Periodontal disease is one of the two major dental diseases that affect human populations worldwide at high prevalence rates.459,460 Periodontal diseases constitute one of the major global oral health burdens and periodontitis remains a major cause of tooth loss in adults worldwide. The World Health Organization recently reported that severe periodontitis exists in 5-20% of adult populations.461
A recent University of Southern California research study462 indicates that having periodontal disease before age 35 increases the risk of developing Alzheimer‘s disease in later life.
Periodontal disease is associated with bone loss around the alveolar bone (housing the teeth) and tooth loss. It is present in 90% of individuals over the
454 D. J. Thompson, P. H. Phillips, Journal of Dental Research. 45, 845 (1966). 455 D. Triers, C.G. Elliott, M.D. Smith, J. K. Dent. Res. 47, 1171 (1968).
456 Krishnamachari K. A. V. R, and Laxmaiah N., Lack of effect of massive dose of vitamin C on fluoride excretion in fluorosis during a short clinical trial,
The American Journal of Clinical Nutrition 28: November 1975, pp. 1234-1236. 457 Pandit, C. G., I. N. S. Raghavachari, D. S. Rao And V. Krishnamurthy. Endemic fluorosis in South India. A study of the factors involved in the production of mottled anamel in children and severe bone manifestations in adults. Indian J. Med. Res. 28: 559, 1940.
458 Suttie JW, Phillips PH: Fluoride ingestion and vitamin metabolism. In Fluorine and Dental Health: the Pharmacology and Toxicology of Fluorine. JC Muhler and MK Hine eds. BloomingtonI, N: Indiana University Press, 1959, pp 70-77.
459 Petersen PE. The World Oral Health Report 2003: Continuous improvement of oral health in the 21st century - The approach of the WHO Global Oral Health Programme. Community Dent Oral Epidemiol 2003;31(Suppl. 1):3-24.
460 Papapanou PN. Epidemiology of periodontal diseases: An update. J Int Acad Periodontol 1999;1:110-116.
461 Jin LJ, Armitage GC, Klinge B, Lang NP, Tonetti M, Williams RC. Global oral health inequalities: task group--periodontal disease. Adv Dent Res. 2011 May;23(2):221-6. 462 Gatz M, Mortimer J A, Fratiglioni L, Johansson B, Berg S, Reynolds C A, Pedersen N L. Potentially modifiable risk factors for dementia in identical twins , Alzheimer's & Dementia: The Journal of the Alzheimer's Association Volume 2, Issue 2 , Pages 110- 117, April 2006
age of 65. It has been reported that the potential mechanisms by which host factors may influence onset and progression of periodontal disease directly or indirectly include underlying low bone density in the oral cavity, bone loss, genetic susceptibility and exposure to risk factors. 463
It has been reported that fluoride decreases cortical bone mineral density and increases skeletal fragility.464,465 Further studies by Philips et al.466 reported a negative association between drinking fluoridated water and cortical bone mass and concluded that “increased fluoride may in fact be detrimental to cortical bone mass." Consequently, as the jaw bone is composed of cortical bone, it is evident that exposure to fluoride may be considered a risk factor for the onset of periodontal disease.
It is alarming therefore that the European Food Safety Authority (EFSA) has stated that an infant‘s retention of fluoride in bone can be as high as 90% of the absorbed amount.467
Several studies have shown that osteoporosis is also associated with jaw bone quality, bone density,468 the condition of the inferior mandibular cortex,469470 and the alveolar bone condition.471 There is increasing evidence also that osteoporosis, and the underlying loss of bone mass characteristic of this disease, is associated with periodontal disease and tooth loss. Current evidence, including several prospective studies, supports an association of osteoporosis with the onset and progression of periodontal disease in humans. 472 Systemic loss of bone density in osteoporosis, including that of the oral cavity, may provide a host system that is increasingly susceptible to infectious
463 Wactawski-Wende J. Periodontal diseases and osteoporosis: association and mechanisms. Ann Periodontol. 2001 Dec;6(1):197-208.
464 Riggs BL, et al. (1990). Effect of Fluoride treatment on the Fracture Rates in Postmenopausal Women with Osteoporosis. New England Journal of Medicine. 322:802-809.
465 Sogaard CH, et al. (1995). Effects of fluoride on rat vertebral body biomechanical competence and bone mass. Bone. 16(1): 163-9.
466 Phipps KR, Burt BA. (1990). Water-borne fluoride and cortical bone mass: A comparison of two communities. Journal of Dental Research 69: 1256-1260.
467 Opinion of the Scientific Panel on Dietetic Products, Nutrition and Allergies on a request from the Commission related to the Tolerable Upper Intake Level of Fluoride. The EFSA Journal (2005) 192, 1-65
468 Jacobs R, Ghyselen J, Koninckx P, van Steenberghe D. Long-term bone mass evaluation of mandible and lumbar spine in a group of women receiving hormone replacement therapy. Eur J Oral Sci 1996; 104:10-16.
469 Lee K, Taguchi A, Ishii K, Suei Y, Fujita M, et al. Visual assessment of the mandibular cortex on panoramic radiographs to identify postmenopausal women with low bone mineral densities. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2005;100:226-31 470 Nishida M, Grossi SG, Dunford RG, Ho AW, Trevisan M. Calcium and the risk for periodontal disease. J Periodontol 2000; 71:1057-66.
471 Taguchi A, Tsuda M, Ohtsuka M, Kodama I, Sanada M, et al. Use of dental panoramic radiographs in identifying younger postmenopausal women with osteoporosis. Osteoporosis Int 2006; 17:387-94.
472 Wactawski-Wende J. Periodontal diseases and osteoporosis: association and mechanisms. Ann Periodontol. 2001 Dec;6(1):197-208.
destruction of periodontal tissue.473 Both periodontal disease and osteoporosis are serious public-health concerns. The association between fluoride and osteoporosis is well documented. Understanding the association between fluoride exposure and bone quality and the mechanisms underlying those associations is critically important to prevent, diagnose and treat these very common diseases.
It is accepted that at least 50% of ingested fluoride is taken up by bone, and that fluoridation of water can increase normal dietary intake by about 50%.474 It is known that fluoride affects bone in at least two ways—fluoride ions can replace hydroxyl ions in the hydroxyapatite lattice, and increased fluoride concentrations in plasma directly increase osteoblastic differentiation and activity. Such changes could have an important effect on risk of fracture.475 The Hillier et al.476 epidemiological study examining fluoride in drinking water found that patients exposed to fluoridated water had increased amounts of fluoride in the cortical bone, supporting not only the importance of water fluoride in interfering with bone metabolism, but fluoridation of water to osteoporosis and periodontal disease. It is notable that the link between fluoride exposure and weakening bone strength was also accepted by the USA Scientific Committee of the National Research Council477.
Other direct and indirect associations which exist, that increase the risk or probability of developing periodontal disease, include Vitamin C deficiency and diabetes. The relationship between fluoride exposure and both Vitamin C deficiency and diabetes is also well-documented providing further strength of association between fluoride exposure and periodontal disease. The WHO reported that severe Vitamin C deficiency may result in aggravated periodontal disease conditions.478
473 Wactawski-Wende J. Periodontal diseases and osteoporosis: association and mechanisms. Ann Periodontol. 2001 Dec;6(1):197-208.
474 Whitford GM. The metabolism and toxicity of fluoride. Basel: Karger, 1996: 1–141 475 Hillier S, Cooper C, Kellingray S, Russell G, Hughes H, Coggon D, Fluoride in drinking water & risk of hip fracture in the UK: a case-control study, Lancet 2000; 355: 265–69. 476 Hillier S, Cooper C, Kellingray S, Russell G, Hughes H, Coggon D, Fluoride in drinking water & risk of hip fracture in the UK: a case-control study, Lancet 2000; 355: 265–69. 477 National Research Council. (2006). Fluoride in Drinking Water: A Scientific Review of EPA's Standards. National Academies Press, Washington D.C. p. 146.
478 Petersen E P. Ogawa H., Strengthening the Prevention of Periodontal Disease: The WHO Approach, Global Oral Health Program, World Health Organization, Geneva, Switzerland, J Periodontol • December 2005
As fluoride has been demonstrated to effect bone health and density negatively, it is plausable therefore to assume that exposure to fluoride through ingesting fluoridated water or foods is therefore likely to increase the associated risk of developing periodontal disease.
In regard to diabetes, it is widely documented that subjects with diabetes mellitus have a higher risk of periodontal disease, and indeed periodontal disease has been considered the sixth complication of diabetes.479,480
Extensive studies have reported significant associations between diabetes and severity of periodontal disease.481,482 Taylor et al.483 concluded from a literature review of severe periodontal disease and diabetes mellitus that not only was there a greater prevalence of periodontal symptoms amongst diabetics but that the progression of periodontal disease was also more aggressive or rapid.