Ch. 16

Question 1

local contributing factors for perio

Answer 1

oral conditions or habits that increase an individual’s susceptibility to perio infection; they don’t initiate disease but contribute to disease process. ex: calculus, faulty dental restorations, developmental defects in teeth, certain pt habits, trauma, occlusion

Question 2

disease site

Answer 2

individual tooth or specific surface of a tooth

Question 3

dental calculus

Answer 3

• mineralized biofilm, can occur 48 hrs-2 weeks later.
• surface is irregular, covered in biofilm, and can lead to biofilm retention.
• inorganic portion 70-90%, calcium phosphate primarily but also calcium carbonate and magnesium phosphate
• organic portion 10-30%, materials derived from biofilm, dead epithelial cells, dead white blood cells, living bacteria

Question 4

types of dental calculus

Answer 4

• as calculus ages, it changes through several crystalline forms.
• newly formed calculus appear as crystalline form called brushite
• more mature but less than 6 mo old calculus primarily hydroxyapatite

Question 5

supragingival calculus

Answer 5

• located coronal to gingival margin
• also called supramarginal calculus and salivary calculus
• usually found in localized areas such as lingual surfaces of mandibular molars, facial surfaces of maxillary molars, and on teeth that are crowded or in malocclusion
• frequently found near large salivary ducts

Question 6

subgingival calculus

Answer 6

• located apical to gingival margin
• also called submarginal calculus and serumal calculus
• shape is most often flattened (thought to be this shape because of pressure of pocket)
• may be localized or generalized

Question 7

modes of attachment

Answer 7

1. attachment by means of pellicle: most common on enamel surfaces, usually removed easily
2. attachment to irregularities to tooth surface: includes cracks in teeth, tiny openings left where pdl fibers detached, grooves in cemental surfaces created as a results of faulty instrumentation, difficult to remove since deposits can be sheltered in those tooth defects
3. attachment by direct contact of the calcified component and the tooth surface: matrix of calculus deposit is interlocked in tooth surface, difficult to remove

Question 8

morphology

Answer 8

study of anatomic surface features of teeth

Question 9

overhanging restoration

Answer 9

when restoration is not smoothly contoured with tooth surfaces, often impossible for pt to clean, needs to be corrected by DH

Question 10

dental caries

Answer 10

can increase retention of plaque since caries can result in defects in tooth structure

Question 11

tooth grooves or concavities

Answer 11

• palatogingival groove: sometimes grooves form on palatal surfaces of some incisor teeth, frequently seen on maxillary lateral incisors
• mesial surface of maxillary first premolars teeth often have pronounced concavity that is natural contour but if exposed in oral cavity, can make it difficult for pt to maintain effective self care

Question 12

pathogenicity

Answer 12

the ability of a disease causing agent to actually produce the disease

Question 13

plaque biofilm maturation

Answer 13

1. after cleaning, salivary proteins attach to form pellicle
2. within 2 days, pellicle is colonized with gram positive aerobic cocci and rods (cause gingivitis)
3. over next week, other bacteria enter plaque biofilm includes some gram negative anaerobic cocci and gram positive rods; in addition, Fusobacterium species and Prevotella intermedia can invade (perio bacteria)
4. later, Porphyromonas gingivalis colonize.

Question 14

food impaction

Answer 14

refers to forcing food between teeth during chewing, trapping it in interdental area; can strip gingival tissues away from tooth surface and contribute to perio breakdown; can lead to alterations in gingival contour that result in interdental areas that are difficult for pts to clean

Question 15

direct damage from pts

Answer 15

• tongue thrusting, mouth breathing, improper use of aids

Question 16

direct damage due to faulty restorations and appliances

Answer 16

• inappropriate crown placement
• a crown margin that is closer than 2mm to crest of alveolar bone can result in resorption of alveolar bone
• biologic width: space on tooth occupied by je and connective tissue attachment fibers; can be violated or damaged by restoration margins
• bulky crowns/restorations can encroach on embrasure space
• a poorly fitting prosthesis can impinge on tissue and favor biofilm accumulation

Question 17

direct damage from occlusal forces

Answer 17

• when excessive occlusal forces cause damage to periodontium
• can cause bone resorption because of increased pressure
• signs include tooth mobility, sensitivity to pressure, migration of teeth
• radiographic signs include enlarged, funnel shaped pdl space, alveolar bone resorption
• primary trauma from occlusion: excessive occlusal forces on sound periodontium
• secondary trauma from occlusion: normal occlusal forces on unhealthy periodontium previously weakened by perio
• functional occlusal forces: normal forces produced during act of chewing food
• parafunctional occlusal forces: result from tooth to tooth contact like clenching and bruxism