Microtensile bond strengths of adhesively bonded polymer-based CAD/CAM materials to dentin.

This in vitro study aimed to evaluate the effect of two different polymer-based CAD/CAM materials; resin-nano ceramic (Lava Ultimate [LVU]) and composite (CERASMART [CS]), their different surface pre-treatments, and use of different resin cements on the µTBS of adhesively bonded CAD/CAM onlays to dentin. CAD/CAM materials were cut into slabs and divided into five groups according to the surface pre-treatments applied: Silane Primer, OptiBond XTR adhesive, Silane Primer+OptiBond XTR adhesive, Single Bond Universal (SBU), and RelyX Ceramic Primer+SBU. The LVU and CS specimens were bonded to the mid-coronal dentin of 50 non-carious human molars using NX3 resin cement with OptiBond XTR or RelyX Ultimate with SBU. µTBS was evaluated after 5,000 thermocycling and analysed with three-way-ANOVA and post-hoc Tukey's tests (p<0.05). The µTBS was significantly influenced by the type of CAD/CAM material (p<0.0001) surface pre-treatments (p<0.05) and resin cements (p<0.05). Regardless of the pre-treatments and resin cements, bonding of the composite CAD/CAM material to dentin was higher than the resin nano-ceramic material.

The Effect of Luting Cement and Titanium Base on the Final Color of Zirconium Oxide Core Material.

PURPOSE: To evaluate the effects of different types of luting cements and different colors of zirconium cores on the final color of the restoration that simulates implant-supported fixed partial dentures (FPDs) by using a titanium base on the bottom. MATERIALS AND METHODS: One hundred and twenty zirconium oxide core plates (Zr-Zahn; 10 mm in width, 5 mm in length, 0.5 mm in height) were prepared in different shades (n = 20; noncolored, A2, A3, B1, C2, D2). The specimens were subdivided into two subgroups for the two types of luting cements (n = 10). The initial color measurements were made on zirconium oxide core plates using a spectrometer. To create the cement thicknesses, stretch strips with holes in the middle (5 mm in diameter, 70 µm in height) were used. The second measurement was done on the zirconium oxide core plates after the application of the resin cement (U-200, A2 Shade) or polycarboxylate cement (Lumicon). The final measurement was done after placing the titanium discs (5 mm in diameter, 3 mm in height) in the bottom. The data were analyzed with two-way ANOVA and Tukey's honestly significant differences (HSD) tests (α = 0.05). RESULTS: The ∆E*ab value was higher in the resin cement-applied group than in the polycarboxylate cement-applied group (p < 0.001). The highest ∆E*ab value was recorded for the zirconium oxide core-resin cement-titanium base, and the lowest was recorded for the polycarboxylate cement-zirconium oxide core (p < 0.001). CONCLUSION: The luting cement, the presence of titanium, and the color of zirconium are all important factors that determine the final shade of zirconia cores in implant-supported FPDs.

Comparison of the marginal fit of different coping materials and designs produced by computer aided manufacturing systems.

In this study, marginal adaptations of different copings fabricated with CAD/CAM or MAD/CAM were analysed. Celay and Zirkonzahn groups were fabricated by MAD/CAM, LAVA and DC-Zircon groups were fabricated by CAD/CAM. Casting metal copings were used as the control group. An implant abutment that was embedded in octagonal acrylic block was used to prepare the copings. Sixteen previously established points were marked and the measurements were performed with the stereomicroscope (at × 150). The marginal fit of the samples were evaluated by calculating the mean measurements of each 16 points. The statistical analysis was performed by Tukey multiple comparisons test at 95% confidence interval. The groups can be summarized as follows in terms of marginal gap, from the lowest to highest: LAVA (24.6 ± 14.0 µm)

Effect of Er:YAG laser irradiations on shear bond strength of three self-adhesive resin cements to dentin.

OBJECTIVE: The purpose of this study was to evaluate the influence of Er:YAG laser irradiation on shear-bond strength of self-adhesive resin cements to dentin. BACKGROUND DATA: Different laser-irradiation settings are used for dentin-surface pretreatment, which may affect the bond strength of resins. METHODS: Fourty-five extracted third molars were selected, sectioned in a mesiodistal direction, and 90 tooth slabs were obtained. The teeth were ground to expose the dentinal hard tissue with 320- and 600-grit silicon carbide disks. The specimens were randomly assigned to nine groups (n = 10). Surfaces for each group were laser irradiated with 30 Hz/70 mJ (2.1 W), 30 Hz/160 mJ (4.8 W), or non-irradiated (control) for each resin cement (SmartCem2, RelyX Unicem, Multilink Automix). All specimens were stored in distilled water at 37°C for 24 h after luting. Shear-bond testing was carried out by using a Universal testing machine with a crosshead speed of 0.5 mm/min. Data were analyzed with one-way ANOVA and post hoc Tukey HSD tests (p < 0.05). RESULTS: The highest bond-strength value was obtained with SmartCem2, which was irradiated with Er:YAG laser (30 Hz/160 mJ). The lowest values were exhibited in the control group of SmartCem2, RelyX Unicem and Multilink Automix, respectively (4.92 ± 1.68, 7.17 ± 2.88, and 7.93 ± 3.05). CONCLUSION: The 2.1-W and 4.8-W laser ablation did not show any statistically difference for RelyX Unicem and Multilink Automix materials. However, in the SmartCem2 group, laser irradiated with 30 Hz/160 mJ application increased the bond-strength values, and the highest bond-strength results were obtained in this group.

Evaluating factors that affect the shade-matching ability of dentists, dental staff members and laypeople.

BACKGROUND: The authors conducted a study to evaluate the influence of dentists' and nondentists' experience, age, sex, eye color and use of eyeglasses or contact lenses on tooth shade-matching ability. METHODS: The authors included 120 participants in this study conducted in Istanbul (periodontists, oral and maxillofacial surgeons, orthodontists, endodontists, pediatric dentists, prosthodontists, restorative dentists, general dentists in private practice, dental technicians, dental assistants, dental assistant students and laypeople). The authors assigned participants to one of three groups: group 1 was composed of prosthodontists, restorative dentists and dental technicians; group 2 consisted of other dental specialists and general dentists; and group 3 included dental assistants, dental assistant students and laypeople. The authors asked participants to match the shades of three artificial maxillary right central incisors (Vitapan acrylic teeth [shades 2L1.5, 1M2, 2R1.5], Vita Zahnfabrik, Bad Säckingen, Germany) by using a shade guide system (Vita Toothguide 3D-Master, Vita Zahnfabrik). They calculated shade matching for the three color components (value, hue, chroma) and analyzed the results by using a chi(2) test. RESULTS: The rate of success in matching the shade for IM2 was 53.3 percent for participants in group 1, 30 percent for participants in group 2 and 20 percent for participants in group 3 (P = .017). However, there were no significant differences between the three groups for shades 2L1.5 and 2R1.5. Professional experience (P = .003) and age (P = .027) were associated with shade-matching success for tooth shade 2L1.5 only. The results showed no statistically significant differences with respect to sex, eye color or use of eyeglasses or contact lenses. CONCLUSIONS: Dental care professionals who routinely performed restorative procedures matched the shades better than did participants in other groups. Professional experience was associated positively with the outcome, while sex, eye color and use of eyeglasses or contact lenses did not have any effect on shade-matching results. CLINICAL IMPLICATIONS: To improve shade-matching skills, clinicians should participate in hands-on courses, continuing education classes and other training programs.

Interdisciplinary management of a patient with skeletal anteroposterior discrepancy, impacted canine, and missing teeth.

For patients with complex dentofacial problems, orthodontic treatment is often not enough to obtain optimal esthetic and functional results. This case report demonstrates the treatment of a patient with skeletal anteroposterior discrepancy through an interdisciplinary approach and emphasizes the importance of collaboration with other dental disciplines to achieve the desired esthetic results.

An alternative treatment approach to gingival recession: gingiva-colored partial porcelain veneers: a clinical report.

This clinical report describes the treatment of excessive gingival recession involving maxillary right and left central incisors in a 30-year-old woman. The loss of the gingival soft tissue caused an increase in crown length. Gingiva-colored partial porcelain laminate veneers were applied to imitate the lost gingiva and to provide a natural anatomical tooth length. This method may be a minimally invasive alternative treatment method for gingival soft tissue loss, providing esthetic results and patient satisfaction.

Elongated mandibular coronoid process as a cause of mandibular hypomobility.

There are multiple factors in cases of mandibular hypomobility. One of these factors is elongated coronoid process. Two cases are presented to illustrate elongated coronoid process leading to mandibular hypomobility to help prevent misdiagnosis by clinicians. Coronoid process elongation is a rare condition. Both cases reported here had pulpitis on the teeth, however endodontic treatment could not be performed due to the restricted mouth opening in both cases. There were clinical findings of restricted range of motion, especially during protrusive movements. The restrictive movements did not cause pain for either patient, and the patients were not aware of their restricted mouth opening. Panoromic radiographs were taken and evaluated. The radiographs showed elongated coronoid process bilaterally. Three-dimensional computerized tomography was taken in one case only, due to the patient's financial restrictions. In cases of restricted mandibular opening, elongated coronoid process must be considered when diagnosing the cause.