MDCN Dental Assessment cheat sheet

Pulpitis is classified as reversible (provoked pain, no spontaneous pain, vital pulp responsive to cold) or irreversible (spontaneous or nocturnal pain, lingering response, or nonresponsive necrotic pulp).

Pulp testing: cold test (ethyl chloride or refrigerant spray) assesses A-delta fibres; electric pulp testing assesses A-delta fibres but gives false negatives in immature or calcified teeth; percussion and palpation assess apical periodontitis.

Luxation injuries: concussion needs no splint; subluxation and extrusion need flexible splint 2 weeks; lateral luxation needs flexible splint 4 weeks; avulsion needs flexible splint 2 weeks plus replantation within 60 minutes for best prognosis.

Avulsed permanent tooth storage: milk, saline, or Hank balanced salt solution; do not handle root surface; if extraoral dry time exceeds 60 minutes, replantation prognosis is poor and replacement resorption (ankylosis) is likely.

Local anaesthetic maximum doses: lidocaine 2% with 1:100,000 adrenaline 4.4 mg/kg (max 500 mg); articaine 4% 7 mg/kg (max 500 mg); prilocaine 3% 6 mg/kg (max 400 mg); mepivacaine 3% 6.6 mg/kg (max 400 mg).

Inferior alveolar nerve block failure is most often due to accessory innervation (mylohyoid nerve, contralateral fibres) or anatomical variation; Gow-Gates or Vazirani-Akinosi techniques are alternatives.

Dry socket (alveolar osteitis) presents 2-4 days post-extraction with severe throbbing pain, empty socket, and exposed bone; risk factors include smoking, oral contraceptives, and traumatic extraction.

Antibiotic prophylaxis for infective endocarditis is indicated for high-risk cardiac conditions (prosthetic valve, previous endocarditis, certain congenital heart disease) before invasive dental procedures; regimen is amoxicillin 2 g orally 30-60 minutes pre-procedure.

Odontogenic infection spread: mandibular molars drain to submandibular and sublingual spaces; maxillary canines to canine fossa; danger spaces include sublingual, submandibular, and lateral pharyngeal spaces requiring urgent referral.

Le Fort I fracture: horizontal fracture through maxilla above apices, mobile maxilla, guérin sign (ecchymosis of palate), and malocclusion; Le Fort II is pyramidal; Le Fort III is craniofacial disjunction.

Mandibular fracture management: single favourable fractures may be treated closed with arch bars and intermaxillary fixation; displaced or unfavourable fractures require open reduction and internal fixation (ORIF) with miniplates.

Zygomatic complex fracture signs: subconjunctival haemorrhage, diplopia, infraorbital paraesthesia, flattened malar prominence, and trismus; orbital floor involvement needs assessment for entrapment.

TMJ dislocation: condyle anterior to articular eminence; reduce with downward and backward pressure on mandible; recurrent dislocation may need eminectomy or botulinum toxin.

Third molar assessment: Pell and Gregory classification (depth and ramus relationship) and Winter classification (angulation) guide difficulty; inferior alveolar nerve proximity assessed with cone beam CT if roots overlap canal.

Orthognathic surgery: Le Fort I osteotomy for maxillary repositioning; bilateral sagittal split osteotomy (BSSO) for mandibular advancement or setback; genioplasty for chin position.

Osteoradionecrosis risk: dose >60 Gy, extraction post-radiotherapy, poor oral hygiene; hyperbaric oxygen controversial; avoid elective extractions for 3 years post-radiotherapy where possible.

MRONJ (medication-related osteonecrosis of the jaw): associated with bisphosphonates, denosumab, and antiangiogenics; staged 0-3; conservative management with chlorhexidine and antibiotics; surgery reserved for stage 3.

Salivary gland tumours: pleomorphic adenoma most common benign; mucoepidermoid carcinoma most common malignant; superficial parotidectomy with facial nerve preservation for benign parotid tumours.

Tooth preparation for full veneer metal crown: occlusal reduction 1.5-2.0 mm, axial reduction 1.0-1.5 mm, and a chamfer or shoulder margin of 1.0 mm; ceramic crowns need 1.5-2.0 mm occlusal and 1.0-1.5 mm axial reduction.

Minimum ceramic thickness for strength: lithium disilicate 1.0-1.5 mm; zirconia 0.5-1.0 mm; feldspathic veneers 0.3-0.5 mm; resin-bonded bridges need retainer thickness of 0.5-0.7 mm.

Composite resin bonding: total-etch (37% phosphoric acid) for enamel, self-etch for dentine to reduce postoperative sensitivity; C-factor and polymerisation shrinkage cause marginal leakage in class I and V cavities.

Caries removal: selective caries removal to soft dentine in deep lesions (stepwise excavation) reduces pulp exposure; complete removal to hard dentine in shallow lesions; use caries detection dyes cautiously as they stain sound dentine.

Post and core: retain at least 4-5 mm of apical gutta-percha; post length at least equal to crown height; ferrule of 1.5-2.0 mm of circumferential dentine improves fracture resistance.

Endodontic working length: determined with apex locator and confirmed radiographically; apical limit is 0.5-1.0 mm short of radiographic apex; master cone fit should show tug-back at working length.

Root canal irrigation: sodium hypochlorite 1-5.25% dissolves organic tissue and is antimicrobial; EDTA 17% removes smear layer; do not extrude irrigant beyond apical foramen due to risk of sodium hypochlorite accident.

Removable partial denture design: rest seats on abutment teeth, major connector (lingual bar or palatal plate), and clasps for retention; avoid soft tissue coverage where possible to reduce plaque accumulation.

DMFT index: sum of decayed, missing, and filled permanent teeth per individual; dmft is the equivalent for primary teeth; DMFS counts surfaces.

Caries prevalence measured by DMFT at age 12 is the WHO global indicator; WHO goal is DMFT <3 at age 12; water fluoridation at 1 ppm reduces caries by 20-40%.

Community Periodontal Index (CPI) scores sextants 0-4; score 0 healthy, 1 bleeding, 2 calculus, 3 pocket 4-5 mm, 4 pocket ≥6 mm; used in WHO Oral Health Surveys.

Fluoride varnish 22,600 ppm applied 2-4 times yearly is effective for caries prevention in children; fluoride toothpaste 1,000-1,500 ppm is standard for adults and children over 3 years.

Oral health promotion: Ottawa Charter principles (build healthy public policy, create supportive environments, strengthen community action, develop personal skills, reorient health services) underpin community programmes.

Screening and prevention: fissure sealants reduce caries in permanent molars by up to 80% when applied on erupting teeth; recall interval individualised by risk assessment.

Dental workforce planning: skill mix includes dentists, therapists, hygienists, and clinical dental technicians; community programmes target high-risk groups such as children in deprived areas and older people in care homes.

Sugar consumption: WHO recommends free sugars <10% of energy intake, ideally <5%; sugar-sweetened beverage taxation is a population-level prevention measure.

Epidemiology: cross-sectional surveys measure prevalence; cohort studies measure incidence; randomised controlled trials provide highest evidence for interventions; CONSORT and STROBE guide reporting.