ICP Flashcards
(183 cards)
What organisms causes acute ulcerative gingivitis?
Spirochaetes eg treponema
Fusobacterium
Where are oral obligate anaeobic bacteria found?
Root canal and pulp chambers infection
Abscess
Advanced periodontitis
Carious dentine
What is the most prevalent type of fungi in the mouth?
Candida albicans
Which bacteria are found on oral mucosal surfaces
Streptococcus salivarious
Which gram positive cocci are present as commensal flora in high numbers in saliva and on tongue
Facultative streptococci
Which bacteria forms black pigmented colonies on blood agar
Porphyromonas, prevotella - they are obligate anaerobic bacteria and comprise large prop of microflora in dental plaque. Rarely found in health. Isolated from subgingival sites.
What is caries
Loss of tooth substance by metabolically produced acids.
Common in pits, fissures.
What does statherin do
Binds to calcium phosphate to prevent it from precipitating out, therefore maintaining levels of calcium for remin of tooth and phosphate for buffering action.
What are the iatrogenic (drug) causes of xerostomia?
Aspirin- NSAIDS Diuretics eg furosemide Antihypertensive eg atenolol, clonidine. Antiepileptic eg phenytoin (grandmal) Antihistamine eg loratadine
Which autoimmune condition can cause xerostomia
Sjogrens syndrom - causes acinar destruction in salivary gland therefore reduced saliva production = higher risk of infections eg candidiasis and caries
What is a fissure sealant
Material placed in fissures and pits to PREVENT and ARREST development of caries.
It is a preventive * measure.
What materials are used for fissure sealant
Unfilled resin or filled - light/chemically cured.
GIC - when isolation is a problem eg partially erupted teeth in high caries risk child.
SR procedure
Clean - rubber cup, rotary brush, air abrasion
La - if multiple teeth need it, or if caries into dentine.
Rubber dam if la was used or other isolatuon.
Caries removal, minimal, use 330 tungsten carbide, make edj caries free.
Primer - hema containing - bonds to collagen via OH bonds, apply 15s n air dry 5s. Rub it in using microbrush.
Bond, sensitive to light, seals dentinal tubules, apply 15s n air3s, light cure 20s.,
Apply comp resin or flowable comp if cavity too small. Light cure. Check for defects using probe n remove excess.
Apply FS to remaining pits n fissures, occlusal palatal n buccal. 1/3 cuspal incline. Use microbrush. Cure 20s.
Check occlusion
Why is isolation needed for fissure sealant
Cuz the etched enamel is porous and may get contaminated with debris during procedure which will reduce n prevent resin tag formation of composite bond to the enamel.
When is a SR/PRR indicated
When diagnostic methods, visual inspection, and bitewing radiographs have shown that a stained fissure has progressed to a lesion just into dentine. (If has progressed more then will require conventional restoration)
Advantages of air abrasion (aluminium oxide/ sodium bicarbonate particles)
1) no vibrations therefore painless n noiseless
2) doesnt result in a smear layer during tooth prep
3) carious tissue removed without affecting healthy teeth
4) no post op sensitivity
5) no burning smell or micro fractures in teeth tht often occurs with drilling.
6) sealants and fillings bond better to tooth
What are the effects of cavity prep on dentine?
Produces vibrations which may cause shift in pulpal blood flow
Will cause pain due to presence of nerve endings in dentine tubules.
Will cause fluid shifts eg cut dentine causes outward fluid shift n collagen deposition forming a smear layer
Odontoblasts may get displaced into dentine tubules n will die, but if dentine is sterile then new odontoblasts can differentiate from stem cells in pulp.
What is enamel hypoplasia
enamel matrix formation is defective resulting in thinned, grooved, pitted enamel.
Wats hypomineralisation
Disturbance of calcification of enamel whereby it is weak n prone to breakdown. seen alongside hypoplasia but one predominates usually.
Why is calcium hydroxide bacteriostatic?
Cuz its alkaline ph11
Cuz it absorbs co2 which is a metabolic requirement of the obligate anaerobic bacteria that are present in dentine caries and pulpitis
Functions of PDLs
Sensory info
Dissipates masticatory forces therefore protecting the tooth.
Source of stem cells for new bone, cementum, other CT cell types.
What is a periodontal pocket (its different to gingival pocket)
A sulcus that has deepened due to loss of periodontal attachment, the resultant depth will be greater than the normal 3mm.
5 points characterising gingivitis
1) gingival oedema (therefore loss of contour)
2) hyperaemia (therefore bleeding and redness) - excess of blood supplying your gingiva
3) increased gcf flow and containing neutrophils
4) increased lymphocytes and plasma cells in the infiltrate indicate increased severity
5) reversible !
5 points characterising periodontitis
1) similar inflam infiltrate to chronic gingivitis
2) PDL and alveolar crestal bone is lost which may be follower by gingival recession
3) apical migration of junctional epithelium resulting in deeper pocketing more than 3mm
4) tooth mobility
5) irreversible