Ersan Çelik

Influence of abutment material and luting cements color on the final color of all ceramics

Abstract Purpose. The purpose of this study is to evaluate the effects of different abutment materials and luting cements color on the final color of implant-supported all-ceramic restorations. Materials and methods. Ten A2 shade IPS e.max Press disc shape all-ceramic specimens were prepared (11 × 1.5 mm). Three different shades (translucent, universal and white opaque) of disc shape luting cement specimens were prepared (11 × 0.2 mm). Three different (zirconium, gold-palladium and titanium) implant abutments and one composite resin disc shape background specimen were prepared at 11 mm diameter and appropriate thicknesses. All ceramic specimens colors were measured with each background and luting cement samples on a teflon mold. A digital spectrophotometer used for measurements and data recorded as CIE L*a*b* color co-ordinates. An optical fluid applied on to the samples to provide a good optical connection and measurements on the composite resin background was saved as the control group. ΔE values were calculated from the ΔL, Δa and Δb values between control and test groups and data were analyzed with one-way variance analysis (ANOVA) and mean values were compared by the Tukey HSD test (α = 0.05). Results. One-way ANOVA of ΔL, Δa, Δb and ΔE values of control and test groups revealed significant differences for backgrounds and seldom for cement color groups (p the 0.05). Only zirconium implant abutment groups and gold palladium abutment with universal shade cement group were found to be clinically acceptable (ΔE ≤ 3.0). Conclusion. Using titanium or gold-palladium abutments for implant supported all ceramics will be esthetically questionable and white opaque cement will be helpful to mask the dark color of titanium abutment.

Influence of the color of composite resin foundation and luting cement on the final color of lithium disilicate ceramic systems

Statement of problem. Lithium disilicate restorations are commonly used, particularly in the anterior region. The color of the underlying composite resin foundation (CRF) and luting cement may negatively affect the color of lithium disilicate ceramic restorations. Purpose. The purpose of this in vitro study was to investigate the effect of CRF and resin cement materials on the color of lithium disilicate ceramics in 2 different translucencies. Material and methods. Twenty disks (11×1.5 mm, shade A2) were fabricated from medium‐opacity (mo) (n=10) and high‐translucency (ht) (n=10) lithium disilicate (Lds) blocks (IPS e.max Press). Five CRF disks (11×3 mm) were fabricated in 5 different shades (A1, A2, A3, B2, C2) and 30 resin cement disks (11×0.2 mm) in the shades of translucent (Tr), universal (Un=A2), and white‐opaque (Wo). Ceramic specimens were placed on each CRF, and the resin cement combination and color was measured with a spectrophotometer. CIELAB color coordinates were recorded, and the color coordinates of both ceramics on the shades of the A2 CRF and resin cement were saved as the control. Color differences (&Dgr;E00) between the control and test groups were calculated. Data were analyzed with 3‐way analysis ANOVA and compared with the Tukey HSD test (&agr;=.05). Results. The &Dgr;E00 values were influenced by the shades of the CRF, resin cement materials, and also their interactions (P<.05). The &Dgr;E00 values were not affected by the ceramic type. The &Dgr;E00 values of the Wo cement groups (1.73 to 2.96) were significantly higher than those of the other cement shades (0.88 to 1.29) for each ceramic type and CRF shade (P<.05). Conclusions. Lithium disilicate ceramics in 2 different translucencies were similarly influenced by the color of the underlying cement and CRF. When translucent and universal cement shades were used, the core shade did not affect the final color of the ceramics. White opaque cement caused clinically unacceptable color changes in both ceramics on all shades of CRFs except the C2 CRF and when high translucency ceramic was used on the A2 CRF. These changes were clinically acceptable, but perceptible.

Shear Bond Strength of Nanohybrid Composite to the Resin Matrix Ceramics After Different Surface Treatments

OBJECTIVE The purpose of this study was to evaluate the effects of different surface treatments on the shear bond strength (SBS) of a composite resin to the various resin matrix ceramics (RMC). BACKGROUND Clinical applications of physical and chemical surface conditioning methods may be required for RMC to optimize the adhesion of additional resin materials. MATERIALS AND METHODS Ninety-nine RMC specimens (6 × 6 × 2 mm) were prepared from a resin nanoceramic (RNC), a polymer-infiltrated hybrid ceramic (PIHC), and a flexible hybrid ceramic (FHC) block with a cutting machine under copious water. All specimens divided randomly into three surface treatment subgroups (n = 11): (1) untreated (Cnt), (2) tribochemical silica coated (Tbc), and (3) neodymium-doped yttrium aluminum garnet (Nd:YAG) laser irradiated with 3 W (150 mJ/pulse, 20 Hz) for 20 sec. A nanohybrid composite resin was layered with a disc-shape mold (2 × 3 mm) onto the ceramics and submitted to thermal cycling (3000 cycles, 5-55°C). The SBS test of specimens was performed using a universal testing machine. Data were statistically analyzed with two-way analysis of variance (ANOVA) and Tukey HSD test (α = 0.05). RESULTS The type of RMC, surface treatments, and their interactions was statistically significant on SBS, according to the ANOVA (p < 0.05). Both the Tbc and Lsr surface treatments significantly increased the SBS values of FHC (p < 0.001), while significant increases were observed only for Lsr0applied RNC and Tbc applied PIHC groups (p < 0.001). CONCLUSIONS The tribochemical silica coating and laser irradiation techniques may be suitable for improving the surface topography of specific types of RMC. While the same surface treatment technique may not provide similar successful results for all types of RMC, it is recommended to choose the most effective and reliable technique for clinical application.

Experimental evaluation of stress distribution with narrow diameter implants: A finite element analysis

Statement of problem. Narrow diameter implants were developed to allow placement in narrow alveolar ridges. Clinicians may have concerns about the durability and function of such implants. Purpose. The purpose of this finite element study was to compare the stress values occurring on the implant and at the implant bone interface after the application of the static and dynamic forces on narrow diameter, titanium and titanium‐zirconia implants in the maxillary and mandibular second premolar region. Material and methods. Titanium (Ti) and titanium‐zirconium (Ti‐Zr) narrow diameter implants (3.3 mm in diameter, 10 mm in length) were simulated in the maxillary and mandibular second premolar region, and metal‐ceramic crown restorations were designed. Forces of 100 N were applied to crowns in a vertical and oblique (45‐degree angle to the long axis) direction. Maximum and minimum principal stresses in the cortical and trabecular bone and the von Mises stresses and fatigue strength of the implants were evaluated with 3‐dimensional finite element analysis. Results. In vertical and oblique static loading, Ti and Ti‐Zr implants showed similar stress distribution within the same jaw models. However, the von Mises stresses in Ti‐Zr implants were slightly higher than for Ti implants in all models. In oblique static and dynamic loading, all stresses were found higher than vertical loading, and fatigue failure results were found to be more critical than vertical forces. Conclusions. Based on a numerical simulation, Ti and Ti‐Zr alloys can be used successfully as narrow diameter implants in the second premolar area.

Evaluation of the skeletal and dental effects in orthodontic patients with maxillary lateral incisor agenesis

OBJECTIVE The purpose of this study was to evaluate the transverse dimension of the dentoalveolar and skeletal widths in both unilateral (UMLIA) and bilateral (BMLIA) maxillary lateral incisor agenesis groups. MATERIALS AND METHODS The study sample consisted of 59 patients (34 females and 25 males) divided into three groups as UMLIA group (16 patients; 14.94 ± 1.37 years), BMLIA group (21 patients; 14.46 ± 1.53 years) and control group (22 patients; 15.28 ± 1.70 years) without tooth agenesis. Transversal measurements (maxillary and mandibular intercanine, interpremolar, intermolar, intercanine alveolar, interpremolar alveolar, intermolar alveolar widths) were done on dental casts. Craniofacial skeletal measurements were done with posteroanterior cephalometric radiographs. Statistical testing was performed with the one-way variance analysis, Kruskal-Wallis and post hoc tests. RESULTS UMLIA and BMLIA groups had statistically significantly narrower skeletal apical base of the maxilla, maxillary intercanine and intercanine alveolar widths compared with the control group (P < .05). Moreover, UMLIA and BMLIA groups had statistically significantly similar dental, alveolar and skeletal features (P > .05). CONCLUSIONS The UMLIA and BMLIA groups showed statistically significantly smaller values for maxillary intercanine, maxillary intercanine alveolar and skeletal maxillary widths compared with the control group. CLINICAL SIGNIFICANCE This study provides information the transverse dimension of the dental, alveolar and skeletal widths with maxillary lateral incisor agenesis patients. Knowledge of transverse dimension of the dental, alveolar and skeletal widths with maxillary lateral incisor agenesis patients is important for diagnosis and treatment planning.

Amelogenezis imperfekta hastasının oral rehabilitasyonu: Olgu sunumu

Amelogenezis imperfekta hastasinin oral rehabilitasyonu: Olgu sunumu Amelogenezis imperfekta (AI) sut ve daimi dentisyonu etkileyen herediter bir mine gelisim anomalisidir. Dislerde mine hipoplazisi, hipomaturasyonu veya hipokalsifikasyonu ile karakterize olan bu anomalinin tedavisinde estetik ve fonksiyonun kazandirilmasi ile birlikte psikolojik olarak da olumlu sonuclarla hasta memnuniyetinin saglanmasi amaclanmaktadir. Bu olgu raporunda; klinigimize basvuran hipomature tip AI’li genc erkek hastanin oral rehabilitasyonu sunulmaktadir.