Plaque and Calculus Flashcards
When the colonization of the oral cavity starts?
Day 1 - Starts at birth with facultative and aerobic bacteria
When the anaerobic bacteria can be detected?
Day 2
When mature microbiota is established in gut of newborn?
Day 14 (by 2 weeks)
What are 6 Major Ecosystems in Oral Cavity?
• Intraoral, supragingival, hard surfaces • Periodontal/peri-implant pocket • Buccal epithelium, palatal epithelium and floor of mouth • Dorsum of tongue • Tonsils • Saliva
What is the dental plaque?
A structured, resilient, yellow-grayish substance that adheres tenaciously to the intraoral hard surfaces, including removable and fixed restorations
Name two categories of plaques:
- Supragingivalplaque
* Subgingivalplaque
True or False: Plaque is differentiated from materia alba and calculus
True
Name three major phases of plaque formation:
- Formation of pellicle on the tooth surface
- Initial adhesion and attachment of bacteria
- Colonization and plaque maturation
True or False: All surfaces of oral cavity are coated with a pellicle
True
When Dental pellicle are obvious?
Within nanoseconds after polishing teeth they are covered with saliva-derived layer = derived pellicle
What pellicle consists of:
Pellicle consists of glycoproteins, proline-rich proteins, phosphoprotein, histidine-rich proteins, enzymes . . .
Adhesion sites for bacteria
What are the mechanisms of Dental pellicle formation (The molecule bonds):
Mechanism of formation electrostatic, van derWaals, hydrophobic forces
Name the 3 phases of Initial Adhesion and Attachment of Bacteria:
- Phase 1: transport to surface/random contact.
- Phase 2: initial adhesion – reversible
- Phase 3: attachment – firm anchorage
Which phases of Initial Adhesion and Attachment of Bacteria are non-specific and which one is specific?
- Phase 1 and 2 are non-specific
* Phase 3 depends on specific interactions between microbial cell adhesin molecules and receptors in pellicle
The action of teeth and implants in the formation of calculus and entry of bacteria:
• Provide hard, non-shedding surface that allows development of extensive structured bacterial deposits
• Unique ectodermal interruption
• Teeth are “port of entry” for
periopathogens
• Key periodontal pathogens will disappear after full mouth extractions
Define supragingival plaque: (What is supragingival?)
Which bacteria are prominent at the tooth surface and which bacteria predominate at the outer surface?
- Defined as marginal plaque when in contact with gingival margin
- Gram positive cocci and short rods predominate at the tooth surface
- Gram negative rods and filaments, spirochetes predominate at outer surface
Topography of supragingival plaque. (Explain initial growth and further extension)
- Initial growth along gingival margin and from interdental space
- Further extension in coronal direction • Changes with surface irregularities
Factors Affecting Supragingival Dental Plaque Formation
- Rough surfaces* accumulate and retain more plaque
- Thicker plaque has more pathogenicity, more motile organisms, spirochetes, denser packing
- Smoothing surface decreases rate of formation
In which jaw the plaque forms faster?
Forms faster in lower jaw versus upper
In which areas plauqe formation is faster?
Forms faster in lower jaw versus upper • Forms faster in molar areas • Forms faster on buccal surfaces of teeth • Forms faster interproximaly compared to strict buccal or lingual
Individual Variables Influencing Plaque Formation
- Rate of formation differs significantly between subjects
- Saliva-induced aggregation and relative salivary flow conditions explain 90% of variation
- Other factors include diet, chewing fibrous foods, smoking, tongue and palate brushing antimicrobial factors in saliva . .
- Age does NOT influence de novo plaque formation
• Plaque in older people led to more gingivitis • Plaque forms faster adjacent to inflamed vs
healthy gingiva
• Plaque is NOT removed spontaneously during eating
What is subgingival plaque?
- Subgingival plaque differs due to the availability of blood products and anaerobic environment
- Are specific microorganisms the cause of the consequence of disease?
- Periodontal pathogens that are strict anaerobes may contribute little to the initiation of disease
Explain De Novo subgingival plaque formation (Is it easy to remove?) (Effect of remaining bacteria) (pathogens action) (Growth after pre-treatment)
• Difficult to completely remove
• Remaining bacteria are source for re-
colonization
• Some pathogens penetrate soft tissue and dentinal tubules
• Fast re-growth to pre-treatment level within 7 days
Does age influence de novo plaque formation?
No
Does saliva influence de novo plaque formation?
Yes
What is Tooth-associated Subgingival Plaque?
(looks like which calculus?)
(what happens to deep pocket and apical portion?)
- Tooth-associated cervical plaque similar to supragingival plaque
- Deeper parts of pocket less filamentous
- Apical portion dominated by smaller organisms without particular orientation
Which bacteria are involved with Tissue associated Subgingival Plaque?
• Contain primarily gram(-) rods and cocci, as well as large numbers of filaments, flagellated rods, and spirochetes