Efficiency of Silver Staining in Differential Diagnosis of Adenoid Cystic Carcinoma from Polymorphous Low-Grade Adenocarcinoma

Objectives The aim of this study is find a practical and easy way to histologically differentiate between two malignant tumors namely Adenoid Cystic Carcinoma (ACC) and Polymorphous Low-grade Adeno Carcinoma (PLGA) silver nitrate staining.Methods In this cross-sectional study, 30 parrafin-embedded blocks of ACC and nine paraffin-embedded blocks of PLGA with the most acceptable standards were selected and stained with silver nitrate. Then the number and quality (size and pattern) of the stained spots in five random microscopic fields at 100× magnification (at least 100 cells) were evaluated. T-test was used to compare the number of dots between the two tumors while the quality of dots was compared with the Mann-Whitney U test.Results The mean silver stainable nucleolus organizer region (AgNOR) count was 3/45 for ACC and 2/45 for PLGA. Significant differences were observed in the number of dots between ACC and PLGA (p=0.004), but there was no statistically significant difference between the two tumors in terms of quality of dots.Conclusion AgNOR count can be useful as an available method in confirm the diagnosis of ACC and differentiate it from PLGA

Effect of Different Enamel Preparation Methods on Microleakage of Fissure Sealant: An In Vitro Study

Objective: Lack of a dental material with optimal adhesion and sealability is an important challenge in modern dentistry leading to marginal leakage. There are controversies on the necessity of enamel preparation in pit and fissure sealant therapy and its effect on decreasing the microleakage; therefore, the present in vitro study aimed to assess the amount of microleakage with and without enamel preparation.Methods: In this experimental study, 30 sound premolars assigned suitable for sealant application, were chosen and randomly divided into two groups. Sealant was applied to all teeth with the same conventional technique. In group A, fissure sealant was applied without enamel preparation while in group B, sealant was applied after fissurotomy with bur. The teeth were thermocycled and microleakage was measured using silver nitrate as leakage tracer. The teeth were then cut into three bucco-lingual sections and examined under a stereomicroscope with 32× magnification. The amount of dye penetration into the sealant was recorded in microns and the degree of microleakage was classified into four degrees of 0, 1, 2 and 3. T-test was applied for the comparison of data between the two groups.Results: In total,20% of specimens in group B (fissurotomy) had degree 1 and 80% had degree 0microleakage and no specimen had degrees 2 and 3 microleakage, while in group A (no preparation), 20% had degree 1, 33.3% had degree 2 and 46.7% had degree 3microleakage. No specimen had degree 0 microleakage. Therefore, placement of sealant with enamel preparation significantly decreased microleakage (p<0.001).Conclusion: In view of the findings of this investigation, it seems that enamel preparation reduces marginal leakage in pit and fissure sealant therapy

Microscopic Evaluation of Cleaning Efficiency of Three Different Nickel-Titanium Rotary Instruments

INTRODUCTION: This study compared the cleaning efficiency of Mtwo, Race and Medin Nickel-Titanium (NiTi) rotary instruments. MATERIALS AND METHODS: Sixty mandibular molar mesial roots were selected with angle curvatures between 25-35 degrees and divided into three groups; each containing 20 teeth. Canals were prepared with the rotary files and irrigated with 2.5% NaOCl solution after each instrument. Total of 5mL of normal saline was used as the final rinse; subsequently the canals were dried with paper points. The amount of debris and smear layer in three parts of the root canal walls was evaluated using SEM and the data were analyzed by using the Kruskal-Wallis test and the Mann-Whitney U test. RESULTS: The results for remnant debris in the coronal part of root canals were similar, whereas in the middle third, Mtwo instruments achieved significantly better results compared to Race and Medin instruments. In the apical third of the root canals more debris was created by Race instruments. CONCLUSION: Overall, Mtwo instruments had greater success in producing clean canals

Oral alterations among children with congenital zika virus syndrome: A systematic review and meta-analysis

Background and aim: the aim of present study was evaluating the oral alterations in children with congenital Zika syndrome -associated microcephaly compared to the group of children without this problem. Method: all international databases, PubMed, Scopus, Science Direct, ISI, and Embase were examined, searching between 2015 to March 2023 based on keywords related to the objectives of the study. Stata/MP v.17 software was used to conduct the meta-analysis. Result: After reviewing the abstracts of 177 articles, 21 articles were selected for full text review, of which 5 articles were included in the meta-analysis. Odds ratio of delayed tooth eruption between children with congenital Zika syndrome group and control group was 1.79 (OR, 1.79 95% CI 1.33, 2.25; p<0.001). Children with congenital Zika syndrome -associated microcephaly, compared to healthy children, had 2.15 (OR, 2.15 95% CI 1.62, 2.67; p<0.001) times chance of palate alteration. Conclusion: chance of delay in deciduous dental eruption, difficulty in lip sealing, palate alteration and ankyloglossia in children with CZS-associated microcephaly was significantly more than the control group