Purpose: To evaluate and compare the mechanical properties and ceramic bond of additively manufactured and milled dental zirconia materials. Materials and Methods: Disc (r = 10 mm, h = 2 mm) and bar (25 × 4 × 1. 2 mm) shaped milled (M group) (Nacera Pearl; Doceram) and additively manufactured (AM group) (NanoParticle Jetting; XJet, Carmel 1400) zirconia specimens were prepared for 2 experimental groups. Ceramic was applied to the disc specimens (h = 4 mm, r = 6 mm) (n = 9) and their shear bond strength (SBS) was measured. The surface morphology of disc specimens was analyzed with a scanning electron microscope (SEM). The Vickers microhardness (Vh), surface roughness (Ra), and three-point flexural strength (FS) of bar specimens (n = 9) were measured. Results were statistically analyzed with Mann-Whitney U-test (α = 0.05). Results: Significant differences were found in FS and Vh values of the M and AM groups. M group (1501.4 ± 60.1 HV1) showed a significantly higher Vh value than the AM group (1169.2 ± 48.4 HV1) (p < 0.001). FS of the M group (1287.5 ± 115.2 MPa) exhibited significantly high value than the AM (1030.0 ± 29.2 Mpa) group (p < 0.001). Statistically, no significant differences were seen in SBS and Ra values of the M and AM groups. Conclusion: Within the limitations of this in vitro study, the manufacturing technique affected the mechanical properties of the zirconia materials. AM zirconia material showed lower Vh and FS values than M zirconia. Additionally AM zirconia demonstrated adequate bond strength with dental ceramic.

Coating zirconia and alumina surfaces with chitosan is an efficient surface modification for increasing biocompatibility and bioactivity of these materials in vitro.

The aim of this study was to obtain a biocompatible and antimicrobial implant surface by coating Ti6Al4V with chitosan which can be used to create a smooth transmucosal region for a faster and better wound healing and an increased bioactivity. Ti6Al4V plates were first abraded and ultrasonically cleaned and then coated with chitosan. In order to simulate the conditions of an oral environment, a group of coated plates were treated in a thermocycle apparatus. The coatings were evaluated with SEM, EDS, XRD and FTIR spectroscopy. The fibroblastic cell behavior was determined using HGF-1 cells. P. gingivalis was used to assess the effectiveness of chitosan as an antimicrobial coating. It can be said that the Ti6Al4V plates were successfully coated with chitosan, indicated by the presence of the C, H and O elements in the EDS results. There were no significant differences between the XRD patterns of the coated and uncoated plates; however, the characteristic bands of chitosan were observed in the FTIR patterns of both the coated and aged samples. The fibroblast-cell attachment and proliferation were enhanced while the bacterial proliferation was inhibited by the chitosan coating. Chitosan was shown to be a biologically useful material that can be used as the coating material for transmucosal regions of dental implants. Keywords: chitosan coating, dental implants, Ti6Al4V, HGF-1, P. gingivalis Namen te {tudije je bil dobiti biokompatibilno in antimikrobno povr{ino implantata z nanosom hitozana na Ti6Al4V, ki je primeren za gladko transmukozno podro~je, za hitrej{e in bolj{e celjenje ran ter pove~ano bioaktivnost. Pri plo{~ah Ti6Al4V je bila najprej pove~ana hrapavost, nato so bile o~i{~ene z ultrazvokom, potem pa je bil nanesen hitozan. Da bi simulirali razmere v ustih, je bila skupina plo{~obdelana v napravi za termocikliranje. Nanosi so bili ocenjeni s SEM-, EDS-, XRD-in FTIR-spektroskopijo. Vedenje celic fibroblastov je bilo dolo~eno z uporabo celic HGF-1. P. gingivalis je bil uporabljen za oceno u~inkovitosti hitozana kot protimikrobnega nanosa. Lahko trdimo, da so bile plo{~e Ti6Al4V uspe{no prekrite s hitozanom, kar potrjuje prisotnost elementov C, H in O v EDS-rezultatih. Ni bilo opa`ene ve~je razlike pri rentgenski analizi vzorcev z nanosom in brez nanosa, vendar so bili opa`eni karakteristi~ni signali hitozana pri FTIR-analizi vzorcev tako pri vzorcih z nanosom kot tudi pri staranih vzorcih. Oprijemanje in {irjenje fibroblasti~nih celic je bilo pospe{eno, medtem ko je nanos hitozana zaviral {irjenje bakterij. Pokazalo se je, da je hitozan biolo{ko koristen material, ki ga je mogo~e uporabiti za nanos na transmukozna podro~ja dentalnih implantatov.

their well-being and appearance. Emotional effects of tooth loss on people and their daily lives are well established (3). Several studies report significant associations between tooth loss and the scores of unfavorable oral health-related quality of life (4). Comorbid depression and anxiety are linked to the increased number of tooth loss and it has been suggested that tooth loss may deteriorate depression and anxiety (5).