Comprehensive Dental Assisting and Oral Anatomy Study Guide

Dental Restorative Materials and Agents

Calcium Hydroxide (Brand Names: Dycal / Life)
- Purpose: Irritates the pulp to promote the growth of secondary dentin.
- Pulp Protection: Protects the pulp through controlled irritation.
Cavity Varnish
- Primary Function: Seals the cavity preparation.
- Key Purposes:
  1. Prevents leakage around restorations.
  2. Prevents the penetration of acid from dental restorations into the dentin and pulp.
IRM and ZOE
- IRM: Intermediate Restorative Material.
- ZOE: Zinc Oxide Eugenol.
- Source: ZOE/IRM is derived from cloves.
- Purposes and Functions:
  - Calms and soothes the pulp (soothing effect).
  - Used for cementation.
  - Serves as an insulating base to prevent tooth sensitivity to amalgam.
  - A thick mix is utilized as a temporary restoration.
- Preparation Steps for IRM/ZOE Mixture:
  - Transfer one white scoop of powder to the dominant-hand side of the wax paper.
  - Transfer one drop of liquid to the opposite side of the wax paper.
  - Divide the powder into thirds.
  - Transfer the powder into the oil drop as needed until a thick mixture is formed.
  - Complete mixing within one minute.
Zinc Phosphate Cement
- Chemical Formula: $ZnPO_4$
- Preparation Steps:
  - Transfer one scoop of $ZnPO_4$ powder onto the dominant-hand side of a glass slab.
  - Transfer two drops of oil to the opposite side of the glass slab.
  - Transfer the powder into the oil drop as needed.
  - Mix on a cool glass slab to dissipate heat and prevent an exothermic reaction. Complete mixing within one minute; time is not affected.
- Purpose of a Thick $ZnPO_4$ Mixture:
  - Creates a base and acts as a thermal insulator.
  - Serves as a temporary sedative restoration.
- Cleaning Agent: Baking soda and water is a good agent to remove cement from instruments.

Cavity Classification and Tooth Surfaces

Classes of Cavities
- Class I: Involves pits and fissures on all teeth.
- Class II: Involves posterior teeth only; must involve a proximal surface.
- Class III: Involves anterior teeth only; involves proximal surfaces without including the incisal edge.
- Class IV: Involves anterior teeth only; involves proximal surfaces and the incisal edge.
- Class V: Involves the gingival $1/3$ of all teeth.
Tooth Surfaces
- Lingual: Surface closest to the tongue.
- Mesial: Surface towards the midline.
- Distal: Surface away from the midline.
- Incisal: Cutting edge of the tooth (anterior teeth only).
- Facial: Surface closest to the lips (anterior teeth only).
- Buccal: Surface closest to the lips (posterior teeth only).
- Occlusal: Chewing surface (posterior teeth only).

Dental Anatomy, Morphology, and Development

Anterior Teeth
- Types: Central incisors, lateral incisors, and cuspids (canines).
- Location: Positioned in the front of the mouth.
- Function: Used for cutting and tearing food.
- Cingulum: The lingual lobe of anterior teeth.
- Root Structure: Cuspids possess the longest roots in the dental arch.
Posterior Teeth
- Types: First bicuspid, second bicuspid, first molar, second molar, and third molar.
- Location: Positioned towards the back of the mouth.
- Function: Used for chewing food.
Primary Dentition
- Synonyms: Primary teeth are also referred to as deciduous, baby, or milk teeth.
Permanent Dentition Eruption
- First Eruption: Lower first molars are the first permanent teeth to erupt.

Craniofacial Anatomy: Sinuses and Salivary Glands

Sinuses
- Definition: Air sacs contained within the skull that communicate directly with the nasal cavity.
- Functions:
  - Produce mucus.
  - Lichten/make the bones of the skull lighter.
  - Provide resonance that may assist in sound production.
  - Warm incoming air.
- Types and Locations:
  - Maxillary Sinus: The largest sinus, located within the maxilla.
  - Frontal Sinus: Located in the forehead above the eyes.
  - Ethmoid Sinus: Consists of irregularly shaped air cells separated from the orbital cavity by a very thin layer of bone.
  - Sphenoid Sinus: Located close to the optic nerve.
Salivary Glands
- Parotid Gland:
  - The largest salivary gland.
  - Located subcutaneously (below the skin) near the cheek and ear.
  - Saliva enters the oral cavity through Stenson's Duct (an opening through the parotid).
- Submandibular Gland:
  - Approximately the size of a walnut.
  - Located in the floor of the mouth.
  - Duct outlet: Wharton's duct, situated just lingual to the mandibular incisors.
- Sublingual Gland:
  - The smallest salivary gland.
  - Located on either side of the tongue.
  - Saliva enters through the ducts of Rivinus / Bartholin's duct under the tongue.
Saliva Properties
- Functions:
  - Lubricates the oral cavity.
  - Aids in digesting food.
  - Acts as a natural cleansing agent.
  - Functions as a buffer to reduce the pH of the mouth.
  - Provides protection against tooth decay/cavities.
- Daily Production: Average saliva production is approximately $3\,\text{pints}$ per day.

Musculature, Systemic Health, and Pulp Physiology

Muscles of Mastication
- Temporal Muscle: Elevates the mandible and closes the jaw.
- Masseter Muscle: Elevates the mandible and closes the jaw during chewing.
- Masseter Helper Muscles:
  - Internal Pterygoid: Closes the jaw.
  - External Pterygoid: Opens the jaw.
Endocrine System
- Thyroid Gland: Identified as one of the largest endocrine glands in the body.
Pulp Functions and Physiology
- Primary Roles:
  - Promotes sensory responses.
  - Produces odontoblasts.
- Protection: Protected through the application of materials such as Calcium Hydroxide.
Systemic Health and Prophylactic Antibiotics
- Indication: Prophylactic antibiotics are prescribed to patients with heart-related conditions prior to dental appointments.
- Rheumatic Fever Protocol: Provided to all patients with a history of Rheumatic fever to prevent potential bacterial damage to the heart.