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Examen Estatal de Estomatología study materials
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Examen Estatal de Estomatología practice questions

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Question 1Caries activity, mineral balance and restorative material mechanisms

What is the micromechanical bonding purpose of enamel acid conditioning in an appropriate resin adhesive system, without specifying one concentration or exposure time for every product?

  1. Selectively dissolving hydroxyapatite crystals to create micro-porosities for resin tag micromechanical retention Correct answer.
  2. Completely dissolving the collagen network within the dentin matrix
  3. Sterilizing the cavity floor to eliminate anaerobic pulp bacteria
  4. Forming a covalent chemical bond between calcium phosphate and composite monomers

Explanation

Acid etching of enamel with 35-37% phosphoric acid selectively dissolves prism cores or prism peripheries, creating high-energy micro-porosities (depth of 10-30 micrometers). Fluid resin bonding agents penetrate these micro-irregularities by capillary action, polymerizing to form micromechanical resin tags.

Question 2Caries activity, mineral balance and restorative material mechanisms

In contemporary adhesive systems, what defines the 'hybrid layer' originally described by Nakabayashi?

  1. The micromechanical interdiffusion zone formed by resin monomers polymerizing within demineralized dentin collagen fibrils Correct answer.
  2. The chemical bond between glass ionomer polyacrylic acid and hydroxyapatite
  3. The layer of residual cutting debris compacted into dentinal tubules (smear plug)
  4. The interface formed between the glass filler particles and silane coupling agent

Explanation

The hybrid layer (zone d'hybridation) is formed when adhesive hydrophilic monomers (e.g., HEMA, Bis-GMA) infiltrate the exposed collagen fibril meshwork produced by acid demineralization of dentin and polymerize in situ, creating a molecular-level mechanical interlocking between tooth structure and restorative resin.

Question 3Caries activity, mineral balance and restorative material mechanisms

During a routine clinical examination under clean, dry conditions with adequate lighting, a clinician observes an opaque, chalky white spot lesion (mancha blanca) on the cervical third of the facial surface of tooth 11. What is the fundamental histological characteristic of this non-cavitated early carious lesion?

  1. Total cavitary collapse of the outer enamel with exposed infected tubular dentin
  2. Subsurface demineralization with an intact, relatively hypermineralized external surface layer Correct answer.
  3. Complete pulp chamber obliteration by secondary reparative dentin
  4. Extensive bacterial colonization of the odontoblastic layer with micro-abscess formation

Explanation

Histologically, the incipient enamel carious lesion (white spot lesion) is characterized by subsurface demineralization (body of the lesion exhibiting 5% to 25% pore volume) beneath a relatively intact and well-mineralized outer surface zone (~30-50 micrometers thick), maintained by constant surface remineralization dynamics from saliva.

Question 4Endodontic diagnosis, disinfection, and structural prognosis

What does a conventional electric pulp test primarily assess?

  1. Neural response rather than direct pulpal blood flow Correct answer.
  2. The amount of calcium in root dentin
  3. The exact number of living pulp cells
  4. The diameter of the apical foramen

Explanation

Electric pulp testing elicits a sensory response and must be interpreted with other findings because it does not directly demonstrate pulpal circulation.

Question 5Endodontic diagnosis, disinfection, and structural prognosis

A recently traumatized immature permanent incisor does not respond to a sensibility test. What is the best interpretation?

  1. The tooth necessarily has a vertical root fracture
  2. Immediate extraction is required in every case
  3. The result proves that apical growth has stopped permanently
  4. One negative test alone does not establish pulp necrosis Correct answer.

Explanation

After trauma and in immature teeth, neural responsiveness may be unreliable; diagnosis should integrate history, serial testing, examination, and imaging.

Question 6Periodontal diagnosis, risk, and long-term stability

What finding most directly distinguishes periodontitis from plaque-induced gingivitis on an otherwise intact periodontium?

  1. Redness limited to the gingival margin
  2. Bleeding after gentle probing alone
  3. Loss of periodontal attachment attributable to periodontal disease Correct answer.
  4. Visible supragingival plaque alone

Explanation

Periodontitis involves destruction of the tooth-supporting attachment apparatus; bleeding and redness alone can occur with reversible gingival inflammation.

Question 7Periodontal diagnosis, risk, and long-term stability

A site has a probing depth of 4 mm and gingival recession of 2 mm from the cementoenamel junction. What is its clinical attachment level?

  1. 8 mm
  2. 6 mm Correct answer.
  3. 4 mm
  4. 2 mm

Explanation

With the gingival margin apical to the cementoenamel junction, clinical attachment loss is the probing depth plus recession.

Question 8Restore function while respecting structure and supporting tissues

How do retention and resistance form differ for a conventional crown preparation?

  1. Retention opposes removal along the path of insertion; resistance opposes other dislodging forces Correct answer.
  2. Retention is the same as pulpal vitality
  3. Both refer only to the shade of ceramic
  4. Resistance means the tooth has no caries

Explanation

Preparation geometry should help resist both withdrawal and functional tipping; these related mechanical requirements are distinct from esthetics or the biological state of the tooth.

Question 9Restore function while respecting structure and supporting tissues

What is the purpose of a ferrule in restoring a structurally compromised endodontically treated tooth?

  1. It makes every root fracture repairable
  2. The ferrule sterilizes the root canal
  3. A band of remaining coronal tooth structure helps resist functional fracture stresses Correct answer.
  4. A post automatically replaces the need for sound tooth structure

Explanation

A ferrule uses remaining tooth structure encircled by the restoration to improve stress management; prognosis still depends on the overall tooth and restorative design.

Question 10Surgical assessment, anatomy, bleeding, and complications

Which sensory deficit most directly suggests inferior alveolar nerve involvement after mandibular surgery?

  1. Altered sensation of the lower lip and chin Correct answer.
  2. Loss of vision in one eye
  3. Loss of shoulder abduction
  4. Isolated numbness of the forehead

Explanation

The inferior alveolar nerve continues through the mental nerve to supply the lower lip and chin, making these areas useful for sensory assessment.

Question 11Surgical assessment, anatomy, bleeding, and complications

Which structure is particularly relevant to altered general sensation of the tongue after lower third-molar surgery?

  1. Phrenic nerve
  2. Greater occipital nerve
  3. Lingual nerve Correct answer.
  4. Optic nerve

Explanation

The lingual nerve supplies general sensation to the anterior tongue and lies near the mandibular third-molar region, creating a recognized surgical risk.

Question 12Describe lesions, construct differentials, and obtain a diagnosis

A persistent indurated ulcer on the lateral tongue has no clear traumatic explanation. What is the most appropriate next diagnostic priority?

  1. Observation indefinitely without documentation
  2. Prompt specialist assessment and biopsy planning Correct answer.
  3. Repeated polishing of adjacent intact teeth as definitive management
  4. Reassurance that all painless ulcers are harmless

Explanation

A persistent unexplained indurated ulcer is a concerning finding; a timely tissue diagnosis or appropriate referral takes priority over unsupported reassurance.

Question 13Describe lesions, construct differentials, and obtain a diagnosis

What does the clinical term leukoplakia describe?

  1. A predominantly white oral patch diagnosed after excluding other definable causes Correct answer.
  2. Any white material that wipes off the mucosa
  3. A guaranteed benign response to spicy food
  4. A histologic diagnosis of invasive carcinoma in every case

Explanation

Leukoplakia is a clinical exclusion diagnosis for a white lesion; histopathology is needed when indicated to evaluate dysplasia or another underlying process.

Question 14Care for the developing dentition with risk-based decisions

Why does the frequency of fermentable carbohydrate exposure matter in caries risk assessment?

  1. Repeated acid challenges can limit the time available for remineralization Correct answer.
  2. Only the color of the food affects caries
  3. Frequency has no effect if total daily intake is unchanged
  4. All carbohydrates permanently sterilize plaque

Explanation

Caries risk reflects the balance of repeated demineralizing challenges and protective factors, so exposure pattern is relevant alongside quantity, fluoride, and biofilm control.

Question 15Care for the developing dentition with risk-based decisions

What is the main anticaries purpose of topical fluoride varnish?

  1. Change primary teeth into permanent teeth
  2. Support remineralization and reduce susceptibility to demineralization Correct answer.
  3. Remove every established cavitated lesion
  4. Replace all need for plaque control

Explanation

Topical fluoride supports mineral balance at the tooth surface, but its use complements risk reduction and does not mechanically restore a cavitated defect.

Question 16Diagnose the cause before selecting mechanics or appliances

What biological process permits orthodontic tooth movement under controlled force?

  1. Remodeling of the periodontal ligament and adjacent alveolar bone Correct answer.
  2. Permanent dissolution of all root cementum
  3. Immediate stretching of enamel into a new shape
  4. Movement of the crown while the root remains fixed forever

Explanation

Orthodontic force produces tissue responses in the periodontal ligament and surrounding bone, allowing movement through coordinated remodeling rather than reshaping enamel.

Question 17Diagnose the cause before selecting mechanics or appliances

What does anchorage describe in orthodontic mechanics?

  1. The color of the brackets
  2. Resistance to unwanted movement of supporting teeth or structures Correct answer.
  3. A guarantee that no tooth will move
  4. The amount of fluoride in a mouth rinse

Explanation

Anchorage planning controls where reaction forces are expressed, helping achieve intended movement while limiting undesirable displacement of the supporting unit.

Question 18Imaging justification, geometry, and responsible interpretation

What is the principal justification for prescribing dental imaging?

  1. Replacement of history taking
  2. A clinical question for which the expected diagnostic benefit outweighs the imaging risk Correct answer.
  3. The patient's request for the largest image volume regardless of need
  4. A fixed need for every possible image at every visit

Explanation

Imaging selection follows clinical assessment and a defined diagnostic purpose, rather than indiscriminate exposure or a belief that more images always improve care.

Question 19Imaging justification, geometry, and responsible interpretation

When CBCT is indicated, what field of view should generally be chosen?

  1. The smallest field sufficient to answer the clinical question Correct answer.
  2. A field that intentionally excludes the lesion
  3. The largest available field for every patient
  4. A field selected only by the patient's height

Explanation

Field selection balances diagnostic coverage against unnecessary exposure, while still including the anatomy required to answer the specific clinical question.

Question 20Read evidence and design programs for the population

What does the prevalence of untreated caries describe in a defined survey population?

  1. Only new cases arising during future follow-up
  2. The probability that treatment will succeed
  3. The number of restorations placed per clinician
  4. The proportion with untreated caries at the specified assessment time Correct answer.

Explanation

Prevalence describes existing disease within a defined population and time frame, so its interpretation depends on the case definition and who was assessed.

Question 21Read evidence and design programs for the population

What does disease incidence measure in a longitudinal study?

  1. All cases ever diagnosed without a time reference
  2. Only the severity of disease at baseline
  3. The percentage of participants satisfied with the clinic
  4. New cases developing among the population at risk over a defined period Correct answer.

Explanation

Incidence concerns the occurrence of new disease over time among people initially at risk, distinguishing it from the burden of existing cases.

Question 22Prevent infection and prepare for physiological deterioration

Why can pulse oximetry alone be insufficient to detect early hypoventilation during sedation?

  1. Oxygen saturation may remain acceptable while ventilation deteriorates, especially with supplemental oxygen Correct answer.
  2. The monitor replaces continuous clinical observation
  3. Pulse oximetry directly measures exhaled carbon dioxide
  4. Normal saturation proves the airway cannot obstruct

Explanation

Oxygenation and ventilation are different physiological functions, so monitoring plans must not assume that a saturation reading provides a complete assessment of breathing.

Question 23Prevent infection and prepare for physiological deterioration

What information does capnography principally provide during procedural sedation?

  1. A direct measurement of pulpal blood flow
  2. The exact depth of dental caries
  3. The total number of viable oral bacteria
  4. Exhaled carbon dioxide patterns that help assess ventilation Correct answer.

Explanation

Capnography provides breath-related carbon dioxide information and waveform trends, supporting recognition of ventilatory problems alongside other monitoring and direct patient assessment.

Question 24Caries activity, mineral balance and restorative material mechanisms

Glass ionomer cement (Cemento de Vidrio Ionómero - CVI) is widely used in Cuban restorative and atraumatic restorative treatment (ART) protocols. By what precise mechanism does conventional glass ionomer achieve true chemical adhesion to dental structures?

  1. Micromechanical interlocking through resin tags formed inside acid-etched dentinal tubules
  2. Polymerization shrinkage creating a vacuum seal against dentin walls
  3. Ionic exchange and chelation between carboxyl groups of polyacrylic acid and calcium ions in hydroxyapatite Correct answer.
  4. Covalent peptide bonding with organic type I collagen fibrils in the presence of silane coupling agents

Explanation

Conventional glass ionomer cements adhere chemically to enamel and dentin through an ionic chelation mechanism: the carboxylate groups (-COO-) of the polyacrylic acid chains form ionic bonds with the calcium (Ca2+) and phosphate ions present in the hydroxyapatite crystals of the tooth substrate.

Question 25Caries activity, mineral balance and restorative material mechanisms

When placing a direct composite resin restoration using a total-etch (grabado total / etch-and-rinse) adhesive system, what is the clinical danger of excessively air-drying (desiccating) the acid-etched dentin prior to primer application?

  1. Accelerated enamel remineralization preventing resin monomer infiltration
  2. Immediate pulp necrosis caused by excessive thermal conduction
  3. Dissolution of the inorganic hydroxyapatite crystals by residual water
  4. Collapse of the exposed collagen fibril meshwork, preventing monomer infiltration and compromising hybrid layer formation Correct answer.

Explanation

Acid etching with 37% phosphoric acid removes the smear layer and dissolves peri- and intertubular hydroxyapatite, exposing a delicate scaffolding of type I collagen fibrils. If dentin is excessively desiccated, the water supporting this collagen scaffold evaporates, causing the fibrils to collapse into a dense, impermeable mat that prevents hydrophilic primer monomers from penetrating, resulting in a defective hybrid layer, poor bond strength, and postoperative sensitivity.

Question 26Endodontic diagnosis, disinfection, and structural prognosis

A 12-year-old patient presents with extensive carious breakdown of the coronal enamel on permanent tooth 36. Inside the open carious cavity, a bright red-pink, fleshy, pedunculated mass of soft tissue protrudes into the occlusal space. The mass bleeds easily when probed but is essentially insensitive to light touch. The roots are still developing. What is this condition?

  1. Ameloblastoma of the mandibular angle
  2. Chronic hyperplastic pulpitis (Pulp polyp / Pulpitis crónica hiperplásica) Correct answer.
  3. Squamous cell carcinoma of the alveolar ridge
  4. Acute apical abscess with sinus tract

Explanation

Chronic hyperplastic pulpitis (pulp polyp) occurs in children and adolescents with young, highly vascularized pulps and open carious exposures. The chronic low-grade irritation stimulates the proliferation of exuberant granulation tissue that erupts from the pulp chamber into the cavity, becoming covered by desquamated oral epithelial cells.

Question 27Endodontic diagnosis, disinfection, and structural prognosis

A 50-year-old patient presents with dark grayish discoloration of the clinical crown of tooth 21 following a sports injury sustained 10 years ago. Thermal tests (refrigerant cold spray and heated gutta-percha) and electric pulp testing produce no response whatsoever. The tooth is completely non-tender to percussion and palpation, and periapical radiography shows no radiolucency. What is the diagnosis?

  1. Pulp hyperemia
  2. Acute serous pulpitis
  3. Internal root resorption with active vascularity
  4. Pulp necrosis (Necrosis pulpar) Correct answer.

Explanation

Pulp necrosis represents the complete cessation of pulpal blood flow and destruction of sensory innervation. Clinical signs include complete lack of response to thermal and electric pulp vitality testing, loss of tooth translucency with coronal grayish discoloration (from hemoglobin breakdown products penetrating dentinal tubules), and absence of pain unless periapical involvement develops.

Question 28Endodontic diagnosis, disinfection, and structural prognosis

A patient has localized pain on biting tooth 35, marked vertical percussion tenderness and widening of the apical periodontal-ligament space. Comparative thermal sensibility testing is nonresponsive. Which listed apical diagnostic category best fits these findings?

  1. Acute apical periodontitis (Periodontitis apical aguda) Correct answer.
  2. Pulp hyperemia
  3. Chronic apical abscess with fistulous tract
  4. Periodontal pocket without occlusal trauma

Explanation

Acute apical periodontitis is an acute inflammation of the apical periodontal ligament, clinically characterized by well-localized pain, extreme tenderness to vertical percussion and mastication, and the subjective sensation that the tooth is extruded ('tall'). It typically arises as a sequel to pulp necrosis.

Question 29Endodontic diagnosis, disinfection, and structural prognosis

A 38-year-old patient presents with rapid, severe swelling of the upper right face. Examination reveals a non-vital tooth 14, extreme pain to the slightest touch, and a tense, fluctuant submucosal swelling in the canine fossa. The patient has a low-grade fever (38.1 °C) and regional lymphadenopathy. What is the clinical diagnosis under Cuban stomatological norms?

  1. Chronic periapical granuloma
  2. Acute alveolar abscess (Absceso alveolar agudo) Correct answer.
  3. Benign pleomorphic adenoma of minor salivary glands
  4. Gingival fibromatosis

Explanation

An acute alveolar abscess (absceso alveolar agudo) is an acute purulent infection originating from a necrotic pulp that breaks through the cortical plate, presenting with severe throbbing pain, exquisite tenderness to touch, regional fluctuant soft-tissue swelling, and systemic manifestations such as fever and lymphadenopathy.

Question 30Endodontic diagnosis, disinfection, and structural prognosis

In the histopathological and clinical differential diagnosis of asymptomatic periapical radiolucencies, what definitive histological feature distinguishes a true periapical cyst (quiste periapical verdadero) from a periapical granuloma (granuloma periapical)?

  1. The presence of purulent staphylococcal colonies inside root canals
  2. The complete absence of lymphocytes, plasma cells, and histiocytes
  3. A central pathological lumen fully enclosed and lined by non-keratinized stratified squamous epithelium derived from Malassez epithelial rests Correct answer.
  4. The formation of mature cortical lamellar bone within the periapical radiolucency

Explanation

A true periapical cyst (radicular cyst) is histopathologically defined by a closed pathological lumen filled with fluid or cholesterol crystals and completely surrounded by an epithelial lining of non-keratinized stratified squamous epithelium, originating from the proliferation of the epithelial rests of Malassez stimulated by chronic inflammation. In contrast, a granuloma consists of vascularized granulation tissue infiltrated by chronic inflammatory cells without an epithelial-lined central lumen.

Question 31Endodontic diagnosis, disinfection, and structural prognosis

Electric Pulp Testing (EPT) is an important diagnostic adjunct in endodontics. What specific biological component does EPT stimulate, and what is its primary diagnostic limitation in newly erupted traumatized teeth?

  1. It measures true vascular blood flow; its limitation is false positive responses in necrotic pulps
  2. It stimulates intrapulpal baroreceptors; its limitation is that it requires general anesthesia
  3. It evaluates pulpal lymphatic drainage; its limitation is interference from salivary fluoride
  4. It stimulates sensory nerve conduction (primarily A-delta fibers); its limitation is frequent false-negative responses in immature teeth with incomplete innervation Correct answer.

Explanation

Electric pulp testers generate a high-frequency electrical current that stimulates sensory myelinated A-delta nerve fibers at the pulp-dentin junction. However, EPT assesses sensory neural conduction rather than true vascular supply. In newly erupted or traumatized young teeth with open apices, the Raschkow neural plexus is not fully mature, leading to frequent false-negative readings despite a fully viable vascular supply.

Question 32Endodontic diagnosis, disinfection, and structural prognosis

Sodium hypochlorite (NaOCl) is the primary irrigating solution in endodontic therapy. What unique property makes NaOCl indispensable during biomechanical root canal preparation compared to other antimicrobial irrigants like chlorhexidine or saline?

  1. It completely dissolves inorganic smear layer and decalcifies peritubular dentin
  2. It possesses the unique dual ability to act as a broad-spectrum antimicrobial agent AND actively dissolve necrotic and vital organic pulpal tissue Correct answer.
  3. It bonds chemically to gutta-percha to form an impermeable hermetic apical seal
  4. It stimulates rapid periapical osteogenesis when extruded past the apical foramen

Explanation

Sodium hypochlorite (NaOCl in concentrations from 0.5% to 5.25%) is the gold-standard endodontic irrigant because it is the only clinically viable solution that combines potent, rapid broad-spectrum antimicrobial activity with the unique capacity to dissolve both vital and necrotic organic tissue. It does not dissolve inorganic dentin debris, which requires a chelator such as EDTA.

Question 33Periodontal diagnosis, risk, and long-term stability

What is the origin of the mineral salts that form subgingival calculus (tártaro o cálculo subgingival), and why is it typically dark brown or greenish-black in clinical appearance?

  1. Minerals originate from acidic foods; dark color is caused by coffee and tea consumption
  2. Minerals originate from dental enamel; dark color is due to dentin tubules leaking melanin
  3. Minerals originate primarily from gingival crevicular fluid (serum transudate/exudate); dark color is caused by the breakdown of blood pigments (hemoglobin and hemosiderin) Correct answer.
  4. Minerals originate from bacterial saliva enzymes; dark color is caused by heavy tobacco smoking only

Explanation

Subgingival calculus is formed through the mineralization of subgingival biofilm driven by minerals (calcium and phosphate) supplied by gingival crevicular fluid (GCF). Its characteristic dark brown, greenish-black color results from the presence of blood breakdown products (hemoglobin, hematin, hemosiderin) produced during chronic subgingival bleeding.

Question 34Periodontal diagnosis, risk, and long-term stability

A 21-year-old patient presents with generalized redness, marginal edema, and bleeding on gentle probing across the gingival margin. Clinical examination reveals intact alveolar bone heights on radiographs and probe depths of 2 to 3 mm with zero clinical attachment loss (CAL = 0 mm). What is the definitive clinical diagnosis?

  1. Aggressive periodontitis
  2. Chronic periodontitis with vertical bone defects
  3. Atrophic gingivosis
  4. Chronic plaque-induced gingivitis (Gingivitis crónica inducida por placa) Correct answer.

Explanation

Chronic plaque-induced gingivitis is an inflammatory lesion confined strictly to the marginal gingiva, characterized by erythema, edema, loss of normal stippling, and bleeding on probing, with NO apical migration of the junctional epithelium (no clinical attachment loss) and NO alveolar bone resorption.

Question 35Periodontal diagnosis, risk, and long-term stability

A 19-year-old military recruit under severe physical and emotional stress presents with acute, intense gingival pain, spontaneous bleeding, and severe halitosis. Clinical examination reveals 'punched-out', crater-like, necrotic ulcerations of the interdental papillae covered by a grayish pseudomembrane. What is the diagnosis?

  1. Desquamative gingivitis associated with pemphigus vulgaris
  2. Necrotizing Ulcerative Gingivitis (Gingivitis Úlcero-Necrosante Aguda - GUNA / Vincent's infection) Correct answer.
  3. Chronic fibrous gingivitis
  4. Primary herpetic gingivostomatitis

Explanation

Necrotizing Ulcerative Gingivitis (GUNA) is an acute, painful bacterial infection characterized pathognomonically by necrotic, 'punched-out' interdental papillae, pseudomembranous sloughing, spontaneous bleeding, severe pain, and fetid oral odor (halitosis), often triggered by psychological stress, smoking, and poor hygiene.

Question 36Periodontal diagnosis, risk, and long-term stability

A 55-year-old hypertensive patient presents with painless, firm, lobulated, pale pink enlargement of the gingival tissues that originated in the interdental papillae and now covers the cervical third of the anterior crowns. The patient denies systemic signs and takes nifedipine daily. What is the diagnosis and appropriate management?

  1. Acute leukemia-associated gingivitis; immediate bone marrow biopsy
  2. Hereditary gingival fibromatosis; full mouth immediate extractions
  3. Drug-induced gingival enlargement (Agrandamiento gingival medicamentoso); plaque control, consultation with prescribing physician to consider drug substitution, and surgical gingivectomy if persistent Correct answer.
  4. Gingival tuberculosis; immediate triple antibiotic antitubercular regimen

Explanation

The described gingival enlargement is consistent with a medication-associated contribution in a patient using nifedipine. Plaque-related inflammation and other causes still need assessment. Any change to prescribed cardiovascular treatment requires coordination with the responsible prescriber; the dentist or patient should not stop it unilaterally. Further periodontal management depends on the actual response and diagnosis.

Question 37Periodontal diagnosis, risk, and long-term stability

When assessing a patient for periodontitis, how is Clinical Attachment Loss (CAL / Nivel de Inserción Clínica - NIC) accurately measured using a periodontal probe?

  1. From the incisal edge to the marginal gingival crest
  2. From the mucogingival junction to the base of the periodontal pocket
  3. From the contact point of adjacent teeth to the alveolar bone crest
  4. From the cementoenamel junction (CEJ / línea amelocementaria) to the base of the probed periodontal pocket Correct answer.

Explanation

Clinical Attachment Loss (CAL) is defined as the pathological distance from a fixed anatomical landmark-the cementoenamel junction (CEJ)-to the base of the periodontal pocket or sulcus. Probing pocket depth (PPD), by contrast, measures from the fluctuating gingival margin to the pocket base.

Question 38Periodontal diagnosis, risk, and long-term stability

During non-surgical periodontal therapy (raspado y alisado radicular - RAR), a periodontist selects area-specific Gracey curettes. Which specific Gracey curette pair is designed exclusively for instrumentation of the mesial surfaces of posterior molars and premolars?

  1. Gracey 1-2
  2. Gracey 7-8
  3. Gracey 13-14
  4. Gracey 11-12 Correct answer.

Explanation

Gracey curettes are area-specific instruments with an offset blade angle of 70 degrees to the lower shank. Gracey 11-12 is designed specifically for the mesial surfaces of posterior teeth, while Gracey 13-14 is designed for distal surfaces of posterior teeth.

Question 39Periodontal diagnosis, risk, and long-term stability

What is the key pathological distinction between Primary Occlusal Trauma (Trauma oclusal primario) and Secondary Occlusal Trauma (Trauma oclusal secundario)?

  1. Primary occlusal trauma affects only primary teeth; secondary affects only permanent teeth
  2. Primary occlusal trauma causes acute pulp necrosis; secondary causes enamel caries
  3. Primary occlusal trauma is infectious; secondary occlusal trauma is purely genetic
  4. Primary occlusal trauma occurs when excessive occlusal forces act on a tooth with healthy, normal bone support; secondary occurs when normal or excessive forces act on a tooth with reduced periodontal support Correct answer.

Explanation

Primary occlusal trauma is defined as tissue injury resulting from excessive occlusal forces applied to a tooth with a normal, healthy periodontal attachment apparatus. Secondary occlusal trauma occurs when normal or excessive occlusal forces cause damage to a periodontium that already exhibits reduced attachment height and bone loss from periodontitis.

Question 40Care for the developing dentition with risk-based decisions

In the analysis of primary dental arch development (arcos de Baume), what are the precise anatomical locations of the physiological 'Primate Spaces' (Espacios primates o de antropoides)?

  1. Between the primary central and lateral incisors in both arches
  2. Mesial to the maxillary primary canines and distal to the mandibular primary canines Correct answer.
  3. Distal to the maxillary second molars and mesial to the mandibular central incisors
  4. Between the first and second primary molars in both arches

Explanation

Primate spaces (espacios primates) are physiological developmental spaces located mesial to the primary canines in the maxilla (between primary lateral incisor and canine) and distal to the primary canines in the mandible (between primary canine and first primary molar). They facilitate normal alignment of erupting permanent incisors and early mesial shift of permanent first molars.

Question 41Care for the developing dentition with risk-based decisions

During a routine panoramic and periapical radiographic survey of an 8-year-old child presenting with a delayed eruption of tooth 11, a small, conical, inverted supernumerary tooth is detected in the palatal midline between the roots of the central incisors. What is this entity called?

  1. Paramolar
  2. Distomolar (fourth molar)
  3. Odontoma complex
  4. Mesiodens (diente supernumerario mesiodens) Correct answer.

Explanation

A mesiodens is the most common supernumerary tooth in human dentition, occurring in the premaxillary midline between the two central incisors. It is typically conical or peg-shaped and often causes delayed eruption, impaction, or ectopia of permanent central incisors.

Question 42Care for the developing dentition with risk-based decisions

A clinical examination of a 7-year-old child reveals an abnormally wide bifid crown on the lower left incisor with a shallow vertical developmental notch. When counting the number of teeth in the dental arch, the clinician finds that counting the bifid tooth as one results in a normal total tooth count (20 primary teeth). What is the diagnosis?

  1. Gemination (Geminación dentaria) Correct answer.
  2. Fusion (Fusión dentaria)
  3. Amelogenesis imperfecta
  4. Concrescence (Concrescencia)

Explanation

Gemination (geminación) occurs when a single tooth germ attempts to divide, resulting in a tooth with a bifid crown and usually a single shared root and root canal. Clinically, counting the anomalous bifid tooth as one results in a normal total number of teeth in the arch. In fusion, two distinct germs unite, resulting in a reduced total tooth count unless fused with a supernumerary tooth.

Question 43Care for the developing dentition with risk-based decisions

A 2-year-old child presents with rampant, extensive carious destruction affecting the labial, palatal, and proximal surfaces of all four maxillary primary incisors, while the mandibular primary incisors are completely sound and free of caries. What clinical condition does this classic pattern represent, and why are the mandibular incisors spared?

  1. Amelogenesis imperfecta; mandibular incisors have thicker enamel than maxillary incisors
  2. Fluorosis grade 4; mandibular incisors do not absorb systemic fluoride
  3. Early Childhood Caries (Caries de la infancia temprana / Caries de biberón); mandibular incisors are protected by the physical covering of the tongue and cleansing salivary flow from submandibular/sublingual glands Correct answer.
  4. Dentinogenesis imperfecta; mandibular incisors lack dentinal tubules

Explanation

This classic presentation is Early Childhood Caries (caries de biberón). Maxillary incisors are immersed in stagnant sugary liquid (milk, sweetened formula) during sleep when salivary flow decreases. The mandibular incisors are spared because they are physically shielded by the protruded resting tongue and bathed by constant salivary secretions from the submandibular and sublingual ducts.

Question 44Care for the developing dentition with risk-based decisions

According to the Ellis and Davey classification of traumatic dental injuries widely used in Cuban stomatological practice, what is an Ellis Class II fracture?

  1. Enamel infraction without loss of tooth structure
  2. Fracture involving enamel only (simple crown fracture)
  3. Complicated crown fracture involving enamel, dentin, and pulp exposure
  4. Extensive fracture of the crown involving enamel and dentin without pulpal exposure Correct answer.

Explanation

In the Ellis and Davey classification: Class I is an enamel-only fracture; Class II is an extensive crown fracture involving enamel and dentin without pulp exposure; Class III is an extensive crown fracture with pulp exposure; and Class IV is a traumatized tooth that has lost pulpal vitality with or without loss of crown structure.

Question 45Describe lesions, construct differentials, and obtain a diagnosis

A 40-year-old patient presents with severe, rapidly spreading, board-like indurated brawny swelling involving both submandibular, sublingual, and submental spaces bilaterally. The floor of the mouth is elevated, the tongue is pushed superiorly and posteriorly against the palate, and the patient has stridor, severe dysphagia, and drooling. What is this life-threatening surgical emergency?

  1. Canine space cellulitis
  2. Ludwig's Angina (Angina de Ludwig) Correct answer.
  3. Sialolithiasis of the parotid gland
  4. Torus mandibularis

Explanation

Ludwig's Angina is a life-threatening, rapidly progressive, bilateral gangrenous cellulitis involving the submandibular, sublingual, and submental fascial spaces, typically originating from infected mandibular molars whose apices lie below the mylohyoid ridge. The hallmark elevation and posterior displacement of the tongue causes acute upper airway obstruction, requiring emergency airway management, high-dose intravenous antibiotics, and surgical decompression.

Question 46Describe lesions, construct differentials, and obtain a diagnosis

A persistent, non-wipeable white patch on the lateral tongue has no established alternative explanation. Which listed diagnostic interpretation is most appropriate before histopathology, without assuming a current Cuban programme rule?

  1. Oral leukoplakia (Leucoplasia bucal); a potentially malignant disorder that requires close surveillance and biopsy to evaluate dysplasia Correct answer.
  2. Acute pseudomembranous candidiasis; easily scraped off with a wooden spatula
  3. Koplik spots of measles; self-limiting within 24 hours
  4. Amalgam tattoo; a purely metallic pigmentation requiring no biopsy

Explanation

According to the World Health Organization (WHO) and PDCB definitions, oral leukoplakia is a predominantly white lesion of the oral mucosa that cannot be wiped off and cannot be characterized clinically or pathologically as any other recognizable disease. It is classified as an oral potentially malignant disorder (OPMD) and requires biopsy to assess epithelial dysplasia.

Question 47Describe lesions, construct differentials, and obtain a diagnosis

A 26-year-old patient presents with pain and joint noise in the right temporomandibular joint (TMJ). Clinical examination reveals a distinct opening click that disappears once the jaw is open, and a reciprocal closing click just before teeth achieve maximum intercuspation. The patient has a normal maximum mouth opening of 45 mm with a slight transient deviation to the right that corrects upon full opening. What is the diagnosis?

  1. Anterior disc displacement without reduction (Desplazamiento discal sin reducción / bloqueo cerrado)
  2. Acute septic arthritis of the temporomandibular joint
  3. Condylar fracture with fibrous ankylosis
  4. Anterior disc displacement with reduction (Desplazamiento discal con reducción) Correct answer.

Explanation

Anterior disc displacement with reduction is characterized by reciprocal clicking: as the condyle translates forward during opening, it slips under the posterior band of the anteriorly displaced disc with a click ('reduction'), restoring normal disc-condyle alignment and allowing normal mouth opening (≥40 mm). During closing, the disc slips anteriorly off the condylar head with a second click just before full closure.

Question 48Surgical assessment, anatomy, bleeding, and complications

What is the primary cellular and molecular mechanism of action of local anesthetic agents (such as lidocaine and mepivacaine) in dental local anesthesia?

  1. Reversible blockade of voltage-gated sodium channels (Nav) from inside the neuronal membrane, preventing sodium influx, membrane depolarization, and action potential propagation Correct answer.
  2. Direct destruction of myelin sheaths surrounding peripheral sensory nerves
  3. Permanent inhibition of acetylcholine release at the neuromuscular junction
  4. Acidification of the extracellular fluid to precipitate intracellular calcium ions

Explanation

Local anesthetics diffuse across the neuronal lipophilic membrane in their uncharged (base) form, become re-ionized inside the axoplasm, and bind reversibly to specific receptor sites on the intracellular portion of voltage-gated sodium channels. This blocks sodium ion influx, preventing threshold depolarization and the generation and propagation of action potentials along the nerve fiber.

Question 49Surgical assessment, anatomy, bleeding, and complications

In surgical exodontia, dental elevators (botadores o elevadores) rely on fundamental mechanical principles. Which mechanical principle is applied when the straight elevator is inserted wedge-wise into the periodontal space between the alveolar bone wall and the tooth root?

  1. The wedge principle (Principio de la cuña) Correct answer.
  2. The pulley principle (Principio de la polea)
  3. The hydraulic ram principle
  4. The magnetic induction principle

Explanation

The straight elevator acts as a wedge (cuña) when its blade is forced into the periodontal ligament space between the root surface and the alveolar bone wall. This axial force drives the tooth occlusally along its long axis and expands the surrounding alveolar socket.

Question 50Surgical assessment, anatomy, bleeding, and complications

In the Pell and Gregory classification for impacted mandibular third molars, how is a tooth designated as 'Class II, Position B' anatomically described?

  1. Ample space between ramus and second molar; occlusal plane higher than adjacent second molar
  2. Space between ramus and second molar is completely absent; tooth completely submerged beneath bone
  3. The space between the anterior border of the ramus and the distal surface of the second molar is less than the mesiodistal diameter of the third molar crown (Class II); the occlusal surface is located between the occlusal plane and the cervical line of the second molar (Position B) Correct answer.
  4. The crown is located in the mandibular condyle with complete soft-tissue coverage

Explanation

In the Pell and Gregory classification: Class II means the space between the anterior border of the ramus and the distal surface of the second molar is less than the mesiodistal crown width of the third molar; Position B indicates the occlusal plane of the impacted tooth lies between the occlusal plane and the cervical line of the adjacent second molar.