8: Case study

The case study below serves as an example of how to apply the content from previous chapters to a patient. This will only cover some conditions. General medicine relevant to Dentistry will be covered in more detail in year 3.

Please note: If you have a patient with a condition you are unfamiliar with, further reading is required.

Case introduction

Alex Morris is a 60-year old man. He works as an accountant in the city.

• Chief complaint and history of presenting illness:  He is attending this clinic for a general check-up and is concerned about the redness and bleeding around his gums. He also noted that food often gets stuck in between his teeth and he feels his back teeth are becoming loose.
• Medical history:
  • He has an allergy to penicillin.
  • He has a history of intravenous drug use from over 30 years ago and an unknown heart condition that resulted in hospitalisation.
  • He also has diabetes mellitus type 2 and routinely sees a medical practitioner for management;  controlled with diet, exercise and Metformin.
• Social and dental history:
  • Smoker for 40 years, smokes 5-10 cigarettes per day.
  • First visit to this practice. Last dental check up about 4 years ago.

The first video Dentist Checking Notes (YouTube, 1m2s) illustrates dental practitioner reviewing available clinical information and thinks of further questions/ avenues to follow.

Initial consult and medical history

Main points

• Conditions: Diabetes, Infective Endocarditis, Allergy to penicillin
• Medications and relevant points: Antibiotics: Guidelines for prophylaxis, Alternatives to penicillin, Metformin

Watch Patient interview including medical history taking (YouTube, 3m26s) which illustrates dental practitioner bringing the patient in and inquiring as to patient’s reason for visit and medical history details.

Note: patient is wearing mask while in waiting room, as per COVID-19 mandate in Australia in 2022.

What questions should the clinician ask?

Acquire the medical information with targeted questions for smoking, diabetes and infective endocarditis

Diabetes: “I have diabetes.” OR “I take metformin.” 

Relevance: Diabetes and periodontitis have a strong bi-directional association.

• What type of Diabetes do you have? (Determine type: Type 1: Insulin dependent, relies on insulin therapy or Type 2: Non-insulin dependent, relies on diet and medications. Might include oral glucophage or insulin injections) If on insulin: blood sugar could drop too low during treatment, especially if taken without food. Hypoglycemic emergency.
• What was your most recent blood glucose reading? (To determine whether diabetes is controlled.)
• Normal: Fasting plasma glucose 3.5 to 7 mM/L;  2-hour plasma glucose <11 mM/L
• “Are you seeing a medical practitioner for your diabetes?” –  to ensure appropriate medical attention is given.

Smoking: “I smoke.”

Relevance: Smoking adversely affects healing and treatment outcomes. (Treatment outcomes from periodontal therapy are less favourable with smoking.)

• “How much do you smoke a day? How many years have you smoked?” (Frequency indicates severity)
• Use motivational interviewing techniques to encourage him not to smoke.

Hospitalisation and previous Infective Endocarditis

“I had a heart infection 30 years ago. I went to hospital for it. I can’t remember exactly what it was. I remember taking antibiotics for weeks for it. I am embarrassed they said it was probably due to my drug habit.” 

Relevance: The patient may have previous infective endocarditis. If confirmed, then they may require antibiotic prophylaxis for invasive treatments, e.g. deep subgingival debridement. Need to contact primary care team to confirm.

• Infective Endocarditis is a relatively uncommon illness with high morbidity and mortality. The incidence in Australia is approximately five cases per 100,000, and the in-hospital mortality is 15 to 20%
  • • For many years, antibiotic prophylaxis was routinely given before dental and other procedures to patients with cardiac conditions that have a high lifetime risk of infective endocarditis. However, endocarditis after these procedures is rare, so prophylaxis prevents very few cases.
    • Endocarditis-related bacteraemia is more likely to result from daily oral hygiene activities than from specific procedures and is strongly associated with poor oral hygiene and gingival disease. Therefore, the maintenance of good oral health and hygiene is more important than the use of antibiotic prophylaxis. Oral hygiene is important for the general population but particularly for patients with a cardiac condition listed in the Electronic Therapeutic Guidelines (UQ staff and students).

• Protocol summary: 

  • Ensure you only prescribe if they meet both the cardiac condition and the dental procedure as above.
  • Minimise number of dental appointments if antibiotic prophylaxis is needed due to risk of infective endocarditis.
  • The prescription is a single dose of  Amoxycillin 2g orally 60 minutes before procedure. If patient is allergic and amoxycillin is contraindicated, we can prescribe a singe dose of Clindamycin 600mg orally 60 minutes before procedure.

Rationale for Antibiotic prophylaxis

In patients with specific cardiac conditions, there is a risk of infective endocarditis occurring after dental procedures involving manipulation of the gingival or periapical tissue OR perforation of the oral mucosa. This is prevented by prophylactic antibiotics i.e a one-off dose of oral OR intravenous antibiotics taken by the patient 30-60 mins prior to the dental procedure.

Medical conditions that require antibiotic prophylaxis (2023) as per eTG

1. Prosthetic cardiac valve, including transcatheter-implanted prosthesis or homograft
2. Prosthetic material used for cardiac valve repair, such as annuloplasty rings and chords
3. Previous infective endocarditis
4. Congenital heart disease but only if it involves:
   • unrepaired cyanotic defects, including palliative shunts and conduits
   • repaired defects with residual defects at or adjacent to the site of a prosthetic patch or device (which inhibit endothelialisation)
   • rheumatic heart disease.

Indicated only for dental procedures such as

• Manipulation of the gingival or periapical tissue OR perforation of the oral mucosa
  • • • Extraction
      • Implant placement
      • Biopsy
      • Removal of soft tissue or bone
      • Subgingival scaling and root planning
      • Replanting avulsed teeth

Regimens

• Not allergic to pencillin: 2 gm amoxicilin orally, (child: 50mg/kg upto 2 gm)  60 mins before procedure
• Patient has stated “I have an allergy to pencillin”  so following should be followed: 
  • Patients with delayed non severe hypersensitivity to pencillins: cefalexin 2 gm orally (child 50mg/kg upto 2 gm) 60 mins before procedure.
  • Patients with immediate (severe or non-severe) or delayed severe hypersensitivity to penicillins, use: clindamycin 600 mg orally (child 20 mg/kg upto 600 mg)  60-120 mins before the procedure. 

Communicating with primary health care team

Watch Calling the GP (YouTube, 2m01s) illustrates the dental practitioner calling the patient’s doctor to confirm reason for hospitalisation and explaining the need for antibiotic cover.

Prescription for antibiotic prophylaxis and completing initial consult

Watch Need for antibiotic cover (YouTube, 1m 32s). It illustrates the dental practitioner communicating with the patient around conversation with GP and explaining the need for antibiotic cover as the patient has an eligible condition and there will be invasive dental treatment. Dentist provides a prescription and has asked the patient to come back the same afternoon, so both charting and initial treatment can be completed under antibiotic prophyllaxis.

Watch Dentist completing charting and treatment under antibiotic cover (YouTube, 2m59s), illustrating a patient being treated after antibiotic was taken, with initial appointment rescheduled to same afternoon.