Chapter 5

Question 1

what are contributory risk factors

Answer 1

• do not cause disease alone
• awareness of contributory local factors
• development of plaque-control activities
• design more specific plaque control programs

Question 2

what are examples of contributory local risk factors for perio

Answer 2

• previous disease activity: periodontal sites presently or previously affected by periodontitis
• dental calculus: secondary factor; mineralized plaque; porous surface (supra vs sub)

Question 3

what is the clinical significance of calculus

Answer 3

• different forms: ledge, rings, spicules, veneer, granular
• clinical vs radiograph interpretation: only 45% detected on x ray
• awareness of the public: calc/tartar, formation and consequence, sub vs supra, sulcus definition
• degree of contribution: does it make per worse?, conflicting studies regarding perio
• source: GCF for sub g, saliva for supra
• mineralization differs: supra calc usually adjacent to salivary sources
• retention sites: crowded teeth, out of occlusion, OHI

Question 4

when does supra calc form

Answer 4

• 24-72 hours starts
• 12-14 days or less for complete mineralization
• varies, some can be 24-48 hours
• supra is 30% mineralize

Question 5

what is the formation like for supra calc

Answer 5

• content of saliva: calcium and phosphorous
• saliva flow
• pH of saliva
• more basic saliva promotes crystallization
• lower pH less crystallization
• not just salivary flow
• link high caries to low calculus (cariogenic)
• link low caries to high calculus (calculogenic)

Question 6

what is the source of subgingival calc

Answer 6

• GCF: more minerals vs saliva, calcium, magnesium, fluoride
• pH more consistent: individualistic, some people form quicker than others, natural physiology
• 60% mineralized
• more black calc sub than supra
• more difficult to remove due to: hardness, attachment

Question 7

what are the 4 modes of attachment of subgingival calculus

Answer 7

1. mechanical locking: into irregularities in cementum
2. cementum/dentin: interlock with inorganic crystals of the tooth, usually cementum and resorbed areas of cementum
3. organic pellicle: weakened calculus
4. penetration into bacteria (not common in lit.)

Question 8

what are contributory factors of sub g calc

Answer 8

• anatomic factors
• root morphology
• cervical enamel projections: thin layer of calc, enamel pearls, clump of enamel
• palatogingival grooves: deep narrow perio pockets
• furcation defects: cul de sac, limited access
• position of the teeth: open contacts, crowding, accumulation
• iatrogenic factors: dental procedures, dental techniques
• restorative
• rough surface: sub gingival restoration, crowns
• over contoured restorations: impinge on gingiva, increase retention
• overhangs: increase probability of perio
• trauma
• dentures
• orthodontics
• endodontics
• traumatic factors like toothbrush trauma or factitious habits like finger nail biting and tooth picks which can change anatomy
• food impaction
• chemical injury
• occlusion
• oral piercings