How to cite this paper: Spielman, AI. History of Periodontics. In: Illustrated Encyclopedia of the History of Dentistry, 2023.

Periodontal disease has existed for at least 100,000 years (1) and possibly as far back as 3 million years (2). Unlike caries, a diet-associated bacterial disease, periodontal disease is a local irritant- and bacteria-induced inflammatory response of the host leading to the destruction of the dental supporting structures. Unlike caries which progressively increased in humans as carbohydrate and soft consistency diet became available during human evolution, irritants and recession of alveolar crest are quite common in primates and would have been expected in hominids (3) long before agriculture and civilization influenced the nature of the human diet. However, moderate to severe periodontal disease prevalence is not consistently increased. Among a Romano-British population from the 200-400 CE period, the rate appears to be low at around 10%. (4)  

During human evolution, in the last 14,000 years, there is evidence of early manipulation on the occlusal surface or exposed root canals to avoid food impaction and/or reduce sensitivity. The earliest evidence dealing with the consequences of advanced periodontal disease, such as tooth mobility, comes from 3-4c BCE for tightening loose teeth using gold wire. Such gold wire ligatures appear to be Egyptian from the Ptolemaic period, Greek, Phoenician, or Roman (5,6). In some instances, they  anchor replacement teeth lost to periodontal destruction.

One of the key early documents referring to periodontal disease is the Ebers Papyrus, acquired in 1873 and dating from the 18th century BCE. It includes 870 remedies, several for gingivitis and periodontitis. Treatment includes cow’s milk, fresh dates and uah grain, kept moist and chewed nine times (7); the image on the right, Ebers Papyrus from National Library of Medicine, Found in Egypt in the 1870s, the Ebers Papyrus contains prescriptions written in hieroglyphics for over seven hundred remedies, the image in Public Domain). In the Indian subcontinent, two founders of Ayurvedic medicine, Charaka and Sushrata (7th-6th BCE), compiled medical, herbal, and surgical texts to deal with various ailments, including periodontal disease. The Sanskrit Sushrata was translated into English in 1911 and provided recipes for conditions when “the gums of the teeth suddenly bleed and become putrified, slimy and emit fetid odor”(8). The condition that causes bleeding gums is called “paridara”. Explained through a “humoral theory” similar to the one proposed by Hippocrates, the treatment first required purging the patient “both ways by means of emetics and purgatives”. In addition, the gums had to be covered with a mixture of five official kinds of salts in honey and Trikatu, a mixture of pippali, ginger, and black pepper.

Figure. A segment of the Ebers Papyrus.

The early first millennium BCE Chinese text, Nei Ching (The Yellow Emperor’s Textbook of Medicine), recommends treatment for necrotizing gingivitis ((Ya-heou), chronic destructive periodontal disease (Ja-suen), or herpetic stomatitis (Tcheuen-ya-kan). In many instances, acupuncture was recommended (9).       

With most of the literature from antiquity reprinted, what we know from Arab translations is what 10th-century scholars deemed worthy of translating and practicing. The literature from Roman times is the first to discuss inflammation. Aulus Cornelius Celsus (25 BCE- 50 CE), a Roman physician and author of De Re Medicina, described the four cardinal signs of inflammation: tumor, rubor, calor, and dolor (swelling, redness, heat, and pain (10). Albucasis (Abu-l-Qasim, 936-1013), an eminent Islamic scholar, published  Kitab al-Tsarif, a 30-volume  self-contained encyclopedia that synthesized Greco-Roman knowledge and that of Islamic medicine. A whole section is dedicated to dental and periodontal problems. Like Rhazes, another Islamic scholar (865-923?) used cauterization of the gums with hot red arsenic and calcium boiled in vinegar inserted with a protective funnel to treat gum disease (11). Albucasis understood the relationship between calculus and periodontitis. He developed a set of scalers to remove calculus and used silver wire to ligate loose teeth to each other (12).

During the Renaissance, a more conservative intervention for gingival swelling was proposed by Leonello Vittori (1450-1520), who suggested a topical ointment of chicken fat (adipis gallinæ) or, chamomile oil mixed with honey (Olei chamomælini, mellis, ana unc. 1. misce bene ad inuicem agitando, et lineatur locus læfus… oleo de chamomilla sit sedatio doloris (13). Jacques Guillemeau (1550-1613), Ambroise Paré’s pupil and successor at Hotel Dieu in Paris, defines two conditions affecting the gum epulis, a partial inflammation of the gums (gingivarum partis aliquius inflammatio) and paroulis, an outgrowth next to some teeth (14). For the gingival putrefaction (putrefaction a la gencive) he recommends a touch of “blue water” (en peu d’eau bleue, dite eau de separation), a mixture of nitric and hydrochloric acid (15).  Although inconsequential at the time for the evolution of the periodontal disease, in 1683, Anthony van Leeuwenhoek (1632-1723), an amateur scientist, draper, part-time janitor, and early microscope enthusiast, identified oral spirochetes (16) as one of many “animalcules” in saliva. He collected his own “spittle” and “observed many small living animals…so small that…there might be many thousands in a quantity of water no larger than a sand”. The importance of any of these in disease had wait for 200 more years. 

One of the important milestones in dentistry was the publication of Francesco Martinez’s text in 1557 entitled Coloquio Breve, the first dedicated text to dentistry in Spanish. His scaling instruments are among his many innovations in this rare book (17). Similar instruments reappear in Ambroise Paré’s 1570 publication, Oeuvres, but in general, the 16 and 17th-century medical literature that has reserved a section for treating dental pain ignores the periodontal disease. When mentioned, like in this 1660 edition of Lazare Rivière, periodontal disease was due to “acrid humors (humoribus acribus) causing inflammation and ulcerations leading to scurvy” (18). An important concept in understanding periodontal disease was put forward in 1691 by Frederich Ruysch (1638-1731), a German physician. He made the link between tartar and periodontal disease (19). Martin Bernardin, the author of the first text on teeth in French (1687), claimed that periodontal tissue loss was due to an erosion of the humors and acrid vapors (“d’une erosion d’humeurs et d’une vapeur acre”), echoing the view of the prevalent view of the time (20). Pierre Fauchard (1678–1761), in turn, promoted the cause-effect relationship of calculus and periodontal disease, an idea he took from Hermann Boerhaave (1668-1738), a promoter of the iatromechanic concept on inflammation (21). Boerhaave published two important texts in 1708, Institutiones Medicae, and 1709, Aphorismi de Cognoscendis Et Curandis Morbis, both well before Fauchard’s 1728 publication of Le Chirurgien Dentist with a clear influence on his thinking.  Fauchard, probably due to his long exposure to naval voyages and experience with sailors suffering from scurvy,   described marginal periodontitis as a “kind of scurvy”, a systemic condition, but subsequently, as his clinical experience grew, he identified it as a local problem due to negligence and three factors, food entrapment, air drying of the deposits on the tooth surface as we breathe, and saliva.(22) As a remedy he suggests cleaning with instruments(23) and for the patient, strict oral hygiene.

Figure. Ligation of loose teeth from 1471 edition of Albucasis (Abu-l-Qasim) Kitab al-Tsarif – The Method of Medicine.

Etienne Bourdet, the most important dentist of the 18th century after Fauchard, in 1757, links gingival pocket to periodontal bone loss and suggests a reduction of the excess gingiva using a cautery with a hot iron, a crude form of gingivectomy (24).  A less traumatic approach is suggested by  Edme Francois Julien Botot in his 1770 article entirely dedicated to periodontal disease (25). Unlike Etienne Bourdet, instead of cauterization, he suggests removing calculus, oral flushing, and applying camphor oil to the gingiva.

In 1806, Joseph Fox, a London dentist, published an important work, The History and Treatment of the Diseases of the Teeth, the Gums and the Alveolar Processes with the Operations they Respectively Require. He dedicates six sections of his book to describe diseases of the gum and a separate section to the scaling of the teeth.  He calls periodontal disease “absorption of the sockets” (26). Despite such advances, treating gingival inflammation with “rebalancing of the humors” is still found in the work of Chapin R. Harris, one of the founders of modern dental education in America (27). For inflamed gums, he suggested the placement of 2-3 leeches on the gum.

Chapin Harris recommending leeches for inflamed gingiva..

In the early 19th century Jacob Berzelius, the Swedish chemist, determined the composition of dental calculus to be 79 parts earthly phosphates, 12.5 parts salivary mucus, 1 part ptyalin (amylase), and 7.5 animal matter soluble in hydrochloric acid (28). The connection of saliva to calculus formation and the consistency of salivary stones and calculus were already made by Pierre Fauchard (29). That accumulation of salivary calculus on tooth surfaces was detrimental to the health of the gum, and periodontium was becoming obvious. John Tomes, of London, in 1859, suggested to maintain health, one has to do “careful daily brushing”…” but should an accumulation take place it must be removed by instruments fitted for the purpose” (30).

The symptoms and management of what we call today chronic periodontal disease appeared in a carefully worded, but at the time, very much ignored work (31). Leonard Koecker described in great detail the symptoms and, with limitations of its period, the management of chronic periodontal disease. Very few dentists believed him or took up his treatment. One dentist that believed him was John W. Riggs, Mark Twain’s dentist. The periodontal disease had many names, including “Riggs disease”,pyorrhea alveolaris,”  or “chronic suppurative pericementitis”, coined after John W. Riggs (1811-1885), a Connecticut dentist who specialized in treating this condition. Incidentally, Riggs was present when Horace Wells tested laughing gas for tooth extraction, and he was the dentist who pulled Well’s tooth.

The microbial connection between the presence of pathogens and periodontal inflammation was probably one of the most important discoveries in the history of this disease. In 1804, John Greenwood of New York, dentist to George Washington, made side notes in a text he owned, the Natural History of the Human Teeth, by John Hunter. Greenwood did not publish his observations. That volume was donated to the New York Academy of Medicine, and in 2023, the side notes, which describe “annamalcula and tartar accumulation” for the first time, were published. (32.) In 1847, Robert Ficinus, a physician from Dresden, observed pathogens in the fibers between the gingiva and cement and recalled Leeuwenhoek’s observations 160 years prior (33). His description and naming of the Denticola species(34) set the stage for other oral microbiological discoveries during the second part of the 19th century. The most prominent oral microbiologist of the 19th century was Willoughby Miller, a Michigan graduate of physics and math and a University of Pennsylvania graduate of DDS. His studies extended into cariology, endodontics, and periodontics, specialties that did not yet exist. In 1890 he published the first oral microbiology text entitled The Microorganisms of the Human Mouth (35). That same year, having completed his thesis with Robert Koch on the chemo-parasitic nature of caries, Miller considered the etiology and contributing factors of periodontal disease. His observations concluded that local irritants, calculus (tartar), food debris, and unfavorable hygienic conditions are all contributing factors and that multiple bacteria, not one specific, were part of the cause, the nonspecific plaque hypothesis.

At the end of the 19th century, two discoveries furthered our understanding of periodontal disease: the description of dental plaque by  J Leon Williams (36). Williams’ description of the plaque was in the context of understanding acid production, but the plaque provided a basic understanding of how plaque can contribute to gingivitis and periodontitis. The second innovation was gingivectomy, the surgical technique developed by Salomon Robicsek (1845-1928), a Hungarian-born, Viennese dentist (37), modified and coined “gingivectomy” in 1912 by Henry Percy Pikerill, a stomatologist from New Zealand (38). A large number of surgical improvements have been adopted over the years, including those of GV Black (1836-1915) from Chicago, Robert Neumann (1882-1958) of Berlin, and Leonard Widman (1871-19586 of Sweden. The interventions were meant to remove excess and necrotic soft and hard tissue, provide a refreshed surface for healing and regeneration, and reduce retentive areas where plaque accumulation could occur.

In the early 20th century, two centers of excellence in periodontal study stand out: Vienna and Berlin. Leo Fleischmann (1871-1932), Bernhard Gottlieb (1885-1950), and later Balint Orban (1899-1960) undertook a systematic microbiological and histological analysis of the periodontal pocket advancing the bacterial and chronic nature of the disease. To this, the Berlin school brought illustrious contributors like Oskar Weski (1879-1952).  Over the latter part of the 20th century, surgical interventions to remove necrotic tissue have been replaced by regenerative techniques that included attempts at bone graft or root surface remineralization. Another technique, guided tissue regeneration, introduced in 1982, proved particularly promising (39).

Throughout the 20th Century, further stratification on the clinical manifestation of the disease affecting the periodontal tissue gradually occurred, separating acute from chronic and marginal periodontitis from periodontosis was defined.  These definitions led to two camps for treatment of the periodontal pocket: surgical vs. scaling and local cleaning. 

In 1965 Harold Loe designed a study to “attempt to produce gingivitis in patients with healthy gingivae by withdrawing all active efforts directed toward oral cleanliness, and to study the sequence of changes in the microbial flora and in the gingivae thus produced.” (40). It was the first direct evidence of a cause-effect relationship.

As a better understanding of periodontal disease emerged, efforts to provide non-surgical interventions emerged. In 1987, Larry Golub and his group introduced low-dose tetracycline (doxycyclines, or LDD). LDD is an anti-microbial agent at high doses and anti-inflammatory at low doses. The anti-inflammatory effect is achieved via a calcium-binding mechanism and a specific matrix metalloproteinase (MMP-8) inhibition.  A series of studies by Axelsson started in 1970 on prevention in oral health demonstrated that comprehensive plaque control for 6, 15, and 30 years can prevent both periodontal disease and caries (41).

Management of periodontal disease over the millennia has dramatically changed. From benign neglect to hot iron cauterization to surgical removal to prevention and tissue regeneration, the field is evolving and is establishing a systemic connection, a link that should have been apparent for a long time. 

Periodontics has evolved from the field of general dentists or surgeons to a specialty. Established for the first time in the US in 1947, today, it is a universally accepted specialty worldwide.

  • 1. Virchow
  • 2. Ripamonti (a) (b)1
  • 3. Miles p.529
  • 4. Raitapuro-Murray
  • 5. Clawson
  • 6. Becker
  • 7. Bryan p.112
  • 8. Bhishagratna p.102, p.464
  • 9. Shklar and Chernin p.52
  • 10. Celsus p.139
  • 11. Hoffmann p.94
  • 12. Albucasis p.177
  • 13. Vittori p.10
  • 14. Guillemeau p.185
  • 15. Ibid p.684
  • 16. Leeuwenhoek p.568-9
  • 17. Martinez
  • 18. Rivière p.375
  • 19. Ruysch p.104
  • 20. Martin p.130
  • 21. Seiler
  • 22. Fauchard 2d Vol I. p.177
  • 23. Ibid 2d ed. Vol II. p.15
  • 24. Bourdet p.288
  • 25. Botot
  • 26. Fox p.88
  • 27. Harris, p.170
  • 28. Simon p.473
  • 29. Fauchard p.179
  • 30. Tomes p.538
  • 31. Koecker p. 270
  • 32. Spielman
  • 33. Ficinus p.1-44
  • 34. Ibid p.8
  • 35. Miller
  • 36. Williams
  • 37. Stern
  • 38. Pickerill p.66
  • 39. Nyman
  • 40. Loe
  • 41. Axelson (a)., (b). (c).

References and notes on periodontology

Albucasis (al-Zahrāwī, Abū ʻl-Qāsim) (1532). Chirurgicorum Libri Tres. Strassbourg,  p.173-175 – description of dental forceps and surgical instruments; p.177 – use of silver ligature to enhance loose teeth). This volume is combined with the work of Priscianus, Theodorus, and Neuenra, Hermann von (1532). Rerum Medicarum Libri Quator. Argent Apud Ioannem Schottum.

Armitage, Gary C. (2020). A Brief history of periodontics in the United States of America: Pioneers and thought-leaders of the past, and current challenges. Periodontology 2000. 82:12-25. (History of periodontics)

Axelsson P, Lindhe J. (1981) (a). Effect of controlled oral hygiene procedures on caries and periodontal disease in adults – results after 6-years. J Clin Periodontol 8:239-48. 

Axelsson P,Lindhe J, Nyström B. (1991) (b). On the prevention of caries and periodontal disease. Results of a 15-year longitudinal study in adults. J Clin Periodontol 13:182-9.

Axelsson P, Nyström B,Lindhe J. (2004) (c). The long term effect of a plaque control program on tooth mortality, caries and periodontal disease in adults: Results after 30 years of maintenance. J Clin Periodontol 31:740-57.

Becker, Marshall J (1997). Early dental appliances in Eastern Mediterranean. Berytus 42:71-102. (Egyptian, Greek, Roman wiring of loose mandibular teeth).

Bishagratna, Kinjalal (1911). An English Translation of the Sushruta Samhita, Vol 2. p.102 and p. 464 (Definition of gingivitis – paridara – and its treatment).

Botot, E.F. Julien (1770). Observationes, sur la suppuration des gencives. Journal de Medicine, Chirurgie, Pharmacie. Vol 32, January, p 356-372. [archiveorg s3id13654830 width=560 height=384 frameborder=0 webkitallowfullscreen=true mozallowfullscreen=true]

Bourdet, Etienne (1757). Recherches et observations sur toutes les parties de l’art du dentiste, Vol I, p 288. 1757. (hot iron cautery of inflammed gingiva to reduce pocket, a form of gingivectomy.)

Bryan, Cyril Phillips (1930). Ancient Egyptian Medicine – The Papyrus Ebers (Translated from the German by Bryan, Cyril Phillips). Chicago, Ares Publishers Inc., 1930, p.112 (

Celsus, Cornelius Aurelius (1688). De Medicina Libri Octo, Apud Joannem Wolters, Amstelædami, Chapter X, pp. 139, §10. (Notæ vero inflammationis sunt quatuor, rubor & tumor, cum calore et dolore – Signs of inflammation are four, redness and swelling with heat and pain. (signs of inflammation)

Clawson, MD (1933). A Phoenician dental appliance of the 5th Century B.C. Transactions of the American Dental Society of Europe: 142-160. (wire ligature of mobile lower incisors).

Fauchard, Pierre (1746). Le Chirurgien Dentiste. 2d Ed. Vol I, p.177. (Cause of gingival inflammation is neglect, local accummulation of calculus, p.179 – connection of salivary stones and calculus). Vol II, Planche IX.  p.15. (Calculus removal instruments).

Ficinus, Robert (1847). Uber des Ausfallen der Zahne und das Wesen der Zahnkaries, p.1-43. (Observation of pathogens in fibers between the cement and gingiva)

Fox, Joseph (1806).  The history and treatment of the diseases of the teeth, the gums and the alveolar processes. p.88, (Calls periodontal disease, “absorption of the gums”).

Guillemeau, Jacque (1612). Les Oeuvres de chirurgie de Jacques Guillemeau. p.186 and 684. Paris, Chez Nicolas Buon. (defining epoulis and paroulis, p186 and treating gingival putrefaction with nitric/hydrochloric acid, p.684).

Kinane, D., Stathopoulou, P. & Papapanou, P. (2017). Periodontal diseases. Nat Rev Dis Primers 3, 17038. (General reference).

Koecker, Leonard (1826). Of the devastation or absorption of the gums and sockets on the teeth. IN: Principles of Dental Surgery. London, p 270-299.,+1826&printsec=frontcover

Leewenhoeck A v. (1684). An abstract of a letter from Mr. Anthony Leewenhoeck at Delft, dated Sep. 17. 1683 containing some microscopical observations, about animals in the scurf of the teeth, the substance call’d worms in the nose, the cuticula consisting of scales. Philosophical Transactions: The Royal Society Publishing. 1684;14:568–574. Illustration of first spirochets from a human mouth.)

Löe H, Theiladt: E, Jensen SB (1965).  Experimental gingivitis in man.  J  Periodontol 36:177-187. (Correlation between plaque and periodontal disease proven)

Löe, Harald (1993). Periodontal disease: A brief historical perspective. Periodontology 2000. 2:7-12. (History of periodontics).

Mandl, M (1843). Microscopical researches concerning the composition of “tartar” and the mucous deposits on the tongue and teeth.  The London Physiological Society, 1(1):30. (first to notice bacteria in tartar, similar to Leeuwenhoek). Originally published in French, Recherche microscopique sur la composition du tartre et des enduits muqueux de la langue et des dents, par M.L. Mandl. on July 3, Compte Rendu des Seances de L’Academie des Sciences – Memoires et communicationes. 16(2):213-214. (in French, or

Martin, Bernardin (1679). Dissertation sur les Dents. Chez Denys Thierry, Paris. p.130.  (a humoral theory as for the cause of periodontal disease).

Martinez, Francisco (1557). Coloquio Breve y compendioso. Sobre la materia de la dentadura. Valladolid. (First Spanish text on dentistry. (Scaling instruments).

Miles, AEW and Grigson, Carolyn (1936). Colyer’s Variations and diseases of the teeth in animals. p.529. (Periodontitis in animals).

Miller, Willoughby, D. (1890). The microorganisms of the human mouth. Philadelphia, p.333. (Suggested to irrigate periodontal pocket with disinfectant solution,

Nyman S, Lindhe J, Karring T, Rylander H. (1982). New attachment following surgical treatment of human periodontal disease. J Clin Periodontol  9: 290-296. (Guided tissue regeneration)

Pickerill, Henry Percy (1912). Stomatology in general practice: A textbook of diseases of the teeth and mouth for students and practitioners. (modified gingivectomy of Robicsek and naming it as such).

Raitapuro-Murray T, Molleson TI and Hughes FJ (2014). The prevalence of periodontal disease in a Romano-British population c. 200-400 AD. Brit D. J. 217(8): 459-466. (Low prevalence of moderate to severe periodontal disease among 2d-4th c. individuals).

Ripamonti, Ugo (1988)(a). Paleopathology in  Australopithecus  africanus:  A  Suggested  Case  of a 3-Million-Year-Old Prepubertal Periodontitis. Am. J. Phys. Anthropol. 76:197-210. (3 million year old juvenile periodontitis).

Ripamonti, Ugo (1989)(b). The Hard Evidence of Alveolar Bone Loss in Early Hominids of Southern Africa

A Short Communication. J. Periodontol. 60(2): 118-120.

Rivière, Lazare (1660). Praxis Medica. Cap. III De gingivarum erosione et exculceratione. p.375. Ioannis Antonii Huguetan, Lugduni. (periodontal disease caused by acrid humor – humoribus acribus).

Ruysch, Frederich (1691). Observationum anatomico-chirurgicum, centuria – Observatio LXXXII., p. 104.  ( (affirmed the relationship between tartar and periodontal disease).

Seiler, Roger, Galassi, Francesco M.; Ruhli, Frank (2017). Fauchard, Boerhaave and the Pathogenesis of Periodontitis in the 17th and 18th Centuries. European Journal Of Oral Sciences 125(3). DOI: 10.1111/eos.12344 (review of Boerhaave influencing Fauchard in his views on periodontal disease)

Shklar, Gerald and Chernin, David (2001). A sourcebook of dental medicine. p. 52 (Chinese medicine, Nei Ching recommends treatment for various periodontal disease using acupuncture).

Simon, Franz (1846). Animal Chemistry. Physiology and Pathology of Man. p.473. (Berzelius’ compositional analysis of calculus – phosphate 79, mucin 12.5, ptyalin 1, organic matter 7.5)

Spielman AI, Koshki J, Lepor A, Shaner, A (2023). John Greenwood’s side-notes on a 1778 John Hunter text at New York Academy of Medicine. J Hist Dent. In press.

Stern, Irvin g B, Everett, Frank G, Robicsek, Karl (1965). S Robicsek – A pioneer in the surgical treatment of periodontal disease. J Periodontol. 36:265-268. (Robicsek, the developer of the surgical technique later called gingivectomy).

Tomes, John (1859). A system of dental surgery.  Tartar or salivary calculus. p.535-539. John Churchill, London. (removal of calculus and composition of salivary stone and calculus by Berzelius).

Underwood, AS and Miles WT (1881). An investigation into the effects of organisms upon the teeth and alveolar portions of the jaw. Transactions of the International Medical Congress, 1881 London. Vol 3. p.523-527. (Demonstration of the chemo-parasitic theory in 1881, 17 years before Willoughby Miller).

Vittori, Faventini Leonello Benedicti (1557). De Eadem Tractione Appendicula – Georgium Kuffnerium. Cap. I, p.10 – Practica – On gingival swellings – apply an ointment  made up of one ounce of “adipis gallinæ” apply onto the gingiva. Or: Chamomile oil and honey, each, one ounce, mix it well by shaking and place it on the wound. (Olei chamomælini, Mellis, ana unc. 1. Misce bene ad inuicem agitando, et lineatur locus læfus… oleo de camomilla sit sedatio doloris. (for gingival swelling)

Virchow, Hans, (1915). Unterkiefer von Ehringsdorf. Zeitschrift Ethnologie 47: 444-449.). and Virchow, H. (1920). Die menschlichen Skelettreste aus dem Kampfe’schen Bruch im Travertin von Ehringsdorf bei Weimar. Jena. (Periodontal disease 100.000 years ago).

Williams, J. Leon (1897). A contribution to the study of the pathology of enamel. Dental Cosmos. 39(4):269-301 and 39(5):353-374. (The presence of a plaque on tooth surface p.296)

2023 © Copyright