Class V. Cavity Preparation
Characteristic
 Cervical defects
Anatomical x Clinical crown
Anatomical x clinical crown
 Anatomical crown - cementum- enamel junction
 Clinical crown – gingival border
anatomická x klinická korunka
Cervical area
 Caries danger area
 Gingiva - possibility of its injury,
bleeding.
 Flow of the sulcular liquid
 Specific ordering of the hard dental tissues
Difficulties with the maintenance of the dry field
Také into account
Ordering of the dental tissues
On the surface can be
Enamel
Cementum
Dentin
Risk of opening of
the pulp chamber
Access Into The Cavity
 Elimination od the undermined enamel
- Burs or diamonds (pear), tapered fissure bur
 Separation of the gingiva– temporary filling
guttapercha, fermit, clip, zinkoxidsulfate
cement, cavit, provimat).
 Ablation of ingrown gingiva – surgical
(scalpel, laser, high frequency current)
V.Class Amalgam
 Posterior area
Determination of cavity
borders and extention for
prevention
We do not follow Black´s rules exactly!
Gingival: axial dephth of 0,5 mm inside the
DEJ.
Extention of the preparation incisally,
gingivally, mesially and distally untill the
cavosurface margins are positioned in sound dental
structure. Total dephth: 1 – 1.25 mm. If on root
surface -0,75 mm
Gingival border
Mesial
snd distal
border
Incisal border
Gingival border
mesial and distal
border
Occlusal border
Retention
 Box 0,75 – 1,25 mm deep, undercuts,
coves (larger cavities)
Resistance
Elastic deformation during the biting
Excavation of carious dentin
Round bur
Excavator
Finishing of cavity borders
 Fine diamond bur of a chisel
Filling
 Portion of amalgam are condensed using a
condensor (stamen) and finished using a
spatula or a carver.
Class five - composïte
 Aesthetic reasons
Contraindication of composites
 Bad hagiene
 Subgingival cavities
 Root caries (outside of enamel)
Access Into The Cavity
 Elimination od the undermined enamel
- Burs or diamonds (pear), tapered fissure bur
 Separation of the gingiva– temporary filling
guttapercha, fermit, clip, zinkoxidsulfate
cement, cavit, provimat).
 Ablation of ingrown gingiva – surgical
(scalpel, laser, high frequency current)
Composite must not be subgingival!!!!
Determination of cavity borders
Cavity is limited on the caries defect only –
no extention!!!!
The depth usually 1 mm
Retention
 Micromechanical retention
Enamel: Retentive border – 1 – 2 mm wide
and the angle 45°
Cementum: only finishing with the fine
diamond bur.
Retention
Retentive border:
- removing of the aprismatic enamel
– better condition for micromechanical retention
- better aesthetics
Retention
Acid etching (phosphoric acid): 30 s dentin,
30 s enamel
Rinsing (washing off) 30s
Priming, bonding, light curing.
Filling
Spatula
Matrix
- Polyester strip, wooden wedges
- Special cervical matrix
Matrix
Anatomical form
Class five - glasionomer
 Cavity outside of enamel
Properties
 Chemical fixation to tooth structure
 Fluoride release
 Favorable thermal expansion
 Aceptable aesthetics
Determination of cavity borders
Cavity is limited on the caries defect only –
no extention!!!!
The depth usually 1 mm
Retention
 Box
 Chemical
Finishing of cavity borders
Fine diamond bur
Filling
 Conditioner 20 s
 Washing off
 Wet cavity
 Filling material
 Matrix
 Varnish
Class V. – Sandwich
principle
Base of galsionomer – replace of the lost
dentin
Thin layer of composite – replace of the lost
enamel
Base
Composite
Bond:
GIC - Tooth
Chemical
Composite – Tooth
Micromechanical
Composite - GIC
Micromechanical