lenka.roubalikova@ti scali.cz 1 ClassificationClassification accacc. to. to BlackBlack Class I. Pit and fissure caries lenka.roubalikova@ti scali.cz 2 ClassificationClassification accacc. to. to BlackBlack Class II. Proximal surfaces in premolars and molars lenka.roubalikova@ti scali.cz 3 ClassificationClassification accacc. to. to BlackBlack Class III. Proximal surfaces of incisors and canines without lost any part if incisal edge lenka.roubalikova@ti scali.cz 4 ClassificationClassification accacc. to. to BlackBlack Class IV. Proximal surfaces of incisors and canines with lost an incisal ridge lenka.roubalikova@ti scali.cz 5 ClassificationClassification accacc. to. to BlackBlack Class V. cervical lesions lenka.roubalikova@ti scali.cz 6 PPreparationreparation ofof cavitiescavities BasicBasic rulesrules Access to the cavity Outlines – cavosurface margin (extention for prevention) Principles of retention Principles of resistance Excavation of carious dentin Preparation of borders – finishing Control lenka.roubalikova@ti scali.cz 7 ProtectionProtection ofof dentindentin woundwound Dentin wound should be covered – protection of dental pulp against irritation Physicial -thermal -osmotic Chemical Combination lenka.roubalikova@ti scali.cz 8 ProtectionProtection ofof dentindentin woundwound Isolation Filling (small cavities) Base (moderate – large cavities- depth 2mm and more approx.) Adhesive systems ( composite materials) lenka.roubalikova@ti scali.cz 9 FillingFilling Filling replaces lost hard dental tissue anatomically and functionally Always different properties in comparison to hard dental tissues. lenka.roubalikova@ti scali.cz 10 Base is made usually of zinkoxidphosphate cement It is placed only on pulpal wall PreparationPreparation ofof thethe cavitycavity I.I.stst classclass accacc. to. to BlackBlack Cavities in fissures and pits (Occlusal surfaces of premolars and molars and in f. coeca) F. Coeca: buccal surfaces of lower molars, Palatal surfaces of lower molars, palatal surfaces of upper incisors (mostly lateral) Morphology of fissures Biofilm Caries All pit and fissure restorations (fillings) They are assigned in to three groups. R. on occlusal surface of premolars and molars R. in foramina coeca – usually on occlusal two thirds of the facial and lingual surfaces of molars. R.on lingual surface of maxillary incisors. MaterialsMaterials: Amalgam,: Amalgam, compositecomposite.. Amalgam:Amalgam: PertinentPertinent materialmaterial qualitiesqualities andand propetiespropeties StrengthStrength LongevityLongevity EasEasyy ofof useuse ClinicallyClinically provenproven sucesssucess Access toAccess to thethe cavitycavity From the occlusal surface using the fissure bur (or diamond burs, see below). OutlineOutline Ideal outline includes all occlusal pits and fissures. If crista transversa (1st lower premolar)or obliqua (1st and 2nd upper molar)are not affected, it is strongly recommended no to prepare them. Cavosurface margin is in ½ distance between bottom of the fissure and the cuso Crista obliqua M1 M2 M3 M1 M2 M3 Upper jaw Lower jaw Molars Premolars Crista transversa Lower P1 RetentionRetention principlesprinciples Prepare the box – the bottom is in dentin Undercuts can be prepared, the proximal ridges must not be weakened! RetentionRetention principlesprinciples Box in dentin Box (Box (rememberremember roundedrounded edgesedges)) BoxBox withwith undercutundercut ResistanceResistance principlesprinciples Box – space for amalgam 1,5 – 2 mm Keep the facial and lingual margin extensions as minimal as possible between the central groove and the cusp tips. Max 1/2 Extending the outline to include fissures, thereby placing the margins on relatively smooth sound tooth structure. Minimally extending into the marginal ridge without removing dentinal support. Never leave the enamel undermined All corners are round, the bottom smooth. RemovalRemoval ofof cariouscarious,, infectedinfected, dentin, dentin Spoon excavator or a slowly revolving , round carbid bur of appropriate size. The pulpal wall and pulp chamber FinishingFinishing andand polishingpolishing Fine grit diamond bur. Final control Wash and dry the cavity Check the praparation in good illumination Preparation is limited on the caries lesion 1,5 mm deep Undercuts can be prepared If the caries undermined the occlusa enamel, prepare the cavity on the occlusal surface.