Quiz 3 (Sessions 12-20) Flashcards
Define “Preparation” Step
Grind tooth circumferentially and on top
Why is a diagnostic wax up performed?
To idealize the tooth contours for the final restoration.
What does a provisional act as?
Prototype to test out the new contours for esthetics and function.
What is a by-product of condensation setting reaction?
Ethyl alcohol
What was developed to overcome the large polymerization shrinkage of condensation silicone impression material?
Putty
Define Biologic Width
The combined width of connective tissue and junctional epithelial attachment formed adjacent to a tooth and superior to the crestal bone.
How can the biological width be identified?
Probing to the bone (referred to as sounding to bone) and subtracting the sulcus depth from the resulting measurement.
What are examples of clinical situations where the crown margin is placed deep sulcus into the biologic width?
Removal of caries, placing margin on tooth structure instead of restorative material (like previous class V), subgingival tooth fracture and iatrogenic prep.
When is the biologic width violated or invaded?
When a margin is placed within the biologic width (junctional epithlium or connective tissue)
What two things can occur when the biologic width is violated?
Inflammation and bone loss`
What is one possibility for bone loss of an unpredictable nature along with gingival tissue recession?
Body’s attempt to recreate room between the alveolar bone and the margin to allow space for tissue reattachment.
Where is bone loss of unpredictable nature more likely to occur?
In areas where alveolar bone surrounding the tooth is very thin in width
_____ from restorative procedures can play a major role in causing this fragile tissue to recede.
Trauma
What type of tissue is more prone to recession?
Highly scalloped, thin gingiva
What type of tissue is not likely to recede?
Thick fibrous tissue
Two examples of clinical scenarios that cause a violation within biologic width
Removal of caries
Iatrogenic crown prep
What is invaded when the bur is carried in a straight line to connect the facial and lingual?
Biologic width
The ____ ____ follows the contour of the boney architecture that underlies and supports it.
Soft tissue
What are two ways to treat violation of biologic width?
Surgical crown lengthening
Rapid orthodontic extrusion
Describe surgical crown lengthening
Flap is reflected -> Bone is removed w/ bur or hand instrument -> Biologic width is reestablished after healing
How long does surgical crown lengthening take to heal?
Esthetic -> 4-6 months
When should the final impression be made after surgical crown lengthening?
4-6 months
Describe the crown and gingival margin after surgical crown lengthening
Gingival margin is moved apically
Incisal edge of tooth is the same height.
Describe rapid orthodontic extrusion
Tooth is extruded until the margin is moved out of the biologic width -> Bone fills socket as tooth is extruded
