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.

C-reactive protein levels correlate with heart disease

Since some people experience heart disease without the traditional risk factors, researchers are looking for new predictors of disease to allow early intervention and prevention. A protein produced by the liver called C-reactive protein is a marker of underlying inflammation in the body. Elevated levels of C-reactive protein are associated with heart disease, with peak levels being reached within 48 hours of an acute myocardial infarction or heart attack.

It has been suggested that periodontal disease may increase C-reactive protein levels, but research to date is controversial. Most of the studies reviewed on this topic lacked confirmed medical and dental diagnosis. Patients are often simply asked if they have or have had gum disease or heart disease with no medical or dental examination to confirm findings.

Researchers at Kristianstad University in Sweden evaluated 85 consecutive subjects admitted to the hospital for heart problems. Evidence of heart disease was confirmed by a cardiologist. Following discharge from the hospital, patients were examined by a periodontist to determine periodontal status. These patients were then asked to bring a friend their age to the clinic for cardiovascular and periodontal examination. Approximately 30 of these patients qualified as heart healthy controls, and another 30 control patients were recruited for a total of 63.

As expected, a majority of heart disease patients had elevated C-reactive protein levels, with an average score for the group of 18.4 and a range of scores from 0.3 to 109.0. A score over 2.0 was found in 79% of this group. In health, C-reactive protein is undetectable in the blood or found at levels below 0.6 mg/l.

The mean C-reactive protein level score for the control group was 2.5 with scores ranging from 0.2 to 6.4. A score over 2.0 was found in 41% of this group.

Periodontitis was indicated by bone loss and bleeding, although full periodontal records were taken. Bleeding upon probing levels were higher for those with heart disease compared to the control group. Interproximal alveolar bone loss as measured on radiographs was higher in the heart disease group. All the heart disease patients had bone loss of 4 mm or more distance from the CEJ to the bone, and 94% of subjects had 30% of sites measuring 4 mm or more of bone loss. High white blood cell counts were also associated with heart disease, but failed to differentiate those with and without periodontal disease. Control subjects with periodontal disease did have elevated white blood cell counts.

Clinical Implications: Perhaps in the future, blood tests will be requested for patients with periodontitis to determine C-reactive protein levels and white blood cell counts. Determining if these two markers can be lowered as a result of periodontal therapy will be the subject of future studies. Such findings may support the role of treating periodontal disease as a way to reduce the risk of heart disease.

Persson G., Pettersson T., Ohlsson O., Renvert S.: High-Sensitivity Serum C-Reactive Protein Levels in Subjects With or Without Myocardial Infarction or Periodontitis. J Clin Perio 32: 219–224, 2005.

Use diamond-coated ultrasonic inserts with caution

In 1952, Dr. A.B. Riffle published research in the Journal of Periodontology demonstrating the gouges and loss of root surfaces resulting from root planing with curets. That’s where the term “riffled root surfaces” or “riffling” comes from to denote the effects of over-instrumentation. As clinicians work to remove hard and soft deposits from root surfaces, care is also taken to minimize the damage and/or loss of root surface.

Diamond sonic and ultrasonic inserts are designed to increase speed and efficiency of mechanical instrumentation and have been shown to be substantially faster for treating furcations. Researchers at Louisianna State University compared Dentsply diamond-coated inserts, Dentsply P-10 inserts and Gracey 11-12 curets on 48 extracted, single-rooted teeth. Each instrument was used on three teeth and then replaced with a new instrument. The instruments were locked in place and the extracted teeth were held in a device that moved them back and forth at a constant pressure and distance against the tip being tested. Each tooth surface received three separate 10-stroke intervals with the assigned instrument. Root surface measurements were taken before and after each 10-stroke interval.

No differences were observed at any of the stroke intervals between the P-10 insert and the Gracey curets. For each micromillimeter of root surface removed by the P-10 insert and the curets, the diamond-coated inserts removed 5 micromillimeters of root surface. The P-10 tip left the smoothest surface, followed by the curet. The diamond-coated insert left a very rough surface.

Clinical Implications: Diamond-coated ultrasonic inserts are effective for removing deposit and planing roots, but must be used with extreme caution for very short applications as they will remove root structure and create significant roughness.

Vastardis, S., Yukna, R., Rice, D., Mercante, D.: Root Surface Removal and Resultant Surface Texture with Diamond-Coated Ultrasonic Inserts: An In Vitro and SEM Study. J Clin Perio 32: 467-473.

Doxycycline gel found safe and effective

A new, not yet marketed, 14% doxycycline gel was tested to determine both clinical effectiveness and possible resistance. This multi-center study was conducted in early 2000 and involved patients at the Johann Wolfgang Goethe University in Frankfurt, Germany, the University of Heidelberg, Germany, and the University of Nijmegen in the Netherlands. A total of 110 patients with three single-rooted teeth, each having moderate periodontal disease, were treated. The teeth had to have bleeding and probing depths 5 mm or more. Since each tooth received a different treatment, no adjacent teeth were included in the study. Data were collected at baseline and again at three and six months. All teeth received a different treatment protocol: 1) scaling and root planing, 2) scaling and root planing plus the doxycycline gel, and 3) scaling and root planing plus a placebo gel. The test and placebo gels were both made by Ivoclar Vivadent, in Liechtenstein.

Using local anesthesia, scaling and root planing with hand instruments was limited to 10 minutes per tooth. Oral hygiene instructions were stressed, but patients were cautioned against doing any interpoximal cleaning for one week after gel placement. Good healing was observed for all groups at three and six months. Pocket depths were reduced 2.5 to 3 mm, bleeding upon probing was reduced by 40 to 64%, attachment level gains were 2 mm, and plaque and gingivitis levels were also improved. Healing was slightly better in the doxycycline gel group.

Four species of subgingival bacteria were monitored: Actinobacillus actinomycetemocomitans (Aa), Treponema denticola (Td) Tannerella forsythensis (Tf), Porphyromonas gingivalis (Pg). At both three and six months all bacterial levels were lower than baseline. Numbers for the doxycycline group were the lowest after treatment, but the placebo gel produced similar results. Although showing good results clinically and less bacteria in the pockets at the end of the study compared to baseline, the scaling and root planing group had higher subgingival bacteria counts than the two gel groups. No bacterial resistance was measured.

Clinical Implications: There may soon be another doxycycline local drug delivery product on the market from Ivoclar.

Eickholz, P., Kim, T., Bürklin, T., Schacher, B, Renggli, H., Schaecken, M., Holle, R., Kübler, A., Tarka-Krüger, P.: Non-Surgical Periodontal Therapy With Adjunctive Topical Doxycycline: A Double-Blind Randomized Controlled Multicenter Study. J Clin Perio 29: 108-117, 2002.

Ratka-Krüger, R., Schacher, B., Bürklin, T., Böddinghaus, B., Holle, R., Renggli, H., Eickholz, P., Kim, T.: Non-Surgical Periodontal Therapy With Adjunctive Topical Doxycycline: A Double-Masked, Randomized, Controlled Multicenter Study. II. Microbiologcal Results. J Perio 76: 66-74, 2005.

Pain associated with ultrasonic and sonic tip movement similar

Patients are interested in improved oral health from periodontal treatment, and also want less painful means of accomplishing that health. Air-powered sonic scalers work with an elliptical pattern of movement that produces a hammering motion. This motion is seen as an advantage over the linear motion of ultrasonic scalers as it allows more freedom for instrument positioning. However, the linear motion produces a scaping pattern which is thought to be more comfortable for patients than the hammering motion.

Researchers at the University of Greifswald, Germany compared an air scaler and a piezoelectric ultrasonic scaler to determine pain experienced by the patients. Seventy-four patients participated, each receiving treatment on three lower anterior teeth with the KaVo SONICflex 2000 and the other three lower anterior teeth with the EMS PiezonMaster 400. Treatment with each instrument was limited to two minutes. Any calculus remaining after the timed sessions was removed at the end of the study. All teeth were polished at the end of the study as well.

Patients completed a visual analog scale to express pain felt with each instrument. The horizontal line was graduated from zero for “no pain” to 10 for “unbearable pain.” No differences were observed between the two instruments for “perceived pain.” The majority of scores ranged from 1 to 3. The motion of the power scaler tip did not influence pain experienced by the patients in this study.

Clinical Implications: Beware of advertisements that suggest a “hammering” motion for power scaler tips leads to more pain. These findings suggest that the tip motion does not influence pain perception.

Kocher, T., Rodemerk, B.k Ganghänel, J., Meissner, G.: Pain During Prophylaxis Treatment Elicited by Two Power-Driven Instruments. J of Clin Perio 32: 535-538, 2005.

Instrumentation and polishing reverse Class I recession

Researchers at the University of Torino in Italy tested out the theory that instrumentation and polishing could induce the gingiva to creep back over the root surface, thus reducing the recession. Two case studies were previously reported, and this was the first controlled, randomized study to measure the reversal of recession following instrumentation. Twenty-four healthy, non-smoking adults between the ages of 19 and 33 participated in the study. Each subject had bilateral, Class I facial recession on incisors, cuspids or premolars. Prior to beginning the study, all subjects received oral hygiene instructions including the Modified Bass technique, using a soft toothbrush and flossing with unwaxed floss. Subjects needed to achieve a score of less than 20% of surfaces with plaque and bleeding before participating in the treatment.

With the toss of a coin, subjects were assigned the test treatment on one tooth and the control treatment on the other. The test treatment consisted of instrumentation with mini Gracey curets and polishing with a mini cup twice a month for two months and then every two months for the next 10 months. The control teeth received only polishing at the same visits.

After one year, recession was reduced on the teeth that received instrumentation and polishing from an average of 1.64 mm to 0.78 mm, a reduction of 0.86 mm. Twenty-one of the 24 test defects experienced a creeping attachment. Six achieved complete root coverage, 11 gained 50%-75% coverage, and three remained the same. Sites treated with only polishing experienced an average reduction of only 0.09 mm. In this group, 15 sites were unchanged, eight had a slight reduction in recession, and one site got worse.

The instrumentation reduced the convexity of the root surface and the mesial-distal distance, thus allowing the marginal tissue to creep. Creating a flat, plaque-free surface allows for easy regrowth of the tissue.

Clinical Implications: Recession of 2 mm or less can be treated non-surgically by hygienists with curets, polishing and good oral hygiene. Document the recession and treat and monitor levels over the following year to see if the gingival margin creeps back over the root surface.

Aimetti, M., Romano, R., Peccolo, D., Debernardi, C.: Non-Surgical Periodontal Therapy of Shallow Gingival Recession Defects: Evaluation of the Restorative Capacity of Marginal Gingiva After 12 Months. J of Perio 76: 256-261, 2005.

CLASSIC STUDY
Being part of research motivates subjects to perform better

From 1924 to 1927, research was conducted at the Western Electric Company Hawthorne Works in Chicago to evaluate the effect of illumination on worker efficiency. Rather than demonstrating a correlation between room light and productivity, the study showed worker efficiency increased simply by participating in the research. This has become known as the “Hawthorne Effect.”

The first experiment compared three departments exposed to room illumination increased at different rates. One department showed fluctuating production, and the other two departments showed production increases seemingly independent of the increase in illumination.

To control for differences in work and workers, the second experiment was conducted in a single department with workers of similar age and experience. A control group was established which worked under standard illumination, and the test group worked under variable illumination intensity. Results for both groups showed a steady and nearly identical increase in production.

Thinking that the combination of natural and artificial light might have influenced the first two experiments, the third experiment tested only artificial light. The control group worked under constant light of 10 foot-candles, while the test group started at 10 foot-candles and decreased in one foot increments to three foot-candles, at which time workers protested and production decreased. However, production had steadily increased for both groups until a level of three foot-candles had been reached in the test group. One-foot candle is the amount of light produced by a standard candle at a distance of one foot.

In a final experiment with just two workers, light was increased daily and the workers were asked for their opinion, which was positive. The light was then kept constant, but the workers saw maintenance men change the light bulbs and were told the light was being further increased. The workers responded favorably to what they perceived as an increase. This was repeated with decreasing light, followed by a steady light and again telling the workers it was being decreased, again with similar results.

Clinical Implications: The phenomenon of improvement simply because of participation in a research study — the “Hawthorne Effect”— is often apparent in oral hygiene studies. When comparing toothbrushing alone to brushing and flossing, improvement in the control group, which is instructed to brush as usual, has been reported to be up to 35%. Improvement related to the fact that subjects are part of a study and their actions will be evaluated may account for up to 35% of the improvement in that group.

Roethlisberger, F., Dickson, W: Management and the Worker, Harvard University Press, 1939.