Étude sur l'attachement parodontal

Introduction

• The study examines the periodontal attachment, composed of the junctional epithelium (epithelial attachment) and the connective tissue attachment (gingival and periodontal fibers).
• The destruction of this attachment is a characteristic of periodontal disease.
• Partial or complete repair/regeneration can occur. Regeneration is typically accomplished with surgical procedures.
• Healing can be a result of remission from disease or from a treatment.

Review of Periodontal Epithelium

• Periodontal epithelium includes oral epithelium (keratinized stratified squamous epithelium).
• It lines the vestibular/lingual/palatal surfaces of the gum.
• It also consists of the sulcular epithelium( non keratinized), lining the gingival sulcus (gingival crevice), which is connected to the tooth surface by the junctional epithelium.

Definitions

• Epithelial Attachment: A biologic barrier separating oral cavity from the underlying tissues. This barrier ensures integrity for the structures beneath.
• Connective Tissue Attachment: Fibrous connective tissue (containing gingival and periodontal fibers) connects the gingiva to the tooth structure.

Constituents of the Gingival Sulcus (GS)

• Remains of the primary junctional epithelium.
• Multilayered, non-keratinized sulcular epithelium extends along the tooth surface forming the junctional epithelium.
• The GS bottom contains remnants of the junctional epithelium, sometimes in layers.

Histological Structure of the Epithelial Attachment

• Dental Cuticle: A thin electron-dense layer located between enamel and ameloblasts.
• Boundary Layer: A thin, electro-dense structure between the tooth and the inner basal lamina. This is inconsistent in crown regions.
• Acellular Acellular Acellular Cementum: A mineralized layer adjoining enamel and/or cementum. It's non-cellular, and non-fibrous.
• Inner Basal Lamina: A structural link between the enamel/cementum and junctional epithelium.
• Hemidesmosomes: Junctional structures anchoring junctional epithelium to the basal lamina.
• Junctional Epithelium: Non-keratinized stratified squamous epithelium.
• Outer Basal Lamina: Separates the junctional epithelium from the connective tissue.

Characteristics of Junctional Epithelium vs. Other Epithelia

• Number of layers: Junctional epithelium has fewer layers.
• Organelles: Junctional epithelium has fewer cytoplasmic organelles.
• Tonofilaments: Junctional epithelial tonofilaments are lower in density.
• Hemidesmosomes: Dense in junctional epithelium.
• Keratin: Absent in the junctional epithelium, but present in other oral epithelium.
• Intercellular spaces: Junctional epithelium has spaces that are more permeable (18% versus 12%) than other types.
• Papillae: Junctional epithelium lacks papillae found in other oral tissues.

Physiology of the Epithelial Attachment

• Adhesion: Interaction between the epithelial attachment's components creates a biological bond.
• Homeostasis: Constant renewal and turnover of junctional epithelial cells is essential.
• Dynamic nature: The epithelial attachment is not static; its location and structure change as teeth erupt. The location of the attachment is vital in protecting the underlying structures.
• Defense Potential: This attachment plays a crucial role by providing a barrier against harmful elements and substances in the oral cavity. Key aspects include permeability, phagocytosis, and cell adhesion.

Ce quiz explore l'attachement parodontal, y compris l'épithélium de jonction et le tissu conjonctif. Il aborde les effets des maladies parodontales et les procédures de régénération chirurgicale. Testez vos connaissances sur l'anatomie et la physiologie de la gencive.