The Effect of Optical Conditioning of Preparations with Scan Spray on Preparation Form

Svrha rada: Za primjenu sustava CAD/CAM u ordinacijama dentalne medicine potrebno je odabrati sprej za skeniranje. Njegovom primjenom mijenja se prekrivena preparacija, što može nepovoljno utjecati na rubno zatvaranje i interno prianjanje restauracije. Zadaća ovog istraživanja bila je odrediti utjecaj spreja na preparacijsku formu procjenom morfologije i debljine triju različitih sprejeva za skeniranje. Materijali i metode: Određivala se površinska morfologija prekrivanja triju (A, B, C) različitih sprejeva za skeniranje uz pomoć konfokalnoga laserskog mikroskopa. Debljina sprejem nanesenog premaza mjerila se na staklenoj pločici i u simuliranim kliničkim uvjetima profilometrom i uređajem za digitalizaciju površine. Podaci su analizirani jednosmjernim testom ANOVA (α = .05). Rezultati: Konfokalni laserski mikroskop prikazao je grubu i nepravilnu sprejem pokrivenu površinu nakon uporabe svih sprejeva, te se od spreja A preko spreja B do spreja C broj malih zrnaca povećavao. Srednja debljina prekrivanja na staklenoj pločici iznosila je za sprej A 25,3 Μm, za B 18,9 Μm i za C 19,2 Μm. Statistički značajne razlike bile su između sprejeva A i B (p=0,017). U simuliranim kliničkim uvjetima srednja debljina prekrivanja iznosila je za sprej A 15,5 Μm, za B 15,0 Μm i za C 13,3 Μm. Razlika je bila statistički značajna samo između sprejeva A i C (p=0,033). Zaključak: Premazi nakon korištenja različitih sprejeva imali su drugačije površinske morfologije i različite debljine. Posljedično tome primjena spreja za skeniranje utječe i na konačnu CAD/CAM restauraciju, premda se kliničkim korištenjem postigla prihvatljiva debljina prekrivanja.Objective: CAD/CAM systems require scan spray for chairside sampling of tooth surfaces. However, this leads to alterations of the sprayed preparation and may affect marginal and internal adaption of the restoration. The aim of this study was to define the effect of scan spray on preparation form by evaluating the morphologies and the thicknesses of three different scan sprays. Materials and Methods: The surface morphology of the coatings of different scan sprays (A, B, C) was evaluated by use of a confocal laser scanning microscope. The thicknesses of spray coatings were measured on a glass plate as well as under simulated clinical conditions using a profilometer and a surface digitalisation device. The data were analysed by a 1-way ANOVA (α = .05). Results: The confocal laser scanning microscopy showed rough and irregular formed coating surfaces of all sprays, whereas an increasing numbers of small spray particles were seen from spray A over spray B to spray C. Mean coating thicknesses on the glass plate were: spray A 25.3 Μm, spray B 18.9 Μm and spray C 19.2 Μm. Significant differences were detected between spray A and B (P = .017). Under simulated clinical conditions median coating thicknesses were: spray A 15.5 Μm, spray B 15.0 Μm and spray C 13.3 Μm. A statistically significant difference could be detected only between spray A and C (P = .033). Conclusions: The coatings of the used scan spray systems showed different surface morphologies and exhibited different thicknesses. Consequently, the application of scan sprays affects the precision of the final CAD/CAM restorations. However, the scan sprays under investigation showed acceptable coating thicknesses for clinical use