Loading...
Long Test in Oral Communication
Quiz by Elaine Joy R. Cruz
Customize this quiz to suit your class
Instantly translate to 100+ languages
Tag the questions with any skills you have. Your dashboard will track each student's mastery of each skill.
Give this quiz to my class
Make mcq quiz with 4 option in which one is correct -'10 Basis of Material Science • .....;;;";;;"~~;;,,;;,,,,;.;.,,;;,,,;,,;.;,.,------------ 6. Temporary materials: Some materials are meant to be placed in the oral cavity for a short period of time for different reasons. • Temporary crowns: While a permanent crown is prepared in the dental laboratory, the patient must wait for few days before it can be fabricated and cemented into place. Does patient experience any problems during this time period? If the tooth is vital (the pulp is alive), the patient is likely to experience pain and sensitivity while eating and drinking, also it looks unesthetic. What can be done to solve this problem? A temporary crown is placed before the patient leaves the clinic. It is constructed and luted in the same appointment in which the crown preparation is done. Temporary crowns are not very strong or esthetic but they serve adequately till the permanent crown is ready to be cemented. • Temporary restorations: Sometimes it is difficult to decide immediately the best line of treatment for a particular tooth. The exact condition of the pulp may not be obvious to the dentist from the patient's symptoms. A dentist removes all or part of the decay and then places a temporary restoration to have time to observe the behaviour of the pulp or to give the pilip time to heal before deciding the further treatment required. Classification based on Location of Fabrication 4,9 Materials can be classified based on the location of fabrication into: • Direct restorative materials. • Indirect restorative materials Direct restorative materials: They include those materials which are used to restore cavity preparations directly in the oral cavity (Box 1.5). Box 1.5: Examples of direct restorative materials Amalgam, composites, glass ionomer and other materials, which set by chemical reactions in the mouth. Indirect restorative materials: It includes those restorations which must be fabricated outside the mouth, indirectly on a cast/ model/ die, because their processing condition would harm oral tissues. Materials used in the construction of such prosthesis are called indirect restorative materials (Box 1.6). Box 1.6: Examples of indirect restorative materials Gold inlays, crowns of metal, ceramic and polymers, which are processed at elevated temperatures. Some indirect composite restorations can be processed under specific wavelength of light, e.g. Ceramage. Classification based on Longevity of Use 1. Permanent restorations: These restorations are not planned to be replaced for a particular time period. Though they are referred to as permanent, actually they are not, e.g. fillings, crowns, bridges and dentures do not last forever (Fig. 1.5). 2. Temporary restorations: These restorations are planned to be replaced in a short period of time, such as few days to weeks. For ~ Permanent C/) c c -.2 0 c- :;::; Cll co Interim ~ Q; 0 .8ll::1iJ C/) o~ Cll a:: c:=:J Temporary Time period Fig. 1.5: Diagram depicting the time period of use of a restoration. (Arrow in permanent restoration depicts that such restorations are not planned to be replaced for a long period of time.) Introducton to Dental Materials Dental materials Box 1.7: Characteristics of metals 1. High thermal and electrical conductivity 2. Ductility (pure metals are very soft and they can be bent without breaking) 3. Opacity (they do not transmit light) 4. Luster (they have a surface that strongly reflects light and appears bright and shiny) 5. They tend to dissolve to some extent in water or other aqueous solutions, producing cations. 6. All metals are white (actually gray) except for gold, which is yellow, and copper, which is reddish. 7. All metals are solid at room temperature except mercury, which is liquid at room temperature and is used with silver alloys as amalgam. 8. All metals have high melting temperatures because of high strength of the metallic bond that holds the atoms together. 3. Polymers 4. Composites Composites are mixtures of two or more of the first three classes in which the different components remain distinct from one another in the final structure. A common example is composite resin. Fig. 1.7a: Three-dimensional structure of iron (metal) Metals Metals are the oldest of the three classes of materials that have been used as dental materials. Metals are characterized by metallic bonds (Box 1.7) which will be discussed in the next chapter. Metals solidify with their atoms in a regular or crystalline arrangement (see Chapter 2), often in the form of a cube (Fig. 1.7a). example, temporary fillings done in a tooth during root canal treatment, which have to be replaced within 2-4 days during subsequent visits. They are used to protect the tooth and provide function till the final restoration is done. 3. Interim restoration: At times, dental treatment requires "long-term" definite temporary restorations or "interim" restorations. For examle, a 7-year-old child, met with trauma and fractured one of his central incisors. A large composite build- up may serve his immediate requirement until the root formation is completed and a permanent crown is placed. 5 Classification based on the Chemical Nature of the Material These are the atoms that make up a material and the way they are bonded together determine the properties of that materiaLS Weak bonds make for weak materials and vice versa (Table 1.4). Materials can be classified into different categories based on their primary atomic bonds (Fig. 1.6): 1. Metals 2. Ceramics Fig. 1.6: Classification of dental materials based on chemical nature 12 Basis of Material Science Box 1.9: Benefits of ceramics in dentistry 1. Many ceramic oxides are used as pigmenting agents. These oxides produce good range of colors. Due to this characteristic, we are able to match almost any tooth color with good esthetic results. 2. They are inert, i.e. not chemically reactive. This quality provides ceramics with good bio- compatibility. 3. Ceramic materials are translucent, like natural teeth. This translucency gives the ceramic crown a more natural appearance than any other dental material. Fig. 1.7b: Internal arrangement of tetrahedral structure of ceramic (silica) four large oxygen atoms surround smaller silicon atom Ceramics A ceramic is a compound formed by the union of a metallic and a non-metallic element (Box 1.8). Most of these materials are oxides, formed by the union of oxygen with metals such as silicon, aluminum, calcium and magnesium (Fig.1.7b). Ceramics may be simple or complex. Examples of simple ceramics are alumina and silica. Examples of complex ceramics are feldspar (potassium aluminum silicate) and kaolin (hydrated aluminum silicate). Ceramics may be crystalline or non- crystalline (i.e. amorphous). Porcelain is a specific type of ceramic used extensively in dentistry (Box 1.9). Box 1.8: Characteristics of ceramics 1. High melting points. 2. Brittleness, which means they cannot be bent or deformed (no sliding) to any extent without actually cracking and breaking. 3. They are poor conductor of heat and electricity. 4. They are chemically inert. 5. They have excellent esthetic result in terms of matching natural teeth. Fig. 1.8: Stucture of synthetic polymer Polymers They are the latest addition (early to mid- 1900s) to dental materials. Most of the polymers are nowadays synthesized by humans. Polymers are giant, long-chain organic molecules (Fig. 1.8). Polymers are characterized by covalent bonds within each molecule, giving them tremendous strength in a single direction. Try to break a nylon rope by pulling it! They are poor conductors of heat and electri- city. Most polymers have a structure containing thousands of carbon atoms linked together like beads on a string. Others, such as silicone polymers are formed with silicon-oxygen bonds. Introducton to Dental Materials Table 1.4: Characteristics of different materials 13 Characteristics Bond Properties Crystal structure Metals Metallic bonding High strength and hardness, high electrical and thermal conductivity BCC, FCC, or HCP unit cells Ceramics Ionic or covalent bonding, or both High hardness and stiffness, electrically insulating, refractory, and chemically inert Crystalline or amorphous Polymers Covalent bonding Low sensitivity, high electrical resistivity, and low thermal conductivity, strength and stiffness vary widely Amorphous and crystalline Composites Composites are combinations of any of the basic ceramic, metallic and polymeric materials (Box 1.10). Each material that makes up composites is called a phase. Their properties tend to be somewhere between those of their basic constituents and are used to enhance their performance, longevity and handling chracterstics. Box 1.10: Types of composites in dentistry 1. Ceramic - metallic composite: Tungsten carbide bur. 2. Metal - polymer composite: Die materials in dental laboratory. 3. Ceramic - polymer composite: Enamel, dentin, bone and restorative composites. A composite is a kind of "combination" of materials, which compliment each other. The properties lacking in one material are compensated by those of the other material. For example, restorative composite has two phases, namely resin and fillers. Teeth and bones are examples of natural composites. Enamel is a composite of hydroxyapatite (which is a ceramic material) and protein (which is a polymer). EVALUATION OF DENTAL MATERIALS Most manufacturers of dental materials maintain a quality assurance programme (As per international standard like ADA specifications) and materials are thoroughly tested before being released into the market for dental practitioner (Fig. 1.9). Laboratory Evaluations Most ADA/ ANSI specifications involve laboratory tests. The tests performed as per these specifications are useful but they all are performed in vitro, (carried out in the laboratory away from the clinical conditions) which have a lot of limitations in clinical practice.lO Clinical Notes 1. For example, most of the direct restorative materials are tested for their compressive strength but ultimately the material is subjected to a combination of compressive, tensile and shear stresses, which may decide the final success or failure of the material under masticatory load. 2. Similarly upper dentures mostly fracture along the midline because of bending. Hence a bending or transverse strength ~B-a-s-is-o-f-M-a-t-e-ria-I-S~c-ie-n-c-e-------------- ---------. test is far more meaningful for denture base materials than a compression test. Clinical Trials The majority of new materials are subjected to extensive clinical trials normally in co-operation with a dental college or hospital departments prior to their release. CONCLUSION As the number of available materials is going up, it is important that the dentist remains more aware about new products so that their judgement about the selection of material remains successful. Materials which have not been thoroughly evaluated should be avoided, specially with clinical dentistry falling under Consumer Protection Act (CPA). I Research and development I iI Manufacturer/analysis Ideal requirements for clinical use: Thermal, optical, mechanical, chemical, biological Available materials and their properties are evaluated Launch of new I product Choice and selection of material by the dentist Critical assessment based on clinical performance I I H feedback to IOral Manifestations of Viral Infections Viral infections can lead to a variety of oral manifestations, which may vary depending on the type of virus involved. Below are the key viral infections and their associated oral symptoms. --- 1. Herpes Simplex Virus (HSV) Infections Type: HSV-1 and HSV-2 Common Oral Manifestations: Primary Herpetic Gingivostomatitis: In children, presents as painful swelling and redness of the gums, with vesicular lesions on the lips, tongue, and hard palate. Recurrent Herpes Simplex: Cold sores (herpes labialis) often appear on the lips or around the mouth, and are painful and fluid-filled. Herpetic Whitlow: Infection of the fingers, often seen in healthcare workers. Clinical Features: Vesicular lesions that break to form ulcers Painful and burning sensations in affected areas Swollen lymph nodes Fever (during primary infection) Diagnosis: Direct immunofluorescence, PCR, or viral culture. --- 2. Varicella-Zoster Virus (VZV) Infections Type: Varicella (chickenpox) and Herpes Zoster (shingles) Common Oral Manifestations: Varicella: Enanthem (oral lesions) such as vesicular lesions on the hard palate, tongue, and lips, in conjunction with the characteristic skin rash. Herpes Zoster (Shingles): Unilateral painful oral lesions, often involving the hard and soft palate, and can extend to the tongue or buccal mucosa along the distribution of the trigeminal nerve. Clinical Features: Vesicular lesions that ulcerate Pain and discomfort in affected areas Fever, malaise, and headache (for chickenpox) Diagnosis: PCR, direct fluorescence antibody test, and clinical signs. --- 3. Human Papillomavirus (HPV) Infections Type: Multiple strains, including HPV types 16 and 18 Common Oral Manifestations: Oral Warts: Benign, non-painful growths typically found on the lips, palate, tongue, and floor of the mouth. Condyloma Acuminatum: Wart-like lesions in the mouth, often associated with genital HPV. Oropharyngeal Cancer: Certain high-risk HPV strains (e.g., HPV-16) are linked to cancers of the oropharynx, including tonsils and base of tongue. Clinical Features: Raised, fleshy, or cauliflower-like growths Rarely associated with pain or discomfort Diagnosis: Biopsy and PCR testing for HPV. --- 4. Coxsackievirus Infections Type: Hand, Foot, and Mouth Disease (HFMD) Common Oral Manifestations: Oral Ulcers: Painful, shallow ulcers typically seen on the soft palate, tonsils, tongue, and buccal mucosa. Vesicular Lesions: Small vesicles that ulcerate to form painful sores. Clinical Features: Red spots or vesicles that turn into ulcers Fever, sore throat, and malaise Rash and lesions on hands and feet Diagnosis: Clinical presentation and PCR. --- 5. Measles (Rubeola) Type: Paramyxovirus Common Oral Manifestations: Koplik Spots: Small, white or bluish-white spots seen on the buccal mucosa opposite the molars before the rash appears. Generalized Oral Ulceration: Following the appearance of Koplik spots, mucosal lesions may develop. Clinical Features: High fever, cough, and rash (starts on the face and spreads) Conjunctivitis Koplik spots as early indicators Diagnosis: Clinical signs and serology for measles antibodies. --- 6. HIV/AIDS Type: Human Immunodeficiency Virus Common Oral Manifestations: Oral Candidiasis: Fungal overgrowth in the mouth due to immunosuppression. Kaposi's Sarcoma: A form of cancer that appears as purple or brown lesions in the mouth, especially in the palate or gingiva. Oral Hairy Leukoplakia: White, hairy lesions on the lateral borders of the tongue, often associated with Epstein-Barr virus. Herpes Simplex and Zoster: Recurrent infections in the oral cavity. Clinical Features: Candidiasis: White plaques that can be scraped off Kaposi’s Sarcoma: Purple, macular lesions Hairy Leukoplakia: White, corrugated patches on the tongue Recurrent infections and oral ulcers Diagnosis: HIV testing, biopsy for Kaposi's sarcoma, and culture for candidiasis. --- 7. Influenza Virus Type: Influenza A and B Common Oral Manifestations: Pharyngitis: Sore throat and erythema of the oropharyngeal mucosa. Dry Mouth: Often secondary to fever and dehydration. Mucosal Erosions: Rare, but may occur in severe cases. Clinical Features: Fever, cough, sore throat, muscle aches, and headache Red or swollen tonsils and oral mucosa Diagnosis: Rapid influenza tests and PCR. --- 8. Epstein-Barr Virus (EBV) Type: Epstein-Barr virus Common Oral Manifestations: Oral Hairy Leukoplakia: White, asymptomatic, corrugated patches on the lateral borders of the tongue. Pharyngitis: Sore throat with swelling of tonsils. Oral Ulcers: Occasionally seen in association with infectious mononucleosis. Clinical Features: Fever, sore throat, and swollen lymph nodes (mononucleosis) Fatigue and malaise Diagnosis: EBV serology and PCR. --- 9. Rabies Virus Type: Rabies virus Common Oral Manifestations: Hydrophobia: Difficulty swallowing and fear of water. Increased Salivation: Resulting from dysfunction in the throat and jaw muscles. Clinical Features: Progressive neurological symptoms Paroxysms of pain or spasms in the throat and mouth Diagnosis: Clinical signs, rabies testing (saliva, CSF, or tissue biopsy). --- 10. Human Immunodeficiency Virus (HIV) Common Oral Manifestations: Oral Candidiasis: White, creamy lesions in the mouth, especially in immunocompromised individuals. Kaposi’s Sarcoma: Purple or red lesions on the palate and gingiva. Herpes Simplex: Recurrent oral lesions. Oral Hairy Leukoplakia: A condition linked with Epstein-Barr virus, presenting as white patches on the lateral borders of the tongue. --- Conclusion Oral manifestations of viral infections are varied and can provide valuable clues for diagnosing systemic viral diseases. Clinicians must consider the specific features and patterns of lesions in combination with other clinical signs for an accurate diagnosis. Some infections may also have long-term oral health implications, requiring management and prevention strategies.Long Test in Module 1-3LONG TEST IN ENGLISH 9LONG TEST IN NURSING INFORMATICSLONG TEST IN FBS NC IILONG TEST IN PHILOSOPHYLong Test in Personal Development