Dental Caries: Definition, Causes, Pathology, Clinical Features & Treatment

Dental caries is a multifactorial, infectious disease characterized by the progressive demineralization and destruction of the enamel, dentin, and cementum due to bacterial activity, leading to the formation of cavities.

Etiology (Causes & Risk Factors):

1.     Microorganisms:

• Streptococcus mutans (primary causative agent).
• Lactobacillus acidophilus (responsible for deep dentin caries).
• Actinomyces (involved in root caries).

2.     Dietary Factors:

• High carbohydrate intake (Sugars, Starches) – Especially sucrose, glucose, and fructose.
• Frequent snacking – Promotes acid production by bacteria.

3.     Salivary Factors:

• Decreased salivary flow (Xerostomia) – Reduces natural cleansing and buffering action.
• Low salivary pH – Increases susceptibility to caries.

4.     Host Factors:

• Tooth Morphology: Pits, fissures, and deep grooves increase caries risk.
• Enamel Defects (Hypoplasia, Fluorosis) – Weaken enamel resistance.

5.     Poor Oral Hygiene:

• Inadequate brushing and flossing allow plaque accumulation.

6.     Genetic Factors:

• Family history and genetic susceptibility play a role.

Pathogenesis (Key Stages of Dental Caries Development):

1.     Plaque Formation:

• Bacteria adhere to the tooth surface and form a biofilm (dental plaque).

2.     Acid Production:

• Bacteria ferment dietary sugars, producing acid (lactic acid), which lowers pH.

3.     Demineralization:

• Acid dissolves calcium and phosphate from enamel and dentin.

4.     Cavity Formation:

• Continued destruction leads to cavity formation, extending into dentin and pulp.

Clinical Features:

1.     White Spot Lesion (Early Stage):

• Chalky white appearance due to enamel demineralization.
• Reversible with fluoride treatment.

2.     Cavity Formation (Moderate Stage):

• Brown/Black discoloration in pits, fissures, or smooth surfaces.
• Sensitivity to hot, cold, and sweet foods.
• Pain on chewing in deeper lesions.

3.     Pulpal Involvement (Severe Stage):

• Spontaneous, throbbing pain (irreversible pulpitis).
• Possible abscess formation and swelling.

4.     Root Caries (In Elderly Patients):

• Affects cementum and dentin, common in gingival recession cases.

Classification of Dental Caries:

1. Based on Location:

• Occlusal Caries – On the biting surface of molars & premolars.
• Smooth Surface Caries – On the proximal or buccal surfaces.
• Pit & Fissure Caries – In deep grooves of molars & premolars.
• Root Caries – On exposed root surfaces (common in elderly).

2. Based on Progression:

• Acute Caries – Rapidly progressing, soft, and light-colored lesions.
• Chronic Caries – Slow progressing, dark brown, and hard lesions.

3. Based on Affected Tissues:

• Enamel Caries – Limited to enamel.
• Dentin Caries – Extends into dentin, causing sensitivity.
• Pulpal Caries – Reaches the pulp, leading to pain & infection.

Diagnosis:

1. Clinical Examination:
• Visual inspection with a dental mirror & explorer.
2. Radiographic Examination:
• Bitewing X-rays – Best for detecting interproximal caries.
• OPG (Orthopantomogram) – For full-mouth assessment.
• CBCT (Cone Beam CT) – For advanced cases.
3. Fiber-Optic Transillumination (FOTI):
• Helps detect early-stage caries.
4. Laser Fluorescence (DIAGNOdent):
• Measures bacterial activity in carious lesions.

Differential Diagnosis:

• Fluorosis: White, opaque areas with no cavitation.
• Hypoplastic Enamel: Developmental defect, not bacterial in origin.
• Attrition, Abrasion, Erosion: Wear due to mechanical or chemical factors.

Treatment:

1. Non-Surgical Management (For Early Caries):

• Fluoride Therapy:
• Topical Fluoride Application (Sodium Fluoride, Stannous Fluoride).
• Fluoridated Toothpaste & Mouthwash prevent demineralization.
• Dietary Modifications:
• Reduce sugar intake, avoid frequent snacking.
• Increase intake of calcium, phosphate, and vitamin D.
• Pit & Fissure Sealants:
• Applied to deep grooves of molars to prevent caries.

2. Restorative Treatment (For Moderate Caries):

·        Filling (Restoration):

• Glass Ionomer Cement (GIC) – Releases fluoride, used in small cavities.
• Composite Resin (Tooth-Colored Filling) – Used in esthetic areas.
• Amalgam Filling – Strong, durable, used in posterior teeth.

·        Root Canal Treatment (RCT):

• Required if caries extends to the pulp.
• Involves removal of infected pulp, cleaning, and filling with gutta-percha.

·        Crown Placement:

• Metal, porcelain, or zirconia crowns placed after RCT for protection.

3. Extraction (For Severe Cases):

• If the tooth is grossly decayed and non-restorable, extraction is done.
• Replacement options: Dental implants, Bridges, or Dentures.

Complications of Untreated Caries:

• Pulpitis (Reversible/Irreversible) – Inflammation of pulp.
• Periapical Abscess – Pus formation at tooth root.
• Osteomyelitis of Jaw – Bone infection due to spread of bacteria.
• Ludwig’s Angina – Life-threatening deep neck space infection.
• Tooth Loss & Malocclusion – Affects chewing and aesthetics.

Prevention:

1.     Good Oral Hygiene:

• Brush twice daily with fluoride toothpaste.
• Floss daily to remove interdental plaque.
• Use antiseptic mouthwash (Chlorhexidine).

2.     Regular Dental Check-Ups:

• Every 6 months for early detection and preventive care.

3.     Dietary Modifications:

• Reduce sugar and starch intake.
• Increase calcium, phosphorus, and vitamin D intake.

4.     Fluoridation Programs:

• Water fluoridation in communities helps prevent caries.

5.     Pit & Fissure Sealants:

• Applied in children to prevent caries in permanent molars.

Homeopathic Medicines:

1.     Calcarea Fluorica

• Weak, brittle teeth prone to decay.
• Deep-seated pain in carious teeth.
• Excessive sensitivity to hot and cold.

2.     Silicea

• Teeth decay easily despite good oral hygiene.
• Foul-smelling breath with pus formation in cavities.
• Delayed eruption of teeth in children.

3.     Staphysagria

• Black, decayed teeth in children.
• Toothache aggravated by emotional stress.
• Pain from even the slightest touch.