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WOS:000585175400005 PubMed: 33149849 PURPOSE. The present study aimed to evaluate the clinical applicability of monolithic zirconia (MZ) crowns of different thickness via determination of fracture resistance and marginal fit. MATERIALS AND METHODS. MZ crowns with 0.5, 0.8, 1.0, and 1.5 mm thickness and porcelain fused to metal (PFM) crowns were prepared, ten crowns in each group. Marginal gaps of the crowns were measured. All crowns were aged with thermal cycling (5 - 55 degrees C/10000 cycle) and chewing simulator (50 N/1 Hz/lateral movement: 2 mm, mouth opening: 2 mm/240000 cycles). After aging, fracture resistance of crowns was determined. Statistical analysis was performed with one-way ANOVA and Tukey's HDS post hoc test. RESULTS. Fracture loads were higher in the PFM and 1 mm MZ crowns compared to 0.5 mm and 0.8 mm crowns. 1.5 mm MZ crowns were not broken even with the highest force applied (10 kN). All marginal gap values were below 86 mu m even in the PFM crowns, and PFM crowns had a higher marginal gap than the MZ crowns. CONCLUSION. The monolithic zirconia exhibited high fracture resistance and good marginal fit even with the 0.5 mm thickness, which might be used with reduced occlusal thickness and be beneficial in challengingly narrow interocclusal space.

Objective: The aim of this study was to determinate of the effective time of different denture cleanser tablets on the removal of Candida albicans on various base resins. Materials and Methods: Conventional heat cured resin, high impact resin, autopolymerized resin, and polyamide resin were used. 160 samples were prepared for each resin type. The biofilm of C. albicans was formed on the resins and then exposed to alkaline peroxide tablet and enzymatic tablets for 3-5-10-20-40-80-160-200 minutes. Cell viability was assessed by MTT test. 3-way ANOVA was used for statistical analysis. Results: The effect of resin type, tablet type and application time on cell viability of C. albicans were found to be significant (p

Objective: An ideal aesthetic restoration should be morphologically and optically compatible with the natural teeth and, at the same time, biologically acceptable. The translucency of the restoration is the most important factor in achieving a natural tooth appearance. The aim of this study was to compare the translucency parameters (TPs) of two types of monolithic computer-aided design/computeraided manufacturing (CAD/CAM) ceramics, Vita Suprinity HT (VS) and IPS e.max CAD HT (IPS), after utilizing three different surface finishing methods and being exposed to cola, coffee, and black tea solutions. Materials and Methods: A total of 24 groups consisting of 10 samples each were created from VS and IPS e.max CAD ceramics. Glaze, Shofu polishers, and Sof-lex polishing discs were used to finish the surface of the ceramics. Cola, coffee, and black tea were used as coloring solutions. For the control groups, samples were kept in distilled water. The TP was determined for optical properties. Data were statistically analyzed using three-way analysis of variance (ANOVA). The Bonferroni test was used for multiple comparisons. Results: Material, method, group and interaction effects were found statistically significant (p

WOS:000489084300022 PubMed: 31231108 To improve the flexural strength and flexural modulus of polymethyl methacrylate (PMMA), copolymerization of PMMA with 10, 20, 30, and 40% (v/v) of either ethyl-methacrylate, butyl-methacrylate (BMA), or isobutyl-methacrylate (IBMA) was carried out. Test specimens were fabricated from heat-cured resin. The flexural strength was measured using a 3-point bending test. The chemical characterization and the copolymerization mechanisms of the copolymer resins were confirmed by H-1-NMR and FTIR. The flexural strength data were analyzed by applying two-way variance analysis. PMMA was reinforced by ethyl-methacrylate, BMA and IBMA copolymerization. Flexural strengths of the BMA and IBMA copolymers were significantly higher than those of the control group. Maximum flexural strength and modulus resulted from a 40% concentration of IBMA. The flexural strength and modulus values of all copolymer groups were found to be higher than those of the control group. The flexural moduli of the BMA and ethyl-methacrylate groups were similar to those of the control.

The present study aimed to evaluate the antimicrobial effect of gaseous ozone against specific oral pathogens on denture base resins. 1080 round samples were prepared (10mm-diameter, 2mm-thickness). Candida albicans, Streptococcus mutans, Streptococcus gordonii, and Aggregatibacter actinomycetemcomitans, polyamide-Deflex, heat-cured polymethyl-methacrylate (PMMA)-QC-20, and cold-cured-PMMA-Meliodent. The doses and durations: 25, 50 and 100 mu g/ml, 5, 10, 20, 30 minutes. For Cell viability (CV) MTT was used. 100 mu g/ml was most effective dose for C. albicans, S .gordonii, and A. actinomycetemcomitans were in heat-cured-PMMA and polyamide for S.mutans. For polyamide, lowest CV was 43% in S.mutans and A.actinomycetemcomitans. CV of heat-cure and cold-cure PMMA were 31% and 32% in S.gordonii, respectively. CV was similar for all resins and durations in S.mutans and A.actinomycetemcomitans and for polyamide for C.albicans and for heat-cure PMMA for S.gordonii. 30-min ozone application killed 80% of all microorganisms in all resins except for C.albicans in polyamide (65% cell death) and cold-cure PMMA (57% cell death). Optimal dose/duration combination was 100 mu g/ml-10 min. Gaseous ozone can be considered as an effective cleansing agent for denture base resins.

Objective: Bone deficiency and other anatomical limitations might compromise dental implant surgery. Short implants are the easiest way to overcome this issue. The purpose of this study was to investigate survival rates of short dental implants versus long implants. Material and Methods: The study population included 137 patients treated with removable or fixed dentures supported by 548 dental implants. Data were analyzed to obtain survival rates in terms of age, gender, tobacco use, bony architecture, and prosthetic treatment style. Statistical analyses were carried out using Mann-Whitney U, Kruskal Wallis H, and chi-square tests. Results: The cumulative survival rate of short implants was 97.6% with 25.18 months of follow up. Elderly patients (>60 years old) had a lower implant survival rate than younger patients (p0.05). In addition, there were no significant differences in implant survival rates between short (6 mm) and long (11 mm) dental implants after 25.18 months (p>0.05). Conclusions: Although there are some limitations of the present study, the conclusion can be made that short implants have similar survival rates compared to long implants. However, further studies with longer follow-up periods should be conducted. Amaç: Kemik eksikliği ve diğer anatomik sınırlamalar, dental implant cerrahisini tehlikeye atabilir. Kısa implantlar, bu sorunun üstesinden gelmenin en kolay yoludur. Bu retrospektif çalışmanın amacı, kısa implantların uzun implantlara karşı sağkalım oranlarını karşılaştırmaktır. Gereç ve Yöntemler: Çalışma popülasyonu, 548 diş implantı ile desteklenen sabit veya çıkarılabilir protezlerle tedavi edilen 137 hasta idi. Veriler cinsiyet, yaş, sigara kullanımı, cerrahi işlem, kemik kalitesi ve protez restorasyon tipine göre sağkalım oranları elde etmek için değerlendirildi. İstatistiksel analizler ki-kare, Mann-Whitney U ve Kruskal-Wallis H-testleri kullanılarak yapıldı. Bulgular: Kısa implantların sağkalım oranı 25,18 aylık takip süresiyle %97,6 idi. Yaşlı hastalar (60 yaş üstü hastalar) diğer yaş gruplarından daha düşük bir sağkalım oranına sahipti (p0,05). Yaklaşık 25,18 aylık takip sonrasında kısa (6 mm) ve uzun (11 mm) diş implantları arasında implant sağkalımında anlamlı bir fark yoktu (p> 0,05). Sonuçlar: Bu çalışmaya göre kısa implantların uzun implantlara kıyasla benzer sağkalım oranlarına sahip olduğu sonucuna varılabilir. Bununla birlikte, daha uzun takip süreleriyle daha ileri çalışmalar yapılmalıdır.

Bilmek onemlidir, bildigini anlatmak daha onemlidir. Gecmisten gunumuze bilgilerin, sozlerin kayda alinmasi amaci ile ‘Soz ucar yazi kalir’ denmistir. Bilgilerimizi bizden sonraki kusaklara iletmenin en etkili yolu kitaplardir. Ozellikle ogrenciler basta olmak uzere akademisyenlerin de dogru bilgiye ulasmasi kitaplarla saglanir. Tum akademik hayatimiz boyunca calismalarimizda bize rehberolan kitaplar bizim icin olmazsa olmazlardandir. Kitap ya ilgilendigimiz konularla ya da ihtiyac duyulan konularla hayat bulur. Defekt protezleri, tam olarak odaklandigimiz bolgelerin bir miktar disina cikmaktadir. Her fakultede,Protetik Dis Tedavisi Anabilim Dalinda, cene-yuz protezi ile ilgilenen kisi sayisi genellikle azdir. Defekt protezlere ilgi, ya danisman yonlendirmesiyle ya da ilgiyle olusur.

Objective: The purpose of this study is to determine the effects of polishing techniques on color stability and surface roughness of lithium disilicate glass ceramic (LDC) and zirconia-reinforced lithium silicate ceramic (ZLS). Materials­and­Methods: Two hundred forty disks of LDC and ZLS were prepared. Glazing with the ceramics’ own glazing procedure, a series of sof-lex polishing discs and abrasive stones were used as the different polishing groups. Color differences (?E*) was evaluated by spectrophotometer, initial and after 48 hours of immersion in various solutions (n=10). Surface roughness (Ra) was evaluated by profilometer (n=10). Data were analyzed by Two-Way ANOVA, and Mann-Whitney U test. Results: No significant difference in ?E* values was observed between the sof-lex groups and abrasive stone groups (p>0.05) on LDC. ?E* values were significantly different with glazed, and abrasive stone groups than sof-lex groups (p0.05). The highest Ra value in ZLS was observed in group sof-lex. No significant difference was observed among group abrasive stone and sof-lex in LDC specimens (p>0.05). Conclusion: The amount of staining in the polished ZLS samples was more than the LDC samples. The coffee was determined as the most colorant solution. Abrasive stone may be used instead of sof-lex for polishing of LDC specimens. Amaç: Bu çalışmanın amacı, polisaj tekniklerinin lityum disilikat cam seramik (LDC) ve zirkonya ile güçlendirilmiş lityum silikat seramiklerin (ZLS) renk stabilitesi ve yüzey pürüzlülüğüne etkilerini belirlemektir. Gereç ve Yöntemler: LDC ve ZLS’den 240 disk hazırlanmıştır. Farklı polisaj grupları olarak seramiklerin kendi glaze prosedürü, sof-lex polisaj diskleri ve aşındırıcı taşlar kullanılmıştır. Renk farklılıkları (?E*), 48 saat çeşitli solüsyonlarda bekletilme öncesinde ve sonra spektrofotometre ile değerlendirilmiştir (n=10). Yüzey pürüzlülüğü (Ra) profilometre ile değerlendirilmiştir (n=10). Veriler çift-yönlü ANOVA ve Mann-Whitney U testi ile analiz edilmiştir. Bulgular: LDC için sof-lex grupları ve aşındırıcı taş gruplarının ?E* değerleri arasında anlamlı fark bulunmamıştır (p>0,05). ZLS için gleyz ve aşındırıcı taş gruplarının ?E* değerleri sof-lex gruplarından anlamlı fark göstermiştir (p0,05). ZLS için en yüksek Ra değeri sof-lex grubunda gözlenmiştir. LDC örnekler için aşındırıcı taş ve sof-lex grupları arasında önemli fark gözlenmemiştir (p>0,05). Sonuç: Polisaj yapılmış ZLS örneklerdeki boyanma miktarı LDC örneklerden fazla bulunmuştur. Kahve en boyayıcı solüsyon olarak tespit edilmiştir. LDC örneklerin polisajında aşındırıcı taş, sof-lex yerine kullanılabilir.

Background: The aim of this study was to evaluate the fracture resistance and wear amounts of different zirconia and metal-supported ceramics. Methods: Katana, Prettau, Zenostar, InCoris TZI, BruxZir and porcelain fused to metal (PFM) were used (n=10). All samples were aged via thermal-cycling. Wear test was performed in chewing simulator. Occlusal wear was measured via a 3D laser-scanner. Fracture resistance of samples was determined via a universal testing machine. For statistics, One-Way ANOVA and Tukey were used. Results: PFM had the highest wear area, and differences among groups were significant. BruxZir, Zenostar, and InCoris TZI had lower wear than Prettau and Katana, but the differences were not significant. All groups had similar wear volume. Fracture resistance was significantly lower in Katana and PFM than Zenostar, InCoris TZI, and Prettau. The difference between Katana and PFM was significant. BruxZir samples were not broken even with the highest force applied. Conclusions: Monolithic zirconia ceramics showed superior wear behavior compared to PFM in terms of wear area; however 3D wear measurements were similar. Fracture resistance was also higher in zirconia except for Katana, which had the lowest value. BruxZir was the hardest material with the lowest wear and highest fracture resistance.

WOS:000423209900001 PubMed: 29364341 Objective: Although the effectiveness of chemical cleansing against Candida albicans biofilm has been shown, the effective concentration of denture cleanser tablets has not been studied. The aim of this study was to assess the effect of three denture materials against Candida albicans biofilm and to determine effective concentrations of denture cleanser tablets. Material and methods: The surface-roughness of Acron-hi (TM), QC-20 (TM) and Deflex (TM) (n = 45 per resin) resins was standardized by using a profilometer and their contact angle or surface free energy was calculated. C. albicans biofilm was formed on all three resins and were treated with Polident 3 min (TM), Corega (TM) and Fittydent (TM) cleanser solutions at various concentrations and both resin-biofilm and cleanser-biofilm interest were determined by using a MTT protocol according to the European Committee on Antimicrobial Susceptibility Testing's antifungal susceptibility testing (AFST-EUCAST). Scanning electron microscopy was used to compare the efficacy of different resin materials against C. albicans biofilm. Anticandidal activity and surface free energy statistical parameters were calculated by using 3-way and 1-way ANOVA, respectively (p< 0.05). Results: Polident 3 min (TM) and Corega (TM) tablets significantly inhibited (p< 0.05) the proliferation of C. albicans against all denture resins at 27-37 mg/mL. Scanning electron microscopy results indicated that there was no significant difference among resin specimens regarding biofilm formation on dentures. We failed to find a significant relationship between surface free energy and the anticandidal effect of resin types. However, the polarity value of the resins was statistically associated with their anticandidal activity. Conclusions: The polarity of the resins, the concentrations of tablets and the chemical content of the cleanser may directly affect C. albicans biofilm formations. Polident 3 min (TM) and Corega (TM) tablets should be suggested for patients who use any denture resin types, whereas the Fittydent (TM) tablet should only be proposed for those who use Deflex (TM), when two tablets are dropped into 150 mL water.

Aim: In elderly individuals, infection control is, essential, especially in the presence of severe bacteria such as oral environment. Prevention of biofilm formation in removable dental prosthesis, which is often used in elderly patients might help infection control. This study aimed to evaluate the time-dependent effect of an enzymatic tablet on six microorganisms cultured in two different denture base resins.Material and Methods: Polymethylmethacrylate (PMMA) and polyamide-resin were used in this study. 480 samples were prepared for each resin, and denture cleanser tablet was tested against C.albicans, S.mutans, S.gordonii, A.actinomycetemcomitans, S.aureus, and E.coli for 3rd, 5th, 10th, 20th, 40th, 80th, 160th, and 200th minutes. Cell viability (CV) was evaluated by MTT. ANOVA was used for statistics. Results: C.albicans exhibited higher CV in polyamide-resin compared to PMMA-resin in all tested durations. S.gordonii and A.actinomycetemcomitans exhibited higher CV in PMMA-resin except for 80th minute-S.gordonii, which had similar values. S.mutans had a higher CV in PMMA-resin than polyamide-resin at 3rd, 5th, 10th, 160th, and 200th minutes, and other values were similar to polyamide-resin. The tested concentration killed more than 75% of microorganisms except for 3rd and 5th minute-C.albicans on resins. S.aureus and E.coli had similar. CV of microorganisms on PMMA-resin was higher than on polyamide-resin. All microorganisms exhibited different adherence on the resins.Conclusions: Tablet cleanser was effective in all microorganisms and durations and over 10-minute durations provided over 76% cell death. Patients with a compromised immune system can safely use restorations composed of polyamide-resin or PMMA-resin with 40 min-treatment of tablet cleanser.Keywords: Bacteria; candida albicans; cell survival; denture bases; denture cleansers.

Aim: This study aimed to determine the cytotoxicity of polymethylmethacrylate copolymers.Material and Methods: The polymethylmethacrylate resin was used to fabricate the samples. Ethyl-methacrylate, butyl-methacrylate and isobutyl-methacrylate, were used to form the copolymerization of polymethylmethacrylate. 10%-20%-30%-40% ethyl-methacrylate, butyl-methacrylate and isobutyl-methacrylate monomers were added to the methyl-methacrylate, which is the monomer of the control group, and 13 different groups were formed. Five specimens (n=5) for cytotoxicity test were prepared for each group. Cytotoxicity effects of the resins at 24th and 48th hours were evaluated by MTT assay. The data of the cytotoxicity test was analyzed by applying one-way variance analysis.Results: The effect of monomer type and monomer percent on cell viability was significant in both periods (p 0.01). The percentage of cell viability of all groups at both times was over 90%. The cell viability showed a tendency to decrease by increasing the percentage of monomer added in both periods. The highest and lowest cell viability in 24th hours were observed in 10% ethyl-methacrylate and 30% butyl-methacrylate groups respectively, while the highest and lowest cell viability in a 48th hour was observed in 10% butyl-methacrylate and 40% butyl-methacrylate groups, respectively.Conclusion: The cytotoxic effects of copolymer resins were not observed at 24th and 48th hours. Cell viability was found at more than 90% in both periods. It was shown that the copolymer resins formed by the addition of 10%, 20%, 30%, and 40% by volume of isobutyl-methacrylate, butyl-methacrylate, and ethyl-methacrylate to the methyl-methacrylate were biocompatible materials.Keywords: Acrylic resins; cell survival; cytotoxicity tests, immunologic; denture bases; polymers.