The stress distribution of a primary molar tooth restored with stainless steel crown using different luting cements.

BACKGROUND: The aim of this study is to evaluate the stress distributions of a primary molar tooth restored with a stainless steel crown (SSC) using resin and glass ionomer luting cements by Finite Element Analysis (FEA). METHODS: Original DICOM data of a primary molar was used to create a 3D model. One model was prepared as a tooth model with SSC. A 30 µm cement layer was used in model. Two different luting cements were tested in the study: self-cure adhesive resin cement, and glass ionomer cement. Vertical and oblique loads of 330 N were applied to simulate maximum bite force and lateral forces in the occlusal contact areas of the models. Maximum von Mises stress values in the models were evaluated as MPa. RESULTS: The maximum von Mises stress value was observed in the force application and general occlusal contact areas for all models. The maximum von Mises stress values were higher in the tooth model with SSC using self-cure adhesive resin cement (478.09 MPa and 214.62 MPa) than in the tooth model with SSC using glass ionomer cement (220.06 MPa and 198.72 MPa) in both vertical and oblique loading, respectively. CONCLUSIONS: Depending on the magnitude of the bite force on the SSC, fracture of the luting cement materials could occur if the stress exceeds the endurance limit of the luting cement. Cementation with glass ionomer cement may help to reduce stress levels in SSC restorations of primary molars in children.

Evaluation of the amount of residual monomer released from different flowable composite resins.

Today, resin materials are used in the restoration of permanent and deciduous teeth or as fissure sealants. The materials can contain different types of monomers (Bis-GMA, UDMA, TEGDMA). These monomers can be released into the oral cavity after polymerization. Residual monomers released from resin-containing restorative materials after polymerization have been reported to have negative effects on mechanical properties. The aim of our study is to evaluate the amount of residual monomers released after polymerization of different flowable composite resin materials using two different modes of LED light source. Composite disc samples (8 mm diameter/2 mm depth) prepared for each material group were polymerized using two different modes of the LED light device (Standard mode and extra power mode). HPLC (High Performance Liquid Chromatography) device was used to measure the amount of residual monomer release at 1 h, 1 day, 3 days and 7 days periods. Pairwise comparison of the differences between the materials was performed by Post-hoc test. For each residual monomer, the Kruskal Wallis test was used to analyze the difference between the materials in standard mode and the difference between the materials in extra power mode. According to the results of the study; Grandio flow flowable composite showed the highest release of TEGDMA and Bis-GMA while SDR® Flow flowable composite showed the lowest release of TEGDMA, Bis-GMA and UDMA. For all materials, the extra power mode resulted in more residual monomer release. TEGDMA and Bis-GMA release was detected in all tested flowable composites at all time periods.

Adaptation of the Chabot Emotional Differentiation Scale: Turkish version validity and reliability study.

BACKGROUND: The aim of the study was to adapt the Chabot Emotional Differentiation Scale (CED) for use in Turkey and to contribute to the Turkish literature by conducting a validity and reliability study on the scale. PARTICIPANTS AND PROCEDURE: The study sample consisted of 369 volunteers between 18 and 52 years of age: 279 females (75.6%) and 90 males (24.4%), selected by the convenience sampling method. The construct validity of the scale was first tested with exploratory factor analysis and subsequently with confirmatory factor analysis. The Depression Anxiety and Stress Scale (DASS-42) and the Differentiation of Self Inventory-Short Form (DSI-SF) were used to test the convergent validity of the scale. The reliability of the scale was calculated by internal consistency and test-retest methods. RESULTS: Exploratory and confirmatory factor analysis revealed that the scale has a single factor structure. In the Turkish version of the scale, the 14th item was removed from the scale due to its low factor loading. The Cronbach's α internal consistency coefficient of the scale was found to be .86 while the test-retest reliability coefficient was calculated as .76. CONCLUSIONS: The analysis indicates that the Turkish version of the Chabot Emotional Differentiation Scale constitutes a reliable and valid measurement tool for use with a sample in Turkey.

Predicting perceived stress and resilience: the role of differentiation of self.

BACKGROUND: Differentiation of self is a process that describes an individual's ability to act by separating emotions and thoughts at the internal level as well as the ability to be activated by maintaining the self in intense relationships through the establishment of a balance between autonomy and closeness at the level of interpersonal relations. The aim of this study was to determine the role of the differentiation of self - which is one of the basic concepts of the Bowen family systems theory - in predicting perceived stress and resilience. PARTICIPANTS AND PROCEDURE: The research study group consisted of 423 individuals who were selected from a Turkish sample using the convenience sampling method. The study data were collected using a demographic form, the Differentiation of Self Inventory-Revised (DSI-R), the Perceived Stress Scale (PSS), and the Brief Resilience Scale (BRS). RESULTS: The results indicate that as the level of differentiation increases, the perceived stress decreases, and resilience increases. Furthermore, differentiation of self is shown to predict 33% of the perceived stress level and 35.2% of the resilience level. CONCLUSIONS: This study found that differentiation of self predicts the levels of stress that individuals experience and their resilience in stressful situations. The presented findings are meant to serve as a guide for mental health professionals working on coping with anxiety and stress, and increasing resilience in structuring the psychotherapy process.

Relationship dynamics: the protective effect of relationship satisfaction and dependency on parents' mental health after having a preterm baby.

BACKGROUND: Having a premature infant who is hospitalized with the risk of death and potential health problems is a traumatic experience for many parents. The present study investigated the depression, anxiety, stress, and post-traumatic growth (PTG) experienced by couples after the premature birth of their babies in terms of their relationship dynamics. PARTICIPANTS AND PROCEDURE: The study was conducted on 209 individuals - 159 mothers (76.1%) and 50 fathers (23.9%) - who had premature babies born at or before 32 weeks of gestation. The participants completed the Relationship Assessment Scale, Emotional Dependency Scale, Post-Traumatic Growth Inventory, the Depression, Anxiety, and Stress Scale, and a sociodemographic form. For interpretation of the data, intervariable relationships were analyzed using the Pearson correlation coefficient, and the mediation models were analyzed by the regression-based bootstrapping technique using the PROCESS Macro. RESULTS: The relationship satisfaction and emotional dependency experienced by parents had a positive correlation with PTG following preterm birth. Relationship satisfaction was associated with lower levels of depression, anxiety, and stress. Emotional dependency was correlated with lower levels of depression and stress but not anxiety. For the mediating variables, it was found that depression and anxiety had a full mediating role between relationship satisfaction and PTG but stress did not. It was determined that depression had a partial mediating role between emotional dependency and PTG but anxiety and stress did not. CONCLUSIONS: The study findings revealed the importance of establishing family- and baby-centered neurodevelopmental neonatal intensive care units (NICUs). The results suggested that having healthcare professionals, primarily nurses and doctors, make observations about the relationship dynamics of parents during their stay at the NICU and guide parents to receive psychological support if they perceive weaknesses in the relationship - since such weaknesses predict possible risks of depression, anxiety and stress - would support the functionality of families. The findings are discussed, and future directions are suggested.

The effect of 1.5 T and 3 T magnetic resonance imaging on microleakage of amalgam restorations.

The aim of this article is to compare the effects of 1.5 T and 3 T MRI on microleakage of amalgam restorations. A total of 90 extracted molar teeth were used in this study. Amalgam was used to restore standard Class V preparations (5 × 3 × 2 mm). Following the restoration, the teeth were divided into three groups according to magnetic resonance imaging (MRI) protocol (Group I: Control, Group II: 1.5 T MRI, and Group III: 3 T MRI). A total of 6,000 thermal cycles at 5°C-55°C were applied on all samples. Microleakage values were measured in millimeters using the ImageJ program. Microleakage values were higher in the gingival region compared to the occlusal region in all groups and the differences were statistically significant (p < .05). Microleakage values were not statistically different among the groups in the occlusal region (p > .05), while there were statistically significant differences among the groups with respect to microleakage values in the gingival region (p < .01). The highest mean microleakage amount in the gingival region was measured in Group III (1.192 ± 0.941 mm). This was followed by Group II (0.519 ± 0.813 mm) and Group I (0.347 ± 0.726 mm), respectively. Within the limitations of this in vitro study, we observed that higher microleakage values in amalgam restored teeth in which were exposed to MRI procedure. We also found that the teeth exposed to the stronger magnetic field showed higher microleakage amount.

Thermal conductivity of different colored compomers.

BACKGROUND: Compomers are mostly used in primary dentition. The thermal conductivity properties of traditional or colored compomers have not been investigated in detail so far. The aim of this in vitro study was to assess and compare the thermal conductivities of traditional and colored compomers. METHOD: Two sets of compomers - namely, Twinky Star (available in berry, lemon, green, silver, blue, pink, gold and orange shades) and Dyract Extra (available in B1, A3 and A2 shades) - were included in this study. All of the traditional and colored compomers were applied to standard molds and polymerized according to the manufacturers' instructions. Three samples were prepared from each compomer. Measurements were conducted using a heat conduction test setup, and the coefficient of heat conductivity was calculated for each material. The heat conductivity coefficients were statistically analyzed using Kruskal-Wallis and Duncan tests. Uncertainty analysis was also performed on the calculated coefficients of heat conductivity. RESULTS: Statistically significant differences were found (p<0.05) between the thermal conductivity properties of the traditional and colored compomers examined. Among all of the tested compomers, the silver shade compomer exhibited the highest coefficient of heat conductivity (p<0.05), while the berry shade exhibited the lowest coefficient (p<0.05). Uncertainty analyses revealed that 6 out of 11 samples showed significant differences. CONCLUSIONS: The silver shade compomer should be avoided in deep cavities. The material properties could be improved for colored compomers.

Is More Cortical Bone Decortication Effective on Guided Bone Augmentation?

This study aims to evaluate the possible effect of more cortical bone decortication (CBD) on guided bone augmentation. A total of 16 New Zealand rabbits and 32 titanium domes were used. No cortical bone decortication was applied to the control group and in the study groups, the cortical bones were decorticated with a round burr (Group A: 1 hole with bleeding, Group B: 5 holes with bleeding, Group C: a thin layer of compact bone was completely removed with no bleeding). Then 2 titanium domes were placed on the calvarium of each rabbit with hydroxyapatite/beta-tricalcium phosphate. After 3 months, the animals were sacrificed and specimens were sent for histological and histomorphometric analysis. Histological and histomorphometric analysis showed that bone decortication with burr significantly increased new bone regeneration in all the experimental groups compared with the control group (P <0.05). No statistically significant difference was determined between the study groups. In conclusion, CBD, which has no negative impact on surgery, has a positive effect on guided bone augmentation. However, a greater amount of CBD does not have a greater effect.

Evaluation of salivary total oxidant-antioxidant status and DNA damage of children undergoing fixed orthodontic therapy.

OBJECTIVE: To determine the total oxidant status (TOS), total antioxidant status (TAS), and the 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels and their interrelationship in the saliva of children undergoing fixed orthodontic therapy. MATERIALS AND METHODS: Thirty children were randomly divided into three groups. The attachments were bonded to all of the teeth using three different orthodontic composites: Transbond XT, Kurasper F, and GrenGloo. The salivary levels of TOS, TAS, and 8-OHdG were determined three times, as follows: before treatment (T1) and at 1 month (T2) and 3 months (T3) following appliance placement. All data were statistically analyzed. RESULTS: There were no significant differences in TOS, TAS, and 8-OHdG within the same time periods among the three different orthodontic composites (P > .05). TAS in all composite groups decreased over time. These decreases were found to be significant for Kurasper F and GrenGloo at the T1-T3 and T2-T3 time periods (P < .05). In all composite groups 8-OHdG decreased between T1 and T2 (P < .05). However, 8-OHdG in all composite groups increased from T2 to T3. These differences in 8-OHdG were significant in Kurasper F and GrenGloo (P < .05). CONCLUSIONS: Fixed orthodontic appliances bonded with the tested composites did not increase the cytotoxicity markers in saliva.

Effects of Er:YAG laser on mineral content of sound dentin in primary teeth.

The aim of the present study was to evaluate the mineral content of sound dentin in primary teeth prepared using an Er:YAG laser at two different power settings. Thirty-six primary second molars were used in this study. Three dentin slabs were obtained from each tooth, and the slabs were randomly divided into three groups: Group A, control; Group B, Er:YAG laser at 3.5 W, 175 mJ, and 20 Hz, short pulse mode; and Group C, Er:YAG laser at 4 W, 200 mJ, and 20 Hz, medium-short pulse mode. One dentin slab per group was used to evaluate the dentinal morphology and surface roughness values using SEM and profilometer, respectively. Mineral content in the dentin slabs were calculated by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The data were analyzed by one-way analysis of variance and Tukey's HSD tests. No significant differences in Ca, K, Mg, Na, and P levels or Ca/P ratio were found among the groups (P > 0.05). SEM micrographs showed that surface irregularities increased with a higher power setting. The surface roughness after laser treatment in Group B and Group C was found to be similar, unlike Group A.

Evaluation of tooth-fragment reattachment: a clinical and laboratory study.

PURPOSE: To evaluate the restoration of fractured teeth by reattaching tooth fragment to its tooth remnant in a group of children and adolescents, and to compare the results with those of a laboratory study. MATERIALS AND METHODS: The clinical study was conducted on 43 fractured incisors: 22 uncomplicated crown fractures (Group A) and 21 complicated crown fractures (Group B). The 43 incisal fragments: 23 were kept dry for 47 h and 20 were kept wet for 24 h by the patients before they were reattached. The fragments were kept in 0.9% saline solution for 30 min before reattachment. The fragments in Group A were reattached using a dentin bonding agent, a flowable and a hybrid resin composite, whereas the fragments in Group B were reattached to the tooth remnant after a pulpotomy was performed. The laboratory study was conducted on 56 extracted incisors. Teeth were divided equally into four groups: Group I - Uncomplicated crown fracture + wet medium; Group II - Uncomplicated crown fracture + dry medium; Group III - Complicated crown fracture + wet medium, and Group IV - Complicated crown fracture + dry medium. The fragments were then reattached in a manner that was similar to that used in the clinical study. The restored teeth were then re-fractured. All data were analyzed statistically. RESULTS: In the clinical study, the restored teeth were followed up for 2 years. Neither the type of trauma nor the storage medium had any significant effect on the survival, color, and bond strength of the restored teeth when assessed in the clinical and laboratory study. The color disharmony that was encountered initially in restored teeth resolved significantly on its own accord within 12 months after reattachment of the fragment. CONCLUSION: Fragment reattachment can be used to treat fractured teeth successfully in children and adolescents.