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Scaling & Root Planing is Not the “Killer App” for Chronic Periodontitis

Posted: August 10, 2015

A systematic review (SR) on scaling and root planing (SRP) was published by the American Dental Association in July 2015. This addition of News2Use highlights aspects of the unabridged full systematic review (not published in JADA but available online) and the ADA Clinical Practice Guideline derived from it. Click here to review the unabridged SR and click on the link for “Full Report”.

Periodontal scaling and root planing per quadrant (CDT D4341), the stalwart of nonsurgical periodontal therapy, was compared to no treatment at all. The study also evaluated to determine if SRP combined with adjunctive horsepower performed better than SRP alone.

The SR revealed very interesting outcomes. SRP demonstrated miniscule and clinically irrelevant (0.36-0.62mm) improvements in clinical attachment levels (CAL): changes so small that they cannot be accurately measured or recorded in clinical practice. SRP combined with adjuncts (antimicrobials; antibiotics; subantimicrobial-dose doxycycline; locally delivered antimicrobials such as chlorhexidine chips, and Arestin®; and a variety of nonsurgical lasers) also resulted in very small improvement (0.2 – 0.6 mm). Of these 9 therapy protocols evaluated, 6 were cited with serious imprecision, 8 with inconsistencies, and none were reported to have a high level of certainty in the evidence.

In this SR, SRP was not compared to any below-the-gum line (subgingival) treatments that are routinely performed during dental cleaning appointments (e.g., removal/disruption of dental biofilms, calculus removal, debridement, subgingival scaling, and/or ultrasonic scaling). Nor was SRP compared to conventional multi-focal “Initial Therapy”, the approach that continues to be taught in dental education.

The authors discovered that “Many published papers did not define disease severity of the sample population…” and stated that confidence in the consistency of the diagnosis definitions that were provided for chronic periodontitis was limited. In this SR, slight disease was defined as 1 or 2 mm of CAL (clinical attachment level) loss, moderate as 3 or 4 mm CAL loss; and severe as greater than or equal to 5 mm CAL loss. However, this is not so much a definition of the “disease” chronic periodontitis as it is a description of the millimeter amount of vertical CAL loss. The “disease” periodontitis is more accurately defined as clinically detectable inflammation (e.g., bleeding upon gentle probing) superimposed on sites with CAL loss. Unfortunately, this SR does not indicate that the presence of clinically detectable inflammation is the essential feature of periodontitis. Furthermore, it should be noted that CAL loss is not pocket depth: it is the sum of vertical probing depth plus root exposure (distance between the gingival margin and the cementoenamel junction).

5mm (defined in this SR as Severe) CAL loss without clinically detectable inflammation is not the disease, chronic periodontitis. It is Periodontal Health on a Reduced Periodontium.

The ADA Clinical Practice Guideline

From this SR the authors collaborated, voted, and established the ADA Clinical Practice Guideline: Nonsurgical Treatment of Chronic Periodontitis by Scaling and Root Planing with or without Adjuncts. The Clinical Practice Guideline, like its underlying SR, does not indicate that the presence of clinically detectable inflammation is required for a diagnosis of periodontitis. This missing criteria coupled with describing disease only by severity of CAL loss may lead to clinical guideline misinterpretation or its use for unintended purposes. Two examples follow:


Consider the top recommendation: “For patients with chronic periodontitis, clinicians should consider scaling and root planing (SRP) as the initial treatment.” Therefore, using the guideline a patient with 1mm gingival recession and 2 mm sulcus depth (3mm CAL loss) without signs of clinical inflammation at any site can potentially be characterized as having moderate chronic periodontitis and “clinicians should consider scaling and root planing (SRP) as the initial treatment”. It should be pointed out that the SR considers SRP to be Periodontal Scaling and Root Planing per Quadrant (CDT D4341). It would be reasonable to consider Quadrant Scaling and Root Planing as overtreatment in such a clinical situation.


Consider the #2 recommendation: “For patients with moderate to severe chronic periodontitis, clinicians may consider systemic sub-antimicrobial dose doxycycline (20 mg twice a day) for 3 to 9 months as an adjunct to SRP with a small net benefit expected.” Therefore, using the guideline a patient with 1mm gingival recession and 4 mm sulcus depth can potentially be characterized as having severe chronic periodontitis. Especially for a patient without generalized bleeding upon gentle probing, it would be reasonable to consider that Quadrant Periodontal Scaling and Root Planing (CDT D4341) plus systemic sub-antimicrobial dose doxycycline (20 mg twice a day) for 3 to 9 months is overtreatment.

So What’s a Clinician to Do?

  1. Give careful consideration to the reported limitations of the unabridged SR Full Report and the ADA Clinical Practice Guidelines Chairside Guide derived from it. Both are available at the ADA Center for Evidence Based Dentristy website.
  2. Although dentistry is long overdue for a well-designed study comparing SRP to other nonsurgical subgingival instrumentation interventions commonly performed in clinical practice, there is sufficient evidence to continue to perform subgingival instrumentation as an essential component of periodic supportive therapy appointments. (See 6 below)
  3. Basic clinical principles remain unchanged and need to be emphasized in clinical practice. Examination is the critical prerequisite for diagnosis, and treatment (interventions) should only be considered after a proper diagnosis is made.
  4. Interventions should be based on the highest levels of evidence. These are patient-centered, focused on clinically relevant outcomes and based on the individual patient’s quality of life (QoL) concerns. Whenever it is clinically reasonable to do, interventions should be instituted in a step-by-step approach, starting with the most effective conservative measures.
  5. Use of practical working definitions/terminology can provide valuable assistance in communication and clinical decision-making. Pertinent periodontal examples include:
    • Vertical Clinical Attachment Loss: the amount of vertical damage in millimeters (probing depth + exposed root length) as measured with a periodontal probe. This is not a disease, but damage from all previous sources.
    • Horizontal Clinical Attachment Loss (furcation probing/invasion): the amount of horizontal damage as assessed with a furcation probe. For more information, go to our PerioAccess Publishing page and check out “Perio Access® Periodontal Examination Quick Reference Guide”.
    • Probing Depth: A habitat of bacteria that can trigger an inflammatory response in adjacent tissues. Deep probing depths (pockets) are therapeutic targets. Shallow probing depths are a desired goal because they are easier to maintain than deeper ones.
    • Gingivitis: Clinically detectable inflammation at sites without clinical attachment loss.
    • Periodontitis: Clinically detectable inflammation superimposed on sites with clinical attachment loss.
    • Periodontal Health on a Reduced Periodontium: Clinical attachment loss without clinically detectable inflammation. If a site with periodontal health subsequently develops clinically detectable inflammation, the diagnosis might be either:
      • gingivitis superimposed on a reduced periodontium, or
      • recurrence of periodontitis.

      It is impossible to be certain which diagnosis is correct. However, the diagnosis makes no difference in this case because the treatment is the same (i.e., enhanced oral hygiene practices, removal of tooth-accumulated biofilms and detectable calculus).

  1. Regarding subgingival instrumentation, dentistry still needs well-designed, patient-centered and clinically relevant studies that address critical issues such as indications, technique, purpose, and frequency. However, it is reasonable to consider the following:
    • Periodic subgingival biofilm removal/reduction especially in adults who have demonstrated clinical attachment loss is an appropriate preventive therapeutic goal.
    • Subgingival instrumentation at sites demonstrating redness and/or gingival bleeding is positively correlated with reduction of clinically detectable inflammation and is therefore recommended.
    • Clinically and/or radiographically detectable subgingival calculus should be removed.
  1. “Initial Therapy” remains the time-tested, classic multi-focal approach for the initial treatment of chronic periodontitis. The Parameters of Care published by the American Academy of Periodontology listed below continue to provide some valuable guidance:

George K. Merijohn, DDS

San Francisco periodontist George K. Merijohn practiced 28 years and is associate professor in postdoctoral periodontics at UC San Francisco and U Washington. He is appointed special expert to the California Dental Board; serves as a consultant to dental schools, clinicians, and the legal profession; and is on the editorial board of the Journal of Evidence-Based Dental Practice. Dr. Merijohn leads seminars and workshops at major dental conferences and is published in peer-reviewed journals with articles on mucogingival clinical decision-making, risk assessment, and the evidence-based approach. More about George >