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.

Classic Study
Debridement focus shifts from calculus to plaque
Appeared in Perio Reports in 1993

Before 1980, complete cementum removal was thought necessary in order to remove “cementum-bound endotoxins.” Since then, studies have found the endotoxins easily removed using only rubber cups and brushes. A two-year study reported in the Journal of Periodontology in1988 by Nyman and co-workers found no clinical differences in healing between a group in which the cementum had been removed by instrumentation and a group receiving only rubber cup polishing and careful removal of calculus to preserve underlying cementum.

In a current study, researchers in Switzerland used a microscope to evaluate plaque removal following polishing with rubber cups and plastic points. The study included four patients with 10 single-rooted teeth, providing 40 surfaces for evaluation. Following flap reflection, the root surfaces were polished with prophy paste, using rotating rubber cups and reciprocating plastic points. Treatment time averaged three minutes per tooth. The teeth were extracted following treatment and evaluated using a scanning electron microscope.

Small islands of plaque were measured on the 13 calculus-free surfaces. These small islands measured less than 0.4 mm x 0.4 mm. Plaque was also present along the periphery of calculus deposits, as well as occasionally being detected in depressions on the rough calculus surfaces. Almost complete plaque removal was possible using rubber cup polishing. These findings may explain the healing described in Nyman’s study. Such findings shifted the focus of subgingival debridement from calculus removal to plaque removal.

Clinical Implications: The ultimate goal of instrumentation is tissue health. Removal of bacterial plaque and calculus are essential, while cementum removal is no longer considered necessary.

Schwarz, J., Rateitschak-Plüss, E., Geggenheim, R., Düggelin, M., Rateitschak, K.: Effectiveness of Open Flap Root Debridement With Rubber Cups, Interdental Plastic Tips and Prophy Paste. J Clin Perio 20: 1-6, 1993.

Cementum removal not necessary for healing

More than a decade after the classic study reported above, researchers today are still adding to those findings with new evidence. In this study, researchers in Brazil compared two procedures: traditional instrumentation including intentional cementum removal, and simply removing the calculus deposits and brushing the root surfaces with saline. Both procedures were carried out on anterior teeth using open-flap access. Each of the 40 test subjects had at least two anterior proximal sites measuring 5 mm or more.

All patients received supragingival ultrasonic instrumentation and oral hygiene instructions. Instead of the traditional periodontal probe, a round-tip steel wire with a rubber stop was customized for each patient and a caliper used to measure distance. The wire was inserted subgingivally and the distance from the base of the pocket to the rubber stop was measured. The distance from the rubber stop to the gingival margin was also recorded. Probing depth was determined to be the difference between the two measurements. The researchers did not discuss their decision to use a wire instead of a calibrated probe.

Subjects underwent a four-week oral hygiene instruction period before instrumentation was performed. Subjects were randomly assigned to one of four groups: 1. instrumentation with Gracey curettes to remove calculus and cementum, until the surface was glassy smooth; 2. ultrasonic instrumentation with the same goal as the first group; 3. calculus removal with Gracey curettes with no attempt to remove cementum and polishing with saline for 60 seconds; 4. ultrasonic instrumentation to remove deposits only, followed by polishing with saline for 60 seconds. All instrumentation was done using a surgical microscope.

Following instrumentation, flaps were closed and sutured. Subjects were instructed to rinse with chlorhexidine twice daily for 30 days. Following suture removal seven days later, subjects were instructed to resume regular oral hygiene. Subjects were seen every two weeks for professional polishing during the entire four-month study.

All four treatment approaches resulted in significant reductions in probing depths, from 6-7 mm to 2 mm. More recession was observed following ultrasonic scaling.

Clinical Implications: Removal of calculus and bacterial biofilm are essential for tissue healing. Removal of cementum provided no added benefit in this study.

Sallum, A., Alves, R., Damis, L., Bertolini, P., Nociti Jr., F., Sallum, E.: Open Flap Debridement With or Without Intentional Cementum Removal: A 4-Month Follow-Up. J Clin Perio 32: 1007-1010, 2005.

Ultrasonic instrumentation effective with either FM or quadrant approach

Full-mouth debridement (FMD) provides an alternative to the traditional quadrant approach to periodontal instrumentation by offering an option for patients who prefer one long visit rather than four shorter visits.

It was thought that by debriding the entire mouth within 24 hours bacterial transmission from diseased sites to treated sites would be reduced and therefore lead to greater healing. Not all studies have confirmed that finding. The additional use of chlorhexidine as a disinfectant following instrumentation did not result in greater tissue healing.

Recently, researchers at the Tokyo Medical and Dental University focused on ultrasonic instrumentation when comparing single visit and four quadrant debridement visits. Three treatment protocols were tested on three groups of 12 patients each with moderate to severe periodontitis: FMD with 1% iodine lavage, FMD with water lavage, and four quadrant visits using the ultrasonic scaler with water irrigation. The ultrasonic scaler used was an EMS Piezon® Master 400. All subjects received oral hygiene instructions and monthly prophylaxis visits following assigned treatment.

The group receiving iodine lavage with ultrasonic instrumentation was also instructed to rinse twice daily with 0.05% chlorhexidine for the first month following treatment, and to include tongue brushing daily.

All three treatment groups demonstrated significant healing at the three- and six-month exams. Probing depths 5 mm and deeper showed average reductions of 3 mm and gains in clinical attachment of 2 mm. Total treatment time was less for the FMD groups compared to the quadrant group: two hours and 15 minutes compared to three hours. No elevated body temperature was noted for any of the subjects following treatment. Patients responded well to all three approaches. The addition of iodine in the ultrasonic lavage did not provide any additional benefit.

Clinical Implications: Both full-mouth and quadrant approaches to debridement therapy can reduce disease and improve periodontal health. Consider your skill level as well as patient comfort, wishes and scheduling options when making treatment decisions.

Koshy, G., Kawashima, Y., Kiji, M., Nitta, H., Umeda, M., Nagasawa, T., Ishikawa, I.: Effects of Single-Visit Full-Mouth Ultrasonic Debridement Versus Quadrant-Wise Ultrasonic Debridement. J Clin Perio 32: 734-743, 2005.

Chlorhexidine varnish may be our next local drug delivery system

Chlorhexidine (CHX) varnish is used for caries prevention and now is being considered as an adjunctive subgingival antimicrobial used in combination with scaling and root planing. Researchers at the Free University of Brussels, Belgium, conducted a pilot study to determine if CHX varnish enhances periodontal healing.

The CHX varnish EC40® (35% CHX) is produced in the Netherlands. It is applied with a syringe and has a contact time of 15 minutes.

By contrast, PerioChip® remains in the pocket seven days.

All patients received two-stage scaling and root planing, with half the mouth treated at each visit, one week apart. Baseline probing depths were recorded after the instrumentation, rather than before, which can lead to overestimation of healing.

Findings showed the CHX varnish sites experienced an additional millimeter of probing depth reduction and an additional millimeter gain in clinical attachment level. Average treatment time was five minutes per tooth for both test and control groups. Deep pockets showed probing depths reduced by 3 mm in the control group and 4 mm in the CHX group, but these figures are probably exaggerated due to baseline measurements being taken after scaling and root planing. The results look promising, and now further studies are needed to confirm these findings before this varnish is introduced for use in clinical practice.

Clinical Implications: Chlorhexidine varnish is not yet available in the U.S., but may be introduced in the future. It would be interesting if there were a study comparing the chlorhexidine varnish with a placebo varnish, to see if the varnish itself has any effect.

Cosyn, J., Wyn I., Rouck, T., Sabzevar, M.: A Chlorhexidine Varnish Implemented Treatment Strategy for Chronic Periodontitis. J Clin Perio 32: 750-756, 2005.

CRP levels lowered six-months after non-surgical therapy

Serum C-reactive protein (CRP) is a liver protein that is increased as inflammation increases. Systemic inflammation due to chronic infection is considered a risk factor for atherosclerosis, or hardening of the arteries. The evidence is pointing at H. pylori, C. pneumonia, and cytomegalovirus as three very likely infective agents. Periodontal researchers are also looking at periodontal infections involving T. forsythus, P. gingivalis, and Aa.

Researchers in England treated a group of 94 subjects for severe, generalized periodontitis. A periodontal graduate student provided non-surgical therapy using only an EMS piezo-electric scaler under local anesthesia. All subjects received oral hygiene instructions. Data collection was done at baseline, two months and six months, and included clinical indices, subgingival microbial samples, plus blood was drawn for CRP levels and to extract DNA from leukocytes for identification of proinflammatory cytokines Interleuken-1 and Interleukin-6.

Subjects began the study with average plaque scores of 58%, bleeding 64% and a total of 77 pockets (4 mm and deeper). At the end of the study plaque scores averaged 21%, bleeding 16% and the average number of pockets was 28. Pocket depths were reduced approximately 1.2 mm.

Normally, there is no CRP in the blood. Specific polymorphisms of IL-6 were associated with the highest baseline levels of CRP – 3.2 mg/L. The average baseline score for polymorphisms of IL-1 was 2.9 mg/L. CRP levels were lower by the end of the study for subjects who showed the greatest healing; defined as having less than 30 pockets 5 mm or deeper and a bleeding score less than 30%.

Clinical Implications: Severe generalized periodontitis results in systemic inflammation as measured by CRP levels. Treatment of these cases results in reduced CRP levels. This may reduce risk of atherosclerosis as well. More research is needed.

D’Aiuto, F., Mohammed Parker, M., Andreou, G., Brett, P., Ready, D., Tonetti, M.: Periodontitis and Atherogenesis: Causal Association or Simple Coincidence? A Pilot Intervention Study. J Clin Perio 31: 402-411, 2004.

Can rinsing reduce herpes virus spread?

The herpes lesion itself is considered the primary source of disease transmission. During the prodromal stage and through the life of the active viral infection, virons or the spaceships that carry the virus to various parts of the body, are shed in the saliva, and can be measured during an outbreak.

Researchers at the University of Maryland measured herpes virons in the saliva following a 30-second rinse with either Cool Mint® Listerine® or sterile distilled water. All 92 study subjects presented with prodromal signs of an oncoming lesion or a lesion in stage 1 or 2. The area or the lesion was swabbed and laboratory tests confirmed the presence of the herpes virus for each study subject. Saliva samples were taken prior to rinsing and again 30 seconds later, 30 minutes later and 60 minutes after rinsing.

Cool Mint Listerine reduced the virons to nearly zero at 30 seconds and remained low for 30 minutes and then returned to baseline levels at 60 minutes. The 30-second rinse with sterile distilled water reduced the virons only slightly and by 30 minutes scores were back to baseline levels.

Clinical Implications: Rinsing with Cool Mint Listerine may reduce aerosol cross-contamination of the herpes virus for a period of 30 minutes. This is a preliminary study and more testing needs to be done before claims of actual protection against viral cross-contamination can be made.

Meiller, T., Silva, A., Ferreira, S., Jabra-Rizk, M., Kelley, J., DePaola, L.: Efficacy of Listerine® Antiseptic in Reducing Viral Contamination of Saliva. J Clin Perio 32: 341-346, 2005.