MDS Entrance Exam preparation SET 2

Q1

What is the total number of deciduous (primary) teeth in the normal primary dentition?

A

16

B

20

C

24

D

28

Q2

Which type of occlusal relationship is defined by a Class II Division 1 malocclusion?

A

Upper incisors proclined and positioned labial to the lower incisors

B

Upper incisors retroclined and positioned palatal to the lower incisors

C

Upper molars mesiated relative to lower molars

D

Lower molars mesiated relative to upper molars

Q3

At what gestational week do the palatine shelves elevate from vertical to horizontal position?

A

6th week

B

7th week

C

8th week

D

9th week

Q4

Which of the following best describes the composition of the temporomandibular joint capsule?

A

Fibrous connective tissue reinforced laterally, lined by synovial membrane

B

Dense cartilage covering the entire joint surface

C

Elastic ligamentous tissue with no synovial lining

D

Muscular sheath formed by the masseter and temporalis

Q5

A 5-year-old child develops a painless, firm, submandibular swelling with a draining sinus tract that expels sulfur granules. The most likely diagnosis is:

A

Actinomycosis

B

Noma

C

Tuberculous lymphadenitis

D

Chronic suppurative parotitis

Q6

A patient with oral submucous fibrosis presents with limited mouth opening. Which surgical procedure is most appropriate to improve oral function?

A

Coronoidectomy with release of fibrous bands

B

Partial glossectomy

C

Laser ablation of the lesion

D

Excisional biopsy of the fibrous tissue

Q7

The 'caries balance' concept in dental caries involves the dynamic interaction between:

A

Fluoride and calcium

B

Pathogenic bacteria and host immunity

C

Enamel and dentin

D

Saliva and plaque

Q8

Which statement about paracetamol is FALSE?

A

It has analgesic and antipyretic action

B

It inhibits COX-3 in the CNS

C

It is safe in patients with peptic ulcer

D

It has strong anti-inflammatory action

Q9

Which medication is indicated for a patient with chest pain suggestive of myocardial ischemia in a dental office?

A

nitroglycerin sublingual 0.4 mg

B

aspirin 325 mg chewable

C

morphine 4 mg intravenously

D

propranolol 10 mg oral

Q10

The setting reaction of alginate impression material involves the formation of which gel?

A

Calcium alginate gel

B

Sodium alginate gel

C

Potassium alginate gel

D

Magnesium alginate gel

Q11

In dental ceramics, 'crazing' refers to:

A

The process of adding a glaze

B

The formation of a network of fine surface cracks

C

The fusion of ceramic powder

D

The chemical etching of the surface

Q12

Which of the following is NOT a feature of resistance form in an amalgam preparation?

A

Flat pulpal floor

B

Rounded internal line angles

C

Converging walls

D

Adequate thickness of restorative material

Q13

In a maxillary complete denture, the posterior palatal seal area is located:

A

At the junction of hard and soft palate

B

2 mm anterior to the fovea palatina

C

Within the vibrating line

D

5 mm posterior to the hamular notch

Q14

The primary reason for opening a Class II proximal box is to?

A

increase retention

B

ease of caries removal

C

reduce pulp exposure

D

simplify finishing

Q15

In a tooth with a calcified canal, what is the recommended first step to locate the canal?

A

Use of a dental operating microscope with ultrasonic tips

B

Blind probing with a #8 K-file

C

Immediate use of a rotary NiTi file

D

Performing a surgical flap to expose the pulp chamber

Q16

Which of the following is the most common sequelae following luxation injury of a permanent incisor?

A

Internal resorption

B

External inflammatory resorption

C

Ankylosis

D

Pulp calcification

Q17

Which of the following is NOT part of the Basic Periodontal Examination (BPE)?

A

Probing depth

B

Clinical attachment level

C

Plaque index

D

Bleeding on probing

Q18

Which of the following is a key component of the WHO classification of periodontal diseases?

A

Tooth mobility

B

Clinical attachment loss

C

Alveolar bone density

D

Plaque index

Q19

Surgical exposure and orthodontic traction of an impacted maxillary canine is indicated when:

A

The canine is positioned palatally with sufficient space available

B

The canine is fused to the nasal floor

C

The patient is over 30 years old

D

The canine shows resorption of the lateral incisor

Q20

Which anatomical structures are typically involved in a Le Fort II fracture?

A

Nasal bridge, orbital floors, and maxillary sinuses

B

Only the maxillary alveolar process

C

Zygomatic arch and orbital rim

D

Mandibular condyle and body

Q21

In a patient with acute postoperative trismus after mandibular surgery, the best pharmacologic agent to relieve pain and reduce muscle spasm is:

A

Oral ibuprofen.

B

Oral clonazepam.

C

Intramuscular methylprednisolone.

D

Intramuscular lidocaine injection.

Q22

Which technique is preferred for tooth arrangement in a maxillary complete denture?

A

Centric relation alignment of tooth arrangement

B

Maximum overlap of all teeth

C

Placement of teeth on a straight line

D

Use of alloy framework

Q23

What is the primary purpose of 'taper' in a crown preparation?

A

To increase the retention of the crown

B

To facilitate a path of insertion

C

To increase the strength of the cement

D

To improve the marginal fit

Q24

Which of the following is a contraindication for taking a panoramic radiograph in a pregnant patient?

A

First trimester exposure

B

Second trimester exposure

C

Third trimester exposure

D

All trimesters are contraindicated

Q25

In pediatric dentistry, which medication is most strongly associated with xerostomia and consequently increased caries risk?

A

Amitriptyline

B

Ibuprofen

C

Amoxicillin

D

Paracetamol

Q26

Which of the following is the primary advantage of using mineral trioxide aggregate (MTA) over formocresol for primary tooth pulpotomy?

A

Lower cost

B

Faster setting time

C

Biocompatibility and reduced toxicity

D

Better radiopacity

Q27

Which of the following is a primary indication for early orthodontic treatment in a 7-year-old?

A

Class II division 2 malocclusion

B

Missing first permanent molars

C

Protrusive incisors requiring space maintenance

D

Angle's Class III malocclusion

Q28

A patient undergoing chemotherapy for acute lymphoblastic leukemia presents for a routine dental cleaning. What is the most appropriate timing for the cleaning?

A

During the neutropenic phase (ANC <500 cells/µL)

B

One week after the last chemotherapy session when ANC >1500 cells/µL

C

Immediately before the next chemotherapy cycle

D

Only after hematopoietic stem cell transplantation

Q29

A COPD patient suddenly becomes severely dyspneic with wheeze during a dental procedure. What is the best immediate therapy?

A

Give subcutaneous epinephrine

B

Give nebulized ipratropium and albuterol

C

Give IV steroids

D

Give oral theophylline

Q30

According to Nepal's oral health policy, which of the following is a recommended strategy to increase fluoridation of drinking water?

A

Importing bottled fluoride water

B

Installing household-level fluoridation devices

C

Central water supply fluoridation with sodium fluoride

D

Adding fluoride tablets to sugar refineries

Q31

Under the Dentists Act, 2048 (1991) of Nepal, which authority is responsible for the registration and regulation of dental practitioners?

A

Ministry of Health and Population

B

Nepal Medical Council

C

Nepal Dental Council

D

Health Professional Council

Q32

In the cervical third of a mature molar, enamel rods are arranged in a pattern characterized by?

A

Decussating interwoven rods

B

Uniform parallel rods

C

Random orientation

D

Tortuous spirals

Q33

Which of the following is a key consideration when preparing a class I restoration on a molar to avoid postoperative sensitivity?

A

Preserve at least 1.5 mm enamel

B

Avoid cutting into dentin

C

Use a flat outline

D

Include a proximal box

Q34

According to IADT guidelines, what antibiotic regimen is advised for replantation of an avulsed tooth in a healthy patient?

A

Amoxicillin 2 g orally as a single dose

B

Clindamycin 600 mg IV every 8 h for 5 days

C

Penicillin V 500 mg orally every 6 h for 7 days

D

No antibiotics are required

Q35

Bleeding on probing (BOP) is primarily indicative of which condition?

A

Stable periodontal status

B

Active inflammatory disease

C

Previous orthodontic treatment

D

Adequate oral hygiene

Q36

Which liver condition is most frequently associated with periodontal disease due to shared inflammatory pathways?

A

alcoholic cirrhosis

B

hepatitis C

C

non-alcoholic fatty liver disease

D

hepatitis B

Q37

Which force is applied during the use of a dental elevator to 'luxate' a tooth?

A

Pure traction

B

Rotational and wedging force

C

Vertical compression

D

Centripetal force

Q38

Which of the following is a relative contraindication to maxillomandibular fixation in mandibular fracture management?

A

Severe periodontitis

B

Mild nasal congestion

C

Patient age >60 years

D

History of seasonal allergies

Q39

Which of the following statements about immediate loading of dental implants is correct?

A

Immediate loading is contraindicated in the posterior mandible due to poor bone quality.

B

Primary implant stability of at least 35 Ncm is required for successful immediate loading.

C

Immediate loading can only be used with mini-implants.

D

Immediate loading eliminates the need for a healing abutment.

Q40

Which non-pharmacologic technique is specifically designed to allow the dentist to retreat the child from a fearful situation?

A

Pause-and-return method

B

Escape-space technique

C

Stop-sign approach

D

Reset-and-restart protocol

Q41

In a dental operatory that frequently treats immunocompromised patients, which hand-hygiene method provides the quickest and most effective reduction of transient flora before patient contact?

A

70% isopropyl alcohol hand rub

B

0.5% chlorhexidine gluconate hand wash

C

Plain soap and water

D

Povidone-iodine scrub

Q42

Which of the following is NOT a typical component of Nepal's community-based school dental health outreach?

A

Oral hygiene demonstration

B

Provision of free fluoride tablets

C

Mandatory extraction of all carious teeth

D

Referral to local dental clinics

Q43

In the ICDAS system, which code denotes an active enamel carious lesion that is distinctly visible without cavitation?

A

Code 1 (non-carious)

B

Code 2 (slight demineralization)

C

Code 3 (obvious enamel lesion)

D

Code 4 (dentin lesion)

Q44

The optimal coefficient of thermal expansion (CTE) mismatch between a metal substructure and the overlying porcelain in a metal-ceramic crown should be:

A

Porcelain CTE 0.5–1.0 ×10⁻⁶ /°C higher than metal

B

Porcelain CTE equal to metal

C

Porcelain CTE 0.5–1.0 ×10⁻⁶ /°C lower than metal

D

Porcelain CTE 2–3 ×10⁻⁶ /°C higher than metal

Q45

Which condition is a contraindication for using calcium silicate-based cement in regenerative endodontics?

A

blood contamination during placement

B

high moisture environment

C

presence of tooth decay

D

existing metallic restoration

Q46

According to the principles of conservative operative dentistry, the 'minimum depth' for an amalgam restoration is generally recommended to be:

A

0.5 mm

B

1.0 mm

C

1.5 mm

D

2.5 mm

Q47

During orthognathic surgery, a sudden bradycardia of 40 bpm with hypotension occurs after manipulation of the maxilla. What is the most likely cause?

A

Hypovolemia

B

Trigeminocardiac reflex

C

Anaphylaxis

D

Myocardial infarction

Q48

Which of the following is the primary reason for utilizing a 'Selective Pressure' technique in final impressions?

A

To maximize the use of all available ridge area

B

To avoid overloading displaceable tissues

C

To eliminate the need for border molding

D

To increase the thickness of the denture base

Q49

When performing a pulpectomy in a primary tooth, why is it critical to avoid over-instrumenting the apical foramen?

A

To prevent permanent tooth eruption delays

B

To avoid damaging the permanent tooth bud

C

To prevent the formation of a periapical cyst

D

To maintain the integrity of the alveolar bone

Q50

Which of the following is the most critical consideration when treating a patient who has a cardiac pacemaker?

A

Avoid all local anesthetics with epinephrine

B

Avoid the use of ultrasonic scalers in the immediate vicinity of the device

C

Avoid using any form of sedation

D

Avoid all dental X-rays

Q51

In Nepal, if a dentist discovers that a colleague is practicing beyond the scope of permitted dental procedures, the dentist should:

A

Ignore it to avoid conflict

B

Report the matter to the Nepal Dental Council disciplinary committee

C

Confront the colleague privately without further action

D

Assist the colleague in performing the procedures

Q52

Which bone forms the anterosuperior border of the mandibular condyle articulation with the temporal bone?

A

Frontal

B

Maxillary

C

Temporal

D

Occipital

Q53

A patient with a known history of diabetes mellitus loses consciousness. If the blood glucose monitor is unavailable, the safest emergency assumption is:

A

Assume hyperglycemia and give insulin

B

Assume hypoglycemia and give glucose/glucagon

C

Assume a stroke and give aspirin

D

Assume syncope and give nothing

Q54

Which of the following is a potential cause of 'voids' in a gypsum cast?

A

Using too little water

B

Insufficient vibration during pouring

C

Over-mixing the stone

D

Using a vacuum mixer

Q55

The ideal apical extent of root canal obturation relative to the radiographic apex is:

A

0-0.5 mm short

B

0.5-1 mm short

C

1-2 mm short

D

2-3 mm short

Q56

Which of the following describes the root morphology of the permanent maxillary first premolar?

A

Always single rooted

B

Usually two roots (buccal and lingual)

C

Three roots (mesiobuccal, distobuccal, palatal)

D

Two roots (mesial and distal)

Q57

According to the WHO tumor-node-metastasis staging system, which combination defines a T2 oral carcinoma?

A

≤2 cm in greatest dimension and depth of invasion ≤5 mm

B

>2 cm but ≤4 cm or depth of invasion >5 mm but ≤15 mm

C

Any tumor >4 cm in size

D

Presence of regional nodal metastasis

Q58

A patient on chronic β-blocker therapy develops bronchospasm after receiving a lidocaine-epinephrine solution. Which drug is most effective in reversing the bronchospasm?

A

Atropine

B

Ipratropium bromide

C

Inhaled short-acting β2-agonist

D

Sodium bicarbonate

Q59

A 50-year-old patient complains of intermittent mandibular pain. An intraoral periapical radiograph shows a well-defined radiolucency at the apex of the lower left central incisor with a thick, corticated radiopaque border. The most likely diagnosis is:

A

Radicular cyst

B

Condensing osteitis

C

Ameloblastoma

D

Central giant cell granuloma

Q60

In a community water supply with naturally occurring fluoride at 0.7 ppm, what is the optimal adjustment strategy to achieve ideal fluoride levels for caries prevention?

A

No adjustment needed as 0.7 ppm is optimal

B

Add fluoride salts to increase to 1.0 ppm

C

Dilute water to reduce to 0.3 ppm

D

Stop fluoridation efforts entirely

Q61

Which of the following best describes the histological composition of the attached gingiva?

A

Keratinized stratified squamous epithelium with a thin lamina propria

B

Non-keratinized stratified squamous epithelium with a thick lamina propria

C

Simple columnar epithelium with lymphoid aggregates

D

Pseudostratified ciliated epithelium with goblet cells

Q62

Which of the following statements about clinical attachment level (CAL) is correct?

A

CAL = Probing depth – Gingival recession

B

CAL = Probing depth + Gingival recession

C

CAL is measured from the cementoenamel junction to the base of the pocket

D

CAL cannot be calculated when gingival margin is coronal to the CEJ

Q63

In the management of traumatic dental injuries, which of the following is the most common long-term sequelae following luxation injury of a permanent incisor?

A

Pulp necrosis

B

Fibrosis

C

Chronic periodontitis

D

Delayed eruption

Q64

A Class III malocclusion in a 7-year-old child due to maxillary deficiency is BEST managed initially with:

A

Chin cup therapy

B

Reverse pull headgear (facemask)

C

Functional appliance for mandibular retrusion

D

Orthognathic surgery

Q65

Which error MOST commonly causes soreness at the crest of the residual ridge in both arches?

A

Occlusal prematurities

B

Underextended denture borders

C

Inadequate relief over frenum

D

Thin denture base

Q66

An 8-year-old child reports immediately after trauma with a maxillary central incisor displaced palatally. The tooth is tender to percussion, shows increased mobility, but is not completely out of the socket. Radiograph shows no root fracture. The MOST appropriate immediate management is:

A

Observation only and review after 2 weeks

B

Reposition the tooth and apply a flexible splint

C

Extract the tooth to prevent damage to successor

D

Initiate root canal treatment immediately

Q67

The most effective strategy for reducing sugar consumption among school children in Nepal is

A

Health education on diet

B

Tax on sugary drinks

C

School canteen policy limiting sugary foods

D

Parental involvement

Q68

The most appropriate treatment for malignant ameloblastoma is:

A

Enucleation

B

Curettage

C

Marginal resection

D

Radical resection with clear margins

Q69

The most common radiographic finding indicating pulpal necrosis after a traumatic crown fracture is?

A

Loss of lamina dura

B

Gum swelling

C

Periapical radiolucency

D

Cementoenamel junction defect

Q70

The 'two-way relationship' between periodontitis and diabetes mellitus implies that:

A

Periodontitis causes diabetes and diabetes causes periodontitis

B

Only diabetes influences the severity of periodontitis

C

Diabetes increases periodontal destruction, and periodontitis impairs glycemic control

D

Periodontal therapy is only effective if diabetes is fully cured

Q71

Neural-crest cells contribute to all of the following developing dental structures EXCEPT:

A

Dentin

B

Pulp tissue

C

Enamel organ

D

Periodontal ligament

Q72

Which property of a local anesthetic most influences its potency?

A

pKa

B

Molecular weight

C

Lipid solubility

D

Protein binding

Q73

When evaluating potential nanotoxicity of a nanofilled dental composite, which assay is most sensitive for detecting DNA strand breaks caused by nano-sized particles?

A

MTT cell viability assay

B

hemolysis test

C

comet assay

D

ELISA for IL-6

Q74

During surgical removal of a mandibular third molar, the most effective adjunct for immediate hemostasis is?

A

Electrocautery

B

Gauze packing with pressure

C

Ice application

D

Antibiotic mouthwash

Q75

A tripod fracture of the zygomaticomaxillary complex typically involves fracture of which three bony components?

A

Zygomatic bone, orbital plate, and frontal process

B

Zygomatic bone, maxilla, and nasal bone

C

Temporal bone, zygomatic bone, and mandible

D

Orbital plate, lacrimal bone, and palatine bone

Q76

The magnification factor in a panoramic radiograph is approximately:

A

1.1

B

1.5

C

2.0

D

0.8

Q77

Downward and forward rotation of the mandible during growth results in which facial characteristic?

A

Increased lower facial height

B

Decreased lower facial height

C

Increased overjet

D

Decreased overbite

Q78

Which organism is most frequently isolated in denture-associated stomatitis?

A

Candida albicans

B

Staphylococcus epidermidis

C

Pseudomonas aeruginosa

D

Lactobacillus casei

Q79

Which statement correctly describes the effect of increasing palladium content in a dental alloy?

A

increases hardness

B

improves corrosion resistance

C

reduces melting point

D

increases thermal expansion coefficient

Q80

What is the main advantage of using a preheated composite in an anterior restoration?

A

Increased flow

B

Reduced polymerization shrinkage

C

Improved marginal adaptation

D

Higher translucency

Q81

In a Class I cavity on a first permanent molar, which preparation design is considered the most conservative while still providing adequate retention?

A

Box with slightly tapered walls and no cavosurface bevel

B

Box with undercuts and no taper

C

Box with no walls and only enamel margins

D

Box with deep axial walls and no floor

Q82

Which of the following is the most appropriate management for a patient who develops a severe 'Thunderclap' headache and focal neurological deficits immediately following a maxillofacial procedure involving high-pressure instrumentation?

A

Administration of high-dose analgesics

B

Immediate referral for CT Angiography/Neurological emergency

C

Observation for 24 hours

D

Administration of intravenous fluids

Q83

Which imaging modality is most appropriate for diagnosing root fractures that involve both buccal and lingual cortical plates?

A

CBCT

B

Panoramic radiograph

C

Periapical radiograph

D

Conventional CT

Q84

According to the Dentists Act, 2048 (1991) of Nepal, which of the following actions can lead to suspension or cancellation of a dentist's registration?

A

failure to renew annual registration fee

B

advertising dental services with comparative claims

C

providing treatment without adequate infection control

D

all of the above

Q85

Which cranial nerve carries the pre-ganglionic parasympathetic fibers that synapse in the otic ganglion before reaching the parotid gland?

A

Glossopharyngeal nerve

B

Facial nerve

C

Vagus nerve

D

Trigeminal nerve

Q86

Which oral condition is NOT recognized as an oral potentially malignant disorder by WHO?

A

Oral lichen planus

B

Oral submucous fibrosis

C

Oral candidiasis

D

Erythroplakia

Q87

Which obturation technique provides the highest degree of lateral condensation of gutta-percha during the initial phase of treatment?

A

Sequential cold lateral condensation

B

Warm vertical compaction

C

Direct dry vertical compaction

D

High-speed thermal compaction

Q88

During a re-evaluation 6 weeks after non-surgical therapy, a site shows probing depth reduction from 6 mm to 4 mm, CAL unchanged, and no bleeding on probing. This outcome most likely reflects:

A

True attachment gain

B

Gingival recession with pocket depth reduction

C

Resolution of edema with no change in attachment level

D

Probing error

Q89

Which deciduous tooth is typically the first to be exfoliated in a normal primary dentition sequence?

A

Mandibular central incissor

B

Maxillary central incisor

C

Second primary premolar

D

Third primary molar

Q90

Which complement pathway is primarily activated during Candida albicans infection of the oral mucosa?

A

Classical

B

Lectin

C

Alternative

D

Terminal

Q91

Which of the following is NOT a prognostic factor for the success of replantation of an avulsed tooth?

A

Extra-oral dry time

B

Storage medium

C

Stage of root development

D

Patient's blood type

Q92

The 'Curve of Wilson' is best described as which of the following anatomical features?

A

Anteroposterior curvature of the occlusal surfaces

B

Mediolateral curvature of the occlusal surfaces

C

Vertical alignment of the canine eminence

D

The angle formed by the long axis of the maxillary incisors

Q93

What is the maximum permissible fluoride concentration in natural spring water used for drinking in Nepal's water-quality regulations?

A

0.5 mg/L

B

0.8 mg/L

C

1.0 mg/L

D

1.5 mg/L

Q94

In stepwise (partial) caries removal for a deep lesion in a primary molar, what is the usual interval before the second excavation?

A

1 week

B

1 month

C

3 months

D

6 months

Q95

Which concentration of fluoride in a varnish formulation has been shown to be most effective for caries prevention in high-risk patients?

A

0.5% NaF

B

2.5% NaF

C

5% NaF

D

10% NaF

Q96

Which factor is considered the most influential for the long-term success of root canal therapy in preventing reinfection?

A

Type of obturation technique

B

Quality of coronal restoration

C

Number of visits

D

Use of antibiotics

Q97

Which assay is recommended by ISO 10993-5 for assessing the cytotoxic potential of extracts from a dental material?

A

MTT assay

B

Ames bacterial reverse mutation test

C

Brine shrimp lethality test

D

DPPH radical scavenging assay

Q98

The factor that most strongly determines the retention of a resin-bonded bridge is:

A

Thickness of the composite

B

Bonding area

C

Shade of the composite

D

Type of cement

Q99

Which of the following is the most common etiologic factor leading to internal resorption in a previously unrestored tooth?

A

Pulp necrosis due to deep caries

B

Excessive instrumentation during root canal therapy

C

Trauma leading to loss of pulp vitality

D

Placement of a crown

Q100

To reduce the risk of dry socket after mandibular third molar extraction, which postoperative instruction is most appropriate?

A

Rinse vigorously with warm saline starting 2 hours post-op

B

Avoid smoking and using straws for at least 48 hours

C

Consume hot liquids immediately after surgery

D

Keep the gauze pack in place for 24 hours continuously

Q101

Which exposure modification will most effectively reduce patient dose while preserving diagnostic image quality in intraoral periapical radiography of an adult patient?

A

Decrease kVp by 15% and increase mAs proportionally

B

Increase kVp by 15% and reduce mAs by 50%

C

Reduce exposure time by 30% while keeping kVp constant

D

Use a higher speed film (or sensor) with the same exposure settings

Q102

Which method is most appropriate for assessing oral hygiene status of schoolchildren during a field survey?

A

Plaque Index

B

Simplified Oral Hygiene Index

C

Periodontal probing depth measurement

D

Radiographic examination

Q103

Which of the following vitamins, when deficient, leads to impaired collagen synthesis and causes bleeding gums and periodontal ligament breakdown?

A

Vitamin A

B

Vitamin C

C

Vitamin D

D

Vitamin K

Q104

A 30-year-old patient has a central giant cell granuloma of the mandible that has perforated the cortical plate. What is the most appropriate surgical treatment?

A

Segmental mandibulectomy

B

Enucleation with curettage

C

Marginal mandibulectomy

D

Adjunctive steroid injection

Q105

A 55-year-old male with a history of betel quid chewing presents with a plaque on the lower lip that appears leathery and fibrotic. The plaque is painless and increases in size over time. Which diagnosis is most likely?

A

Oral submucous fibrosis

B

Actinic cheilitis

C

Oral lichen planus

D

Scleroderma of the lip

Q106

According to conservative operative principles, what is the generally recommended minimum depth for an amalgam restoration measured from the enamel surface?

A

0.5 mm

B

1.0 mm

C

1.5 mm

D

2.0 mm

Q107

Which of the following is considered the most effective method to reduce polymerization shrinkage stress in large composite increments?

A

Use of a flowable liner beneath the composite

B

Incremental layering of 2 mm each

C

Application of a desensitizer before placement

D

Curing with a halogen light instead of LED

Q108

Which of the following local antimicrobials is most commonly placed in a periodontal pocket immediately after scaling and root planing to enhance bacterial reduction?

A

Chlorhexidine gluconate 0.12% mouth rinse

B

Tetracycline fibers

C

Metronidazole tablets

D

Amoxicillin syrup

Q109

Which of the following structures develops from the second pharyngeal arch?

A

Stapes

B

Glossopharyngeal nerve

C

Vagus nerve

D

Facial nerve

Q110

According to WHO Oral Health Surveys – Basic Methods, the recommended age groups for assessing dental caries in children are:

A

5, 12, and 15 years

B

6, 12, and 18 years

C

3, 6, and 9 years

D

2, 5, and 8 years

Q111

A 32-year-old male exhibits a well-defined radiolucency in the posterior mandible with scalloped margins extending between the roots of vital teeth. Histology shows a thin fibrous wall without epithelial lining. Which diagnosis fits best?

A

Traumatic bone cyst

B

Odontogenic keratocyst

C

Radicular cyst

D

Calcifying odontogenic cyst

Q112

A 55-year-old patient with chronic kidney disease stage 3 (CrCl 45 mL/min) requires postoperative analgesia after a third molar extraction. Which analgesic is safest?

A

Diclofenac

B

Acetaminophen

C

Ibuprofen

D

Ketorolac

Q113

When epinephrine is contraindicated because the patient is on β-blockers, which drug can be administered intramuscularly to treat the anaphylactic reaction?

A

Glucagon 1 mg IM

B

Diphenhydramine 50 mg IM

C

Hydrocortisone 100 mg IM

D

Methylprednisolone 125 mg IM

Q114

Which of the following is the most appropriate antimicrobial therapy for a patient diagnosed with a deep neck space infection (e.g., Parapharyngeal abscess) suspected to be polymicrobial?

A

Amoxicillin monotherapy

B

Clindamycin or Ampicillin-Sulbactam

C

Nystatin suspension

D

Acyclovir

Q115

Which of the following is the most critical factor in achieving a successful posterior palatal seal (PPS) in a maxillary complete denture?

A

Use of high-viscosity silicone

B

Compression of the soft tissues in the post-dam area

C

Extension of the denture base into the fovea palatinae

D

Application of cold-cure acrylic resin

Q116

Which artery is the primary blood supply to the submandibular gland?

A

Facial artery

B

Lingual artery

C

Maxillary artery

D

External carotid artery directly

Q117

A patient on chronic NSAID therapy is scheduled for root canal treatment. Which precaution is most important before proceeding?

A

Check liver enzyme levels

B

Assess renal function and urine output

C

Review platelet count

D

Monitor blood pressure

Q118

Which adjunctive pharmacologic agent is indicated for patients with periodontitis who are at high risk of attachment loss due to diabetes mellitus?

A

Chlorhexidine mouthwash

B

Systemic doxycycline 500 mg twice daily

C

Subantimicrobial-dose doxycycline 20 mg twice daily

D

Metronidazole 250 mg twice daily

Q119

During nitrous-oxide/oxygen sedation a patient becomes cyanotic and the pulse-oximeter reads 82 %. What is the immediate action?

A

Increase the nitrous-oxide concentration

B

Give 0.3 mg epinephrine intramuscularly

C

Stop nitrous-oxide and administer 100 % oxygen

D

Give 15 g oral glucose

Q120

Which of the following findings is least likely to be present in an acute apical abscess?

A

Severe spontaneous toothache

B

Facial swelling with pus formation

C

Localized gingival bleeding without pain

D

Fever and malaise

Q121

The most significant factor influencing the timing of eruption of the permanent maxillary second premolar is:

A

Genetic control

B

Nutritional status

C

Local oral hygiene

D

Systemic disease

Q122

When fluoride is applied to an acid-etched enamel surface, which compound forms and temporarily acts as a reservoir of fluoride ions?

A

Calcium fluoride

B

Hydroxyapatite

C

Fluorapatite

D

Sodium fluoride crystals

Q123

Which ligament connects the mandible to the styloid process of the temporal bone?

A

Stylomandibular ligament

B

Sphenomandibular ligament

C

Temporomandibular ligament

D

Ligamentum arteriosum

Q124

Which of the following describes the 'apical stop' or 'apical seat' in endodontic preparation?

A

The radiographic apex of the root

B

The point where the canal narrows significantly

C

A small ledge created at the apical constriction

D

A slight enlargement of the canal at the apical constriction

Q125

What fluoride concentration in toothpaste is recommended for adults by Nepal's national oral health guidelines?

A

500 ppm

B

1000 ppm

C

1500 ppm

D

2000 ppm

Q126

When selecting a gypsum product for a master cast of a removable partial denture framework, the most suitable choice is:

A

Type I impression plaster

B

Type II dental plaster

C

Type III dental stone

D

Type IV die stone

Q127

An advertisement promises a 'miracle cure' for gum disease on television. This violates which ethical principle?

A

Beneficence

B

Justice

C

Honesty

D

Confidentiality

Q128

A "conservation cavity" in a posterior tooth aims to preserve:

A

50% of original tooth structure

B

70% of original tooth structure

C

90% of original tooth structure

D

100% of original tooth structure

Q129

A new high-strength glass-ionomer cement shows no cytotoxicity in primary human gingival fibroblast culture. Which property of this material most likely contributes to this biocompatibility?

A

Acid-base setting reaction

B

Presence of fluoride

C

High phosphate content

D

Low solubility

Q130

Which of the following is the primary purpose of the 'proximal box' in a Class II cavity design?

A

To provide a bevel for bonding

B

To remove caries from the proximal surface and provide a stable base

C

To increase the pulpal depth

D

To create a mechanical lock with the enamel

Q131

Which of the following is NOT a common symptom of temporomandibular joint internal derangement?

A

pain at rest

B

clicking on opening

C

morning stiffness

D

swelling of parotid gland

Q132

Why is cone-beam CT generally unable to reliably detect bone-marrow edema?

A

Low soft-tissue contrast compared with conventional CT or MRI

B

High spatial resolution that masks subtle changes

C

Use of high kilovoltage (kV) beams

D

Relatively large voxel size

Q133

What is the recommended disposal method for sharps used on a patient with known hepatitis C in a dental clinic?

A

Autoclave before disposal

B

Place in puncture-resistant container and incinerate

C

Place in standard trash bag

D

Soak in bleach then discard

Q134

Which of the following is the most likely periodontal complication observed in patients receiving long-term corticosteroid therapy for systemic inflammatory diseases?

A

Rapidly resolving gingival inflammation

B

Increased susceptibility to opportunistic periodontal infections

C

Complete cessation of alveolar bone loss

D

Spontaneous gingival recession

Q135

In the context of Nepal's community dentistry outreach, which of the following is considered a barrier to accessing school dental services in mountainous regions?

A

Lack of dental manpower

B

High cost of treatment

C

Geographical inaccessibility

D

Low awareness of oral health

Q136

Which of the following is a result of the failure of the 'vestibular lamina' to rupture?

A

Cleft lip

B

Gingival cysts of the newborn

C

Dental lamina cysts

D

Ameloblastoma

Q137

Which of the following is the primary cause of 'white line' margins observed after the placement of a composite restoration?

A

Incomplete polymerization of the resin

B

Excessive fluoride release from the GIC liner

C

Over-etching of the enamel or failure to remove the smear layer

D

Use of a low-intensity curing light

Q138

A complete denture patient complains of soreness over the mylohyoid ridge after two weeks of use. Which clinical finding most likely explains this symptom?

A

Insufficient posterior flange extension

B

Over-extension of the mandibular lingual flange into the mylohyoid line

C

Under-extension of the maxillary posterior palatal seal

D

Improper occlusal vertical dimension

Q139

In a patient scheduled for a dental extraction who is on warfarin with an INR of 3.5, what is the recommended management?

A

Continue warfarin without change

B

Stop warfarin 3 days before extraction and repeat INR

C

Hold warfarin for 5 days before extraction

D

No change needed, proceed as planned

Q140

In histologic evaluation of an oral potentially malignant lesion, which cytologic abnormality is most characteristic of oral epithelial dysplasia on a brush biopsy?

A

Hyperchromatic nuclei with nuclear membrane irregularities

B

Abundant cytoplasmic glycogen

C

Multinucleated giant cells

D

Keratin pearls

Q141

According to Scott's growth analysis, the peak of mandibular growth velocity occurs most frequently in children of which age range?

A

10-11 years

B

12-13 years

C

14-15 years

D

16-17 years

Q142

Which radiographic feature best helps differentiate a Stafne bone defect from a cystic lesion of the mandible?

A

Location below the mandibular canal in the posterior mandible

B

Expansion of the buccal cortical plate

C

Scalloped margins between roots

D

Association with an impacted tooth

Q143

A patient is prescribed a course of Clindamycin for a dental abscess. Which of the following gastrointestinal complications is most specifically associated with this drug?

A

Acute pancreatitis

B

Pseudomembranous colitis

C

Drug-induced gastritis

D

Hepatic steatosis

Q144

The primary purpose of a periosteal releasing incision during flap surgery is to:

A

Increase flap thickness

B

Achieve primary closure without tension

C

Expose the alveolar bone

D

Remove the papilla

Q145

A patient develops severe trismus and dysphagia following an extraction of the mandibular third molar. On examination, there is swelling in the pterygomandibular space. Which muscle is primarily responsible for the restricted jaw opening?

A

Masseter

B

Temporalis

C

Medial pterygoid

D

Lateral pterygoid

Q146

In a primary molar with extensive root resorption (≥1/3 root length) yet vital pulp, the most appropriate pulpal treatment is:

A

pulpotomy

B

pulpectomy

C

extraction

D

apexification

Q147

Which of the following is the most appropriate antibiotic prophylaxis regimen for a patient with a prosthetic heart valve undergoing a dental extraction?

A

Amoxicillin 2 g orally 1 hour before procedure

B

Clindamycin 600 mg orally 1 hour before procedure

C

Azithromycin 500 mg orally 1 hour before procedure

D

Cefazolin 1 g IV 30 minutes before procedure

Q148

Which molecular pattern is recognized by Toll-like receptor 2 (TLR2) on oral epithelial cells to detect Gram-positive bacteria?

A

Lipopolysaccharide

B

Peptidoglycan

C

Flagellin

D

CpG DNA

Q149

Which clinical sign is most indicative of an 'Acute Apical Abscess' as opposed to 'Acute Apical Periodontitis'?

A

Tenderness to percussion

B

Presence of localized swelling and fluctuance

C

Pain upon biting

D

Slight extrusion of the tooth

Q150

A 55-year-old woman with chronic graft-versus-host disease presents with a white, lace-like pattern and erythema on the buccal mucosa that is non-scrapable. Which oral lesion is most characteristic?

A

Oral lichen planus

B

Chronic hyperplastic candidiasis

C

GVHD-related oral mucosal changes

D

Oral squamous cell carcinoma

Q151

After a child brushes with fluoride toothpaste, what is the minimum recommended waiting time before applying a fluoride varnish in the same appointment?

A

Immediately

B

30 minutes

C

1 hour

D

2 hours

Q152

What is the primary reason for incorporating a stress-breaker into a mandibular removable partial denture?

A

Increase retention

B

Reduce torque on abutments

C

Increase stability

D

Reduce occlusal contacts

Q153

In a three-unit bridge, if the pontic is a mandibular first molar, which pontic design is the most appropriate to balance hygiene and aesthetics?

A

Ovate pontic

B

Modified ridge lap pontic

C

Spheroidal pontic

D

Hygienic (Sanitary) pontic

Q154

Which scenario exemplifies a prohibited 'dual relationship' according to the Nepal Dental Council's code?

A

Treating a close family member for a routine check-up

B

Providing care to a colleague's child after obtaining written consent

C

Offering dental treatment to a patient who is also a business partner in a dental supply firm

D

Accepting a referral from a former professor

Q155

What is the effect of increasing the water-to-powder ratio in the mixing of dental stone?

A

Increased compressive strength

B

Decreased setting expansion

C

Increased porosity and decreased strength

D

Decreased setting time

Q156

Which type of collagen is the predominant structural protein found in the organic matrix of enamel?

A

Type I collagen

B

Type II collagen

C

Type III collagen

D

Enamel contains negligible collagen

Q157

Which permanent tooth typically exhibits a single root with a pronounced distal curvature in the apical third?

A

Maxillary canine

B

Mandibular canine

C

Maxillary first premolar

D

Mandibular first premolar

Q158

Which clinical characteristic most reliably differentiates a malignant ulcer from a traumatic ulcer in the oral cavity?

A

Indurated, rolled margins

B

Pain that resolves with analgesics

C

Complete healing within two weeks

D

Presence of granulation tissue

Q159

A patient presents with a 'step-off' deformity at the infraorbital rim and numbness in the cheek area. Which nerve is most likely compromised?

A

Mental nerve

B

Infraorbital nerve

C

Facial nerve

D

Greater palatine nerve

Q160

When maintaining dental unit waterlines for a clinic that treats immunocompromised patients, which disinfectant should be used daily?

A

1% sodium hypochlorite

B

0.1% chlorhexidine

C

1% chlorhexidine gluconate

D

0.05% sodium hypochlorite

Q161

Which property of zirconia contributes most to its excellent biocompatibility when used as a crown material?

A

High surface roughness

B

Low Young's modulus

C

Chemical inertness

D

High porosity

Q162

The Silness-Löe Plaque Index scores plaque on how many surfaces per tooth?

A

Two

B

Four

C

Six

D

Eight

Q163

Which medication used for osteoporosis has been shown to reduce alveolar bone loss in periodontitis patients?

A

Alendronate

B

Risedronate

C

Teriparatide

D

Denosumab

Q164

A digital intraoral sensor requires a lower radiation dose than conventional E-speed film. Approximately what percentage reduction in dose is achieved with a typical CMOS sensor?

A

90-95%

B

50-60%

C

30-40%

D

10-15%

Q165

Which of the following best describes the 'hand-over-mouth' signal in a child undergoing dental treatment?

A

An indication of pain

B

A request for the dentist to stop the procedure

C

A non-verbal request for assistance or withdrawal

D

A sign of cooperation

Q166

Which policy document provides the framework for integrating oral health services into school health programmes across Nepal?

A

National Health Policy 2015

B

School Health Services Directive

C

National Oral Health Action Plan

D

Ministry of Education Curriculum Guide

Q167

What is the primary advantage of adding leucite crystals to a feldspathic porcelain matrix?

A

increase opacity

B

improve translucency and shade matching

C

reduce shrinkage

D

enhance bonding to metal

Q168

A 5-year-old child presents with a firm, painless submandibular swelling that drains sulfur granules through a sinus tract. Which organism is most likely responsible?

A

Actinomyces israelii

B

Nocardia asteroides

C

Corynebacterium diphtheriae

D

Staphylococcus aureus

Q169

In Bjork's metallic implant studies, the greatest amount of mandibular growth during the pubertal spurt was observed at which anatomical region?

A

Condylar head

B

Coronoid process

C

Mandibular body (gonial angle region)

D

Symphyseal region

Q170

In a Class II composite restoration, the configuration factor (C-factor) is highest when the cavity has which of the following dimensions?

A

Wide occlusal isthmus, shallow depth

B

Narrow occlusal isthmus, deep depth

C

Wide occlusal isthmus, deep depth

D

Narrow occlusal isthmus, shallow depth

Q171

In a patient with a steep mandibular curve of Spee, which tooth arrangement reduces posterior tipping?

A

using a reduced height of the posterior teeth

B

using a greater height of the posterior teeth

C

using a narrower tooth width

D

using a more anterior tooth position

Q172

A 22-year-old patient develops brisk arterial bleeding from the extraction socket after mandibular third molar removal. The most appropriate immediate management is:

A

Direct pressure with gauze and rolled petrolatum for 15 minutes

B

Ligation of the inferior alveolar artery

C

Systemic antibiotics

D

IV corticosteroids

Q173

The delayed expansion observed with zinc oxide-eugenol cement after setting is caused by:

A

Hydrolysis of the polymer network

B

Formation of polyether chains

C

Conversion of eugenol to acetaldehyde

D

Cross-linking with zinc ions

Q174

A 35-year-old man with a history of uncontrolled diabetes presents with multiple erythematous papules with a "cobblestone" appearance on the soft palate, which bleed on slight trauma. Which condition is most likely?

A

Necrotizing ulcerative periodontitis

B

Papillary hyperplasia associated with denture wear

C

Peripheral giant cell granuloma

D

Vascular malformation (hemangioma)

Q175

In Angle's Class II Division 2 malocclusion, the mandibular incisors are typically:

A

Retroclined with deep overbite

B

Proclined with increased overjet

C

Midline shifted to the left

D

Widely spaced with open bite

Q176

Which of the following is the most appropriate splinting duration for a lateral luxation injury of a permanent tooth?

A

1 week

B

2 weeks

C

4 weeks

D

8 weeks

Q177

Which of the following is a primary role of 'Histatins' found in human saliva?

A

Activation of B-cells

B

Strong antifungal activity against Candida albicans

C

Degradation of dental plaque

D

Neutralization of salivary acids

Q178

Which collagen type predominates in the periodontal ligament?

A

type I

B

type II

C

type III

D

type IV

Q179

During a routine dental visit, a 4-year-old child receives a topical fluoride varnish. Which statement best explains why this varnish remains effective for several months after application?

A

It forms a durable barrier that never dissolves

B

It continuously releases fluoride into saliva over time

C

It stimulates new enamel formation

D

It permanently inhibits bacterial adhesion

Q180

The 'Critical pH' of enamel is approximately 5.5. If the pH drops to 4.5, what happens to the equilibrium of the hydroxyapatite crystal?

A

Calcium and phosphate ions move from the enamel into the saliva

B

Calcium and phosphate ions move from the saliva into the enamel

C

The crystal remains stable due to the buffering capacity of saliva

D

Fluoride ions are spontaneously released from the crystal lattice

Q181

Which obturating material is contraindicated for primary tooth pulpectomy because it is not resorbable and may interfere with eruption of the permanent successor?

A

Zinc oxide eugenol paste

B

Iodoform-calcium hydroxide paste

C

Calcium hydroxide cement

D

Resin-modified glass ionomer

Q182

According to G.V. Black's principles, the correct sequence of steps in cavity preparation is: removal of caries, establishment of resistance form, establishment of retention form, and final cavity refinement. Which of the following sequences reflects this order?

A

Outline form, removal of caries, resistance form, retention form

B

Removal of caries, resistance form, retention form, outline form

C

Retention form, resistance form, removal of caries, outline form

D

Removal of caries, retention form, resistance form, outline form

Q183

On CBCT, which finding most strongly suggests an odontogenic keratocyst rather than a dentigerous cyst?

A

Scalloped lesion margins with minimal cortical expansion

B

Well-defined sclerotic border surrounding an impacted tooth

C

Large unilocular radiolucency attached to the tooth crown

D

Presence of internal calcifications

Q184

What is the primary reason for using a light-bodied material in the central portion of a fixed prosthodontic impression?

A

To reduce the overall impression volume

B

To achieve intricate detail in interproximal margins

C

To increase the strength of the impression

D

To allow better flow to the tray walls

Q185

A patient receiving rituximab (anti-CD20 therapy) requires an elective dental extraction. When should the procedure be scheduled after the last infusion?

A

1 week

B

2 weeks

C

4 weeks

D

8 weeks

Q186

Which permanent tooth most commonly exhibits a '+' groove pattern (a central groove crossed by a transverse supplemental groove) on its occlusal surface?

A

Maxillary first premolar

B

Mandibular first molar

C

Maxillary lateral incisor

D

Mandibular second premolar

Q187

Which of the following interventions is recommended for children aged 6-12 years in the national school-based oral health programme?

A

Surgical tooth extraction

B

Supervised fluoride mouth rinse

C

Orthodontic assessment

D

Cosmetic teeth whitening

Q188

The Williams periodontal probe has markings at 1, 2, 3, 5, 7, 8, 9, and 10 mm. What is the primary purpose of the 3 mm marking?

A

to detect the depth of a healthy sulcus

B

to identify the cementoenamel junction on anterior teeth

C

to measure furcation involvement

D

to assess gingival recession

Q189

In a Kennedy Class IV arch, the primary challenge in RPD design is typically:

A

Lack of indirect retention

B

Excessive torque on the posterior teeth

C

The length of the anterior edentulous span

D

The inability to use a major connector

Q190

Which systemic medication class is most commonly associated with xerostomia that predisposes to periodontal disease?

A

Anticholinergic drugs

B

Beta-blockers

C

ACE inhibitors

D

Statins

Q191

During a routine periodontal assessment, a practitioner uses a probe with a recommended force of approximately how many grams to avoid tissue trauma?

A

10–20 grams

B

30–45 grams

C

60–80 grams

D

100–120 grams

Q192

Which component of glass ionomer cement is primarily responsible for its acid–base reaction and subsequent fluoride release, contributing to its biocompatibility?

A

Polyalkenoic acid

B

Hydroxyethyl methacrylate

C

Silane coupling agent

D

Bis-GMA

Q193

Which hepatic cytochrome P450 isoform is primarily responsible for the oxidative de-ethylation of lidocaine?

A

CYP1A2

B

CYP2D6

C

CYP3A4

D

CYP2C9

Q194

A patient with immune thrombocytopenic purpura (platelet count 30 × 10⁹/L) undergoes extraction of a lower premolar. Post-operative bleeding persists despite pressure. Which emergency measure is most appropriate?

A

Transfuse packed red blood cells

B

Administer intravenous tranexamic acid and arrange platelet transfusion

C

Apply topical epinephrine gel

D

Give subcutaneous heparin

Q195

A failure of the palatal shelves to fuse in the midline results in a cleft palate. This fusion typically occurs in which direction?

A

Anterior to posterior

B

Posterior to anterior

C

Lateral to medial

D

Superior to inferior

Q196

In the context of complete denture occlusion, the term "monoplane occlusion" refers to which of the following characteristics?

A

Use of non-anatomic teeth set on a flat plane without cusp angles

B

Arrangement of teeth with a pronounced curve of Spee

C

Inclusion of posterior teeth with deep lingual cusps

D

Placement of teeth following the Camper's line

Q197

The most appropriate radiographic technique for diagnosing a suspected periapical cyst in a mandibular molar is

A

Panoramic radiograph

B

Bitewing radiograph

C

Conventional periapical radiograph with paralleling technique

D

CBCT

Q198

For virtual implant planning, which software capability is essential to align the CBCT dataset with a digital impression?

A

Surface matching/registration

B

Automatic segmentation of the mandibular canal

C

Dose reporting module

D

Three-dimensional volume rendering

Q199

During open flap debridement of a buccal intrabony defect, which flap architecture best facilitates primary intention healing while preserving the interdental papilla?

A

Modified Widman flap

B

O'Leary flap

C

Langer flap

D

Twin flap

Q200

A hyperdivergent (vertical) growth pattern is cephalometrically characterized by:

A

Increased SN-GoGn angle

B

Decreased lower facial height

C

Deep bite

D

Reduced mandibular plane angle