by Trisha O'Hehir
The patient came in with four- to six-millimeter pockets in the posterior interproximal areas and no problems in the anterior. Not surprising, since the patient only brushed and didn't clean between his teeth. Your instructions stressed to the patient that he should start cleaning in between rather than brushing first.
The patient is now back for his first maintenance visit since you completed thorough scaling and root planing - better known today as debridement therapy. Using both power and hand instruments, you spent time removing subgingival calculus and flushing out bacterial biofilm. Checking with both a probe and an explorer, you judged the surfaces to be smooth and free of deposits. Sure, the research says we can't always feel the calculus, but smoothness was all you had to go on when you decided your finishing point.
Now, several weeks later, you're expecting to see healing in those interproximal areas. Instead, several areas are still six millimeters deep and still bleeding. Oh, how frustrating! This calls for detective work. Start asking questions.
Why didn't the tissue heal? Why is there still bleeding? Is it new infection, reinfection, or infection that wasn't eradicated? Was the instrumentation inadequate? Is the patient's immune response compromised or are there other risk factors involved? What's the answer?
It's easy to point at the patient and claim poor oral hygiene. But in this case, it actually looks better than when he began treatment. Besides, you can't expect a patient to deplaque down six millimeters. Tools to predictably do that on a daily basis are not yet available. A stick with bristles and a piece of string are just too archaic. But you were smarter than that because you gave him interdental brushes.
Supragingival plaque does slowly move subgingivally, but for a six-millimeter pocket to remain infected, bacteria need to be at the base of the pocket. You might now consider daily oral irrigation with either a countertop irrigator or a shower or sink model. Flushing the pockets with water is effective in controlling the inflammatory response of the tissue. Although not a great way to remove plaque biofilm, the fluid irrigation seems to flush out the toxins that trigger the inflammatory response, and allows the tissue to heal.
Back to the question of why the pocket remains infected after treatment. Maybe bacteria remaining in the pocket wall reinfected the area. It's clear that bacteria are the key since bacterial toxins trigger the infection. Individual bacteria do use the tissue as a parking place. Organized biofilms have not yet been documented in pocket walls. If bacteria in the pocket walls were the source of infection, then soft-tissue curettage would eliminate that problem; however, no research shows that soft-tissue curettage alone eliminates infection. In a bleeding pocket, the epithelium remains ulcerated due to bacterial toxins opposite the tissue. Ulcerated tissue provides an opportunity for bacteria to enter the blood stream and travel to other parts of the body, thus the "perio-systemic link."
Here we have a Catch-22. Ulcerated tissue provides a greater source of nutrients to the bacteria so plaque regrowth will be faster there than in a healthy area. Based on bacterial plaque studies reported in 1973 by Dr. Saxton, plaque will reform on a clean tooth surface within three hours next to healthy tissue and within five minutes next to inflamed tissue. Dr. Alexander's research in 1969 showed that bacterial levels return to original levels 24 hours after cleaning. In an infected pocket, bacterial proliferation is progressing at a rapid rate. This information supports the need for thorough and immediate plaque control after debridement therapy. That's why so many periodontal
research studies include twice-daily rinses with chlorhexidine during the first few months after treatment. Control of the bacterial biofilm formation is critical.
What about your instrumentation technique? Did you miss some of the calculus? Unless you were using the magnification of Perioscopy(r), you most likely did. Research evidence indicates that clinicians nearly always miss some calculus. Instrumenting blind and judging effectiveness on touch is subjective. Some calculus feels very smooth, thus giving a false sense of instrumentation success. It's not just thin veneers of calculus that are missed. Research shows that calculus is often missed at the CEJ, and from my experience, just under the contact area. Instrumentation technique must be adjusted to reach these areas effectively. Be sure to check these areas for remaining deposits.
You're probably asking, "Why go after the calculus when the problem is bacteria?" You're right; calculus by itself does not cause periodontal disease. Subgingival calculus is actually the result of tissue infection, not the cause. It is the by-product of bacterial biofilm and tissue infection. Calculus by itself will not cause infection.
The bacterial biofilm remaining in or on the calculus is most likely the answer to why six-millimeter pockets and bleeding remain after thorough treatment. The remaining subgingival deposit forms a calculus hotel. Studies done on supragingival calculus show that bacteria do live in spaces inside calculus. Not all bacteria mineralize and form the hard structure of calculus. Some die without mineralizing, creating spaces in the calculus. These become rooms in the Calculus Hotel for viable bacterial biofilm.
In laboratory studies, researchers treated the outer surface of calculus to kill all bacteria and, yet, found live, viable bacteria inside the calculus. This finding was made with samples of supragingival calculus. More research is needed to determine if this is also true of subgingival calculus.
Biofilm attached to the root surface is easily removed with a power scaler and probably with the water forces of an oral irrigator. When the biofilm resides within a piece of calculus - safely tucked away in the Calculus Hotel - it is protected. Despite your tactile sensitivity, calculus will remain in some cases. The biofilm within the Calculus Hotel will be untouched and able to continue functioning as usual, dumping toxins into the pocket. In a 1986 review article on calculus, Drs. Mandel and Gaffar described calculus as a "toxic waste dump site." This is a good way to describe it to your patients.
If bleeding pockets remain after therapy, don't trust your tactile sense to find the calculus deposits. Instead, trust the tissue response that is telling you a calculus hotel full of bacteria remains. Reinstrument the surface and evaluate the tissue response in a week. Tissue response, not tactile sensitivity, will give you the answer.
Could it be a compromised immune system or other risk factors? Remember, you're dealing with a bacterial infection. Up to this point, there is no research that says the pocket wall can be ulcerated simply due to a compromised immune system or other risk factors. The bacteria still trigger the immune response. It's important to take those things into consideration, but they don't explain away pockets and bleeding. We do know that daily aspirin intake increases bleeding upon probing, but only in already infected sites, not healthy sites. A compromised immune system will mount a bigger response to bacteria than a normal immune system, but it won't create periodontal pockets by itself.
When you reassess a patient after treatment and still find pockets and bleeding, remember, you're dealing with a bacterial infection, triggered by bacterial biofilm in the pocket. Asking questions and finding answers will help you decide on further treatment or referral. You need to figure out why the area is still infected. Where are the bacteria being harbored? Can you access them? What can you do about them? Understanding the nature of this bacterial infection will help you figure out the best retreatment plan or referral for this person. Avoid the trap of "treating" these bleeding pockets with three-month maintenance visits. You know the science; you can figure out the cause of the infection and decide on further treatment or referral.
Trisha E. O'Hehir, RDH, BS, is a senior consulting editor of RDH. She is also an international speaker, author, instrument designer, inventor, and oral health detective. Her Web sites are www.perioreports.com and www.toothpastesecret.com. She can be reached at (800) 374-4290 or at [email protected].