doi=10.1289/ehp.10947 |vauthors=Arora M, Weuve J, Schwartz J, Wright RO |title=Association of environmental cadmium exposure with pediatric dental caries |journal=Environmental Health Perspectives|volume=116 |issue=6 |pages=821–825 |year=2008 |pmid=18560540 |pmc=2430240|bibcode=2008EnvHP.116..821A }}</ref>

Poverty is also a significant social determinant for oral health.<ref>{{cite journal | author = Dye B | year = 2010 | title = Trends in Oral Health by Poverty Status as Measured by Healthy People 2010 Objectives | pmid=21121227 | journal = Public Health Reports| volume = 125 | issue = 6| pages = 817–30 | pmc=2966663| doi = 10.1177/003335491012500609 }}</ref> Dental caries have been linked with lower socio-economic status and can be considered a disease of poverty.<ref>{{cite journal |author1=Selwitz R. H. |author2=Ismail A. I. |author3=Pitts N. B. | year = 2007 | title = Dental caries | journal = The Lancet| volume = 369 | issue = 9555| pages = 51–59 | doi=10.1016/s0140-6736(07)60031-2 | pmid=17208642|s2cid=204616785 }}</ref>

Forms are available for risk assessment for caries when treating dental cases; this system using the evidence-based [[CAMBRA|Caries Management by Risk Assessment]] (CAMBRA).<ref>[https://web.archive.org/web/20150201181112/http://public.health.oregon.gov/PreventionWellness/oralhealth/FirstTooth/Documents/ADA-CAMBRA.pdf ADA Caries Risk Assessment Form Completion Instructions]. American Dental Association</ref> It is still unknown if the identification of high-risk individuals can lead to more effective long-term patient management that prevents caries initiation and arrests or reverses the progression of lesions.<ref>{{cite journal|author=Tellez, M., Gomez, J., Pretty, I., Ellwood, R., Ismail, A.|title=Evidence on existing caries risk assessment systems: are they predictive of future caries? |journal=Community Dentistry and Oral Epidemiology|volume=41 |issue=1 |pages=67–78 |pmid=22978796|year=2013 |doi=10.1111/cdoe.12003 }}</ref>

Saliva also contains [[iodine]] and [[Epidermal growth factor|EGF]]. EGF results effective in cellular proliferation, differentiation and survival.<ref>{{cite journal | author = Herbst RS | title = Review of epidermal growth factor receptor biology | journal = International Journal of Radiation Oncology, Biology, Physics| volume = 59 | issue = 2 Suppl | pages = 21–6 | year = 2004 | pmid = 15142631 | doi = 10.1016/j.ijrobp.2003.11.041 | doi-access = free }}</ref> Salivary EGF, which seems also regulated by dietary inorganic iodine, plays an important physiological role in the maintenance of oral (and gastro-oesophageal) tissue integrity, and, on the other hand, iodine is effective in prevention of dental caries and oral health.<ref>{{cite journal |vauthors=Venturi S, Venturi M | title = Iodine in evolution of salivary glands and in oral health | journal = Nutrition and Health| volume = 20 | issue = 2 | pages = 119–134 | year = 2009 | pmid = 19835108 | doi = 10.1177/026010600902000204 | s2cid = 25710052 }}</ref>