MFDS Part 1 - Membership of Faculty of Dental Surgery Periodontology and Oral Hygiene Questions and Answers — Questions and Answers
Question 1: A 52-year-old patient presents for a routine examination. Clinical assessment reveals probing depths up to 7mm and radiographic bone loss extending to the middle third of the root on the most severely affected teeth. Four teeth have been lost due to periodontitis. According to the 2017 Classification of Periodontal Diseases, as implemented by the British Society of Periodontology (BSP), what is the correct stage for this patient?
- Stage I
- Stage II
- Stage III
- Stage IV (Correct answer)
Correct answer: Stage IV
According to the 2017 classification system, Stage IV periodontitis is assigned when there is severe periodontal destruction (as seen in Stage III) plus additional complexities such as the loss of 5 or more teeth due to periodontitis, or the need for complex rehabilitation. While bone loss to the middle third and deep pockets are characteristic of Stage III, the loss of 4 teeth due to periodontitis is a complexity factor that, when combined with the severe destruction, can push the diagnosis to Stage IV, although the primary determinant for Stage IV is 5 or more teeth lost. However, given the options, Stage IV is the most appropriate classification due to the tooth loss and severity, distinguishing it from Stage III which is severe periodontitis without the need for complex rehabilitation or significant tooth loss (≤ 4 teeth lost).
Question 2: A 45-year-old new patient is diagnosed with generalised Stage III Grade B periodontitis. In line with the British Society of Periodontology (BSP) S3 Level Clinical Practice Guideline, what is the mandatory first step of active periodontal therapy?
- Referral for surgical periodontal therapy.
- A course of systemic antibiotics combined with full mouth disinfection.
- Supragingival professional mechanical plaque removal (PMPR), detailed oral hygiene instruction, and risk factor control. (Correct answer)
- Immediate subgingival instrumentation (root surface debridement) under local anaesthesia.
Correct answer: Supragingival professional mechanical plaque removal (PMPR), detailed oral hygiene instruction, and risk factor control.
The BSP S3 guideline outlines a stepwise approach. Step 1 is foundational and must be completed for all periodontitis patients. It focuses on building patient motivation, providing personalised oral hygiene instruction, controlling risk factors (like smoking or poor glycaemic control), and performing supragingival professional mechanical plaque removal. Subgingival instrumentation (Step 2) is only undertaken after the patient has demonstrated engagement and improvement in plaque control following Step 1.
Question 3: What is the primary therapeutic objective of non-surgical root surface debridement (RSD) in the management of periodontitis?
- To remove the outer layer of contaminated cementum.
- To disrupt the subgingival biofilm and remove calculus deposits. (Correct answer)
- To create a glass-smooth root surface to prevent plaque re-adhesion.
- To eliminate all bacteria from the periodontal pocket.
Correct answer: To disrupt the subgingival biofilm and remove calculus deposits.
The modern understanding of non-surgical periodontal therapy emphasises that the main goal is to disrupt the pathogenic subgingival biofilm and remove plaque-retentive factors like calculus. This reduces the inflammatory load and allows for periodontal healing. The older concept of aggressive 'root planing' to remove all cementum and create a perfectly smooth surface is no longer advocated, as it can be unnecessarily destructive. Sterilisation of the pocket is not a realistic or necessary goal.
Question 4: A 60-year-old patient with poorly controlled Type 2 diabetes (HbA1c of 9.5% or 80 mmol/mol) presents with severe, generalised periodontitis. What is the primary mechanism by which their systemic condition exacerbates their periodontal disease?
- It directly causes xerostomia, leading to increased plaque accumulation.
- It leads to an altered, hyper-inflammatory host response to periodontal pathogens. (Correct answer)
- It reduces the mineral content of alveolar bone, making it more susceptible to resorption.
- It causes direct necrosis of the periodontal ligament fibres.
Correct answer: It leads to an altered, hyper-inflammatory host response to periodontal pathogens.
The link between diabetes and periodontitis is bidirectional. Poorly controlled diabetes leads to an exaggerated or hyper-inflammatory response to the bacterial challenge in the periodontal tissues. This is mediated by factors such as Advanced Glycation End-products (AGEs), which result in increased production of inflammatory mediators and enhanced tissue destruction. While other factors may play a minor role, the altered host inflammatory response is considered the principal mechanism.
Question 5: A patient undergoing treatment for Stage III periodontitis has generalised gingival recession, resulting in large, open interdental spaces. According to UK guidance, such as 'Delivering Better Oral Health', what is the most effective and recommended tool for daily interdental plaque removal in these areas?
- Dental floss
- Interdental brushes (Correct answer)
- Rubber-tipped stimulators
- An oral irrigator
Correct answer: Interdental brushes
For patients with periodontitis who have open interdental spaces, interdental brushes are consistently shown to be more effective at removing plaque than dental floss. UK guidelines, including those from the BSP and Public Health England's 'Delivering Better Oral Health', recommend interdental brushes as the first choice for these patients, with the size of the brush being matched to the space.
Question 6: A patient with a dental implant complains of redness and swelling of the surrounding mucosa. Probing reveals bleeding on gentle probing and a pocket depth of 5mm. What single additional finding is essential to differentiate a diagnosis of peri-implantitis from peri-implant mucositis according to the 2017 classification?
- The presence of suppuration from the peri-implant sulcus.
- Patient-reported discomfort around the implant.
- Radiographic evidence of bone loss beyond initial remodelling. (Correct answer)
- A probing depth greater than 6mm.
Correct answer: Radiographic evidence of bone loss beyond initial remodelling.
According to the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions, the key feature that distinguishes peri-implantitis from peri-implant mucositis is the presence of progressive radiographic bone loss beyond the initial bone remodelling that occurs after implant placement. Peri-implant mucositis is characterised by inflammation (e.g., bleeding on probing) without this progressive bone loss.
MFDS Part 1 - Membership of Faculty of Dental Surgery Periodontology and Oral Hygiene Questions and Answers
A 52-year-old patient presents for a routine examination.
Clinical assessment reveals probing depths up to 7mm and radiographic bone loss extending to the middle third of the root on the most severely affected teeth.
Four teeth have been lost due to periodontitis.
According to the 2017 Classification of Periodontal Diseases, as implemented by the British Society of Periodontology (BSP), what is the correct stage for this patient?