Effect of surface treatments on wear and surface properties of different CAD-CAM materials and their enamel antagonists.

STATEMENT OF PROBLEM Which surface treatment provides optimal surface roughness, microhardness, and wear behavior for computer-aided design and computer-aided manufacturing (CAD-CAM) materials and their enamel antagonists is unclear. PURPOSE The purpose of this in vitro study was to evaluate the effect of surface treatment on the surface roughness, microhardness, and 2-body wear of different CAD-CAM materials and their enamel antagonists. MATERIAL AND METHODS Monolithic zirconia, polymer-infiltrated ceramic network, lithium disilicate, leucite-reinforced ceramic, zirconia-reinforced lithium silicate, and feldspathic ceramic specimens were sliced into 2-mm-thick rectangular plates and divided into polished or glazed subgroups (n=6). After surface roughness and microhardness measurements, the specimens were loaded at 49 N for 250 000 cycles and simultaneously thermocycled (5 °C and 55 °C). All specimens were scanned before and after the wear test by using a scanner. The volumetric loss and wear depth of the materials and the volumetric and height loss of the enamel were calculated, and scanning electron microscope images of the specimens were made. Multiple 2-way ANOVAs and Tukey honestly significant difference tests were used to assess the effect of material and surface treatment on surface roughness, microhardness, and wear behavior of materials and enamel (α=.05). RESULTS Material and surface treatment interactions affected the surface roughness (P<.001), microhardness (P<.001), volumetric loss of materials (P=.044), and height loss of enamel (P<.001). CONCLUSIONS Polishing resulted in higher surface roughness and microhardness than glazing. Volumetric loss depended on the material, which affected the height loss of the antagonists. Glazing and polishing had similar effects on the volumetric loss of materials and antagonists. No correlation was found between the wear of materials and the antagonists, nor between the surface roughness of materials and the volumetric loss of materials or antagonists

Amelogenesis Imperfecta and Generalized Gingival Overgrowth Resembling Hereditary Gingival Fibromatosis in Siblings: A Case Report

Amelogenesis imperfecta (AI) is a group of hereditary disorders primarily characterized by developmental abnormalities in the quantity and/or quality of enamel. There are some reports suggesting an association between AI and generalized gingival enlargement. This paper describes the clinical findings and oral management of two siblings presenting both AI and hereditary gingival fibromatosis (HGF) like generalized gingival enlargements. The treatment of gingival enlargements by periodontal flap surgery was successful in the management of the physiologic gingival form for both patients in the 3-year follow-up period. Prosthetic treatment was also satisfactory for the older patient both aesthetically and functionally

Effects of Different Glaze Treatments on the Optical Properties and Roughness of Lithium Disilicate Ceramics

Objectives: To investigate effects of different glaze procedures on the colour, translucency, and roughness of lithium disilicate (LDS) ceramics after short-term ageing.Materials and Methods: Eighteen LDS specimens (thickness: 0.6 mm) were divided into three groups (paste (EP), spray (ES), and powder–liquid glaze (EL)) based on the type of glaze treatment (n=6). After glaze firings, specimens were thermally aged (5000 cycles). Before and after thermocycling, the colour, translucency, and roughness values of the specimens were measured. Before and after thermocycling, the translucency and roughness data were analysed using a one-way analysis of variance (ANOVA) and compared using a Wilcoxon signed-rank test. Changes in colour, translucency, and roughness data were analysed using one-way ANOVA, and the correlations between them were analysed using Spearman’s correlation analysis (p=.05).Results: The EL group showed the highest and clinically unacceptable colour change value (p≤.005). Before and after ageing, the EL group exhibited higher translucency than the other groups (p&lt;.001), and the EL and EP groups exhibited higher roughness values than the ES group (p≤.001). Wilcoxon signed-rank test results showed that although a significant difference between the initial and final translucency values was observed in the EL group (p=.028), no significant differences between the initial and final roughness values were observed in each group. Only in the EL group, a significant correlation was found between the colour and translucency change values (r=0.943, p=.005).Conclusions: After short-term ageing, based on the evaluation of the LDS ceramics' colour and translucency changes, ES and EP treatments are preferable for glazing. When dentists select a material (EP, EL, ES) for glazing LDS ceramics, they should consider the effects of this material on the optical properties and surface roughness of LDS ceramics

Effect of Surface Finishing Methods and Aging on Surface Roughness and Optical Properties of Zirconia-Reinforced Lithium Silicate Glass-Ceramic

ABSTRACT Objectives: The effects of three different surface finishing methods and aging on the surface roughness and optical properties of zirconia-reinforced lithium silicate (ZLS) glass-ceramic were investigated. Materials and Methods: Rectangular specimens (0.6 mm thickness) were sliced from ZLS blocks (N=36). Three different types of surface finishing [glazing combined with crystallization (ZLS-CF) or after crystallization (ZLS-G) and polishing (ZLS-P)] (n=12) and 5000 thermocycles were applied. Three sets of measurements were performed before and after aging to determine the color coordinates and surface roughness (Ra) by using a colorimeter and profilometer, respectively. The mean surface roughness (Ra) values were calculated. Color differences and translucency parameter (TP) values were calculated using the color difference ΔEab and TP formulas. ANOVA was used to analyze the color difference, translucency, and surface roughness values (α=.05). Results: Significant differences in the ΔE values were not observed (P=.736) for specimens with different types of surface finishing. A significant difference was observed between the translucency values for different surface finishing groups before aging (P&lt;.001). A significant difference in the surface roughness data between samples with different kinds of surface finishing was observed both before and after aging (P&lt;.001). The ZLS-P group exhibited lowest surface roughness values before and after aging (P&lt;.001). A positive significant correlation between the ΔE and translucency change values was observed in both the ZLS-G (P=.005) and ZLS-P (P&lt;.001) groups. Conclusions: The surface finishing type did not affect the color change of ZLS glass-ceramic. The translucency values for different surface finished ZLS glass-ceramic specimens changed before aging. After aging, the surface finishing did not affect the translucency of ZLS glass-ceramic. All tested groups exhibited surface roughness values higher than the plaque accumulation threshold (Ra=0.2 mm)

Clinical factors affecting the translucency of monolithic Y-TZP ceramics

The use of monolithic yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramics in aesthetically critical regions is questionable because of the insufficient translucency and opacity of the restorations. Intrinsic (manufacturing process) and extrinsic factors (laboratory procedures and clinical factors) can affect the translucency of monolithic zirconia. In this narrative review, the clinical factors (thickness, cementation type, colour of the monolithic zirconia, surface finishing methods and wear, dental background, cement colour, low temperature degradation) affecting the translucency of monolithic Y-TZP ceramics were reported

Effect of thermocycling on the surface properties of resin-matrix CAD-CAM ceramics after different surface treatments.

PURPOSE To evaluate the effect of thermocycling on the water contact angle (WCA), surface roughness (SR), and microhardness (MH) of resin-matrix computer-assisted design and computer-assisted manufacturing (CAD-CAM) ceramics after different surface treatments (conventional polishing or 2 different surface sealants). MATERIAL AND METHODS Two different types of resin-matrix CAD-CAM ceramics; a nanoparticle-filled resin (CeraSmart; CS) and a resin nanoceramic (Lava Ultimate; LU) were tested. Rectangular-shaped plates (1 mm-thick) were divided into 3 groups (n = 8) in terms of surface treatment methods applied: conventional polishing (control) or 2 surface sealants (Optiglaze (OG) and Palaseal (PS)). Scanning electron microscope images ( × 1000 and × 700 magnifications) of each material were taken from 2 additional specimens before surface treatments. After surface treatments, WCAs of deionized water, SR, and MH values of specimens were measured. All specimens were subjected to 5000 thermocycling and measurements were repeated. SR, WCA, and MH data before and after thermocycling were compared by using a 2-way ANOVA (α=.05). RESULTS A significant interaction was found between the surface treatment and the material for WCA after thermocycling (P  0.05). CONCLUSIONS Thermocycling affected the SR, MH, and WCA of all resin-matrix CAD-CAM ceramics

Farklı sinterleme programları ve yüzey işlemlerinin monolitik zirkonya seramiğin faz transformasyon ve kırılma dayanım üzerindeki etkisinin incelenmesi

AMAÇ: Farklı sinterleme programları ve yüzey işlemlerinin monolitik zirkonyanın yüzey özellikleri, faztransformasyon ve bükülme dayanımı üzerindeki etkisinin incelenmesidir.GEREÇ VE YÖNTEM: Monolitik zirkonya örnekler (n=168) sinterleme programına göre 3 gruba (klasik, hızlı,süper hızlı) ayrıldı (n=56). Sinterleme sonrasında her gruptan 1’er örnek tane boyutu analizinde kullanıldı. Kalanörnekler yüzey işlemlerine göre 5 gruba (kontrol, polisaj, glaze, aşındırma+polisaj, aşındırma+glaze) ayrıldı(n=11). Sonrasında her gruptan 1’er örnek SEM ile incelendi. Kalan örnekler termal olarak yaşlandırıldı. Örneklerinyüzey pürüzlülük, monoklinik faz içerik/hacim ve 3-nokta bükülme dayanım değerleri ölçüldü. Monoklinik faziçerik/hacim ve yüzey pürüzlülük değerleri Kruskal-Wallis ve Dunn testi ile, bükülme dayanım değerleri 2-yönlüANOVA ve Weibull analizi ile ve gruplar arasındaki ilişki Spearman korelasyon analizi ile incelendi.BULGULAR: Tane boyutu klasik sinterlemeden, hızlı ve süper hızlı sinterlemeye doğru gidildikçe küçüldü. SEM’egöre, tüm sinterleme gruplarında glaze ve aşındırma+glaze düzgün yüzey yapısı gösterdi. Monoklinik faz içerik/hacim değerleri sinterleme, yüzey işlem ve sinterlemeXyüzey işlem tipinden (p≤0.001) ve yüzey pürüzlülükdeğerleri yüzey işlem tipinden etkilendi (p&lt;0.001). Tüm sinterleme gruplarında, yüksek monoklinik faz içerik/hacim değerleri aşındırma+polisaj ve aşındırma+glaze; düşük yüzey pürüzlülük değerleri glaze, aşındırma+polisajve aşındırma+glaze’de gözlendi. Bükülme dayanım değerleri sinterleme ve yüzey işlem tipinden etkilenmedi.Weibull analizine göre tüm grupların m ve σo değerleri için anlamlı bir farklılık bulunmadı. Hızlı aşındırma+glaze(r=0.674, p=0.033) ve süper hızlı polisaj grubunun (r=0.747, p=0.013) monoklinik faz içerik/hacim-pürüzlülükdeğerleri arasında korelasyon belirlendi.SONUÇ: Monolitik zirkonya için üç sinterleme programı kullanılabilir. Yüzey işlem tipi sinterleme program tipinegöre seçilmelidir. Genel olarak değerlendirildiğinde, glaze ve aşındırma+glaze yüzey işlemi olarak önerilebilirAIM: To investigate the effect of different sintering programs and surface treatments on surface properties, phasetransformation and flexural strength of monolithic zirconia.MATERIAL AND METHOD: Monolithic zirconia specimens (n=168) were divided into 3 groups (classical, speed,super speed) according to sintering program (n=56). After sintering, 1 sample from each group was used for grainsize analysis. Remaining samples were divided into 5 groups (control, polish, glaze, grind+polish, grind+glaze)according to surface treatments (n=11). Then, 1 sample from each group was analyzed by SEM. Remainingsamples were thermally aged. Surface roughness, monoclinic phase content/volume and 3-point flexural strengthvalues of samples were measured. Monoclinic phase content/volume and surface roughness values by Kruskal-Wallis and Dunn test, flexural strength values by 2-way ANOVA and Weibull analysis and relationships betweengroups by Spearman’s correlation analysis were analyzed.RESULTS: Grain size decreased from classical sintering to speed and super speed sintering. According to SEM,in all sintering groups glaze and grind+glaze showed smooth surface structure. Monoclinic phase content/volumevalues were affected by sintering, surface treatment and sinteringXsurface treatment type (p≤0.001) and surfaceroughness values were affected by surface treatment type (p&lt;0.001). In all sintering groups, high monoclinicphase content/volume values in grind+polish and grind+glaze; low surface roughness values in glaze, grind+polishand grind+glaze were observed. Flexural strength values were not affected by sintering and surface treatmenttype. According to Weibull analysis, no significant difference was found for the m and σo values of all groups.Correlation was determined between monoclinic phase content/volume-roughness values of speed grind+glaze(r=0.674, p=0.033) and super speed polish (r=0.747, p=0.013) groups.CONCLUSION: Three sintering programs can be used for monolithic zirconia. Type of surface treatment shouldbe selected according to sintering program type. When evaluated in general, glaze and grind+glaze can berecommended as a surface treatment.</p

Effect of multiple firings on surface roughness and flexural strength of CAD-CAM ceramics

© 2022 Editorial Council for the Journal of Prosthetic DentistryStatement of problem: Knowledge on the effect of multiple firings on surface roughness and the flexural strength of different types of monolithic computer-aided design and computer-aided manufacturing (CAD-CAM) ceramics is limited. Purpose: The purpose of this in vitro study was to evaluate the effect of multiple firings on the surface roughness and flexural strength of 4 different CAD-CAM ceramics after thermocycling. Material and methods: Four different CAD-CAM ceramics (Lava All Zirconia 3-mol yttria tetragonal zirconia polycrystal [3-YTZP] [Z], VITA SUPRINITY [S], IPS e.max CAD [EX], IPS Empress CAD [E]) (n=33) were wet-sectioned to form rectangular 18×4×1.2-mm specimens. After glaze application, the specimens were divided into 3 subgroups according to the number of firings (1, 2, and 4) (n=11). The specimens were thermocycled (10 000 cycles), and surface roughness and flexural strength values were measured (n=10). One additional specimen from each group was analyzed by using scanning electron microscopy (SEM). Data were analyzed by 2-way analysis of variance (ANOVA) and the Tukey honestly significance difference (HSD) test (α=.05). Results: According to the 2-way ANOVA, the material, number of firings, and the interaction between the material and number of firings affected the surface roughness (P<.001). For flexural strength, material (P<.001) and number of firings (P<.039) were found significant. Multiple firings (2 or 4 firings) affected the surface roughness of E (P<.001). Regardless of the number of firings, the Z material had the highest flexural strength (P<.001). Four firings affected the flexural strength values only for the Z material (P≤.005). Conclusions: CAD-CAM ceramic type affected the surface roughness and flexural strength values. The surface roughness of E was lower when fired 2 or 4 times than when fired once. The flexural strength of Z was lower when fired 4 times than when fired once

Effect of firing cycle and aging on long-term chemical degradation of monolithic CAD-CAM ceramics

© 2022 Editorial Council for The Journal of Prosthetic DentistryStatement of problem: Previous studies have shown the susceptibility of dental ceramics to degradation when subjected to certain media. However, knowledge on the effect of repeated firings and thermocycling on the ion elution of computer-aided design and computer-aided manufacturing (CAD-CAM) ceramics is lacking. Purpose: The purpose of this in vitro study was to compare the effect of repeated firings on the ion elution of CAD-CAM materials before and after thermocycling. Material and methods: Bar-shaped specimens were prepared from 4 different CAD-CAM materials (monolithic zirconia [Z], zirconia-reinforced lithium silicate glass-ceramic [S], lithium disilicate glass-ceramic [EX], and leucite-reinforced glass-ceramic [E]) and divided into 3 groups according to the number of repeated glaze firings (1 firing [1F], 2 firings [2F], and 4 firings [4F]). Specimens were placed into deionized water (pH 7.4) and stored at 37 °C for 168 hours. Inductively coupled plasma-optic emission spectrophotometry (ICP-OES) was used to measure the baseline values of the eluted ions in immersion. The specimens were then subjected to thermocycling. Then, surface roughness (Ra) and ion elution values were measured. The Kruskal-Wallis and Mann-Whitney U tests were used to analyze the ion elution data before and after thermocycling, and the effect of thermocycling on ion elution was assessed by the Wilcoxon signed rank test. Ra data were analyzed with 2-way analysis of variance (ANOVA) and the Tukey honestly significant difference tests (α=.05). Results: Elution of some ions varied depending on the material-firing pair before (Al, As, B, Ba, Cr, Cu, Li, Mg, Na, P, and Zn) and after (Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, K, Li, Mg, Na, P, Y, and Zn) thermocycling. Before thermocycling, all firing groups within each material showed a similar number of significantly higher eluted ions. After thermocycling, the number of significantly higher eluted ions decreased in all materials, except for EX. The effect of thermocycling on the ion elution of the 1F group of Z (Al, Be, Ca, Cd, Co, Cr, Cu, K, Li, P, Y, and Zn), S (As, Be, Cd, Co, Cr, K, P, and Y), EX (B, Cu, and P), and E (B and Ba); 2F group of Z (Al, Be, Ca, Co, Cr, Cu, K, Li, P, and Y), S (Be, Cd, Co, K, Li, and Y), EX (P), and E (P); 4F group of Z (Al, As, Ba, Be, Ca, Cd, Co, Cr, Cu, K, Li, P, and Y), S (Al, Be, Cd, Co, Cr, Li, Mg, and Y), EX (Be, Ca, Cd, Co, K, Y, and Zn), and E (Ca and P) was nonsignificant (P≥.051). The interaction between material and repeated firings (P<.001) had a significant effect on Ra. For 1F groups, E showed the highest Ra (P≤.003), while Z had higher Ra than S (P=.009). For 2F groups, Z had higher Ra than S (P=.01). The differences among 4F groups were nonsignificant (P≥.677). An increased number of repeated firings (2F and 4F) decreased the Ra of E (P<.001). Conclusions: The effect of repeated firings and thermocycling on the chemical stability of the tested CAD-CAM materials varied. No clear trend was observed on the elution of different ions within material-firing pairs before thermocycling. However, thermocycling increased the number of significantly higher eluted ions for EX. The effect of thermocycling on the ion elution of materials varied depending on ions. Repeated firings decreased the surface roughness of E

The effects of nutritional habits on leucite-based ceramic repaired with nanohybrid composites

The purpose of the present in vitro study was to evaluate the effects of nutritional habits (various liquids) on the color change and early repair bond strength of a leucite-based ceramic repaired with different contents of nanohybrid composite resins currently used by the clinicians. Ninety-six IPS-Empress CAD ceramic samples were obtained with low-speed diamond saw. For all samples same repair method was performed. Samples were divided into groups according to four nanohybrid composite resins used as a repair material: Tetric-N-Ceram Bulk Fill, Filtek Z550, Clearfil-Majesty Esthetic, Bisco-Aelite Aesthetic Enamel (n = 24). Composite resins were applied on ceramic surface and polymerized (40 sec). After waiting for 24 h, samples were divided into three subgroups according to liquid types: pomegranate-flavored mineral water, salad dressing, and distilled water (n = 8). Before and after immersion the samples in the various liquids, color measurements were calculated (24 h). Then, shear bond strength was tested with an universal testing machine.For the statistical analyses two-way ANOVA, Tukey HSD, Spearman's correlation tests were used at a significance of p 0.05). When a composite resin is selected as a repair material, nutritional habits of the patient should be taken into consideration. Although hydrophilic monomer type of a composite material is a more predominant factor associated with color change, filler weight has the same predominant effect on shear-bond strength