Effect of Different Surface Treatments Applied to Short Zirconia and Titanium Abutments.

PURPOSE: The aim of this study was to compare the effect of different surface treatments applied to short titanium and zirconia abutments on the bond strength of single-unit zirconia crowns. MATERIALS AND METHODS: Sixty titanium abutments were shortened to 3 mm in length, fixed to analogs, and embedded in acrylic blocks. Three-dimensional views of abutments were obtained by scanning; then, zirconia abutments and copings were produced. The samples, which included titanium (n = 60) and zirconia (n = 60) abutments, were divided into five different groups (n = 12), and surface treatments were carried out; 1.5-W and 3-W Er,Cr:YSGG laser treatment, AL2O3 sandblasting, and tribochemical silica coating were applied to the groups, and the control group had no surface treatment. Copings were cemented to the samples with self-adhesive resin cement. The samples were then subjected to the pull-out test, and the results were processed via statistical analysis. RESULTS: There was a significant difference between the titanium and zirconia groups (P < .001). The mean bond strength values of the titanium samples were higher than those of the zirconia samples. The tribochemical silica coating gave a higher bond strength than the other treatments when applied to titanium abutments. For the zirconia abutments, the 1.5-W laser treatment, 3-W laser treatment, tribochemical silica coating, and Al2O3 sandblasting groups differed significantly from the control group; however, they were not significantly different from each other. CONCLUSION: The bond strength of zirconia crowns to short titanium and zirconia abutments increases with surface treatments. Furthermore, the surface treatments were more effective in increasing the bond strength for the titanium abutments than for the zirconia abutments.

The effects of different surface treatments on the shear bond strengths of two dual-cure resin cements to CAD/CAM restorative materials.

PURPOSE: The aim of the present study was to investigate the effects of surface treatments on the bond strengths between polymer-containing restorative materials and two dual-cure resin cements. MATERIALS AND METHODS: In the present study, rectangular samples prepared from Lava Ultimate (LU) and Vita Enamic (VE) blocks were used. The specimen surfaces were treated using CoJet sandblasting, 50 µm Al2O3 sandblasting, % 9 HF (hydrofluoric) acid, ER,Cr:YSGG laser treatment, and Z-Prime. Dual-cure resin cements (TheraCem and 3M RelyX U 200) were applied on each specimen's treated surface. A micro-tensile device was used to evaluate shear bond strength. Statistical analysis was performed using the SAS 9.4v3. RESULTS: While the bond strength using TheraCem with LU or VE was not statistically significant (P=.164), the bond strength using U200 with VE was statistically significant (P=.006). In the TheraCem applied VE groups, Z-Prime and HF acid were statistically different from CoJet, Laser, and Sandblast groups. In comparison of TheraCem used LU group, there was a statistically significant difference between HF acid and other surface treatments. CONCLUSION: The bonding performance between the restorative materials and cements were material type-dependent and surface treatment had a large effect on the bond strength. Within the limitations of the study, the use of both U200 and TheraCem may be suggested if Z-prime was applied to intaglio surfaces of VE. The cementation of LU using TheraCem is suitable after HF acid conditioning of the restoration surfaces.

Cognitive performance of primary open-angle glaucoma and normal-tension glaucoma patients.

PURPOSE: To assess cognitive performance differences among primary open-angle glaucoma (POAG) patients, normal-tension glaucoma (NTG) patients, and healthy control (C) subjects. METHODS: A total of 60 participants (20 POAG, 20 NTG, and 20 C subjects) were included in this study. A detailed ophthalmologic examination was performed on all participants. A spectral domain-optical coherence tomography (SD-OCT) system was used to measure the ganglion cell-inner plexiform layer (GC-IPL) and retinal nerve fiber layer (RNFL) thicknesses. To assess the cognitive performance of all participants, detailed neurological examinations, including the mini-mental state examination (MMSE), were performed by the same neurologist. RESULTS: There were no significant differences among the groups in terms of age (p =0.348) or gender (p =0.935). The mean RNFL thicknesses were significantly different among the groups (85.2 ± 14.7, 76.8 ± 10.3, and 91.4 ± 7.7 µm in the POAG, NTG, and C subjects, respectively; p <0.001). The mean GC-IPL thicknesses were 77.5 ± 9.7 µm in the POAG group, 73.4 ± 7.8 µm in the NTG group, and 78.8 ± 3.8 µm in the C group. Differences among the groups were not statistically significant (p =0.085). MMSE scores were 26.1 ± 1.4, 25.7 ± 2.3, and 28.8 ± 0.9 in the POAG, NTG, and C groups, respectively. There were significant differences among the three groups (p <0.001). Specifically, there were significant differences between the NTG and C groups (p <0.001), and between the POAG and C groups (p =0.001). There was no significant difference between the POAG and NTG groups (p =0.595). CONCLUSIONS: There appear to be similar risk factors in glaucoma and neurodegenerative disorders that cause deterioration in cognitive performance. Comparing the low MMSE scores of the POAG and NTG patients with the scores of healthy C participants supports our hypothesis. Consequently, it is recommended that a neurologist should also examine glaucoma patients.