Module 3 — Dental Pathology + Oral Health and Nutrition

What is dental caries, and which two bacterial groups are emphasized as causes?

Dental caries (tooth decay) is a biofilm-mediated disease involving mineral loss from teeth. The slides emphasize mutans streptococci, especially Streptococcus mutans (MS), and lactobacilli (LB).

What roles do mutans streptococci and lactobacilli play in dental caries?

Mutans streptococci are disease-producing bacteria found in plaque; lactobacilli are associated with carbohydrate exposure and the progression of decay.

What is oral biofilm (dental plaque)?

A soft, sticky community of microorganisms adhering to teeth, restorations, appliances, oral mucosa, and other surfaces. It can contribute to caries and periodontal inflammation.

What is the acquired pellicle, and how is it associated with plaque?

The pellicle is a thin coating on tooth surfaces to which bacteria can attach, allowing dental biofilm to develop and accumulate.

What is enamel made of, and why is it important?

Enamel is the body's most highly mineralized tissue, consisting largely of hydroxyapatite crystals arranged into rods or prisms. Its mineral content makes it harder than bone.

What three factors are required for the caries process described in the slides?

A susceptible tooth, cariogenic bacteria, and fermentable carbohydrates such as sugars or cooked starches.

How do fermentable carbohydrates cause dental caries?

Plaque bacteria metabolize sugars and starches, producing acids that dissolve calcium and phosphate from the tooth, gradually damaging enamel.

Why does frequent snacking on sugary or starchy foods increase caries risk?

Every exposure allows bacteria to produce acids. Frequent exposure creates repeated periods of demineralization with less opportunity for remineralization.

What are demineralization and remineralization?

Demineralization is the loss of calcium and phosphate from tooth structure; remineralization is the redeposition of these minerals into previously weakened areas.

Why is dental caries considered a dynamic process?

Teeth undergo repeated cycles of demineralization and remineralization. A lesion develops when mineral loss exceeds mineral replacement over time.

What is the difference between incipient and overt (frank) caries?

Incipient caries is early enamel demineralization without cavitation; overt or frank caries involves cavitation, meaning a visible or detectable hole.

What is rampant caries?

Rapid, widespread development of multiple carious lesions throughout the mouth, sometimes progressing quickly from early lesions to cavitation.

What are the four main locations or types of dental caries?

Pit-and-fissure caries, smooth-surface caries, root-surface caries, and secondary or recurrent caries.

Where does pit-and-fissure caries commonly develop?

In occlusal pits and fissures, buccal or lingual grooves of posterior teeth, and lingual pits of maxillary incisors.

Where does smooth-surface caries develop?

On relatively smooth enamel surfaces, including mesial, distal, facial, and lingual tooth surfaces.

What is root-surface caries, and why are older adults more susceptible?

Decay on exposed tooth roots, often following gingival recession. Cementum is less mineralized and more soluble than enamel, making exposed roots more vulnerable.

What is secondary or recurrent caries?

New decay developing around an existing restoration, often where small gaps permit bacterial accumulation and microleakage.

What is early childhood caries (ECC)?

Tooth decay affecting young children, sometimes called baby-bottle tooth decay in the slides. It can cause pain, infection, and extensive destruction of primary teeth.

What factors increase the risk of early childhood caries?

Frequent sugary foods or drinks, sleeping with a bottle containing cariogenic liquids, limited access to dental care, inadequate fluoride exposure, and difficulties maintaining oral hygiene.

How can caregivers help prevent early childhood caries?

Maintain their own oral health, provide appropriate oral hygiene for the child, limit frequent sugary or sticky snacks, avoid prolonged exposure to sweetened bottles, and obtain preventive dental care.

What are the three major protective functions of saliva?

Physical cleansing that removes debris; chemical protection through calcium, phosphate, and fluoride for remineralization; and antibacterial protection involving substances such as immunoglobulins.

Why does reduced salivary flow increase dental caries risk?

Less saliva means less cleansing, reduced buffering and mineral availability, and weaker protection against bacterial activity.

What are the main methods used to detect dental caries?

Visual examination, dental explorers, radiographs, indicator dyes, electronic or optical detection devices, and laser-based caries detectors.

What is a limitation of detecting caries with a sharp dental explorer?

A sticky feeling may suggest decay, but the technique can be unreliable for early occlusal lesions and does not independently confirm caries.

What are the advantages and limitations of radiographs in detecting caries?

Radiographs are valuable for interproximal decay, but early occlusal lesions may not be visible and the true extent of decay may be greater than it appears.

What visual findings may suggest dental caries?

Dark grooves or gray shadows beneath enamel may suggest decay, but staining alone is not enough to establish a diagnosis.

What are caries indicator dyes used for?

They are applied during cavity preparation to help identify remaining caries-affected tissue through changes in coloration.

What are the advantages and limitations of laser-based caries detection in the slides?

It can help reveal bacterial activity or changes beneath enamel, but the device discussed cannot reliably detect interproximal or subgingival caries or decay beneath restorations.

What does CAMBRA stand for, and what is its goal?

Caries Management by Risk Assessment. It evaluates disease risk and protective factors so prevention and treatment can be individualized.

What four caries-risk categories are used in CAMBRA?

Low, moderate, high, and extreme risk.

What are four major ways to prevent or interrupt the caries process?

Use fluoride, consider appropriate antibacterial rinses, reduce exposure to fermentable carbohydrates, and improve salivary flow.

Why does filling a cavity not necessarily eliminate a patient's risk of further decay?

A restoration repairs damaged tooth structure but does not automatically remove the underlying causes, including bacterial plaque, dietary habits, and insufficient protective factors.

What are examples of caries risk-assessment tests?

Tests measuring mutans streptococci or lactobacilli in saliva, salivary flow-rate testing, and the one-minute chairside CariScreen bacterial test mentioned in the slides.

What is the periodontium?

The tissues supporting and surrounding the teeth, including gingiva, periodontal ligament, cementum, and alveolar bone.

What is periodontal disease?

An inflammatory disease affecting the tissues supporting the teeth; advanced disease can destroy connective-tissue attachment and alveolar bone.

What systemic conditions are associated with periodontal disease in the presentation?

Coronary artery disease, diabetes, stroke, and preterm or low-birth-weight delivery. These are described as associations and risk relationships, not proof that one disease directly causes another.

How are preterm birth and low birth weight defined in the slides?

Preterm birth occurs before 37 weeks of pregnancy; low birth weight means less than approximately 5.5 lb (2.5 kg).

How does oral biofilm contribute to periodontal disease?

Bacteria in plaque initiate inflammation. Disease risk is influenced by the bacterial species, duration of plaque accumulation, and the patient's response.

What is dental calculus (tartar)?

Hardened mineralized plaque containing calcium and phosphate salts. Its rough, porous surface encourages additional bacterial plaque accumulation.

What is the difference between supragingival and subgingival calculus?

Supragingival calculus forms above the gingival margin and is often yellow-white; subgingival calculus forms beneath the gingival margin, sometimes inside periodontal pockets, and may appear dark green or black.

What are common signs and symptoms of periodontal disease?

Red, swollen, tender or bleeding gingiva; loose or separating teeth; pain while chewing; and possible pus near teeth or gingival tissues.

How do gingivitis and periodontitis differ?

Gingivitis is inflammation limited to gingival tissues without loss of tooth-supporting attachment; periodontitis extends into supporting tissues and can destroy periodontal attachment and alveolar bone.

What is a periodontal pocket?

A pathologically deepened space between tooth and gingival tissues associated with loss of supporting attachment in periodontitis.

What is dental perioscopy?

Use of a magnifying visualization system to examine subgingival root surfaces, detect remaining calculus, and sometimes identify cracks or early root decay. The slides mention magnification up to 46 times.

What is oral pathology, and why should dental assistants understand it?

Oral pathology studies diseases of the mouth. Dental assistants must recognize abnormal findings, collect relevant information, and help the dentist arrange appropriate evaluation.

What types of patient history help diagnose oral lesions?

Personal, family, medical, and dental history, plus the history of the lesion, including symptoms, duration, and changes over time.

What is a clinical diagnosis?

A diagnosis based on examination findings such as a lesion's colour, shape, size, location, surface appearance, and other observable characteristics.

What is a radiographic diagnosis, and what conditions can it reveal?

Diagnosis supported by imaging of oral structures, including periapical pathology, internal resorption, and impacted teeth.

What is microscopic diagnosis, and how is a biopsy used?

A biopsy removes tissue from a suspicious lesion so a pathology laboratory can examine it microscopically, often providing a definitive diagnosis.

What is a laboratory diagnosis?

A diagnosis informed by tests of samples such as blood, urine, secretions, tissue, or microbial cultures.

What is therapeutic diagnosis?

Using a patient's response to a treatment as part of the diagnostic process; the slides use angular cheilitis caused by vitamin deficiency versus fungal infection as an example.

What are surgical and differential diagnoses?

Surgical diagnosis uses findings observed during a procedure; differential diagnosis compares possible causes and uses tests to rule out alternatives.

How do acute and chronic inflammation differ?

Acute inflammation develops over a short period after injury or irritation; chronic inflammation continues because the irritation or disease process persists.

What is an oral lesion?

Any abnormal change or damage involving oral tissue, including sores, growths, discolouration, ulcers, and other tissue abnormalities.

How do an ulcer and an erosion differ?

An ulcer is a deeper break in oral mucosa, often crater-like; an erosion is a more superficial loss or injury involving the mucosal surface.

How do an abscess and a cyst differ?

An abscess is a localized collection of pus associated with infection; a cyst is a pathological sac that may contain fluid or semisolid material and is not necessarily infected.

How do a vesicle, pustule, and hematoma differ?

Vesicle: fluid-filled blister; pustule: pus-filled lesion; hematoma: localized collection of blood. Oral vesicles often rupture and leave ulcers.

What is the difference between an oral plaque lesion and dental plaque?

An oral plaque lesion is a slightly raised patch of abnormal tissue; dental plaque is microbial biofilm adhering to oral surfaces.

What is an ecchymosis?

A flat area of discoloration caused by bleeding into tissue, commonly called a bruise.

What are nodules, granulomas, and neoplasms?

Nodule: small, solid, rounded lump; granuloma: localized growth or inflammatory tissue mass; neoplasm: abnormal tissue growth that may be benign or malignant.

What is leukoplakia?

A persistent white patch or plaque in the mouth that cannot be scraped away and requires evaluation to determine its nature or possible precancerous changes.

What is oral lichen planus, and what are Wickham's striae?

A chronic inflammatory condition affecting oral mucosa and sometimes skin; Wickham's striae are characteristic interconnecting white lines or lace-like markings.

What is oral candidiasis, and which fungus commonly causes it?

An oral fungal infection commonly caused by Candida albicans, especially in people with altered oral flora or compromised immune function.

What factors increase the risk of oral candidiasis?

Antibiotic therapy, diabetes, xerostomia (dry mouth), immune suppression, and HIV-related immunodeficiency.

What are recurrent aphthous ulcers (canker sores)?

Painful recurring ulcers of oral mucosa. The slides distinguish smaller, faster-healing minor ulcers from larger, deeper, longer-lasting major ulcers.

How do minor and major recurrent aphthous ulcers differ in the presentation?

Minor ulcers account for most cases and usually heal within 7–10 days; major ulcers are larger, deeper, and take longer to heal.

What is oral cellulitis?

A spreading inflammation or infection of soft tissue that can develop from an oral infection such as a dental abscess and may cause rapidly increasing swelling.

What are glossitis, black hairy tongue, geographic tongue, and fissured tongue?

Glossitis: tongue inflammation; black hairy tongue: elongated filiform papillae; geographic tongue: irregular smooth patches from papillae loss; fissured tongue: deep grooves, usually a normal variation.

What oral findings may be associated with vitamin B12 deficiency or pernicious anemia?

A sore or inflamed tongue, anemia, pallor, weakness, and fatigue. Pernicious anemia involves impaired vitamin B12 absorption.

Why can oral cancer be difficult to detect early?

Early lesions may be painless and therefore overlooked. Abnormal persistent lesions still require professional evaluation.

How do carcinoma, adenocarcinoma, sarcoma, and osteosarcoma differ?

Carcinoma: malignant epithelial tumour; adenocarcinoma: malignant glandular tumour; sarcoma: malignant connective-tissue tumour; osteosarcoma: malignant bone tumour.

What is metastasis in oral cancer?

The spread of malignant cells from the original tumour to other regions, including cervical lymph nodes in the neck.

What oral symptoms may occur with leukemia?

Gingival bleeding, ulceration, swelling or enlargement, spongy gingiva, and unusual reddish or magenta gingival coloration.

Why do people with advanced HIV infection develop characteristic oral lesions?

HIV can impair immune function, especially through depletion of CD4 T-helper cells, increasing susceptibility to opportunistic infections and some malignancies.

What oral manifestations associated with HIV/AIDS are emphasized in the slides?

Linear gingival erythema (HIV-associated gingivitis), severe periodontal lesions, cervical lymphadenopathy, candidiasis, and lymphoma.

What is HIV-associated gingivitis or linear gingival erythema?

A prominent bright-red line along the gingival margin, sometimes extending over attached gingiva and accompanied by small pinpoint bleeding areas.

What is cervical lymphadenopathy?

Enlargement or disease of lymph nodes in the neck; it may accompany HIV and many other systemic or local conditions.

What is an opportunistic infection?

An infection caused by organisms that are more likely to produce significant disease when the immune system is weakened.

How do inherited, developmental, and congenital disorders differ?

Inherited disorders are transmitted through genes; developmental disorders arise during growth and formation; congenital disorders are present at birth and may be genetic or developmental.

What is the goal of preventive dentistry?

To help individuals maintain optimal oral health by preventing disease through home hygiene, fluoride, nutrition, dental examinations, cleaning, and timely treatment.

What is the main purpose of plaque-disclosing agents?

To temporarily stain plaque red, blue, or purple so patients can see areas missed during brushing and flossing.

What types of plaque-disclosing agents are described in the slides?

Chewable tablets, liquids, applicators or swabs, and fluorescent agents; some products distinguish newer and older plaque with different colours.

What is a dentifrice, and what ingredients may it contain?

A toothpaste or other cleaning preparation containing mild abrasives and often fluoride; additional ingredients may address sensitivity, gingivitis, tartar, or bad breath.

What is the ADA Seal of Acceptance?

A designation awarded after scientific review of a dental product by the American Dental Association's Council on Scientific Affairs.

Why should toothpaste with excessive abrasiveness be avoided?

Repeated use of highly abrasive dentifrices may damage tooth surfaces, even though mild abrasives help remove surface stains.

Why should mouth rinses not replace brushing and flossing?

Rinses may freshen breath, loosen debris, or reduce microorganisms, but they do not replace mechanical cleaning of tooth surfaces and interproximal areas.

How can chewing gum help protect oral health?

Chewing stimulates saliva, which helps neutralize plaque acids and clear food debris. The presentation illustrates xylitol-containing gum.

Why is interdental cleaning needed in addition to toothbrushing?

A toothbrush generally cleans the facial, lingual, and chewing surfaces but cannot effectively reach all mesial and distal surfaces between adjacent teeth.

What are interproximal brushes and dental stimulators used for?

Interproximal brushes clean spaces between teeth; rubber or wooden stimulators help remove plaque and stimulate gingival tissues when used appropriately.

What are floss holders and floss threaders used for?

A floss holder grips floss for easier cleaning; a floss threader guides floss beneath fixed bridges, orthodontic wires, or other appliances.

How should water irrigation devices be used according to the slides?

They flush food debris from brackets and prostheses. The slides warn against excessive pressure directed at the gingival sulcus and state that irrigation does not replace brushing and flossing.

What are the major parts of a manual toothbrush?

The head with bristles, the shank connecting head and handle, and the handle used to control brushing.

How do manual and mechanical (powered) toothbrushes differ?

Manual brushes rely on hand movement; powered brushes use electricity or batteries to move the head and generally require lighter applied pressure.

What five powered-toothbrush motions are illustrated in the slides?

Reciprocating (back-and-forth line), orbital (circle), vibratory (rapid back-and-forth), semicircular (arc), and elliptical (oval) motion.

What are the six toothbrushing techniques listed in the presentation?

Bass or Modified Bass, Charters, Modified Stillman, Rolling Stroke, Fones, and Modified Scrub.

What is the Bass or Modified Bass brushing technique used for?

Removing plaque along the gingival margin and directly beneath it, particularly where plaque collects near the gums.

What is the Charters brushing technique used for?

Loosening plaque and debris and stimulating marginal and interdental gingival tissues.

What is the Modified Stillman brushing technique used for?

General plaque removal combined with gingival stimulation and massage; the bristles are directed toward the tooth root.

What is the Rolling Stroke brushing technique?

A technique in which the brush is placed parallel to the teeth with bristles pointing apically, then moved toward the crown to remove plaque and stimulate gingiva.

What is the Fones brushing technique?

A simple technique using small circles over teeth; the slides recommend it as an easily learned introductory method.