Periodontitis and Cavities
Updated: 02/15/2006

There are many good reasons to keep your teeth and gums healthy. Healthy teeth and gums not only look better, but they also promote better eating habits and nutrition. By contrast, unhealthy, inflamed gums are associated with various diseases, including coronary heart disease and an elevated risk for heart attack, while tooth loss is linked to malnutrition.

In a healthy mouth, the teeth are intact and anchored in pink, firm gums that do not bleed during brushing. A regular tooth care program should include flossing and brushing twice daily, as well as regular visits to the dentist for cleaning and examination.

Gum disease and tooth loss are especially common among the elderly. Some researchers believe that the malnutrition that afflicts older people may be in part due to poor dentition (the type, number, and arrangement of a set of teeth). In fact, some researchers believe that the short life span of early humans was related to tooth loss that caused starvation (Goodman AH 1989; Story R 1986).

The three most common problems in the oral cavity are dental caries (cavities) and the periodontal diseases gingivitis and periodontitis. These are caused by multiple factors, including plaque buildup, diet, oral hygiene, genetics, environment, and lifestyle factors. For more information on gingivitis, the most common dental disease, see the chapter titled Gingivitis . Dental caries and periodontitis are discussed in this chapter.

Cavities

Dental caries, or cavities, occur when microorganisms build up in deposits of dental plaque and ferment dietary sugars. The byproduct of this fermentation, lactic acid, lowers the pH at the junction of the plaque layer and tooth enamel, and eventually the enamel is eroded (Geddes DA 1991).

The layer of plaque in the mouth has recently been redefined as “biofilm” (Rudney JD 2000). Biofilm develops in a predictable pattern, whereby oral bacteria colonize areas of the gums and teeth, then spread and eventually link with other organisms in a cohesive film. This film can occur both above and below the gum line. If left intact, it may form a hard, mineralized mass called calculus (tartar) (Bernimoulin JP 2003). This is the hard, yellow substance that dentists scrape off with specialized equipment. Tartar contains masses of bacteria that produce lactic acid and promote tooth decay. Brushing and flossing alone cannot penetrate or remove the tartar.

One novel hypothesis for disrupting the creation of biofilm and preventing tartar involves oral vaccines that may protect the mouth against Streptococcus mutans ( S. mutans ), the bacteria most commonly responsible for dental cavities. Human studies have shown encouraging results with antibodies designed to suppress colonization of S. mutans in the biofilm (Michalek SM et al 2004).

The risk of developing cavities differs for each individual, based on factors such as oral hygiene, genetics, the size and shape of the teeth, resistance to infection, retention of dental plaque, and metabolism of sugar (Boraas J et al 1988; Conry J et al 1993). In addition, people with pre-existing conditions such as gum disease have a greater chance of developing cavities, and smoking can accelerate the transformation of plaque into tartar (Feldman R et al 1983). Other risk factors for dental cavities include exposure to lead (Watson G et al 1997), polychlorinated biphenyls (PCBs) (Rogan W et al 1988), and second-hand smoke (Aligne C et al 2003).

Clinically, cavities appear as blemishes on the tooth surface. If they are not clinically visible, they can still be detected using dental x-rays. Most dentists recommend one set of dental x-rays annually.

Waiting for tooth pain as a reason to visit the dentist is a not a good strategy for preventing cavities. In many cases, cavities are not painful because they affect only the surface layers of the tooth and do not extend into the dental pulp, which is the soft tissue inside the tooth. In more advanced cases, a cavity may extend into the pulp, causing intense pain and pulp disease known as pulpitis. Early pulpitis is generally treatable. If it is not treated, however, it can advance to pulp death. At this point, the tooth may stop hurting because the nerve has died. By the time a cavity has reached this stage, the tooth will most likely require extraction. Modern preventive dentistry is designed to prevent tooth decay from reaching such advanced stages.

Fluoride: Effective Against Cavities

Fluoride's role in preventing cavities has been extensively documented (Klein H 1972). Teeth with adequate fluoride are resistant to acid, and studies have shown a 30 percent to 50 percent reduction in decay following the fluoridation of drinking water (Neenan E et al 2004).

The use of fluoride, however, is not without its side effects. The most common side effect is known as fluorosis. This permanent alteration causes small, barely visible white flecks on adult teeth (Dean H 1934). It occurs early during tooth development, when adult teeth are just coming in (Den Besten P 1999). To help prevent it, experts recommend:

1. Use of low-fluoride water in infant formulas
2. Adult supervision of children during brushing
3. Rigid application standards when administering fluoride supplements to children (Fomon S et al 2000).

There is, however, little question that fluoride works to prevent cavities. When children between the ages of five and six were treated with a 1.2 percent fluoride gel versus a placebo gel twice daily, the fluoride group showed a 40 percent decrease in cavities compared to the placebo group after a two-year follow-up (Klein H 1972).

Periodontitis

Periodontal diseases, including gingivitis and periodontitis, are inflammatory diseases that affect the supporting structures that anchor the teeth in place (periodontium). Gingivitis and periodontitis are related conditions: if left untreated, gingivitis, or inflammation of the gingival tissue (gums), can progress to periodontitis, a more serious condition. Gingivitis is a treatable and reversible condition, while periodontitis is an irreversible condition that can lead to tooth loss.

Risk factors for periodontitis include smoking, stress, depression (Grossi S 2000), and alcohol consumption (Tezal M et al 2004). Tobacco use is an important risk factor for periodontitis (Albandar JM et al 2000; Bergstrom J et al 2000a,b; Tomar S et al 2000). For more specific information on risk factors for gingivitis, the most common form of gum disease, see the chapter titled Gingivitis .

During periodontitis, the healthy gum tissue is transformed from pink and firm, with knife-edge margins between the soft tissue and the tooth, to inflamed and red. Eventually, the tissue pulls away from the tooth, allowing pockets to form. These pockets can be measured with a special probe during a standard dental check-up. Any pocket over 3 millimeters in depth signifies gingivitis; a pocket over 5 millimeters usually signifies periodontitis.

Periodontal infections frequently involve bacteria that discharge hydrogen sulfide, ammonia, amines, toxins, and inflammation-causing enzymes that can cause loss of tissue and teeth (Haffajee A et al 2000). Bleeding gums, bad breath, and pain also occur (Haffajee A et al 2000). Clinically, periodontitis is characterized by inflamed, red gums and deepening pockets between the tooth root and the gum tissue, as well as loss of bone in the jaw. Advanced periodontal disease can be diagnosed by changes in appearance of the teeth and gums, including:

1. noticeable loosening of the teeth
2. gum recession with the tooth root exposed
3. new spaces forming between the teeth
4. food being trapped between teeth and where gums have receded
5. constant bad taste in the mouth.

Periodontal disease is usually painless until late in the disease process, when the teeth are so loose that pain occurs while chewing. Retention of food in a pocket site may provoke a sudden burst of bacterial growth, resulting in a painful abscess (Loesche W et al 2001). At other times, the front teeth may become so loose that they separate.

Conventional therapy for periodontal disease consists of mechanical scaling and root planing, surgical treatment, and the use of various antimicrobial regimens (Loesche W et al 2001). The goal is to reduce the number of bacteria on the surface of the teeth by reducing the amount of plaque. If pocket depths in the gums are 5 millimeters or greater, large numbers of bacteria can accumulate that cannot be reached by normal oral hygiene. Periodontal surgery may then be recommended to reduce the pocket depths to 1 millimeter to 2 millimeters (Loesche W et al 2001).

Antibiotic therapy is sometimes needed when the bacterial count continues to climb. In open clinical trials, tetracycline has been used successfully to treat aggressive periodontitis, either as an oral tetracycline/surgery combination (Lindhe J et al 1984; Mandell R et al 1986, 1988) or alone for three to eight weeks (Christersson L et al 1993; Slots J et al 1983). T etracycline can deplete calcium, magnesium, and iron, so people on tetracycline should also use a multivitamin (Pelton R et al 2001).

There are several ways to release medications directly into the periodontal pocket, including the use of long-lasting gels. These methods reduce the dose of medicine needed and deliver the antibiotic in a highly targeted fashion (Loesche W et al 2001). Devices that deliver localized antibiotics are about as effective as systemic agents in their ability to target harmful bacteria, and they are advantageous in that people do not have to remember to take the medicine, thus improving patient adherence (Loesche W 1993, 1999). These devices include Atridox ®, PerioChip ®, and Arestin ® (Paper AP 2004).

Tooth Loss, Nutrition, and Diet

Approximately 60 percent of U.S. adults are missing at least one tooth, and 10 percent have no teeth at all (Marcus S et al 1996). Besides the aesthetic value of a nice smile, there are harmful health repercussions to lacking functional teeth, including a greater risk of malnutrition (ADA 2003). People who are missing their teeth have about 20 percent of the chewing capacity of people with teeth, and they tend to avoid eating fruits, vegetables, and whole grains (Moynihan P et al 2001). This can quickly lead to malnutrition and serious vitamin and mineral deficiencies.

Gum Disease, Inflammation, and Chronic Disease

Gum disease is clearly associated with heart disease and other health-related problems. This is not necessarily because of bacterial spread from the mouth into the bloodstream (as many people think). In fact, “bacteria showers” in the bloodstream are relatively common and occur in response to brushing teeth, bowel movements, and other normal activities. These are rarely dangerous for people with healthy immune systems. Rather, the link between gum disease and other systemic diseases appears to be due to an increased inflammatory response that occurs throughout the body and is triggered by inflammation in the gums. The following diseases have been associated with gum disease.

Infective Endocarditis. Infective endocarditis is a serious, potentially fatal bacterial infection of the heart or its valves or inner lining. It occurs when bacteria in the bloodstream are embedded on abnormal heart valves or damaged heart tissue. Dental procedures and diseases are associated with endocarditis in people with underlying congenital heart disease and in those who have prosthetic heart valves or have had other forms of heart surgery (Drangsholt M 1998; Lacassin F et al 1995; Van der Meer J et al 1992). About 8 percent of cases in the U.S. have been associated with periodontitis or other dental diseases without an associated dental procedure. Chances of infective endocarditis following dental procedures in people with pre-existing heart conditions ranged from 1 per 3000 procedures to 1 per 5000   procedures (Drangsholt M 1998). To prevent this condition, some heart patients are advised to take antibiotics during dental procedures.

Cardiovascular Disease. Studies have shown an association between periodontitis and cardiovascular disease (Beck J et al 1999; Loesche W et al 1988; Mattila K et al 1988), and suggest that periodontitis is a risk factor for cardiovascular disease (Loos BG et al 2000; Arbes S et al 1999; Beck J et al 1998). Periodontitis is linked to heart disease by inflammation. According to the latest research, large amounts of bacteria in the gums trigger a systemic inflammatory response, with elevated levels of pro-inflammatory chemicals such as COX (cyclooxygenase) products, arachidonic acid, and others. These pro-inflammatory chemicals may contribute to atherosclerosis, which is now understood to be an inflammatory disease that affects the inner linings of arterial walls (the endothelium). Numerous studies have thus linked inflammatory gum disease to cardiovascular events such as stroke, atherosclerosis, and thickening of calcifications in the carotid artery (Dorfer C et al 2004; Grau A et al 2004; Wu T et al 2000; Ravon N et al 2003; Beck J et al 2001).

Obesity. Obesity, a significant risk factor for numerous diseases, has been associated with periodontitis, gingivitis, and dental cavities (Wood N et al 2003). Other conditions associated with obesity such as metabolic syndrome or Syndrome X (a clustering of dyslipidemia, insulin resistance, hypertension, and type 2 diabetes) can worsen periodontitis (Grossi S et al 1998).

Diabetes. Periodontitis is twice as prevalent in diabetics as in non-diabetics (Loe H 1993). Experimentally produced periodontitis increased blood glucose levels in uncontrolled diabetic animals. Studies have linked the glycation and inflammation in diabetics to worsening periodontitis. Alternatively, studies have linked the inflammatory response triggered by worsening periodontitis to amplified glycation, a damaging process that links proteins to glucose molecules and has been implicated in hardening of the arteries and other diseases (Grossi S et al 1998).

Osteoporosis. Significant relationships exist between periodontitis and osteoporosis (Jeffcoat M 1996, 1998; von Wowern N et al 1994; Streckfus C et al 1997; Ronderos M et al 2000; Tezal M et al 2000; Krook L 1972), and between tooth loss and osteoporosis (Krall E et al 1994, 1996; Tagushi A et al 1999; Grossi S et al 2000).

Pregnancy-Related Issues. Oral infections can increase the risk of low birth weight in newborns (March of Dimes 2000). Pregnant women with periodontitis were found to be 7.5 times more likely to have a pre-term, low-birth-weight infant than pregnant women without periodontitis (Offenbacher S et al 1996). Pregnancy can increase the frequency, severity, and degree of gingivitis (Hugoson A 1970; Loe H 1965).

Lung Disease. Poor oral hygiene provides an ideal growth environment for anaerobic bacteria, which can cause severe pneumonia, especially in people with impaired swallowing (Shreiner A 1979; Komiyama K et al 1985; Costerton J et al 1995; Mergran D et al 1986; Toews G 1986; Fiddian-Green R et al 1991; Levison M 1994; Moore W et al 2000; Appelbaum P et al 1978; Pratter M et al 1980; Scannapieco F 1999).