Compact 20-pass thin-disk multipass amplifier stable against thermal lensing effects and delivering 330 mJ pulses with M2 < 1.17.

We report on an Yb:YAG thin-disk multipass amplifier delivering 100 ns long pulses at a central wavelength of 1030 nm with an energy of 330 mJ at a repetition rate of 100 Hz. The beam quality factor at the maximum energy was measured to be M2 < 1.17. The small signal gain is 21.7, and the gain at 330 mJ was measured to be 6.9. The 20-pass amplifier is designed as a concatenation of stable resonator segments in which the beam is alternately Fourier transformed and relay-imaged back to the disk by a 4f-imaging optical scheme stage. The Fourier transform propagation makes the output beam robust against spherical phase front distortions, while the 4f-stage is used to compensate the thermal lens of the thin-disk and to reduce the footprint of the amplifier.

Effect of multiple firings on optical and mechanical properties of Virgilite-containing lithium disilicate glass-ceramic of varying thickness.

OBJECTIVES: To investigate the effect of multiple firings on color, translucency, and biaxial flexure strength of Virgilite-containing (Li0.5Al0.5Si2.5O6) lithium disilicate glass ceramics of varying thickness. MATERIALS AND METHODS: Sixty discs were prepared from Virgilite-containing lithium disilicate blocks. Discs were divided according to thickness (n = 30) into T0.5 (0.5 mm) and T1.0 (1.0 mm). Each thickness was divided according to the number of firing cycles (n = 10); F1 (Control group): 1 firing cycle; F3: 3 firing cycles, and F5: 5 firing cycles. The discs were tested for color change (ΔE00) and translucency (TP00) using a spectrophotometer. Then, all samples were subjected to biaxial flexure strength testing using a universal testing machine. Data were collected and statistically analyzed (α = 0.5). For chemical analysis, six additional T0.5 discs (2 for each firing cycle) were prepared; for each firing cycle one disc was subjected to X-ray diffraction analysis (XRD) and another disc was subjected to Energy dispersive X-ray spectroscopy (EDX) and Scanning electron microscope (SEM). RESULTS: Repeated firing significantly reduced the translucency of F3 and F5 compared to F1 in T0.5 (p < 0.001), while for T1.0 only F5 showed a significant decrease in TP00 (p < 0.001). For ΔE00, a significant increase was recorded with repeated firings (p < 0.05) while a significant decrease resulted in the biaxial flexure strength regardless of thickness. CONCLUSIONS: Repeated firings had a negative effect on both the optical and mechanical properties of the Virgilite-containing lithium disilicate glass ceramics. CLINICAL RELEVANCE: Repeated firings should be avoided with Virgilite-containing lithium disilicate ceramics to decrease fracture liability and preserve restoration esthetics.

Marginal adaptation and fracture resistance of virgilite-based occlusal veneers with varying thickness.

STATEMENT OF PROBLEM: CAD/CAM occlusal veneers have been developed for minimally invasive prosthetic restoration of eroded teeth. Marginal adaptation and fracture resistance are crucial for the long-term survivability and clinical success of such restorations. Virgilite-based lithium disilicate glass-ceramic is a newly introduced material with claims of high strength. However, constructing occlusal veneers from this material of varying thickness has not been investigated. PURPOSE: The current study aimed to assess the impact of CAD/CAM occlusal veneer thickness and materials on marginal adaptation and fracture resistance. MATERIALS AND METHODS: Thirty-two occlusal veneers were constructed and divided into two groups (n = 16) based on the CAD/CAM material into Brilliant Crios and CEREC Tessera. Each group was further subdivided into two subgroups (n = 8) according to the thickness: 0.6 and 0.9 mm. Occlusal veneers were bonded to epoxy resin dies. The marginal gap was evaluated before and after thermodynamic aging. Fracture resistance and failure mode were evaluated for the same samples after aging. Marginal adaptation was analyzed using the Mann-Whitney U test. Fracture resistance was analyzed using Weibull analysis (α = 0.05). RESULTS: The marginal gap was significantly increased following thermodynamic aging for tested groups (P < 0.001). CEREC Tessera showed a significantly higher marginal gap than Brilliant Crios before and after aging for both thicknesses (P < 0.05). CEREC Tessera recorded lower significant fracture load values compared to Brilliant Crios (P < 0.05). CONCLUSIONS: Both CEREC Tessera and Brilliant Crios demonstrated clinically accepted marginal gap values. All groups showed fracture resistance values higher than the average masticatory forces in the premolar region except for 0.6 mm CEREC Tessera. CLINICAL IMPLICATIONS: Reinforced composite occlusal veneers demonstrated more favorable outcomes in terms of marginal gap and fracture resistance at both tested thicknesses compared to virgilite-based lithium disilicate glass-ceramic. Additionally, caution should be exercised during the construction of occlusal veneers from virgilite-based lithium disilicate glass-ceramic with reduced thickness.

Injection-seeded high-power Yb:YAG thin-disk laser stabilized by the Pound-Drever-Hall method.

We demonstrate an injection-seeded thin-disk Yb:YAG laser at 1030 nm, stabilized by the Pound-Drever-Hall (PDH) method. We modified the PDH scheme to obtain an error signal free from Trojan locking points, which allowed robust re-locking of the laser and reliable long-term operation. The single-frequency pulses have 50 mJ energy (limited to avoid laser-induced damage) with a beam quality of M2 < 1.1 and an adjustable length of 55-110 ns. Heterodyne measurements confirmed a spectral linewidth of 3.7 MHz. The short pulse build-up time (850 ns) makes this laser suitable for laser spectroscopy of muonic hydrogen, pursued by the CREMA collaboration.

Oxytocin versus a combination of tranexamic acid and ethamsylate in reducing intraoperative bleeding during abdominal myomectomy: a randomized clinical trial.

OBJECTIVE: Myomectomy is the preferred surgical approach to manage uterine fibroids. However, uterine fibroids are highly vascular tumors and, consequently, extremely susceptible to problems from myomectomy-related hemorrhage. Hence, we aim to compare oxytocin efficacy and safety profile versus tranexamic acid (TA) with ethamsylate for reducing bleeding during myomectomy. METHODS: This randomized, double-blinded multicenter study was performed between 20th August 2020 and 20th October 2020 at El-Galaa Teaching Hospital, El Hussein University Hospital, Al-Azhar University Hospitals of Assiut, and Al-Azhar University Hospitals of Damietta. One hundred and eighty patients were enrolled and divided into three groups: group (1) received an injection of 30 IU of oxytocin in 500 ml of normal saline; group (2) received injections of 1 g of TA, 250 mg of Ethamsylate, and 110 ml of normal saline IV; and group (3) received an injection of 110 ml of normal saline IV just before surgical incision. RESULTS: In 180 premenopausal women, oxytocin and TA with ethamsylate had no significant value in lowering intraoperative blood loss compared with the placebo for abdominal myomectomy (666.25 ± 183.03, 630.72 ± 145.83, and 646.67 ± 168.92, respectively (P = 0.506)). Non-significant trends were observed for a reduction in operation time (P = 0.760), intra/postoperative blood transfusion (P = 0.624), hospital stay (P = 0.986), postoperative fever (P = 0.659), and wound infection (P = 1). CONCLUSION: Oxytocin and TA with ethamsylate had no significant value in lowering intraoperative blood loss compared with the placebo for abdominal myomectomy which opens a new question about the role of the use of the hemostatic drug during myomectomy especially in centers with limited resources and had higher rates. TRIAL REGISTRATION: The study was registered on Pan African Clinical Trials Registry with the following number: PACTR202008739887429 and was approved on 24/08/2020.

Tooth auto-transplantation: A bibliometric analysis of the top 100 most-cited articles.

BACKGROUND/AIM: Tooth auto-transplantation has recently gained high clinical acceptance. The aim of this study was to identify the top 100 most-cited articles regarding tooth auto-transplantation, to analyse multiple citations and publication metrics and to outline the historical scientific advancements in this field. MATERIALS AND METHODS: An advanced search of the Clarivate Analytics' Web of Science 'Core Collection' and Elsevier's Scopus databases utilising specific keywords related to tooth auto-transplantation between 1971 and 2021 was performed. The retrieved articles were ranked in descending order based on their Web of Science citation counts and further cross-matched with citation data from Scopus. The extracted data included citation counts, citation density, level of evidence, year of publication, contributing authors names and institutes, corresponding author's address, journal of publication, journal local citations index, cumulative growth index, keywords and keywords Plus. Data analysis was performed using descriptive statistics and graphical mapping. RESULTS: A total of 1290 articles were retrieved. The top 100 most-cited articles received a total of 4899 (Web of Science) and 5250 (Scopus) citations. Among these, cohort studies (29%) and case series (18%) were the most common study designs. Scandinavian countries produced major contributions in defining the top 100 most-cited articles and ranked within the top 5 countries based on the number of publications and citations per year. The greatest contributing authors were Schwartz O (n = 12), Andreasen JO (n = 8) and Paulsen HU (n = 6), and they were affiliated with Copenhagen, Denmark. The top contributing journals were American Journal of Orthodontics and Dentofacial Orthopedics, International Journal of Oral and Maxillofacial Surgery, Oral Surgery Oral Medicine Oral Pathology Oral Radiology, European Journal of Orthodontics, Dental Traumatology and Journal of Oral and Maxillofacial Surgery. CONCLUSION: This bibliometric analysis revealed a large geographical scientific interest and broad development in the field of tooth auto-transplantation spanning multiple dental disciplines.

Evaluation of different decontamination procedures on bond strength to sound and caries affected dentin using "no-wait" universal adhesive.

BACKGROUND: Current study aimed to evaluate the effect of different decontamination procedures on micro-shear bond strength (µSBS) of sound (SoD) and caries-affected dentin (CAD) of two universal adhesives after blood-saliva contamination. METHODS: One hundred and eighty bovine anterior teeth were prepared and allocated into the respective groups according to tested dentin substrates [SoD, CAD], universal adhesives [Clearfil Bond Universal Quick (UBQ), All-Bond-Universal (ABU)], adhesive contamination stage [none, contamination before and after adhesives light-curing], and according to decontamination procedures [no decontamination, water rinsing, adhesive rebond, Ethylenediaminetetraacetic acid (ETDA) and chlorhexidine (CHX) application]. Universal adhesives were applied according to manufacturer instructions in self-etch (SE) bonding mode. Four composite microrods were built for each tooth. Specimens were kept in distilled water for 24 hours at 37°C before testing µSBS. Four-way ANOVA and Tukey HSD tests were used for data analysis. RESULTS: A statistically significant difference between contamination stages of both universal adhesives at different decontamination procedures for SoD and CAD. Highest µSBS was recorded for UBQ control group at SoD, while the least was recorded for light-cured ABU upon water rinsing decontamination procedure of CAD. CONCLUSIONS: Proper cavity isolation is mandatory to avoid possible contamination which can dramatically affect µSBS. CHX is a potent cavity decontaminant that can restore different dentin substrates bond strength. EDTA presents a promising substitute. UBQ adhesive showed better bonding performance than ABU to both dentin substrates. Application of regular cavity decontamination approaches is highly advised in daily practice to avoid possible detrimental effect of accidental cavity contamination.

Effect of silver diamine fluoride activation on bond strength to root dentin.

BACKGROUND: To investigate the effect of silver diamine fluoride (SDF) application and activation on the bond strength of gutta-percha to dentin and resin bonded post to dentin. METHODS: Thirty-six human premolar teeth were used. The coronal part tooth was removed, and endodontic mechanical preparation was performed for all the teeth. The teeth were divided according to final rinse protocol (n = 9) as follows: Control group; no SDF application, SDF/NA; 38% SDF as a final rinse with no activation, SDF/MDA; 38% SDF as a final rinse with manual dynamic activation and SDF/US; 38% SDF as a final rinse with ultrasonic activation. Root canal obturation using lateral condensation technique followed by fiber post insertion after 48 h in the root canal after corresponding preparations. The roots were cut with a low-speed precision saw creating 2 mm thickness sections. A total of 4 sections were obtained from each tooth, 2 coronal specimens (with post) and 2 apical specimens (with Gutta percha). Each specimen was subjected to push-out bond strength test with a universal testing machine. Data were analyzed using two-way ANOVA. RESULTS: The Push-out bond strength at the apical root section was significantly higher in SDF/MDA and SDF/US groups compared to control group. While for the coronal part, all SDF treated specimen showed reduced Push-out bond strength. CONCLUSION: SDF application as final rinse may reduce the bonding performance between fiber post and dentine. Activation with manual and ultrasonic methods improved the bond strength at the apical root section.

Color stability of two different resin matrix ceramics: randomized clinical trial.

BACKGROUND: One of the most common causes of aesthetic failure and restoration replacement is the tooth restorations color mismatch specifically after aging. METHODS: One hundred and two participants with endodontically treated first molar were selected clinically. The patients were randomly splited into two groups and restored either with Cerasmart hybrid ceramic or Vita Enamic polymer infiltrated ceramic network (PICN) crowns and cemented using dual cure adhesive cement. The color difference (ΔE) values after cementation at 0 (Baseline), 6, and 12 months of use were obtained by quantification of L*, a*, and b* values with a digital spectrophotometer. Mann-Whitney test used to compare between tested groups at each time point and between (α = 0.05). RESULTS: At 6 months follow-up intervals, Vita Enamic group showed the highest significant ∆L* (p = 0.035) and ∆a* (p < 0.001) compared to Cerasmart group. ∆b* and ∆E showed no significant difference between both groups (p > 0.05). Furthermore, all color parameters of both groups showed statistically significant difference at 12 months follow-up intervals. After 12 months, Vita Enamic restorations presented higher color change compared to Cerasmart restorations with a (p-value of 0.0120). When comparing the total color difference ∆Et through-out the follow-up intervals of Vita Enamic & Cerasmart groups, there were insignificant difference (p = 0.263). CONCLUSION: Both hybrid materials demonstrated comparable color stability after 1 year of clinical service within clinical acceptance range. However, Cerasmart demonstrated a better colour stability after 1 year. TRIAL REGISTRATION: ClinicalTrials.gov (ID: NCT05501808) 15/8/ 2022- 'retrospectively registered'.

MDP-salts as an adhesion promoter with MDP-primers and self-adhesive resin cement for zirconia cementation.

PURPOSE: To evaluate the effect of zirconia priming with MDP-Salt before MDP containing primers and self-adhesive cement on the shear bond strength. MATERIALS AND METHODS: Fully sintered high translucent zirconia specimens (n = 120) were assigned into 2 groups (n = 60 each): Control (No Pretreatment) and Methacryloyloxydecyl dihydrogen phosphate salt (MDP-Salt) pretreated. Each group was divided into 3 subgroups (n = 20) according to cementation protocol: 1) MDP + Silane primer and conventional resin cement, 2) MDP+ Bisphenyl dimethacrylate (BPDM) primer and conventional resin cement, and 3) MDP containing self-adhesive resin cement. Shear bond strength (SBS) was measured after 10,000 thermocycling. Contact angle was measured for tested groups. Surface topography was assessed using a 3D confocal laser scanning microscope (CLSM). Weibull analysis was performed for SBS and one-way ANOVA for contact angle and surface topography measurements (α = 0.05). RESULTS: The use of MDP-Salt significantly improved the SBS (p < .05) for all tested subgroups. Self-adhesive cement showed an insignificant difference with MDP + Silane group for both groups (p > .05). MDP + BPDM showed a significantly lower characteristic strength compared to self-adhesive resin cement when both were pretreated with MDP-Salt. No difference between all tested groups in the surface topographic measurements while MDP-Salt showed the highest contact angle. CONCLUSION: MDP-Salt pretreatment can improve bonding performance between zirconia and MDP containing products.

Prevalence and associated factors of anemia among pregnant women and the impact of clinical pharmacist counseling on their awareness level: A cross sectional study.

Anemia during pregnancy is a worldwide problem that affects females worldwide. There is not enough data on the magnitude of this health problem in Al-Madinah city in Saudi Arabia. This study aimed to assess the prevalence and associated factors related to anemia during pregnancy in Al-Madinah city. In addition, assessed the impact of counseling by clinical pharmacist on anemic pregnant females. 300 pregnant females were assessed for anemia based on their hemoglobin level in a descriptive cross-sectional study. Those females were further interviewed to identify associating factors related to presence of anemia during pregnancy. Anemic females were randomized to receive either counseling by the clinical pharmacist in addition to the standard of care (interventional group) or standard of care without counseling (control group). Our result showed that 44% of pregnant women were anemic upon recruitment. Pregnant females of low socioeconomic status, those during the first trimester, multipara females, and those who did not receive nutritional education during pregnancy showed significantly higher odds of developing anemia. Clinical pharmacist-led counseling program significantly improved adherence with iron regimen (p-value < 0.01) and significantly increased patients' hemoglobin level 30-days after the intervention (p-value < 0.001).

Identifying 3rd larval stages of common strongylid and non-strongylid nematodes (class: Nematoda) infecting Egyptian equines based on morphometric analysis.

Strongylid and non-strongylid nematodes are one of the most important parasites infecting equines. The traditional method to identify these nematodes is through coproscopy and fecal culture. Because of the scarcity of data published in Egypt discussing the morphometric features of infective 3rd larvae of these nematodes, this study aims to provide a morphometric key for L3 of common strongylid and non-strongylid nematodes infecting Egyptian equines. For this reason, we cultured fecal samples containing GINs eggs and 3rd larval stages were identified based on their morphology (i.e., shape and number of intestinal cells (IC), shape of the esophagus, and shape of the tail sheath) in addition to computing their dimensions (i.e., length of larvae with sheath, length of the esophagus, length of intestinal cells, and body breadth). We identified 3rd larval stages of four strongylid nematodes (Cyathostomum sensu lato, Strongylus vulgaris, Strongylus equinus, and Strongylus edentatus) as well as two non-strongylid nematodes (Strongyloides westeri, and Trichostrongylus axei). Statistically, our results revealed significant differences in terms of total length, body width, esophagus length, and gut length among 3rd larvae identified in the current study. The combination of both morphological and metric keys will allow the better identification of common strongylid and non-strongylid nematodes infecting equines.

Physiological response and oxidative stress of grass carp (Ctenopharyngodon idellus) under single and combined toxicity of polystyrene microplastics and cadmium.

The harm of microplastics (MPs) to aquatic ecosystems is caused by their stable and non-degradable properties. Additionally, the pollutants such as heavy metals in the water are easy to be adsorbed on their surface with their small particle size and large specific surface area, resulting in environmental pollution. Therefore, the study on the mixture toxicity of MPs and heavy metals has theoretical significance for the risk assessment of aquatic ecosystems. In the present study, 10 nm polystyrene (PS) and cadmium (Cd) were used, and their individual and mixture acute toxicities on grass carp (Ctenopharyngodon idellus) were examined. The results indicated that the mortality of the fish increased with the concentration from 10 mg L-1 to 20 mg L-1, and the existence of PS-MPs elevated the Cd concentrations in the fish and accelerated the death. Whether the Cd and/or the PS-MPs concentrations caused varying degrees of damage to the gills, kidney, liver, and muscles of the grass carp, especially under the highest concentrations (20 mg L-1 Cd + 300 µg L-1 PS-MPs). Moreover, low concentrations of PS-MPs alone (30 µg L-1 PS-MPs) significantly increased the superoxide dismutase (SOD) activity in the kidney and liver, reaching 12.43% and 14.38%, respectively (P < 0.05). The peroxidase (POD) activity was increased only in the kidney, up to 25.95% (P < 0.05). Also, significant reductions in SOD and POD activities were observed in the combination of high concentration of Cd (20 mg L-1) and 300 µg L-1 PS-MPs (P < 0.05). To the best of our knowledge, there are few studies on the impact of combined toxicity of PS-MPs and Cd on grass carp under laboratory conditions. Therefore, these findings may provide a theoretical guarantee for pollution prevention and control in the aquatic ecosystem.

Influence of 10-methacryloyloxydecyl dihydrogen phosphate (MDP) incorporated experimental cleaners on the bonding performance of saliva-contaminated zirconia ceramic.

OBJECTIVES: To assess the efficacy of experimental cleaners containing 10-methacryloyloxydecyl dihydrogen phosphate (MDP) on the saliva decontamination of ceramic and their influence in restoring zirconia's adherence to resin cement. MATERIALS AND METHODS: Four hundred sixty alumina-blasted zirconia specimens were categorized into saliva-contaminated and uncontaminated groups which were treated with ceramic primer (P), experimental cleaner 1 (C1), C1 followed by P (C1P), experimental cleaner 2 (C2), and C2 followed by P (C2P). Stainless-steel rods were then attached to the specimens using PanaviaV5 cement (Kuraray Noritake Dental; Tokyo, Japan). Tensile bond strength (TBS) test was performed after 24 h and 5000 thermocycling processes. X-ray photoelectron spectroscopy (XPS) analysis and contact angle measurement of the specimen were performed. The TBS data were analyzed by Weibull analysis and three-way ANOVA. Contact angle data were analyzed by two-way ANOVA (α = 0.05). RESULTS: C2P groups showed the highest TBS in all conditions among tested groups. Saliva contamination led to a significant reduction of TBS in primer- and cleaner-treated groups, with no significant impact on C2P. Adhesive failure was predominant in contaminated groups except with the C1P and C2P groups. XPS revealed that a nitrogen peak was observed on contaminated groups but not in primed groups. The contact angle was significantly affected by saliva contamination, the cleaners, and/or ceramic primer usage (p < 0.001). CONCLUSIONS: The MDP cleaner followed by the MDP primer protocol may overcome the effect of saliva contamination and improve the resin-ceramic bond strength. CLINICAL RELEVANCE: It is recommended to use a combination of MDP-containing cleaner 2 and ceramic primer as a chair-side chemical pretreatment for zirconia substrate with or without saliva contamination.

Dentin anti-demineralization potential of surface reaction-type pre-reacted glass-ionomer filler containing self-adhesive resin cement.

OBJECTIVE: To investigate the anti-demineralization potential of a newly developed surface reaction-type pre-reacted glass-ionomer (S-PRG) filler containing self-adhesive resin cement against acidic attacks on the dentin surface. MATERIALS AND METHODS: A total of 32 bovine teeth were used. Cavities were prepared on crown dentin slaps and filled with three self-adhesive resin cement: (1) S-PRG-based cement, (2) Si-based cement, and (3) RelyX cement. Specimens were then subjected to pH cycling for 28 days, and the depth of demineralization was assessed using swept-source optical coherence tomography (SS-OCT) after 7, 14, 21, and 28 days. Sixty-four root dentin blocks were divided into four groups and then subjected to a pH cycling procedure with the aforementioned three material blocks and one negative control. The mineral loss was observed using transverse microradiography (TMR), and the surface microhardness (SMH) test was conducted to investigate the mechanical properties of treated dentin surfaces. RESULTS: The depth of demineralization for the S-PRG-based cement was significantly lower than that of the Si-based cement after 7, 21, and 28 days. Conversely, the RelyX cement was not significantly different from the Si-based cement after 7, 14, and 21 days (p < 0.05). Regarding the TMR and SMH test, the S-PRG-based cement showed the least mineral loss with the highest resistance to acidic challenge. CONCLUSION: The S-PRG filler containing resin cement can reduce mineral loss and promote remineralization of dentin substrate and has the potential to preserve dentin integrity and resist acidic attack. Clinical significance Self-adhesive resin cement containing S-PRG fillers maintained the surface integrity of dentin after exposure to 28 days of acidic challenge with a significant anti-demineralization effect.

The effects of different silicatization and silanization protocols on the bond durability of resin cements to new high-translucent zirconia.

OBJECTIVE: The aim of this study was to assess the influence of different silicatization protocols with various silane treatment methods on the bond performance to high-translucent zirconia. MATERIALS AND METHODS: High-translucent zirconia specimens were assigned to five groups according to mechanical surface pretreatment: as-sintered (Con), 0.2 MPa alumina sandblasting (AB2), tribochemical silica coating (TSC), 0.2 and 0.4 MPa glass bead air abrasion (GB2) and (GB4). Each group was subjected to 4 different cementation protocols: Panavia SA Universal (SAU), Panavia SA plus (SAP), silane + SAP (S-SAP), and Universal adhesive + SAP (U-SAP). Tensile bond strength (TBS) was measured after 24 h and 10,000 thermocycling (TC). Surface topography, surface energy, and elemental composition of the abraded zirconia surface analyses were completed. TBS data was analyzed using the Weibull analysis method. Surface roughness and surface energy were compared by one-way ANOVA analysis of variance (α = 0.05). RESULTS: After 24 h, higher TBS was achieved with all cementation protocols in AB2 and TSC, also, in GB2 with all protocols except U-SAP, and in GB4 with SAU and S-SAP. After aging, GB4/S-SAP, GB2/S-SAP, AB2/U-SAP, and TSC/S-SAP showed the highest bond strength. GB groups showed the lowest surface roughness and highest surface energy. CONCLUSION: Glass bead abrasion achieved the durable bond strength to high-translucent zirconia using a separate silane coupling agent while altered surface chemistry, surface energy, and roughness without effect on morphology. CLINICAL RELEVANCE: Glass bead air abrasion is an alternative to alumina sandblasting and tribochemical silica coating and improves bond strength to high translucent zirconia.

Additive effects of touch-activated polymerization and extended irradiation time on bonding of light-activated adhesives to root canal dentin.

STATEMENT OF PROBLEM: The bonding of light-activated adhesives to root canal dentin with an additional touch-polymerization activator has been insufficiently examined. PURPOSE: The purpose of this in vitro study was to investigate the effect of touch-polymerization activators and extended light-irradiation time on the microtensile bond strength (µTBS) of light-activated adhesives. MATERIAL AND METHODS: Post cavities were prepared in 50 extracted mandibular premolars and bonded using Prime&Bond Universal (PBU); PBU+Self Cure Activator (SCA); Clearfil SE Bond 2 (SEB); SEB+Clearfil DC Activator (DCA); or Clearfil Universal Bond Quick ER (UBQ). After light-irradiation for 10 or 20 seconds, the post cavities were filled with dual-activated resin core materials. Eight beams were prepared per specimen and subjected to the µTBS test. The µTBS data were analyzed by using 3-way ANOVAs with the Bonferroni correction (α=.05). RESULTS: The 3-way ANOVAs indicated that the use of touch-polymerization activators (SCA and DCA) significantly increased the µTBS of PBU and SEB in both the coronal (P=.015) and apical (P=.001) regions. The extension of light-irradiation time to 20 seconds significantly improved their µTBS in the apical region (P<.001), but not in the coronal region (P=.09). Light-irradiation for 20 seconds increased the µTBS of UBQ significantly in the coronal region (P=.014). CONCLUSIONS: Touch-polymerization activators improved the bond strength of light-activated adhesives to root canal dentin, especially when combined with an extended light-irradiation time.

Effect of contamination of bulk-fill flowable resin composite with different contaminants during packing on its surface microhardness and compressive strength: in vitro study.

BACKGROUND: Proper isolation and restoration of class V subgingival cavities are technique sensitive, thus the resin composite restoration is liable to contamination. This in vitro study was conducted to evaluate the surface microhardness and compressive strength of bulk-fill flowable resin composite after being contaminated during its packing. METHODS: Resin composite discs were prepared using split mold. The contaminated specimens were allocated into four groups (n = 20) according to the contaminant used: hemostatic agent (Group 1), alcohol (Group 2), artificial saliva (Group 3) and powdered gloves (Group 4). The non-contaminated specimens (n = 20) were used as control group. The surface microhardness and compressive strength of each group were tested 1-day post-photocuring (n = 5) and 1 month post-photocuring (n = 5). Values were presented as mean, standard deviation values and confidence intervals. RESULTS: The surface microhardness of all groups didn't show a significant difference for different tested groups except for alcohol which showed a significant reduction on surface microhardness compared to control at 1 day post-photocuring (p = 0.001). The highest compressive strength mean values at 1 day and 1 month post-photocuring were recorded in control groups (110.42 MPa and 172.87 MPa respectively), followed by alcohol groups, then hemostatic agent groups, followed by artificial saliva with the least value recorded in powdered gloves groups (56.71 MPa and 49.5 MPa respectively). CONCLUSIONS: Contamination of bulk-fill flowable resin composite with hemostatic agent, alcohol, artificial saliva, or powdered gloves during its packing decreased its compressive strength after 1 month post-photocuring rather than affecting its surface microhardness.

Effect of Air-Particle Abrasion Protocol and Primer on The Topography and Bond Strength of a High-Translucent Zirconia Ceramic.

PURPOSE: To evaluate effect of air-particle abrasion protocol and primer on surface topography and bond strength of resin cement to high-translucent zirconia ceramics. MATERIALS AND METHODS: Two hundred disk-shaped high-translucent zirconia specimens of 5Y-PSZ were prepared. The specimens were assigned to 5 groups in terms of particle type and air-particle abrasion pressure: (1) control, (2) alumina with 0.2 MPa-air pressure [AB-0.2], (3) alumina with 0.4 MPa-air pressure [AB-0.4], (4) glass beads with 0.2 MPa-air pressure [GB-0.2], and (5) glass beads with 0.4 MPa-air pressure [GB-0.4]. Two different primers 1% MDP (Experimental) and MDP-silane primer (Clearfil Ceramic Primer Plus) was also tested. Stainless steel rods were bonded to the 5Y-PSZ specimens with PANAVIA V5. For each group, the tensile bond strength (TBS) was measured after 24-hour water storage (n = 10) and after 5000 thermal-cycling (n = 10) at crosshead speed of 2 mm/min. The data were statistically analyzed using Weibull analysis. Surface roughness (Sa) was measured using a 3D-Laser Scanning Confocal Microscope (n = 5) and analyzed by t-test with Bonferroni correction. Surface topography using scanning electron microscopy (SEM) and surface elemental analysis using energy dispersion spectroscopy (EDX), and cross-section SEM at the interface with composite cement were also investigated. RESULTS: In MDP-silane groups, the highest TBS was observed in AB-0.4 after 24 hours and GB-0.4 after thermal-cycling (p < 0.05). In MDP groups, AB groups resulted in the significantly higher TBS than GB groups (p < 0.05). AB-0.4 group showed the highest Sa value compared to all groups (p < 0.005), meanwhile GB groups did not show different Sa compared to control (p > 0.005). CONCLUSION: Air-abrasion with different particle and blasting pressure can improve bonding to zirconia with proper primer selection. Particularly, glass beads abrasion followed by MDP-silane primer and alumina abrasion followed by MDP primer alone provided stable bond strength of resin cement to high-translucent zirconia after aging. High-translucent zirconia abraded with glass beads achieves a desirable bonding performance without creating surface microcracks which may hinder zirconia's mechanical properties.

Azimuthally polarized picosecond vector beam with 1.7 kW of average output power.

We report on a thin-disk multipass amplifier delivering azimuthally polarized, 7.8 ps short, laser pulses at an average power and with pulse energies of up to 1.7 kW and 5.8 mJ, respectively. High polarization purity was achieved by compensating for the arbitrary linear phase shifts that are introduced by tilted optical elements.