Dental Unit lenka.roubalikova@tiscali.cz 2 Spitting box with amalgam separator Light Driving system Tray Chair lenka.roubalikova@tiscali.cz 3 Hoses - lower leading lenka.roubalikova@tiscali.cz 4 Hoses – uper leading lenka.roubalikova@tiscali.cz 5 -Spitter block -Suction -Amalgam separator Modules: Motor Turbine Air/water gun (syringe) Ultrasound Polymerization unit lenka.roubalikova@tiscali.cz 6 Instruments for preparation of cavities Hand instruments for cutting Two main materials: Stainless steel (loses keen edge) Carbon steel (corrode) Excavator Chisel- cleaver lenka.roubalikova@tiscali.cz lenka.roubalikova@tiscali.cz 7 Instruments for cavity preparation Power driven instruments for cutting - Rotary instruments Comon design characteristics lenka.roubalikova@tiscali.cz shank neck head lenka.roubalikova@tiscali.cz 8 Shank  The part that fits into the handpiece  Accepts the rotary motion from the  handpiece  Provides a bearing surface to control the  alignment and concentricity of the  instrument lenka.roubalikova@tiscali.cz 9 Straight handpiece shank  Simple cylinder  held in the handpiece in a metal chuck lenka.roubalikova@tiscali.cz 10 Latch angle handpiece shank  Shorter length – access to posterior regions Handpiece – contra angle, metal bur tube. The end of the instrument fits into D-shaped socket at the bottom of the bur tube. The instrument retained by a retaining latch that slides into the groove found at the shank end of the instruments. Low and medium speed lenka.roubalikova@tiscali.cz 11 Friction grip handpiece shank Smaller design, simple cylinder. Held in the handpiece by friction in plastic or metal chuck. lenka.roubalikova@tiscali.cz 12 Neck design Intermediate portion of an instrument that connects the head to the shank Tapered, shorter or longer. lenka.roubalikova@tiscali.cz lenka.roubalikova@tiscali.cz 13 Head design Burs – cut of steel or tungsten carbid Diamond (diamond burs)– covered with the diamond bort lenka.roubalikova@tiscali.cz lenka.roubalikova@tiscali.cz 14 Head design Burs classification systém Round Inverted cone Pear shaped Straight fisure Tapered fissure lenka.roubalikova@tiscali.cz lenka.roubalikova@tiscali.cz 15 Bur blade design  Rake face (towards the direction of cutting)  Clearence face Rake angle – slightly negative Edge angle – appr 90° Clearence angle Clearence face rounded or two surfaces. lenka.roubalikova@tiscali.cz 16 Head design Diamond classification system Round Inverted cone Pear shaped Cylinder Taper Lens Needle etc. The bur for handpiece – slow rpm Diamond lenka.roubalikova@tiscali.cz 19 Diamond abrasive instruments Diamond bort – small aharp particles in softer matrix. Cutting occurs at a large number of points. Metal blank Diamond powder Metallic bonding material lenka.roubalikova@tiscali.cz 20 Preparation speed  Low (slow) speeds – below 12.000 rpm  Medium or intermediate speeds 12.000 – 200.000 rpm  High or ultrahigh speeds above 200.000 rpm lenka.roubalikova@tiscali.cz 21 400.000 rpm lenka.roubalikova@tiscali.cz 22 1 : 1 as far as 40.000 rpm lenka.roubalikova@tiscali.cz 23 Red coded handpiece 1:4 až 1:5 as far as 160.000 – 200.000 rpm lenka.roubalikova@tiscali.cz 24 Green coded handpiece 2,7:1 7,4:1 lenka.roubalikova@tiscali.cz 25 Motors and gears Electromotors – maximum 40.000/min Airmotors – maximum 20.000/min Gearing to fast speed Gearing to slow speed Oscillation Blue code – gear 1:1 1:5 2,7 :1 or 7,4 :1 lenka.roubalikova@tiscali.cz 26 Blue and green coded handpiece lenka.roubalikova@tiscali.cz 27 Hanpieces combined 1:1 2:1 nerotuje lenka.roubalikova@tiscali.cz 28 Odontoblasts Predentin Dentin Dental pulp lenka.roubalikova@tiscali.cz 29 Preparation trauma  High temperature – heat  Pressure  Vibrations lenka.roubalikova@tiscali.cz 30 Preparation trauma  High temperature – heat: Water cooling (spray) Interrupt preparation Without cooling: only low speed. Protection of dentin wound  Preparation in dentin - dentin wound.  Treatment of the dentin wound: Base Subbase (indirect pulp capping) Adhesive systems (teching, priming, bonding) lenka.roubalikova@tiscali.cz 32 Indirect pulp capping Deep caries Probably changes in dental pulp Infection inside Calcium hydroxide influences the pulp through dentin Inflammation is healing New dentin is produced Class I. 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. 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 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. 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 no 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. Finishing and polishing  Fine grit diamond bur. Box  (1,5 – 2 mm Mistake Resistance  No undermined enamel, no close to the top of cusp than 1 mm Excavation of carious dentin  Ball (round) burs Low rpm – 3000/min Finishing and polishing Ohlazení - stěny nezešikmujeme!!! Jemný diamantovaný brousek (s červeným označením) – otáčky okolo 20 000/min. Final control Kontrola zrakem v dobrém osvětlení, vypláchnutí vodní sprayí a sušení. U kazů ve foramina coeca: Preparace v rozsahu ložiska Do dentinu Lze podsekřiviny Ohlazení okrajů Instruments  Preparation instruments  Filling instruments  Carvers  Burnishers Instruments  Preparation instruments - power driven Burs Diamonds Instruments  Preparation instruments - hand Chisel Excavator Amalgam gun Crucible Amalgam carrier Amalgam carrier Instruments  Filling instruments condensors and spatulas Condensor - stamen Condensor with straight front Condensor and burnisher - spatula combined Power driven condensor - stamen Special handpiece Burnisher - spatula Angular- trough edge trough face Burnisher – spatula, angular three face Instruments  Burnishers Ball condensor – used as a burnisher at most