Chapter 2 B: General Concepts Of Cavity Preparations Flashcards
A tooth (cavity) preparation:
It’s a mechanical alteration of a tooth to make it:
1. Disease free
2. To give it a shape that can retain the restorative material
The restorative material in the cavity will?
Maintain the original morphology of the tooth and provide proper function and aesthetics
FAM
In the tooth preparation, we remove all the diseased tooth structure, avoiding?
Pulpal exposure
What occurs when the carious dentin remains at the same time as the restorative material is being placed?
- pain
- sensitivity
- fracture of the restoration
- caries progression
PSFC
The tooth is prepared in a way that ensures the ?
- placement of margins of the restorative material into accessible areas, with sufficient retention for restorative material, and protection of vital pulp organ
What is a pathological cavity?
Empty space produced in the teeth by pathological, traumatic, or congenital processes
TPC
What is a therapeutic cavity?
Artificial space given to a tooth to rebuild it with appropriate materials and techniques that will return the anatomy, function, and aesthetics
We transform a ____ cavity into a ____ cavity?
Pathological —> therapeutic
Cavities can be classified into?
5:
1. Based on the number of tooth surfaces involved
2. Based on the location
3. Based on the filling material
4. Based on the purpose
5. Black’s classification (Etiological, localisation)
Based on the number of tooth surfaces involved:
- simple, compound, and complex
A simple cavity preparation is?
One that only involves one tooth surface
Ex: occlusal
A compound cavity preparation is?
One that involves two surfaces
Ex: mesio-occlusal
A complex cavity preparation is?
One that involves more than 2 surfaces
Ex: MOD
Mostly Inter-proximal caries are?
Compound
Because there’s almost always an adjacent tooth that prevent you from accessing the proximal surface so you have to access through the occlusal surface, 2 surfaces
Based on the location:
- occlusal: simple (O)
- mesio-occlusal, disto-occlusal, buccal-occlusal: compound (MO, DO, BO)
- mesio-occlusal-distal, mesio-occlusal-buccal: complex (MOD, MOB)
Based on the filling material:
5:
- cavities for amalgam
- cavities for CR
- cavities for direct gold
- cavities for GIC
- cavities for casting inlays
Based on the purpose:
3:
- cavities for prosthetic purposes
- cavities for prevention purposes
- cavities for therapeutic purposes
P 2 T
Based on Black’s classification:
- in relation to the etiological forms of caries, more focused on the localisation of caries than it’s etiology
What is the most common and used cavity classification?
Black’s classification
A class I cavity is?
- pit and fissure cavities occur in the occlusal surfaces of premolars and molars
- the occlusal two-thirds of facial and lingual of molars
- lingual surface of incisors
- any other abnormal position
A class II cavity is?
Cavities in the proximal surfaces of premolars and molars
A class III cavity is?
Cavities in the proximal surface of anterior teeth no involving the incisal angle
A class IV cavity is?
Cavities in the proximal surface of anterior teeth involving the incisal angle
A class V cavity is?
Cavities in the gingival third of facial and lingual or palatal surfaces of all teeth
Cavities can be formed by?
- boxes
- angles
- walls
BAW
Cavity boxes are?
Well defined spaces that will house the filling material
The shape of the box varies depending on?
The location of the lesion and the restorative material that will be used
Based on the shape, they can be?
Retentive or expulsive
A retentive box is?
Capable of maintaining the filling material without departing
An expulsive box is?
Which don’t maintain the filling material themselves
Boxes for amalgam are?
Retentive
Boxes for CR are?
Expulsive , rounded boxes
If a cavity is formed by 2 boxes, the joint is known as?
Isthmus
External walls are?
A wall in the prepared cavity surface that extends to the external tooth surface
What are the external walls?
Mesial, distal, lingual, and buccal
Internal walls are?
It’s a wall in the prepared cavity which is not extended to the external tooth surface
Pulpal wall is?
An internal wall that is towards the pulp, and covering the pulp, it may be both vertical and/or perpendicular to the long axis of the tooth
Axial wall is?
An internal wall which is parallel to the long axis of the tooth
The floor is?
A prepared cavity internal wall which is usually flat and perpendicular to the occlusal forces directed occlusogingivally
Ex: pulpal and gingival walls
Floors provide?
Stability seats for the restoration that distribute the stress in the tooth structures
Angles are?
The confluence of the walls
2 walls form?
A line angle
3 walls form?
A point angle
Cavosurface margin is formed by?
The junction of the external surface of the tooth and a prepared cavity wall
The need for restoration is to
Repair a tooth after destruction mostly from caries
The restoration may be required in all cavities so that the tooth can perform ?
Proper function
The restorative procedure primarily repairs ?
The damage caused by caries and other destructive processes
The purposes of cavity preparation are?
8:
1. Removal of all the defects of enamel, dentin, and cementum
2. Prevent recurrences of the disease
3. Avoid falling of the restorative material
4. Prevent the material from moving into the cavity
5. Prevent fracture of the remaining tooth
6. Prevent fracture of the restorative material
7. To allow the placement of the restorative material
8. Protect the dentin-pulp complex
Should all tissue altered by decay be removed?
No, defensive tertiary dentin
Extension for prevention means?
The placing of margins of preparations at areas that would be cleaned by the excursions of food during chewing, to prevent secondary caries
Do we always do extension for prevention?
No, depends on the material
Where is the recurrence of decay most commonly seen?
Margins of the fillings
Extension for retention means?
To do a preparation so that the sealing material can not leave the cavity
Does amalgam have chemical adhesion?
No, it has frictional retention, a certain expansion
What kind of adhesion does CR have?
Adhesive
Extension for supporting means?
To prevent the material from moving into the cavity, it should stay in the cavity without movement
Displacement of the material causes?
Marginal sealing mismatch and filtration
Extension for resistance of the tooth means?
Weakened areas are eliminated to prevent fracture of the tooth
Extension for resistance of the material means?
Preparations must allow adequate thickness and location of cavo surface margin in favorable areas to prevent fracture of the restorative material
What does “ to allow the placement of restorative material” mean?
Sometimes an area of the tooth is eliminated to facilite the filling
Extension for pulp protection means?
Protect the dentin-pulp complex, avoid iatrogenic factors and eliminate bacterial infections
How many line and point angles do classes II and IV have?
11, 6
How many line and point angles do classes I and V have?
8, 4
How many line and point angles does class III have?
6 , 3