Oral Health Group

Managing Refractory Periodontal Disease Using the Periodontal Summary Score

October 1, 2006
by Cary Galler, DDS, MSD

Despite the best therapeutic efforts by dental professionals to treat periodontal disease, some patients do not respond as well as expected. These cases appear resistant to treatment and as such, these patients are deemed to exhibit Refractory Periodontitis.1 The nature and pathogenesis of Refractory Periodontitis are not yet clearly understood. It is likely that factors involving the microbiological and host immune response are implicated in the progression of the disease.2 A diagnosis of Refractory Periodontitis is only appropriate in those patients who adequately comply with recommended oral care measures, attend for regularly scheduled periodontal supportive care at prescribed intervals and demonstrate a decline in their periodontal health, as evidenced by the appearance of clinical signs and symptoms. It is imperative that dental professionals clearly identify those patients who are not responding to conventional treatment in the expected manner, so that appropriate adjustments to that patient’s treatment regimen can be provided.

The Periodontal Summary Score (PSS) has been proposed by this author as a relevant periodontal assessment tool to assist dentists and dental hygienists in evaluating the current status of a patient’s periodontal disease and to improve periodontal case management.3 The PSS enhances the diagnostic value of a standard Periodontal Examination Record by adding line and summary scores into the record to compute important periodontal signs. Considered collectively and longitudinally, the summary scores signal the presence or absence of periodontal disease activity. By quantifying the number of sites with probing depths greater than 3.0mm and equal to or greater than 6.0mm, as well as the number of sites which bleed upon periodontal probing into a concise and easily understandable PSS, an analysis of the multiple readings from the Periodontal Examination Record may be simplified and brought into distinct focus. When data comparisons are performed of several PSSs taken at separate appointment intervals, the clinician may readily determine if a patient’s risk profile has changed, thereby identifying when new treatment strategies may be indicated (Figs. 1 & 2).


Scientific studies reveal the association between periodontal probing depth, gingival inflammation and periodontal disease progression.4 It is incumbent upon the dental professional to recognize when clinical factors indicate the presence of active or refractory periodontal disease and to initiate interventive treatment measures which will counteract disease progression. When the PSS is computed from a charting session, it summarizes the most relevant factors associated with periodontal risk, i.e. probing depths and gingival bleeding. Changes in the PSS may serve as a valuable reference to guide the clinician in managing periodontal disease.

Data for numerous periodontal studies indicate that the continued absence of gingival bleeding on probing is an excellent predictor of periodontal stability.5-8 The loss of clinical attachment, as evidenced by probing depth increase, is commonly cited as a basis to predict the progression of periodontal disease.9,10 Studies have been reported to demonstrate that the presence of deep pockets and gingival bleeding is undesirable and may be a predictive of the progression of periodontal disease.11,12 The PSS provides an easily identifiable mechanism to facilitate the clinician’s ability to discover changes in periodontal signs of probing depth and gingival bleeding. In this way, the clinician may promptly counteract any new clinical manifestations by initiating appropriate changes to the therapeutic regimen (Figs. 3A-C & Tables 1 & 2).

When evidence is revealed by the PSS that periodontal disease is active in the treated or untreated individual, there are a number of treatment options available to the clinician. This paper will discuss some of the most valuable strategies that a clinician may consider in managing active or Refractory Periodontitis (Table 3).


Scaling and root planing has been shown to be a most effective method in treating chronic periodontitis.13-14 It is evident however, that after a period of time, bacterial levels may rebound, manifesting in a return of clinical symptoms of gingival bleeding, inflammation, attachment loss, and pocket depth increase.15-17 This clinical reversal requires the clinician to be highly vigilant in monitoring a patient’s clinical progress, so that any return of periodontal signs of disease may be promptly counteracted by the initiation of appropriate interventive treatment strategies. When new episodes of periodontal activity become evident, a sound strategy, as a first line of defence, may be to provide a thorough circuit of scaling and root planing with the use of local anesthetic, if required for patient comfort.

There have been reports that full mouth disinfection by scaling and root planing performed by two, two hour sessions scheduled within twenty four hours may provide additional therapeutic benefit over partial mouth disinfection where root planing is performed one quadrant at a time at two week intervals.18-20 The efficacy of a full mouth approach has not been conclusively substantiated.21 Such approach, however, offers the clinician an alternative method to managing refractory periodontal patients using scaling and root planing as a therapeutic method.


A periodontal maintenance interval of three months for patients with a history of periodontal disease appears to be effective in supporting periodontal health.22 This relates to a time period of 9-11 weeks for periodontal pathogens to repopulate to pre-treatment levels.23 This interval may not be satisfactory without good patient compliance.

Patients whose recare frequency is greater than three months may require an adjustment to their recare frequency, particularly if clinical signs of periodontal disease become evident. Comparative analysis of the PSSs available in a patient’s record will guide the clinician in determining a suitable recare frequency. In addition, smoking appears to exacerbate the periodontal risk24 and may suggest the need for a tighter recare schedule. The PSS will greatly assist in determining if changes in the recare interval alone render improvements to periodontal stability, or if additional treatment strategies may be indicated (Tables 4 & 5).


When a patient shows inadequate improvement in his/her periodontal state following a normal course of periodontal treatment, these clinical changes may be identified by noticing upward trends in the PSS. As the score creeps higher, a patient’s periodontal condition demonstrates progressive instability and further clinical manifestations may become evident. A referral to a periodontal specialist may offer the patient an expanded realm of treatment options which may prove to be more effective in counteracting the presenting problems.

Often, periodontal surgery may be appropriate to reduce probing depths and to provide the patient with an increased ability to access difficult to reach areas which would otherwise be impossible to maintain.25 Studies indicate that probing depth reductions by way of periodontal surgery may be beneficial in enhancing tooth longevity.26-29 Where ongoing periodontal support indicates that there is minimal progress in stabilizing periodontal disease activity, a referral to a periodontal specialist for assessment and possible treatment, including surgical care, may be the responsible course of action.


As periodontal disease is fundamentally a microbiologically mediated disease, the administration of a systemic antibiotic is of value to reduce bacteri
al loads and to promote periodontal health for patients who do not respond to conventional therapy. The administration of antibiotics for the treatment of chronic and refractory periodontitis should follow accepted pharmacological principles including, when appropriate, identification of pathogenic organisms and antibiotic sensitivity testing. Most periodontal pathogens are Gram-negative anaerobic rods. Some pathogens are Gram-positive facultative and anaerobic cocci and rods, while others are Gram-negative facultative rods.30

Recurrent or Refractory Periodontitis is often related to the persistence of subgingival pathogens or to impaired host resistance. The most common recommended regimens utilize monotherapy administrations of Doxycycline, Clindamycin, Metronidazole or Ciprofloxacin, or with a combination of Metronidazole and Amoxicillin or Ciprofloxacin. A course of systemic antibiotics during a period of periodontal exacerbation may reverse the periodontal activity and render the condition into temporary or permanent remission.

Although the use of a systemic antibiotic has proven to be an effective adjunctive measure in managing acute and chronic periodontitis, its administration is beset by problems of bacterial resistance, gastrointestinal disturbance and allergenic reactions. Emerging new strategies are now evident that avoid the serious drawbacks that systemic antibiotic administration present. The concept of host modulation therapy, using sub-antimicrobial doses of doxycycline in combination with scaling and root planing, has been identified as an important new method in treating Refractory Periodontitis.


Although the pathogenesis of periodontitis is initiated by periodontopathic bacteria within the gingival sulcus, new well documented evidence based data indicates that periodontal destruction is also caused by the response of the host to the presence of the bacteria, manifesting in the release of cytokines and matrix metalloproteinases (MMPs). We now better understand that it is the host tissues (the patient’s own tissues) that degrade connective tissue, resulting in attachment loss, bone destruction and progression of periodontitis.31-34 By modifying the host response, clinical outcomes may be enhanced. This novel approach represents a new and distinct line of defence and in combination with biomechanical therapy (scaling and root planing, surgery, adjunctive measures) may promote additional therapeutic benefit resulting in a reduction of gingival inflammation, bleeding probing depths and a gain in clinical attachment levels. Periostat, a low dose 20mg. Doxycycline formulation taken twice daily, therefore, is an important new therapy to combat against Refractory Periodontitis when used as an adjunct to scaling and root planing. This low dose doxycycline, part of the tetracycline family does not create bacterial resistance.35

On a clinical basis, when a patient presents for periodontal evaluation after the completion of initial periodontal therapy, including scaling and root planing, and there continues to be persistence in gingival bleeding and/or gingival inflammation, the introduction of a six to nine month therapeutic regimen of Periostat to suppress enzymatic activity is indicated. This treatment approach has been shown to have a particular benefit in smokers, where signs of gingival bleeding are often masked by the smoking36,37 (Figs. 4A-C).


If a patient shows periodontal progression which is limited to a low number of sites, localized antibiotic delivery may be an excellent therapeutic method to arrest or reverse these problems. Presently, Atridox, a Doxycycline Hyclate based bioabsorbable gel formula is the only localized slow release agent approved for use in Canada.38 It may be used as a monotherapy or in combination with scaling and root planing. The advantage of this treatment method is that it delivers a high dose of concentration of agent directly to the site, while avoiding the drawbacks of systemic administration.39-41

Atridox has a very detailed research base and has been shown to promote probing depth reduction in the order 1.5mm – 4mm and clinical attachments gain of 1.0mm.42-45 The advantage of Atridox is its capacity to release into the crevicular fluid a high concentration of antibiotic (940 times higher than that achieved by a systemic antibiotic) for a period of seven to 10 days, thus providing very effective kill of bacteria in its path. Atridox also does not result in bacterial resistance.46 The combination of scaling and root planing and Atridox is an effective therapy to use at sites that do not respond to conventional therapy. Furthermore, the combinations of Atridox, Periostat and scaling and root planing had significantly superior results to scaling and root planing alone. It is evident, therefore, that these combined modalities should be considered for use when a refractory periodontal site is encountered47 (Figs. 5A-C).


Recently, Periowave, a system for photodynamic disinfection was launched in Canada. This technique uses a non-thermal diode laser which is absorbed into a photosensitizing solution that is irrigated into the subgingival environment.48-50 The activated photosensitizing solution, which is muco-adherent, attaches to the cell wall of the bacteria, creating a free radical of oxygen and through the peroxidation of lipids, ruptures the bacterial cell wall. Being photodynamic in nature rather than a systemic antibiotic, it does not result in bacterial resistance. Periowave kills bacteria associated with periodontal infection. By inactivating virulence factors, an environment conducive to periodontal healing may be promoted.

Photodynamic disinfection results in enhanced periodontal healing, as evidenced by an increase in clinical attachment levels, a reduction in probing depths and a decrease in bleeding on probing, as witnessed in the Loebel study.50 This pilot study used a sample of 622 diseased sites from 15 test patients being monitored for a period of 12 weeks. Further confirmative evidence is required from larger sample sized, randomly controlled, double blinded, multi-centered studies to corroborate the early clinical data. If the results can be substantiated, the concept of photodynamic disinfection may represent an interesting new modality of therapy (Figs. 6A & B).


When treatment measures fail to arrest the progression of periodontal disease, the extraction of the affected tooth may predictably solve the periodontal problem. The replacement of this tooth can be considered if sufficient alveolar support remains to facilitate the satisfactory integration of a root form analogue into the existing alveolar housing. Often, however, a delay in dealing with the periodontal problem results in excessive loss of alveolar support, reducing the chances for successful implant integration without prior or concomitant bone augmentation. A paradigm shift in treatment decision making has resulted, causing clinicians to now consider if it is best to treat a guarded or poor prognosis periodontal situation, or rather to extract the tooth and deal with a more predictable replacement by way of an osseointegrated implant. Implant therapy, therefore, has radically altered our cognitive perspective in treating advanced or refractory periodontal cases.


In using the PSS as a diagnostic assessment guide, a target score of 10-0-10 has been proposed as a threshold below which a patient may be assumed to exhibit periodontal health.3 Periodontal patients may demonstrate a few random sites of limited probing depth increase or gingival bleeding, but these should be isolated and of low magnitude. As a result, on an empirical basis, it may be reasonable to accep
t up to 10 sites of probing depth greater than 3.0mm but not equal to or greater than 6.0mm, with up to 10 sites which bleed upon probing. Such cases most commonly demonstrate relatively excellent periodontal health and may be managed without difficulty, if the patient is on a regularly scheduled program of periodontal supportive care. It is when changes in periodontal activity result, as evidenced by an increase in the PSS, that the clinician should become particularly vigilant about protecting his/her patient against further disease progression (Table 6).

In practical terms, the PSS acts as a valuable assessment aid to alert the clinician when a patient’s periodontal profile undergoes change. This is when new treatment strategies should be contemplated. Clinical acumen and experience should dictate how this is best performed. The treatment choices cited in this article offer the most currently valuable and reliable approaches to resolving Refractory Periodontitis.

A PSS which increases consistently over a period of time indicates a need to change the treatment status quo. When this occurs, new treatment approaches should be conceived. The efficacy of the new treatment regimen should then be evaluated longitudinally over time to determine if a satisfactory response to the new approach has resulted. An increasing PSS summons the clinician to act, as it highlights the need for further care. The closer the clinician can bring the Periodontal Score to the proposed target value of 10/0/10, the more likely the success of a patient’s periodontal disease management.

Dr. Galler practices in Toronto, ON. He is the Co-Director of the Periodontal Plastics Research Centre at the Discipline of Graduate Periodontics, Faculty of Dentistry, University of Toronto. He is a founding director of the Ontario Dental Hygiene Study Club and the North York Center for Dentistry as well as mentor to the North York Dental Study Club.

He wishes to express his sincere appreciation to Sue Tsoraklidis, Lisa Cahill, Katie Sutherland and Marlo Galler for their very valuable contribution to the preparation of this article.

Dr. Galler would be pleased to forward a fresh copy of the Periodontal Examination Record to any dental team member that would like to incorporate the Periodontal Summary Score within their practice. Please contact sue@drgaller.com to have the file e-mailed to your practice.

Oral Health welcomes this original article.


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