35 research outputs found
Long-Term Bonding Efficacy of CAD/CAM Hybrid Restorative Materials and Universal Adhesives.
OBJECTIVES
In-office and lab milled prostheses are the staple for indirect restorations. It is therefore critical to determine their long-term bonding durability.
METHODS
CAD/ CAM blocks of two classes of restorative materials: 1) a nano-ceramic reinforced polymer matrix (NCPM) and, 2) a polymer-infiltrated ceramic network (PICN) were bonded using four different universal adhesives (UA) and silane systems. A lithium disilicate glassceramic (LDS) was used as a reference. The blocks were bisected and bonded with different UA/resin-cement pairs. Bonded blocks were then cut into 1.0x1.0x12.0 mm bar specimens for microtensile bond testing. Half the bars were subjected to bond strength testing immediately and the other half after aging by 50,000 thermal cycles between 5°C and 55°C. ANOVA and post-hoc tests were used to compare mean bond strength among groups.
RESULTS
NCPM presented consistently high bond strength regardless of bonding techniques, while the bond strength of PICN and LDS were lower when bonded with UA relative to traditional silanes. The more hydrophilic UA produced higher bond strengths.
DISCUSSION
Glass-ceramics exhibited lower bond strength with UA than the conventional etch-rinse-silane techniques. However, UAs preserved bonding interface in the long-term.
SIGNIFICANCE
NCPM displayed superior bond strength relative to PICN and LDS regardless of the type of adhesives and bonding techniques
Psychiatric comorbidities in a community sample of women with fibromyalgia
Abstract Prior studies of careseeking fibromyalgia (FM) patients often report that they have an elevated risk of psychiatric disorders, but biased sampling may distort true risk. The current investigation utilizes state-of-the-art diagnostic procedures for both FM and psychiatric disorders to estimate prevalence rates of FM and the comorbidity of FM and specific psychiatric disorders in a diverse community sample of women. Participants were screened by telephone for FM and MDD, by randomly selecting telephone numbers from a list of households with women in the NY/NJ metropolitan area. Eligible women were invited to complete physical examinations for FM and clinician-administered psychiatric interviews. Data were weighted to adjust for sampling procedures and population demographics. The estimated overall prevalence of FM among women in the NY/NJ metropolitan area was 3.7% (95% CI = 3.2, 4.4), with higher rates among racial minorities. Although risk of current MDD was nearly 3-fold higher in community women with than without FM, the groups had similar risk of lifetime MDD. Risk of lifetime anxiety disorders, particularly obsessive compulsive disorder and post-traumatic stress disorder, was approximately 5-fold higher among women with FM. Overall, this study found a community prevalence for FM among women that replicates prior North American studies, and revealed that FM may be even more prevalent among racial minority women. These community-based data also indicate that the relationship between MDD and FM may be more complicated than previously thought, and call for an increased focus on anxiety disorders in FM.
Central poststroke pain and Wallenberg's lateral medullary infarction : Frequency, character, and determinants in 63 patients
Central poststroke pain (CPSP) is an infrequently recognized complication of lateral medullary infarction (LMI). We determined the frequency, nature and predictors of this complication in 63 patients with LMI. The hypothesis tested was that the degree of clinical sensory loss and extent of infarction seen on MRI, both graded by a predetermined scoring scale, would be predictive of CPSP. We also performed quantitative sensory testing (QST) of thermal and pressure sensation thresholds in a subgroup of 19 patients (nine with CPSP and 10 without) to analyze in detail the spinothalamic and trigeminothalamic systems mediating these modalities from both sides of the face and body. We analyzed these results for specific markers of CPSP.Results: CPSP developed in 25% (16/63) of the patients, all within 6 months. This was constant and severe with frequent allodynia, but responded in all cases to amitriptyline and recurred promptly on attempted weaning. CPSP affected the ipsilateral peri-orbital region most commonly, either alone or in combination with the contralateral limbs. Ipsilateral neurotrophic facial ulceration developed in two cases. CPSP correlated significantly (Fisher's exact test, p < 0.0002) with the degree of clinical sensory loss but not with the size of infarction seen on MRI (Fisher's exact test, p = 0.7). QST revealed a highly specific (100%) and sensitive(89%) finding for CPSP-thresholds from the cheek contralateral to the LMI were normal in eight of nine cases with CPSP and abnormal in all of the 10 cases without CPSP. Abnormalities in the face contralateral to the infarct are referable to the crossed trigeminothalamic tract in the reticular formation medial to the infarcted lateral medulla. We conclude that this argues for the theory that central pain is caused by denervation sensitivity of the "paleo"-reticulothalamic connections due to a selective"neo"-spinothalamic lesion.</jats:p
The impact of a modified cutting flute implant design on osseointegration
Information concerning the effects of the implant cutting flute design on initial stability and its influence on osseointegration in vivo is limited. This study evaluated the early effects of implants with a specific cutting flute design placed in the sheep mandible. Forty-eight dental implants with two different macrogeometries (24 with a specific cutting flute design Blossom group; 24 with a self-tapping design - DT group) were inserted into the mandibular bodies of six sheep; the maximum insertion torque was recorded. Samples were retrieved and processed for histomorphometric analysis after 3 and 6 weeks. The mean insertion torque was lower for Blossom implants (P < 0.001). No differences in histomorphometric results were observed between the groups. At 3 weeks, P = 0.58 for bone-to-implant contact (BIC) and P = 0.52 for bone area fraction occupied (BAFO); at 6 weeks, P = 0.55 for BIC and P = 0.45 for BAFO. While no histomorphometric differences were observed, ground sections showed different healing patterns between the implants, with better peri-implant bone organization around those with the specific cutting flute design (Blossom group). Implants with the modified cutting flute design had a significantly reduced insertion torque compared to the DT implants with a traditional cutting thread, and resulted in a different healing pattern
Surface Characterisation And Bonding Of Y-tzp Following Non-thermal Plasma Treatment.
(1) To chemically characterise Y-TZP surface via X-ray photoelectron spectroscopy (XPS) and evaluate the surface energy levels (SE) after non-thermal plasma (NTP). (2) To test the microtensile bond strength (MTBS) of Y-TZP bonded to cured composite disks, after a combination of different surface conditioning methods. Twenty-four Y-TZP discs (13.5mm×4mm) were obtained from the manufacturer and composite resin (Z-100) discs with similar dimensions were prepared. All discs were polished to 600 grit and divided into 8 groups (n=3 disks each), four control (non-NTP treated) and four experimental (NTP treated for 10s) groups. All groups received one of the four following treatments prior to cementation with Rely×Unicem cement: sand-blasting (SB), a Clearfil ceramic primer (MDP), sand-blasting+MDP (SBMDP), or baseline (B), no treatment. SE readings and surface roughness parameters were statistically analysed (ANOVA, Tukey's, p<0.05). Mixed model and paired samples t-tests were used to compare groups on MTBS. XPS showed increase in O and decrease in C elements after NTP. The polar component increased for BP (42.20mN/m) and SBP (43.77mN/m). MTBS values for groups BP (21.3MPa), SBP (31MPa), MDPP (30.1MPa) and SBMDPP (32.3MPa) were significantly higher in specimens treated with NTP than their untreated counterparts B (9.1MPa), SB (14.4MPa), MDP (17.8MPa) and SBMDP (24.1MPa). (1) Increase of O and decrease of C led to higher surface energy levels dictated by the polar component after NTP; (2) NTP application increased MTBS values of Y-TZP surfaces.4151-
Nuclear F-actin cytology in oral dysplasia and oral squamous cell carcinoma
Oral cavity cancer has a low 5-y survival rate, but outcomes improve when the disease is detected early. Cytology is a less invasive method to assess oral potentially malignant disorders relative to the gold-standard scalpel biopsy and histopathology. In this report, we aimed to determine the utility of cytological signatures, including nuclear F-actin cell phenotypes, for classifying the entire spectrum of oral epithelial dysplasia and oral squamous cell carcinoma. We enrolled subjects with oral potentially malignant disorders, subjects with previously diagnosed malignant lesions, and healthy volunteers without lesions and obtained brush cytology specimens and matched scalpel biopsies from 486 subjects. Histopathological assessment of the scalpel biopsy specimens classified lesions into 6 categories. Brush cytology specimens were analyzed by machine learning classifiers trained to identify relevant cytological features. Multimodal diagnostic models were developed using cytology results, lesion characteristics, and risk factors. Squamous cells with nuclear F-actin staining were associated with early disease (i.e., lower proportions in benign lesions than in more severe lesions), whereas small round parabasal-like cells and leukocytes were associated with late disease (i.e., higher proportions in severe dysplasia and carcinoma than in less severe lesions). Lesions with the impression of oral lichen planus were unlikely to be either dysplastic or malignant. Cytological features substantially improved upon lesion appearance and risk factors in predicting squamous cell carcinoma. Diagnostic models accurately discriminated early and late disease with AUCs (95% CI) of 0.82 (0.77 to 0.87) and 0.93 (0.88 to 0.97), respectively. The cytological features identified here have the potential to improve screening and surveillance of the entire spectrum of oral potentially malignant disorders in multiple care settings