Is periodontitis contagious?

Dec. 2, 2018
Even though many people do not consider periodontitis to be contagious, there is evidence to support the fact that people who are more susceptible might actually develop periodontitis when exposed to another person with the disease.

Dear Dianne,

Do you know if periodontal disease is transmissible from one person to another? The reason I ask is because one of my long-time patients who has always been periodontally healthy has started showing signs of early periodontitis. Last week, I did a full periodontal charting and noticed several areas of mild inflammation and a number of 4 mm and 5 mm readings. Her last charting (15 months ago) only had two 4 mm readings and everything else was normal. The only thing that has changed in her life is that she remarried 12 months ago. Guess what? Her new husband came in as a new patient and he was diagnosed with moderate-severe periodontitis.

I’ve never thought of periodontal disease as a communicable disease, but now I wonder. Do you have any information about periodontal diseases being transmitted from one person to another?

— Kathleen, RDH

Dear Kathleen,

You’ve posed a very interesting question, and I would be happy to share some information related to the transmissibility of periodontal pathogens.

An article in the Journal of Periodontology posited that, “Periodontal pathogens are communicable; however, they are not readily transmissible.”1 My interpretation is that periodontal pathogens can be transmitted between people, but people are not equally susceptible. There has to be a susceptible host in order for disease to emerge from exposure to certain pathogens. For example, we’ve known for many years that every person who is exposed to HIV does not automatically seroconvert, even though the individual might practice high-risk behaviors. Furthermore, while all communicable diseases are infectious, not all infections are communicable. Tetanus, for example, can cause an infection, but a person with tetanus can’t spread it to other people.

It has been established that parent-to-child transmission of bacteria occurs frequently and is very common. Transmission of bacteria probably occurs in the course of providing care for a child: “As salivary A. actinomycetemcomitans or P. gingivalis are commonly found in adults with periodontitis, it is probable that children are frequently exposed to these bacteria. In one study, A. actinomycetemcomitans was detected 26 times more often in children younger than three years of age if the mother tested positive for the bacterium than if the mother tested negative for the bacterium.”2

To assess whether spouses can transmit periodontitis, von Troil-Linden and others published a study of 20 married couples. What they found was, “the spouses of patients with periodontitis had worse periodontal disease than the spouses of patients without periodontitis, even when possible confounding factors, such as age, sex, and socioeconomic status, had been taken into consideration. It is important to note that the researchers did not choose the spouses of the source subjects based on their periodontal status. The mean age of the spouses in both groups was comparable. The two groups of spouses showed no difference in the proportion of tooth surfaces with visible plaque and gingival bleeding on probing, which suggests that the spouses in both groups practiced similar oral hygiene habits. However, gingival suppuration and supragingival and subgingival calculus tended to occur more frequently in spouses married to patients with periodontitis than in those married to patients without periodontitis. Also, the spouses of patients with periodontitis had significantly deeper periodontal pockets than the spouses of patients without periodontitis.”3

According to Greenstein and other researchers, saliva appears to be a major vector for bacterial transmission. However, the transfer of organisms does not necessarily result in colonization or infection of the host. It is interesting to note that individuals who harbor putative pathogens frequently do not manifest any signs of periodontal disease. The reason disease does not occur can be attributed to host defenses, bacterial antagonism, and possible lack of pathogenicity of infecting organisms.1

I distinctly remember a married couple who became patients in the practice where I worked. Both had severe periodontitis, but the wife’s condition was much worse than her husband’s. She had already lost several teeth, and we charted severe bone loss, suppuration, and mobility. Her condition was so severe that she was treatment planned for full-mouth extractions and dentures.

We referred her husband to a local periodontist for treatment. The husband followed through with the periodontist, and when he came back to our practice several months later, his periodontal health was much improved. He was placed on an alternating three-month schedule between our two offices for maintenance. On the second maintenance visit with me, I noticed some signs of disease activity, namely, bleeding. I felt the patient’s home care was excellent, and he seemed motivated to do whatever was necessary to keep his teeth. He had made great progress and appeared to have gained control of his disease progression.

As I considered what could be causing his condition to reappear, I thought about his wife. She had not followed through with our treatment recommendations. I asked the doctor with whom I worked if it was possible that she was reinfecting her husband. He suggested I call the periodontist and pose that question. When I asked the periodontist, he said that it was indeed possible and highly likely that the husband was being reinfected by his wife.

Later that day I spoke with the wife and discreetly shared with her that her delay in treating her own periodontal infection was in all probability affecting her husband’s ability to maintain the healthy periodontal status we had all worked so hard to achieve. It appeared that the husband was being reinfected by her, and I encouraged her to get started with the treatment she needed, not only for her sake but for her husband’s sake as well. It was not an easy conversation, but it was entirely necessary. The wife came in and completed her treatment plan, including full dentures. The good news for her husband is that his periodontal condition stabilized, and he was able to maintain good periodontal health after his wife received the treatment she needed.

As dental hygienists, we understand that a healthy periodontium is often dependent upon several factors, including good oral hygiene, a healthy diet, stress level, genetics, and the periodontal health of others with whom our patients exchange saliva. Engaging in those discussions effectively requires utmost discretion and excellent communication skills.

All the best,



1. Greenstein G, Lamster I. Bacterial transmission in periodontal diseases: A critical review. J Clin Periodontol. 1997;68(5):421-431.

2. Asikainen S, Chen C, Alaluusua S, Slots J. Can one acquire periodontal bacteria and periodontitis from a family member? JADA. 1997; 128(9):1263-1271.

3. von Troil-Linden B, Torkko H, Alaluusua S, Jousimies-Somer H. Periodontal findings in spouses—a clinical, radiographic and microbiological study. J Clin Periodontol. 1995;22(2):93-99.

DIANNE GLASSCOE WATTERSON, MBA, RDH, is an award-winning author, speaker, and consultant. She has published hundreds of articles, numerous textbook chapters, and three books. Dianne’s new DVD on instrument sharpening is now available on her website at wattersonspeaks.comunder the “Products” tab. Visit her website for information about upcoming speaking engagements. Dianne may be contacted at (336) 472-3515 or by e-mail at [email protected].