Effects of different dentin thicknesses and air cooling on pulpal temperature rise during laser welding

The neodymium/yttrium–aluminum–garnet (Nd/YAG) laser has been suggested to repair broken prostheses in the mouth. This study investigated the effects of different dentin thicknesses and air cooling on pulpal temperature rise during laser welding. Three intact human maxillary molars were prepared for full-veneer crown. For each tooth, dentin thicknesses in mesiobuccal cusp was 2, 3, or 4 mm. Twenty dies were duplicated from each of the prepared teeth. For metal copings with 0.5-mm thickness, wax patterns were prepared with dip wax technique directly onto each of dies. All patterns were sprued and invested. The castings were made using a nickel–chromium alloy (Nicromed Premium, Neodontics). A hole with 0.5-mm diameter was prepared on the mesiobuccal cusp of each crown. The Nd/YAG laser (9.85 W; 1 Hz repetition rate; fluence, 1.230 J/cm²; Fidelis Plus 3, Fotona) was used for welding with or without air cooling (n?=?10). The temperature rise was measured in pulpal chamber with a J-type thermocouple wire that was connected to a data logger. Differences between start and highest temperature reading were taken, and temperature rise values were compared using two-way analysis of variance and Tukey’s honestly significant difference tests (α?=?.05). Pulpal temperature rise varied significantly depending on the dentin thickness and air cooling (p?<?0.05). The non-air cooling group induced significantly the highest temperature increases. There were no significant differences between 2- and 3-mm dentin thicknesses groups (p?>?0.05); however, pulpal temperature rise was the lowest for 4-mm dentin thickness group (p?<?0.05). The highest values of thermal increase were found in the pulp chamber (6.8°C) when no air cooling was used in 2-mm dentin thickness group. Laser welding on base metal castings with Nd/YAG laser can be applied with air cooling to avoid temperature rises known to adversely affect pulpal health when dentin thickness is 2 or 3 mm.     

Ocular manifestations in phakomatosis pigmentovascularis: Current concepts on pathogenesis,diagnosis, and management

Phakomatosis pigmentovascularis is a rare congenital multisystemic disease with variable manifestations where a vascular malformation of the skin is associated with a pigmentary nevus. Ocular involvement includes glaucoma, choroidal hemangioma, and pigmentary alterations that predispose to uveal melanoma. Diagnosis is made on clinical grounds, although recent advances in molecular genetics have better clarified the etiopathogenesis of the condition. The advent of improved imaging techniques such as enhanced depth imaging spectral domain optical coherence tomography has provided new insight into the ocular alterations, enabling better follow-up of patients. We review the ophthalmic manifestations of the disease with an update on etiopathogenesis and current management strategies.     

Evaluation of the effect of unilateral late blindness on the retina,optic nerve and choroid parameters in the sighted eye

International Ophthalmology - To investigate whether unilateral late blindness alters the peripapillary retinal nerve fiber layer (RNFL), ganglion cell complex (GCC), central macular thickness...     

Steroid Responsiveness of Children with Idiopathic Nephrotic Syndrome in Southeastern Region of Turkey

Background. Our aim was to determine the prognostic factors effective in the response to steroid treatment and relapse frequency. Patients and Methods. In this study, we evaluated 84 children with idiopathic nephrotic syndrome followed-up from 1997–2002. The variables were analyzed with respect to medical history, physical examination, laboratory findings, response to treatment, and factors associated with remissions and relapses. Our study group consisted of 62 children with minimal change nephrotic syndrome (MCNS), 11 children with focal segmental glomerulosclerosis (FSGS), and 11 children with diffuse mesangial proliferation (DMP). Results. According to response to steroids; 57.1% were steroid-sensitive with infrequent relapses, 22.6% were steroid-dependent with frequent relapses, and 20.2% were steroid-non-responders. Significantly high non-responder ratios to steroids were found in children with initial hypertension and hematuria (p < 0.05). Although patients older than six years were found to be associated with steroid non-response (p < 0.05), the number of relapses were found to be increased with an increasing number of infections (p < 0.05). The time period for the first relapse was found to be statistically correlated with relapse numbers of the first 6 (p = 0.001) and 12 (p = 0.01) months. Conclusion. The time span between initial presentation and remission and the number of infections were significant for relapse frequency. The existence of hematuria and hypertension and age greater than 6 years at initial presentation were associated with steroid non-responsiveness. The likelihood of developing resistance to the treatment should be emphasized early to the parents of patients bearing these risk factors, and hence the possible disappointment in the family should be prevented.     

Ethnic differences in the soft tissue profiles of Turkish and European-American young adults with normal occlusions and well-balanced faces

The aim of this study was to evaluate soft tissue differences between Turkish and North American adults by comparing two sample populations with ideal occlusion and well-balanced faces. Lateral cephalometric radiographs of 117 Anatolian Turkish adults (65 female and 52 male, mean age: 23.9 ± 2.8 years) were compared with a sample of 116 adults of European-American ancestry (64 female and 52 male, mean age: 25.0 ± 6.8 years). The cephalometric analyses of Holdaway, Epker, and Legan and Burstone were performed using Dolphin Image Software 9.0. Thirty-two measurements (27 linear and 5 angular) were analysed. For statistical evaluation, independent samples t-tests were performed. Distinct differences were found between the two samples in facial convexity, upper lip position and length, lower lip position, chin prominence, and chin thickness. Vertical proportional findings were similar between groups. Ethnic differences were found between Turkish and North American adults in the soft tissue profile. It is appropriate to consider these differences during routine diagnosis and treatment planning of a Turkish patient or an American patient of European ancestry.     

Laser biostimulation of wound healing: bioimpedance measurements support histology

Laser biostimulation in medicine has become widespread supporting the idea of therapeutic effects of photobiomodulation in biological tissues. The aim of this study was to investigate the biostimulation effect of laser irradiation on healing of cutaneous skin wounds, in vivo, by means of bioimpedance measurements and histological examinations. Cutaneous skin wounds on rats were subjected to 635 nm diode laser irradiations at two energy densities of 1 and 3 J/cm² separately. Changes in the electrical properties of the wound sites were examined with multi-frequency electrical impedance measurements performed on the 3rd, 7th, 10th, and 14th days following the wounding. Tissue samples were both morphologically and histologically examined to determine the relationship between electrical properties and structure of tissues during healing. Laser irradiations of both energy densities stimulated the wound healing process. In particular, laser irradiation of lower energy density had more evidence especially for the first days of healing process. On the 7th day of healing, 3 J/cm² laser-irradiated tissues had significantly smaller wound areas compared to non-irradiated wounds (p?<?0.05). The electrical impedance results supported the idea of laser biostimulation on healing of cutaneous skin wounds. Thus, bioimpedance measurements may be considered as a non-invasive supplementary method for following the healing process of laser-irradiated tissues.     

The effects of low-level laser irradiation on breast tumor in mice and the expression of Let-7a,miR-155, miR-21, miR125, and miR376b

Low-level laser therapy (LLLT) is a form of photon therapy which can be a non-invasive therapeutic procedure in cancer therapy using low-intensity light in the range of 450–800 nm. One of the main functional features of laser therapy is the photobiostimulation effects of low-level lasers on various biological systems including altering DNA synthesis and modifying gene expression, and stopping cellular proliferation. This study investigated the effects of LLLT on mice mammary tumor and the expression of Let-7a, miR155, miR21, miR125, and miR376b in the plasma and tumor samples. Sixteen mice were equally divided into four groups including control, and blue, green, and red lasers at wavelengths of 405, 532, and 632 nm, respectively. Weber Medical Applied Laser irradiation was carried out with a low power of 1–3 mW and a series of 10 treatments at three times a week after tumor establishment. Tumor volume was weekly measured by a digital vernier caliper, and qRT-PCR assays were performed to accomplish the study. Depending on the number of groups and the p value of the Kolmogorov-Smirnov test of normality, a t test, a one-way ANOVA, or a non-parametric test was used for data analyses, and p?<?0.05 was considered to be statistically significant. The average tumor volume was significantly less in the treated blue group than the control group on at days 21, 28, and 35 after cancerous cell injection. Our data also showed an increase of Let-7a and miR125a expression and a decrease of miR155, miR21, and miR376b expression after LLLT with the blue laser both the plasma and tumor samples compared to other groups. It seems that the non-invasive nature of laser bio-stimulation can make LLLT an attractive alternative therapeutic tool.