Perio Reports provides easy-to-read research summaries on topics of specific interest to clinicians. Perio Reports research summaries will be included each month to keep you on the cutting edge of dental hygiene science.

Water compared favorably to iodine in ultrasonic scaler

Furcations present a great challenge to clinicians and patients for treatment and daily control of bacterial biofilm. Furcations respond less favorably to treatment than teeth without furcations. Difficulty with access to remove bacterial biofilm and calculus is the underlying problem. Some researchers/clinicians suggest the use of chemicals to enhance the mechanical debridement of furcation sites.

Researchers in the School of Dentistry at the University of Campinas in Såo Paulo, Brazil designed a 6-month study to evaluate the effectiveness of 10% povidone iodine used as the coolant in an ultrasonic scaler. This therapy was used to treat Class II mandibular furcations that bled and measured 5 mm or more. A total of 44 patients completed the study, which included oral hygiene instructions and restorative care before baseline, full-mouth debridement with an ultrasonic scaler, maintenance visits twice during the first month after treatment, and monthly for the remaining five months.

Baseline data included plaque levels, probing depths, attachment levels, recession levels, bleeding upon probing and microbial testing of the plaque biofilm. One clinician provided all the treatment and another completed all the examinations.

No significant differences were observed between the test and control groups. Both showed significant healing, with probing depths reduced 2 mm, gain in clinical attachment of 1 mm and a gain in horizontal attachment of 1 mm. Bacterial data showed a significant reduction in activity at one month and a return to baseline levels at three months for the control and a return to slightly less than that for the test group, but the difference was not statistically significant. Furcation sites that required re-treatment at three months because they were still 5 mm or deeper and bleeding were slightly fewer in the test group compared to the control group, but this difference was also not statistically significant.

Clinical Implications: Study findings vary on the use of povidone iodine as the coolant with ultrasonic scaling. It seems ultrasonic scaling with water in furcations is quite effective. Your standard approach should be ultrasonic scaling with water coolant for both plaque and calculus removal in Class II furcations. For sites that do not respond after six months of treatment and frequent maintenance, alternative approaches need to be considered.

Ribeiro, É., Bittencourt, S., Ambrosano, G., Nociti, F., Sallum, E., Sallum, A., Casati, M.: Povidone-Iodine Used as an Adjunct to Non-Surgical Treatment of Furcation Involvements. J Perio 77: 211-217, 2006.

Blood vessel walls altered by periodontal disease

Half of the people diagnosed with cardiovascular disease do not have the classic risk factors of smoking, high cholesterol, lack of exercise or genetics. Athersclerosis is an inflammatory disease with the immune response believed to be involved in the formation and growth of atheromas.

Chronic infections, like periodontal disease, may be involved with artheroma formation. A review of laboratory studies concludes that P. gingivalis can invade endothelial cells, the cells that comprise blood vessel walls. P. gingivalis can trigger the release of specific substances from the endothelial cells that begin artheroma formation.

Four theories are suggested to explain this connection. First, “Microbial Invasion,” is the invasion of endothelial cells by periodontal bacteria that activate endothelial cells to trigger an immune response, resulting in the formation of an artheroma. Second, “Immunological Sounding” is triggering of the immune system by a periodontal infection and the subsequent release of substances into the blood stream and the activation of endothelial cells, leading to artheroma formation. Third, “Pathogen Trafficking,” explains how pathogenic bacteria are transported inside an inflammatory cell to another part of the body where endothelial cells are activated to allow entrance of these cells. Fourth, “Auto-immune Reaction,” occurs when bacteria elicit specific antibodies that react with host cells. One or a combination of some or all of these processes may take place.

Clinical Implications: The link between periodontal disease and heart disease becomes clearer when we understand how oral bacteria may change blood vessel walls. Periodontal infection may be the first step in the development of an arthroma. Research continues in this area.

Gibson, F., Yumoto, H., Takahashi, Y., Chou, H., Genco, C.: Innate Immune Signaling and Porphromonas Gingivalis Accelreated Atherosclerosis. J Dent Research 85: 106-121, 2006.

The perio-system link is a two-way street

Dr. L. Golub, the researcher who developed the “perio pill,” a subantimicrobial dose doxycycline, presents an interesting model to describe how systemic diseases contribute to periodontal disease. It’s more than just adding to existing periodontal disease, it’s a role in the onset of periodontal disease. It’s a “Two-Hit Model” for the onset of disease with the first hit being the bacterial biofilm endotoxins that breakdown connective tissue and bone. The second hit is the increase in the blood stream of inflammatory markers likes C-Reactive Protein (CRP) and matrix metalloproteineases (MMPs) like collagenase, that act like chemical machetes destroying healthy connective tissue. These substances are similar whether the inflammatory process is going on in the joints from arthritis, in the bone from osteoporosis, in the circulatory system or the lungs. Increased inflammation in other parts of the body can bring substances to the gingival tissues that trigger periodontal destruction. It’s a complex, two-way cascade of cellular events that seems to result in the co-induction of periodontal disease, not just a modification of the process.

Animal and human studies support this model. When arthritis is induced in rats, systemic inflammation destroys bone, cartilage, tendons and ligaments. Alveolar bone loss is also evident, without changing the oral flora. When these rats were given a non-antimicrobial, chemically modified tetracycline, the tissue destruction in joints and jaws was stopped because the cytokines were reduced.

Human studies have shown that both adults and children with arthritis have more periodontal disease than others their age. This suggests that inflammatory substances associated with arthritis induce as well as aggravate periodontal disease.

Clinical Implications: Observe patterns in your patients between systemic disease and periodontal disease. Your data gathering will extend from the mouth and periodontal tissues to systemic conditions such as arthritis, osteoporosis, heart disease and lung disease. The circulatory system is a two-way street, moving inflammatory markers and cytokines back and forth from one part of the body to another.

Golub, L., Payne, J., Reinhardt, R., Nieman, G: Can Systemic Diseases Coinduce (Not Just Exacerbate) Periodontitis? A Hypothetical “Two-Hit” Model. J Dent Research 85: 102-105, 2006.

Bacteria spread from parent to child

Several studies have reported the transmission of bacteria from parents to children. Researchers at the University of Michigan, School of Dentistry used a chairside BANA test to determine if parents and children had the same bacteria. The BANA test detects an enzyme present in Porphyromonas gingivalis (Pg), Treponema denticola (Td), and Tannerella forsythensis (Tf). Interproximal plaque samples are removed with a toothpick and wiped onto the lower strip of the BANA card that was then folded in half and placed in the incubator for 5 minutes at 131ºF (55ºC). Color change on the card ranges from no blue, which is negative to distinct blue which is positive.

Plaque scores, bleeding scores and DMFT (decayed, missing and filled teeth) scores were also recorded for 150 children and 107 mothers, 30 fathers and three grandparents. The children ranged in age from 3 to 10 years. DMFT scores were six for those with primary teeth (63 children), one for those with mixed dentition (84 children) and zero for the three with permanent dentition.

BANA tests were positive for 70% of the parents and positive for 84% of their children. Seven percent of children were BANA positive despite their parents being negative. More older children were BANA positive compared to younger ones. Of the children of BANA positive parents, 63% of the younger group was positive compared to 92% in the older children. This may be due to an environment in the mixed dentition mouth conducive to interproximal bacterial colonization. Bleeding during tooth eruption provides a nutrient source for the bacteria, thus promoting colonization. Plaque scores did not correlate with BANA scores; however, bleeding scores did.

Clinical Implications: Parents who sacrifice their own oral health for their children by forgoing dental/dental hygiene visits for themselves and instead, send their children should be aware of the spread of bacteria from parent to child. Good oral health should be the goal for all members of the family.

Lee, Y., Straffon, L., Welch, K., Loesche, W.: The Transmission of Anaerobic Periodontopathic Organisms J Dent Research 85: 182-186, 2006.

The right xylitol dose needed to reduce bacteria

Xylitol is a natural sweetener that can reduce dental caries. Just how that occurs it still unclear. Several theories have been suggested. Xylitol may inhibit Strep mutans from adhering to the teeth, it may reduce the number of Strep mutans thus reducing the amount of acid produced, or xylitol use may reduce acid production by other sugars. The exact mechanism of action has yet to be determined.

For xylitol to be a cost effective public health measure, we need to know the lowest dose and ingestion frequency needed to achieve clinical benefit. Researchers at the University of Washington compared three total daily xylitol doses of chewing gum given to 120 adults over six months. A fourth group was given gum sweetened with sorbitol and maltitol. Subjects were instructed to chew three pellets for five minutes or more, four times daily. To ensure compliance, the assigned gums were distributed weekly for the first five weeks and then biweekly for the remainder of the six months. The doses tested were: 3.44 grams, 6.88 grams, and 10.32 grams. Plaque and saliva were collected at baseline, five weeks, and six months. Plaque was scraped off all buccal surfaces of all the teeth.

Strep mutan levels in the plaque were reduced tenfold from baseline to five weeks and also at six months for those chewing 6.44 grams and 10.32 grams of xylitol. Based on cultures of the plaque, the xylitol affected the Strep mutans without altering the numbers of other bacteria in the plaque. Salivary levels of bacteria were also lower for these two groups, and unchanged in the group chewing 4.33 grams per day. Expecting people to chew xylitol gum four times per day is not realistic, so researchers are now comparing the effects of 10.32 grams per day spread over two, three and four daily doses.

Clinical Implications: Xylitol chewing gum needs to be chewed four times per day for a total dose of 6 to 10 grams per day. Achieving a xylitol daily dose of less than 6 grams will not provide the anticariogenic effects desired.

Milgrom, P., Ly, K., Roberts, M., Rothen, M., Mueller, G., Yamaguchi, D.: Mutans Streptococci Dose Response to Xylitol Chewing Gum. J Dent Research 85 177-181, 2006.

Fluoride varnish prevents early childhood caries

The prevalence of caries in preschool children is reported to be 14%. Among low-income families enrolled in Head Start programs the rates are much higher, 44% among Asians and 39% for Latinos. Early childhood caries is a public health problem, sometimes requiring general anesthesia in the hospital.

Fluoride varnish is an effective means of remineralizing enamel, reversing white spot lesions and preventing caries. Nearly all studies have been restricted to the permanent teeth of school-aged children. Researchers at the University of California, San Francisco designed a study to evaluate the effects of fluoride varnish on deciduous teeth.

Children with erupted anterior teeth and no caries were enrolled in the study at two public health centers in San Francisco. The average age was 1.8 years (six months to 44 months). These centers primarily serve low income, underserved Hispanic and Chinese populations. The study began with 384 participants, expecting that not all would complete the two-year study. Subjects were randomly assigned to one of three groups: no fluoride varnish, varnish once/year and varnish twice/year. Counseling and oral hygiene instructions were given to all the children’s caregivers. According to guidelines from the American Academy of Pediatric Dentistry, children receiving an exam must also be provided oral health counseling.

Not all studies go as planned, and this is one. Saliva samples were collected from the children to measuring fluoride levels before varnish application, and at several time points following application. During a 10-month period, the data showed an unusual finding – no change in salivary fluoride levels despite fluoride varnish applications. This prompted an outside evaluation of Duraphat fluoride varnish tubes to determine fluoride content. No fluoride was found in the tubes. They were placebo products, although this study did not include a placebo varnish. A valuable lesson was learned, the value of quality control as part of the study design.

Information was still gleaned from the study, despite the fact that children who were to receive two applications only received one and those scheduled to receive four, received two and in a few cases, three. The findings did show a benefit of fluoride varnish over counseling and education alone. The rate of decayed/filled surfaces was 1.6 lesions and the rate of pre-cavitated lesions was 2.7 for the no-fluoride group. For those receiving three to four applications of fluoride varnish the rates were 0.1 and 0.6, respectively. Of the children returning for examinations, caries were diagnosed in 42 children in the counseling only group, 23 in the two-application group and 14 in the four-application group.

Clinical Implications: Start using fluoride varnish as soon as a child’s teeth erupt, especially children at high risk for dental caries.

Weintraub, J., Ramos-Gomez, Shain, B., Hoover, C., Featherstone, J., Gansky, S.: Fluoride Varnish Efficacy in Preventing Early Childhood Caries. J Dent Research 85: 172-176, 2006.