FLORIDA COMMUNITY COLLEGE at Jacksonville Dental Hygiene Program

Over the years, various studies have shown that certain organisms related to periodontal disease can be transmitted from one person to another. Most of these studies, however, have focused on the transmissibility between spouses, or between parents and their children. Very little has been said about the possibility of transmission among teenagers. Since saliva is considered to be the primary vector for bacterial transmission, we felt it was important to determine if teens who participate in deep kissing, and other habits which allow the transfer of saliva, are as much at risk of transmitting periodontal bacteria as spouses. In order to determine the possibility of transmission among teens, we conducted a survey of 85 teens between the ages of 16 and 19. The purpose of the survey was to establish the percentage of teens who exhibit signs of periodontal disease, and how many of those participate in activities that could facilitate the transmission of periodontal bacteria.

Scientists discovered in the late 1970's that specific bacteria cause periodontal diseases. In recent years, studies have been conducted to determine if these bacteria could be transmitted among individuals. Through DNA analysis, the transmission of two main culprits of periodontal disease has been shown among parents and their children, and also between spouses.

Two of the most significant bacteria responsible for periodontal disease are Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis. Actinobacillus actinomycetemcomitans is primarily transmitted from parents to their children. This is known as the vertical route. In a study published in 1996 by Oral Microbiology Immunology Journal, it was found that parent to child transmission of Actinobacillus actinomycetemcomitans took place in 32% of families.¹ Although the presence of Actinobacillus actinomycetemcomitans in an individual doesn't necessarily indicate disease, an elevated level would be regarded as a sign of ecological imbalance, leading to increased risk of periodontal destruction.² Although Actinobacillus actinomycetemcomitans is frequently transmitted vertically, it is rarely transmitted among adults.

Porphyromonas gingivalis is an organism that is almost never found in children or individuals in a state of periodontal health. Research has shown that Porphyromonas gingivalis colonizes in the mouth mainly after puberty⁴ and becomes more stable in the late teenage years.³ This indicates that it is possible for a teenager to harbor Porphyromonas gingivalis. Most of the studies involving Porphyromonas gingivalis have focused on the transmission via the horizontal route, which is the transmission among spouses. One particular study reported a 20% rate of transmission among married couples when one spouse was positive for the bacteria.¹

The periodontal bacteria grow most readily in inflamed periodontal pockets, although, they are also found on the tongue, tonsils, mucosal surfaces, and in saliva.⁴ Therefore, any exchange of oral fluids would provide the opportunity for the transmission of bacteria. One factor to consider when determining the possibility of transmitting periodontal bacteria is the frequency of exposure to infectious saliva. The longer an individual is exposed to the microorganisms, the greater the chance of transmission. One study determined that the amounts of Porphyromonas gingivalis in the saliva were elevated the longer spouses cohabitated.⁵ Since a source of microorganisms must be present for an infectious disease to occur, acquisition early in life, combined with long-term exposure, may elevate an individuals chance of developing periodontal disease.

Transmission of periodontal pathogens does not necessarily mean a person will develop periodontal disease. Periodontal diseases caused by Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis are considered opportunistic, therefore, periodontal destruction will depend on the susceptibility of the individual patient. Individuals experiencing a high level of stress, or those suffering with a systemic illness may be more prone to colonization of the destructive bacteria.⁵

Since we know through research studies that P. gingivalis can exist in the oral cavity after puberty, it is important to consider the possibility of transmission among teens. In order to do this we conducted a survey of 85 teenager's aged 16-19. This survey included seven questions pertaining to dental health and eight social questions. One of the purposes of the survey was to determine the percentage of students who had symptoms of periodontal disease. Since there could be underlying problems that could cause the symptoms of periodontal disease, it must be said that the survey was not intended to identify who had periodontal disease, as that would require a clinical diagnosis. It was intended only to identify those who had symptoms of the disease. Since lack of proper oral hygiene is a main contributor to the development of periodontal disease, several questions were included to determine the teenager's frequency of brushing and flossing.

The social questions included in the survey were structured in a way to determine if the teens participated in activities or habits that could transmit periodontal bacteria. Although we were primarily concerned about transmissibility through kissing, we also included questions that would identify transmission possibilities in other ways, such as sharing utensils and cups. Since saliva is the major vector for bacterial transmission, these other routes could not be ignored.

In order to establish those teens at a higher risk of transmission due to continued, frequent exposure, one question was included to determine the longevity of the teen's relationships. Although it would be impossible to compare a one year relationship among teens to that of a twenty year marriage among spouses, it is easy to see that any prolonged exposure to infected saliva would increase the chances of transmission.

Dental Health Questions	Yes	No
1. Do you have your teeth cleaned at least 2 times a year?	48%	52%
2. Do you brush at least 2 times a day?	80%	20%
3. Do you floss every day?	34%	66%
4. Do your gums bleed when you brush your teeth?	15%	85%
5. Are your gums red or swollen?	11%	89%
6. Do you have pus between your teeth and gums?	6%	94%
7. Does either of your parents have missing teeth or wear dentures?	43%	57%

Social Questions
8. Do you ever drink from the same cup as someone else?	48%	52%
9. Do you ever share eating utensils?	39%	61%
10. Do you kiss your parents or siblings on the lips?	21%	79%
11. Do you believe in social kissing?	42%	58%
12. Have you ever shared a deep kiss?	84%	16%
13. If you answered yes to 12, are you presently in a relationship that includes deep kissing?	59%	41%
14. If you answered yes to 13, is this relationship a monogamous one?	86%	14%
15. Have you had a relationship that has lasted more than a year?	51%	49%

When questioned about their oral hygiene care, 80% of the teens surveyed said they brush at least two times per day, however, only 34% floss on a daily basis, and less than half receive professional cleanings twice per year. Although these are less than ideal figures, only a very small number of students actually reported symptoms of periodontal disease. When asked about gingival conditions, only 11% reported red or swollen gums, while 15% said their gums bleed when they brush. Another 6% said they have pus between their teeth and gums. Although these numbers are low, they can not be considered as an accurate portrayal of teens with symptoms of disease. It is possible that some teens do not make it a habit to observe their gingiva on a regular basis. Others may be so accustomed to red and swollen gingiva, that it seems normal to them. A clinical exam is the only way to get a true estimation of those with disease symptoms.

The social questions on the survey show that a high percentage of teens participate in habits that can aid the transmission of saliva. As expected, 84% of those surveyed participate in deep kissing, while 59% are currently in a relationship that involves deep kissing. More than half of those relationships have lasted for more than one year. The majority of the teens said their relationship was a monogamous one, however, 14% said that it was not. For those individuals who are not in a monogamous relationship, their chance of transmitting periodontal bacteria increases.

Although research of transmission of periodontal bacteria usually focuses on spouses and their children, we have shown through our survey that transmission among teens is a real possibility. Due to the less than ideal oral hygiene habits of most teens, the possibility of developing periodontal problems exists. Lack of adequate daily plaque removal, combined with the social habits that expose teens to periodontal pathogens, can place teens in a similar risk group as spouses.

The transmission of periodontal pathogens does not mean that disease will automatically develop. If an individual has a high level of oral hygiene, and their immune system is not compromised, the body can typically fight off the bacteria. Therefore, daily brushing and flossing, combined with regular professional cleanings, are essential for maintaining a healthy oral environment.

1. Asikainen S, Chen C, Slots J. Likelihood of transmitting Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis in families with periodontitis. Oral Micro Immuno. Dec 96: (387-394).

2. Asikainen S, Chen C. Oral ecology and person-to-person transmission of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis. Periodontol 2000. June 99: 65-81.

3. Griffen A, Lamell C, Leyes E, McClellan D. Acquisition and colonization stability of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis in children. J Clin Micro. Mar 2000: 1196-1199.

4. Alaluusua S, Asikainen S, Chen C, Slots J. Can one acquire periodontal bacteria and periodontitis from a family member? JADA. Sept. 97: 1263-1270.

5. Greenstein G, Lamster I. Bacterial transmission in periodontal diseases: A critical review. J Periodontol. May 97: