Peek dental implants coated with boron-doped nano-hydroxyapatites: Investigation of in-vitro osteogenic activity.

BACKGROUND: PEEK is a high-performance thermoplastic that has many potential uses in orthopaedics and dentistry, and it has been shown to be a substitute for titanium (Ti) implants. However, PEEK is an inherently inert material, and that characteristic limits its cellular adhesion and bone integration. The aim of this study is to determine a suitable surface modification method for increasing the osteogenic potential of polyetheretherketone (PEEK) implants used in periodontal applications. METHODS: In this work, a nanostructured porous surface is created on PEEK material by sulfonation, in sulfuric acid at room temperature for 20 min, and thus SPEEK samples were obtained. Then, PEEK and SPEEK samples were coated with boron (B) doped hydroxyapatite (HAp) nanoparticles (B-nHAp) precipitated from concentrated synthetic body fluid (10xSBF) by a microwave-assisted method conducted at 600 W. In vitro cell culture studies were carried out with periodontal ligament cells (PDL) on the samples. Osteogenic differentiation of PDL cells on PEEK, SPEEK and SPEEK-B-nHAp was evaluated using ALP activity assay, hydroxyproline assay, and RT-qPCR. RESULTS: In vitro cell culture studies disclosed improved adhesion and proliferation of PDL cells on the SPEEK and B-nHAp coated SPEEK surfaces (SPEEK-B-nHAp). Results of these assays confirmed that treated PEEK surfaces, especially SPEEK-B-nHAp, significantly enhanced osteogenic differentiation of PDL cells in vitro compared with untreated PEEK surfaces. CONCLUSION: Here a simple, easy to-use, and efficient modification method based on the properties of boron is proposed for increasing osteogenic potential of PEEK implants.

Randomized Clinical Trial to Evaluate MTA Indirect Pulp Capping in Deep Caries Lesions After 24-Months.

OBJECTIVE: This clinical study aimed to assess the efficacies of mineral trioxide aggregate (MTA) and calcium hydroxide [Ca(OH)2] in the treatment of deep carious lesions by the direct complete caries removal technique. METHODS AND MATERIALS: A total of 100 permanent molar/premolar teeth were capped with either Ca(OH)2 (n=49) or MTA (n=51) and restored with composite resin in 73 patients. Periapical radiographs were acquired prior to the treatment as well as at six, 12, and 24 months posttreatment. Two calibrated examiners performed the clinical and radiographic assessment of the periapical pathology and pulpal symptoms. Intergroup comparisons of the observed values were performed using the Fisher exact test. Significance was predetermined at α = 0.05. RESULTS: The recall rates were 100% at six and 12 months posttreatment and 98.6% at 24 months posttreatment. Four teeth capped with Ca(OH)2 (two each at six and 12 months posttreatment) and two capped with MTA (one each at 12 and 24 months posttreatment) received endodontic emergency treatment because of symptoms of irreversible pulpitis, which were clinically and/or radiographically established. There were no significant differences in pulp vitality between the two pulp-capping agents at six, 12, or 24 months posttreatment (p=0.238, p=0.606, and p=0.427, respectively). CONCLUSIONS: Both pulp-capping materials were found to be clinically acceptable at 24 months posttreatment.

Clinical assessment of mineral trioxide aggregate in the treatment of deep carious lesions.

OBJECTIVE: This clinical study aimed to assess the effectiveness of mineral trioxide aggregate (MTA) and calcium hydroxide (Ca[OH]2) in the treatment of deep carious lesions using the direct complete caries excavation technique. SUBJECTS AND METHODS: Hundred permanent molars/premolars were capped either with Ca (OH)2 (n = 49) or MTA (n = 51) and restored with composite resin in 73 patients. Periapical radiographs were taken prior to the treatment, at 6 months and 12 months. Two calibrated examiners clinically and radiographically assessed the periapical pathology and pulpal symptoms. Inter-group comparisons of the observed values were analyzed using Fisher's exact test. Significance was predetermined at α = 0.05. RESULTS: Recall rates were 100% at 6 and 12 months. Four teeth capped with Ca(OH)2 (two each at the end of 6 and 12 months) and one tooth capped with MTA (at the end of 12 months) received endodontic emergency treatment because of symptoms of irreversible pulpitis that were clinically and/or radiographically established. There was no significant difference between the protection of the tooth vitality and pulp capping agents at 6 and 12 months (P = 0.238, P = 0.606, respectively). CONCLUSION: Both materials were clinically applicable at the end of 12 months.

Clinical Performance of Composite Restorations with Resin-modified Glass Ionomer Lining in Root Surface Carious Lesions.

OBJECTIVE: The purpose of this study was to evaluate the clinical performance of composite restorations in root surface carious lesions with or without resin-modified glass ionomer lining. METHODS AND MATERIALS: The sample consisted of 25 female and 14 male patients. A maximum of four lesions were included for each patient. After caries removal, the depth, length, and width of the cavity were measured. Lesions in the same patient were randomly divided into two groups, and the dentin surfaces were either lined with resin-modified glass ionomer liner (Glass Liner II) or left as they were. Self-etch adhesive (All Bond SE) was applied and cured for 20 seconds. All cavities were restored with nanohybrid anterior composite resin (Clearfil Majesty Esthetic). Two experienced clinicians evaluated the marginal adaptation (retention) rate, anatomic form, secondary caries, sensitivity, and marginal staining of restorations at the end of the first week and at six, 12, and 18 months posttreatment. The data were statistically analyzed using the Chi-square and two-way repeated measures tests. RESULTS: At the end of 18 months, a total of five lined and three unlined restorations were lost. There was no significant relationship between marginal adaptation and cavity lining at six, 12, and 18 months (p>0.05). Although marginal stainings of restorations were mostly localized, the total number of localized or generalized discolored restorations increased with time (p<0.001). There was a statistically significant relationship between marginal staining and smoking (p>0.05). There was no significant relationship between marginal staining and frequency of toothbrushing at six, 12, and 18 months (p=0.286, p=0.098, and p=0.408, respectively). CONCLUSION: Within the limitations of this study, both restorative applications were accepted as clinically appropriate.

Effects of isolation rooms on the prevalence of hospital acquired pneumonia in a respiratory ICU.

BACKGROUND: The incidence of hospital acquired pneumonia (HAP) varies according to the type of intensive care units (ICUs). AIM: The aims of this study were to determine the frequency of hospital acquired pneumonia (HAP) and the effect of isolation rooms on the frequency of pneumonia in the ICU. MATERIALS AND METHODS: The present investigation was carried out between January 2004 and July 2008. The ICU, which was 4-bed ward-type between January 2004 and February 2006 (1st period), was reconfigured as isolated rooms with only 2 beds each after March 2006 (2nd period). 153 and 379 patients were followed up in the ICU in the 1st and 2nd periods, respectively. Blood, sputum, and deep tracheal aspiration cultures were used for the isolation of the causative agents. RESULTS: No significant difference was detected between the general characteristics of patients. HAP developed in 101 patients (19%). The prevalence of HAP was 22.9% in the 1st period and 17.4% in the 2nd period. During the 1st and 2nd periods, the HAP infection densities were 22.2 and 16.1/1000 patient-days and the ventilator-associated pneumonia densities were 48.1 and 37.6/1000 ventilator-days, respectively. Eighty-six percent of HAP was ventilator-associated pneumonia (VAP). CONCLUSIONS: Isolation rooms in the ICU may be an effective strategy to control and decrease the rate of pneumonia in the ICU in addition to other preventive strategies.

Correlation between broth microdilution and disk diffusion methods for antifungal susceptibility testing of caspofungin, voriconazole, amphotericin B, itraconazole and fluconazole against Candida glabrata.

Candida glabrata is one of the most frequent organisms isolated from superficial and invasive fungal infections, after Candida albicans. This organism also exhibits intrinsically low susceptibility to azole antifungals and treatment often fails. The microdilution method is not very practical for use in routine susceptibility testing in the clinical laboratory, thus necessitating the use of other methods. In this study, we compared the in vitro activity of five antifungal agents in three different groups (echinocandin, polyene and azole) against 50 C. glabrata isolates by broth microdilution and disk diffusion methods recommended by Clinical Laboratory Standards Institute CLSI M27-A3 and CLSI M44-A, respectively. All the isolates were susceptible to amphotericin B (100%) and 98% of the isolates were susceptible to caspofungin by the broth microdilution method. Within the azole group drugs, voriconazole was the most active followed by fluconazole and itraconazole in vitro. The highest rate of resistance was obtained against itraconazole with a high number of isolates defined as susceptible-dose dependent or resistant. Although the disk diffusion method is easy to use in clinical laboratories, it shows very poor agreement with the reference method for fluconazole and itraconazole against C. glabrata (8% and 14%, respectively).

Effect of adhesive system type and root region on the push-out bond strength of glass-fibre posts to radicular dentine.

AIM: To compare interfacial strength in different thirds of the root canal amongst glass-fibre posts luted with four different adhesive luting agents. METHODOLOGY: A total of 44 extracted human single-rooted teeth were randomly divided in four groups and restored using glass-fibre posts and the following luting agents: All Bond SE/Duo-Link (ABSE), All Bond 3/Duo-Link (AB3), BisCem (BC), Clearfil ED primer II/Clearfil Esthetic Cement (CLF). One week after luting, the samples were thermocycled in water, and then embedded in acrylic resin. Three sections (cervical, middle and apical) of 2 mm thickness were prepared from each specimen, and the post in each section was subjected to a push-out test. One additional specimen for each group was prepared for scanning electron microscopy analysis and the bonding effectiveness to dentine was assessed. The data were analysed using the Kolmogorov-Smirnov test, two-way anova, one-way anova, and the Scheffe test (P < 0.05). RESULTS: The push-out bond strength values for BC and ABSE were not significantly different (P > 0.05), but both were significantly higher than the means for AB3 and CLF (P < 0.05) in the cervical and middle regions. The same trend was observed in the apical region, except for the AB3 and ABSE which were not significantly different (P > 0.05) from each other. There were significant differences in bond strength amongst root thirds, with a reduction in values from the cervical to apical third (P < 0.05). CONCLUSIONS: The use of BisCem and All Bond SE/Duo-Link combination with their simplified application procedures may be considered an alternative to the currently used systems for luting glass-fibre posts in root canal.

Rapid detection of Mycobacterium tuberculosis from sputum specimens using the FASTPlaqueTB test.

OBJECTIVES: To determine the performance of the FASTPlaqueTB test, based on bacteriophage amplification technology, by comparison with the BACTEC 460 TB culture system, the Löwenstein-Jensen (LJ) medium culture method and Ziehl-Neelsen (ZN) staining. METHODS: Of 400 sputum specimens studied in our laboratory, 19 were excluded due to contaminant growth. The FASTPlaqueTB test was performed according to the manufacturer's instructions. RESULTS: Only 42 of the 381 specimens examined were positive on at least one test: 30 were positive with ZN staining, 34 with LJ medium, 36 with the FASTPlaqueTB test and 39 with BACTEC 460 TB. The combination of BACTEC 460 TB and LJ medium culture was considered the gold standard. The sensitivity and specificity were 70.7% and 99.7% for ZN staining, 87.8% and 100% for the FASTPlaqueTB test, 82.9% and 100% for LJ, and 95.1% and 100% for BACTEC 460 TB. CONCLUSIONS: The FASTPlaqueTB test is useful in the rapid diagnosis of TB.

Spinal subdural Staphylococcus aureus abscess: case report and review of the literature.

Spinal subdural abscesses (SSA) are rare and to date only 57 cases have been reported. The exact incidence of the SSA is unknown. The most affected region is the thoraco-lumbar spine and the most common bacterial source is Staphylococcus aureus. The timing for magnetic resonance imaging is very important in these patients. Because early diagnosis and emergent treatment is vital to prevent the formation or progression of neurologic deficits.

A 3-year clinical evaluation of a gallium restorative alloy.

Several alternative materials have been suggested to take the place of amalgam, because of the environmental toxic effects of its mercury component. One such material is gallium-based alloy restoratives. The aim of this in vivo study was to compare the long-term clinical performance of a commercial gallium alloy with an admixed high copper amalgam alloy. For this purpose, 32 gallium and 32 amalgam restorations were placed in molar teeth in 14 human subjects. All the selected patients had at least two molar teeth that required restoration. In this way both restoratives were used in the same oral cavity. The restorations were examined at baseline, 6 months, 1, 2 and 3 years. At baseline, six teeth restored with gallium alloy showed post-operative sensitivity, whereas none of the amalgams were sensitive. At the end of 3 years, only a few amalgam restorations showed slight surface tarnish and marginal integrity loss. None of them needed replacement. Of the 32 gallium restorations placed, five had to be removed because of sensitivity, corrosion and tooth fracture. Also dramatic surface roughness and corrosion were noticed in 12 gallium restoration. According to the results of this clinical study, gallium-based restoratives should not be used before their physical properties are improved.

Effect of disinfectant application methods on the bond strength of composite to dentin.

The use of cavity disinfectants with composite resins has raised important questions regarding their potential adverse effects on bond strength. The purpose of this study was to evaluate the effect of cavity disinfection on the bond strength of composite resin to dentin. Buccal surfaces of 64 caries-free extracted human third molars were ground flat by diamond flat-end cylinder bur, polished with a series of silicon carbide abrasive papers and mounted in autopolymerizing acrylic resin. They were randomly distributed into four groups (of 16). In group 1 (control group), dentin surfaces were treated with 35% phosphoric acid, Permagen primer and Permagen bonding resin and no disinfectant was used. In group 2, cavity disinfectant was applied and acid etching, priming and bonding procedures were performed as in group 1. In group 3, cavity disinfectant was applied after acid etching. In group 4, cavity disinfectant was applied as in group 3, but it was rinsed off before priming and bonding procedures. Then a Teflon mould 3 mm thick and 4 mm in diameter was attached to the dentin surfaces, filled with composite resin and light polymerized. After the specimens had been thermocycled, shear bond strengths were determined. Application of the disinfectant before or after acid etching significantly reduced the shear bond strength of composite to dentin (P<0.05). Rinsing off the cavity disinfectant before the bonding procedure did not affect the bond strength (P>0.05). The use of cavity disinfectant with composite resin restorations can influence the dentin bond strength.

Two-year performance of glass-ceramic insert-resin composite restorations: clinical and scanning electron microscopic evaluation.

OBJECTIVE: This study evaluated the 2-year clinical performance of beta-quartz-resin composite restorations. METHOD AND MATERIALS: Twenty-two glass insert-resin composite restorations were placed. Restorations were placed in 6 molars, 12 premolars, and 4 incisors. After 2 years, clinical assessment of the restorations was made by three operators according to the US Public Health Service criteria. Scanning electron microscopic evaluations were made by replica technique. RESULTS: Nineteen restorations were graded Alfa and three restorations were graded Bravo for color match. Twenty-one restorations were graded Alfa and one restoration Charlie for proximal contact, marginal integrity, and anatomic form. None of the restorations showed marginal discoloration, tooth sensitivity, or caries. CONCLUSION: Glass-ceramic insert-resin composite restorations exhibited excellent performance after 2 years of clinical service.