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Biomedical subjects

N Unlü

Publications and source records attributed to N Unlü.

At least 19 recordsLinked to original sources
PubMed2005

Antibacterial activities of MDPB and fluoride in dentin bonding agents.

The aim of this study was to compare in vitro antibacterial activity of MDPB containing bonding system ABF with activities of three Fluoride containing bonding systems (Fuji Bond LC (FBLC), Prime&Bond NT (PBNT), and FluoroBond (FLB). Two bacterial strains were tested: Streptococcus mutans and Lactobacillus acidophilus. The study was performed on Muller Hinton Agar by Agar Well Technique. The bacterial agar was evenly distributed over the surface of petri dishes. Standard wells were punched into the agar. The test materials were placed in the wells of Muller Hinton agar plates, inoculated with Streptococcus mutans NCTC10449 and Lactobacillus acidophilus. The diameters of inhibition zones produced around the materials were measured after 24 h of incubation at 37 +/- 1 degrees C. For statistical analysis, Duncan's multiple range test was used. The primers of bonding agents were highly effective against to Streptococcus mutans. The MDPB containing primer of ABF Bond produced the greatest inhibition zones against to Lactobacillus acidophilus. It was followed by FLB primer. Lactobacillus acidophilus was resistant to FBLC primer and bonding, ABF, PBNT and FLB bonding agents. The results of this study indicated that, incorporation of MDPB in primer of self-etch system increased its antibacterial activity especially against to Lactobacillus acidophilus. However, all bonding systems except for bonding agent of ABF showed some antibacterial activity against to Streptococcus mutans.

Anti-Bacterial Agents↗
PubMed2004

Effect of home bleaching agents on the microhardness of human enamel and dentin.

In this study, the effects of home bleaching agents that contains carbamide peroxide (in different concentrations such as 10 and 15%) on the surface hardness of human enamel and dentine were evaluated. The buccal surfaces of 90 recently extracted human mandibular anterior teeth were used. The specimens in the dentine group were ground to expose of dentine surface. Then, samples in both enamel and dentine group were randomly divided into six main groups with 15 in each group. In the group 1 and 4, 15% carbamide peroxide was applied to the enamel and dentine surfaces and then the teeth were left in an incubator at 37 degrees C and 100% humidity for 4 h first, then left 28 h after repeating the same procedures seven times. The teeth were treated with 10% carbamide peroxide in groups 2 and 5 and distilled water in groups 3 and 6 (control groups), using the same procedures. Vicker's microhardness of enamel and dentine were assessed on each tooth before and after each treatment period (4 and 28 h). The hardness of control group specimens was also obtained after 4 h in distilled water and then after 28 h. For statistical analysis one-way ANOVA and post-hoc Tukey tests were used. For both 10 and 15%, there were no statistically significant differences between the untreated control specimens and the specimens treated with the bleaching materials for enamel and dentine at any given measurement time (P > 0.05). Nevertheless, in vivo use of bleaching agents on tooth hard tissues requires further analysis.

Carbamide Peroxide↗
PubMed2003

Comparison of antibacterial activity of two dentin bonding systems using agar well technique and tooth cavity model.

OBJECTIVE: This study compared the antibacterial activities of two dentin bonding systems (ABF, Kuraray and Reactmer Bond, Shofu) by a conventional agar well technique and a newly designed in vitro test using tooth model. METHODS: In the agar well technique, the test materials were filled in the wells of Muller Hinton agar plates inoculated with Streptococcus mutans NCTC10449, and the diameters of inhibition zones produced around the materials were measured after 24h of incubation. For the tooth model test, three cavities (diameter 1mm, depth 2mm) were prepared in the flat occlusal dentin of human extracted molar. After sterilization, the teeth were left in broth culture of 1.56 x 10(8)CFU/ml of S. mutans at 37 degrees C for 72h for allowing bacteria to invade the cavity. The dentin bonding systems were applied separately to each of the two infected cavities, and the third cavity was left unapplied for control. After sealing the occlusal surfaces, the teeth were kept in physiologic saline solution at 37 degrees C for 72h. The standardized amounts of dentin chips (120+/-5mg) were obtained from the cavity walls and the number of bacteria recovered was determined. The results were analyzed by One Way ANOVA, Kruskal Wallis and Mann-Whitney's U tests. RESULTS: The primer of ABF and Reactmer Bond produced inhibition zones with similar sizes (p>0.05), but the bonding resin of ABF did not produce any inhibition. When tested by the model cavity method, the application of ABF resulted in significantly less bacterial recovery than Reactmer Bond (p<0.05), demonstrating substantial antibacterial effects. CONCLUSIONS: The tooth model method used in this study was effective for evaluating the substantial antibacterial effects of dentin bonding agents, and the experimental dentin bonding system ABF was demonstrated to be able to inactivate the bacteria in the cavity effectively in comparison with little antibacterial activity shown by Reactmer Bond.

Agar↗
PubMed2003

Influence of dentinal regions on bond strengths of different adhesive systems.

This in vitro study assessed comparatively the shear bond strengths of three composite resins, 3M Valux Plus (3MVP), Herculite (H), Clearfil AP-X (CAP-X), a polyacid modified composite resin Dyract (D), and a resin modified glass-ionomer materials Vitremer (V), to cervical and buccal dentine regions of extracted human molar teeth. Four different bonding systems, 3M ScotchBond Multipurpose (SB), Clearfil Liner Bond 2 (LB2), Opti Bond (OB), and Prime & Bond 2.1 (PB 2.1) were used with the manufacturer's respective composite and compomer materials. One hundred freshly extracted mandibular molar teeth were selected for this study. Flat buccal dentine surfaces were created on 50 teeth and cylindrical rods of the five materials were bonded to the dentine surfaces. For assessment of cervical bond strengths, the materials were bonded to mesial and distal enamel bordered occlusal dentinal surfaces of the remaining 50 teeth. The five groups of restorative procedures were applied as follows; Group 1: SB + 3MVP, Group 2: LB2 + CAP-X, Group 3: OB + H, Group 4: PB2.1 + D, Group 5: Vitremer primer (VP) VP + V. Each restorative procedure thus had 20 specimens (10 buccal + 10 cervical). After 24 h of water storage (37 degrees C), the specimens were tested on a Universal Testing machine in shear with a cross head speed of 0.5 mm min-1. The bond strength values were calculated in MPa and the results were evaluated statistically using Kruskal-Wallis one-way/anova and Mann-Whitney U-tests. It was found that the bond strengths of SB + 3MVP, LB2 + CAP-X and VP + V to buccal dentine surfaces were significantly stronger (P < 0.05) than those to the occluso-cervical dentine floors. When the bond strengths to the occluso-cervical dentine and buccal dentine surface were compared, there was no significant difference between the materials (P > 0.05). Vitremer was found the least successful adhesive material in terms of shear bond strength on both buccal and occluso-cervical dentine surfaces.

Acrylic Resins↗
PubMed2003

The management of giant retinal tears with silicone oil.

PURPOSE: To report the surgical success of vitrectomy with silicone oil tamponade in the treatment of retinal detachment associated with giant retinal tears due to various factors. METHODS: We retrospectively evaluated 21 eyes of 21 patients with retinal tears 90 degrees or greater that underwent vitrectomy, with injection of perfluorocarbon liquids and silicone oil tamponade. Eight eyes (38.1%) had previous ocular surgery (4 aphakia-pseudophakia, 4 pars plana vitrectomy), 4 eyes (19.0%) had a history of trauma (blunt injuries in 2 and penetrating injury in 2), 3 (14.3%) had high myopia. Six eyes (28.6%) had no known condition predisposing to development of giant retinal tear. RESULTS: Retinal attachment was obtained in 17 (80.5%) of 21 eyes, with a mean follow-up of 12.5 months. Visual acuity improved in 15 eyes (71.4%). CONCLUSIONS: Pars plana vitrectomy with silicone oil tamponade proved highly effective in giant retinal tears in terms of anatomical and functional results.

Adolescent↗
PubMed2002

Bond strength of five current adhesives to caries-affected dentin.

Five current dentin adhesives were evaluated for their ability to bond to caries-affected dentin. The materials were: total etch [Solid Bond (SB)], two self-etch [Clearfil SE Bond (CSE), Etch and Prime (EP)], two one bottle [Prime and Bond 2.1 (PB), One Coat Bond (OCB)]. Sixty extracted molar teeth with proximal caries (mesial or distal) extending into mid-dentin were used. By grinding normal and caries-affected proximal surfaces, flat dentin surfaces were obtained. The surfaces were then bonded with each adhesive system and composite resins were added to the surfaces by packing the material into a cylindrical-shaped plastic matrix with an internal diameter of 2.5 mm and height of 3 mm. Shear bond testing was performed following 10 days incubation of specimens in distilled water at 37 degrees C. Results were analysed by Kruskal-Wallis ANOVA, and Mann-Whitney U multiple comparison test and Wilcoxon rank tests. The results obtained with CSE, SB, and EP were similar in caries affected and normal dentin (P > 0.05). But bonds made to normal dentin with OCB and PB were lower (P < 0.05) than bonds to caries-affected dentin. Bonding to caries-affected dentin with CSE (24.49 +/- 5.38), SB (21.49 +/- 9.15), and EP (21.19 +/- 9.17) showed shear bond strengths higher than OCB (17.43 +/- 9.78) and PB (14.10 +/- 7.94) (P < 0.05). Bonding to normal dentin with CSE (29.91 +/- 8.95) was the highest (P < 0.05). SB (21.17 +/- 5.41) and EP (17.45 +/- 6.21) showed shear bond strengths higher than OCB (11.99 +/- 10.15) and PB (10.57 +/- 4.56) (P < 0.05).

Acetone↗
PubMed2001

Effect of cavity varnish, amalgam liner or dentin bonding agents on the marginal leakage of amalgam restorations.

The purpose of this in vitro study was to compare marginal leakage of Class II amalgam restorations lined with different agents (two new generation dentin bonding systems, a cavity varnish and an amalgam liner). Forty freshly extracted human molar teeth were divided into five groups. Class II preparations were prepared in the mesial and distal surfaces of each molar. While the cavities in two groups were lined with two new generation bonding systems, the other two groups were treated with an amalgam lining material and a cavity varnish. Fifth group was used as control, without any lining. Amalgam* was hand-condensed into each preparation. Specimens were thermocycled, stained and sectioned. Microleakage was graded using a stereomicroscope. Mean microleakage scores for occlusal and cervical margins were calculated and analysed. For the leakage values on occlusal margins, Kruskal-Wallis test indicated no significant difference in all groups. For the leakage values on cervical margins, Kruskal-Wallis test indicated significant difference in four groups when compared with controls (P < 0.001). On the other hand, there was no significant difference between the occlusal and cervical leakage values in each group.

Calcium Fluoride↗
PubMed2001

Bonding strength to two different surfaces of dentin under simulated pulpal pressure.

PURPOSE: The purpose of this in vitro study was to measure and compare the in vitro shear bond strengths (SBS) of the following dentin bonding systems to different dentin surfaces under simulated pulpal pressure: Liner Bond 2 (self-etching) (LB2), Liner Bond 2V (self-etching) (LB2V), Opti Bond Solo (single component) (OBS), Fuji Bond LC (filled) (FBLC), Prime & Bond 2-1 (single component) (P&B2-1), and Solid Bond (total etching) (SB). MATERIALS AND METHODS: Occlusal and buccal surfaces of 60 extracted human molars were prepared to expose the dentin bonding surface. After being wet ground with 600-grit abrasive papers, teeth were randomly assigned to 6 equal groups of 10 each. The dentin surfaces were treated with the bonding systems mentioned above, and resin composite cylinders (Clearfil AP-X) were built up under simulated pulpal pressure when diluted bovine serum was used as the pulpal fluid. After one day of storage in 37 degrees C water, the specimens were shear tested to failure on an Instron machine. RESULTS: The data were statistically analyzed with the Student's t-test and a post hoc Tukey test. Comparing buccal surfaces, the post hoc Tukey test indicated no significant differences among all the test groups (p > 0.05). On occlusal surfaces, the post hoc Tukey test indicated significant differences among the tested groups (p < 0.05). The Student's t test revealed significant differences between the occlusal and buccal shear bond strength values in LB 2, LB2V, and SB groups (p < 0.05). CONCLUSION: The strength of adhesion to dentin depends upon both the adhesive system used - with self-etching systems tending to show higher bond strengths than the other materials tested - and the location of the dentin, with significantly higher SBS being found on buccal surfaces in 3 of the 7 tested bonding systems.

Acid Etching, Dental↗
PubMed1998

Comparison of the anti-inflammatory effects of diclofenac and flurbiprofen eye drops after cataract extraction.

PURPOSE: A clinical double-blind study was performed in patients who had undergone extracapsular cataract extraction and intraocular lens implantation (ECCE+IOL) to compare the anti-inflammatory effects of diclofenac sodium 0.1% and flurbiprofen 0.03% eye drops. METHODS: The diclofenac group included 21 eyes of 21 patients and the flurbiprofen group included 22 eyes of 22 patients. The parameters compared were pachymetry of the cornea, corneal surface changes, intraocular pressure (IOP) and the degree of inflammation of the anterior chamber at one, three and six weeks after cataract surgery. RESULTS: There was no statistically significant difference between the two treatment groups in corneal pachymetry, corneal surface changes, IOP and the anterior chamber inflammation (p>0.05). CONCLUSION: Both drugs were well tolerated and may be safely used to reduce inflammation for cataract surgery.

Aged↗
PubMed1998

The SRKII formula in the calculation of intraocular lens power.

This study compares the predictive accuracy of the SRKII formula for groups with average axial length and long eyes. 344 eyes which underwent cataract extraction with implantation of a posterior-chamber intraocular lens were included in the survey; 246 eyes had an average axial length (22.0-24.49 mm), and 98 eyes had an axial length of more than 24.50 mm. Mean absolute errors were 0.26+/-0.68 dpt in the first group and 1.16+/-1.78 dpt in the second group. 94.3% of the average eyes were within 1.0 dpt of the expected refraction, 98.8% within 2.0 dpt, whereas in the long-eye group 58.2% were within 1.0 dpt and 84.7% within 2.0 dpt. The results show that the SRKII formula performed credibly in average-length eyes; in the long eyes the ratio of large refractive deviations was greater than that of the other group.

Biometry↗
PubMed1992

A comparative rheological study on carbopol viscous solutions and, the evaluation of their suitability as the ophthalmic vehicles and artificial tears.

The rheological behaviours of different types of Carbopol (Carbopol 940, 934, 941 and 910) were investigated in the present work. Viscous solutions of these polymers were prepared in the range of concentration between 0.01-0.25% (w/w). 10% aqueous solution of sodium hydroxide was used for the neutralization procedure. Mannitol, sorbitol, sodium chloride and borate were tested to make the isotonic solutions. The viscosities of the solutions decreased dramatically with sodium chloride and sodium borate. Mannitol had no effect on the pH values of the solutions while sorbitol has showed a small effect. The solution prepared were sterilized by autoclaving and stored at 4 degrees C for 3 months. The pH value, viscosity and osmolality measurements were made after neutralization and sterilization, at the end of 1 and 2 weeks, 1, 2 and 3 months of storage. It could be concluded that four types of Carbopol are suitable for ophthalmic use. The aqueous vehicles of Carbopol 940 had an excellent appearance and clarity when compared with the other types of polymer.

Acrylic Resins↗
PubMed1991

Evaluation of the interfacial properties of a new potent antimicrobial surfactant C31G.

The surface activity of a new potent antimicrobial mixture (C31G) of alkyl betaines and alkyl amine oxides were evaluated in order to determine the relationship between its antimicrobial effectiveness and physical properties. Therefore the surface tension measurements were performed at different temperatures using an interfacial tensiometer. Critical micelle concentrations, interfacial and thermodynamic parameters of C31G were obtained from the surface tension data.

Anti-Infective Agents↗
PubMed1991

Formulation of Carbopol 940 ophthalmic vehicles, and in vitro evaluation of the influence of simulated lacrimal fluid on their physico-chemical properties.

Carbopol 940 ophthalmic vehicles were prepared in order to investigate the interaction between the simulated lacrimal fluid and the polymer, and to examine the influence of sodium fluorescein - a tracer for the fluorophotometric studies - on the physico-chemical properties of the polymer vehicles. Four kinds of vehicles containing mannitol (5%), sodium fluorescein (0.05%) and disodium edetate (0.01%) were formulated. Physicochemical properties of the preparations including pH, osmolality, surface tension and viscosity were measured after neutralization and sterilization, and also after 1 and 2 weeks, 1, 2 and 3 months of storage at 4 degrees C. The viscosity significantly decreased by adding sodium fluorescein and disodium edetate to Carbopol 940 vehicles. It was observed no significant effect of sterilization and storage on the viscosity, pH and osmolality. Significant change in the flow property of the vehicles was observed when the simulated lacrimal fluid was added. Three concentrations of Carbopol 940 vehicles (0.20%, 0.15% and 0.10%) both containing and not containing disodium edetate were proposed for in vivo evaluation.

Acrylic Resins↗
PubMed1990

Tear cholesterol levels in blepharitis.

The tear levels of cholesterol of 17 patients with chronic blepharitis and 17 healthy subjects were determined by the photometric method. The mean cholesterol level of the patients was determined to be 56.1 +/- 8.9 (SEM) mg/dl. No statistically significant difference between the tear cholesterol levels of the two groups could be detected.

Adult↗
PubMedDate not supplied

Role of the vitreous in age-related macular degeneration.

PURPOSE: To investigate the relationship between posterior vitreous detachment (PVD) and age-related macular degeneration (AMD). METHODS: The condition of the vitreous was examined by slit-lamp funduscopy and ultrasonography in 93 eyes of 50 patients with AMD (exudative or dry) and 100 eyes of 50 controls. RESULTS: There was complete PVD in 31 of the 93 eyes (33.3%) of 50 patients with AMD and the posterior vitreous was attached in 62 of these eyes (66.6%). In the control group, in 50 eyes (50%) of 50 subjects there was posterior vitreous detachment. The prevalence of PVD in eyes with macular degeneration was significantly lower (P < .05). There was no statistically significant difference between the exudative and the nonexudative groups in respect to PVD. CONCLUSIONS: PVD may have a protective role against the development of AMD. Chronic vitreomacular traction and/or continuous exposure to free radicals and cytokines may possibly be one of the causes of AMD in eyes with attached vitreous.

Aged↗
PubMedDate not supplied

Evaluation of retinoic acid ophthalmic emulsion in dry eye.

PURPOSE: An oil in water emulsion of 0.01% all-trans-retinoic acid (tretinoin) was prepared and clinically evaluated in dry eye patients. METHODS: The ophthalmic emulsion consisted of 10% of arachis oil and 90% of the hydrogel of Carbopol 940. To evaluate retinoic acid emulsion clinically, a placebo-controlled, open-labeled, randomized study was performed with 22 dry-eye patients. Symptoms were recorded before and after the treatments. The Schirmer I test, measurement of tear film break-up time (BUT), rose Bengal and fluorescein staining of cornea and conjunctiva, and mucus fern test were done. RESULTS: Retinoic acid did not improve the dryness, photophobia and foreign body sensation more than placebo. Schirmer test and BUT were significantly improved by retinoic acid treatment. Corneal and conjunctival epithelium maintained their characteristics during the use of retinoic acid, as indicated by rose Bengal and fluorescein staining. CONCLUSIONS: Ophthalmic emulsion of retinoic acid can be suggested as a promising approach for the treatment of dry eye.

Adult↗
PubMedDate not supplied

Surgical management of retinal detachment with choroidal coloboma.

PURPOSE: To verify the functional and anatomical results of retinal detachments related to choroidal coloboma. METHODS: Seven eyes with retinal detachment secondary to retinal breaks at the margin of or within a choroidal coloboma were analysed retrospectively. RESULTS: Scleral buckling was performed in five of the seven eyes; two needed additional pars plana vitrectomy (PPV) with internal tamponade using silicone oil to reattach the retina. In two eyes PPV with internal tamponade using silicone oil or gas was used as a primary procedure. All seven eyes were reattached. Five eyes (71.4%) showed improvement or had visual acuity of 20/400 or better after surgery, but two remained unchanged. CONCLUSIONS: Retinal detachment secondary to choroidal coloboma can be treated successfully by scleral buckling or PPV with internal tamponade.

Adult↗