CONTENTS 1. INTRODUCTION 2. PLASMA 3. ERYTHOCYTES 4. WHITE BLOOD CELLS 5. PLATELETS 6. HEMOSTASIS AND BLOOD COAGULATION 7. CLINICAL CONSIDERATION OF BLOOD IN CONSERVATIVE DENTISTRY AND ENDODONTICS
INTRODUCTION Blood is a fluid connective tissue present in the circulatory system . It is red in color due to the presence of hemoglobin The normal blood volume in adults is around 5L Blood is made up of – FLUID COMPONENT – Plasma (constitutes 55% of blood) FORMED ELEMENTS- ( constitutes 45% of blood) - Erythrocytes [RBCs] -Leukocytes [ WBCs] - Thrombocytes [ Platelets] Dr. A K Jain Human physiology for BDS fifth edition
PLASMA It’s a fluid portion of blood Normal volume is 3500mL Mainly composed of - water (91%) - other substances are : Inorganic substances like Na + ,K + , Ca++ ions , iron , copper Organic substances like proteins , lipids , glucose, urea , creatinine Serum is plasma without clotting factors Plasma proteins : are the proteins present in plasma Important plasma proteins are – Albumin , Globulin , Fibrinogen and Prothrombin
FUNCTIONS OF PLASMA PROTEINS- Maintenance of colloidal osmotic pressure Maintenance of viscosity of blood Buffering action Protein reserve Immunity Blood clotting Transport Dr. A K Jain Human physiology for BDS fifth edition
ERYTHROCYTES They are the most abundant cells present in blood. Normal life span of an RBC is 120 days. They lack nucleus , mitochondria or ribosomes and hence mature RBCs cannot divide . They contain hemoglobin Normal erythrocyte count – Males- 5- 5.5 million cells/mm cube Females- 4.5 – 5 million cells/mm cube Infants – 6- 7 million cells /mm cube BICONCAVE SHAPE
Functions: The functions of RBCs are mainly due to the presence of hemoglobin. They include: Transport of oxygen from lungs to tissues Transport of carbon dioxide from tissues to lungs, and Regulation of acid-base balance ERYTHROPOIESIS : It is the process of formation of RBCs It starts in the 3 rd week of IUL in the mesoderm of the yolk sac From the 3 rd month of IUL, erythropoiesis takes place in the liver and spleen After 5 th month of IUL the fetal bone marrow starts producing RBCs By birth, the bone marrow becomes the only place of erythrocytes production Dr. A K Jain Human physiology for BDS fifth edition
STAGES OF ERYTHROPOIESIS: The various stages between stem cell and matured red blood cell are as follows: 1.Proerythroblast Early normoblast Intermediate normoblast 4. Late normoblast 5. Reticulocyte and 6.Matured erythrocyte. Dr. A K Jain Human physiology for BDS fifth edition
CELL DIAMETER NUCLEUS CYTOPLASM 15-20 μ m Big & strongly Very scanty & basophilic basophilic No Hb. 11-16 μ m Smaller Scanty & basophilic. No Hb. 10-12 μ m Smaller & Hb starts to appear, Denser cytoplasm polychromatic 8-10 μ m Ink spot Plentiful, eosinophilic. nucleus increase in Hb. 8-10 μ m Absent Some RNA still present. 7.5 μ m Absent Hb++.
CHANGES DURING ERYTHROPOIESIS: During this process four important changes are noticed. 1. Reduction in size of the cell (from the diameter of 25 m to 7.2 m) Disappearance of nucleoli and nucleus 3. Appearance of hemoglobin and Change in the staining properties of the cytoplasm Dr. A K Jain Human physiology for BDS fifth edition
FACTORS INFLUENCING ERYTHROPOIESIS: 1.ERYTHROPOIETIN : Glycoprotein hormone that stimulates Erythropoiesis . It increases RBC production , enhances synthesis of Hb , hastens maturation of RBC It is mainly formed in kidney and partly by liver 2. ANDROGENS: They stimulate erythropoiesis . Therefore men have higher RBC count compared to women 3. ESTROGENS: They have inhibitory effect on erythropoiesis by suppression of erythropoietin production Dr. A K Jain Human physiology for BDS fifth edition
4 . HORMONES: Throxine , Cortisol and growth hormone are necessary for RBC production . Interleukin 1, 5 and 3 , granulocyte-macrophage colony stimulating factor (GM-CSF) and BPA all act as local hormones and helps in conversion of stem cells to progenitor cells . 5. DIETARY FACTORS: Iron is necessary for Hb synthesis VitB12 and Folic acid necessary for maturation of RBC Vit B6 , Vit C , Copper, and Cobalt act as cofactors 6. INTRINSIC FACTORS Helps in the absorption of Vitamin B12 Dr. A K Jain Human physiology for BDS fifth edition
FATE OF RBC: Lifespan of RBC is 120 days The destruction occurs mostly in the capillaries of spleen - graveyard of red blood cells The old and fragile RBC is phagocytosed by reticuloendothelial system In the reticuloendothelial cells , they are broken down and Hb is released Subsequently, Hb is broken down into heme and globin Globin is added to the amino acid pool Iron liberated from heme is used again for the synthesis of new Hb The remaining portion of heme is called biliverdin . It is reduced to bilirubin in the liver and secreted through bile
HEMOGLOBIN: Hemoglobin is a conjugate protein present in the RBC It is a globular molecule made up of 4 subunits. Each subunit contains a heme moiety conjugated to a polypeptide 4 polypeptides form the globin portion of Hb molecule There are 2 pairs of polypeptides in each Hb molecule . In a normal adult Hb ( HbA ), two types of polypeptide chains are alpha chains and beta chains. Therefore HbA is alpha2 beta2 Human fetus has HbF . It has alpha2 and gamma 2 polypeptide chains Fetal hemoglobin is replaced by adult Hb soon after birth. Oxygen binding capacity of fetal Hb is greater than adult Hb . This helps in the movement of maternal to fetal circulation
NORMAL VALUE: MALES= 14-18g/ dL FEMALES= 12-16g/ dL INFANTS= UPTO 20g/Dl It is required for transport of oxygen (ii) transport of carbon dioxide and (iii)it also behaves as a blood buffer . Derivatives of haemoglobin- Oxyhaemoglobin , Carboxyhaemoglobin , Carbaminohaemoglobin Methaemoglobin or ferrihaemoglobin , Deoxyhemoglobin , glycohemoglobin D. Venkatesh Basics of medical physiology third edition
BLOOD GROUP Based on the presence or absence of A and B antigens on the red cell membrane individually or in group ,There are four blood groups.
APPLIED PHYSIOLOGY: ANEMIA: Decrease in RBC count, hemoglobin and/or haematocrit values resulting in lower ability for the blood to carry oxygen to body tissues. If Hb values- in men- <13.5gm/ dL and in women-<12gm/ dL , then they are anemic Depending on the cause of anemia, they are classified Anemia due to decreased RBC formation Anemia due to increased RBC destruction Anemia due to blood loss ANEMIA DUE TO DECREASED RBC FORMATION Iron deficiency anemia: Vitamin B12 and folic acid deficiency Pernicious anemia Aplastic anemia
ANEMIA DUE TO INCREASED RBC DESTRUCTION : Thalassemia Sickle cell anemia Hereditary spherocytosis Glucose-6-phosphate dehydrogenase deficiency ANEMIA DUE TO BLOOD LOSS Acute blood loss Chronic blood loss MORPHOLOGICAL CLASSIFICATION Microcytic hypochromic anemia Normocytic normochromic anemia Macrocytic anemia
PATHOPHYSIOLOGY- Decrease in RBCs, Hb levels Diminished oxygen carrying capacity Hypoxia and hypoxia induced effects on organ function Signs and symptoms of anemia CLINICAL MANIFESTATION : Seen only in moderate and severe anemia Patients have : Pallor, Dyspnea , Palpitations, and heart murmurs Headache, vertigo , restlessness and muscle weakness
ORAL MANIFESTATIONS: In Iron deficiency anemia – the mucous membrane of oral cavity and esophagus are atrophic and show loss of keratinization . A smooth red painful tongue with atrophy of filiform and fungiform papillae is seen In Pernicious anemia – There is gradual atrophy of tongue resulting in a bald tongue which is often referred to as Hunter’s glossitis or Moeller’s glossitis In sickle cell anemia – includes osteoporosis and loss of trabeculation of the jawbones with the appearance of large irregular spaces and morphological alterations in nuclei of oral epithelial cells In aplastic anemia – Spontaneous gingival hemorrhages, lack of resistance to infection , ulcerative lesions of oral mucosa and pharynx.
POLYCYTHEMIA A condition where RBC count is increased above 8 million cells/ mm3 There are two types of polycythemia : Polycythemia Vera It is produced due to genetic abnormality. The blast cells start producing too many cells. This increases the hematocrit value , total blood volume and viscosity of blood . 2. Secondary polycythemia Physiological polycythemia occurs at high altitude due to hypoxia Pathological polycythemia occurs in pulmonary disease, hydronephrosis of kidney and tumors of the liver and kidneys Dr. A K Jain Human physiology for BDS fifth edition
HEMOGLOBINOPATHIES: The defects are due to the abnormalities in the polypeptide chain. The abnormal hemoglobins produced are HbS , HbC , and HbE HbS – In this type of hemoglobin , valine replaces glutamic acid at the sixth position in the beta chain . When HbS is exposed to hypoxia , it becomes insoluble leading to a change in the shape of RBC The homozygous individuals suffer from this condition leading to sickle cell anemia . They are less flexible than normal RBCs. This leads to blocking of capillaries The heterozygous individuals have sickle cell trait
THALASSEMIA In this condition, alpha and beta chains of globin are normal, but they are produced in less number or absent. The decrease in alpha chain synthesis is called alpha thalassemia Alpha thalassemia is of two types- 1. alpha thalassemia major 2. alpha thalassemia minor Beta thalassemia is caused due to reduced synthesis of beta chains It is of two types 1. Beta thalassemia major 2. Beta thalassemia minor In beta thalassemia major , the patients suffer from anemia due to rapid destruction of RBC’s They need frequent blood transfusion There is increased bone marrow activity , leading to frontal bossing , splenomegaly , repeated fever , prominent cheekbones, depression of the bridge of the nose, unusual prominence of maxillary anterior teeth Dr. A K Jain Human physiology for BDS fifth edition
WHITE BLOOD CELLS Leukocytes are also called white blood corpuscles. The fundamental job of the WBCs is to provide defense against Bacteria, Fungus, parasite and Virus 1.Total WBC count (TC): 4,000 to 11,000 cells/cu. mm of blood 2. Differential WBC count (DC): Polymorphonuclear granulocytes Mononuclear agranulocytes Neutrophils 60-70% Lymphocytes 25-33% Eosinophils 1-4% Monocytes 2-6% Basophils 0.25-0.5% D. Venkatesh Basics of medical physiology third edition
VARIATIONS IN THE COUNT OF WBC’s Leukocytosis is a condition where total count (TC) of WBC is > 11,OOO/ μl . In leukopenia , TC of WBC is <4000/ μl . FACTORS HELPING THE PROLIFERATION OF LEUKOCYTES For WBC proliferation, growth factors are required. These growth factors are: Interleukins : Interleukin-1,-3,-6 convert pleuripotent uncommitted stem cells to committed stem cells CSF-GM :Stimulates the production of neutrophils , monocytes , eosinophils , erythrocytes and megakaryocytes CSF-G : Stimulates the production of neutrophil CSF-M : Stimulates the production of monocytes Prostaglandins, cortisol , adrenocorticotropic hormone play an important role in control of leukopoiesis . D. Venkatesh Basics of medical physiology third edition
LEUKOPOIESIS : Leukopoiesis is the development of leucocytes.
NEUTROPHILS Size : 10- 14 µm diameter Nucleus : purple, multilobed Lobes : 2,3 up to 5 or more. Young cell—less lobes. Granules : fine, amphophilic / neutrophilic , have lytic enzyme Primary/ azurophilic / lysosomal –bacterial destruction. Secondary – lactoferrin – inhibits growth Functions - Most important function of the neutrophil is to attack and destroy the invading bacteria.
Neutrophilia : Neutrophilic leukocytosis is a condition where the differential count (DC) of neutrophil is> normal plus the TC is > normal. Physiological cause : exercise lactation pregnancy Pathological cause : acute pyogenic infection Neutropenia : In neutropenia , neutrophil count is < normal. Causes : typhoid and viral fever bone marrow depression D. Venkatesh Basics of medical physiology third edition
Functions : limit allergic intensity , eg Bronchial asthma, hay fever mild phagocytosis Eosinophilia : Eosinophilia is a condition where DC of eosinophil is greater than normal or absolute count of eosinophils is more than 500/ μl . allergic conditions parasitic infections Eosinopenia : injection Of corticosteroids D. Venkatesh Basics of medical physiology third edition
BASOPHILS Size : 10-14 µm diameter Nucleus : bilobed , S shaped Cytoplasm : basophilic, granular Granules : coarse, purple/ blue, plenty, contain Heparin, Histamine, Hyaluronic acid, protease Functions :liberate heparin which is anticoagulant, histamin produces allergic reaction Basophilia : chicken pox small pox tuberculosis influenza Basopenia administration of glucocorticoids
MONOCYTES Size : 10- 18 µm diameter (largest) Nucleus : pale , round/kidney shaped Cytoplasm : clear , pale blue , agranular Life span : 48-72 hrs in blood & 3 months in tissues. Functions : phagocytosis – 2 nd line of defense antigen presenting cells (APC). role in tissue repair D. Venkatesh Basics of medical physiology third edition
LYMPHOCYTES Size : 9-18 µm diameter Nucleus : heterochromatic nuclei Life span : 12-24 hours Small Lymphocytes ;The cells are 6–9 μm in diameter.They have ovoid or kidney shaped nucleus Nucleus is usually eccentrically placed and occupies about 90% of the cell area Large Lymphocytes ;The cells are 10–15 μm in diameter The nucleus is homogenous.Nucleus is usually oval or kidney shaped and eccentrically placed
PHYSIOLOGICAL VARIATIONS 1.Age : In infants -- 20,000 per mm 3 In children-- 10,000 to 15,000 per mm 3 2. Sex: slightly more in males. In females, increases during menstruation, pregnancy and parturition. 3. Diurnal variation: Min in early morning & max in afternoon. 4. Exercise: Increased 5. Sleep: Minimum. 6. Emotional conditions: like anxiety - count increased. 7. Pregnancy: Increased
Leukemias Leukemia is a malignancy (cancer) of the hematopoietic tissue, characterized by uncontrolled proliferation of abnormal white blood cells in the bone marrow and peripheral blood Leukemia can be (1) acute or (2) chronic . Acute myeloblastic (AML), Acute lymphoblastic (ALL), Chronic myeloid (CML), Chronic lymphocytic leukemias (CLL) ACUTE MYELOID LEUKEMIA – Malignant transformation of undifferentiated precursors of myeloid series WBC count upto 1 lakh Gingival hyperplasia is most common More than 30 % myeloblasts are present in blood and bone marrow
ACUTE LYMPHOBLASTIC LEUKEMIA – Malignant transformation of undifferentiated precursors of lymphoid series Common in young adults and children CHRONIC LYMPHOBLASTIC LEUKEMIA – Malignant transformation of well differentiated cells of lymphoid series Common in elder age group WBC counts upto 5 lakhs /mm cube CHRONIC MYELOD LEUKEMIA – Malignant transformation of well differentiated cells of the myeloid series Common in middle age Gingival hyperplasia is common
PLATELETS Small colorless, nonnucleated and moderately refractive bodies. Diameter is 2.5 microns (2 to 4microns) Volume is 7.5 cubic microns (7 to 8 cubic microns). Spherical or rod shaped and become oval or disc shaped when inactivated. Sometimes, the platelets are of dumb bell, comma, cigar or any other unusual shape. Normal platelet count is 2,50,000 (2,00,000 to 4,00,000)/ cubic mm of blood. Lifespan of platelets is 10 days. Platelets are destroyed by tissue macrophage system in spleen. Dr. A K Jain Human physiology for BDS fifth edition
PROPERTIES OF PLATELETS 1 . ADHESIVENESS When platelets come in contact with any wet and rough surface, these are activated and stick to the surface. The factors, which cause adhesiveness are thrombin, ADP, Thromboxane A 2 , calcium ions and Von Willebrand factor. 2. AGGREGATION (GROUPING OF PLATELETS) The activated platelets group together and the stickiness is due to ADP and thromboxane A 2 .
PHYSIOLOGICAL VARIATIONS 1 . Age: Platelets are less in infants (1,50,000 to 2,00,000/ cu mm) and reaches normal level at 3rd month after birth. 2. Sex: In females, it is reduced during menstruation. 3. High altitude: Platelet count is increased in high altitude. After meals: After taking food, the platelet count is increased DEVELOPMENT OF PLATELETS Platelets are formed from bone marrow. The pluripotent stem cell gives rise to the CFU-M. This develops into megakaryocyte . The cytoplasm of megakaryocyte form pseudopodium. A portion of pseudopodium is detached to form platelet, which enters the circulation . Dr. A K Jain Human physiology for BDS fifth edition
FUNCTIONS OF PLATELETS 1. ROLE IN BLOOD CLOTTING - responsible for the formation of intrinsic prothrombin activator. 2. ROLE IN CLOT RETRACTION - The cytoplasm of platelets contains the contractile proteins namely actin, myosin and thrombosthenin and are responsible for clot retraction. 3. ROLE IN PREVENTION OF BLOOD LOSS (HEMOSTASIS) a. Platelets secrete 5 HT, which causes the constriction of blood vessels. b. Due to the adhesive property, the platelets can seal the damage in blood vessels like capillaries. By formation of temporary plug also platelets seal the damage in blood vessels.
4.ROLE IN REPAIR OF RUPTURED BLOOD VESSEL - The platelet derived growth factor (PDGF) formed in cytoplasm of platelets is useful for the repair of the endothelium and other structures of the ruptured blood vessels. 5.ROLE IN DEFENSE MECHANISM - By the property of agglutination, platelets encircle the foreign bodies and kill them by the process of phagocytosis.
PATHOLOGICAL VARIATIONS Decrease in platelet count is called thrombocytopenia and it occurs in the following conditions: Immune thrombocytopenic purpura Infections- measles, HIV Bone marrow infiltration Disseminated intravascular coagulopathy (DIC) Pregnancy Aplastic anaemia Dr. A K Jain Human physiology for BDS fifth edition
The increase in platelet count is called thrombocytosis , occurs in the following conditions: 1. Allergic conditions 2. Asphyxia 3. Hemorrhage 4. Bone fractures 5. Surgical operations 6. Splenectomy 7. Rheumatic fever and 8. Trauma (wound or injury or damage produced by external force). Dr. A K Jain Human physiology for BDS fifth edition
HEMOSTASIS AND BLOOD COAGULATION: The variety of body mechanism which try to arrest bleeding is called hemostasis . Hemostasis is achieved by several mechanism : Vascular spasm or vasoconstriction Formation of platelet plug Formation of a blood clot as a result of blood coagulation Deposition of fibrous tissue in the clot and permanent closure of defect in blood vessel D. Venkatesh Basics of medical physiology third edition
Coagulation of blood is a vital physiological process . Immediately following vascular damage, platelet plug (temporary hemostatic plug) formation occurs at the site of injury that immediately stops bleeding . The definitive hemostasis is the coagulation of blood , Coagulation of blood occurs due to activation of clotting factors (coagulation proteins) that are normally present in their inactive form in plasma. Blood Coagulation
CLOTTING FACTORS- Coagulation of blood depends on a series of chemical reactions involving clotting factors. There are known 12 clotting factors that were depicted earlier as factors I to XIII (factor VI absent)
The formation of prothrombin activator requires 12 different coagulation factors. They are as under: Factor 1- fibrinogen : It’s a plasma protein and it is acted upon by thrombin to form insoluble fibrin clot. Absence of factor 1 is termed as afibrinogenmia Factor 2- prothrombin : its an inactive precursor of thrombin .It is formed in the liver with the help of vitamin K Factor 3- Thromboplastin :This converts prothrombin to thrombin in the presence of factors 5, 7 , 10 and calcium and phospholipids Factor 4 – Calcium : Ionic calcium is required for clotting.This is required for the formation of prothrombin activator, for the conversion of prothrombin to thrombin and formation of insoluble fibrin clot Factor 5- labile factor : This is required for the conversion of prothrombin to thrombin by tissue extract and plasma factors Factor 6- Absent
Factor 7 – stable factor ( proconvertin ): This is required for the formation of prothrombin activator from tissue extracts Factor 8- Antihemophilic factor A : This is required for the formation of prothrombin activator by tissue extract Factor 9- Christmas factor ( antihemophilic factor B ): This is needed for the formation of prothrombin activator from blood constituents. Factor 10- Stuart-power factor- This is also required for the formation of prothrombin activator Factor 11-Plasma thromboplastin antecedent Factor 12 –Hageman factor Factor 13- Fibrin stabilizing factor : This is a plasma protein which causes polymerization of soluble fibrin to produce insoluble fibrin
MECHANISM OF BLOOD COAGULATION Blood coagulation occurs in three major stages: Stage 1 : Activation of Stuart- Prower factor (formation of prothrombin activator) Stage 2: Formation of thrombin from prothrombin Stage 3: Formation of fibrin from fibrinogen
Activation of Stuart- Prower Factor (Factor X ) Activation of Stuart- Prower factor or factor X is the key to blood coagulation . Factor Xa activates prothrombin to form thrombin. Therefore, this process is also called prothrombin activation. This is achieved by two pathways: the intrinsic pathway and the extrinsic pathway
ABNORMALITIES OF COAGULATION Hemorrhagic disorders are broadly classified into inherited and acquired defects. 1. Acquired defects are more common than inherited defects and platelet defects are more common than the coagulation defects. 2. Deficiencies of factor VIII (hemophilia) and factor IX (Christmas disease) are more common inherited coagulation defects. 3. The common acquired defects are thrombocytopenia,vitamin K deficiency, disseminated intravascular coagulation and liver failure resulting in clotting defects.
CHEMICAL AGENTS TO PREVENT BLOOD CLOTTING—ANTICOAGULANTS 1. HEPARIN 2. COUMARIN DERIVATIVES 3 EDTA 4. OXALATE COMPOUNDS 5. CITRATES Some snake venom, peptone and hirudin (from leach) are also the known anticoagulants SUBSTANCES WHICH HASTEN BLOOD CLOTTING—PROCOAGULANTS 1. THROMBIN 2. SNAKE VENOM 3. EXTRACTS OF LUNGS AND THYMUS 4. SODIUM OR CALCIUM ALGINATE 5. OXIDIZED CELLULOSE
TESTS FOR CLOTTING ■ BLEEDING TIME - This is the time interval from oozing of blood after a cut or injury till arrest of bleeding. The normal duration of bleeding time is 3 to 6 minutes. It is prolonged in purpura . CLOTTING TIME-The time interval from oozing of blood after a cut or injury till the formation of clot is called clotting time. The normal duration of the clotting time is 3 to 8 minutes. And it is prolonged in hemophilia PROTHROMBIN TIME -The normal duration of prothrombin time is about 12 seconds. The prothrombin time is prolonged in deficiency of prothrombin and other factors like factors I, V, VII and X
APPLIED PHYSIOLOGY- BLEEDING DISORDERS: HEMOPHILIA- Hemophilia major is due to deficiency of factor 8 It is a sex- linked hereditary disease which occurs exclusively in males Females are carriers Clotting time is prolonged and bleeding time is normal in hemophilia Hemophilia A It is due to deficiency of factor VIII. It is an X-linked recessive hereditary disease Soft tissue hematomas and hemarthroses In mild to moderate cases, continuation of hemorrhage secondary to trauma or surgery is the feature.
Diagnosis Patients have prolonged Activated partial thromboplastin time (APTT ). Prothrombin time and bleading time are normal . Assay of factor VIII in plasma is diagnostic Treatment The treatment consists of transfusion of fresh blood (as on storage factor VIII is rapidly lost), or transfusion of factorVIII -concentrate . Fresh-frozen plasma and cryoprecipitate both contain factor VIII.
Christmas Disease (Hemophilia B) Christmas disease or hemophilia-B occurs due to deficiency of factor-IX ( antihemophilic factor-B or Christmas factor). This is a sex-linked recessive hemorrhagic disease . Treatment The specific treatment of hemophilia B is the replacement of factor IX . VITAMIN K DEFICIENCY – It is necessary for the formation of five clotting factors – prothrombin , factor 7, factor 9, factor 10 and protein C in the liver . Absence of vitamin K leads to deficiency of these factors and defective clotting.
von Willebrand Disease von Willebrand disease (vWD) is the most common inherited bleeding disorder that occurs due to deficiency of von Willebrand factor (vWF) Clinical Features Mucocutaneous bleeding , Epistaxis , easy bruising, hematoma, menorrhagia and GI bleeding are common. In severe cases patient suffer from hemarthroses and muscle hematomas . Diagnosis Increase in bleeding time which is a standard screening test for vWD .
CLINICAL CONSIDERATIONS OF BLOOD IN CONSERVATIVE DENTISTRY AND ENDODONTICS 1 .SICKLE CELL ANAEMIA: Sickle Cell Anaeima is a potential risk factor for pulpal necrosis in clinically intact permanent tooth . Asymptomatic pulpal necrosis resulting from infarction involve periapical and appear as radiolucent areas Suggested steps to be followed for the dental treatment of sickle cell anemia patients C onsulting the physician before performing dental procedures Avoding salicylates in pain management Avoiding elective dental surgical procedures Pulpal necrosis with sickle cell anaemia Shafers Textbook of oral pathology
THALASSAEMIA The bone marrow expansion affecting the maxilla leads to varying degrees of protrusion,spacing,rotation of anterior teeth and malocclusion. Teeth may be discoloured and have short roots( To be considered during root canal treatment) There is increased risk of caries,which might be due to reduced salivation due to deposition of iron in the salivary glands because of secondary haemochromatosis,which can additionally cause pain in glands Shafers Textbook of oral pathology Superior Repositioning of the Maxilla in Thalassemia -Induced Facial Deformity: Report of 3 Cases and a Review of the Literature
Erythroblastosis fetalis Teeth will have green, brown or blue hue by deposition of blood pigment in the enamel and dentin of the developing teeth. But here stain does not involve teeth or portions of teeth developing after cessation of hemolysis shortly after birth. Also ground sections of these teeth will be positive for bilirubin
HEMOLYTIC JAUNDICE H emolytic jaundice is common in newborn One of the manifestations of these disorders is the elevated serum levels of bilirubin ( hyperbiliru-binemia ) When hyperbilirubinemia occurs during the period of dental development, these teeth can develop a green coloration. Shafers Textbook of oral pathology Superior Repositioning of the Maxilla in Thalassemia -Induced Facial Deformity: Report of 3 Cases and a Review of the Literature
T hrombocytopenia Non-steroidal anti-inflammatory drug are contraindicated and the patient may be given acetaminophen for pain management . Post-operative antibiotics are advised as this will reduce the late bleeding due to the infection N erve -block anesthetic injections are contraindicated unless there is no better alternative . The finish line for crown preparations for these patients should be preferably supragingival , so as to reduce the chances of gingival bleeding In case of surgical procedures t he patients require infusion of 1 bottle platelet rich plasma prior to procedure and tranexamic acid post-operatively.
Endodontic Treatment in the Patients with Bleeding Disorders Non-surgical endodontic treatment is generally low risk for patients with bleeding disorders ’ Electronic apex locator is preferred over radiographic technique as it reduces the need of IOPA x-ray, which can traumatize the soft tissue during placement and lead to prolonged bleeding . The use of rubber dam is almost mandatory to prevent laceration of soft tissues . But care to be taken to minimize trauma to the soft tissues during placement of rubber dams clamps . High-speed vacuum evacuators and saliva ejectors can cause trauma to the floor of mouth thereby leading to haematoma formation. So they should be used very carefully in those patients. with a gauze swab in the floor of the mouth In surgical endodontic treatment the consultation of the patient’s hematologist should be considered
PAIN MANAGEMENT ; Dental pain can usually be controlled with a minor analgesic such as paracetamol (acetaminophen) in the patients with bleeding disorders NSAIDs produce a systemic bleeding tendency by reversibly inhibiting platelet cyclooxygenase The risk of systemic bleeding with NSAIDs is enhanced by concomitant use of alcohol or anticoagulants, and associated by conditions such as,liver disease, and other hemorrhagic diatheses (e.g., hemophilia , von Willebrand's disease)
ENDODONTIC TREATMENT CONSIDERATIONS LOCAL ANESTHESIA ; In the patients with bleeding disorders, the inferior alveolar nerve- block are contraindicated because of the risk of hematoma formation T here is an 80% chance that a patient with hemophilia will develop a hematoma following the administration of an inferior alveolar nerve block injection without prior factor VIII infusion . The Preoperative prophylactic coverage should be discussed with the patient’s hematologist prior to any local anesthesia in the floor of the mouth or lingual infiltration for the same reason Mental nerve block injection in the mandibular arch is considered safe Other local anesthetic techniques, such as intra- pulpal , intra- ligamentary , and buccal infiltration, are safer, The alternative techniques, including sedation with diazepam or nitrous oxide oxygen analgesia can be employed to reduce need of anesthesia . A Review on Endodontic Treatment in the Patients with Bleeding Disorders
H EMOPHILIA There is generally no contraindication for performing endodontic treatment in hemophiliac patients. but instrumentation and filling should never be done beyond the apical region of a vital tooth. Non-vital teeth should be treated at least 2 to 3 mm short of the radiographic apex. Severe haemophiliac patients endodontic treatment can be usually carried out under antifibrinolytic cover (usually tranexamic acid). Endodontic surgeries must be carefully planned ; Desmopressin and tranexamic acid are primary alternatives. Desmopressin can be given as a slow intravenous infusion over 20 min of 0.3-0.5µg/kg, 30 to 60 minutes prior to the surgical procedure. Intranasal administration as a spray of 1.5mg per ml is an alternative, Mild haemophiliacs can effectively undergo surgical endodontics without the need for factor replacements Endodontics for the haemophiliac , a multidisciplinary perspective
Systemically Tranexamic acid, is given in dose of 1 g , 4 times a day starting at least 1 day preoperatively for surgical procedures. Local use of fibrin glue and/or swish and swallow rinses of tranexamic acid before and after the procedure is a cost-effective solution. I nfection induces fibrinolysis and so antimicrobials such as amoxicillin 500 mg three times daily should be given postoperatively for a full course of 7 days to reduce risk of secondary haemorrhage . Endodontics for the haemophiliac , a multidisciplinary perspective
HEMOSTATIC AGENTS IN ENDODONTIC SURGERY Adequate hemostasis is a critical step in endodontic surgery. It facilitates the procedure and affects the success and prognosis of the operation. HEMOSTATIC AGENTS USED IN ENDODONTICs; Aluminum chloride Ferric Sulphate BotroClot Epinephrine Impregnated Gauze Electrocauterization Aluminum Chloride versus Electrocauterization in Periapical Surgery: A Randomized Controlled Trial
Aluminum chloride placed into the bone defect for 2 minutes and removed with the help of a dental curette and sterile saline Hemostatic Agents in Periapical Surgery: A Randomized Study of Gauze Impregnated in Epinephrine versus AluminumChloride Aluminum Chloride versus Electrocauterization in Periapical Surgery: A Randomized Controlled Trial Application of the aluminum chloride
Frozen paper point The paper point,is sprayed with endo frost spray and placed inside the root canal system beyond physiological terminus for about 20-30 seconds. The frozen paper point will constrict the blood vessels, allowing a clot to form more quickly and stop the bleeding. After removal of paper point the bleeding has stopped. Endo frost spray A simple technique for management of apical bleeding
PLATELET RICH FIBRIN PRF is a biomaterial derived from the patients own blood , containing a high concentration of platelets , leukocytes, and growth factors The applications of platelet-rich fibrin (PRF) in regenerative endodontics are numerous. Bains et al. employed it as the agent for repairing iatrogenic perforation of the pulpal floor of the mandibular first molar when used in combination with MTA PRF is ideal for the revascularization of immature permanent teeth with necrotic pulps by providing a scaffold rich in growth factors, enhancing cellular proliferation and differentiation Evidence of progressive thickening of dentinal walls, root lengthening, regression in the periapical lesion, and apical closure was reported by Shivashankar et al., following the use of PRF on a tooth with pulpal necrosis and open apex Platelet rich fibrin used in regenrative endodontics and current uses , limitations
PLATELET RICH PLASMA PRP (Platelet-Rich Plasma):PRP is also derived from the patient's blood and contains a high concentration of platelets and growth factors . In conservative dentistry and endodontics , PRP can be used similarly to PRF for tissue regeneration and wound healing.However , PRP is typically more liquid in consistency compared to PRF and may require activation with thrombin or calcium chloride before use . PRP is used in procedures such as bone grafting, sinus augmentation, and periodontal surgery to promote tissue regeneration and enhance wound healing. Platelet rich plasma and regenrative dentistry
CONCLUSION In conclusion, a comprehensive understanding of blood-related considerations in dentistry is essential for providing high-quality, safe, and patient-centered dental care. By incorporating appropriate techniques and precautions, dental professionals can ensure positive treatment experiences and contribute to overall patient health and well-being.
REFERENCES 1.Hemostatic Agents in Periapical Surgery: A Randomized Study of Gauze Impregnated in Epinephrine versus AluminumChloride Aluminum Chloride versus Electrocauterization in Periapical Surgery: A Randomized Controlled Trial 2.Endodontics for the haemophiliac , a multidisciplinary perspective 3.A Review on Endodontic Treatment in the Patients with Bleeding Disorders 4.Shafers Textbook of oral pathology 5.Superior Repositioning of the Maxilla in Thalassemia -Induced Facial Deformity: Report of 3 Cases and a Review of the Literature 6.D. Venkatesh Basics of medical physiology third edition 7.Dr. A K Jain Human physiology for BDS fifth edition 8.A simple technique for management of apical bleeding 9. Platelet rich fibrin used in regenrative endodontics and current uses , limitations