Friday, June 20, 2014

Take a Look At This YouTube Review of a Listerine Ad!

A Cure-All for Perio Problems?

Listerine created a campaign in the U.K. advertising their Advanced Defense Gum Treatment, noting that 8 out of 10 people have gum disease. The commercial defines gingivitis very simply by stating how poor methods of plaque removal lead to gum inflammation, bleeding gums, and hardened plaque causes gingivitis to worsen to peridontitis and tooth loss. The ad affirms that this product is recommended by dentists, and if used daily after brushing, can protect against germs and plaque, can "repair and restore" gums back to a healthy state in as little as two weeks, and can guard against further gum damage. The video is popular simply for its pitch out to consumers indicating that a liquid product can simply rid gum disease if used regularly, voiding all other forms of non-surgical and surgical treatment. The ad, in my opinion, was created for middle-class adults who are able to purchase products such as Listerine, and who desire a quick and easy fix to a problem that could only be fixed with a visit to the dentist, which can become costly. I believe the argument being made by the ad lacks a lot of evidence, and it would have been more convincing if actual experimental study results were included, as well as real photos of cases in which this miraculous product did "repair gums in two weeks," instead of a virtual tooth and gum model on the screen. Al Habashneh et al. published their findings of the effect of Listerine on gingivitis and dental plaque earlier in 2014, and the researchers concluded based on prior findings and their own clinical samplings of blood and mouth washing habits of a sample population that Listerine could show results of improved gingival (gum) health within four weeks, and that even though Listerine has contained antigingivitis properties was only visible after 6 to 9 month periods. The ad is definitely misleading in telling people to expect such short-term results so fast, and could harm consumer oral health by not specifying that Listerine needs to be used consistently in order to show results. Some consumers lacking proper oral health knowledge may buy the product, use it for two weeks, and then believe that their gingivitis or periodontitis can be cured instantly without further measured. This is an example of an ad that needs reconstruction in order to better reflect the scientific experimentation and reasoning behind why periodontitis should be treated both in and outside of a dental office, with frequent health care check-ups. 
Image from http://i1.ytimg.com/vi/iehxUOHCdjw/hqdefault.jpg

Bibliography

Al Habashneh, R., et al. "The Effect of Listerine Mouthwash on Dental Plaque, Gingival Inflammation and C-reactive protein (CRP)." Dentistry 4.191 (2014): 2161-1122.

Listerine. "LISTERINE® Advanced Defence Gum Treatment - Clinically proven to treat gum disease." Online video clip. YouTube. YouTube, 13 Mar. 2014. Web. 20 June 2014. <https://www.youtube.com/watch?v=iehxUOHCdjw>

Listerine Gum Treatment Used Daily After Brushing. Digital image. Listerine. Listerine U.K., 2014. Web. 20 June 2014. <http://i1.ytimg.com/vi/iehxUOHCdjw/hqdefault.jpg>.


Current Findings on Periodontitis: How the Immune System is Related


Detection of IL-4, IL-6, and IL-12 Serum Levels in Generalized Aggressive Periodontitis

Summary

In September of 2011, experimenters Robati, Ranjbari, Boroujerdnia, and Chinipardaz measured how periodontitis is related to the immune system's function, and compared the roles of cytokine networks, which regulate inflammation, immunity function, and the specific cytokines under study (IL-4, IL-6, and IL-12) are growth and activation factors for B cells, T cells, and natural killer cells. The experimenters observed the cytokines' specific involvement in cases of periodontal disease. The researchers noted that chronic periodontitis is caused by the oral cavity's defense system trying to fight off dental plaque antigens that want to infect the mouth and specifically the gums. The researchers also discussed how T cells are extensively involved in periodontitis, since they regulate immunity and can be measured in cases of periodontal disease. Robati et al. (2011) sought to measure patients with aggressive periodontitis versus a control group in order to measure the presence or absence of the specified cytokines IL-4, IL-6, and IL-12, since previous studies had proven that IL-4 has been known to suddenly cause periodontal disease.

The researchers selected twenty-five Iranian patients from ages 20 to 36 that were referred to the Periodontal Clinic of Ahvaz Jundishapur University of Medical Sciences. The control group included 25 healthy patients who were undergoing crown lengthening procedures by a licensed dentist prior to the study. The medical and dental histories of both cases and controls were collected, including information on HIV infections, pregnancy, medications that affect cytokine function, and smoking habits. The attachment of gum tissue to teeth was measured in at least 3 affected teeth, and all patients had 5 or 6 teeth with greater than 5 mm of periodontal disease-related gum tissue recession. Surgical techniques were used, including restorative crown lengthening, pocket reduction of gum tissue where gum flaps were contoured properly, fracture lines in teeth were corrected, and crown lengthening helped alleviate gum and bone loss associated with cavities. Blood samples of the patients were collected during periodontal pocket reduction surgery, and control groups' blood samples were taken before extractions in noninflammatory areas, in order to assess white blood cell count. The cytokine assay used to test for IL-4, IL-6, and IL-12 presence included an enzyme-linked immunosorbent assay which tests for antibody presence to locate a particular antigen, and absorbance readings at 450 nm from a spectrophotometer measured cytokine presence. T-tests were used to quantify the data collected.

The researchers found that cytokines were present in all of the sample population in differing amounts; however, IL-4 levels were higher in the control group than the case group, while IL-6 was found more abundantly in the case group. There was a non-significant decrease in IL-12 in the case group versus the control group. Cytokines are definitely involved in the process of regulating tissue regrowth, immune response, and inflammation related to periodontitis. The findings reaffirmed previous findings of how cytokine IL-4 was found in decreased amounts in periodontitis patients versus people without periodontitis. In addition, IL-6 levels were increased in the periodontitis patients versus the control group, and the findings are supported by previous findings that indicate how IL-6 is necessary in bone recovery. Although no significant different in the levels of IL-12 between periodontitis patients and the control group population, IL-12 levels were lower in patients affected by periodontitis, which was supported by previous findings connecting IL-12 levels to periodontal inflammation. There is a protective affect offered by IL-4 levels that are high.

Here are the findings tabulated from the experimenters:
Image from http://www.iji.ir/september2011/4thiji_vol8_no3_2011.pdf

Image from http://www.iji.ir/september2011/4thiji_vol8_no3_2011.pdf


















Recommendations for Future Research

In order to further investigate if IL-12 levels truly play a significant role in inflammation related to periodontitis, researchers should do another ELISA analysis with patients who have elevated levels of IL-12, and measure only patients who have aggressive periodontitis to see how their personal factors affect the production of IL-12 related to periodontitis. In addition, samples from different hospitals should be included to show a more generalized picture of the population that has periodontitis. In addition, the activity of bacteria associated with periodontitis should be measured more thoroughly through microscopic methods in patients who had decreased IL-4 levels and generalized aggressive periodontitis. Another study could also assess how cytokines are related to different stages of periodontitis and not just the severe stage, in order to generalize the activity of cytokines across the spectrum of less severe to severe periodontitis infections.

Bibliography for this Section:

Robati, M, A Ranjbari, Boroujerdnia M. Ghafourian, and Z Chinipardaz. "Detection of Il-4, Il-6 and Il-12 Serum Levels in Generalized Aggressive Periodontitis." Iranian Journal of Immunology : Iji. 8.3 (2011): 170-5. Print.

Disease Transmission and Treatment/Prevention


Disease Transmission

B. subtilis visualized with a Gram stain from http://faculty.mc3.edu/jearl/ML/b_subtilis.jpg

From the research of Yamane et al. (2009), bacteria develop communities called biofilms, and this has been linked to the cause of periodontal disease. Specifically, through rRNA sequencing, strains of B. subtilis were responsible for forming biofilms in periodontal lesions, or empty spaces caused by gingivitis and periodontitis development (Yamane et al., 2009). The bacteria isolated from the root canals of teeth with periodontitis were Gram-positive (containing a thick peptidoglycan layer encapsulating the organism) and produced excess amounts of exopolysaccharide (protective secretions that allow the bacteria to spread) to form biofilms that were able to successfully multiply in the host environment of the oral cavity (mouth) (Yamane et al. 2009). According to Mayo Clinic's (2014) extensive description of periodontitis, the beginning of periodontitis is when plaque forms due to the interaction of starchy and sugary food with oral bacteria. Failure to remove plaque with brushing and flossing causes it to harden in about three days forming tartar, which harbors bacteria more easily within the mouth, causing primarily inflammation associated with gingivitis, then pockets form in the gum tissue connecting to the teeth, which gives bacteria the ability to deposit metabolic endotoxins that cause inflammation and deterioration (Mayo Clinic Staff, 2014). The resulting infection causes bone loss and tissue loss (Mayo Clinic Staff, 2014). In addition to the severe bone and tissue loss associated with periodontitis, tooth loss, coronary artery disease, stroke, premature births, diabetes, arthritis, and asthma have been linked to periodontitis, since bacteria that accumulates within the gums can easily slip into the blood stream to affect other parts of the body, and even lead to narrowing of the arteries (Mayo Clinic Staff, 2014). According to the American Academy of Periodontics, periodontitis can be spread through contact with saliva from mouth to mouth, shared oral health tools, and eating/cooking utensils if put in the mouth (2014). The main mode of transmission of periodontitis is saliva. You will not get periodontitis if the saliva of an infected person gets on your skin. That saliva must somehow find its way into your own mouth for you to become infected. Therefore, periodontal disease is contagious in its spread through saliva and mouth contact.
Image of a severe stage of periodontitis with gum recession from the teeth, from colgateprofessional.com

Risk Factors 

Some of the risk factors for periodontitis mirror those for other common diseases. To be put simply, if whatever you are doing is bad for your mouth, chances are it will contribute to gingivitis which can lead to periodontitis if you already have improperly treated gingivitis! For example, smoking can heighten the risk of developing periodontitis since the chemicals in cigarettes wear away your gums. In girls and women, hormonal changes resulting from puberty or the menstrual cycle can cause gums to become ultra sensitive making gingivitis easier to develop. Having diabetes, cancer, autoimmune disorders, or any type of illness that can increase the risk of developing infections can also be a risk factor for periodontitis. In addition, medications that reduce the flow of saliva in the mouth or increase abnormal overgrowth of the gum tissue also pose a risk for developing periodontitis. Crowding of teeth can also contribute to periodontitis. Overgrowth of the gums or crowding of the teeth causes some parts of the tooth to be improperly cleaned, and efficient coats of saliva are needed for teeth to have some form of protection against oral infections. Poor restorations done in a clinical setting to the teeth can also contribute to periodontal disease. There are also some genetic factors that can make people susceptible to periodontitis. (Source for this passage: NIH, 2012)

In addition, a study conducted by Van Dyke and Dave (2005) showed that there has been a correlation between old age and periodontitis, due to the body's weakened process of tissue regeneration especially in the gums, as well as an increased incidence of periodontitis in those with bone loss or weakened bones caused by osteoporosis, and increased incidence in individuals who suffer frequent stress, causing them to have weakened immune systems and a lesser tendency to pay attention to regular oral hygiene.
Smoker's teeth with periodontitis from studiodentaire.com


Prevalence of Disease

According to a study conducted with the Center for Disease Control and Prevention from my previous post, periodontitis is prevalent in about 47.2% of adults aged 30 years and older, while the disease increases with age in the United States alone (Eke et al., 2012). The World Health Organization estimates that 60-90% of school children and 100% of adults have dental cavities and excess plaque that leads to periodontitis (WHO, 2012). Severe periodontal disease, specifically, is found in 15-20% of middle-aged adults across the world, and periodontitis is one of the most common oral diseases known to exist (WHO, 2012). However, the prevalence of periodontitis and periodontal disease decreases in geographic regions with with readily accessible and affordable dental care, and increases with low and middle-income countries, especially developing countries with a high poverty rate (WHO, 2012). For example, in the United States, areas that have higher prevalence of other diseases due to unaffordable health care are more likely to have periodontitis among the most frequently occurring diseases. Periodontitis is a product of lack of access to decent oral healthcare, lack of education, and lack of oral health awareness. 

Treatment and Prevention

According to the World Health Organization (2012), oral health is linked to overall health, so preventing periodontitis also decreases a person's risk for other related diseases. World Health Organization lists some basic prevention practices so that you can avoid periodontitis:
  • Increasing nutritional awareness,  increasing healthy food choices, and decreasing sugar intake
  • Consuming fruits and vegetables that contain antioxidant properties and prevent against oral cancer
  • Daily, proper oral hygiene (adequately brushing and flossing twice a day with a usable tooth brush and clean strand of floss)
  • Using protective mouth gear during sports and other activities that could injure the mouth 
  • Long-term exposure to fluoride through fluoridated drinking water, tooth paste, salt, and milk
  • Access to affordable oral health care (however, this may be impossible for some age groups and people located in certain geographic regions)
Daily toothbrushing is important for prevention of periodontitis! From chambersburgdentalnews.com
Treatment of periodontitis is extensive and available. Both nonsurgical and surgical options are available depending on the severity of disease progression. Non-surgical treatment according to the American Academy of Periodontology (AAP) includes scaling and root planing, in which a certified hygienist cleans the root surfaces to remove deep bacteria and then follows with an antimicrobial agent injected into the gum pockets, such as Arestin (2014). In addition, patients can be fitted with oral trays that can deliver medication applied to the tray at the surface of the gums (American Academy of Periodontology, 2014). Surgican procedures prescribed by the AAP include gum graft surgery, in which gum tissue from the palate can be used to cover roots and promote gum growth and reduce sensitivity of the exposed tooth (2014). According to the AAP, gum grafts have extensive benefits which include reduced bone loss and reduced gum recession, as well as protection from decay (2014). Regenerative procedures to reduce gingival pocket depth prescribed by the AAP (2014) include regenerative procedures, in which gums are folded back to expose and remove bacteria, followed by a bone graft and tissue stimulating proteins, and dental implants can be placed to combat tooth loss caused by periodontitis, as well as plastic surgery methods such as jaw ridge augmentation. Many of the costly surgical procedures require time, patience, and dedication of the patient and doctor.

The Blogger's Thoughts on Prevention/Treatment

I believe that the treatment available is definitely advanced and has many options. However, in terms of geographical area affected by periodontitis, lack of poor education, a rural environment, and lack of access to health care may inhibit people in these regions from fully being able to combat periodontitis (WHO, 2014). In addition, surgical treatment is often costly, and requires time and dedication from the patients and doctors. If one of these parties does not cooperate, the proper treatment cannot be given optimally. From a global standpoint, I believe access to surgical and basic oral healthcare practices in order to treat and prevent periodontitis may be a problem. However, if these treatmes are readily accessible, they would definitely offer a great amount of relief for those who suffer periodontitis. Non-surgical procedures such as regular checkups and hygiene visits can greatly reduce the incidence of periodontitis if the populace has access to the care and does not fall out of care or fail to seek dental care. While surgical treatments are definitely corrective, I believe these treatments can easily be reversed if the patient does not follow-up with improved oral hygiene habits or frequent check-ups. In addition, periodontal antibiotics, such as azithromycin, may be inaffective if the person develops resistance from constant exposure to antibiotics or if the cigarette smoking individual continues smoking, which has been proven in randomized clinical trials to reduce the efficacy of periodontal antibiotics used to treat periodontitis specifically in smokers (Pradeep et al., 2013).

Bibliography of Section

Brush Teeth Close. Digital image. Chambersburg, PA Dentist Talks about Brushing Teeth. Donnell McHenry, Jr., D.D.S., 21 Nov. 2013. Web. 14 June 2014. <http://www.chambersburgdentalnews.com/wp-content/uploads/2013/11/Brush-Teeth-Close.jpg>.

Eke PI, Dye B, Wei L, Thornton-Evans G, Genco R. Prevalence of Periodontitis in Adults in the United States: 2009 and 2010. J Dent Res. Published online 30 August 2012:1–7.

Pradeep, AR, P Bajaj, E Agarwal, NS Rao, SB Naik, N Kalra, and N Priyanaka. "Local Drug Delivery of 0.5% Azithromycin in the Treatment of Chronic Periodontitis Among Smokers." Australian Dental Journal. 58.1 (2013): 34-40. Print.

Yamane, K, K Ogawa, M Yoshida, H Hayashi, T Nakamura, T Yamanaka, T Tamaki, H Hojoh, K.P Leung, and H Fukushima. "Identification and Characterization of Clinically Isolated Biofilm-Forming Gram-Positive Rods from Teeth Associated with Persistent Apical Periodontitis." Journal of Endodontics. 35.3 (2009): 347-352. Print.


"Periodontal (Gum) Disease: Causes, Symptoms, and Treatments." National Institute of Dental and Craniofacial Research: Part of the NIH, 1 Aug. 2012. Web. 20 June 2014. <http://www.nidcr.nih.gov/nidcr2.nih.gov/Templates/CommonPage.aspx?NRMODE=Published&NRNODEGUID=%7bCE246689-D899-4CC7-B68A-805AD910F4E7%7d&NRORIGINALURL=%2fOralHealth%2fTopics%2fGumDiseases%2fPeriodontalGumDisease%2ehtm&NRCACHEHINT=Guest#howDoI>.

Periodontal Disease. Digital image. Studio Dentaire. Studio Dentaire, 2012. Web. 13 June 2014. <http://www.studiodentaire.com/articles/en/smoking-and-gum-disease.php>.

Smoker's Periodontitis. Digital image. Zestfulness: Periodontitis: Do You Know If You Have It? Colgate Professional, 22 May 2011. Web. 20 June 2014. <http://www.colgateprofessional.com/LeadershipUS/PatientEducation/Images/Resources/pated_PeriodontitisAdvance.jpg>.

"Treatments | Perio.org." Treatments | Perio.org. American Academy of Periodontology , 1 Feb. 2014. Web. 20 June 2014. <http://www.perio.org/consumer/treatments_procedures>.


Van Dyke, D.D.S., PhD., Thomas E., and Sheilesh Dave. "Risk Factors for Periodontitis." . Journal of the International Academy of Periodontology, 7 Jan. 2005. Web. 14 June 2014. <http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1351013/>.

The History, Statistics, and What You Need to Know About Periodontitis


What is Periodontitis?


According to the National Institute of Dental and Craniofacial Research, when gingivitis, also known as inflammation of gums in the mouth, does not become controlled by proper oral hygiene or treatment, periodontal disease can occur. Periodontal disease is an infection that affects the gums in your mouth, in which the gums recede away from the teeth to form holes that can become infected by bacteria; severe damage of the soft tissue and bones attached to your teeth can occur. When plaque accumulates on the teeth without some way of consistent removal, the plaque will spread below the gum line, harmful bacteria can be released, and this is what causes the breakdown of soft tissue and bone underneath the teeth. Sometimes teeth have to be removed due to the severity of periodontitis present.

Entire Source of This Section: (NIH Publications, 2012)

Image of normal gums versus inflamed gums with periodontal disease from http://tribecanydentistoffice.com/wp/wp-content/uploads/2014/05/periodontitis.jpg



The Root of the Problem: Statistics and History

Dr. John Mankey Riggs. Photo courtesy of 3.bp.blogspot.com
Periodontitis was first observed in the 18th and 19th century through empirical guesses and observation by Dr. John Mankey Riggs, a dentist who focused on periodontal cases, named the disease as Riggs disease or pyorrhea, and researched and published his findings on therapeutic methods for periodontal ailments; further developments in periodontal disease knowledge followed with the development of advanced microscopy methods for observing bacteria in gum tissue (New Mexico Dental Hygienists Association, 2014). In addition, Riggs found that periodontal disease caused inflammation of the gums and the teeth would be surrounded in infectious pus which weakens them (Katz, 2012).

According to the American Academy of Periodontology, over half of American adults have periodontal disease (Eke et al., 2012). Collected data from the CDC's 2009-2010 National Health and Nutrition Examination Survey contained a "full -mouth periodontal examination," and researchers found the following statistics in the United States:
  • Periodontal disease occurs more highly in men (56.4% versus 38.4% in women)
  • Mexican Americans had the highest rate of occurrence of periodontal disease for a particular race (66.7%)
  • High prevalence rates were found in smokers (64.2%), the poor (65.4%), and people with less than a high school diploma (66.9%)
  • 47.2% or 67.4 million adults in the U.S. have some form of periodontitis 
American Academy of Periodontology noted that Dr. Paul Eke (2012) put fault on public health programs that fail to promote oral health awareness, and he observes that periodontal disease definitely affects the population that is over the age of 65 years old at a higher rate than other age groups.

Clinical Symptoms

According to Mayo Clinic, some physical symptoms of periodontitis include gum swelling, red or purple gums, tender feel in the gums, recession of gums that exposes more of the tooth to your mouth and the environment, bleeding or sensitive gums, spaces or pockets developing in between teeth, pus between teeth or gums, foul odor of the mouth, a bad taste in the mouth, weak or loose teeth, and having a bite that shifts or feels as though the teeth move around (Mayo Clinic Staff, 2014).

Detection and Diagnosis

Periodontitis develops gradually according to the Mayo Clinic (2014). Healthy gums are usually pinkPeriodontitis can come in two forms (Mayo Clinic Staff, 2014). Chronic periodontitis is a common form of the disease that affects mostly adults, and the symptoms are gradually present asymptomatically at first. Aggressive or acute periodontitis shows severe symptoms right away, and only a small number of people, usually children and teens, are infected (Mayo Clinic Staff, 2014).

According to the NIH's information page of periodontitis, a dental x-ray showing bone loss may be used in diagnosing periodontitis properly. In addition, a periodontist who specializes in gum treatment may be able to further categorize the stage of periodontal disease present through further examination of dental and medical histories (2012). 

According to the Journal of Clinical Periodontology (2000), diagnosis of the different levels of periodontitis is classified with respect to gum recession present. Minor periodontitis entails bone loss that is less than 1/3 of the root length, less then 3 mm, while moderate periodontitis includes 2 or more infected teeth, bone loss at greater than 1/3 of the root, and 4 to 5 mm of lost attachment of gum tissue, and severe periodontitis is categorized by more than 2 infected teeth, bone loss at 1/2 the root length or more, and about 6 mm or more of gum tissue loss (Journal of Periodontology, 2000).

A periodontist examining a dental x-ray to detect bone loss in a patient,  from http://riversidedentalblog.com

Post Bibliography

"CDC: Half of American Adults Have Periodontal Disease | Perio.org."CDC: Half of American Adults Have Periodontal Disease | Perio.org. American Academy of Periodontology , 1 Jan. 2012. Web. 20 June 2014. <http://www.perio.org/consumer/cdc-study.htm>.

"Diagnosis of Periodontitis." Journal of Clinical Periodontology. 27.12 (2000): 960-961. Print.

Dr. John M. Riggs. Digital image. The Painful History of Painless Dentistry. Dr. Wendell A. Howe, 31 Jan. 2012. Web. 14 June 2014. <https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhqWL_Y_Dh3ULa7JM82vyjBYEsqtYfNC0Tg_1eHeKRe-0uO9got-Uhryj2562n68EcwaKq2m0BGlw-_sccMpghh8NkQH-kshIXI2WVRtARRqYMcKCqtokVqyjks7kCLdOBVjo60BZMVlW4/s1600/Riggs_John_M.jpg>.

Katz, D.D.S., Harold. "The long, gross history of periodontal disease." The long, gross history of periodontal disease. N.p., 1 Jan. 2012. Web. 18 June 2014. <http://www.therabreath.com/articles/blog/fresh-breath-happenings/the-long-gross-history-of-periodontal-disease-5638.asp>.

P.I., Eke , Dye B. A., Wei L., Thornton-Evans G. O., and Genco R. J.. "Prevalence of Periodontitis in Adults in the United States: 2009 and 2010." Prevalence of Periodontitis in Adults in the United States: 2009 and 2010. Journal of Dental Research , 18 Sept. 2012. Web. 20 June 2014. <http://jdr.sagepub.com/content/early/2012/08/29/0022034512457373.abst

Periodontal Disease X-Ray Examination. Digital image. Riverside Dental Blog. N.p., Mar. 2012. Web. 14 June 2014. <http://riversidedentalblog.com/wp-content/uploads/2012/03/gum-disease.jpg>.


"Periodontal (Gum) Disease: Causes, Symptoms, and Treatments." National Institute of Dental and Craniofacial Research: Part of the NIH, 1 Aug. 2012. Web. 20 June 2014. <http://www.nidcr.nih.gov/nidcr2.nih.gov/Templates/CommonPage.aspx?NRMODE=Published&NRNODEGUID=%7bCE246689-D899-4CC7-B68A-805AD910F4E7%7d&NRORIGINALURL=%2fOralHealth%2fTopics%2fGumDiseases%2fPeriodontalGumDisease%2ehtm&NRCACHEHINT=Guest#howDoI>.

"Periodontitis." Symptoms. Mayo Clinic Staff, 1 Jan. 2014. Web. 17 June 2014. <http://www.mayoclinic.org/diseases-conditions/periodontitis/basics/symptoms/con-20021679>.

"Periodontium Image ." . Tribecany Dentist Office , 1 Jan. 2013. Web. 20 June 2014. <http://tribecanydentistoffice.com/wp/wp-content/uploads/2014/05/periodontitis.jpg>.

"The Roots of Periodontology." . New Mexico Dental Hygiene Association, 1 Jan. 2014. Web. 19 June 2014. <http://www.nmdha.org/docs/The_Roots_of_Periodontology.pdf>.