Dr. Reham Lotfy AggourLecturer of oral Medicine,

Periodontology, Oral diagnosis and Radiology

Significant lab tests in dentistry

HEMATOLOGIC TESTS

Includes:CBC: Complete Blood Count with

Platelet and WBC differential.ESR: Erythrocyte Sedimentation

Rate.Laboratory tests assessing

haemostasis.

Platelets

• Normal platelet count: 150.000: 400.000 cells/mm3

• Primary hemostasis needs adequate platelet count &function

Thrombocytopenia

For periodontal or maxillofacial surgery platelet count should be above 75.000/mm3

For major surgeries with general anesthesia

platelet count should be above 100.000/mm3

Spontaneous bleeding occurs when the platelet count is below 20.000/mm3

Elements of Hemostasis

1. Adequate blood vessel response.

2. Adequate platelet count.

3. Adequate platelet function: Bleeding time.

4. Adequate level of Von Willebrandʼs factor.

5. Adequate levels of clotting factors : PT/INR, PTT.

Clotting Factor TestsPT (Prothrombin Time)

• Tests extrinsic and common pathways.

• Normal (11-15 sec)• Coumarin therapy PT at 1.5

to 2.5 time• International normalized

ratio INR=1• Surgery can be done if INR <

3

Partial thromboplastin time (PTT)

• Tests intrinsic pathway.• Normal (25-35sec).• Affected by heparin

anticoagulant

Case 1A 59 years old man

presents to the dental office for extraction of one of his lower teeth. History reveals that he had 2 venous thromebolic events and is on warfarin therapy (oral anticoagulant):

• Which of the following investigations should be performed to evaluate the risk of bleeding?

1) Blood glucose level2) ESR3) Complete blood count4) Prothrombin time

Case 2

A 18-year old female complains about gingival bleeding and epistaxis in addition to the above lesions.

1) What are the lab investigations that should be performed?

• A 26-year old man attend the dental office for extraction of one of his teeth. History revealed spontaneous gingival bleeding .

Investigation shows:Hb 13.5 g/dlPlatelets 12.000White blood cells 6.000/mm3

PT (13 sec)PTT (26 sec)

• What is the cause of bleeding? Explain.

• A 28 year old lady was diagnosed with acute leukemia. She required extraction of her lower third molar. Her platelet count was found to be 11.000/mm₃

• What is the best action? Why?

• A 15-year old girl presented to her dentist with a complain of spontaneous bleeding and palatal bruising. Investigation shows:

Hb 14.5 g/dlPlatelets 17.000 /mm3

White blood cells 7.000/mm3

PT (11 sec)PTT (23 sec)

• What is the cause of bleeding? Explain.

• A 37-years old female who has a prosthetic valve came to the dental office complaining of left submandibular swelling. A history of dental pain in the lower left quadrant was reported. On examination a tender left unilateral swelling, limited mouth opening and partially impacted lower left wisdom were observed. The dentist decided that this wisdom is indicated for surgical extraction.

• Mention the needed laboratory tests and its normal values?

• What is the best treatment approach based on the result of the laboratory tests?

Laboratory Diagnostic Criteria for Diabetes

Diagnosis is by any of the following three methods and must be confirmed on a subsequent day by any one of the same three methods.

• 1. Presence of diabetes symptoms plus casual (nonfasting) plasma glucose ≥ 200 mg/dL (casual glucose may be drawn at any time of day without regard to time since last meal)

• 2. Fasting plasma glucose ≥ 126 mg/dL (fasting is defined as no caloric intake for at least 8 hours)

• 3. Two-hour postprandial glucose† ≥ 200 mg/dL during an oral glucose tolerance test using a glucose load containing the equivalent of 75 g of anhydrous glucose dissolved in water

Uncontrolled DM : Management

Case 2A 55-diabetic male

complaining of burning sensation in his tongue. On examination a diagnosis of pseudomembranous candidiasis was confirmed . His last random blood glucose level was 350mg/dl .

1) What is the normal value of random blood glucose level?

2) What is the appropriate treatment?

AIDS Definition

• An individual is diagnosed with AIDS if

signs or symptoms from CDC defined

Clinical Category C are present.

• CD4 cells count is bellow 200 cells.

Centers for Disease Control and Prevention classification .

CD4+ T Cells/mm3 orCD4+ Percentage

Clinical Categories

≥ 500 or ≥ 29% A1 B1 C1*

200–499 or 14–28% A2 B2 C2*

< 200 or < 14% A3* B3* C3*

A: Asymptomatic Acute HIV or PGLB: Symptomatic, no A or C ConditionsC: AIDS-Indicator Conditions* Expanded acquired immunodeficiency syndrome (AIDS) surveillance case definition.

Case 3

32 parentral drug user male came to the dental office with a complain of mild roughness and irritation related to both lateral surfaces of the tongue. He also reported a history of frequent attacks of respiratory tract and skin infections during the last 3 months. The dentist diagnosed the lesion as hairy leukoplakia1. What condition is important to

exclude?2. What lab. Investigation that

should be done?

Liver function tests

• Tests for hepatic function

• Tests for hepatobillary disease

• Tests of hepatocellular damage

Tests for hepatic function

• Serum albumin (3.5-5.5 mg/dl)Serum half life of albumin is 14-20 days, and serum levels fall

with prolonged liver dysfunction or acute hepatic failure. Malnutrition and renal or gastrointestinal losses needs consideration in cases of hypoalbuminemia, especially if prothrombin time is normal.

• Prothrompin time (10.5-13 sec) The prothrompin time responds rapidly to altered hepatic

function so it is useful as a daily marker of hepatic function. However, coexistent vit K def. Must be excluded.

Tests for hepatobillary disease• Serum alkaline phosphatase (30-120U/L)

Increrased also in

bone destruction/remodeling

bile duct obstruction

infiltrative liver disease (neoplasms, granulomas)

• Serum bilirubin (0.3-1.0 mg/dl)

Increrased also in

haemolysis in addition to billary obstruction

liver disease.

Tests of hepatocellular damage

• Aspartate aminotransferase (AST)(10-40 U/L): ↑ in

• hepatocellular necrosis

• cardiac or skeletal muscle necrosis.

• Alanine aminotransferase (9-60 U/L): ALT is more

specific for liver cell damage

Hepatitis B virus (HBV)

• HBV surface antigen (HBsAg) +ve in most cases of acute or chronic infection.

• HBV e antigen (HBeAg) Indicates presence of viral replication and high infectivity.

• HBV-DNA Its levels reflect degree of viral replication and predict response to therapy.

• Anti-HBe Reflection of low infectivity

• Anti HBc (IgM or IgG) +ve in all cases of acute or chronic infection.. IgM anti HBc reflects acute infection. Not protective.

• Anti-HBs+ve in late convalescence in most acute cases. Confers immunity.

Hepatitis C virus (HCV)

• Anti-HCV +ve 6-8 wk after exposure, not protective. Persistent in acute, chronic or post infection.

• HCV-RNA Reflects ongoing infection. Levels inversely linked to ttt response.

• A 25-year old man presented to his dentist for oral hygiene prophylaxis. During examination, the dentist observed yellowish discoloration of his sclera, skin and oral mucosa. He asked for investigation which shows:

Hb 14.5 g/dlReticulocyte 0.68% (NR 0.5-2.4%)Platelets 266.000Bilirubin 45 mg/dl (NR 0.3-1.0 mg/dl)AST 1 36 IU/L (NR 10-40 U/L) ALT 240 IU/L (NR 9-60U/L)

• What is the possible cause of the yellow discoloration? Explain.

• A 56-year old man presented to his dentist. During examination, he observed yellowish discoloration of his sclera, skin and oral mucosa. He asked for investigation which shows:

Hb 6.5 g/dlReticulocyte 6.2% (NR 0.5-2.4%)Platelets 166.000Bilirubin 4 mg/dlAST 20 IU/L (NR 10-40 U/L) ALT 30 IU/L (NR 9-60U/L)

• What is the cause of yellowish discoloration? Explain.

• A 66-year old lady presented to his dentist for extraction of one of her upper molars. After extraction, perfuse immediate bleeding occurred. History revealed chronic fatigue and nasal bleeding.

• Investigation shows: Hb 8.5 g/dlMCV 68 fl (No. 80-69)Platelets 12.000 /mm3

White blood cells 6.000/mm3

PT (11 sec)PTT (23 sec)

• What is the cause of bleeding? Explain.

A 55 years old man attended dental clinic complaining of several bruises related to his tongue and palate over the past week without any precipitating trauma . history revealed deep venous thrombosis 2 months ago.

1. What laboratory tests that should be done ?

BONE METABOLISM

• Calcium (9.0-10.5 mg%).• Phosphorous( 3.0- 4.5 mg%).. • Alkaline phosphatase (25 - 115 Units/L).

Hypercalccemia:• Hyperparathyroidism. • Multiple myeloma.• Paget’s disease. • Osteoporosis .• Cancer

Hypocalcemia:• Hypoparathyroidism, • Vit. D deficicency, • Preganancy, • Diuretics

A 65 years old woman admitted to the hospital following a mandibular fracture that resulted from a sudden fall from her bed. history revealed difficulty in climbing up stairs in addition to chronic fatigue. The patient reported living in a residential house. A slight lordosis have been detected

• Serum calcium: 7.5 mg/dl

• Serum phosphate: 2mg/dl

• Alkaline phosphatase enzyme: 233 IU/L

1. What is your D.D?