Antibiotic prophylaxis

- this image is the first time we went to Singapore for Australia dental council exam, so happy with two angels-

Antibiotic prophylaxis is the administration of antibiotic before a dental procedure to minimize the risk of bacterial infection. It is only given when the risk of infection is high. Infection can occur at :

* a distant site through the haematogenous route, usually the heart ( eg endocarditis )
* an oral surgical site

There is a very small risk infection at a prosthetic joint site through the haematogenous route. Therefore antibiotic prophylaxis is not recommended before dental procedure in patients with prosthetic joints.

If required, antibiotic prophylaxis should be given just before the . The aim is to achieve high plasma and tissue concentration is most likely. Prescribing antibiotics after the procedure is of no prophylactic value.

PREVENTION OF ENDOCARDITIS

Infective endocarditis is relatively uncommon illness with high morbidity and mortality. The incidence in Australia approximately five cases per 100 000 person - years and the in- hospital mortality is 15 to 20 %.

For many years, antibiotic prophylaxis was routinely administered before dental and other procedures to patients with cardiac conditions that carry a high lifetime risk of infective endocarditis. However, endocarditis after dental or other procedures is infrequent, so prophylaxis prevents very few cases. Infective endocarditis is more likely to result from bacteraemia associated with daily activities than from specific dental procedures , so the maintenance of good oral health and hygiene is more important than periprocedural antibiotics. Endocarditis can occur after hospitalisation, especial in older, sicker patients with diabetes or chronic kidney impairment. However, this does not appear to be a sequel to particular procedure but rather to problems such as IV - site infections. This emphasises the nee for infection and control strategies in hospitals.
No randomized controlled trial has been performed to determine the role of antibiotic prophylaxis, and there are no human studies showing that it can prevent endocarditis . Consequently, guidelines rely on expert consensus . Since 2002, many international guidelines have significantly reduced the number of indications for antibiotic prophylaxis for endocarditis. NICE in the UK went even further in 2008 recommended that antibiotic prophylaxis is not requires for any person before dental or other procedures.

Several studies have examined the impact of the changes in guidelines and have not found an increase in the number of cases of endocarditis , including in the UK. However, it appears that the NICE guidelines have not been universeally followed in the UK , so the safety of their recommendations is yet to be proven. Therefore, TG continues to recommend antibiotic prophylaxis in a restricted group of patients until further evidence is available.

Antibiotic prophylaxis is recommended only for patients with a cardiac condition associated with the highest risk of adverse outcomes from endocarditis who are undergoing certain dental procedures or other procedures. This list of cardiac conditions is short ; all of these patients have had significant cardiovascular disease or interventions. Prophylaxis is also recommended for high risk patients with documented rheumatic heart disease. Prophylaxis is not recommended for patients with other form of valvular or structural heart disease, including mitral valve prolapse.

It is thought that Indigenous Australia with rheumatic heart sisease are at high risk of developing infective endocarditis and for adverse outcomes from the disease. However, it has been argued that the higher risk and poorer outcomes are associated with socioeconomic disadvantage rather than ethnicity.
New Zealand guidelines recommend prophylaxis for all patients with rheumatic heart disease , specifically including Maori and Pacific Islander people. It is the consensus view of the Antibiotic Expert Group that antibiotic prophylaxis should be administered to all Indigenous Australians with rheumatic heart disease who are undergoing certain dental procedures or other procedures. Non- Indigenous patients with rheumatic heart disease and who are at sinificant socioeconomic disadvantage should also be considered for antibotic prophylaxis.

In making the decision about whether to administer antibiotic prophylaxis before a procedure in a particular patient, the following risks must be considered.: the risk of giving the antibiotic, the risk of the patient developing endocarditis from procedure, and the risk of potential adverse outcome if the patient does develop endocarditis.

All patients with cardiac abnormalities should be reminded to practice good oral hygiene and have regular dental check ups, with preventive dental and periodontal treatment to ensure optimal oral health .
In particularly, dental examination is recommended twice yearly for patients with a cardiac condition involving endocardium.
Doctors should investigate an unexplaned
fever because it could be a sign of endocarditis, and take samples for blood cultures before administering any oral or IV antibiotics.

NPS Medicine Wise has developed a patient information resource to help practitioners explain the guidelines on prevention of endocarditis

Cardiac condition associated with the highest risk of adverse outcomes from endocarditis

Antibiotic prophylaxis is recommended in patients with following cardiac conditions who are undergoing certain dental procedures or other procedures:
* Prosthetic cardiac valve or prosthetic material used for cardiac valve repair
* Previous infective endocarditis
* Congenital heart disease but only if it involves:
+ Unrepaired cyanotic defects, including palliative shunts and conduits
+ Completely repaired defects with prosthetic material or devices, whether placed by surgery or catheter intervention, during the first 6 months after the procedure ( after which the prosthetic material is likely have been endothelialised)
+ repair defects with residual defects at or adjacent to the site of a prosthetic patch or device ( which inhibit endothelialisation).
* Rheumatic heart disease in high risk patients

Patients who have had a heart transplant may also be at high risk of adverse outcome from endocarditis: consuit the patient's cardiologist for specific recommendations.

Table 8: Dental procedures and their requirement for endocarditis prophylaxis in patients with a cardiac condition listed above

Prophylaxis always required:
* Extraction
* periodontal procedures including surgery, subgingival scaling and root planing
* replanting avulsed teeth
* other surgical procedures ( eg apicoectomy)

Prophylaxis required in some circumstances:
* Consider prophylaxis for the following procedures if multiple procedures are being conducted, the procedure is prolongrd or periodontal disease is prevent:
* Full periodontal probing for patients with periodontitis
* intraligamentary and intraosseous local anaesthetic injection
* supragingival calculus removal / cleaning
* rubberdam placement with clamps ( where there is a risk of damageing gingiva)
* restorative matrix band/ strip placement
* endodontics beyond the apical foramen
* placement of orthodontic bands
* placement of interdental wedge
* subgingival placement of retraction cords, antibiotic fibres or antibiotic strips

Prophylaxis is not required:
* oral examination
* infiltration and block local anaesthetic injection
* restorative dentistry
* supragingival rubber dam clamping and placement of rubber dam
* intracanal endodontic procedures
* removal of sutures
* impression an construction of dentures
* orthodontic bracket placementand adjustment of fixed appliances
* application of gels
* intraoral radiographs
* supragingival plaque removal