Sedanur Turgut

Colour stability of laminate veneers: An in vitro study

OBJECTIVES Obtaining a perfect aesthetic, especially with the translucent porcelain laminate veneers; shade of the porcelain, type of the resin cement and their long term colour stability are important factors to achieve aesthetic success. The purpose of the study was to assess the effect of different resin cement systems and UV ageing on the colour of full ceramic laminates with different shades. METHODS 392 discs were made with A1, A3, HO and HT shades of IPS e.max Press with 0.5mm thickness. Different shades of light cured Variolink Veneer, Ivoclar Vivadent (+3, MO, -3); Rely X Veneer, 3M ESPE (A1, A3, White Opaque, Translucent); and dual cured Maxcem Elite, Kerr (White, Yellow, White Opaque, Clear); and Variolink II, Ivoclar Vivadent (White Opaque, Translucent) resin cements were applied on the porcelain discs with a thickness of 0.1mm. Colour differences of the porcelain substructures after cementation and 300 h (150 kJ/m(2)) of UV ageing test, were examined with a colorimeter (Shade Eye Ex, Shofu, Japan). The results were analysed statistically with Wilcoxon signed-rank and Kruskal-Wallis test. The mean values of L*, a*, and b* were also compared using Paired Sample t-test. Spearmans Rank Correlation test was used to analyse the correlation between ceramics with resin-cemented ceramics after ageing. The data analyses were evaluated at a significance level of p < 0.05 for all individual tests without any adjustment. RESULTS UV ageing caused significant colour change on ceramics and also cemented ceramics (p < 0.05). Whilst L* and a* values decreased, b* values increased after ageing. Discoloration was between 0.8-1.2 ΔE for ceramic discs and 1.4-3.1 ΔE for cemented ceramics. There is no significant difference on the colour change of dual or light cured resin cements, which were polymerized beneath the porcelain substructure with 0.5mm thickness. Although statistically significant differences were observed for all specimens, the magnitudes of the mean colour differences were at an acceptable perception level and were considered clinically acceptable (ΔE<3.5). CONCLUSIONS Resin cements and ageing process influence the colour of porcelain laminate veneers. Cementation of laminates with either dual or light-cure resin cements does not effect the long term colour stability differently.

Gender Difference in Prevalence of Signs and Symptoms of Temporomandibular Joint Disorders: A Retrospective Study on 243 Consecutive Patients

Background: This study evaluated the prevalence of the signs and symptoms of temporomandibular joint disorder (TMD) among patients with TMD symptoms. Methods: Between September 2011 and December 2011, 243 consecutive patients (171 females, 72 males, mean age 41 years) who were referred to the Department of Prosthodontics, Faculty of Dentistry, Karadeniz Technical University, Trabzon were examined physically and completed a questionnaire regarding age, gender, social status, general health, antidepressant drug usage, dental status, limited mouth opening, temporomandibular joint (TMJ) sounds, and parafunctions (bruxism, clenching). The data were analyzed using the chi-square test and binary logistic regression model (alpha = 0.05). Results: With a frequency of 92%, pain in the temporal muscle was the most common symptom, followed by pain during mouth opening (89%) in both genders. TMJ pain at rest, pain in the masseter muscle, clicking, grinding, and anti-depressant use were significantly more frequent in females than males. Age (p=0.006; odds ratio 0.954; 95% CI 0.922-0.987) and missing teeth (p=0.003; odds ratio 3.753; 95% CI 1.589-8.863) had significant effects on the prevalence of TMD. Conclusion: Females had TMD signs and symptoms more frequently than males in the study population. The most common problem in both genders was pain.

Effect of resin cement and ceramic thickness on final color of laminate veneers: an in vitro study.

STATEMENT OF PROBLEM Different shades of resin cements may adversely affect the final color of translucent restorations, especially thin laminates. PURPOSE The purpose of this study was to determine the effect of different types and shades of resin cement and different thicknesses and shades of IPS Empress Esthetic ceramics on the final color of laminate restorations. MATERIAL AND METHODS A total of 392 disks were made with A1, A3, EO, and ET shades of IPS Empress Esthetic with 0.5-mm and 1-mm thicknesses. Two dual-polymerizable and 2 light-polymerizable resin cement systems from different manufacturers (a total of 13 shades) were selected for cementation (n=7). Similarly, with porcelain ingot shades A1 and A3, opaque and translucent shades were selected from the Rely X Veneer and Maxcem Elite cement systems. For the opaque and translucent shades of the Variolink II resin cement system, the highest and lowest (+3 and -3) and medium (0) shades of Variolink Veneer cement were included in the study. Color changes in the porcelain substructures after cementation were examined with a colorimeter, and color differences (ΔE) were calculated. The results were analyzed with Wilcoxon signed-ranks and Kruskal-Wallis tests (α=.05). RESULTS The results indicated that the color of porcelain disks changed significantly after cementation (P<.001). Most of the color changes appeared after cementation with Variolink-3 Veneer in all porcelain shades. The smallest color change was obtained from Variolink II Tr in the EO shade of porcelain. The colors of the same shades of different resin cement systems were found at different coordinates in the CIE L*a*b* system. The final color difference (ΔE) of cemented veneers decreased when ceramic thickness increased. CONCLUSIONS The type and shade of resin cement and the thickness and shade of the ceramic all influenced the resulting optical color of laminate restorations.

Optical properties of current ceramics systems for laminate veneers

OBJECTIVES Full-ceramic systems can be produced by different techniques (layering, heatpressing, CAD/CAM) and have various compositions with different crystalline contents that may affect the optical properties of laminate restorations. METHODS A total of 60 specimens were prepared from e.max Press, e.max CAD, Empress Esthetic, e.max Ceram, Inline, and ZirPress systems (A1 shade; diameter 10mm; thickness 0.5 ± 0.05mm). The L*, a*, and b* values, chroma and translucency (TP) of each system were recorded before and after ageing. The statistical analyses were performed by ANOVA, Tukeys tests and the paired sample t-test (p<0.05). RESULTS The L* value of the shade guide was significantly different from those of the full-ceramic systems; however, there were no significant differences between the a* values of Ceram, Esthetic, Inline and Zirpress. There were significant differences between the b* values of the shade guide compared with the full-ceramics except for e.max Press. The L* values decreased, and the a* and b* values increased after the ageing process for all groups. There were no significant differences between the ΔE values of the ceramic systems (p>0.05). The TP values decreased, and the chroma value increased significantly after the ageing process (p>0.05). The chroma of the shade guide was found to be the highest. CONCLUSIONS None of the full-ceramic systems was able to match the color of the shade guide. The chemical structures of the ceramic systems were more effective for determining the optical parameters than the fabrication techniques. Ageing caused full-ceramics to become more opaque, darker, reddish and yellowish.

Discoloration of provisional restorations after oral rinses.

Purpose: Oral rinses are widely used to promote periodontal health with provisional restorations during the interim period. The aim of this study was to compare the discoloration of provisional restoration materials with different oral rinses. Material and Methods: A total of 140 disc-shaped specimens (shade A2) (10 mm x 2 mm) were prepared from one PMMA-based (TemDent Classic®) and three different bis-acrylic-based (Protemp II®, Luxatemp® and Fill-In®) provisional restoration materials (n=7). The color values (L*, a*, and b*) of each specimen were measured before and after exposure with a colorimeter, and the color changes (∆E) were calculated according to the CIE L*a*b* system. The specimens were immersed in each of the 4 oral rinses (alcohol-containing mouthwash, chlorhexidine, benzydamine HCl, benzydamine HCl and chlorhexidine) twice a day for 2 minutes. After 2 minutes of immersion in the oral rinses, the specimens were immersed in artificial saliva. The specimens were exposed to the oral rinses and the artificial saliva for 3 weeks. Two-way ANOVA, the Bonferroni test and the paired sample t-test were used for statistical analyses (p<0.05). Results: Comparison of the discoloration from the oral rinses after immersion for three weeks revealed no significant differences (p>0.05). The lowest color change was observed in PMMA-based Temdent in all oral rinses (p<0.05). There were no significant differences between the bis-acryl composites after immersion in saliva or the mixture of benzydamine HCl and chlorhexidine and the alcohol-containing mouthwash for 3 weeks (p>0.05). After immersion in chlorhexidine, the color change values of Protemp II and Fill-in showed significant differences (p=0.018). Protemp II also showed less discoloration than the other bis-acryl composites, and this color change was statistically significant (p <0.05). For all oral rinses, the L* value decreased while b* values increased, and this color change was found to be statistically significant (p <0.05). A* values were found to be significantly higher with oral rinses (p<0.05), except Protemp II immersed in benzydamine HCl or alcohol-containing mouthwash. Conclusions: The type of the oral rinse did not affect the discoloration process. For long-term esthetic results, choosing MMA-based materials for provisional restorations appears to be more effective.

Achieving the desired colour in discoloured teeth, using leucite-based cad-cam laminate Systems

OBJECTIVES To evaluate the cumulative effect of the abutment tooth and resin cement colour on the resultant optical properties of porcelain laminate veneers (PLVs) fabricated with leucite-based CAD/CAM blocks with different shades and thicknesses. METHODS A total of 224 ceramic specimens were prepared from the IPS Empress CAD with four different shades of HT-A1, LT-A1, MT-A1 and Bl-1. Resin composite discs were prepared with shade A3.5. For the cementation, 4 different shades of light-cure resin cements were chosen. L*, a*, and b* values, as well as the chroma (C) and hue (h) values of each cemented ceramic and the A1 shade table, were recorded. RESULTS L*, Cab* and hab* values of the cemented ceramics were influenced by ceramic shade, ceramic thickness, cement shade, and interaction terms of the three variables. There were significant differences between the 1-mm-thick ceramic veneers that exhibited higher L* and lower Cab* values compared with veneers that were 0.5mm in thickness. Using the Tr shade cement resulted in lower L* and higher Cab* values for all thicknesses and ceramic shades, whereas the WO shade cement resulted in higher values. CONCLUSIONS The selected colour of a laminate restoration is significantly affected by the ceramic shade, ceramic thickness and resin cement shade. Using the WO shade resin cement seems to be more effective in masking the discoloured abutment tooth. Clinicians should also select the translucency level of the ceramic block with the shade when a leucite-based CAD/CAM system is chosen to treat a discoloured tooth.

How will surface treatments affect the translucency of porcelain laminate veneers

PURPOSE The purpose of this study was to evaluate whether surface treatments affect the translucency of laminate veneers with different shades and thicknesses. MATERIALS AND METHODS A total of 224 disc-shaped ceramic veneers were prepared from A1, A3, HT (High Translucent) and HO (High Opaque) shades of IPS e.max Press (Ivoclar Vivadent) with 0.5 mm and 1.0 mm thicknesses. The ceramics were divided into four groups for surface treatments. Group C: no surface treatments; Group HF: etched with hydrofluoric acid; Group SB: sandblasted with 50-µm Al2O3; and Group L; irradiated with an Er;YAG laser. A translucent shade of resin cement (Rely X Veneer, 3M ESPE) was chosen for cementation. The color values of the veneers were measured with a colorimeter and translucency parameter (TP) values were calculated. A three-way ANOVA with interactions for TP values was performed and Bonferroni tests were used when appropriate (α=0.05). RESULTS There were significant interactions between the surface treatments, ceramic shades and thicknesses (P=.001). For the 0.5-mm-thick specimens there were significant differences after the SB and L treatments. There was no significant difference between the HF and C treatments for any shades or thicknesses (P>.05). For the 1-mm-thick ceramics, there was only a significant difference between the L and C treatments for the HT shade ceramics (P=.01). There were also significant differences between the SB and C treatments except not for the HO shades (P=.768). CONCLUSION The SB and L treatments caused laminate veneers to become more opaque; however, HF treatment did not affect the TP values. When the laminate veneers were thinner, both the shade of the ceramic and the SB and laser treatments had a greater effect on the TP values.

Do surface treatments affect the optical properties of ceramic veneers

STATEMENT OF PROBLEM Surface treatments may affect the optical properties of ceramic veneers before cementation. PURPOSE The purpose of this study was to evaluate whether various surface treatments affect the optical properties of different types of ceramic veneers. MATERIAL AND METHODS Disk-shaped ceramic veneers (N=280) were prepared from the IPS e.max Press, e.max CAD, Empress Esthetic, e.max Ceram, and Inline ceramic systems with 0.5-mm and 1.0-mm thicknesses. The ceramics were divided into 4 groups: no surface treatments; etched with hydrofluoric acid; airborne-particle abraded with 30-μm Al2O3; and irradiated with erbium:yttrium-aluminum-garnet laser. A translucent shade of resin was chosen for cementation. Color parameters were examined with a colorimeter. Statistical analyses were done with 3-way ANOVA and the Bonferroni test (P=.05). RESULTS Significant interactions were noted between the surface treatments, ceramic type, and thickness for ΔE values (P=.01), and no significant interactions were noted for L* (P=.773), a* (P=.984), and b* (P=.998). The greatest color change occurred after airborne-particle abrasion with 0.5-mm-thick e.max Press (2.9 ΔE). Significant differences in ΔE values were found among the hydrofluoric acid, airborne-particle abrasion, and laser groups for 0.5-mm-thick ceramics, except IPS Inline, and among the hydrofluoric acid, airborne-particle abrasion, and laser groups for 1.0-mm-thick ceramics, except Empress Esthetic ceramics. CONCLUSIONS The color change of the ceramics increased after the surface treatments, particularly as the ceramics became thinner.

Peel strength of denture liner to PMMA and polyamide: laser versus air-abrasion

PURPOSE This study investigated the effect of laser parameters and air-abrasion on the peel strength of silicon-based soft denture liner to different denture resins. MATERIALS AND METHODS Specimens (N=180) were prepared out of three different denture base resins (Rodex, cross-linked denture base acrylic resin; Paladent, heat-cured acrylic resin; Deflex, Polyamide resin) (75 mm × 25 mm × 3 mm). A silicon-based soft denture liner (Molloplast B) was applied to the denture resins after the following conditioning methods: a) Air-abrasion (50 µm), b) Er,Cr:YSGG laser (Waterlase MD Turbo, Biolase Technology) at 2 W-20 Hz, c) Er,Cr:YSGG laser at 2 W-30 Hz, d) Er,Cr:YSGG laser at 3 W-20 Hz, e) Er,Cr:YSGG laser at 3 W-30 Hz. Non-conditioned group acted as the control group. Peel test was performed in a universal testing machine. Failure modes were evaluated visually. Data were analyzed using two-way ANOVA and Tukeys test (α=.05). RESULTS Denture liner tested showed increased peel strength after laser treatment with different parameters (3.9±0.4 - 5.58±0.6 MPa) compared to the control (3.64±0.5 - 4.58±0.5 MPa) and air-abraded groups (3.1±0.6 - 4.46±0.3 MPa), but the results were not statistically significant except for Paladent, with the pretreatment of Er,Cr:YSGG laser at 3 W-20 Hz. Polyamide resin after air-abrasion showed significantly lower peel strength than those of other groups (3.1±0.6 MPa). CONCLUSION Heat-cured acrylic resin, PMMA, may benefit from Er,Cr:YSGG laser treatment at 3 W-20 Hz irradiation. Air-abrasion of polyamide resins should be avoided not to impair their peel bond strengths to silicon-based soft denture liners.

Effects of Protective Resin Coating on the Surface Roughness and Color Stability of Resin-Based Restorative Materials

The aim of this study was to evaluate the effects of nanofilled protective resin coating (RC) on the surface roughness (Ra) and color stability (ΔE) of resin-based restorative materials (RM) (compomer (C), nanofilled composite (NF), and microhybrid composite (MH)) after being submitted to the ultraviolet aging (UV) method. Thirty-six specimens were prepared (n = 6 for each group). The Ra and (ΔE) values and SEM images were obtained before and after UV. Significant interactions were found among the RM-RC-UV procedures for Ra (P < 0.001). After the specimens were submitted to UV, the Ra values were significantly increased, regardless of the RC procedure (with RC; P < 0.01 for all, without RC; C (P < 0.01), NF (P < 0.001), and MH (P < 0.001)) for each RM. Significant interactions were found between the RM-RC (P < 0.001) procedures for the ΔE values. The ΔE values were increased in each group after applying the RC procedures (P < 0.001). Protective RC usage for RM could result in material-related differences in Ra and ΔE as with used UV method.