DOH Dentist Exam cheat sheet

Enamel is 96% mineral by weight, primarily hydroxyapatite; its organic matrix is mostly amelogenin and enamelin.

Dentin is 70% mineral, 20% organic (mostly type I collagen), and 10% water; dentinal tubules converge toward the pulp at ~2.5:1 ratio.

Pulp pressure is approximately 10–20 mmHg; pulpal blood flow is about 0.5 mL/min/g, among the highest in the body.

Periodontal ligament width ranges from 0.15–0.38 mm, narrowest in the middle third; it contains principal fibers (alveologingival, dentogingival, dentoperiosteal, transseptal, alveolar crest, horizontal, oblique, apical, interradicular).

Gingival crevicular fluid flow increases with inflammation; its volume is measured by Periotron.

Saliva flow: unstimulated 0.3–0.4 mL/min, stimulated 1.5–2.0 mL/min; pH 6.7–7.4; main buffer is bicarbonate.

Caries requires three factors: susceptible host, cariogenic flora (mutans streptococci, lactobacilli), and fermentable carbohydrate over time.

Bacterial plaque biofilm formation: pellicle → initial colonizers (Streptococcus sanguinis, Actinomyces) → secondary colonizers (Fusobacterium, Porphyromonas) → mature complex.

Maxillary first molar has three roots (MB, DB, palatal) and typically four canals (MB1, MB2, DB, palatal); mandibular first molar has two roots and three canals (MB, ML, distal).

Cavity preparation nomenclature: Class I occlusal pits/fissures; Class II proximal of posterior teeth; Class III proximal of anterior teeth; Class IV includes incisal angle; Class V gingival third; Class VI incisal edge tip.

Tooth preparation for amalgam requires 0.5 mm beyond enamel-dentin junction for caries removal and 1.5–2 mm pulpal floor depth for strength.

Composite resin polymerization shrinkage: 2–3% for methacrylate-based; shrinkage stress reduced by incremental layering ≤2 mm, soft-start curing, and low C-factor.

Bonding: total-etch uses 35% phosphoric acid (15 s dentin, 30 s enamel); self-etch uses acidic monomers; ethanol wet-bonding improves resin infiltration.

Working length in endodontics is determined by apex locator and confirmed radiographically 0.5–1.0 mm short of the radiographic apex.

Irrigants: NaOCl 0.5–5.25% dissolves organic tissue and is antimicrobial; EDTA 17% removes smear layer; chlorhexidine 2% is final rinse alternative but precipitates with NaOCl.

Root canal preparation: crown-down technique, apical enlargement to at least size 25–30 with taper 0.04–0.06; patency file maintained.

Obturation: gutta-percha with sealer; warm vertical compaction achieves 3D fill; apical seal should be 0.5–1 mm from radiographic apex.

Post-endodontic restoration: anterior teeth with minimal loss may use composite; posterior teeth need cuspal coverage (onlay/crown) when marginal ridges or cusps are compromised.

Third molar extraction difficulty assessed by Pell-Gregory classification (depth and ramus relationship) and Winter's classification (angulation: mesioangular, horizontal, vertical, distoangular).

Local anesthesia: maxillary infiltration 1.8 mL of 2% lidocaine with 1:100,000 epinephrine; mandibular block (inferior alveolar nerve) 1.5–1.8 mL; maximum safe dose lidocaine 4.4 mg/kg (7 mg/kg with epinephrine).

Post-extraction bleeding management: pressure pack, tranexamic acid mouthwash, suturing, and hemostatic agents (gelatin sponge, oxidized cellulose).

Dry socket (alveolar osteitis) presents 2–4 days post-extraction with severe pain and empty socket; treatment is irrigation and medicated dressing (eugenol-based).

Oral potentially malignant disorders: leukoplakia, erythroplakia, oral submucous fibrosis, lichen planus; erythroplakia has highest malignant transformation rate.

Oral cancer red flags: non-healing ulcer >2 weeks, induration, fixation, lymphadenopathy, paresthesia; most common site is lateral border of tongue and floor of mouth.

Trigeminal neuralgia: paroxysmal sharp pain in V2/V3 distribution, triggered by touch; first-line carbamazepine.

Odontogenic infections spread along fascial planes; Ludwig's angina involves submandibular, sublingual, and submental spaces bilaterally and is a surgical emergency.

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) defined by >8 weeks exposed bone in patients on antiresorptives; risk higher with IV zoledronic acid.

Gingival index (Löe-Silness) scores 0–3; plaque index (Silness-Löe) scores 0–3; bleeding on probing indicates active inflammation.

Periodontal probing depth ≤3 mm is healthy; ≥4 mm with bleeding indicates periodontitis; clinical attachment loss = probing depth + recession (or − hyperplasia).

2017 AAP/EFP classification: Stage I–IV based on severity and complexity; Grade A–C based on progression rate (bone loss/age ratio).

Scaling and root planing (SRP) is definitive for Stage I–II; Stage III–IV may require surgery; re-evaluation at 6–8 weeks.

Risk factors: smoking (dose-dependent), diabetes (HbA1c >7%), poor plaque control, genetic predisposition (IL-1 polymorphism), stress, medications.

Necrotizing periodontal diseases: necrotizing gingivitis (NG) and periodontitis (NP) with punched-out papillae, pseudomembrane, fetor oris; associated with immunosuppression and stress.

Peri-implant mucositis: bleeding on probing without bone loss; peri-implantitis: bleeding + bone loss ≥0.5 mm/year; risk factors include plaque, smoking, history of periodontitis.

Maintenance: supportive periodontal therapy every 3–6 months for periodontitis patients; recall interval based on risk profile.

Local delivery of antibiotics (e.g., minocycline microspheres) is adjunctive, not primary therapy; systemic antibiotics (amoxicillin + metronidazole) may be used for aggressive/necrotizing cases.

Complete denture: primary impression with irreversible hydrocolloid, final with elastomeric; border molding with modeling compound; posterior palatal seal provides retention.

Balanced occlusion in complete dentures: bilateral simultaneous contacts in centric and eccentric movements; lingualized occlusion may improve stability.

Fixed partial denture (FPD) abutment selection: crown-root ratio ≥1:1, periodontal surface area (Ante's law), alignment, and endodontic status.

Removable partial denture (RPD) components: major connector, minor connector, rests, direct retainers (clasps), indirect retainers, denture base.

Kennedy classification: Class I bilateral edentulous posterior; Class II unilateral posterior; Class III unilateral bounded posterior; Class IV anterior single edentulous space.

Implant success criteria (Albrektsson): no mobility, no radiolucency, bone loss <0.2 mm/year after first year, no pain/infection, function ≥5 years.

Implant loading: immediate (within 1 week), early (1 week–2 months), conventional (>2 months); immediate loading requires primary stability (torque ≥35 Ncm).

Occlusal scheme for implant-supported restorations: mutually protected occlusion, light contacts in centric, no working/non-working interferences.

Denture stomatitis: Candida albicans associated; treatment includes denture hygiene, antifungal (nystatin, miconazole), and removal at night.

Angle classification: Class I normal molar relationship; Class II mesiobuccal cusp of maxillary first molar mesial to buccal groove of mandibular first molar; Class III distal.

Cephalometric landmarks: SNA (maxillary position), SNB (mandibular position), ANB (skeletal relationship); normal SNA ~82°, SNB ~80°, ANB ~2°.

Growth modification: functional appliances (Twin Block, Herbst) for Class II; facemask for Class III; rapid maxillary expansion for transverse deficiency.

Eruption timeline: primary teeth 6 months–2.5 years; permanent first molar 6 years, central incisor 6–7 years, canine 11–12 years, second molar 12–13 years, third molar 17–21 years.

Pediatric behavior management: tell-show-do, positive reinforcement, distraction; avoid restraint unless emergency.

Caries risk assessment in children: diet, fluoride exposure, plaque, salivary flow, history of caries; anticipatory guidance at each visit.

Fluoride varnish (5% NaF) application every 3–6 months for high-risk children; systemic fluoride supplementation based on water fluoride concentration.

Pulpotomy in primary molars: formocresol or ferric sulfate; pulpectomy for irreversible pulpitis; stainless steel crown for extensive decay.

Space maintenance: band and loop for single tooth loss; transpalatal arch or Nance for multiple; space regain with fixed or removable appliances.

DMFT index: Decayed, Missing, Filled Teeth; dmft for primary dentition; DMFS for surfaces; higher score indicates greater caries experience.

Community Periodontal Index (CPI) scores 0–4; score 3 = pocket 4–5 mm; score 4 = pocket ≥6 mm.

Water fluoridation optimal level: 0.7–1.2 ppm depending on climate; reduces caries by 20–40%; fluorosis risk if >2 ppm.

Study designs: cross-sectional (prevalence), case-control (odds ratio), cohort (relative risk), randomized controlled trial (cause-effect).

Sensitivity = true positives / (true positives + false negatives); specificity = true negatives / (true negatives + false positives).

Ethical principles: autonomy, beneficence, nonmaleficence, justice; informed consent requires capacity, disclosure, understanding, voluntariness.

HIPAA Privacy Rule protects patient health information; breach notification required within 60 days; minimum necessary standard applies.

Mandatory reporting: child abuse, elder abuse, certain communicable diseases (e.g., tuberculosis, syphilis) per state law; HIV reporting varies.

Scope of practice: dentist must not delegate procedures requiring professional judgment (diagnosis, treatment planning, surgery) to auxiliary personnel.