Class V. Cavity Preparation Anatomical x clinical crown Anatomical crown - cementum- enamel junction • Clinical crown - gingival border • Cervical area • Predictable dirty place • Nearness of gingiva - possibility of 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 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.CIass Amalgam Posterior area • 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 Incisal border Mesial snd dista border Gingival border Okluzální okraj kavity Pod maximální H konvexitouzubu |Mesiální|| a distálnífl okraj kavity Do axiálních | hran lili Gingivální okraj kavityH Pod okraj gingivyi ale i supragingiválně 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 condensor (stamen) and finished using r spatula or a carver. • a Class five - composite > Aesthetic reasons 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 — 2 mm wide and the angle 45° Cementum: only finishing with the fine diamond bur. 1 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 - alasionomer 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 :etention > 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 Composite Base Bond: GIC - Tooth Chemical Composite - Tooth Micromechanical Composite - GIC Micromechanica B.