SDLE (SPLE Dentist) key terms

The basic structural unit of dental enamel: a tightly packed column of hydroxyapatite crystals running from the dentinoenamel junction toward the surface. Rods are roughly keyhole-shaped in cross-section, and their arrangement affects caries spread and acid-etching patterns.

A microscopic channel running through dentin from the pulp to the dentinoenamel or dentinocemental junction, containing the odontoblast process and dentinal fluid. Tubule density and diameter influence dentin permeability, sensitivity, and bonding.

The line where the crown's enamel meets the root's cementum. It may show enamel overlapping cementum, an edge-to-edge butt joint, or a gap exposing dentin, and this anatomy guides probing, scaling, and placement of restoration margins.

The fibrous connective tissue between root cementum and the alveolar bone socket. It anchors the tooth, cushions occlusal forces, carries blood vessels and nerves, and permits proprioception and the limited tooth movement exploited in orthodontics.

A thin, nonkeratinized band of epithelial cells attached to the tooth surface at the base of the gingival sulcus. It forms the soft-tissue seal against the oral environment, and its apical migration marks the beginning of attachment loss.

A structured community of bacteria embedded in a self-produced polysaccharide matrix that adheres to teeth and restorations. Its acids cause caries, and its proximity to the gingival margin drives gingivitis and periodontitis.

A gram-positive, facultative anaerobic coccus that colonizes tooth surfaces, ferments sucrose into lactic acid, and builds sticky glucans. It is a principal cariogenic organism linked to the initiation of fissure and smooth-surface caries.

A graph of plaque pH after a sugar rinse, showing a rapid fall to around pH 5 followed by a slower return to resting pH over roughly 20 to 60 minutes. Frequent sugar exposures flatten recovery and prolong demineralization.

The plaque or oral fluid pH at which mineral is no longer saturated and tooth tissue begins to dissolve, about 5.5 for enamel and 6.0 to 6.5 for root dentin. Below this value, demineralization outpaces remineralization.

A concentrated fluoride lacquer, usually 5 percent sodium fluoride near 22,600 ppm, painted onto tooth surfaces. It clings to enamel and releases fluoride slowly, reducing demineralization and arresting early lesions in high-risk patients and children.

Caries Management by Risk Assessment: a structured clinical protocol that sorts a patient's caries risk from disease indicators and risk factors, then assigns preventive and restorative care matched to that risk level.

A resin or glass ionomer coating placed into occlusal and other fissured surfaces to block biofilm retention in grooves. It prevents caries when applied to sound pits or to early, noncavitated lesions.

A thin layer of ground tooth debris, denatured collagen, and bacteria created on dentin and enamel by cutting instruments. It lowers dentin permeability but interferes with bonding unless removed or chemically modified.

The interdiffusion zone formed when resin infiltrates acid-demineralized dentin and polymerizes around exposed collagen fibrils. Its quality, set by etching, priming, and adhesive infiltration, largely governs dentin bond strength and durability.

Volume reduction occurring as resin monomers link into polymer chains during curing of composites and other resins. Constrained by the bond to cavity walls, it generates stress that can cause marginal gaps, microleakage, and postoperative sensitivity.

A water-based impression material, commonly alginate, that sets by reaction between soluble alginate and calcium ions. It is inexpensive and simple for study casts and provisional work, but it is dimensionally unstable after setting.

The distance from a coronal reference point to the chosen apical limit of instrumentation, usually the apical constriction or 0.5 to 1 mm short of the radiographic apex. It guides cleaning and filling to avoid under- or overextension.

The narrowest part of the root canal near the apical foramen, where canal space meets periodontal tissue. It is the preferred biologic endpoint for instrumentation and obturation because filling short of it protects the periapical tissues.

The most widely used root canal irrigant; it dissolves necrotic tissue and collagen and kills most canal microorganisms. It is used at 0.5 to 5.25 percent with careful isolation, because extrusion causes severe tissue injury.

A natural trans-polyisoprene polymer used with sealer as the standard core material for obturating root canals. It is thermoplastic, biocompatible, and radio-opaque, but it does not bond to dentin and must be well compacted.

The distance from the cementoenamel junction to the base of the periodontal pocket, showing how much supporting tissue has been destroyed. Measured by probing, it is a key criterion for grading periodontitis severity and progression.

A direct structural and functional union between living bone and the surface of a loaded implant, with no intervening soft tissue. It depends on a biocompatible surface, atraumatic surgery, and undisturbed healing.

A maxillomandibular relationship in which the condyles rest in their most anterior-superior position against the articular eminences with the discs properly interposed. It is a reproducible reference for dentures, splints, and full-mouth rehabilitation.

The maxillomandibular separation, usually recorded as facial or incisal height, when the teeth are in maximum intercuspation. It guides complete denture construction and the restoration of worn or collapsed dentitions.

An occlusal scheme, chiefly for complete dentures, in which contacts occur simultaneously on both sides and in anterior and posterior regions during eccentric movements. It stabilizes the prostheses and reduces tipping forces.

A foundation, cast or prefabricated, placed in a prepared root canal to retain a crown when little coronal tooth structure remains. The post holds the core; it does not strengthen the root, and adequate ferrule is required.

A mandibular local anesthesia technique that deposits solution near the mandibular foramen to anesthetize the inferior alveolar nerve, usually along with the lingual nerve. It gives profound pulpal anesthesia for mandibular molars and premolars.

Also called dry socket: severe throbbing pain from a healing extraction socket after the blood clot is lost, leaving bone exposed. It occurs mainly after mandibular molar removal and is managed by irrigation and dressing rather than antibiotics alone.

Exposed maxillofacial bone persisting beyond eight weeks in a patient taking antiresorptive or antiangiogenic drugs, with no head and neck radiotherapy history. It is often triggered by extraction and is best managed by prevention.

A system that classifies malocclusion by the anteroposterior relationship of the first permanent molars: Class I normal, Class II with the mandible relatively retruded, Class III with it relatively protruded. It guides diagnosis and treatment planning.

The difference in mesiodistal width between the primary canine and molars and their permanent successors in the same arch, roughly 1.5 mm per side in the mandible. It is often used to relieve mild crowding during the transition.

A cephalometric angle formed by points A, N, and B, equivalent to SNA minus SNB, that expresses the anteroposterior skeletal relation of maxilla to mandible. A value near 2 degrees is normal; larger suggests Class II and smaller Class III.

An intraoral film or sensor that shows the crowns of maxillary and mandibular posterior teeth together with the alveolar crest on one image. It is the preferred view for interproximal caries and early bone loss.

As Low As Reasonably Achievable: the radiation protection principle that every exposure should be kept to the minimum needed for diagnosis. It drives collimation, fast receptors, and avoidance of unnecessary retakes.

The most common odontogenic cyst, arising from epithelial rests of Malassez within a periapical granuloma of a nonvital tooth. It appears as a well-defined radiolucency at the apex and usually resolves after root canal treatment or extraction.

A predominantly white patch of oral mucosa that cannot be scraped off and cannot be diagnosed as any other lesion. It is a clinical label with malignant transformation potential, so biopsy and follow-up are advised.

A patient's voluntary agreement to a procedure after being told its nature, purpose, risks, benefits, alternatives, and the consequences of refusal. It must be documented and obtained from someone legally competent to give it.

A legal doctrine meaning the thing speaks for itself, allowing negligence to be inferred when an injury would not ordinarily happen without negligence and the dentist controlled the instrument or technique involved.