Preclinical Dentistry Dental Caries Non carious lesions: trauma, erosion, abrasion, wedge shaped defects Lenka Roubalíková Understanding dental caries pulp chamber^ root c mal "*" crown neck root Dental Tissues Dental caries time sugar Dental Caries Infectious microbiological disease of the teeth that results in localized dissolution and destruction of the calcified tissues Biofilm - Dental Plaque A gelatinous mass of bacteria adhering to the tooth surface. I No shedding Dental biofilm Adhesion Colonisation Maturation Sugar Fermentable (mono-, di- tri- sacharides) Sucrose, glucose, lactose —► Acids L >,. jjŕ 1 Demineralization Non - cavitated lesion Time Cavitated lesion ► • Plaque formation • Microbial source • Mineral source • Microbial clearence • Buffer capacity iva Predictable dirty places Caries risk places • Pits and fissures • Proximal surfaces • Cervical area No self cleaning Predictable clean places • Cusps • Proximal ridge • Incisal edge • Buccal or oral surface upon the maximal convexity • Proximal surface upon tje Self cleaning • Surface caries (caries superficialis) • Middle caries (caries media) • Caries close to pulp (caries pulpae proxima) • Caries penetrating into the pulp (caries ad pulpám penetrans) c 1 J jr C 1 J c 1 J jr Caries - Topography • Coronal caries • Root surface caries • Enamel caries • Dentin caries • Cementům caries Caries > Acute >Chronic > Arrested A > Acc to its history j Penetrating Undermining Primary caries Secondary caries Recurrent caries Preparation Instrumental treatment Remove caries Leave the rest of the dental tissues - to be restored - to be resistent against the bite forces - to be prevented against the recurrent caries (Black 1914) Classification of cavities according to Black Class I. Caries in fissures and pits - occlusal surfaces of premolars and molars Class II. Proximal surfaces of molars and premolars Class III. Proximal surfaces of incisors and canines without loss of the incisal edge Class IV Proximal surfaces of incisors and canines with the loss of incisal edge Class V. Cervical area Charting and records the most important notation Caries / Filling P Tooth for extraction X Extracted tooth + Crown Pontic Tooth in removable denture 0 lenka.roubalikova@tiscali.cz Instruments for investigation -investigative instruments Explorer (probe): Sharp, straight or bow shaped: Caries detection - Ight motion without any pressure: dental surfaces, fillings. Periodontal explorer (probe): not sharp, calibrated, investigation of periodontal pockets lenka.roubalikova@tiscali.cz Instruments for investigation -investigative instruments >Mirror - flat or concave >To see less available regions >To illuminate >To move off soft tissues (cheeks, tongue etc.) lenka.roubalikova@tiscali.cz 42 Instruments for investigation -investigative instruments Tweezer To grip various instruments and supplies. lenka.roubalikova@tiscali.cz Instruments for cavity preparation Hand instruments for cutting Two main materials: Stainless steel (loses keen edge) Carbon steel (corrode) Excavator Chisel- cleaver lenka.roubalikova@tiscali.cz Preparation instruments Power driven instruments for cutting - Rotary instruments Comon design characteristics lenka.roubalikova@tiscali.cz 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 Straight handpiece shank >Simple cylinder > held in the handpiece in a metal chuck 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. Friction grip handpiece shank Smaller design, simple cylinder. Held in the handpiece by friction in plastic or metal chuck. lenka.roubalikova@tiscali.cz Neck design Intermediate portion of an instrument that connects the head to the shak Tapered, shorter or longer. lenka.roubalikova@tiscali.cz Head design Burs - cut of steel or tungsten carbid Diamond (diamond burs)- covered with the diamond bort lenka.roubalikova@tiscali.cz Head design Burs classification systém Round Inverted cone Pear shaped Straight fisure Tapered fissure lenka.roubalikova@tiscali.cz to Inverted Pear- Straight cone shaped fissure j 7-34 Basic bur head shares. 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. Head design Diamond classification systém Round Inverted cone Pear shaped Cylinder Taper Lens Needle etc. "™M lenka.roubalikova@tiscali.cz 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 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 ■■■■■■■■■■■■■■■■m y ^oíCOfs Speed increasing gear 1 Green ring: 2,7:1 2 Green rings: 7,4:1 Speed decreasing gear Spitting box with amalgam separator Light Driving system Tray Hoses lower leading Hoses - uper leading Cavity preparation > Power driven >Hand 400.000 rpm Electromotors - maximum 40.000/min Airmotors - maximum 20.000/min Gearing to fast speed red Gearing to slow speed green Oscillation yellow 1 : 1 as far as 40.000 rpm Red coded handpiece ■■■■■■■■ y wmmaammmmmm^mmmmm^tmammmmmmammm^t^n 1:4 až 1:5 as far as 160.000 - 200.000 rpm Green coded - slow 2,7:1 7,4:1 Blue and green coded handpiece Hanpieces combined lil l3r3=J3 2:1 r. B^= H No rotatic^^: 31 169375 Burs ISO 6360 Diamond í _________________________________._.^_______^___ Chisel -for enamel Cleaver Chisel for enamel Excavator Filling instruments Burnisher-plane Angular- trough edge trough face Burnisher - angular three face Condensor and burnisher Amalgam carrier Condensor for amalgam i Condensor for guttaprecha - hoof o j? Ball condensor ^ iMiin Condensor -stamen Fosterflagg Frahm Carver: Discoid - Cleoid