Impact of repeated preheating of bulk-fill resin composite on postoperative hypersensitivity; a randomized controlled clinical trial.

BACKGROUND: This clinical study was conducted aiming to evaluate the impact of repeated preheating of bulk-fill resin composite on postoperative hypersensitivity. METHODS: A total of 105 eligible, consenting adults were recruited. Patients had posterior teeth suffering from proximal decay with no signs of irreversible pulpitis. Patients were prepared for Class II restorations and restored with bulk-fill resin composite. Patients were randomized into three groups of 35 patients according to the number of preheating cycles for the resin composite syringe used; group I: no preheating; control group at room temperature, group II: Resin composite preheated once, and group III: Resin composite preheated ten cycles. Patients were assessed for postoperative dentin hypersensitivity using the visual analogue scale (VAS) at three-time intervals: day one, one week and by the end of one month after restorative treatment. Statistical analysis was performed; ANOVA with a single factor was used to test for significance at a p value ≤ 0.05. For nonparametric data, the Kruskal‒Wallis test was used to compare the three testing groups. Friedman's test was used to study the changes within each group. Dunn's test was used for pairwise comparisons when the Kruskal‒Wallis test or Friedman's test was significant. RESULTS: The scores of the three groups through the three time intervals were almost zero except for the first day where VAS scores were recorded with maximum score of 3 for groups I and II. Groups II and III; there was no statistically significant change in hypersensitivity scores by time with P-values 0.135 and 0.368, respectively. However, for group I there was a significant difference from VAS score recorded on first day and the two following time intervals. CONCLUSION: The repeated preheating cycles of bulk-fill resin composite prior to curing had no adverse effect on the patients regarding postoperative dentin hypersensitivity. This information could be of utmost significance, as the same resin composite syringe can undergo numerous preheating cycles clinically before it is completely consumed with the advantage of improvement on the handling properties. TRIAL REGISTRATION: The protocol of the current study was registered at www. CLINICALTRIALS: gov , with the identification number NCT05289479 on 21/03/2022. All procedures involving human participants were performed in accordance with the ethical standards of the Research Ethics Committee of the Faculty of Dentistry, Minia University, Egypt, under the approval number 73/440 on 11/09/2020.

The clinical performance of dental resin composite repeatedly preheated: A randomized controlled clinical trial.

OBJECTIVES: To assess the clinical performance of class II restorations performed by repeatedly preheated resin composite "RC" at 68 °C up to ten times. METHODS: 105 patients were selected and randomized into three groups, each comprising 35 patients. Each patient was provided with a single class II Bulk-fill resin composite "BF-RC" posterior restoration based on the number of preheating cycles; group I (H0): The BF-RC was packed non-heated, group II (H1): BF-RC preheated once, and group III(H10): BF-RC preheated ten cycles. These restorations were evaluated at 1, 3,6, and 12 months, using the modified United States Public Health Service "USPHS". Statistical analysis was performed using Kruskal-Wallis test, Mann Whitney U test, and Friedmann test, where p = 0.05. RESULTS: All the 105 restorations did not suffer from any clinical situation that recommended replacement regarding retention, fracture, secondary caries, or anatomical form. Although all performed restorations did have Alpha and Bravo scores with good clinical performance, the non-preheated RC restorations"" suffered from relatively inferior clinical performance through the follow-up period regarding marginal adaptation, marginal discoloration, and color matching when compared to preheated groups. One and ten times of preheating conducted better clinical performance. CONCLUSIONS: After 12-months follow-up, although no restoration needed replacement or repair in the 3 tested groups, restorations with single and ten times of preheating aided in better clinical performance of RC restorations compared to the non-preheated restorations. Preheating of RC for 10 times could be used safely with good clinical performance of restorations. CLINICAL SIGNIFICANCE: By continually preheating RC syringe up to ten times, the dentist will not only benefit from the enhanced clinical performance and easiness of application but also will use preheated RC syringes without hesitation, relying on the absence of drawbacks related to multiple preheating cycles.

Dentinal Tubule Occluding Efficacy Of Er: YAG Laser And Universal Adhesive Loaded With Nano-Carbonated Apatite.

ER:YAG laser and experimental resin-based dental adhesive loaded with functionalized carbonated apatite filler were used in this study to evaluate the dentin interaction in terms of penetration and occlusion of the dentinal tubules aiding in the control of dentin hypersensitivity (DH). Spheroidal Carbonated apatite nanoparticles (N-CAP), with an average size of 20±5 nm diameter, were synthesized, characterized, and incorporated in a universal adhesive "All Bond Universal, Bisco, USA", in (2% weight) concentration. Er:YAG laser "Lightwalker, FOTONA, EU" was adjusted to an energy output of 40mJ/ pulse and pulse repetition of 10 Hz for 10 seconds. Dentin specimens were prepared from the buccal surface of 75 extracted sound human molars. The specimens were randomly divided into five groups (n=15) according to the surface treatment: Group (L): Laser only; Group (LB): Laser in combination with adhesive; Group (LBN): Laser in combination with adhesive loaded with N-CAP; Group (B): adhesive only; and Group (BN): adhesive loaded with N-CAP. Depth of penetration and occlusion of the dentinal tubules were assessed using Environmental Scanning Electron Microscope Examination (ESEM). One-way ANOVA was used to compare groups, followed by a pairwise test for multiple comparisons (α=0.05). Groups (LB), and (LBN) showed the highest mean of dentinal tubules' penetration, with a non-significant difference between them. In contrast, the specimens treated with laser only (L) showed the most minor penetration. The employment of ER-YAG laser irradiation with the adhesive loaded with N-CAP was evaluated to be effective in penetrating and occluding the opened dentinal tubules.

2-[5-Bromo-1-(3-chloro-benz-yl)-2-methyl-1H-indol-3-yl]acetic acid.

In the title compound, C18H15BrClNO2, the indole ring system forms a dihedral angle of 86.9 (2)° with the 3-chloro-benzyl ring. In the crystal, mol-ecules form inversion dimers connected via pairs of O-H⋯O hydrogen bonds.

3-(4-Bromo-phen-yl)-1-phenyl-1H-pyrazole-4-carbaldehyde.

The asymmetric unit of the title compound, C16H11BrN2O, contains two independent mol-ecules with slightly different geometries. The 4-bromo-benzene ring forms dihedral angles of 26.0 (2) and 39.9 (7)° with the pyrazole ring in the two mol-ecules while the phenyl ring is oriented at 19.7 (5) and 7.3 (0)° with respect to the pyrazole ring.

Microstructure and Mechanical Properties of Friction Stir Welded 2205 Duplex Stainless Steel Butt Joints.

Friction stir welding (FSW) as a solid-state process is an excellent candidate for high softening temperature materials welding; however, extending the tool life is required to make the process cost-effective. This work investigates the use of a high pin to shoulder ratio (65%) tungsten carbide (WC) tool for friction stir welding of 5 mm thick 2205 DSS to extend the tool life of this low-cost tool material. In addition, the effect of FSW parameters in terms of rotational rates, travel speeds, and downward forces on the microstructural features and mechanical properties of the welded joints were investigated. Characterization in terms of visual inspection, macro and microstructures, hardness, and tensile testing was conducted. The obtained results indicated that the combined rotational rate, travel speed, and downward force parameters govern the production of defect-free joints. The 2205 DSS friction stir welds show an enhancement in hardness compared to the base material. The stir zone showed a significantly refined grain structure of ferrite and austenite with the reduction in the average grain size from 8.8 µm and 13.3 µm for the base material to 2.71 µm and 2.24 µm, respectively. Moreover, this joint showed higher yield strength and ultimate tensile strength compared to the DSS as-received material.

Dentinal Tubule Occluding Efficacy Of Er: YAG Laser And Universal Adhesive Loaded With Nano-Carbonated Apatite

Abstract ER:YAG laser and experimental resin-based dental adhesive loaded with functionalized carbonated apatite filler were used in this study to evaluate the dentin interaction in terms of penetration and occlusion of the dentinal tubules aiding in the control of dentin hypersensitivity (DH). Spheroidal Carbonated apatite nanoparticles (N-CAP), with an average size of 20±5 nm diameter, were synthesized, characterized, and incorporated in a universal adhesive "All Bond Universal, Bisco, USA", in (2% weight) concentration. Er:YAG laser "Lightwalker, FOTONA, EU" was adjusted to an energy output of 40mJ/ pulse and pulse repetition of 10 Hz for 10 seconds. Dentin specimens were prepared from the buccal surface of 75 extracted sound human molars. The specimens were randomly divided into five groups (n=15) according to the surface treatment: Group (L): Laser only; Group (LB): Laser in combination with adhesive; Group (LBN): Laser in combination with adhesive loaded with N-CAP; Group (B): adhesive only; and Group (BN): adhesive loaded with N-CAP. Depth of penetration and occlusion of the dentinal tubules were assessed using Environmental Scanning Electron Microscope Examination (ESEM). One-way ANOVA was used to compare groups, followed by a pairwise test for multiple comparisons (α=0.05). Groups (LB), and (LBN) showed the highest mean of dentinal tubules' penetration, with a non-significant difference between them. In contrast, the specimens treated with laser only (L) showed the most minor penetration. The employment of ER-YAG laser irradiation with the adhesive loaded with N-CAP was evaluated to be effective in penetrating and occluding the opened dentinal tubules.

Resumo O laser ER-YAG e o adesivo dentário experimental à base de resina carregado com carga de apatita carbonatada funcionalizada foram usados neste estudo para avaliar a interação com a dentina em termos de penetração e oclusão dos túbulos dentinários, auxiliando no controle da hipersensibilidade dentinária (HD). Nanopartículas de apatita carbonatada esferoidal (N-CAP), com tamanho médio de 20±5 nm de diâmetro, foram sintetizadas, caracterizadas e incorporadas em um adesivo universal "All Bond Universal, Bisco, EUA", na concentração de 2% em peso. O laser Er:YAG "Lightwalker, FOTONA, EU" foi ajustado para uma saída de energia de 40mJ/pulso e repetição de pulso de 10 Hz por 10 segundos. Os espécimes de dentina foram preparados a partir da superfície vestibular de 75 molares humanos sadios extraídos. Os espécimes foram divididos aleatoriamente em cinco grupos (n=15) de acordo com o tratamento da superfície: Grupo (L): Somente laser; Grupo (LB): Laser em combinação com adesivo; Grupo (LBN): Laser em combinação com adesivo carregado com N-CAP; Grupo (B): somente adesivo; e Grupo (BN): adesivo carregado com N-CAP. A profundidade de penetração e a oclusão dos túbulos dentinários foram avaliadas por meio do Exame de Microscópio Eletrônico de Varredura Ambiental (ESEM). ANOVA de um fator foi usada para comparar os grupos, seguida pelo teste de pares para comparações múltiplas (α=0,05). Os grupos (LB) e (LBN) apresentaram a maior média de penetração dos túbulos dentinários, com uma diferença não significativa entre eles. Em contraste, os espécimes tratados apenas com laser (L) apresentaram menor penetração. O emprego da irradiação do laser ER-YAG com o adesivo carregado com N-CAP foi avaliado como eficaz na penetração e oclusão dos túbulos dentinários abertos.

Modified acidic nonsteroidal anti-inflammatory drugs as dual inhibitors of mPGES-1 and 5-LOX.

mPGES-1 is a promising target for development of new anti-inflammatory drugs. We aimed to create mPGES-1 inhibitors by modifying the structure of NSAIDs by replacing the carboxylic acid functionality by sulfonamide moieties. Compounds were also tested for 5-LOX inhibition. The most potent mPGES-1 inhibitor was lonazolac derivative 22 (IC50 = 0.16 µM), while the best 5-LOX inhibition was attained by indomethacin derivative 17 (IC50 = 0.9 µM). Inhibition of COX-1 activity was completely removed.