Evaluation of the accuracy of inlayrestorations produced with a 3D printer fromdifferent dental resins with different curi̇ngtimes

Objective: The aim of this study is to examine the surface accuracy of inlay restorations produced with three different curing times from different permanent dental resins using a reverse engineering software program. Materials and methods: The mandibular first molar phantom tooth was scanned with an intraoral scanner and digitized. Inlay cavity and inlay restoration designs were prepared using a digital design program. The prepared inlay restoration design was transferred to a three-dimensional printer. Three different permanent dental resins (P-Crown V2 Ceramic, Varseo Smile Crown Plus, Varseo Smile Crown Plus, Saremco Print-Crowntec) were used to create 60 sample groups of each of three different permanent dental resins and 180 sample groups in total. Each group was divided into three subgroups according to 2000, 4000 and 6000 pulses curing times. The production parameters of the printer were adjusted in accordance with the company's instructions and printing processes were carried out. The samples separated from the printer table were first washed with 99% isopropyl alcohol and dried. Afterwards, curing processes were carried out with Otoflash G171 device under 1.2 bar nitrogen atmosphere. The cured specimens were scanned with an intraoral digital scanner and the digital data were transferred to the computer. The digital dimension of each sample was overlaid with the reference design and the surface accuracy was examined. The data obtained as a result of registration were analyzed with the help of SPSS v24.0 statistical program. vii Results: When the RMS (root mean square) values between the different permanent restoration resins were analyzed; a statistically significant difference was observed between all three resin groups at 6000 pulses. At 4000 pulses of curing, RMS values decreased in all groups. The lowest RMS values were observed in the Crowntec group, while the highest RMS values were found in the Senertek group. Conclusion: The surface accuracy of restorations produced with 3D printers in the same production protocol is affected by the type of permanent dental resin and different curing times. Keywords: 3D printing, dental resin, inlay, indirect restoration.