Radiography Radiography • Roentgen tube – x- ray tube: Cathode – Anode – Tension Catode (heated) - Electrons – go against Anode – brake - x ray originates Radiography • Imaging method completing clinical examination of patients Radiography Principle: X- rays going through various materials (tissues) are absorbed – image on the film (a special suspension AgBr – silver bromide) Roentgen tube X ray tube Anode Cathode wolfram (tungsten) filament inside (heated – brought to white heat) Focus – made of wolfram Extraoral and intraoral radiography • Extraoral: The film is placed outside of oral cavity - OPG (orthopantomography) - Teleradiography - Special projections of a skull (posteriorly – anteriorly) - Half axial - Side projection (TMJ,mandible) - CT Extraoral and intraoral radiography Intraoral – the film is placed into the oral Cavity – a special x-ray apparatus. - Teeth - Alveolar bone - Periodontal space - Fillings - Caries - Level of endodontic treatment OPG Side Posteriorly-anteriorly Posteriorly-anteriorly Half axial CT OPG Half axial Posteriotrly-anteriorly Side CT CT Intraoral radiography Film or sensor placed in oral cavity Special apparatus - Teeth - Alveolar bone - Periodontal space - Fillings - Caries - Impacted teeth - Level of endodontic treatment Position of the tubus • In vertical plane • In horizontal plane In vertical plane Parallel technique Film or sensor in a special holder Parallel to long axis of teeth Vertikální zastavení správné Velikost obrázku odpovídá skutečnosti – Snímek je ISOMETRICKÝ Vertikální zastavení nesprávné the picture of the tooth is smaller– hypometric or the picture of the tooth is bigger than the tooth - hypermetric If parallel technique is not possible The technique of isometric radiogram Technique of halving angle – isometric radiogram The x-ray beam Angle between the beam and axis of the angle The long axis of the tooth The tooth The angle betwen the long axis of the tootn and the film Film Alveolar bone and surrounding tissues The axis of the angle In horizontal plane Hypometric and hypermetric picture Central beam goes perpendiculary on the tooth Hypermetric picture – the picture is bigger – central beam goes perpendiculary to the film paprsek goes perpendiculary to the film. Hypometric – the picture is smaller The tubus can have vairous position • Apical projection: the central beam goes through the apex area • Periodontal projection: the central beam goes through the uper third of the root • Coronal projection: the central beam goes through the crown. Marginal – limbal position (projection) Apical position - projection Orthoradial and excentric projektion • Orthoradial – the central beam goes parallel to interdental septa • Excentric– the central beam goes from distal or mesial side. Bitewing Fiml or sensor is in a special holder, patien bites into Tje central beam goes parallel to interdental septa Crowns of teeth are well seen – good for early diagnosis of dental caries Principle of imaging • Irradiation is absorbed in various materials esp. in hard tissues. Accc to amount of absorbed irradiation radioopacity or radiolucency can be seen. Radiolucency – dark Radioopacity - white • Rtg status LR i.o. LR LR OPG radioopacity radiolucency CBCT