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OMSB Dentist practice questions

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Question 1Dentistry

A 45-year-old patient reports sharp, fleeting pain in the lower right molar region triggered by cold drinks and lasting only a few seconds after the stimulus is removed. The tooth is vital, percussion is non-tender, and there is no spontaneous night pain. What is the most likely diagnosis?

  1. Irreversible pulpitis
  2. Pulpal necrosis
  3. Reversible pulpitis Correct answer.
  4. Acute apical periodontitis

Explanation

Reversible pulpitis produces sharp pain provoked by thermal stimuli that resolves quickly once the stimulus is removed, and the pulp remains vital with no spontaneous pain. Irreversible pulpitis is characterized by lingering pain, spontaneous pain, or night pain. The absence of percussion tenderness and spontaneous symptoms supports a reversible, not periapical or necrotic, process.

Question 2Dentistry

Which local anesthetic agent is contraindicated in a patient with a documented true allergy to ester-type anesthetics but is safe to use with amide-type agents?

  1. Articaine Correct answer.
  2. Procaine
  3. Benzocaine
  4. Tetracaine

Explanation

Articaine is an amide-type local anesthetic and is therefore not cross-reactive with esters, making it a suitable choice when an ester allergy is documented. Esters such as procaine, benzocaine, and tetracaine share a para-aminobenzoic acid metabolite that can trigger allergic reactions. Cross-reactivity between ester and amide groups is generally not expected.

Question 3Dentistry

A patient with a history of infective endocarditis and a prosthetic heart valve requires extraction of a periodontally involved molar. According to current antibiotic prophylaxis guidance, which regimen is most appropriate?

  1. Clindamycin 600 mg orally one hour before the procedure
  2. Amoxicillin 2 g orally one hour before the procedure Correct answer.
  3. No prophylaxis is needed for dental extraction
  4. Amoxicillin 500 mg three times daily for seven days after the procedure

Explanation

Patients with prosthetic heart valves or prior infective endocarditis are among the highest-risk groups for whom antibiotic prophylaxis before invasive dental procedures is recommended. The standard regimen is a single 2 g oral dose of amoxicillin 30 to 60 minutes before the procedure. Prolonged post-procedural courses are not recommended for prophylaxis.

Question 4Dentistry

Which radiograph is most appropriate as the initial imaging modality for assessing alveolar bone loss in a patient with generalized chronic periodontitis?

  1. Bitewing radiographs Correct answer.
  2. Cone-beam computed tomography
  3. Panoramic radiograph
  4. Periapical radiographs

Explanation

Horizontal bitewing radiographs are the modality of choice for detecting and monitoring alveolar bone loss because they show the crestal bone and interproximal areas with minimal distortion. Periapicals supplement but do not replace bitewings for this purpose. Panoramic and CBCT images are not the first-line choice for routine periodontal bone assessment.

Question 5Dentistry

A 7-year-old child presents with a permanent maxillary central incisor that is unerupted while the contralateral incisor erupted at age 6. The most common cause of delayed eruption of a single permanent maxillary central incisor is which of the following?

  1. Cleidocranial dysplasia
  2. Premature loss of the primary incisor
  3. Supernumerary tooth or odontoma Correct answer.
  4. Hypothyroidism

Explanation

A supernumerary tooth (mesiodens) or odontoma is the most frequent local cause of delayed or failed eruption of a single permanent maxillary central incisor. Local mechanical obstruction should be excluded radiographically before systemic causes are considered. Systemic conditions usually affect multiple teeth symmetrically.

Question 6Dentistry

During administration of an inferior alveolar nerve block, the patient suddenly reports a metallic taste, palpitations, and tinnitus immediately after the injection. What is the most likely cause?

  1. Allergic reaction to the vasoconstrictor
  2. Needle breakage in the pterygomandibular space
  3. Intravascular injection of local anesthetic Correct answer.
  4. Hematoma formation in the retromolar region

Explanation

Metallic taste, palpitations, and tinnitus immediately after injection are classic signs of inadvertent intravascular administration, most often into the inferior alveolar vessels. These symptoms reflect systemic absorption of local anesthetic and epinephrine. Aspiration before and during injection helps prevent this complication.

Question 7Dentistry

Which of the following is the most reliable clinical indicator of successful pulpal anesthesia during endodontic treatment?

  1. Absence of bleeding from the access cavity Correct answer.
  2. Patient report of lip numbness
  3. Absence of pain on access preparation
  4. Positive response to cold testing

Explanation

Absence of bleeding from the access cavity indicates that the pulp has been anesthetized and devitalized sufficiently for instrumentation. Lip numbness reflects soft tissue anesthesia but does not guarantee pulpal anesthesia. Cold testing and pain on access are less reliable indicators during active treatment.

Question 8Dentistry

A patient presents with a firm, fluctuant swelling of the floor of the mouth that elevates the tongue and threatens the airway. Which space infection is most likely involved?

  1. Ludwig angina (bilateral submandibular, sublingual, and submental spaces) Correct answer.
  2. Submental space
  3. Canine space
  4. Buccal space

Explanation

Ludwig angina is a rapidly spreading cellulitis involving the submandibular, sublingual, and submental spaces bilaterally, causing floor-of-mouth elevation and airway compromise. It is a surgical emergency requiring airway management and urgent incision and drainage. Isolated single-space infections do not produce this bilateral, floor-of-mouth presentation.

Question 9Dentistry

Which of the following is the most common cause of halitosis of intraoral origin?

  1. Systemic ketoacidosis
  2. Chronic sinusitis
  3. Volatile sulfur compounds from bacterial degradation in the oral cavity Correct answer.
  4. Gastroesophageal reflux

Explanation

The majority of halitosis cases are intraoral, caused by anaerobic bacteria producing volatile sulfur compounds from protein degradation on the tongue dorsum and periodontal pockets. Extraoral causes such as reflux or sinusitis account for a minority of cases. Treatment focuses on tongue cleaning and periodontal therapy.

Question 10Dentistry

A 30-year-old patient has a deep carious lesion on a mandibular first molar with a large pulpal exposure and a history of spontaneous pain. Which treatment is most appropriate?

  1. Root canal treatment Correct answer.
  2. Pulpotomy
  3. Indirect pulp capping
  4. Direct pulp capping

Explanation

A large exposure with spontaneous pain indicates irreversible pulpitis, for which root canal treatment is the appropriate definitive therapy. Direct and indirect pulp capping are indicated for reversible pulpal inflammation without spontaneous symptoms. Pulpotomy is generally a pediatric or vital-pulp therapy option, not the definitive adult treatment for irreversible pulpitis.

Question 11Dentistry

Which tooth is most commonly affected by dens invaginatus?

  1. Maxillary central incisor
  2. Maxillary lateral incisor Correct answer.
  3. Mandibular canine
  4. Mandibular first molar

Explanation

Dens invaginatus most frequently affects the maxillary lateral incisor because of its developmental anatomy and invagination of the enamel organ. It can predispose the tooth to caries and pulpal infection. Other teeth are much less commonly involved.

Question 12Dentistry

A patient with type 2 diabetes and poorly controlled HbA1c presents with recurrent periodontal abscesses and rapid attachment loss. Which factor best explains the increased periodontal risk?

  1. Reduced inflammatory cytokine production
  2. Increased salivary flow
  3. Impaired neutrophil function and advanced glycation end products Correct answer.
  4. Increased collagen synthesis

Explanation

Poorly controlled diabetes impairs neutrophil chemotaxis and phagocytosis and increases formation of advanced glycation end products, which amplify inflammation and tissue breakdown. These mechanisms drive rapid periodontal destruction and recurrent abscesses. Diabetes does not reduce salivary flow or enhance collagen synthesis in a protective way.

Question 13Dentistry

Which of the following best describes the rationale for using a resin-modified glass ionomer as a base under a composite restoration in a deep cavity?

  1. It provides superior esthetics
  2. It has higher compressive strength than amalgam
  3. It bonds chemically to composite without an intermediate layer
  4. It releases fluoride and tolerates moisture while providing thermal insulation Correct answer.

Explanation

Resin-modified glass ionomer releases fluoride, tolerates moisture during setting, and provides thermal and pulpal insulation, making it useful as a base in deep cavities. It is not chosen for esthetics or high compressive strength. It requires appropriate surface treatment before composite placement.

Question 14Dentistry

A patient reports that a recently placed amalgam restoration feels high on biting. Which of the following is the most appropriate immediate management?

  1. Adjust the occlusion and recheck with articulating paper Correct answer.
  2. Reassure the patient and review in six months
  3. Prescribe antibiotics
  4. Replace the restoration

Explanation

A high restoration should be adjusted by identifying premature contacts with articulating paper and selectively reducing them. Replacement is unnecessary if the restoration is otherwise sound. Antibiotics have no role, and delaying review risks continued occlusal trauma.

Question 15Dentistry

Which of the following is the recommended first-line treatment for a localized chronic periodontitis lesion with a probing depth of 6 mm and bleeding on probing?

  1. Immediate periodontal surgery
  2. Scaling and root planing with oral hygiene instruction Correct answer.
  3. Extraction of the tooth
  4. Systemic antibiotics alone

Explanation

Non-surgical periodontal therapy with scaling and root planing plus oral hygiene instruction is the first-line treatment for chronic periodontitis. Systemic antibiotics are considered adjunctive only in specific situations and not as monotherapy. Surgery and extraction are reserved for cases that do not respond or for advanced disease.

Question 16Dentistry

Which of the following is a characteristic radiographic feature of a dentigerous cyst?

  1. Well-defined radiolucency attached to the cementoenamel junction of an impacted tooth Correct answer.
  2. Sunburst periosteal reaction
  3. Ill-defined radiolucency at the apex of a non-vital tooth
  4. Ground-glass bone appearance

Explanation

A dentigerous cyst appears as a well-defined radiolucency surrounding the crown and attaching at the cementoenamel junction of an unerupted or impacted tooth. It is the most common developmental odontogenic cyst. The other options describe periapical pathology, osteosarcoma, and fibrous dysplasia, respectively.

Question 17Dentistry

A 12-year-old patient has a mandibular first molar with a large occlusal carious lesion and a history of pain on chewing. Radiographs show widened periodontal ligament space and a periapical radiolucency. What is the most likely diagnosis?

  1. Irreversible pulpitis with symptomatic apical periodontitis Correct answer.
  2. Reversible pulpitis
  3. Dentinal hypersensitivity
  4. Normal pulp

Explanation

Pain on chewing with a widened PDL space and periapical radiolucency indicates inflammation extending beyond the pulp into the periapical tissues, consistent with irreversible pulpitis and symptomatic apical periodontitis. Reversible pulpitis and normal pulp do not produce periapical radiographic changes. Dentinal hypersensitivity is a short, sharp response to stimuli without periapical findings.

Question 18Dentistry

Which of the following is the most appropriate management for a mandibular fracture with displacement and malocclusion in a growing child?

  1. Immediate open reduction and internal fixation with plates
  2. Observation alone
  3. Extraction of involved teeth
  4. Closed reduction with maxillomandibular fixation or functional appliance Correct answer.

Explanation

In growing children, mandibular fractures are generally managed with closed reduction and fixation or functional appliances to protect developing tooth germs and growth centers. Open reduction with rigid fixation is reserved for severely displaced or unstable fractures. Observation alone is insufficient for displaced fractures with malocclusion.

Question 19Dentistry

Which of the following is the most common cause of tooth loss in adults in developed countries?

  1. Trauma
  2. Periodontal disease Correct answer.
  3. Developmental anomalies
  4. Dental caries

Explanation

Periodontal disease is the leading cause of tooth loss in adults, particularly after age 35, while caries remains a major cause in younger populations. Trauma and developmental anomalies account for a smaller proportion. Prevention and periodontal maintenance are therefore central to adult oral health.

Question 20Dentistry

A patient with a history of radiation therapy to the head and neck requires extraction of a mandibular molar. Which of the following is the most important consideration?

  1. Risk of osteoradionecrosis Correct answer.
  2. Extraction is contraindicated permanently
  3. Immediate implant placement
  4. Use of a local anesthetic without vasoconstrictor

Explanation

Radiation therapy causes hypovascular, hypocellular, and hypoxic tissue changes that predispose to osteoradionecrosis after extraction. Careful treatment planning, including timing relative to radiation and atraumatic technique, is essential. Extraction is not permanently contraindicated, but risk must be managed.

Question 21Dentistry

Which of the following is the most appropriate first step in managing a child with a suspected allergy to latex during a dental appointment?

  1. Remove latex products and manage the reaction according to severity Correct answer.
  2. Prescribe antibiotics
  3. Continue treatment with latex gloves
  4. Refer for extraction of all teeth

Explanation

The first step is to remove the offending latex products and manage the allergic reaction according to its severity, using a latex-free environment for future care. Continuing exposure risks anaphylaxis. Antibiotics and extraction are unrelated to allergy management.

Question 22Dentistry

Which of the following best describes the mechanism of action of fluoride in caries prevention?

  1. It promotes remineralization and inhibits demineralization of enamel Correct answer.
  2. It physically seals all pits and fissures
  3. It neutralizes all dietary acids permanently
  4. It kills all oral bacteria

Explanation

Fluoride enhances remineralization, forms fluorapatite, and inhibits demineralization of enamel, reducing caries susceptibility. It does not sterilize the oral cavity or permanently neutralize acids. Its effect is topical and requires ongoing exposure.

Question 23Dentistry

A patient presents with a painless, sessile, firm nodule on the buccal mucosa that has been present for years. Biopsy reveals a benign fibrous connective tissue proliferation. What is the most likely diagnosis?

  1. Fibroma Correct answer.
  2. Squamous cell carcinoma
  3. Hemangioma
  4. Pleomorphic adenoma

Explanation

A fibroma is a benign, painless, firm nodule of fibrous connective tissue often arising from chronic irritation. Squamous cell carcinoma is typically ulcerated and indurated, pleomorphic adenoma arises in salivary glands, and hemangioma is vascular and compressible.

Question 24Dentistry

Which of the following is the recommended treatment for a tooth with a horizontal root fracture in the middle third and a vital pulp?

  1. Repositioning and stabilization with a flexible splint Correct answer.
  2. Immediate root canal treatment
  3. Extraction
  4. Apicoectomy

Explanation

Horizontal mid-root fractures with a vital pulp are managed by repositioning the coronal fragment and stabilizing with a flexible splint to allow healing. Root canal treatment is indicated only if the pulp becomes necrotic. Extraction and apicoectomy are not first-line for this injury.

Question 25Dentistry

Which of the following is the most appropriate impression material for a precise crown preparation when dimensional stability and detail reproduction are required?

  1. Addition silicone (polyvinyl siloxane) Correct answer.
  2. Plaster
  3. Alginate
  4. Zinc oxide eugenol

Explanation

Addition silicone, or polyvinyl siloxane, offers excellent dimensional stability, detail reproduction, and elastic recovery, making it suitable for precise crown impressions. Alginate is dimensionally unstable, and zinc oxide eugenol and plaster are not used for this purpose.

Question 26Dentistry

A 45-year-old patient has a non-vital maxillary central incisor with a large periapical radiolucency. After chemomechanical preparation and calcium hydroxide dressing, which of the following best determines the appropriate time to obturate the canal?

  1. The patient reports no pain for at least 24 hours
  2. The working length has been reconfirmed with an apex locator
  3. The canal is dry and free of exudate with no persistent symptoms Correct answer.
  4. The periapical radiolucency has completely resolved radiographically

Explanation

Obturation should be delayed until the canal is dry, free of exudate and the tooth is asymptomatic, because residual infection at the time of filling compromises healing. Radiographic resolution of a periapical lesion lags behind clinical healing and is not a prerequisite for obturation. Absence of pain alone is insufficient if exudate persists.

Question 27Dentistry

Which local anesthetic property best explains why articaine provides effective pulpal anesthesia in mandibular molars more reliably than an equivalent volume of lidocaine?

  1. It contains a vasoconstrictor that is twice as potent as epinephrine
  2. It is formulated at a higher pH than lidocaine solutions
  3. It has a longer plasma half-life than other amide anesthetics
  4. It has a thiophene ring and an ester side chain that increase lipid solubility Correct answer.

Explanation

Articaine is unique among amide anesthetics in containing a thiophene ring and an ester linkage, which increases its lipid solubility and improves diffusion through bone. This enhanced penetration explains its higher success for mandibular infiltration and buccal infiltration. Its vasoconstrictor is epinephrine, the same as in lidocaine preparations.

Question 28Dentistry

A 9-year-old child has a grossly carious mandibular second primary molar with a necrotic pulp and a radiolucency extending into the furcation. The permanent successor is developing normally with adequate space. Which of the following is the most appropriate management?

  1. Pulpectomy with zinc oxide eugenol
  2. Pulpotomy with formocresol
  3. Extraction with space maintenance Correct answer.
  4. Indirect pulp capping

Explanation

A necrotic primary molar with furcation involvement has a poor prognosis, and the furcation is the usual path of infection in primary teeth. Extraction followed by a space maintainer preserves arch length for the developing successor. Vital pulp therapies are contraindicated once the pulp is necrotic.

Question 29Dentistry

Which of the following best describes the primary mechanism by which chlorhexidine mouthrinse reduces plaque formation?

  1. It dissolves existing calculus deposits on the tooth surface
  2. It binds to negatively charged bacterial cell surfaces and causes cytoplasmic leakage Correct answer.
  3. It inhibits bacterial adhesion by blocking salivary glycoprotein receptors
  4. It neutralizes acids produced by cariogenic bacteria

Explanation

Chlorhexidine is a cationic bisbiguanide that binds to negatively charged bacterial surfaces, disrupting the cell membrane and causing cytoplasmic leakage and bacterial death. It also has substantivity because it binds to oral tissues and is released gradually. It does not dissolve calculus or neutralize acids.

Question 30Dentistry

A patient has a Class II division 1 malocclusion with an increased overjet of 9 mm and a deep overbite. Which of the following is the most important immediate concern during the initial assessment?

  1. Temporomandibular joint clicking
  2. Gingival recession on the mandibular incisors
  3. Speech articulation difficulty
  4. Trauma risk to the maxillary incisors Correct answer.

Explanation

A large overjet predisposes the maxillary incisors to traumatic injury, particularly in children, and this risk is a key reason for early intervention. Gingival recession, joint symptoms and speech issues may coexist but are not the priority concern with this magnitude of overjet.

Question 31Dentistry

Which of the following is the most appropriate definitive treatment for a tooth with a horizontal mid-root fracture where the coronal fragment is displaced and the pulp is necrotic?

  1. Repositioning the coronal fragment and endodontic treatment of the coronal segment Correct answer.
  2. Extraction and implant placement
  3. Immediate apical surgery on the coronal fragment
  4. Splinting without endodontic treatment

Explanation

Mid-root horizontal fractures with a necrotic coronal pulp are managed by repositioning and stabilizing the coronal fragment, followed by endodontic treatment of the coronal segment. The apical fragment often retains a vital pulp and may not require treatment. Extraction is reserved for severely displaced or unrestorable fractures.

Question 32Dentistry

Which of the following is the most common odontogenic cyst of the jaws?

  1. Dentigerous cyst
  2. Odontogenic keratocyst
  3. Lateral periodontal cyst
  4. Radicular cyst Correct answer.

Explanation

The radicular cyst, also called a periapical cyst, arises from epithelial rests of Malassez in a periapical granuloma and is the most common odontogenic cyst. It is associated with a non-vital tooth. Dentigerous cysts are the second most common and are associated with an unerupted crown.

Question 33Dentistry

A patient with a severely worn dentition has lost occlusal vertical dimension. Which of the following is the most appropriate initial step in prosthetic rehabilitation?

  1. Extract all remaining posterior teeth
  2. Establish a trial vertical dimension using a removable appliance or provisional restorations Correct answer.
  3. Immediately cement definitive full-coverage cast restorations
  4. Perform a bilateral sagittal split osteotomy

Explanation

When vertical dimension must be increased, it should be tested with a removable overlay appliance or provisional restorations before definitive treatment. This allows assessment of patient tolerance, esthetics and phonetics. Definitive restorations should be placed only after the new dimension is validated.

Question 34Dentistry

Which of the following best explains why a bevel is placed on the facial margin of a metal-ceramic crown preparation?

  1. To improve the fit of the intaglio surface
  2. To increase the surface area for bonding and improve the metal-ceramic junction Correct answer.
  3. To reduce the amount of tooth reduction needed
  4. To allow the use of a glass ionomer cement

Explanation

A facial bevel on a metal-ceramic preparation provides a gradual transition from metal to porcelain and increases the area for the metal-ceramic bond. It also improves the esthetic blend of the margin. It does not reduce the need for axial reduction or affect cement choice.

Question 35Dentistry

Which of the following is the most reliable method for confirming the working length during root canal treatment?

  1. Paper point bleeding
  2. Electronic apex locator combined with a confirmatory radiograph Correct answer.
  3. Radiograph alone
  4. Tactile sensation of the apical constriction

Explanation

An electronic apex locator combined with a radiograph provides the most reliable working length determination, because the locator identifies the apical constriction while the radiograph confirms the position. Tactile sensation is unreliable, especially in curved or calcified canals. A radiograph alone has parallax and distortion limitations.

Question 36Dentistry

A 60-year-old patient on long-term warfarin therapy with an INR of 3.5 requires extraction of two mandibular molars. Which of the following is the most appropriate management?

  1. Stop warfarin for five days without medical consultation
  2. Proceed with extraction without modification
  3. Consult the physician and consider adjusting anticoagulation before extraction Correct answer.
  4. Prescribe tranexamic acid and extract without further assessment

Explanation

An INR of 3.5 is above the usual therapeutic range for most indications, and extraction carries a bleeding risk. The physician should be consulted to review anticoagulation and consider adjustment before surgery. Local hemostatic measures can be used as an adjunct, but they do not replace medical assessment.

Question 37Dentistry

Which of the following is the most appropriate first-line treatment for a patient with symptomatic trigeminal neuralgia affecting the mandibular division?

  1. Carbamazepine Correct answer.
  2. Ibuprofen
  3. Amoxicillin
  4. Prednisolone

Explanation

Carbamazepine is the first-line pharmacologic treatment for trigeminal neuralgia and is effective in most patients. Antibiotics, nonsteroidal anti-inflammatory drugs and corticosteroids do not treat the neuropathic mechanism. Referral for surgical options is considered when medication fails.

Question 38Dentistry

A patient requests replacement of a missing maxillary central incisor. Which of the following is the most important factor when deciding between an implant and a resin-bonded bridge?

  1. The patient's age alone
  2. Patient's preference for a particular shade
  3. Condition of the adjacent teeth and the alveolar bone volume Correct answer.
  4. The type of impression material used

Explanation

The decision between an implant and a resin-bonded bridge depends primarily on the health of the adjacent teeth and the volume and quality of alveolar bone. A resin-bonded bridge is favored when adjacent teeth are sound and bone is inadequate, while an implant is preferred when bone support is sufficient. Shade and impression material are not determining factors.

Question 39Dentistry

Which of the following best describes the primary purpose of a surgical stent in implant placement?

  1. To measure bone density
  2. To serve as a temporary prosthesis
  3. To guide the drill position and angulation according to the planned prosthesis Correct answer.
  4. To provide hemostasis during surgery

Explanation

A surgical stent transfers the planned implant position, angulation and depth from the diagnostic wax-up or digital plan to the surgical site. This helps place the implant in a prosthodontically driven position. It does not provide hemostasis, act as a prosthesis or measure bone density.

Question 40Dentistry

A patient has generalized aggressive periodontitis with rapid attachment loss and a family history of early tooth loss. Which of the following is the most important initial step in management?

  1. Referral for bone grafting
  2. Comprehensive periodontal assessment including probing depths and radiographs Correct answer.
  3. Immediate systemic antibiotic therapy
  4. Extraction of all teeth with probing depths over 5 mm

Explanation

Management begins with a comprehensive periodontal assessment to establish the extent and pattern of disease before any treatment decision. Systemic antibiotics may be used as an adjunct but are not the initial step. Extraction and grafting are considered only after assessment and initial therapy.

Question 41Dentistry

Which of the following is the most common cause of failure of a resin-bonded fixed partial denture?

  1. Pulpal necrosis of the abutments
  2. Gingival hyperplasia
  3. Fracture of the pontic
  4. Debonding of the retainer Correct answer.

Explanation

Debonding is the most frequent complication of resin-bonded fixed partial dentures, often related to inadequate enamel preparation or moisture contamination during cementation. Pontic fracture and abutment pulpal problems are less common. Gingival hyperplasia is not a typical cause of failure.

Question 42Dentistry

A patient reports a burning sensation on the tongue and buccal mucosa that is worse in the evening. Examination shows a depapillated, erythematous tongue. Which of the following is the most likely underlying cause?

  1. Oral candidiasis
  2. Geographic tongue
  3. Vitamin B12 deficiency Correct answer.
  4. Dental amalgam allergy

Explanation

A depapillated, erythematous tongue with burning that worsens through the day suggests nutritional deficiency, particularly vitamin B12, folate or iron. Burning mouth symptoms in deficiency states often intensify in the evening. Amalgam allergy, candidiasis and geographic tongue have different clinical presentations.

Question 43Dentistry

Which of the following is the most appropriate treatment for a localized chronic periodontal abscess with a probing depth of 7 mm and suppuration?

  1. Extraction of the tooth
  2. Gingivectomy
  3. Drainage and subgingival debridement Correct answer.
  4. Immediate systemic antibiotics alone

Explanation

A periodontal abscess is managed by establishing drainage and debriding the subgingival deposits and necrotic tissue. Systemic antibiotics are an adjunct and are not used alone. Surgery or extraction is reserved for lesions that do not respond or teeth with a hopeless prognosis.

Question 44Dentistry

A patient has a mandibular complete denture with a sore spot on the lingual slope of the residual ridge. Which of the following is the most appropriate first step?

  1. Relieve the entire lingual flange
  2. Inspect the denture with pressure-indicating paste and adjust the corresponding area Correct answer.
  3. Prescribe antibiotics
  4. Remake the denture

Explanation

Sore spots under a denture are identified by applying pressure-indicating paste to the denture and locating the area of premature contact. Selective adjustment of that area relieves the pressure. Indiscriminate relief or remaking the denture is unnecessary and may worsen retention.

Question 45Dentistry

A patient with a history of head and neck radiation therapy develops osteoradionecrosis of the mandible after extraction. Which of the following is the most important preventive measure before extraction in such patients?

  1. Hyperbaric oxygen therapy or careful atraumatic extraction with primary closure Correct answer.
  2. Routine use of a vasoconstrictor-containing local anesthetic
  3. Immediate placement of a dental implant
  4. Prescription of antibiotics alone

Explanation

Prevention of osteoradionecrosis focuses on atraumatic surgery, primary mucosal closure and, in selected cases, hyperbaric oxygen therapy. These measures improve healing in hypovascular, hypoxic irradiated bone. Implant placement and antibiotics alone do not prevent the condition.

Question 46Dentistry

Which of the following is the most appropriate management for a child with a suspected latex allergy during a dental appointment?

  1. Stop treatment, remove latex items and manage the reaction according to severity Correct answer.
  2. Continue treatment with latex gloves and monitor
  3. Apply a topical antihistamine and continue
  4. Increase the dose of local anesthetic

Explanation

When latex allergy is suspected, treatment should stop and all latex-containing items should be removed. The reaction is then managed according to severity, with epinephrine for anaphylaxis and antihistamines for mild reactions. Continuing exposure or using topical agents alone is unsafe.

Question 47Dentistry

Which of the following best explains why enamel is more resistant to caries than dentin at the same pH?

  1. Enamel contains more water and organic material
  2. Enamel has a higher density of dentinal tubules
  3. Enamel has a higher mineral content and lower carbonate substitution Correct answer.
  4. Enamel is more permeable to bacterial acids

Explanation

Enamel is highly mineralized with a lower proportion of carbonate and organic material, making it less soluble at a given pH than dentin. Dentin contains more organic matrix and water, which increases acid diffusion and demineralization. Permeability and tubule density are features of dentin, not enamel.

Question 48Dentistry

A patient presents with a firm, non-tender swelling of the parotid gland that has been present for months. Which of the following is the most appropriate initial diagnostic step?

  1. Radical neck dissection
  2. Immediate superficial parotidectomy
  3. Empirical antibiotic therapy
  4. Fine-needle aspiration cytology Correct answer.

Explanation

Fine-needle aspiration cytology is a minimally invasive initial test that helps distinguish neoplastic from non-neoplastic parotid swellings. Imaging such as ultrasound or MRI may complement it. Surgery and neck dissection are definitive treatments, not initial diagnostic steps.

Question 49Dentistry

Which of the following is the most appropriate treatment for a tooth with a horizontal root fracture in the middle third where both fragments are vital and the coronal fragment is minimally displaced?

  1. Reposition if needed and splint for 4 weeks Correct answer.
  2. Extract the coronal fragment
  3. Place a crown immediately
  4. Perform immediate root canal treatment of both fragments

Explanation

Vital mid-root fractures with minimal displacement are managed by repositioning if necessary and flexible splinting, typically for about four weeks. Vital pulp tissue is preserved and endodontic treatment is indicated only if the pulp becomes necrotic. Extraction and immediate crown placement are not appropriate.

Question 50Dentistry

A patient has a mandibular fracture with displacement and malocclusion. Which of the following is the most appropriate definitive management?

  1. Immediate extraction of all teeth in the fracture line
  2. Application of a pressure dressing
  3. Open reduction and internal fixation Correct answer.
  4. Soft diet and observation alone

Explanation

Displaced mandibular fractures with malocclusion generally require reduction and fixation, often with open reduction and internal fixation, to restore occlusion and stability. Observation alone is inadequate for displaced fractures. Extracting teeth and pressure dressings do not provide skeletal stabilization.