ORE Part 1 flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

A-delta fibres

Myelinated, fast-conducting nerve fibres that mediate sharp, well-localised dental pain; they are activated by thermal and mechanical stimuli and by dentinal fluid movement.

C fibres

Unmyelinated, slow-conducting nerve fibres that mediate dull, poorly localised pain and are relatively resistant to local anaesthetics compared with A-delta fibres.

Parathyroid hormone action

Parathyroid hormone raises plasma calcium by increasing osteoclastic bone resorption, renal tubular calcium reabsorption and renal production of active vitamin D.

Osteoclast versus osteoblast

Osteoclasts are multinucleated cells that resorb bone; osteoblasts are mononuclear cells that synthesise osteoid, which later mineralises.

Local anaesthetic pKa

The pKa of a local anaesthetic determines the proportion of unionised base at tissue pH; acidic inflamed tissue reduces this fraction and lowers efficacy.

Resting salivary flow

Resting whole salivary flow is approximately 0.3-0.4 mL per minute, whereas stimulated flow rises to about 1.5-2.0 mL per minute.

Glass-ionomer cement

A dental cement that bonds chemically to enamel and dentine through polyalkenoic acid and releases fluoride over time; it is brittle and moisture-sensitive during setting.

Composite C-factor

The ratio of bonded to unbonded surface area in a cavity; a high C-factor increases polymerisation shrinkage stress and the risk of marginal debonding.

Enamel acid etching

Application of 37% phosphoric acid for 15-30 seconds removes surface hydroxyapatite and creates microporosities for resin tag formation and micromechanical retention.

Working length endodontics

The length from a coronal reference point to the apical constriction, conventionally set 0.5-1.0 mm short of the radiographic apex.

Sodium hypochlorite function

An endodontic irrigant that dissolves organic pulp tissue and has antimicrobial activity; it does not remove the inorganic smear layer, which requires EDTA.

Ante's law

The total root surface area of the abutment teeth must equal or exceed the root surface area of the teeth being replaced by a fixed prosthesis.

Ferrule effect

A 1.5-2.0 mm collar of parallel axial dentine around a post-retained restoration that improves resistance to fracture and retention.

BPE code 3

A BPE code of 3 means a probing depth of 3.5-5.5 mm; it indicates that a full periodontal assessment and charting are required.

Clinical attachment level

Clinical attachment level equals probing depth plus gingival recession, or probing depth minus gingival enlargement; it estimates historical attachment loss.

Dry socket

Alveolar osteitis presents 2-4 days after extraction with severe throbbing pain, an empty socket and no pus; it is managed by irrigation and dressing.

Infective endocarditis prophylaxis

NICE guidance does not recommend routine antibiotic prophylaxis before dental procedures to prevent infective endocarditis; exceptional high-risk cases may be discussed with a cardiologist.

Oro-antral communication

A connection between the oral cavity and maxillary sinus, most often after maxillary molar extraction; small defects may heal spontaneously but larger ones need closure.

Lidocaine maximum dose

Lidocaine with adrenaline has a maximum dose of about 4.4 mg/kg, with an absolute adult cap of 300 mg; dose must be calculated by body weight.

Oral SCC common sites

Oral squamous cell carcinoma most often affects the lateral border of the tongue and floor of the mouth, followed by the gingiva and buccal mucosa.

Leukoplakia definition

A predominantly white oral lesion that cannot be characterised clinically or pathologically as any other definable lesion; diagnosis is by exclusion.

Wickham striae

Fine white reticular lines seen in oral lichen planus, typically bilateral on the buccal mucosa; they represent hyperkeratosis along the epithelial surface.

Nikolsky sign

Sloughing of epithelium on gentle lateral pressure, seen in pemphigus vulgaris and other intraepithelial blistering diseases; it is usually negative in mucous membrane pemphigoid.

Ameloblastoma radiography

A multilocular soap-bubble radiolucency, usually in the posterior mandible; it is locally aggressive and has a high recurrence rate after conservative surgery.

Odontogenic keratocyst

A developmental odontogenic cyst with a thin lining, high recurrence rate and a scalloped radiolucent appearance; it may be associated with naevoid basal cell carcinoma syndrome.

Cone-beam CT dose

Cone-beam CT gives a lower radiation dose than multislice CT but a higher dose than a panoramic radiograph; dose varies widely with field of view and settings.

Primary tooth eruption

Primary teeth usually begin to erupt around 6 months, with mandibular central incisors first, and the full deciduous dentition of 20 teeth is complete by about 2.5-3 years.

Fluoride varnish concentration

Fluoride varnish contains 22,600 ppm fluoride (5% sodium fluoride) and is applied to caries-prone teeth, typically twice yearly in UK child programmes.

Angle Class I

In Angle Class I occlusion the mesiobuccal cusp of the upper first molar occludes in the buccal groove of the lower first molar.

IOTN components

The Index of Orthodontic Treatment Need combines a dental health component graded 1-5 with an aesthetic component graded 1-10.

DMFT index

DMFT counts decayed, missing due to caries and filled permanent teeth; dmft is the equivalent index for the primary dentition.

Fissure sealant indication

Sealants are indicated for deep pits and fissures in caries-prone teeth, especially first permanent molars, when the enamel is sound or only incipiently carious.