Dental Indices Overview

Dental Indices

• Epidemiological indices attempt to quantify clinical conditions on a graduated scale.
• An index is a set of values (usually numerical) with maximum and minimum limits.
• Indices are used to describe variables, using the same criteria and methods to compare a specific variable in different populations.

Purposes of Indices

• Accurately assess the extent and severity of a disease, comparing disease status among individuals and communities.
• Identify the etiology (cause) and predisposing factors of a disease.
• Plan oral health policy.

Ideal Properties of an Index

• Clarity: The investigator should easily understand and apply the index rules.
• Simplicity: The index should be easy to apply to avoid time loss during examinations.
• Objectivity: The index should be clear and unambiguous in measuring intended characteristics.
• Validity: The index should accurately measure what it intends to measure (e.g., number of missing teeth in an adult is not a valid measure of caries activity).

Reliability and Quantifiability

• Reliability: The index should consistently measure the same variable over time and by different examiners.
• Quantifiability: The index should be suitable for statistical analysis and allow expressing group status with a numerical value on a scale.
• Sensitivity: The index should be able to detect small changes or shifts in the condition being measured.
• Acceptability: The index should not be painful or demeaning to the subject.

Types of Indices

• Simple index: Measures the presence or absence of a condition (e.g., plaque presence).
• Cumulative index: Measures all evidence of a condition, including past and present (e.g., DMFT index for dental caries).
• Irreversible index: Measures conditions that cannot return to normal (e.g., dental carries index DMF).
• Reversible index: Measures conditions that can be changed or reversed (e.g., gingival index GI).
• Composite index: Measures conditions that can return to normal (e.g., periodontal index).
• Full Mouth Indices: These indices use representative samples of dental apparatus, such as the periodontal index or dental fluorosis index.
• Simplified indices: Indices measuring only representative sample of dental apparatus (e.g. simplified oral hygiene index).
• A- Disease index (e.g. decay portion of DMF index).
• B- Symptom index (e.g. measuring gingival or sulcular bleeding).

Recommended Method for Performing an Index

• Explain the procedure to the patient.
• Drape the patient.
• Provide the patient with protective eyewear.
• Wash hands and wear personal protective equipment (PPE).
• Adjust the patient's position in the dental chair.
• Adjust the dental light for maximum illumination.
• Dry teeth with compressed air.
• Apply lubricant gel to the patient's lips.
• Follow the index procedure.

Epidemiology of Dental Caries

• Dental caries is a progressive, irreversible microbial disease affecting the calcified tissue of teeth.
• Pathogenesis (development) involves demineralization and destruction of both the organic and inorganic portions.
• The process begins with bacterial plaque and acid production from metabolizing carbohydrates.
• Demineralization occurs when the pH drops below a critical level (5.2-5.5), dissolving the tooth's minerals.
• Remineralization (redeposition of minerals) can reverse the process, but if it does not occur, a cavity forms.

Areas Prone to Dental Caries

• Enamel pits and fissures on occlusal surfaces (chewing surfaces) of molars and premolars.
• Buccal pits of molars and maxillary incisors.
• Surfaces adjacent to dentures or bridges.
• Proximal enamel surfaces (between teeth).

Classification of Dental Caries

• By location: Pit and fissure, smooth surface, root surface.
• By clinical appearance: Incipient, cavitation, gross destruction.
• By history: Primary, secondary, recurrent

Susceptibility of Different Teeth

• The Hagerstown study ranked the susceptibility of teeth to caries. Generally, molars are most susceptible, followed by premolars, and then incisors and canines.

Factors Affecting Dental Caries Development

• Host Factors: Tooth composition, morphology, position. Saliva composition, buffering capacity, quantity and viscosity. Age, sex, race, ethnicity, socioeconomic status, heredity, and emotional disturbances.
• Agent Factors: Microorganisms (bacteria) and dental plaque.
• Environmental Factors: Diet and nutrition, geographical variation (climate), oral hygiene, soil composition, and fluoride presence.

Tooth Morphology and Position

• Tooth morphology (shape) plays a role in caries development, with deep fissures trapping food particles and debris.
• Misalignment affecting tooth cleaning can also increase the risk.
• Posterior teeth (molars and premolars) are often more susceptible than anterior teeth (incisors and canines).

Tooth Composition

• Teeth are mainly composed of inorganic matter (enamel & dentin).
• The inorganic portion includes minerals like calcium and phosphorus.
• Fluoride increases the strength and resistance to demineralization.

Saliva

• Saliva plays a vital role in preventing caries.
• Saliva composition and flow rate affect the ability to neutralize acids produced by bacteria.
• High levels of salivary minerals (calcium, phosphate) are linked to a reduced risk of dental caries.
• Various components of saliva have antimicrobial and buffering properties.

Primary Prevention of Dental Caries

• Dietary control: Limiting sugary and carbohydrate-rich foods.
• Oral hygiene: Daily brushing and flossing are vital to remove plaque and food debris.
• Xylitol: A substitute for sugar known to reduce caries risk by interrupting bacterial metabolism.
• Pits and fissures sealants: These materials protect vulnerable areas of the tooth and prevent the progression of caries.
• Fluoride treatment: Topical or systemic fluoride applications make tooth enamel more resistant to acid attack, promoting remineralization.

Factors Contributing to the Decline of Dental Caries in Developed Countries

• Water fluoridation.
• Use of fluoride supplements and dentifrices.
• Increased awareness of dental importance.
• Improved dental resources and preventative care from practitioners.

Reasons for Increased Caries in Underdeveloped Countries

• Increased sugar intake.
• Limited access to dental resources.
• Socioeconomic factors.
• Lack of water fluoridation programs.
• Insufficient preventive dental programs.