■ ^^CIassV>	Cavity Preparation	
	\	
Cervical area
Predictable dirty place ^^^^
Nearness of gingiva - possibility^ its injury, bleeding, inflammation ^^^^^^
Flow of the sulcular liquid
i Difficulties with the maintenance of the dry field
Specific ordering of the hard dental tissues
Také into account
Access lntb<Qie Cavity
Elimination od the undermined enamel
Burs or diamonds (pear), tapered fissure bur
Separation of the gingiva- temporary fillin guttapercha, fermit, clip, zinkoxidsulfate cement, cavit, provimat).
Ablation of ingrown gingiva - surgical (scalpel, laser, high frequency current)
V.CIassAmalgam
• Posterior area
DetermjjTation of cavity borders an^^e^tention for
prevention
We do not follow Black's rules exactly! Gingival: axial dephth of 0,5 mm inside thi 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
Retention
» Box 0,75 - 1,25 mm deep, undercuts, coves (larger cavities)
Excavation oT^earious dentin
Round bur
Excavator
Filling
Portion of amalgam are condensed using a condensor (stamen) and finished using a spatula or a carver.
Class five^cpmposi'te
> Aesthetic reasons
Access lntb<Che Cavity
• Elimination od the undermined enamel
- Burs or diamonds (pear), tapered fiss||ebur
• 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!!!!
Determinationoicavity 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
Class five^eilasionomer
Cavity outside of enamel
^fopf rties
> Chemical fixation to tooth structure
> Fluoride release
> Favorable thermal expansion
> Aceptable aesthetics
Determinationoicavity borders
Cavity is limited on the caries defect only -no extention!!!!
The depth usually 1 mm
etention
> Box
> Chemical
Finishing of cavity borders
Fine diamond bur
Filling
> Conditioner 20 s
> Washing off
> Wet cavity
> Filling material
> Matrix
> Varnish
Sandwich
principle
Base of galsionomer - replace cnNthe lost dentin
Thin layer of composite - replace of the los enamel