Plaque Borders Research Articles

Access to subgingival plaque by disclosing agents using mouthrinsing and direct irrigation.

Teeth destined for extraction and exhibiting periodontal pockets had reference grooves cut on the proximal surfaces at the level of the gingival margin. A disclosing agent was then applied either as a mouthrinse or by direct irrigation at the entrance of the pocket. After extraction, the extent of apical penetration of the solution was measured from the reference point. Subsequently, the tooth was stained enabling similar measurements from the reference point to the level of the apical plaque border and the coronal level of the residual periodontal ligament. Analysis of these measurements indicated that neither mouthrinsing nor direct irrigation routinely achieved penetration of the solution to the apical plaque border. While mouthrinsing failed to achieve any significant penetration of pockets, the direct irrigation technique was partially effective. It was concluded that direct irrigation offers promise as a mode of application of chemical agents to subgingival plaque.

The Approximal Apical Border of Plaque on Children's Teeth: 1. Morphology, Structure and Cell Content

The Approximal Apical Border of Plaque on Children's Teeth: 1. Morphology, Structure and Cell Content

The Approximal Apical Border of Plaque on Children's Teeth: 2. Adhesion, Interbacterial Connections and Carbohydrate Metabolism

The Approximal Apical Border of Plaque on Children's Teeth: 2. Adhesion, Interbacterial Connections and Carbohydrate Metabolism

The host-organism interface in natural human dental plaque

This study concerns the adhesion of natural apical border plaque to approximal surfaces of children's posterior teeth. The predominant intact cells were poly saccharidecontaining cocci linked to the cuticle by means of mainly fibrillar or globular polysaccharide. Correlation of the features observed with those from studies of plaque formation and microbial adhesion in other habitats suggests that approximation of bacteria to enamel cuticle (and salivary pellicle) may be due to cross-linking and salt bridging of polysaccharide until mutually repulsive net negative surface charges are overcome. Low radius of curvature of bacterial processes and low pH, the latter to be expected at the subcontact area apical border in children, would favour reduction in bacterial surface potential. The final stages in bacterial adhesion in plaque seem to involve strong forces producing flattening of the cell wall at the site of the closest contact.

Immunoglobulins in human dental plaque

Immunoglobulins have been found previously in human gingiva, gingival fluid, serum and smeas of dental plaque. In the present study their presence and distribution in situ have been studied by immunofluorescence on the approximal surfaces of childen's teeth extracted due to caries or for orthodontic reasons. There wee also preliminary investigations of S. mutans distribution and of plaque immunoglobulins in grossly carious adult teeth. Positive fluorescence was in the order total Ig > IgG > IgA > IgM. S mutans (serotype c) was found in two of seven samples. Fluorescence was most marked at the apical plaque border, especially in relation to the contact area. This may relate to the prevalence of lysed organisms in this region. The topography and distribution of the different immunoglobulins correlate with previous studies suggesting gingival fluid (via plasma and gingival plasma cells) as the main source of the plaque immunoglobulin at the site of onset of approximal caries and chronic inflammatory periodontal disease.

The apical border of plaque in chronic inflammatory periodontal disease.

The apical border of plaque in chronic inflammatory periodontal disease.