Oral Tissues and Tooth Structure

Overview of Oral Tissues

• The oral cavity is composed of several tissues that work together to form a functional unit.

Enamel

• Hardest substance in the human body
• 96% inorganic material (hydroxyapatite), 3% organic material, and 1% water
• Highly resistant to decay and wear
• No living cells or nerves present

Dentin

• Makes up majority of tooth structure
• 70% inorganic material, 20% organic material, and 10% water
• Contains dentinal tubules that transmit sensation to pulp
• Living cells (odontoblasts) present in dentinal tubules

Cementum

• Thin layer of bone-like tissue covering root of tooth
• 45-50% inorganic material, 30-35% organic material, and 20-25% water
• Helps anchor tooth to surrounding bone

Pulp

• Soft tissue at center of tooth containing:
  • Nerves
  • Blood vessels
  • Lymphatic vessels
  • Connective tissue
• Responsible for tooth development and maintenance

Periodontium

• Supporting tissues surrounding tooth, including:
  • Gingiva (gums)
  • Periodontal ligament (connective tissue)
  • Cementum
  • Alveolar bone
• Attaches tooth to surrounding bone and maintains tooth position

Gingiva (Gums)

• Mucous membrane covering jawbone and surrounding tooth
• Composed of epithelial and connective tissue layers
• Protects underlying tissues from bacteria and trauma

Oral Tissues

• The oral cavity consists of several tissues that work together to form a functional unit.

Enamel

• Composed of 96% inorganic material (hydroxyapatite), 3% organic material, and 1% water.
• Hardest substance in the human body, highly resistant to decay and wear.
• Lacking living cells and nerves.

Dentin

• Makes up the majority of the tooth structure.
• Composed of 70% inorganic material, 20% organic material, and 10% water.
• Contains dentinal tubules that transmit sensation to the pulp.
• Odontoblasts (living cells) are present in dentinal tubules.

Cementum

• A thin layer of bone-like tissue covering the root of the tooth.
• Composed of 45-50% inorganic material, 30-35% organic material, and 20-25% water.
• Helps anchor the tooth to surrounding bone.

Pulp

• A soft tissue at the center of the tooth containing:
  • Nerves
  • Blood vessels
  • Lymphatic vessels
  • Connective tissue
• Responsible for tooth development and maintenance.

Periodontium

• Supporting tissues surrounding the tooth, including:
  • Gingiva (gums)
  • Periodontal ligament (connective tissue)
  • Cementum
  • Alveolar bone
• Attaches the tooth to surrounding bone and maintains tooth position.

Gingiva (Gums)

• A mucous membrane covering the jawbone and surrounding tooth.
• Composed of epithelial and connective tissue layers.
• Protects underlying tissues from bacteria and trauma.