Possible errors during the optical impression procedure

Abstract

Introduction. Modern technologies offer a range of benefits and significantly improve specific therapeutic procedures in dentistry. However, despite gaining experience and training there are still some mistakes in their implementation. The aim of this study was to describe the most common errors during intraoral scanning, 'optical impression' procedure, during CAD-CAM technology for production of dental restorations. Material and Methods. Cerec® 3D CAD-CAM system for one visit tooth reconstruction by inlays, onlays, endocrowns, half and complete crowns and veneers from the ceramic material was used in the study. Results. Analysis included 1564 reconstruction during 5 years. The most common causes of errors performing optical impression were the result of: improper preparation of teeth, the instability of the scanner in the mouth of the patient, incorrect position and angle of the scanner to the object scanning, contrast spray applied in uneven layer, the presence of fluid in the region scan, the presence of artifacts in the region gingival sulcus. Conclusion. Optical impression is faster procedure than conventional impression, but technologically sensitive. The most frequent errors are: improper handling of the scanner, inadequate tooth preparation, irregular powder application on the tooth and irregular use in the gingival sulcus.

Uvod. Savremene tehnologije u stomatologiji imaju niz prednosti i značajno unapređuju pojedine terapijske postupke. Međutim, i pored sticanja i usavršavanja određenih iskustava, javljaju se greške u njihovoj primeni. Cilj rada je bio da se prikažu najčešće greške prilikom postupka optičkog intraoralnog skeniranja (tzv. otiskivanja) kod CAD-CAM tehnologije izrade zubnih nadoknada. Materijal i metode rada. U radu je korišćen Cerec ® 3D CAD-CAM sistem za jednoseansnu rekonstrukciji zuba izradom inleja, onleja, endokruna, delimičnih i celih kruna, venira, najčešće izrađenih od keramičkih materijala. Rezultati. Analiza je obuhvatila 1.564 restauracije tokom petogodišnjeg rada. Najčešći uzroci grešaka kod optičkog otiskivanja bili su posledica nepravilne preparacije zuba, nestabilnosti skenera u ustima pacijenta, nepravilna pozicija i ugao skenera u odnosu na objekat snimanja, kontrastni sprej nanesen u neravnomernom sloju, zastupljenost tečnosti u regionu skeniranja i artefakta u regionu gingivalnog sulkusa. Zaključak. Optičko intraoralno skeniranje je jednostavniji i brži princip otiskivanja od konvencionalnog postupka, ali je tehnološki osetljiviji. Najčešće greške prilikom optičkog otiskivanja su: nepravilno rukovanje skenerom, neadekvatna priprema zuba, nepravilno nanošenje praha za matiranje površina i nepravilna priprema regiona gingivalnog sulkusa.