Journal of Dentomaxillofacil Radiology, Pathology and Surgery
Volume:12 Issue: 1, Winter 2023

The present in vitro study compared the effects of three whitening toothpastes on the surface roughness of a nanohybrid composite resin.

Fifty-five disk-shaped composite resin samples (Opallis) were produced and divided into five groups based on the brushing with toothpastes (n=11): 1. Whitening toothpaste containing blue-covarine (White Now, Signal); 2. Whitening toothpaste containing hydrogen peroxide (Optic White, Colgate); 3. Whitening toothpaste containing abrasive agents (Opalescence, Ultradent); 4. Conventional toothpaste (Max Fresh, Colgate); 5. Control (storage in distilled water). Brushing in all test groups was carried out using a brush testing machine. Changes in surface roughness (Ra) and the surface morphology of composite resin were evaluated using profilometry and electron microscopy, respectively. The data were analyzed with paired-samples t-test, Wilcoxon, Kruskal-Wallis, and Mann-Whitney tests. (α=0.05).

Brushing with different kinds of toothpaste increased the Ra of the composite resin compared to the baseline (p<0.05). There were significant differences in Ra between the groups (P<0.001). The Optic White toothpaste group exhibited higher surface roughness than the conventional toothpaste group (Max Fresh) (P<0.001), with no significant differences from the White Now and Opalescence groups (P=0.065 and P=0.523, respectively).

Hydrogen peroxide-containing whitening toothpastes caused the greatest changes in surface roughness and morphology of the nanohybrid composite resin compared to the conventional toothpaste.

The incremental filling technique in traditional resin composites results in reduced polymerization shrinkage. However, many products have recently been introduced as low-shrinkage resin composites that make the bulk-filling of cavities possible.

Three identical dental models from a premolar tooth were made using a CADCAM digital scanner in the solid work software environment. MOD cavities were designed and filled by Tetric EvoCeram® Bulk Fill, GC KALORE™, and 3M ESPE Filtek P60 (control group) resin composites. Incremental and bulk-fill techniques were used for Tetric EvoCeram® Bulk Fill while GC KALORE™, and 3M ESPE Filtek P60 resin composites were used with incremental technique in Ansys 16 simulation software environment. Stress distribution and cuspal deflection rate were analyzed in Ansys 16 software by Kruskal–Wallis and Mann-Whitney U tests.

The mean stress intensity for Tetric EvoCeram® Bulk Fill in the bulk-fill technique was more than the incremental technique. Cuspal deflection rate and stress distribution among the resin composites, GC KALORE™, Tetric EvoCeram® Bulk Fill, and 3M ESPE Filtek P60 were in ascending order, respectively. Stress distribution was more uniform in the incremental technique.

The GC KALORE™ resin composite had the least stress distribution and cuspal deflection rate.

The purpose of this review article was to summarize the scientific literature investigating all invitro methods that can evaluate both marginal and internal adaptation of direct and indirect restorations. An electronic search of publications from 2000 to March 2022 was made using ScienceDirect, PubMed, and Google Scholar databases. The search included only English-language articles. Therefore, only studies that addressed techniques to measure marginal and internal adaptation in different restorations were selected. Five laboratory methods with different capabilities have been introduced to check the adaptation of dental restorations, including sectioning, Silicon Replica Technique (SRT), Micro-CT, OCT, and triple scan method. In addition, there are factors that may contribute to differences between different methods in measuring adaptation, including 2D, 3D, and absolute adaptation, cost, and feasibility of performing in the oral cavity. SRT and traditional sectioning have the advantage of being simple and inexpensive procedures. Micro-CT, OCT, and triple scan method are costly procedures that necessitate specialized equipment and analysis software which enable both 2D and 3D analysis. Another crucial aspect of the assessment techniques to be applied in clinical trials is the capability to conduct an examination in the oral cavity. Sectioning, OCT, and Micro-CT cannot be used to make assessments in the oral cavity, however SRT and triple scan method can. The search for an ideal and standardized device to measure the adaptation of direct and indirect restorations in dentistry is still needed.

The influences of natural forces and functional stimulation on form were first reported by Roux in 1883 as result of studies performed on the tail, fins of dolphins. Roux described the characteristics of functional stimuli as they build, mold, remold, and preserve the tissues . His working hypothesis became the biomechanical background of both general orthopedics and functional jaw orthopedics. The clinical aspects of the Roux hypothesis had already been applied by Robin, treating children with his “monobloc” as indicated in cases with glossoptosis(1). The forces employed in orthodontic and orthopedic procedures include both tensile and shearing forces. Tensile forces cause stress and strain in functional therapy. They also alter the stomatognathic muscle balance. Both external (primary) and internal (secondary) forces can be observed in each force application(1).

Periodontitis is an inflammatory-infectious disease of tooth-supporting structures that results in the progressive destruction of the periodontal ligament and alveolar bone due to an imbalance between the host defense and microorganisms. Subgingival microbiota has a significant role in the initiation and progression of periodontitis, affecting the innate and acquired immune responses by the infiltration of immune cells such as monocytes and polymorphonuclear cells that are abundant under inflammatory conditions. The immune cells induce the release of proinflammatory cytokines that lead to the destruction of periodontal connective tissue and the alveolar bone. Cytokines activate hepatocytes to produce acute phase proteins as a component of the nonspecific response. These proteins are a group of proteins that increase (positive type) and decrease (negative type) under inflammatory conditions. This response is called the acute phase response (APR) that occurs after the initiation of a systemic inflammatory reaction. Nonsurgical periodontal therapy is the first stage of treatment for periodontitis. Its aim is to eliminate etiologic agents and decrease inflammation. The aim of this review article was to evaluate the effect of periodontitis as an inflammatory condition and its treatment on the concentrations of negative acute phase proteins.

Higher emotional intelligence can lead to higher moral sensitivity and ultimately improve the quality of students’ performance. The present study was designed to investigate the relationship between emotional intelligence and moral skills of dental students of Alborz University of Medical Sciences in 2020.

The present study is a cross-sectional study, descriptive and analytical, which was conducted in the academic year of 2019-2020 among the students of the third year and above of the dental field at the Faculty of Dentistry of Alborz University of Medical Sciences. To collect data, Bar-On Emotional Intelligence Questionnaire and Moral Skills Questionnaire were used. After coding, the data were analyzed by SPSS version 24 software. For this purpose, the obtained information was analyzed using linear and multiple regression models and Pearson’s correlation coefficient

In the present study, 30 people including 20(67%) women and 10(33%) men were studied. The results of the present study showed that there is no significant difference between the variables of emotional intelligence and moral skills. But there was a strong positive relationship between emotional intelligence and overall values of moral skills (P=0.000). Also, in moral skills, there was a significant positive  relationship between emotional intelligence and moral integrity (P=0.019) and moral courage (P=0.035).

The results of this study showed that students with higher emotional intelligence have higher level of moral skills. It is suggested to include workshops related to emotional intelligence in the educational courses of students, especially dental students, to increase this ability in students.