Faik Tugut

Investigation of bonding properties of denture bases to silicone-based soft denture liner immersed in isobutyl methacrylate and 2-hydroxyethyl methacrylate

PURPOSE The purpose of this study was to investigate the bonding properties of denture bases to silicone-based soft denture liners immersed in isobutyl methacrylate (iBMA) and 2-hydroxyethyl methacrylate (HEMA) for various lengths of time. MATERIALS AND METHODS Polymethyl methacrylate (PMMA) test specimens were fabricated (75 mm in length, 12 mm in diameter at the thickest section, and 7 mm at the thinnest section) and then randomly assigned to five groups (n=15); untreated (Group 1), resilient liner immersed in iBMA for 1 minute (Group 2), resilient liner immersed in iBMA for 3 minutes (Group 3), resilient liner immersed in HEMA for 1 minute (Group 4), and resilient liner immersed in HEMA for 3 minutes (Group 5). The resilient liner specimens were processed between 2 PMMA blocks. Bonding strength of the liners to PMMA was compared by tensile test with a universal testing machine at a crosshead speed of 5 mm/min. Data were evaluated by 1-way ANOVA and post hoc Tukey-Kramer multiple comparisons tests (α=0.05). RESULTS The highest mean value of force was observed in Group 3 specimens. The differences between groups were statistically significant (P<.05), except between Group 1 and Group 4 (P=.063). CONCLUSION Immersion of silicone-based soft denture liners in iBMA for 3 minutes doubled the tensile bond strength between the silicone soft liner and PMMA denture base materials compared to the control group.

Effects of sandblasting and laser irradiation on shear bond strength of low-fusing porcelain to titanium.

PURPOSE To investigate the bond strength of low-fusing porcelain to commercially pure titanium (Ti) that was laser irradiated with different levels of energy and sandblasted. MATERIALS AND METHODS A total of 30 titanium rods (10 mm in length and 12 mm in diameter) were prepared. The rods were divided into three groups (n = 10) according to surface treatments: SB: sandblasted; L1: Nd:YAG laser irradiated at 100 mJ, 10 Hz, and 1 W; L2: Nd:YAG laser irradiated at 200 mJ, 10 Hz, and 2 W. After surface treatment, low-fusing porcelain was applied onto the titanium specimens according to the manufacturers instructions, and these specimens were stored in distilled water at 37°C for 24 h. The shear bond strength test was performed at a crosshead speed of 1 mm/min. In addition, Kruskal-Wallis and Mann-Whitney U-tests were used to compare the bond strength results (α = 0.05). SEM and EDS analysis were also performed for one specimen of each group after the shear bond strength test to evaluate the nature of the fracture surface. RESULTS Group L2 produced the highest shear bond strength among the groups. There was a statistically significant difference in shear bond strength between groups L1 and L2 (p < 0.001). Nevertheless, no significant difference was found between groups SB and L1. EDS analysis revealed that laser treatment reduced presence of oxygen on the surface of Ti. In contrast to the sandblasted specimens, laser-irradiated specimens showed predominantly adhesive failure. CONCLUSION Laser treatment may be an alternative method to sandblasting for enhancing the bond strength of low-fusing porcelain to commercially pure titanium.

The Effects of Some Drinks on Saliva pH

Objectives: The purpose of this study is to evaluate the effects of some drinks on saliva pH. Methods: Systemic and periodontally healthy individuals aged 18-23 years were included in the study. Individuals saliva pHs were measured three hours after breakfast. Three groups were set up to measure after 1 minute, 10 minutes and 30 minutes after drinks were drunk and the effects of Turkish coffee, cola, ayran and green tea on saliva pH were investigated. Results: The most pronounced pH changes occurred in the first group. The lowest pH values were reached when cola was consumed while the highest pH values were reached when green tea was consumed. Within the pH measurement time period, the drink group with the least tendency of pH value change was green tea. Conclusion: In order to prevent tooth decay, there is a need to raise awareness about conscious and controlled consumption of beverages that may lead to significant reductions in salivary pH.

Comparison of fracture resistance of endodontically treated teeth with MOD cavity using different techniques of fiber insertion

Objectives: The purpose of this study was to evaluate the effect of fiber by using different techniques on fracture resistance of endodontically treated molars with mesio-occlusal-distal (MOD) cavities. Materials and Methods: Forty extracted human molars were randomly assigned to four groups (n = 10). Teeth in Groups 2-4 received root canal treatment and a MOD cavity preparation. Group 1 served as control. Group 2 was restored with composite resin. In Group 3, the fiber was inserted into the cavities in buccal to lingual direction by coating the occlusal one-third of the buccal wall to the occlusal one-third of the lingual wall, and lastly, the teeth were restored with composite resin. In Group 4, the flowable resin was coated inside the cavities with the fiber, as Group 3 was before restoring teeth with composite resin. Compressive loading of the teeth was performed at a cross-head speed of 0.5 mm/min. Data were analyzed using one-way ANOVA and Tukey post-hoc tests. Results: Fracture resistance values of all the groups were compared; the differences between Groups 2 and 3 or Groups 2 and 4 were found to be statistically significant. Conclusions: As a result, use of the fiber under composite resin with a flowable resin increased fracture strength to MOD cavities.

Mandibular tam protez ölçü modellerinin üç boyutlu bir ölçüm yöntemiyle karşılaştırılması

Amac: Bu cal man n amacmandibular alveolar kret olculerinin stabilitesinin uc boyutlu bir olcum yontemiyle de erlendirilmesidir. Gerec ve Yontem: Bu cal mada 14 di siz hastadan al nan olculer kullan ld . Hastalar iki gruba ayr ld . Son olcu maddesi olarak birinci grupta cinko-oksid ojenol (ZOE), ikinci grupta polivinilsiloksan (PVS) kullan larak al nan olculerden ana modeller elde edildi. Ana modeller uzerinden modifiye ahsi ka k haz rlanarak hastalardan olcu alc s ile yeniden olculer al nd . Elde edilen modeller uzerinde s n r cizgileri tahmini olarak cizildi ve alveol kret uzerinde 14 referans noktas belirlendi. Ana modellerin foto raflar al nd (Nikon E2/E2s) ve 3 boyutlu goruntuleri elde edildi. Alveolar kret yuksekli i, protezin oturdu u alan n buyuklu u ve cevresel s n r cizgilerinin uzunlu u 3 boyutlu goruntuler uzerinde olculdu. Bulgular: Bu cal mada olcu alc s yla elde edilen modellerdeki olcum de erlerinin di erlerinden yuksek oldu u goruldu. Olcu alc s yla bundan du uk de erlerde olcum de erleri gosteren cinko-oksid ojenol olcu modelleri aras nda istatistiksel olarak anlamlbulunamad (p>0.05). Buna kar l k polivinilsiloksan ile elde edilen modellerin olcum de erlerinde alveolar kret yuksekli i istatistiksel olarak anlaml bir azalma gosterdi (p< 0.05). Sonuc: Olcu maddesinin alveolar mukoz membran uzerindeki etkileri membran n ozelliklerine ve ahsi ka k dizayn na ba lkalmaktad r. Bu yuzden desteksiz reziduel kretlere sahip mandibular tam protez hastalar nda olcu maddesinin ve olcu tekni inin secimi oldukca onemlidir. Mandibular tam protez olculerinin olcu alc s ve cinko-oksid ojenol olcu maddesi ile al nmas onerilmektedir