Oral and Dental Laser Treatments for Children: Applications, Advantages and Considerations

It is of utmost importance to make children interested in and willing to use dental services in order to prevent and treat oral diseases. Therefore, pediatric dental practitioners need to learn new technologies such as lasers, in addition to basic principles. Lasers have opened new horizons in the treatment of both soft and hard oral tissue problems in children. The present article describes application of the most commonly used lasers and their advantages and considerations

Score Generalizability of Writing Assessment: the Effect of Rater’s Gender

The score reliability of language performance tests has attracted increasing interest. Classical Test Theory cannot examine multiple sources of measurement error. Generalizability theory extends Classical Test Theory to provide a practical framework to identify and estimate multiple factors contributing to the total variance of measurement. Generalizability theory by using analysis of variance divides variances into their corresponding sources, and finds their interactions. This study used generalizability theory as a theoretical framework to investigate the effect of raters’ gender on the assessment of EFL students’ writing. Thirty Iranian university students participated in the study. They were asked to write on an independent task and an integrated task. The essays were holistically scored by 14 raters. A rater training session was held prior to scoring the writing samples. The data were analyzed using GENOVA software program. The results indicated that the male raters’ scores were as reliable as those of the female raters for both writing tasks. Large rater variance component revealed the low score generalizability in case of using one rater. The implications of the results in the educational assessment are elaborated

Effect of PTEN Gene Mutations and Environmental Risk Factors on the Progression and Prognosis of Bladder Cancer.

Bladder cancer is the most frequent genitourinary malignancy in Iran. Environmental and genetic factors are the two factors linked with bladder cancer expansion. The aim of this study was to investigate the role of PTEN gene and environmental risk factors on the progression and prognosis of bladder cancer.We evaluated 55 tumor specimens and 66 bladder mucosa samples of non-cancerous patients between 2011 and 2013. All samples were analyzed for PTEN mutations using PCR and direct DNA sequencing methods. Demographic data collected, were analyzed using SPSS version 19.0 software and a P value of < 0.05 was considered statistically significant.Of the 55 patients examined, tumor stage was T1, T2 (T2a, T2b) in 34 (61.8%) and 21 (38.2%) and tumor grade was high, low in 34 (61.8%) and 21 (38.2%), respectively. No mutations in the PTEN gene were found in patients with bladder cancer and control. Among the risk factors studied, only the occupation and history of urinary tract stones, were significantly associated with bladder cancer (P valu

Molar Incisor Hypomineralization: A Study of Prevalence and Etiology in a Group of Iranian Children

Objective: The aim of this study was to investigate the prevalence of molar incisor hypomineralization (MIH) and its relationship with systemic conditions in a group of Iranian children. Methods: The study population comprised of 433 7-9 year olds, from four schools in Zahedan, Iran. Subjects were evaluated clinically by one examiner, and at a separate session, their mothers completed a coded medical history questionnaire. Hypo-mineralized molars and incisors were recorded based on DDE (developmental defects of enamel) index and DMFT (number of decayed, filled and missing teeth) was determined. Statistical analyses were performed using Chi-square and independent sample t-tests. Findings: Fifty-five (12.7%) children showed MIH. The overall mean number of affected teeth was 0.2. The mean value of DMFT in MIH children was greater than in normal children. Demarcated opacities were the most frequent (76%) enamel defect. Mother’s and child’s medical problems during prenatal, perinatal and post natal period were significantly remarkable in MIH children. Conclusion: The prevalence of MIH in a group of Iranian children was 12.7%. Prenatal, perinatal and post natal medical conditions were more prevalent in children affected by MIH

Assessment of nickel release from stainless steel crowns.

Adverse effects of dental materials, especially metals, have been an important issue in recent decades.The purpose of this study was to determine the amount of nickel released from stainless steel crowns in artificial saliva.In this in-vitro study, 270 stainless steel crowns were divided into five groups, each with nine subgroups. Each group (I to V) was comprised of four, five, six, seven and eight crowns, respectively. Each subgroup was placed in a polyethylene jar containing artificial saliva and held in an incubator at 37°C for four weeks. The amount of released nickel was determined on days 1, 7, 14, 21 and 28, using an atomic absorption spectrophotometer. Wilcoxon Signed-Rank and Kruskal-Wallis with Dunn's post hoc tests (SPSS software, v. 18) were used for statistical analysis at a significance level of 0.05.The mean level of nickel on day 1 was more than that of day 7; this difference was statistically significant for all groups (P < 0.05), except for group II (P = 0.086). Also, the mean difference of released nickel between the groups was significant on day 1 (P = 0.006) and was insignificant on day 7 (P = 0.620). The nickel levels were zero on days 14, 21, and 28.The amount of nickel was below the toxic level and did not exceed the dietary intake

The effect of using different rinsing angles on the micro-tensile bond strength of the sealant to the etched enamel

Background: Attempts to enhance bond strength of the sealant have been among the most important sides of dental research. Aim: The purpose of the present study was to evaluate the effect of using different rinsing angles on the micro-tensile bond strength of the sealant to the etched enamel. Settings and Design: Experimental study. Materials and Methods: Sixty first-premolars were randomly assigned to six groups based on the rinsing angle applied (15°, 30°, 45°, 60°, 75°, and 90°). Following etching and rinsing, a 4-mm height build up of sealant material was created. Bonded specimens were sectioned into sticks (1 Χ 1 mm), which were subjected to micro-tensile bond strength, testing at a cross-head speed of 0.5 mm/min. Statistical Analysis Used: The data were analyzed by Kolmogorov-Smirnov and post-hoc Tukey test. Results: The tensile bond strength in specimens rinsed at 90° were statistically higher compared to those rinsed at 15° and 30° (P < 0.05), and increasing the angle from 15° to 90° was correlated with a reduction in the number of specimens with adhesive failures. Conclusions: Rinsing the conditioned enamel surface at 90° may improve the bond strength and retention of the sealant

The Effect of Calcium Pre-Rinse on Salivary Fluoride After 900 ppm Fluoride Mouthwash: A Randomized Clinical Trial

Objective: Calcium fluoride deposit during fluoride application. Uptake and retention of fluoride by saliva depends generally on the concentration of calcium. In this study, the ef-fect of calcium pre-rinse on salivary fluoride concentration after a 900 ppm fluoride mouthwash was investigated.Materials and Methods: This cross-over double-blind randomized clinical trial was con-ducted in a girls' dormitory in Zahedan University of Medical Sciences, southeast Iran. In this study, 42 female dental students were chosen using simple randomization. During the first phase, 21 subjects (group A) used fluoride rinse (F regimen) and the remaining (group B) used calcium pre-rinse followed immediately by fluoride rinse (Ca + F regi-men). In the second phase, participants rinsed using the mouthwashes not previously used. Prior to each phase prophylaxis was performed and no fluoridated product was used dur-ing a two-week interval between the phases. Salivary samples were taken immediately be-fore (baseline), 1 and 12 hours after rinsing. The salivary fluoride concentration was de-termined using fluoride sensitive electrode. Repeated measures ANOVA was used for sta-tistical analysis and the significance level was set at P<0.05.Results: There was significant difference between fluoride concentrations at different time points (P< 0.001). Significant differences were observed when the different time points of two regimens were examined. In contrast to this, the baseline before using F regimen and the baseline before using Ca + F regimen did not show any significance (P= 0.070).Conclusion: Pre-rinsing with calcium before fluoride is recommended because of signifi-cant increases in salivary fluoride concentration

Comparative evaluation of antibacterial effect of Malva sylvestris L. extract and chlorohexidine on Streptococcus mutans in vitro study

Background: Identifying the best species of medicinal plants and extracting effective substances can be effective in preventing oral and dental illness. The Malva sylvestris L. is among these plants. Malva sylvestris L. belongs to Malvaceae family from which A great deal of (Malvone A: 2-methyl-3-methoxy-5,6-di- hydroxy-1,4-naphthoquinone) anthocyanin and important natural pigments have been extracted. Anthocyanins and other substances of Malva sylvestris own antibacterial properties. Antibacterial properties of Malva sylvestris were investigated on the bacterial species. The purpose of this study was to investigate the antibacterial effects of the Malva sylvestris L. extract on the Streptococcus mutans and compare it with the effect of chlorohexidine (0.12%). Methods: This experimental study was carried out at the Shahed University of Medical Sciences, Tehran, Iran in the field of microbiology in January 2016 to September 2016. Methanolic aqueous extract of Malva sylvestris L. was prepared by decoction extraction method. The presence of polyphenol trepnoid, saponine, anthocyanins compounds in the extract was approved by high performance thin layer chromatography. Chromatographic and spectral fingerprint analysis plays an important role in the quality control of complex herbal medicines. The antimicrobial effect of the Malva sylvestris L. on the growth of Streptococcus mutans was evaluated. Results: Extract at different concentrations (16.8-4.2 mg/ml) had an antibacterial effect and compared with commonly used chlorohexidine in dentistry. The non-growth halo against Streptococcus mutans showed an average of 1.66 mm. The minimum inhibitory concentration against Streptococcus was 2 mg/ml. The presence of polyphenols, troponides of saponin, was characterized by high performance thin-layer chromatography (HPTLC). Conclusion: However, antibiotics play an important role in human health, with the increasing occurrence of bacterial resistance against available antibiotics. The results of this study showed that the aqueous-methanolic extract of the Malva sylvestris L. plant has antimicrobial activity affecting Streptococcus mutans. The flowers extract also showed high antibacterial effects against some human pathogen bacteria strains. This property of polyphenolic compounds of the plant, identified by fingerprint analysis, was less susceptible to chlorohexidine than gold standard