The effect of silane applied to glass ceramics on surface structure and bonding strength at different temperatures

PURPOSE: To evaluate the effect of various surface treatments on the surface structure and shear bond strength (SBS) of different ceramics. MATERIALS AND METHODS: 288 specimens (lithium-disilicate, leucite-reinforced, and glass infiltrated zirconia) were first divided into two groups according to the resin cement used, and were later divided into four groups according to the given surface treatments: G1 (hydrofluoric acid (HF)+silane), G2 (silane alone-no heat-treatment), G3 (silane alone-then dried with 60℃ heat-treatment), and G4 (silane alone-then dried with 100℃ heat-treatment). Two different adhesive luting systems were applied onto the ceramic discs in all groups. SBS (in MPa) was calculated from the failure load per bonded area (in N/mm2). Subsequently, one specimen from each group was prepared for SEM evaluation of the separated-resin–ceramic interface. RESULTS: SBS values of G1 were significantly higher than those of the other groups in the lithium disilicate ceramic and leucite reinforced ceramic, and the SBS values of G4 and G1 were significantly higher than those of G2 and G3 in glass infiltrated zirconia. The three-way ANOVA revealed that the SBS values were significantly affected by the type of resin cement (P<.001). FIN ceramics had the highest rate of cohesive failure on the ceramic surfaces than other ceramic groups. AFM images showed that the surface treatment groups exhibited similar topographies, except the group treated with HF. CONCLUSION: The heat treatment was not sufficient to achieve high SBS values as compared with HF acid etching. The surface topography of ceramics was affected by surface treatments.

Etiologic agents of cervicovaginitis in Turkish women

To investigate the distribution of microbiologic agents causing cervicovaginitis. We conducted the study between October 2002 and December 2004 in Abant Izzet Baysal University, Duzce School of Medicine Hospital, Turkey. The samples were obtained from the posterior vaginal fornix and cervix by swabs in 828 patients. Direct microscopic examination, culture and enzyme immune assay [EIA] methods were performed in all patients for diagnosis of microbiologic agents. Gardnerella vaginalis [G. vaginalis] were diagnosed in 254 [30.7%] patients, Candida albicans [C. albicans] in 152 [18.4%], Candida glabrata [C. glabrata] in 36 [4.3%], Candida species in 52 [6.3%], Staphylococcus aureus [S. aureus] in 62 [7.5%], Streptococcus group B in 28 [3.4%], Escherichia coli [E. coli] in 42 [5.1%], Klebsiella species in 24 [2.9%], and Streptococcus group D in 8 [1%] patients in culture. Less frequent enterobacteria in 30 [3.6%] were: Pseudomonas species, Proteus species Enterobacter species, Hafnia alvei and Nonfermenter species. Neisseria gonorrheae [N. gonorrheae] was detected in one patient [0.1%] in culture. The Chlamydia trachomatis [C. trachomatis] antigen was detected by EIA methods in 130 [15.7%] patients and Trichomonas vaginalis [T. vaginalis] was observed in 8 [1%] patients by direct microscopic examination. Performing the etiologic diagnosis of cervicovaginitis is necessary in order to take appropriate therapeutic and preventive measures. Therefore, we recommend G. vaginalis, C. albicans and C. trachomatis should be investigated in patients having a diagnosis of cervicovaginitis in our population, since these were detected in a considerable number of cases. Additionally, C. glabrata and T. vaginalis should be kept in mind as possible pathogens