1. Medical evaluation of the patients

2. Prior to any dental procedure or administration of any drags , particularly , local anesthetic agents , the dental practitioner should determine whether the patient can tolerate the procedure or the drug safely or not . Specific modification in the treatment are necessary to decrease the risk associated with the procedure or the drugs . This is important , as the local anesthetic agents , like many other drugs , exert actions on many system of the body .

3. local anesthetic agents undergo biotransformation in liver ( amides ) or blood (esters) . Hence , the functional status of these systems should be determined before the administration of the drug . Further , the local anesthetic agents are excreted through kidneys . Hence , status of kidneys should also be evaluated

4. Medical evaluation Detailed medical history
The dental practitioner should get detailed information about the current status of medical history at the first visit and record it as :
1- History of major illness or been under treatment in the past. These questions give you information about patient general health .
2- The drugs the patient is taking presently , and medications taking presently , and medications taken during the past 2 years .
3- Is the patient taking any antiplatelet or anticoagulant medication .
4- The medical status should be updated regularly in the records .

5. History of hospitalization
The patient should be asked if there is any previous hospitalization and its cause also we should ask about how long did the patient stay in the hospital , and even maternity history should be taken in case of female patient .
Fear and anxiety or nervousness
The dental practitioner can determine whether any additional steps as sedation , stress reduction protocol or anxiety reduction protocol are required to aid in achieving pain control .

6. History of allergy to drugs The patient should be asked about having allergy to any drugs as 1- Drugs as penicillin , sulpha group of drugs , aspirin or codein . 2- The incidence of true , documented , and reproducible allergy to local anesthetic agents . 3- Allergy not due the local anesthetic agent itself but due to any constituents of the local anesthetic solution which could be the cause of the allergy and those are : a- Preservative to the vasoconstrictor such as sodium bi – sulfite or Na meta – bisulfite . b- General preservative such as Methylparaben

7. History of excessive bleeding that required special treatment
It is very important to ask the patient if he had any history of excessive bleeding associated with the pervious dental treatment and to prevent this complication from happing .
Patients with the following bleeding disorders are at risk of bleeding :
1- Coagulation disorders .
2- Bleeding disorders .
3- Patients taking antiplatelet or anticoagulant drugs .

8. For these patients in insertion of an injection needle in the deeper soft tissue of the oral cavity which are highly vascular in nature may lead to sever bleeding which could be difficult to manage , in such cases techniques which require deep penetration of the dental needle should be avoided such as inferior dental nerve block , maxillary nerve block , and posterior superior nerve block . the dentist could use other technique for those patients such as supraperiosteal injection and periodontal ligament injection , also dentist should refer those patients to their physician take all the necessary local hemostatic measures .

9. Past dental history If there is a history of past bad experience in the dental office , if any require use of additional procedure such as psycho-sedation ,also the dentist should ask the patient if there is any complication associated with any previous dental treatment as fainting of the patient during giving local anesthesia , sever bleeding associated with any previous dental treatments

10. Major illness 1- Cardiovascular diseases .
2- Cerebrovascular accident as stroke .
3- Renal disease such as chronic renal failure .
4- Endocrine disease as diabetes mellitus and thyroid dysfunction .
5- Respiratory disease as bronchial asthma .
6- Neurological disorders as epilepsy .
7- Patients with liver disease as viral hepatitis .
8- Patients on psychiatric medications .
9- Hematological disorders such as anemia and hemophilia .
10- Pregnancy .
Aids

11. Cardiovascular diseases
The patient might be having any of the following cardiovascular disease which need modification of the treatment strategy :
a- Ischemic heart diseases There are :
Angina pectoris : it is defined as an attack of transient chest pain which is usually relieved by rest or administration of a vasodilator , angina is of two types either stable angina or unstable angina , stress , anxiety and inadequate pain control may precipitate an angina attack during dental treatment so the patient should have a morning appointment , reduce the stress during the procedure and some time even use of plane anesthesia is needed .

12. II. Myocardial infarction : patients with a history of a recent attack (within or <6 months ) have increased risk during dental care or even after the administration of local anesthetic drugs , such patients shouldn`t receive any elective dental care within the first 6 month after the myocardial infarction and after this period dental treatment could be performed with appropriate modification and consultation with his physician .

13. b. Congestive heart failure
Patient with heart failure are less tolerant to stress so anxiety must be dealt with adequately , psycho-sedation is appropriate , also those patients are not comfortable in the supine position because of orthopnea and they are more comfortable in upright position .
c. Hypertension :
It`s a medical condition where blood pressure in the arteries persistently elevated , the blood pressure is expressed by two measurements the systolic and the diastolic and when the blood pressure is above 140mm hg/90mm hg then the patient is known to be hypertensive .

14. Patients with mild to moderate elevation in blood pressure are in acceptable risk for dental care , including use of local anesthesia with vasoconstrictors having higher dilution or avoided , all hypertensive patients should follow compliance , they should make it a point to take morning dose of medication , their blood pressure should be checked at each appointment and be managed on the basis on the most recent reading .

15. d. Congenital heart disease , Rheumatic heart disease Patients who fall in this categories are in risk of developing bacterial endocarditis following any dental treatment especially surgical one so they require prophylactic antibiotic before that dental treatment and there is certain regimen for antibiotic prophylaxis which is advised by the American heart association . e. Artificial heart valve: Patients with prosthetic heart valve antibiotic prophylaxis before any dental care. also those patients are usually taking anti-coagulant drugs which should be stopped or reduced gradually few days before the surgical procedure in consultation with the patients physician .

16. Cerebrovascular accident , stroke
Those patients are at high risk for complications following dental treatment within the first 6 months after the acute attack and after the first 6 months , their condition require modification of the treatment to decrease the risk of the dental treatment . the guidelines are as follows
1- Monitor the blood pressure .
2- Those patients are usually taking anti-coagulant drugs which should be stopped or reduced gradually prior to any dental treatment .
3- Use minimum dose of the local anesthetic agent .

17. Renal disease ( chronic renal failure ) : A small percentage (<10%) of local anesthetic agent is excreted unchanged by the kidney in the urine . the patients with chronic renal failure achieve high levels of local anesthetic agent in the blood , thereby increasing the risk local anesthetic overdose .

18. Endocrine disease 1- Diabetes mellitus
Those patients are mostly susceptible to delay healing and infection after dental treatment because of high level of sugar in the blood so uncontrolled patients should be referred to their physician to control their blood sugar level before any dental treatment also the surgical procedure is carried out under antibiotic cover .

19. 2- Thyroid dysfunctions
The signs and symptoms of hyperthyroidism include sensitivity to heat , easy sweating , tachycardia , palpitation weight loss , increased body temperature , tremor of the extremities , increased nerves ness , patients with hyperthyroidism are sensitive to catechlamines and may demonstrate an exaggerated response to vasopressor include in local anesthetic solution so for those patients plane anesthesia (local anesthetic solution without vasoconstrictor) should be used .

20. Respiratory diseases
Patients with respiratory disease such as bronchial asthma , are treated with stress reduction protocol . They should use the inhaler on the day of surgery , and also keep it with them during the dental or surgical procedure . The medication for bronchodilatation should be kept handy , incase of an emergency . if the patient is using corticosteroids its necessary to consult his physician double his dose of steroid .

21. Neurological disorder
Epilepsy
For epileptic patient the main problem which may happened on the dental chair is the epilepsy fit , the epilepsy fit may occur due to several causes as stress , hypoglycemia , hyperventilation . Stress may provoke seizures even in patients with well – controlled epilepsy so stress reduction protocol should be employed to minimize the risk of seizures development during treatment and there are other precautions should be taken by the dentist during the dental treatment .

22. Patients with liver disease
Patients with liver disease especially with a history of viral hepatitis must be managed as though they are potentially infectious to the dentist and to other patients , in a dental office infection can be expedited through several routs including direct contact with blood , oral fluids , or other secretions , or by indirect contact with contaminated instruments and operatory equipment`s . and because there is an increased risk of infection via the blood or the saliva to the dentist or to other patients , thorough evaluation of the disease should be carried out to assess the degree of the risk to both the practitioner and to the patient before any dental treatment . also it is recommended that the dental professionals should receive immunization against hepatitis and should use individual protective equipment`s such as gloves , head cap , masks , etc. and the instruments used should be sterile separately . .

23. In significant liver dysfunction the half – life of amide local anesthetic agent may be significantly prolonged thereby increasing the risk of overdose . the local anesthetic agent are detoxified in the liver , and hence , should only be used if approved by the treating physician

24. Patients with psychiatric ailments and on medications
Patients under psychiatric care , for neurosis , psychosis , and depression usually take psychiatric drugs to alter the behavior patterns , there are 2 types of these drugs which are
1- TC antidepressants .
2- MAO inhibitors .
These drugs pose a minimal risk to the administration of local anesthetic agent with vasoconstrictor so plane local anesthesia should be used for those patients .

25. Hematological disorders
Anemia
There are various forms of anemia which are as follows
1- Methemoglobinemia
2- Iron deficiency anemia
3- Sickle cell anemia
Methemoglobinemia , which can be congenital , or acquired is a relative
Contraindication to the use of Prilocaine , other forms of anemia do not pose any problem for the administration of local anesthetic solution with or without vasoconstrictors .

26. Deficiencies such as hemophilia , Leukemia , Thrombolytic purpura , and thalassemia
In all these disorders , the deficiencies are corrected with the help of the hematologist and with the necessary precautions of local hemostatic measures , surgical intervention can be undertaken . local anesthesia by block technique , lingual infiltration injection , or injection into floor of the mouth must not used in absence of factor VIII replacement because of the risk of hemorrhage hazarding the air way and being life threatening , infiltrations as intraligamentary , intraosseous , or intra pulpal injection are still safer .

27. Pregnancy
It is relative contraindication for elective dental care , especially in the first and the third trimesters , consultation with the patients physician is necessary prior to oral surgical procedures involving use of local anesthesia , particularly if there is history of any problems with the previous pregnancies or if the patient is a primigravida .
local anesthetic agents and vasoconstrictors are not teratogens and may be administered to pregnant patients during any trimester . however it is important to be conservative in administering any drug to a pregnant patient . local anesthetic agents containing felypressin such as Citanest fort (Prilocaine and Octapressin ) has got oxytocic properties but lidocaine can be safely used .

28. AIDS
In a patient who is known case of AIDS conservative dental treatment could be done with several precautions as using face mask , head cap , and double gloves , today special kit is available for single patient use . The instruments used are sterilized by chemical sterilization by immersing in 1% sodium hypochlorite for 10 hours followed double autoclaving .

29. Thank you for listening