NBDHE Board Study Questions and Answers 100% correct, Exams of Dentistry

Download NBDHE Board Study Questions and Answers 100% correct and more Exams Dentistry in PDF only on Docsity! NBDHE Board Study Questions and Answers 100% correct A drug ending in the suffix 'pril is considered a A. antibiotic B.ACE inhibitor C. anti fungal D. beta antagonist - B. ACE inhibitor Which of the following is NOT considered to be a risk factor for a type 1 diabetic? A. diet B. genetics C. autoimmune D. environmental - A. diet Type 2 diabetes accounts for approximately what percentage of all cases of diabetes in adults? A. 25-30% B/ 35-40% C. 55-60% D. 90-95% - D. 90-95% Which of the following is NOT considered to be a risk factor for a type 2 diabetic? A. increased age B. obesity C. smoking D. physical inactivity - c. smoking What percentage of women with gestational diabetes are diagnosed with type 2 diabetes following their pregnancy? A. <5% B. 5-10% C. 20-25% D. 25-30% - B. 5-10% Untreated diabetes may result in all of the following EXCEPT: A. blindness B. cardiovascular disease C. kidney disease D. tinnitus - D. tinnitus -ringing of the ears Prediabetes is associated with all of the following except: a. Increased risk of developing type 2 diabetes b. Impaired glucose tolerance c. Increased risk of heart disease and stroke d. Increased risk of developing type 1 diabetes - D. increased risk of developing type 1 diabetes -persons with elevated glucose levels that do not yet meet the criteria for diabetes are considered to have prediabetes and are at increased risk for type 2 diabetes, not type 1 diabetics are at increased risk of heart disease if they also a. smoke b. have increased HDL cholesterol levels c. take aspirin D. consume increased fiber in diet - A. smoke Which of the following types of immunoglobulins is the most responsible for promoting allergic reactions? A. IgA B. IgD C. IgM D. IgE - D. IgE how to remember: "Eeeek, I had an allergic reaction" Which of the following types of immunoglobulins is located on the surface of most B- lymphocytes? A. IgA B. IgM C. IgD D. IgE - C. IgD Which of the following types of immunoglobulins does NOT cross the barrier between mother and infant in the womb? A. IgA B. IgM C. IgD D. IgE - D. Dentigerous cyst - D. Dentigerous cyst The most external layer of alveolar bone is the: A. Spongy bone B. Spicule bone C. Cortical bone D. Woven bone E. Cribriform plate - C. Cortical The first succedaneous tooth to erupt is the: A. Perm. max central incisor B. Prim. mand central incisor C. Perm. mand central incisor - C. perm. mand central incisor The glenoid fossa is an oval cavity or a depression in the A. maxilla, just anterior to the molar process B. temporal bone C. mandible D. occipital bone - B. temporal bone The erupted dentition of a normally developed 7- year-old child usually consists of A. 8 primary and 8 permanent teeth. B. 10 primary and 10 permanent teeth. C. 12 primary and 8 permanent teeth. D. 18 primary and 6 permanent teeth. E. 20 primary teeth. - D. 18 primary and 6 permanent teeth A common oral manifestation of Addisions disease is A. melanosis B. xerostomia C. glossodynia D. cotton-wool bone - A. melanosis An individual with mitral regurgitation will most likely suffer from which of the following? A. decrease heart rate B. fluid congestion in lungs C. peripheral edema D. ventricular arrythmias - B. fluid congestion in lungs The largest and longest cusp in posterior teeth is the: A. Mesiolingual cusp of max. 1st molar B. Distolingual cusp of Max. 1st molar C. Mesiofacial cusp of mand. 1st molar D. Distofacial cusp of mand. 1st molar - A. Mesiolingual cusp of maxillary 1st molar Which of the following teeth in the permanent dentition normally have trifurcations? A. Mand. molars only B. Mand. second premolars C. Mand. molars and Max. 1st premolars D. Max. molars and max. 1st preomars E. Max. 1st and 2nd molars and some max. 3rd molars - E. Max 1st and 2nd molars and some max. 3rd molars An individual with Addisions disease is most likely to experience which of the following? A. Decreased ACTH levels B. Hypoglycemia C. Water retention D. Weight gain - B. hypoglycemia Dry heat destroys organisms primarily by: A. Lysis B. Oxidation C. Precipitation of salts D. Dissolving of cell membranes E. Denaturation of proteins - E. denaturation of proteins Which of the following premolars frequently has only one pulp horn? A. Max. 1st premolar B. Mand. 1st premolar C. Max. 2nd premolar D. Mand. 2nd premolar - B. Mand. 1st premolar In what cell phase is the cell highly active and growing? A. anaphase B. interphase C. metaphase D. prophase - B. interphase Where is smooth muscle found in the body? A. heart B. attached to bone C. walls of hollow organs D. discs between vertebrae - c. walls of hollow organs A local anesthetic block is needed fot a debridement in the lower right quadrant. What is an anatomical landmark used when administering this injection? A. glossopalatine arch B. retromolar pad C. pterygomandibular raphe D. pharyngopalatine arch - C. pterygomandibular raphe Which of the following describes a wedge-shaped biochemical loss that often occurs on the cervical portion of the maxillary right canine and premolars? A. abrasion B. abfraction C. caries D. erosion - B. abfraction Which tooth does not have a transverse ridge? A. maxillary canine B. max. 1st premolar C. max. 1st molar D. Mand. 1st molar - A. Maxillary canine Which tooth from the permanent dentition erupts first? A. #5 B. #11 C. #20 D. #22 - D. #22 The type of epithelial tissue that is found in the oral cavity is called: A. stratified squamous B. simple columnar C. simple cuboidal D. pseudo-stratified columnar - A. stratified squamous Which of the following is considered the "silent killer" C. Globulomaxillary cyst D. Giant cell tumor - C. globulomaxillary cyst Tachycardia is characterized by an increase in: A. pulse rate B. blood pressure C. body temperature D. resporation - A. pulse rate During a periodontal evaluation, furcation involvement is detected on tooth #30. The nabers probe enters into the furcation area and pentrates through to the opposite side. There is no recession present. What class of furcation is this? A. Class 1 B. Class 2 C. Class 3 D. Class 4 - C. Class 3 Which of the following film sizes are used to examine permanent posterior teeth and for vertical bitewings? A. size 0 B. size 1 C. size 2 D. size 3 - C. size 2 A possible result of vitamin D deficiency is A. night blindness B. enamel hypoplasia C. glossitis D. oral leukoplakia - B. enamel hypoplasia Which of the following species of Streptococcus is predominantly found on hard tissues or teeth? A. Streptococcus mutans B. Streptococcus oralis C. Streptococcus salivaris D. Streptococcus mitis - A. Streptococcus mutans Immunity acquired by vaccination with toxoid is referred to as: A. Artificially acquired passive B. Artificially acquired active C. Naturally acquired passive D. Naturally acquired active - A. Artificially acquired passive A radiolucency around the crown of an unerupted tooth is referred to as a: A. Primordial cyst B. Periapical granuloma C.Residual cyst D. Dentigerous cyst - D. Dentigerous cyst The term overbite describes: A. Horizontal relationship of anterior teeth B. Vertical overlapping of anterior teeth C. Posterior crossbite thats present in some patients D. Rotation or anuglation of isolated teeth - B. The vertical overlapping of the anterior teeth The minimum distance the operator should stand from the tube head while exposing films is: A. 2ft B. 4ft C. 6ft D. 9ft - C. 6ft The annual radiation maximum permissible dose for occupationally exposed workers is: A. 0.5 mxv B. 5 msv C. 50 msv D. 500 msv - C. 50 msv The administration of oxygen is indicated in most medical emergencies. During which of the following medical emergencies is oxygen NOT indicated? A. Hyperglycemica B. Hyperventilation C. Syncope D. Asthma - B. Hyperventilation Which organization gives individuals the right to keep their group health insurance benefits? A. COBRA B. OSHA C. HIPAA D. CDC - A. COBRA Which terms refers to the destruction of ALL bacteria? A. bacteriostatic B. substantivity C. bactericidal D. disinfectant - C. bactericidal What is the classification of a furcation with moderate bone loss, where a Nabers probe can enter the furcation, but cannot pass through the roots? A. class 1 B. class 2 C. class 3 D. class 4 - B. class 2 What would be the amount of fluoride supplement needed for a 4-year-old child living in a community where the fluoride concentration is 0.5 ppm? A. none B. 0.25 mg/day C. 0.5 mg/day D. 1.0 mg/day - B. 0.25 mg/day Which of the following is not a compound used to fluoridate water? A. sodium fluorosilicate B. stannous fluoride C. hydrofluorosilicis acid D. sodium fluoride - B. stannous fluoride Which area-specific Gracey curette is used to scale direct linguals and facials of posterior teeth? A. Gracey 1/2 B. Gracey 7/8 C. Gracey 15/16 D. Gracey 17/18 - B. Gracey 7/8 There is a 3mm pocket on the direct lingual of tooth #30. Thre is also 4mm of recession on the direct lingual. What is the CAL for tooth #30. A. 6mm B. 7mm C. 4mm Smokers have an increased risk of developing periodontal disease. Smokers are also at a higher risk of developing apthous ulcers. A. Both true B. Both false C. First true, second false D. first false, second true - C. first true, second false Which biostatistics sample gives an equal chance of appearing and reduces the chance of bias? A.Random B. Judgement C. Systematic D. Convenience - A. random which vein of the head and neck is formed by drainage of venous blood from the pterygoid plexus? A. Lingual vein B. Facial vein C. Common facial vein D. Maxillary vein - D. maxillary Ulcers on attached gingiva can be a sign of? A. Candida albicans B. Measles C. Herpes D. Addisons disease - C. herpes Which conditions presents with a decreased caries risk? A. Down syndrome B. Drug addict C. Cancer D. Xerostomia - down syndrome Which type of seizure is defined as continuous convulsions lasting more than 5 mins? A. Petit mal B. Aura C. Grand mal D. Status epilepticus - D. Status epilepticus Your patient has a spinal cord injury that left them with minimal functioning ability on their own. They will need help with their oral care because they only have partial shoulder and partial elbow mobility. What part of their spine was injured? A. T-1 B. C-5 C. C-7 D. C-4 - B. C-5 Which of the following is not an additive that will modify the working time of gypsum products? A. Adding borax B. Mixing with warm water C. Adding sodium chloride D. Adding potassium sulfate - C. Adding sodium chloride Which cement needs to be mixed on a cool glass slab? A. Polycarboxylate cement B. Glass ionomer cement C. Zinc phosphate cement D. Zinc-oxide eugenol cement - C. Zinc phosphate -zinc phosphate goes through an exothermic reaction during mixing and therefore needs to be mixed on a cool glass slab Which principal of the code of ethics deals with the practitioner and means 'do not harm'? A. Nonmaleficence B. Veracity C. Justive D. Confidentiality - A. Nonmaleficence Which of the following is a cell of the periodontal ligament that is responsible for collagen synthesis and degradation? A. Cementoblasts B. Fibroblasts C. Osteoblasts D. Osteoclasts - B. Fibroblasts Which of the following is NOT related to CAMBRA? A. 1-2 incipient caries in the last year B. Increased salivary flow C. Topical fluoride choices D. low socioeconomic status - B. Increased salivary flow -the caries assessment tool was developed in formats for use by dental providers for patients 0 to 5 and patients age 6 through adult. The assessment tool is a part of an overall approach to prevent and treat caries. After you dismiss your patient and are transferring and processing instruments all would be required EXCEPT: A. carry instruments in a safe container to transport B. wear gloves C. wear mask and safety googles D. clinic jacket - C. wear gloves and safety googles Which side of the instrument is placed on the stone for sharpening? A. Back B. Terminal Shanks C. Junction of the face and lateral surface D. Junction of the back and lateral surface - C. Junction of the face and lateral surface Which type of drug is used to treat MRSA? A. Anticholinergic meds B. Sulfa-based meds C. Antiseptic meds D. Antifungal meds - B. Sulfa-based drugs Washing your hands between patients should be done for: A. 10 seconds B. 15 seconds C. 30 seconds D. 45 seconds - D 45 seconds If a patient has gingivitis, the reason for the edema is due to: A. inorganic irritant B. an organic irritant C. toxins produced from biofilm D. acids produced by biofilm - C. toxins produced from biofilm Iron supplements are frequently recommended for all of the following EXCEPT: A. pregnant women B. infants and toddlers A. Actinomyces B. Lactobacillus C. Clostridium tetani D. Streptococcus mutans - B. Lactobacillus Note- actinomyces is associated with root caries Which two monosaccharides make up lactose? A. glucose and glucose B. glucose and fructose C. galactose and fructose D. glucose and galactose - D. glucose and galactose What is the deficiency for vitamin B3, niacin? A. Pellagra B. Beri beri C. Cheilosis and glossitis D. Pernicious anemia - A. Pellagra When doing an assessment with only a mouth mirror and lighting, you are using what kind of examination method? A. type 1 B. type 2 C. type 3 d. type 4 - c. type 3 -this is also called an inspection what bone is the non-articulated bone at the midline inferior to the mandible that also shows up on panaramic xrays? A. vomer bone B. zygomatic bone C. hyoid bone D. lacrimal bone - c. hyoid bone Which of the following conditions does NOT require premedication? A. artificial heart valves B. artificial joint replacements C. heart shunts D. mitral valve prolapse - D. mitral valve prolapse no longer requires premedication What is the ability to undergo change of form without breaking? A. adhesion B. ductility C. creep D. Inhibition - B. ductility Which tooth is considered succedaneous? A. 16 B. 24 C. 30 D. 31 - B. 24 -succedaneous means it replaces a primary tooth A 62-year-old female patient has a history of taking fen-phen and has an artificial heart valve. The patient is also allergic to sulfa drugs. Which option is correct? A. No premedication needed B. Clindamycin 600 mg- 1 hr before C. Vancomycin 600 mg- 1 hr before D. Amoxicillin 2000 mg- 1 hr before - D. Amoxicillin 2000 mg- 1 hr before Which blood type is the universal donor? A. A B. B C. AB D. O - D. O Which blood type is the universal recipient? A. A B. B C. AB D. O - C. AB All of the following are related to caries except? A. Actinomyces viscosus B. Streptococcus mutans C. Streptococcus mitis D. Streptococcus sobrinus - C. Streptococcus mitis -associated with endocarditis, not caries. the rest are associated with caries. All of the following are used to treat HIV except: A.Carbamazepine B. Zidovudine C.Didanosine D. Zalcitabine - A. carbamazepine -this is an anticonvulsant A hygienist is doing an extra-oral examination and asks the patient to swallow. She detects something bilateral of the midline of the cervix. what could she have detected? A. submental lymph nodes B. thyroid gland C. Deep cervical lymph nodes D. Supraclavicular lymph nodes - B. thyroid gland -this is located at the midline of the cervix What instrument will be used to scale the mesial of the distal root of tooth #19? A.Gracey 11/12 B. Gracey 13/15 C. Posterior sickle scaler D. 11/12 explorer - A. Gracey 11/12 A deficiency of ascorbic acid is called scurvy. Women taking oral contraceptives may avoid scurvy related problems by eating more fruits and vegetables. A. The statement is true but the reason is not related B. The statement is true and the reason is related C. The statement is false and the reason is not related D. The statement is false but the reason is true - B. The statement is true and the reason is related A 5-year-old patient has just moved from a non-fluoridated region to a fluoridated region to go to school. Currently this patient uses fluoridated toothpaste. What would your recommendation be for additional fluoride? A 0.05% sodium fluoride rinse B. 0.5mg.day supplement C. 0.25 mg/day supplement D. Ask the patients mother what the concentration of fluoride in ppm in the water supply is before processing with a recommendation - D. ask mother C. Superior deep cervical D. Inferior deep cervical - B. Submental lymph nodes Which of the following drugs would best treat a MRSA infection? A. Amoxicillin B. Clindamycin C. Vancomycin D. Cephalexin - C. Vancomycin is a very strong antibiotic and can treat MRSA All of the following are white oral lesions EXCEPT: A. Leukoplakia B. Aspirin burn C. Pseudomembraneous candidiasis D. Erythematous candidiasis - D. erthematous candidiasis -red Which of the following is the proper order to place a sealant? A. Dry, clean, etch, isolate, rinse, dry, apply B. Clean, rinse, isolate, etch, rinse, dry, apply C. Clean, dry, rinse, etch, isolate, rinse, dry, apply D. Clean, rinse, isolate, rinse, dry, etch, apply - B. Clean, rinse, isolate, etch, rinse, dry, apply All of the following are liners EXCEPT: A. Varnish B. Calcium hydroxide C. Zinco-oxide/eugenol D. Zinc phosphate - D. Zinc phosphate is a cement Which of the following is an antimicrobial agent that can be found in toothpaste? A. Sodium pyrophosphate B. Triclosan C. Potassium nitrate D. Strontium chloride - B. triclosan -sodium pyrophosphate is for dentinal hypersensitivity All of the following are measures of central tendency EXCEPT: A. Range B. Mean C. Median D. Mode - A. Range -range is a measure of dispersion, not central tendency What is a disease that occurs regularly in a population as a matter of course? A. Pandemic B. Endemic C. Morbidity D. Epidemic - B. Endemic What is the correct direction of blood flow through the heart? - B. Right atrium->tricuspid valve->right ventricle->pulmonary artery (deoxygenated blood) ->lungs -> pulmonary vein (oxygenated blood)-> left ventricle -> mitral valve -> left atrium -> aorta Which of the following are characteristic signs of chronic fluoride intoxication? A. Upset stomach B. Osteosclerosis of bones C. Fever D. Diarrhea E. Dental fluorosis - B. Osteosclerosis of bones Systemic fluoride reduces caries by: A. Increasing hardness of enamel B. Decreasing hardness of enamel C. Reducing solubility rate of enamel D. Converting fluorapatite to hydroxyapatite - c. Reducing the solubility rate of enamel Nicole and Hannah, the hygienists, are in the process of examining five classrooms of children to assess both their past and present dental decay history. They are using an index designed for this purpose. Their findings are much higher than those previously reported, both for this population and for similar ones. Which type of epidemiological study are they conducting? A. Cross-sectional B. Descriptive C. Prospective D. Experimental E. Historical - D. Descriptive -a descriptive study helps to determining the amount of disease in a given population by asking several questions. This can lead to hypotheses about the cause and prevention of disease. These hypotheses can be grouped into two categories: observational and experimental. Which term describes the ratio of affected individuals to well individuals in a community? A. Natality B. Mortality C. Vital Index D. Morbidity - D. Morbidity The dentist has diagnosed and recommended specific treatment for a patient of record and remains on the premises while the patient is being treated. What is this type of dental supervision? A. General supervision B. Direct supervision C. Indirect supervision D. Personal supervison - C. Indirect supervison The ethical rules and principals of professional conduct for the practice of dentistry are set in the ADA's publication entitled, Principles of Ethics and Code of Professional Conduct. Which of the following is not an ethical principle found in the code? A. Justice B. Autonomy C. Self-esteem D. Beneficence - C. Self-esteem Which indices would most likely be used in assessing the prevalence of periodontal disease in a population? A. Gingival Index B. Periodontal Index C. PMA Index D. Plaque INdex - B. Periodontal Index The periodontal disease index is a/an ___ index A. Reversible B. Irreversible C. Both reversible and irreversible D. Neither reversible or irreversible - C. Both reversible and irreversible -it is both because it measures gingivitis and periodontitis separately. Which index is used to measure oral debris? A. Decayed, Missing and Filled teeth (DMFT) B. Plaque Index (PI) A. Viral infection B. Bacterial infection C. fungal infection D. parasitic infection - B. bacterial infection A type of cellulitis that involves inflammation of the tissues of the floor of the mouth which often occurs following infection of the roots of the teeth (such as tooth abscess) or after mouth trauma is called: A. Angioedema B. Vincent's angina C. Ludwig's angina D. Ranula - C. Ludwigs Angina What are very small purpura spots called? A. pimples B. petechiae C. ecchymosis D. varicose veins - B petechiae The most common cause of facial weakness that comes on suddenly is referred to as: A. Polio B. Bell's Palsy C. Trigeminal nerualgia D. Multiple sclerosis - B. Bells palsy bones affected by fibrous dysplasia usually have which of the following characteristic appearance on an radiograph? A. Lesions are radiolucent "cotton-wool" appearance B. Saucer-shaped radiolucency C. Radiopaque "ground glass" appearance D. unilocular or multilocular - C. radiopaque "ground glass" appearance What is the most common location for mandibular tori? A. Retromolar pad B. On lingual surface of mandible, most often premolar region C. On lingual surface of mandible, inferior to mylohyoid ridge D. Along midline of hard palate - B. on lingual surface of mandible, most often premolar region All of the following are clinical features of a central ossifying fibroma EXCEPT? A. Slow growing expansive lesion B. occurs most often in maxilla C. asymptomatic D. common in young adults around 35 years - B. most often in maxilla -they are most often found in the mandible around premolars and molars Which of the following is an example of an ASA II classification? A. Uncomplicated pregnancy B. Uncontrolled epilepsy C. Controlled angina pectoris D. Controlled insulin-dependent diabetic - A. uncomplicated -the rest are asa 3 If the mask used for emergency treatment becomes fogged when oxygen is delivered to a patient, it indicates which of the following? A. Flowmeter set too high B. Mask doesn't fit correctly C. Tank is empty D. Patient has started breathing - D. Patient has started breathing Bruising associated with physical abuse is often what color? A. red and purple B. green C. green and yellow D. red, green, yellow, brown - D. red green yellow and brown Dentifrices that contain soluble pyrophosphates or zinc chloride are labeled: A. Antigingivitis B. Antibiofilm C. Antisensitivity D. Antitarter - D. Antitarter Which of the following influences motivation on a short term basis? A. Pain B. Cost C. Malodor D. Esthetics - A. pain Which of the following methods of sterilization requires the longest cycle? A. Moist heat B. dry heat C. chemical vapor D. ethylene oxide - D. ethylene oxide Which of the following applies to moist heat sterilization? A. Uses steam under pressure B. Safe for all instruments C. prevents corrosion of instruments D. penetrates oils and powders - A. uses steam under pressure Which of the following is a pharmacological property of nitrous oxide? A. sour odor B. amber in color C. explosive D. inorganic - D. inorganic Approximately how long does it take for a patient to feel the changes in the level of the flow of gases when nitrous oxide is administered? A. 5-10 seconds B. 20 seconds C. 30-60 seconds D. 2 mins - C. 30-60 seconds The disease that affects the myelin sheath and results in fatigue and numbness is: A. muscular dystrophy B. multiple sclerosis C. parkinsons D. bells palsy - B. multiple sclerosis When sealants are applied correctly there is a decrease development of new carious lesions. There is also a decreased progression of pre-existing carious lesions. A. both true B. both false C. first true, second false D. first false, second true - A. both true Which of the following is the principal feature of placing a sealant successfully? A. High viscosity material B. Adequate retention C. An added colorant to make appearance different D. Use of rubber dam - A warmer climate will have a higher concentration level of fluoride and a colder climate will have a lower concentration level. A. Both true B. Both false C. First true, second false, D. First false, second true - B. Both false -opposite.think of it this way-if its warmer, the water will evaporate, so the fluoride in water will be lower Hairy tongue is a condition in which the patient has an increased accumulation of keratin on which papillae? A. Fungiform B. Filliform C. Circumvallate D. Folate - B. Filliform -way to remember-"Phil" is hairy. -filliform Which of the following has the function to surround and support the roots of the teeth? A. PDL B. Cementum C. Gingiva D. Alveolar bone - D. Alveolar bone Which of the following is the most sensitive to radiation? A. Muscle B. Bones C. Reproductive organs D. Nervous tissue - C. Reproductive organs -Note: nervous tissue is the least sensitive, followed by muscle. Which of the following muscles allows you to smile and laugh? A. Risorius B. Levator anguli muscle C. Buccinator D. Zygomaticus - D. Zygomaticus When checking Angle's classification, the hygienist notes that the buccal groove of the mandibular first molar is distal to the mesiobuccal cusp of the maxillary first molar. Tooth #8 is inclined lingually. What occlusion does this patient have? A. Class 1 B. Class 2, Division 1 C. Class 2, Division 2 D. Class 3 - C. Class 2, Division 2 Angular cheilitis is a result of a deficiency of which vitamin? A. Riboflavin B. Niacin C. Vitamin C D. B12 - A. Riboflavin-B2 Which liner stimulates the formation of reparative dentin? A. Eugenol B. Zinc phosphate C. Calcium hydroxide D. Glass ionomer - C. Calcium hydroxide Which type of hepatitis is the most asymptomatic? A. Hep A B. Hep B C. Hep C D. Hep D - C. Hep C Which gland produces the largest percentage of saliva? A. Parotid B. Submandibular C. Sublingual D. Minor salivary galnds - B. Submandibular -produces 65% of total saliva Parotid produces 25% and sublingual produces 10% In which tooth structure are the Korff's fibers located? A. Primary Dentin B. Secondary Dentin C. Mantle Dentin D. Acellular Dentin - C. Mantle Dentin