PurposeContrast, sharpness, enhancement, and density can be changed in digital systems. The important question is to what extent the changes in these variables affect the accuracy of caries detection.Materials and MethodsForty eight extracted human posterior teeth with healthy or proximal caries surfaces were imaged using a photostimulable phosphor (PSP) sensor. All original images were processed using a six-step method: (1) applying "Sharpening 2" and "Noise Reduction" processing options to the original images; (2) applying the "Magnification 1:3" option to the image obtained in the first step; (3) enhancing the original images by using the "Diagonal/" option; (4) reviewing the changes brought about by the third step of image processing and then, applying "Magnification 1:3"; (5) applying "Sharpening UM" to the original images; and (6) analyzing the changes brought about by the fifth step of image processing, and finally, applying "Magnification 1:3." Three observers evaluated the images. The tooth sections were evaluated histologically as the gold standard. The diagnostic accuracy of the observers was compared using a chi-squared test.ResultsThe accuracy levels irrespective of the image processing method ranged from weak (18.8%) to intermediate (54.2%), but the highest accuracy was achieved at the sixth image processing step. The overall diagnostic accuracy level showed a statistically significant difference (p=0.0001).ConclusionThis study shows that the application of "Sharpening UM" along with the "Magnification 1:3" processing option improved the diagnostic accuracy and the observer agreement more effectively than the other processing procedures.

Introduction: Mouthwashes which prevent and control caries and periodontal diseases are commonly used even without professional prescription. Long-term use of mouthwashes may cause softening of restorative composites and lowering the longevity of restoration. The aim of this study was evaluation of surface hardness value of a microhybride composite (Filtek Z250) after 12 hours immersion in three kinds of alcohol-free mouthwashes. Materials and Methods: 72 Cylinderical specimens of a microhybride composite 5mm wide were prepared, using drinking straw as a mold. Specimens were light-cured continuously for 40 seconds on each side with Elipar(3M,ESPE) curing light. The specimens were immersed in 50ml of distilled water for12 hours. After that, all of them were finished with silicone carbide papers under constant water as coolant. The specimens were divided into 4 groups, each with 18 samples, the first group immersed in Colgate plax , the second in Crest (pro-health for me) , group3 in OraCare and group4 in water as the control group for 12 hours, which is equivalent to 1 year of daily mouthwash use at 2 minutes per day. Hardness measurement was taken by Vickers hardness tester with 1 kilogram load and 10 seconds loading time. Result: Statistical analysis according to t-test and One-Way ANOVA test showed that there was no significant difference in surface hardness value of composite after 12 hours immersion between groups of mouthwashes and water(P value=0.353) Conclusion: Based on the present study, alcohol-free mouthwashes didn't affect the surface hardness of Filtek(Z250) composite.

Purpose The use of micro-computed tomography (micro-CT) scans in biomedical and dental research is growing rapidly. This study aimed to explore the scientific literature on approaches and applications of micro-CT in restorative dentistry. Materials and Methods An electronic search of publications from January 2009 to March 2021 was conducted using ScienceDirect, PubMed, and Google Scholar. The search included only English-language articles. Therefore, only studies that addressed recent advances and the potential uses of micro-CT in restorative and preventive dentistry were selected. Results Micro-CT is a tool that enables 3-dimensional imaging on a small scale with very high resolution. In this method, there is no need for sample preparation or slicing. Therefore, it is possible to examine the internal structure of tissue and the internal adaptation of materials to surfaces without destroying them. Due to these advantages, micro-CT has been recommended as a standard imaging tool in dental research for many applications such as tissue engineering, endodontics, restorative dentistry, and research on the mineral density of hard tissues and bone growth. However, the high costs of micro-CT, the time necessary for scanning and reconstruction, computer expertise requirements, and the enormous volume of information are drawbacks. Conclusion The potential of micro-CT as an emerging, accurate, non-destructive approach is clear, and the valuable research findings reported in the literature provide an impetus for researchers to perform future studies focusing on employing this method in dental research.

Introduction: Retention of fiber reinforced composite posts depends on the bond strength between post and cement, and cement and root dentin. The aim of this study is to evaluate the bond strength of one type of fiber post to radicular dentin with different adhesive cements. Materials and Methods: Crowns of 44 cariesfree, human premolar were removed 2 mm below the CEJ and the roots were endodontically treated, then prepared for post cementation. The samples were randomly divided into 4 groups, group 1: Breeze (self-adhesive), group 2: ED Primer II/Panavia F2 (self-etch), group 3: Prime & Bond NT dual-cure /All-Cem (etch & rinse), and group 4: GC Fuji Plus. After post cementation and composite filling of coronal portion(as manufacturers,s instruction) and thermocycling, each specimen was cut into 2 mm thickness from the middle third of the root and the push-out bond strength test was performed and failure modes were recorded. Data were analyzed employing ANOVA and post hoc tests (P value< 0.05). Results: Group 4 showed significantly the highest bond strength (12.88±3.44 MPa), while group 1 showed significantly l ower bond strength than the other groups (5.25±2.98MPa). Also a statistically significant difference was observed between groups 2 and 3 with group 4.(P value<0.021) Conclusion: Retention of fiber post was affected by cement type. The results also indicated that in GC Fuji Plus the chemical interactions between the cement and hydroxyapatite may be important for root dentin bonding. Breeze without any pretreatment procedure cannot obtain the acceptable bond strength.