Evaluation of the Shear Bond Strength of Immediate and Delayed Restorations of Various Calcium Silicate-Based Materials with Fiber-Reinforced Composite Resin Materials.

Due to significant tissue loss in teeth requiring pulp treatments, hermetic restoration of the remaining dental tissues is one of the most crucial factors in determining the treatment's success. The adhesion of composite resins to calcium silicate cements (CSCs) is considered challenging. Consequently, it is crucial to identify the optimal method for obtaining optimal adhesion. The aim of the present study is to evaluate the shear bond strength (SBS) values of immediate and delayed restorations with fiber-reinforced composites on powder-liquid, premixed, and resin-containing flowable CSCs. In the present study, the SBS values obtained after immediate (14 min) and delayed (7 days) restorations of three different CSCs (NeoMTA2, NeoPutty, and TheraCal PT) with three different resin composite materials (EverX FlowTM, EverX PosteriorTM, and Filtek Z550) were compared. The fracture types were evaluated using a stereomicroscope and SEM. TheraCal PT had the highest SBS values for both immediate and delayed restorations, and the comparison with other materials showed a statistically significant difference (p = 0.001). In contrast, there was no statistically significant difference between the SBS values of NeoMTA and NeoPutty (p > 0.05). In both immediate and delayed restorations, there was no statistically significant difference between nanohybrid and fiber-reinforced composites (p > 0.05). The simple use and strong bonding ability of TheraCal PT with composite resins may provide support for the idea that it is suitable for pulpal interventions. Nevertheless, due to the in vitro nature of this study, additional in vitro and clinical studies are required to investigate the material's physical, mechanical, and biological properties for use in clinical applications.

In Vitro Comparison of Surface Roughness, Flexural, and Microtensile Strength of Various Glass-Ionomer-Based Materials and a New Alkasite Restorative Material.

This study aims to evaluate the physical properties of Cention N and various glass-ionomer-based materials in vitro. The groups were obtained as follows: Group 1 (LC-Cent): light-cured Cention N; Group 2 (SC-Cent): self-cured Cention N; Group 3 (COMP): composite (3M Universal Restorative 200); Group 4 (DYRA): compomer (Dyract XP); Group 5 (LINER): Glass Liner; Group 6 (FUJI): FujiII LC Capsule; and Group 7 (NOVA): Nova Glass LC. For the microtensile bond strength (µTBS) test, 21 extracted human molar teeth were used. The enamel of the teeth was removed, and flat dentin surfaces were obtained. Materials were applied up to 3 mm, and sticks were obtained from the teeth. Additionally, specimens were prepared, and their flexural strength and surface roughness (Ra) were evaluated. Herein, data were recorded using SPSS 22.0, and the flexural strength, µTBS, and Ra were statistically analyzed. According to the surface roughness tests, the highest Ra values were observed in Group 6 (FUJI) (0.33 ± 0.1), whereas the lowest Ra values were observed in Group 2 (SC-Cent) (0.17 ± 0.04) (p < 0.05). The flexural strengths of the materials were compared, and the highest value was obtained in Group 2 (SC-Cent) (86.32 ± 15.37), whereas the lowest value was obtained in Group 5 (LINER) (41.75 ± 10.05) (p < 0.05). When the µTBS of materials to teeth was evaluated, the highest µTBS was observed in Group 3 (COMP) (16.50 ± 7.73) and Group 4 (DYRA) (16.36 ± 4.64), whereas the lowest µTBS was found in Group 7 (NOVA) (9.88 ± 1.87) (p < 0.05). According to the µTBS results of materials-to-materials bonding, both Group 2 (SC-Cent) and Group 1 (LC-Cent) made the best bonding with Group 3 (COMP) (p < 0.05). It can be concluded that self-cured Cention N had the highest flexural strength and lowest surface roughness of the seven materials tested. Although the bond strength was statistically lower than conventional composites and compomers, it was similar to resin-modified glass ionomer cements. Additionally, the best material-to-material bonding was found between self-cured Cention N and conventional composites.

Effects of Er:YAG and Er,Cr:YSGG laser irradiation and adhesive systems on microtensile bond strength of a self-adhering composite.

This study was aimed to evaluate the effects of Er:YAG and Er,Cr:YSGG laser irradiation and adhesive systems on the microtensile bond strength of Fusio Liquid Dentin (FLD) which is a self-adhering composite (SAC). Twenty-four freshly extracted human molar teeth were collected, and the enamel was removed from the occlusal surface to obtain a flat dentin surface. Twenty-four teeth were randomly divided into eight groups: Group 1: only Fusio Liquid Dentin (FLD) (Petron Clinical, Orange, California, USA) was applied to the dentin surface; Group 2: 37% Phosphoricacid (i-GEL, Medicinos Linija UAB, Lithuania) + FLD; Group 3: Single Bond Universal (SBU) (3 M ESPE, Germany) + FLD; Group 4: Adper Easy One (AEO) (3 M ESPE, Germany) + FLD; Group 5: Er:YAG laser + AEO + FLD; Group 6: Er:YAG laser + SBU + FLD; Group 7: Er,Cr:YSGG laser + AEO + FLD; and Group 8: Er,Cr:YSGG laser + SBU + FLD. After thermocycling, 1 × 1 mm2 sticks were used for the µTBS test (n = 10). Two sticks per group were used for SEM analysis. Fractured sample surfaces were evaluated using a stereomicroscope. Group 8 showed the highest µTBS value (13.70 MPa), whereas Group 1 showed the lowest µTBS value (5.60 MPa). There were no significant differences between Groups 2, 3, and 4 (P = 0.324), but Groups 5-8 showed statistically significant results that were higher than Groups 1-4 (P = 0.012). Adhesive failure mode was predominant followed by mixed failure. The evaluation of bonding of the FLD to dentin showed that the combined use of Er:YAG and Er,Cr:YSGG lasers with SBU and AEO on dentin surfaces improved the dentinal bond strength of the FLD.

Evaluation of the accuracy of electronic apex locators, cone-beam computed tomography, and radiovisiography in primary teeth: An in vitro study.

Electronic apex locators (EALs), cone-beam computed tomography (CBCT), and radiovisiography (RVG) claim to determine of working length (WL) in primary molar teeth. To evaluate the accuracy of WL determination by using three EALs, RVG, and CBCT imaging in extracted human primary molar teeth with/without root resorption. Twenty extracted primary molar teeth with resorption and 20 extracted primary molar teeth without resorption were used. After measuring actual lengths (AL) (Group 1), the electronic WL measurements were performed by using three different EALs [COXO C Smart-1 Pro (Group 2), iPex (Group 3), and Apex ID (Group 4)]. Two different image sets were obtained as follows: CBCT imaging (Group 5) and RVG (Group 6). AL measurements performed with an endodontic measuring ruler and compared with the EAL, CBCT, and RVG image measurements. For all groups, there were no significant differences between the teeth with resorption and without. There were no significant differences in measuring methods from AL and between the methods used (p > .05). When electronic and radiographic method were compared in different frequency ranges, there was no statistically significant difference (p > .05). This study showed that EALs, CBCT, and RVG have high accuracy in primary molar teeth both with resorption and without root resorption and can be used for determining WL.

Antibacterial efficacy and remineralization capacity of glycyrrhizic acid added casein phosphopeptide-amorphous calcium phosphate.

The aim was to evaluate remineralization capacity and antibacterial efficiency of Tooth Mousse and various amounts of glycyrrhizic acid added Tooth Mousse on primary tooth enamel. Three groups were formed; Group 1 (CPP-ACP), Group 2 (CPP-ACP + 5% glycyrrhizic acid), and Group 3 (CPP-ACP + 10% glycyrrhizic acid) in order to evaluate remineralization capacity. Enamel samples were immersed in demineralization solution and then remineralization agents were applied. Surface microhardness and SEM analyses were performed at the beginning, after demineralization and remineralization. For antibacterial tests, four groups were formed; Group 1, Group 2 and Group 3 and Group 4 (control). Biofilms were then exposed to 10% sucrose eight times per day for 7 days. After biofilm growth period, samples were treated with materials to evaluate antibacterial efficiency except control group. After application of materials, samples were incubated 2 more days at 37°C and at the end of this period, absorbance values of biofilms were determined and data were analyzed. An increase in microhardness values was Group 2 > Group 3 > Group 1, respectively, but there were no significant differences. After remineralization, microhardness values showed significant increases when compared to demineralized groups, but there was no significant difference. All groups showed decreased absorbance value of biofilm when compared with control group but they were insignificant. It was observed that both in Group 2 and Group 3, glycyrrhizic acid did not have a negative effect on remineralization and although they have an increase, it was insignificant. Although glycyrrhizic acid added CPP-ACP groups showed increased antibacterial activity, they were not statistically significant.

The effect of different chelating agents on the push-out bond strength of proroot mta and endosequence root repair material.

PURPOSE: This study aimed to evaluate the effects of 17% ethylenediaminetetraacetic acid (EDTA), 7% maleic acid (MA), and 10% citric acid (CA) on the push-out bond strength of ProRooT MTA and Endosequence Root Repair Material (ERRM) putty. MATERIALS AND METHODS: Eighty single-rooted extracted human teeth were instrumented to obtain a standardized immature teeth model. Based on the chelating agents tested, the specimens were randomly divided into three experimental groups: Group 1 (17% EDTA), Group 2 (7% MA), Group 3 (10% CA), and Group 4 (Positive Control) (n=20 for each group). Each group was further classified into two subgroups: Group A (ProRoot MTA) and Group B (Endosequence Root Repair Material (ERRM) putty) (n=10 for each subgroup). After irrigation and placement of cements, teeth were stored at 37°C and in 100% humidity for a week. A total of 240 dentine discs (three discs per teeth) were obtained and subjected to push-out assay. Data was analyzed using two-way analysis of variance and Tukey's post hoc t-test. RESULTS: Both types of chelating agent and calcium silicate-based cement were significantly associated with the push-out bond strength values. The push-out bond strength was significantly less for CA as compared to EDTA or MA. ERRM had higher bond strength values than ProRoot MTA (p<0.05). CONCLUSION: The use of chelating agents increased the push-out bond strength of CSC. Regardless of tested chelating agents, ERRM had higher bond strength values than ProRoot MTA.

Flexural strength and microhardness of anterior composites after accelerated aging.

BACKGROUND: This study aimed to evaluate the flexural strength and microhardness of three different anterior composites after 10 000 thermocycles. MATERIAL AND METHODS: The mechanical properties of a nano-fill composite (Filtek Ultimate Universal Restorative (FUR) (Enamel)), a nano-hybrid composite (Clearfil Majesty ES2 (ES2) (Enamel)), and a micro-hybrid composite (G Aenial Anterior (GAA)) were investigated in this study. For the microhardness test, 8-mm diameter and 2-mm thickness composite discs were used (n = 10), and for the flexural strength test, 25x2x2 mm bar-shaped specimens were prepared (n = 13). The specimens were tested at 24 h and after 10 000 thermocycles. Data were analyzed using two-way analysis of variance and the post-hoc Tukey test (p < .05). Correlations between hardness and flexural strength were calculated using Pearson's correlation analysis. RESULTS: There was a significant difference in the microhardness values of the materials (p < .05). FUR exhibited significantly higher microhardness than ES2 and GAA. However, the flexural strength of three composites was statistically similar at 24 h (p > .05). Pearson correlation analysis revealed that there was a negative relationship between the mean hardness and flexural strength values (correlation coefficient = -0.367, p = .043). After 10 000 thermocycles, microhardness values of each material and flexural strength of ES2 and GAA decreased significantly according to 24 h. CONCLUSIONS: The nano-fill composite FUR displayed significantly higher microhardness values. However, each resin composite was statistically similar for flexural strength values. Ten thousand thermocycles significantly affected microhardness and flexural strength. Key words:Flexural strength, microhardness, anterior composites.

Clinical evaluation of apex locator and radiography in primary teeth.

AIM: The aim of this in vivo study was to evaluate the accuracy and reliability of electronic apex locater and radiographic determination of root canal length in primary teeth. METHODOLOGY: A total of 32 human primary molar teeth (96 roots) were selected. After endodontic access preparation, root canals were irrigated with physiological saline solution. The access cavities were dried with cotton pellets and, the roots were dried with paper points before performing the electronic measurement. The root canal length measurements were first taken with an apex locater (EndoMaster), and then, a size ♯ 15 K-file was inserted into the root canal, and radiography was taken to determine the working length measurements. The measurement data were recorded and compared by one-way anova and Kruskal-Wallis tests. P < 0.05 was accepted for the significance. RESULTS: The mean values for radiography were 13.23 ± 1.92 mm and for EndoMaster were 13.08 ± 1.77 mm. The accuracy of EndoMaster was 80.2% in correct measurements ±1 mm (P < 0.001). CONCLUSION: The electronic apex locators could be useful in determining working length and thereby decreasing the need for radiographs and exposure to ionizing radiation in pediatric dental patients.

The effect of Er:YAG laser and different surface conditioning procedures on microtensile bond strength of the fissure sealant containing amorphous calcium phosphate after artificial aging.

The present study aimed to compare post-aging microtensile values of fissure sealant(FS) containing amorphous calcium phosphate(ACP) with or without bonding after various enamel-etching methods. The buccal enamel surfaces of teeth were prepared and divided into five main groups according to enamel etching (Group 1; acid-etching, Group 2; air-abrasion, Group 3; 2W, Group 4; 3W, and Group 5; 4W of Er:YAG laser). Each main group was subdivided as with(Subgroup B) or without(Subgroup A) a bonding system. We applied FS-containing ACP to etched enamel surfaces. All specimens were aged by Thermocycling and water bath. We then measured microtensile bond strengths and analyzed data with two-way ANOVA and Tukey's tests. We found a statistically significant difference between Group 1 and Group 2, between Subgroup B of Group 5 and Subgroups B of all other groups, and between Subgroups A and Subgroups B of all main groups (p<0.01). Er:YAG laser-etching may be an alternative enamel etching method to acid-etching for ACP-containing FS.

Morphological analysis of the resin-dentin interface in cavities prepared with Er,Cr:YSGG laser or bur in primary teeth.

OBJECTIVE: The purpose of this study was to analyze the resin-dentin interface in cavities prepared with laser or bur in primary teeth. BACKGROUND DATA: Erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser was expected to be an alternative cavity preparation method, enhancing surface alterations and producing morphological changes. METHODS: Twenty extracted primary molar teeth were divided to four groups according to one of four cavity preparation and pretreatment regimens: Er,Cr:YSGG laser (G1), Er,Cr:YSGG laser+acid-etching (G2), bur (G3), and bur+acid-etching (G4). After applying composite resin to the cavities, the teeth were sectioned. The resin-dentin interface was analyzed under scanning electron microscopy (SEM) and ion analysis was performed with SEM-energy-dispersive X-ray spectroscopy (EDX) after immersion in ammoniacal silver nitrate solution. RESULTS: In G1 and 2, the surfaces were wavy, and in G3 and 4, the surfaces were smooth. Microcracks were seen in some of the lased cavities. In G1 and 2, dentin tubules were exposed and there was lack of a smear layer. In G3, there were gaps and a smear layer in the resin-dentin interface, but no gaps or smear layer were observed in G4. In G2, the resin tags were increased, and some resin tags were broken in cavities, which were prepared with laser (G1 and 2). CONCLUSIONS: According to the results of this study, acid-etching was recommended after laser preparations, to have a better adhesion.

Nanoleakage in primary teeth prepared by laser irradiation or bur.

The aim of this in vitro study was to analyze hybrid layer and nanoleakage of composite resin restorations in cavities prepared by either Er,Cr:YSGG laser or bur, followed by acid etching in primary teeth. Ten extracted primary molar teeth were randomly allocated into two groups consisting of ten cavities according to surface treatment regimen: Er,Cr:YSGG laser + acid etching(group 1) and bur + acid etching(group 2). Restorations of all samples were completed. Then, teeth were sectioned and immersed to ammoniacal silver nitrate solution. After polishing, hybrid layer thicknesses were examined under scanning electron microscopy (SEM) and ion analysis was carried out with SEM/energy dispersive X-ray spectroscopy preparation in terms of nanoleakage. Hybrid layer thickness and the amount of silver ions were assessed for the acid-etched groups. The collected data were analyzed with independent sample t test and Spearman's rank correlation. In groups 1 and 2, the mean hybrid layer thicknesses were 4.25 ± 1.41 and 5.24 ± 1.07 µm and the silver ion percentages were 10.97 ± 13.81 and 22.79 ± 21.62 %, respectively. Although no significant correlation was observed between the increase of hybrid layer thickness and the amount of silver ions, more silver ions were observed in group 2 (p < 0.05). According to the results of this study, acid-etched cavities prepared with laser promoted better results when compared to the acid-etched cavities prepared with bur.

KTP laser on microleakage of compomer restorations in Class V restorations.

AIM: To evaluate the effects of pulsed KTP (potassium-titanyl-phosphate) laser on decrease of dentinal microleakage of compomer restorations in primary teeth. METHOD: Twenty four primary molars were selected for the study After Class V cavity preparations in buccal and lingual surfaces, teeth were divided into three groups: Group 1: Control, Group 2: 1 WKTP laser Group 3: 1.5 WKTP laser. Then cavities were restored with compomer and teeth were thermocycled to 500 cycles, isolated and immersed in 0.5% basic fuchsin for 24 hours. Teeth were rinsed, dried, and sectioned, and microleakage was assessed by dye penetration at the occlusal and gingival surface of the teeth with stereomicroscope (40X). The data were analyzed with Kruskal-Wallis, Mann-Whitney U and Wilcoxon tests. RESULTS: When the scores of microleakage at the gingival margins of the groups were compared, the differences among the groups were found to be statistically significant (p<0.05). At the occlusal margins of the groups, there were no statistical differences (p>0.05). Comparing the gingival and the occlusal margins in the each group, statistically significant differences existed in the Groups 1 and 3 (p<0.05). CONCLUSIONS: KTP laser is able to seal dentinal tubules and consequently reduce microleakage towards pulp in primary teeth.

Factors affecting the timing of teething in healthy Turkish infants: a prospective cohort study.

BACKGROUND: Teething is a developmental process and occurs over a broad chronological age range. OBJECTIVE: The objective of this study was to evaluate the effects of feeding pattern and growth parameters on teething time of healthy infants. METHODS: A total of 1200 term newborn infants followed up in Gazi University well-child clinic infants were evaluated, and their growth parameters, feeding patterns, and timing of the eruption of the first tooth were noted. The routine visit times of the clinic were chosen as the cut-off values for teeth eruption for logistic regression analysis for investigating factors that determine the timing of teeth eruption. RESULTS: Timing of the eruption of the first tooth ranged from 4 to 13 months. On the sixth month visit, 24.3%, and on the ninth month visit 84.5% of all infants had at least one tooth. Height-adjusted weight and height percentiles being less than 50, being fed by cow's milk or by formula in the first year, were independent factors negatively influencing teeth eruption by the sixth month, while all but height-adjusted weight percentiles being less than 50 had negative impact on tooth eruption by the ninth month. CONCLUSION: Growth parameters and feeding pattern may be determinants of the timing of teeth eruption in healthy infants.

Clinical evaluation of diagnodent in detection of occlusal caries in children.

The aim of this in vivo study was to evaluate the effectiveness of DIAGNOdent, visual and radiographic examination in detecting non-invasive diagnosis of occlusal caries in children. In this study, 92 untreated molars with sound occlusal surface or enamel and/or dentin caries were selected from 28 healthy patients, aged 7-17 years. All teeth were examined by two researchers using each of three diagnostic system (DIAGNOdent, visual, radiographic). Interpretation of the DIAGNOdent value and the radiolucency on the bitewing film were combined with the visual examination to decide where the teeth had to be opened. Depth of caries was recorded. Sensitivities and specificities were calculated for each diagnostic method using the biopsy scores as gold standard. Intra- and inter-examiner reproducibility for each method was assessed by calculating Cohen's kappa. The kappa value of inter-examiner reproducibilty was highest for visual examination (0.935), and lowest for DIAGNOdent measurements (0.698). Intra-examiner reproducibilty of DIAGNOdent mesurements was also good (0.745 and 0.665). Sensitivity and specificity for DIAGNOdent, visual examination and bitewing radiography were 0.86/0.80, 0.69/1.00 and 0.36/1.00, respectively. It was concluded that Diagnodent with a high sensitivity may be useful adjunct to visual examination with a high specificity in detecting occlusal caries.