Irradiance effects on the mechanical properties of universal hybrid and flowable hybrid resin composites.

OBJECTIVES: A potential problem with high-intensity lights might be failure of polymer chains to grow and cross-link in a desired fashion, thereby affecting the structure and properties of the polymers formed. The purpose of this study was to evaluate mechanical properties of resin composites polymerized using four different light-curing units. METHODS: A conventional quartz-tungsten-halogen (QTH) light, a soft-start light, an argon-ion laser, and a plasma-arc curing light were used to polymerize disk-shaped (9.0mm diameter x 1.0 mm high) and cylinder-shaped (4mm diameter x 8 mm high) specimens of a universal hybrid and a flowable hybrid composite. Biaxial flexure strength, fracture toughness, hardness, compressive strength, and diametral tensile strength were determined for each composite. RESULTS: The use of the plasma-arc curing light, a high-intensity light, resulted in significantly lower hardness for the universal hybrid composite compared with the hardness obtained using the conventional QTH and the soft-start units. Hardness was the only mechanical property that was adversely affected by the use of a high-intensity light. SIGNIFICANCE: High-intensity lights might affect some resin composite mechanical properties, but this effect cannot be generalized to all resin composites and all properties.     

Parietal bone as graft material for maxillary sinus floor elevation: structure and remodeling of the donor and of recipient sites

Particulate parietal bone is used for maxillary sinus floor elevation procedure prior to dental implant placement. However, data on internal structure of the parietal bone and on graft remodeling and incorporation in the host bone are limited. We determined the structure and remodeling activities of 24 parietal bone specimens sampled at time of sinus grafting (T1 samples), and the amount and turnover of bone formed at the recipient site at time of implant placement (T2 samples, obtained 10 months after T1 samples, on average). In T1 samples, the outer cortex was 1.16+/-0.45 mm thick, had a typical haversian structure, and showed a low level of remodeling. In the cancellous portion of the samples, trabecular bone volume represented 52.8+/-10.3%. Bone remodeling was more active in the cancellous portion than in the cortical portion, but few osteoblasts and osteoclasts were seen. T2 samples consisted solely of trabecular bone, which occupied 49.4+/-18.4% of total sample volume. The boundary between new bone and the recipient bed was not discernible. Remnants of the graft particles were embedded within new bone, and showed signs of intense resorption. Bone remodeling was highly active, as shown by the presence of numerous osteoclasts resorbing new bone, together with thick osteoid seams and large osteoblasts. A loose cotton-like mineralized material was frequently observed in the marrow spaces; this acellular and non-collagenous material was strongly stained by toluidine blue, suggesting a glycoprotein nature. This study offers insights into cortical and trabecular bone structure and shows the low-level remodeling activity of parietal bone. About 10 months after grafting, the grafted chips were incorporated in new bone and almost completely resorbed. This high turnover may be beneficial for implant placement.     

Itraconazole pulse therapy for onychomycosis and dermatomycoses: An overview

Background: Itraconazole is a broad-spectrum antifungal agent that has been used to treat dermatomycosis and onychomycosis using continuous therapy. More recently the drug has been used as pulse dosing. Objective: Our purpose was to review the studies in which itraconazole pulse therapy (PT) has been administered in the management of dermatomycoses. Results: For tinea pedis and manuum, the recommended dosage is itraconazole 200 mg twice daily for 1 week (n = 220). A clinical response and mycologic cure rate of 90% ± 4% and 76% ± 6%, respectively, has been obtained. For tinea corporis/cruris, itraconazole 200 mg/day for 1 week (n = 354) resulted in a clinical response and mycologic cure rate of 90% ± 4% and 77% ± 6%, respectively. When three pulses of itraconazole are used to treat toenail onychomycosis (n = 1389), the clinical cure rate, clinical response, and mycologic cure rate at follow-up 12 months after the start of therapy were 58% ± 10%, 82% ± 3%, and 77% ± 5%, respectively. With two pulses for onychomycosis of the fingernails, the clinical cure rate, clinical response, and mycologic cure rate at follow-up, 9 months after the start of therapy, were 78% ± 10%, 89% ± 6%, and 87% ± 8%, respectively. Conclusion: Itraconazole PT is effective and safe in the treatment of tinea pedis/manuum, tinea corporis/cruris, and onychomycosis. (J Am Acad Dermatol 1997;37:969-74.)     

Graft hypertrophy of matrix-based autologous chondrocyte implantation: a two-year follow-up study of NOVOCART 3D implantation in the knee

Purpose

Graft hypertrophy is a major complication in the treatment for localized cartilage defects with autologous chondrocyte implantation (ACI) using periosteal flap and its further development, Novocart (a matrix-based ACI procedure). The aim of the present study is to investigate individual criteria for the development of graft hypertrophy by NOVOCART 3D implantation of the knee in the post-operative course of 2 years.

Methods

Forty-one consecutive patients with 44 isolated cartilage defects of the knee were treated with NOVOCART 3D implants. Individual criteria and defect-associated criteria were collected. Follow-up MRIs were performed at 3, 6, 12 and 24 months. The NOVOCART 3D implants were measured and classified. The modified MOCART Score was used to evaluate quality and integration of the NOVOCART 3D implants in MRI.

Results

Graft hypertrophy was observed in a total of 11 patients at all post-operative time points. We were able to show that NOVOCART 3D implantation of cartilage defects after acute trauma and osteochondritis dissecans (OCD) led to a significantly increased proportion of graft hypertrophy. No other individual criteria (age, gender, BMI) or defect-associated criteria (concomitant surgery, second-line treatment, defect size, fixation technique) showed any influence on the development of graft hypertrophy. The modified MOCART Score results revealed a significant post-operative improvement within 2 years.

Conclusion

The aetiology of cartilage defects appears to have a relevant influence for the development of graft hypertrophy. Patients, who were treated with NOVOCART 3D implants after an acute event (acute trauma or OCD), are especially at risk for developing a graft hypertrophy in the post-operative course of two years.

Level of evidence

Case series, Level IV.     

Effect of Aerva lanata on cisplatin and gentamicin models of acute renal failure

The ethanol extract of the entire plant of Aerva lanata was studied for its nephroprotective activity in cisplatin- and gentamicin-induced acute renal injury in albino rats of either sex. In the curative regimen, the extract at dose levels of 75, 150 and 300 mg/kg showed dose-dependent reduction in the elevated blood urea and serum creatinine and normalized the histopathological changes in the curative regimen. In the gentamicin model the rats in the preventive regimen also showed good response to the ethanol extract at 300 mg/kg. The findings suggest that the ethanol extract of Aerva lanata possesses marked nephroprotective activity with minimal toxicity and could offer a promising role in the treatment of acute renal injury caused by nephrotoxins like cisplatin and gentamicin.     

Oxidized low-density lipoproteins in cord blood from neonates with intra-uterine growth restriction

Objective

We verified whether oxidative stress indices (oxidized low-density lipoproteins and malondialdehyde) and inflammatory biomarkers (circulating C-reactive protein, interleukin-6, tumour necrosis factor-α, serum amyloid A and soluble intercellular vascular cell adhesion molecule) are increased in the umbilical vein of placental insufficiency induced intra-uterine growth restricted neonates.

Study design

The prospective cohort study, involving 3 tertiary care centers, consists of 200 consecutively recruited pregnant women carrying twins. We chose the twin pregnancy model because both fetuses share the same maternal environment, thereby avoiding potential confounding factors when comparing oxidative stress and inflammation biomarkers. We analysed only twin pairs with one with intra-uterine growth restriction (N = 38) defined as fetal growth < 10th percentile with abnormal Doppler of the umbilical artery. Blood samples were taken at birth from the umbilical vein. Intra-pair comparisons on the biomarkers were performed using the Student paired t-test.

Results

We observed increased cord blood levels of oxidized low-density lipoproteins, (2.394 ± .412 vs 1.296 ± .204, p = .003) but not of malondialdehyde in growth restricted neonates when compared to their normal counterparts. Although indices of inflammation tended to be increased in cord blood from growth restricted newborns, the difference did not reach statistical significance.

Conclusion

In the twin model, intra-uterine growth restriction is associated with low-density lipoprotein oxidation without apparent dysregulation of inflammation biomarkers.

Condensation

Increased oxidized low-density lipoproteins are observed in growth restricted twins compared to their co-twins with normal growth at birth.