Following my exploration of the key updates in the 2018 classification of periodontal and peri-implant diseases in Part 1, this article delves into the practical implementation of the classification, specifically as adapted by the British Society of Periodontology (BSP). The BSP's unique approach to staging and grading periodontitis patients adds a layer of simplicity to the diagnostic process, enabling dentists to quickly assess disease severity and complexity, potentially reshaping the approach to treatment and referrals. Let's unravel the BSP's implementation, offering insights into how this adapted classification addresses the longstanding challenge of diagnosing periodontitis in everyday dental practice.

The British Society of Periodontology’s Adaptation of the 2018 Classification

Some great things come from The United Kingdom of Great Britain and its people. Tea breaks, cricket, antibiotics, the World Wide Web, and (I argue) an effective implementation of the 2018 classification.1 Let us consider a case example (Figs 1-5) involving a new patient arriving at your office/practice. This example is pertinent because a long history of regular visits should already have diagnosed and addressed the patient’s periodontitis.

As part of your examination, you rapidly screen, looking for bleeding on probing (BOP), increased probing depths (>3mm), and, in doing so, have in seconds carried out a Basic Periodontal Examination (BPE).2 We can, for the moment, disregard discussing in detail the diagnosis and management of patients merely with no pockets, only BOP, plaque, and calculus – these are elementary (BPE codes 0/1/2). However, should you find shallow periodontal pockets of say 4 & 5mm (BPE code 3), in the absence of other concerning signs (mobility, widespread tooth loss, etc.), this example new patient would enter a cause-related therapy phase of treatment, prophylaxis – scaling, polishing, subgingival debridement of teeth with increased probing depths, oral hygiene training, etc.3 We re-evaluate this patient at 3 months, identifying hopefully a resolution of inflammation, pocket reduction, a decrease in BOP, etc. However, should you probe and measure pockets of 6mm and more (BPE code 4), promptly, the patient requires a full and comprehensive periodontal examination, and a full set of periapical radiographs.


Table 3: Basic periodontal examination (BPE) codes
Code Descriptor Management
0 Healthy Preventative treatment only
1 Bleeding on probing (BOP) OHI, plaque & debris removal
  • Calculus, supra & subgingival
  • latrogenic marginal irritations
OHI, subgingival plaque & calculus removal, refine restoration margins where possible


  • Shallow, 4 - 5mm
Periodontal treatment, subgingival debridement, re-evaluate at 3 months


  • Deep,≥6 mm
Full periodontal examination, full charting, radiographs, Staging and Grading, possible referral to specialist periodontist
Citation: Adopted from HF Wolf & KH Rateitschak, Color Atlas of Dental Medicine - Periodontology. Thieme: 2005


With these diagnostic records and thorough patient history, you may then stage and grade the patient, BSP-style.1

Grading and Staging Patients Under BSP Periodontitis Diagnosis Criteria

Under the 2018 criteria in dentistry, staging and grading are crucial processes for assessing the severity and aggressiveness of oral cancers. The BSP provides a straightforward approach, ensuring that dentists can effectively determine the extent of the disease and its biological characteristics, facilitating more informed treatment decisions for improved patient outcomes. We can return to the example patient to go through the staging and grading process.


  1. Identify the single worst periodontitis-affected tooth among the periapical views.

  2. Ascertain the amount of radiographic bone loss.

  3. Assign a stage
  • Stage I (early/mild disease): Only "blunting" of the interdental bone crest (<15% RBL).

  • Stage II (moderate): Bone loss to the coronal third of the root.

  • Stage III (severe): Bone loss to the middle third.

  • Stage IV (very severe/advanced): Bone loss to the apical third
Frontal retracted view of example patient
Figure 1: Frontal retracted view of example patient.
Portrait view of patient's smile
Figure 2: Portrait view of patient’s smile.
Left and right buccal view
Figure 3: Left and right buccal view.
Left and right buccal view
Figure 4: Left and right buccal view.
Full mouth set of periapical views
Figure 5: Full mouth set of periapical views.

In our example patient (Figs 1-5), the worst-affected teeth appear to be teeth #9, #19, #26, and #30. The lower right first molar (#30) appears to have bone loss to the apical third of its distal root, a rapid diagnosis of stage IV. We should not use tooth #19 for staging, since this tooth likely has an endo-periodontal lesion, and the extent of radiographic bone loss cannot solely be attributed to the periodontal disease.

Staging, BSP-style, radiographic bone loss at single worst tooth site (Adapted from Dietrich et al, 2019)
Figure 6: Staging, BSP-style, radiographic bone loss at single worst tooth site (Adapted from Dietrich et al, 2019).


Staging of periodontitis

Stage I


Stage II


Stage III


Stage IV

(very severe)

Interproximal bone loss* <15% or <2 mm** Coronal third of root Mid third of root Apical third of root

Describe as:

Localised (up to 30% of teeth),

Generalised (more than 30% of teeth)

Molar/incisor pattern


Staging, BSP-style (Adapted from Dietrich et al, 2019)
Figure 7: Staging, BSP-style (Adapted from Dietrich et al, 2019)).

With regards to extent, this patient may seem like an obvious molar/incisor periodontitis case but, in fact, had numerous pockets throughout the quadrants.


Should a 70-year-old patient present with loss of interdental papillae and radiographic blunting of the interdental crests, there would be little concern. The same loss of attachment in a young child? Great concern! Why? Because we consider the patient’s age in relation to the severity of the disease.

To grade a periodontitis patient:

  1. Calculate a ratio of the patient’s RBL % over their age. In our example patient, there is 90% bone destruction of #30 distal root. The patient is 32 years old; the ratio is 90/32.

  2. Assign a grading:
  • Grade A (slow rate of progression): A ratio of

  • Grade B (moderate rate): Ratio between half and 1.

  • Grade C (rapid rate, high risk): Ratio >


Grading of periodontitis

Grade A


Grade B


Grade C


% bone loss / age <0.5 0.5-1.0 >1.0
Example 25% RBL/60 yrs old   40% RBL/38 yrs old
Grading, BSP-style (Adapted from Dietrich et al, 2019)
Figure 8: Grading, BSP-style (Adapted from Dietrich et al, 2019).

Our case example:

  • 32 yrs old
  • 90% RBL
  • Ratio >1
  • Grade C


In our example, 90% RBL / age 32 = ratio >1; this patient is at high risk and has a disease that has progressed rapidly, and is likely to continue to do so, especially if not adequately treated.

Unlocking Fast and Effective Periodontitis Diagnosis with BSP

There is much more to add, and for a more comprehensive appreciation of the classification, as well as the BSP implementation, the reader is referred to the citations list in this and part 1 to explore these in full. That said, this article shares that for the first time ever, periodontitis patients can be rapidly and effectively diagnosed, as we do dental caries and other everyday conditions. With minimal practice, any dentist can, within seconds of viewing a radiograph, assign a stage and grade to a patient. These diagnoses, in turn, relate to the patient’s disease severity and how complex treatment may be, identifying the possible need for referral and the risk of disease progression if not adequately managed.

Know that critiquing the literature, the original classifications (old and new) are not the focus of this article. The critique merely helps to emphasize the need for dentists to access a classification system that can be easily implemented in everyday practice. It is this author’s opinion that the BSP implementation, while itself not perfect, effectively solves this age-old challenge of diagnosing periodontitis in our patients.

Jonathan Du Toit, BChD, MSc, MChD (OMP), FCD(SA) OMP, PhD, is a periodontist practicing in Cape Town, South Africa, and is a contributor to Spear Digest.


  1. Dietrich, T., Ower, P., Tank, M., West, N. X., Walter, C., Needleman, I., et al. (2019). Periodontal diagnosis in the context of the 2017 classification system of periodontal diseases and conditions - implementation in clinical practice. British Dental Journal, 226 (1), 16-22.
  2. Dowell, P., & Chapple, I. L. (2002). The British Society of Periodontology referral policy and parameters of care. Dental Update, 29 (7), 352-3.
  3. Wolf, H. F., & Rateitschak, K. H. Color Atlas of Dental Medicine Periodontology. New York