Class II. cavity preparation Defects affecting one or bot proximal surfaces of posterior teeth. Symptoms > Increased sensitivity (cold, sweei > Retention of food open - the e > Bite sensitivity (when carious lesion is open lroubal@med.muni.cz 2 Diagnosis > Vi > Transillumination > Radiography lroubal@med.muni.cz 3 lroubal@med.muni.cz ľ Preparation - amalgam rules > Slot preparation t ... , : . / \ • i > Large preparation — cusp(s) invoivea Preoaration - adhesive materials > Conventional preparation for composites > Adhesive slot > Tunnel preparation lroubal@med.muni.cz Conventional preparation Isthmus Access to the cavity occiu Through the undermined enamel Separation using wooden wedges is useful lroubal@med.muni.cz Pre op Pr Cavosurface margin Axial wedges Under the free gingiva Occlusal Class I. cavity preparation lroubal@med.muni.cz Retention > Occlusal cavity surface ccl > Undercuts > Grooves lroubal@med.muni.cz Axial walls are divergent in the gingival direction Verical and horizontal grooves 21 Resistance o undermined enam > No sharp wed > Isthmus is 1/3 — 1/4 intercuspal distance > Angle between axial and gingival wall: 90°, or 85° > Width of gingival wall is 1 mm at least > Thickness of the filling 2 — 4 mm (4mm cusp replacing) lroubal@med.muni.cz 22 Excavation of carious dentin Round bur (ball) or excavator El (Caries Detector, Kuraray, Japonsko; Caries Marker, VOCO,Německo) lroubal@med.muni.cz 24 Finishing of cavity walls > Red coded diamond bur gingival wall (if in e lroubal@med.muni.cz lroubal@med.muni.cz 27 Cavity control > Goog light lroubal@med.muni.cz Isthmus Matrix placement lyi is to be restore he objective Provide proper contact Provide proper contour Confine the restorative material Reduce the amount of excess material urf lroubal@med.muni.cz Matrices — matrix band, matrix retainer > Ivory I retainer Ivory > Hawe Neos retainer Ivory 8 > Toff lroubal@med.muni.cz Wedges dges - tighten the matrix band o the compression of the - separate the teeth lroubal@med.muni.cz Wedging > s: the gingival margin — 0,5, - 1 mm 5^5 > Tighten the matrix, check it with prob > Place a wedge > Turn the retainer % counterclockwise > Contour the band lroubal@med.muni.cz 35 Condensation of amalgam ondensor — S traig Power driven condensation lroubal@med.muni.cz Instruments lroubal@med.muni.cz 56