Objective: The aim of this study was to evaluate the effect of different surface treatments: sandblasting, liners, and different laser irradiations on shear bond strength (SBS) of pre-sintered zirconia to veneer ceramic. Background data: The SBS between veneering porcelain and zirconium oxide (ZrO 2 ) substructure was weak. Various surface treatment methods have been suggested for zirconia to obtain high bond strength to veneering porcelain. There is no study that evaluated the bond strength between veneering porcelain and the different surface treatments on pre-sintered ZrO 2 substructure. Methods: Two hundred specimens with 7 mm diameter and 3 mm height presintered zirconia blocks were fabricated. Specimens were randomly divided into 10 groups (n = 20) according to surface treatments applied. Group C, untreated (Control); Group E, erbium:yttrium-aluminum-garnet (Er:YAG) laser irradiated; Group N, neodymium:yttrium-aluminum-garnet (Nd:YAG) laser irradiated; Group SB, sandblasted; Group L, liner applied; Group NL, Nd:YAG laser irradiated + liner applied; Group EL, Er:YAG laser irradiated + liner applied; Group SN, sandblasted + Nd:YAG laser irradiated; Group SE, sandblasted + Er:YAG laser irradiated; and Group SL, sandblasted + liner applied. The disks were then veneered with veneering porcelain. Before the experiment, specimens were steeped in 37°C distilled water for 24 h. All specimens were thermocycled for 5000 cycles between 5°C and 55°C with a 30 sec dwell time. Shear bond strength test was performed at a crosshead speed of 1 mm/min. The fractured specimens were examined under a stereomicroscope to evaluate the fracture pattern. Results: Surface treatments significantly changing the topography of the yttrium-stabilized tetragonal zirconia (Y-TZP) ceramic according to scanning electron microscopic (SEM) images. The highest mean bond strength value was obtained in Group SE, and the lowest bond strength value was observed in NL group.Bond strength values of the other groups were similar to each other. Conclusions: This study shows that sandblasting + Er:YAG, sandblasting, Er:YAG + liner, sandblasting + Nd:YAG, and Er:YAG laser treatment on pre-sintered ZrO 2 substructure increased the bond strength to veneering porcelain, compared with other surface treatments. After different surface treatments, there was no difference in surface roughness of pre-sintered zirconia to compare after sintering; sintering enhanced the bond strength within the limitations of present study.

This study evaluated the effect of various surface treatments on the tensile bond strength of a silicone-based soft denture liner to two chemically different denture base resins, heat-cured polymethyl methacrylate (PMMA), and light-activated urethane dimethacrylate or Eclipse denture base resin. PMMA test specimens were fabricated and relined with a silicone-based soft denture liner (group AC). Eclipse test specimens were prepared according to the manufacturer's recommendation. Before they were relined with a silicone-based soft denture liner, each received one of three surface treatments: untreated (control, group EC), Eclipse bonding agent applied (group EB), and laser-irradiated (group EL). Tensile bond strength tests (crosshead speed = 5 mm/min) were performed for all specimens, and the results were analyzed using the analysis of variance followed by Tukey's test (p = 0.05). Eclipse denture base and PMMA resins presented similar bond strengths to the silicone-based soft denture liner. The highest mean force was observed in group EL specimens, and the tensile bond strengths in group EL were significantly different (p < 0.05) from those in the other groups.

Nd:YAG laser irradiation alone was not effective in altering the zirconia surface morphology.

No abstract

Treatment of a patient with amelogenesis imperfecta (AI) presents a real problem from both functional and esthetic points of view. An esthetic result also will result in an improvement in the patient's quality of life. This clinical report illustrates the oral rehabilitation of a 24-year-old man diagnosed with hypomature type of AI. The aim of treatment was to both restore esthetics and improve masticatory function. Esthetic expectations of the patient were successfully attained by placing all-porcelain crowns from canine to canine in each arch, 12 crowns total. Moreover, metal-ceramic three-unit fixed partial dentures for the missing mandibular right first molars were fabricated for the patient's masticatory function. Resin composite restorations were applied to the maxillary premolars, the maxillary right first molar, the mandibular left premolars, and the right first premolar to modify the occlusion. No deterioration in the restorations and no pathology associated with the rehabilitation were found at the 1-year recall, and the patient's esthetic and functional expectations were satisfied. CLINICAL SIGNIFICANCE This article provides an overview of an interdisciplinary approach to treating the difficult condition of AI using a combination of treatments to achieve optimal esthetics and function.

Lasing of the ridge lap area to enhance the bond strength of acrylic resin denture teeth to PMMA denture base resin might be an alternative to wetting with MMA monomer. To overcome tooth debonding, surface treatment of the ridge lap area should be performed as part of denture fabrication.

The effects of the chemical nature of TCMs on the SBS values appeared to be clinically negligible, whereas the type of surface treatments had a significant influence on bond strengths. Er:YAG laser irradiation caused a significant increase in bond strength between the TCMs and orthodontic brackets.

All the chemical disinfectants used in the study affected the color values of ADTs. Furthermore, ΔE* values increased along with the number of immersion cycles and total immersion time.