Clinical Criteria of Normal Gingiva

Clinical Criteria of Normal Gingiva

• Healthy gingiva is typically described as coral pink (pale pink).
• Color is due to vascular supply, thickness, keratinization degree of epithelium, and presence of pigment-containing cells.
• Color is correlated with cutaneous pigmentation.
• Alveolar mucosa is red, smooth, and shiny.
• Physiologic pigmentation is common in Black individuals due to melanin, a non-hemoglobin-derived brown pigment.

Form of Gingiva

• Form depends on interdental area shape and size.
• Gingival margin usually terminates against the tooth in a knife-edge fashion.
• Interdental gingiva height varies with proximal contact location.
• Shape of interdental gingival papillae is correlated with teeth and embrasure shape.
• Broad interdental papilla is one type.
• Narrow interdental papilla is another type.

Contour of Gingiva

• Marginal gingiva surrounds the teeth in a collar-like fashion.
• It follows a scalloped outline (festooned) on facial and lingual tooth surfaces.
• Interradicular depressions and prominences correspond with root contours.
• On teeth with noticeable mesiodistal convexity (e.g., maxillary canines) or labial version, normal arc-like contour is emphasized, and gingiva is located more apically.
• On teeth in lingual version, gingiva is horizontal and thickened.

Consistency of Gingiva

• Gingiva is firm and resilient, except for movable free gingiva, which is tightly bound to underlying bone.
• Firmness of attached gingiva is determined by the collagenous nature of lamina propria.
• Gingival fibers also contribute to gingival margin firmness.

Surface Texture of Gingiva

• Gingiva's texture resembles an orange peel; dried gingiva is matte.
• Attached gingiva is stippled; marginal gingiva is not.
• Interdental papilla central portion is typically stippled, but marginal borders are smooth.
• Stippling is a form of adaptive specialization or reinforcement for function.
• It is related to the presence and degree of epithelial keratinization.

Microbiology of Periodontal Diseases

• As many as 500 different bacteria species colonize the oral cavity.
• They affect the delicate balance of host-bacterial interactions; leading to either health or disease.
• Periodontal infection is initiated by specific invasive oral pathogens colonizing dental plaque biofilms on the tooth root surface.
• Local and systemic factors modulate susceptibility to periodontitis.

Oral Microbiota and Oral Cavity

• Oral microbiota generally lives in harmony with the host.
• Disease can occur in special conditions, like reduced host response or increased pathogenicity.
• Most oral bacteria are commensal and beneficial.
• Oral cavity, with its microbiota, is a complex ecological system.
• Teeth and implants within oral cavity provide hard, non-shedding surfaces for bacterial deposits.

Classification of Bacteria

• Bacteria are classified by morphology, cell wall characteristics, oxygen requirements, and metabolism.
• Morphologies: cocci (spherical forms), rods (bacilli), spirochetes (spiral forms)
• Cell wall characteristics: gram-positive and gram-negative.
• Oxygen requirements: aerobes, anaerobes, facultative anaerobes, capnophilic microorganisms
• Metabolism: saccharolytic microorganisms (obtain energy from sugar breakdown), asaccharolytic microorganisms (do not ferment sugars).

Removal of Bacteria

• Oral cavity is an open system with nutrients and microbes.
• Bacteria removal mechanisms include saliva flow, gingival fluid flow, chewing, and epithelial cell desquamation (high turnover rate).
• Some bacteria are retained in pits/fissures, interdental areas, or under dental restorations' edges.
• Bacteria aggregate on tooth surfaces to form plaque.

Acquisition of Oral Flora

• Absolutely plaque-free oral cavity is unrealistic.
• Oral cavity is sterile at birth.
• Microorganisms appear within hours, transmitted from others and capable of adhering to the oral mucosa. Examples include Streptococcus salivarius.
• By 1 year, more complex flora is established, including Staphylococcus, Streptococcus, and Actinomyces species.
• Puberty marks a significant shift in oral flora; many periodontal pathogens become established.
• Shifts may be due to sex hormones; which sometimes replace vitamin K requirements by some bacteria.

Criteria for Identification of Periodontal Pathogens

• Defined by Robert Koch's postulates for establishing causal agent in human infections since 1870.
• Includes isolating from diseased individuals, growing in pure culture, inducing similar disease in susceptible animal models, recovering agent from lesions. Examples include Streptococcus mutans in dental caries.
• Sigmund Socransky's criteria (1992) further detail these criteria and include association with disease (increase in organims at diseased sites), elimination/decrease in sites with disease resolution, host response, capability to cause disease in experimental models, and evidence of virulence factors causing destruction.

Characteristics of Health-Related Bacteria

• Gram-positive.
• Aerobes or facultative anaerobes.
• Generally non-motile.
• Examples: Streptococcus sanguis, Streptococcus mitus, Actinomyces viscosus (yellow or purple complex).

Characteristics of Disease-Related Bacteria

• Predominantly Gram-negative.
• Cell walls have lipopolysaccharide (endotoxin) with significant pathogenic potential.
• Strict anaerobes.
• Non-motile and motile forms exist.
• Examples: Aggregatibacter actinomycetemcomitans, Prevotella intermedia (orange or red complex).

This quiz explores the clinical characteristics of normal gingiva, including its color, form, and contour. Participants will learn about the factors influencing gingival health and anatomy, with a focus on various types of gingival morphology. Ideal for dental students and professionals seeking to deepen their understanding of periodontal health.