Composites in posterior teeth All pit and fissure restorations. 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. T r v a n l i v o i s t Longevity of fillings Indications Moderate to large restorations Restorations that are not in highly aesthetics areas Restorations that have heavy occlusal contacts Restorations that cannot be well isolated Restorations that extend onto the root surface Foundations Abutmjent teeth for removable partioal dentures Temporary or caries control restorations. Contraindications Aesthetically prominent areas of posterior teeth Small moderate classes I. that can be well isolated Materials: Amalgam, composite. Amalgam: Pertinent material qualities and propeties Strength Longevity Ease of use Clinically proven sucess Clinical technique From the occlusal surface using the fissure bur (or diamond burs, see below). Outline Ideal outline includes all occlusal pits and fissures. If crista transversa od obliqua are no affected, it is recommended not to prepare them. Resistance principles Keep the facial and lingual margin extensionsas minimal as possible between the central groove and the cusp tips. Extending the outline to include fissures, thereby placing the margins on relatively smooth sopund tooth structure. Minimally extending into the marginal ridge without removing dentinal support. Eliminating a weak wall of enamel by joining teo outlines that come close together Enamel. – Nevel leave the enamel undermined All corners are round, the bottom smooth. Retention principles Prepare the box – the bottom is in dentin Undercuts can be prepared, the proximal ridges must not be weakened! Removal of carious, infected, dentin and remaining defective enamel. Spoon excavator or a slowly revolving , round carbid bur of appropriate size. Indications Aesthetically prominent areas of posterior teeth Small - moderate classes I. that can be well isolated Good level of oral hygiene is necessary Contraindications Moderate to large restorations Restorations that are not in highly aesthetics areas Restorations that have heavy occlusal contacts Restorations that cannot be well isolated Restorations that extend onto the root surface Abutment teeth for removable partioal dentures Temporary or caries control restorations. Materials: Amalgam, composite. Amalgam: Pertinent material qualities and propeties Strength Longevity Ease of use Clinically proven sucess Clinical technique From the occlusal surface using the fissure bur (or diamond burs) Outline Outline includes the caries lesion only Retention principles Prepare the box or deep dish – the bottom is in dentin Do not prepare any undercuts! Do not bevel enamel, finish the border with diamond bur inly. Removal of carious, infected, dentin and remaining defective enamel. Spoon excavator or a slowly revolving , round carbid bur of appropriate size. Postoperative sensitivity ditching marginal discoloration gap cracks Versluis 2000 Secondary caries Polymerization shrinkage Polymerization shrinkage Surface of adhesion/free surface of the filling 1/1 and less is optimal C - factor 5 2 1 Postoperative sensitivity ditching marginal discoloration gap cracks Versluis 2000 Secondary caries lroubalikova@gmail.com 29 Monomer Polymer Light Polymerization 30 Pre –gel Gel point Post -gel - Chemicky iniciovaný kompozit 434343 43mm 42mm Fotokompozit 3,2mm 57 mm 3mm 8,5mm Fotokompozit 102mm 48mm Forces of polymerization shrinkage depend on - Composite material (content of filler) - Geometry of the cavity (C-factor) - Placement of the composite - Mode of polymerization Forces of polymerization shrinkage depend on (polymerization stress) Composite material (content of filler) High content of the filler causes bigger stress Flowable composites – low stress Forces of polymerization shrinkage depend on Geometry of the cavity (C-factor) Polymerization shrinkage Polymerization shrinkage Surface of adhesion/free surface of the filling 1/1 and less is optimal C - factor 5 2 1 Postoperative sensitivity ditching marginal discoloration gap cracks Versluis 2000 Secondary caries Forces of polymerization shrinkage depend on - Placement of the composite: - Create the first layer thin, flowable can be used - Place th material in increments with respect of the C-factor of each layer 1 2 3 Placement of the material Forces of polymerization shrinkage depend on - Mode of polymerization Phases - Pre-gel - G-point - Post -gel Monomer Light Polymerization Polymer Pre –gel Gel Post -gel Pre gel phase should be long – soft start !!!! Marginal adaptation Placement of composite material Dry operating field Adhesive systems Flow materiály - význam 1. Vyrovnání zátěže (protistresové vlastnosti) 2. Vyblokování podsekřivin 3. Adaptace ke stěnám 4. Estetické důvody 5. Ochrana adheziva Temperovaný kompozit = konfigurační faktor Plocha adheze / volný povrch výplně Adhesives Acid etching technique Selfetching adhesive systems Adhesives Acid etching technique Etching Washing Priming Bonding Adhesives Selfetching adhesive systems Priming Bonding Adhesives Active and passive bonding Active – rubbing with microbrush Passive – without any rubbing Adhesive preparation in a fissure Adhesive preparation Preparation of enamel borders Preparation 45° Next to cusp 50-60°, Preparation 30 - 40° ? Cervical borders In enamel No bevel Cervical borders In dentin Interproximal borders Yes No Preparation technique Oscillating instruments Minikavity Otevírání fissur Composite filling class II. Contact point Contact point Contact area Class II. and contact point Matrix band + matrix retainer - Metal band - Plastic band (polyester) Without matrix retainer Sectional matrices with separator Sedelmayer Adhezivní slotová preparace Approximal Caries Approximal Caries Tunnel preparation Success? Low caries risk Special smal instruments Magnification BW post op