The Effect of Colloidal Silica and Glaze Coatings on the Adhesion of Zirconia with Various Ytrria Concentration.

PURPOSE: This study evaluated the effect of coating traditional and translucent Y-TZP with an industrial nanometric colloidal silica or glaze before or after sintering on the adhesion of zirconia with various ytrria concentration. MATERIALS AND METHODS: Specimens of Y-TZP with 3% and 5% yttria were subdivided into 5 groups (n=10), according to the coating applied and moment of application (before or after Y-TZP sintering): Control (no coating), Colloidal Silica/Sintering, Sintering/Colloidal Silica, Glaze/Sintering, Sintering/ Glaze. Lithium disilicate (LD) was used as positive control. Except for Y-TZP controls, groups were conditioned with silane before cementation with a self-adhesive resin cement. After 24 hours, the shear bond strength and failure analysis were performed. Also, analysis of specimens' surface was accomplished with SEM-EDX. Kruskal-Wallis and Dunn tests were applied to analyze differences between groups (p⟨0.05). RESULTS: Overall, the worst and best values of shear bond strength test were control and glaze after sintering groups. Different morphological and chemical aspects were observed in SEM-EDX analysis. CONCLUSIONS: Coating Y-TZP with colloidal silica showed unsatisfactory results. In 3Y-TZP, the surface treatment associated with the best adhesion values was the application of glaze after zirconia sintering. However, in 5Y-TZP, glaze application can be performed before or after the zirconia sintering to optimize clinical steps.

Efficacy of Er,Cr:YSGG Laser Application in Nonsurgical Treatment of Peri-implantitis: A Human Randomized Controlled Trial.

This investigation was designed to evaluate the efficacy of an erbium, chromium-doped yttrium, scandium, gallium and garnet (Er,Cr:YSGG) laser (laser group) compared to conventional mechanical debridement (control group) in the treatment of peri-implantitis. In a double-blinded, randomized, controlled clinical trial, 32 patients with 88 implants with peri-implantitis were randomly assigned to either group. Statistical analyses were performed at 9 months for both groups. The laser-treated group showed a statistically significant reduction in probing depth (PD) compared to the control group (P = .04), but no statistically significant differences were observed for clinical attachment level gain (P = .29) or reduction of bleeding on probing (P = .09). In the subgroup analysis, mandibular single implants with screw-retained restorations treated with Er,Cr:YSGG demonstrated a statistically significant decrease in PD (P < .05) compared to all other groups. A complete resolution of peri-implantitis was achieved in 21% of implants in the test group and 5% of implants in the control group. Er,Cr:YSGG laser is an efficacious therapeutic tool to treat peri-implantitis, achieving greater PD reduction than conventional mechanical debridement alone. Er,Cr:YSGG laser also showed increased benefits in the treatment of mandibular, screw-retained, and single-unit implants compared to the sole use of conventional mechanical debridement.

Comparative evaluation of combined efficacy of methylene blue mediated antimicrobial photodynamic therapy (a-PDT) using 660 nm diode laser versus Erbium-chromium-yttrium-scandium-gallium-garnet (Er, Cr: YSGG) laser as an adjunct to scaling and root planing on clinical parameters in supportive periodontal therapy: A randomized split-mouth trial.

AIM: The aim of this study was to evaluate combined efficacy of methylene blue mediated antimicrobial photodynamic therapy (a-PDT) using 660 nm diode laser versus Er, Cr: YSGG laser as an adjunct to scaling and root planing on improving the Probing depth (PD), Clinical attachment level (CAL), Plaque Index (PI) and Gingival Index (GI).clinical parameters in Supportive periodontal therapy. MATERIALS AND METHOD: In this split-mouth, double-blind, randomized controlled trial, we compared a-PDT versus Er,Cr:YSGG as an adjunct to scaling and root planning (SRP) with SRP alone in Supportive periodontal therapy. A total of 36 subjected were enrolled. In each patient, two quadrants constituted the control group (Group I - Scaling and root planing SRP alone), one site in other quadrant constituted the test group 1 (Group II - SRP followed by application of Er, Cr: YSGG laser), and another site in different quadrant constituted the test group 2 (Group III - SRP followed by antimicrobial Photodynamic therapy using diode laser). The diode laser was operated at a peak power of 70 mW using a 0.6 mm diameter fiber-optic tip. Each site was irradiated with a power density of 28 mW/cm2, for 10 s, thus delivering a total energy of 16.72 J/cm2 per tooth. Whereas, the Er,Cr:YSGG laser's parameters were set to 1 W of power, 10% air, and 15% water. The same procedure was repeated at 1st, 2nd and 3rd week for both the laser therapies. Plaque index (PI), Gingival index (GI), Probing depth (PD,) and Clinical attachment level (CAL) were measured by a single examiner at baseline and 3 months follow up. Inter group analysis of the parameters were done using One-way ANOVA and pairwise comparison was carried out by Tukey's post hoc test. Intra group analysis was performed using Students's paired t test. Statistical significance was set to p < 0.05. RESULTS: There were no significant differences between participants for clinical parameters at baseline. PI, GI PD, and CAL significantly improved at 3 months follow up compared to baseline in both the study groups (Group II - SRP + Er,Cr:YSGG, Group III - SRP + a-PDT) with P < 0.05. Adjunctive use of Er,Cr:YSGG laser with SRP showed better clinical outcomes than a-PDT with SRP. CONCLUSION: Nonsurgical periodontal therapy of chronic periodontitis using Er, Cr: YSGG, and a-PDT as an adjunct to SRP was significantly more effective than SRP alone in reducing PD, CAL, GI, and PI at 3 months follow up. Adjunctive use of Er,Cr:YSGG laser with SRP showed better clinical outcomes than a-PDT with SRP. However, the long-term positive benefits of the laser therapies are yet unknown and more research with longer follow-ups are required.

Dual-Responsive and ROS-Augmented Nanoplatform for Chemo/Photodynamic/Chemodynamic Combination Therapy of Triple Negative Breast Cancer.

Integrating chemodynamic therapy (CDT) and photodynamic therapy (PDT) into one nanoplatform can produce much more reactive oxygen species (ROS) for tumor therapy. Nevertheless, it is still a great challenge to selectively generate sufficient ROS in tumor regions. Meanwhile, CDT and PDT are restricted by insufficient H2O2 content in the tumor as well as by the limited tumor tissue penetration of the light source. In this study, a smart pH/ROS-responsive nanoplatform, Fe2+@UCM-BBD, is rationally designed for tumor combination therapy. The acidic microenvironment can induce the pH-responsive release of doxorubicin (DOX), which can induce tumor apoptosis through DNA damage. Beyond that, DOX can promote the production of H2O2, providing sufficient materials for CDT. Of note, upconversion nanoparticles at the core can convert the 980 nm light to red and green light, which are used to activate Ce6 to produce singlet oxygen (1O2) and achieve upconversion luminescence imaging, respectively. Then, the ROS-responsive linker bis-(alkylthio)alkene is cleaved by 1O2, resulting in the release of Fenton reagent (Fe2+) to realize CDT. Taken together, Fe2+@UCM-BBD exhibits on-demand therapeutic reagent release capability, excellent biocompatibility, and remarkable tumor inhibition ability via synergistic chemo/photodynamic/chemodynamic combination therapy.

Effectiveness of Nanohydroxyapatite on Demineralization of Enamel and Cementum Surrounding Margin of Yttria-Stabilized Zirconia Polycrystalline Ceramic Restoration.

INTRODUCTION: Prosthetic dentistry has shifted toward prevention of caries occurrence surrounding restorative margin through the anti-demineralization process. This study examines the ability of nanohydroxyapatite (NHA) gel and Clinpro (CP) on enhancing resistance to demineralization of enamel and cementum at margin of restoration. MATERIALS AND METHODS: Thirty extracted mandibular third molars were segregated at 1 mm above and below cementoenamel junction (CEJ) to separate CEJ portions and substituted with zirconia disks by bonding to crown and root portions with resin adhesive. The enamel and cementum area of 4 × 4 mm2 neighboring zirconia was applied with either NHA or CP, while one group was left no treatment (NT) before demineralized with carbopal. Vickers hardness (VHN) of enamel and cementum was evaluated before material application (B M), after material application (A M), and after demineralization (A D). Analysis of variance (ANOVA) and post hoc multiple comparisons were used to justify for the significant difference (α = 0.05). Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were determined for surface evaluations. RESULTS: The mean ± SD of VHN for B M, A M, and A D for enamel and cementum was 393.24 ± 26.27, 392.89 ± 17.22, 155.00 ± 5.68 and 69.89 ± 4.59, 66.28 ± 3.61, 18.13 ± 0.54 for NT groups, respectively, 390.10 ± 17.69, 406.77 ± 12.86, 181.55 ± 7.99 and 56.01 ± 9.26, 62.71 ± 6.15, 19.09 ± 1.16 for NHA groups, respectively, and 387.90 ± 18.07, 405.91 ± 9.83, 188.95 ± 7.43 and 54.68 ± 7.30, 61.81 ± 4.30, 19.22 ± 1.25 for CP groups, respectively. ANOVA indicated a significant increase in anti-demineralization of enamel and cementum upon application of NHA or CP (p < 0.05). Multiple comparisons indicated the capability in inducing surface strengthening to resist demineralization for enamel and cementum of NHA which was comparable to CP (p > 0.05) as evidenced by SEM and XRD data indicating NHA and CP deposition and crystallinity accumulation. CONCLUSION: NHA and CP were capable of enhancing anti-demineralization for enamel and cementum. The capability in resisting the demineralization process of NHA was comparable with CP. NHA was highly recommended for anti-demineralization for enamel and cementum surrounding restorative margin.

Metabolic activity assessment by 18 F-fluorodeoxyglucose positron emission tomography in patients with hepatocellular carcinoma undergoing Yttrium-90 transarterial radioembolization.

BACKGROUND AND AIM: 18 F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) is a functional image technique that can inform clinical decisions related to prognosis. We investigated the predictive role of 18 F-fluorodeoxyglucose PET/CT in patients with hepatocellular carcinoma (HCC) undergoing Yttrium-90 (Y-90) transarterial radioembolization (TARE). METHODS: Patients with HCC treated with TARE and pre-TARE PET/CT scan were recruited between 2009 and 2013. Maximum standardized uptake value and tumor-to-non-tumorous liver uptake ratio (TLR) were measured. Tumor response was evaluated in accordance with modified RECIST criteria at 3-month intervals after Y-90 TARE. RESULTS: Forty patients were included in the final analysis. The median age was 56.5 years and male predominant. Disease control in treated lesion was achieved in 82.5% (n = 33) of patients. During median 18.3-month follow-up, 27.5% (n = 11) of patients achieved progression-free survival. The cutoff of TLR, which was related to the median value, did not affect disease control rate, progression-free survival, and overall survival in patients with Y-90 TARE. CONCLUSIONS: The TLR-based stratification may be a simple method, but our study did not show the usefulness in predicting prognosis in HCC patients with Y-90 TARE. Further studies with large number of patients are needed.

A Janus upconverting nanoplatform with biodegradability for glutathione depletion, near-infrared light induced photodynamic therapy and accelerated excretion.

The major limitations of photodynamic therapy (PDT) are the poor tissue penetration of excitation light and the neutralization of reactive oxygen species (ROS) generated by overexpressed glutathione (GSH) in cancer cells. Despite tremendous efforts to design nanoplatforms, PDT still suffers from unsatisfactory effects. Furthermore, the residual of nanomaterials in the body has restricted their clinical application. To address these issues, Janus nanocomposites containing an Yb/Er codoped NaYF4 upconverting nanocrystal head and a disulfide-bridged mesoporous organosilicon body (UCN/MON) with loaded chlorin e6 (Ce6) were designed. On one hand, the upconverting nanocrystal head can convert near-infrared (NIR) light into visible light to activate Ce6 to release ROS. On the other hand, the silica body can be degraded though a redox reaction with GSH, to not only improve the tumor selectivity of the photosensitizer by redox- and pH-triggered Ce6 release, but also diminish the concentration of GSH in cancer cells to reduce the depletion of ROS. Thereby, an enhanced PDT triggered by NIR irradiation was achieved. Furthermore, UCN/MONs showed a higher clearance rate after therapeutic actions than nonbiodegradable UCN/MSNs due to their biocompatibility. Taken together, this work revealed the potential of UCN/MONs for highly efficient and NIR-induced PDT, highlighting the prospects of UCN/MONs in the clinic.

The potential role of nanoyttria in alleviating oxidative stress biomarkers: Implications for Alzheimer's disease therapy.

Alzheimer's disease (AD) is a fatal neurodegenerative disease that requires immediate attention. Oxidative stress that leads to the generation of reactive oxygen species is a contributing factor to the disease progression by promoting synthesis and deposition of amyloid-ß, the main hallmark protein in AD. It has been previously demonstrated that nanoyttria possesses antioxidant properties and can alleviate cellular oxidative injury in various toxicity and disease models. This review proposed that nanoyttria could be used for the treatment of AD. In this paper, the evidence on the antioxidant potential of nanoyttria is presented and its prospects on AD therapy are discussed.

Activatable Photodynamic Therapy with Therapeutic Effect Prediction Based on a Self-correction Upconversion Nanoprobe.

Though emerging as a promising therapeutic approach for cancers, the crucial challenge for photodynamic therapy (PDT) is activatable phototoxicity for selective cancer cell destruction with low "off-target" damage and simultaneous therapeutic effect prediction. Here, we design an upconversion nanoprobe for intracellular cathepsin B (CaB)-responsive PDT with in situ self-corrected therapeutic effect prediction. The upconversion nanoprobe is composed of multishelled upconversion nanoparticles (UCNPs) NaYF4:Gd@NaYF4:Er,Yb@NaYF4:Nd,Yb, which covalently modified with an antenna molecule 800CW for UCNPs luminance enhancement under NIR irradiation, photosensitizer Rose Bengal (RB) for PDT, Cy3 for therapeutic effect prediction, and CaB substrate peptide labeled with a QSY7 quencher. The energy of UCNPs emission at 540 nm is transferred to Cy3/RB and eventually quenched by QSY7 via two continuous luminance resonance energy transfer processes from interior UCNPs to its surface-extended QSY7. The intracellular CaB specifically cleaves peptide to release QSY7, which correspondingly activates RB with reactive oxygen species (ROS) generation for PDT and recovers Cy3 luminance for CaB imaging. UCNPs emission at 540 nm remains unchanged during the peptide cleavage process, which is served as an internal standard for Cy3 luminance correction, and the fluorescence intensity ratio of Cy3 over UCNPs (FI583/FI540) is measured for self-corrected therapeutic effect prediction. The proposed self-corrected upconversion nanoprobe implies significant potential in precise tumor therapy.

Effect of 5α-reductase inhibitors on the efficiency of thulium:yttrium-aluminium-garnet (RevoLix®) vaporesection for treating benign prostatic hyperplasia.

Purpose: Preoperative use of 5α-reductase inhibitors (5ARIs) may cause fibrosis of the prostate tissue and reduce the efficiency of thulium laser surgery for treating benign prostate hyperplasia (BPH). Thus, we investigated the effects of preoperative 5ARI use in this setting. Materials and Methods: This retrospective study examined 184 patients who underwent thulium laser surgery for BPH during 2012-2017. Patients were grouped according to their 5ARI use in order to compare their preoperative and intraoperative characteristics and subsequent outcomes. Surgical efficiency was assessed using vaporesection efficiency. The total operation time, vaporesection time and prostate volume change were measured. Results: The 5ARI+ group included 83 patients (45.1%) and the 5ARI- group included 101 patients (54.9%). There were no significant differences in the two groups' preoperative characteristics, postoperative prostate size, thulium laser energy use, or prostate volume reduction rate. However, relative to the 5ARI- group, the 5ARI+ group had a significant shorter total operative time (65.0 min vs. 70.0 min, p=0.013) and a significantly shorter vaporesection time (48.0 min vs. 54.0 min, p=0.014), which resulted in significantly higher vaporesection efficiency in the 5ARI+ group (0.66 mL/min vs. 0.51 mL/min, p<0.001). Both groups exhibit significant improvements in their quality of life score and International Prostate Symptom Score during the 12-month follow-up. Conclusions: In contrast with our expectations, the preoperative use of 5ARI increased the efficiency of thulium laser surgery for BPH. Thus, it may not be necessary to stop 5ARI treatment before performing thulium laser surgery in this setting.

Long Term Follow-up of Intralesional Laser Photocoagulation for Head and Neck Lymphatic Malformations Using Neodymium-Yttrium-Aluminium-Garnet Laser.

BACKGROUND: Lymphatic malformations remain a challenge for patients and plastic surgeons. Promising results have been reported using intralesional laser photocoagulation (ILP) for treating vascular anomalies. BACKGROUND DATA: The objective of our study is to review the long-term results of a large series of lymphatic malformations in patients treated with ILP. MATERIALS AND METHODS: A retrospective review of 190 head and neck lymphatic malformations in patients were treated by ILP with an neodymium-yttrium-aluminum-garnet (Nd:YAG) laser (1064 nm) over a period of 20 years (January 1997-January 2016). Patients' ages ranged from 10 months to 12 years and 6 months (mean, 1 year and 11 months). The patient group consisted of 98 female and 92 male patients. RESULTS: Patients were treated with an Nd:YAG laser (Sharplan Inc, Allendale, New Jersey) delivered through a 600-µm optical fiber. Laser power was set at 7 to 15 W and delivered with a pulse duration of 7 to 15 seconds. All patients demonstrated improvement as judged by clinical assessment of the reduction in lesion size (range, 65%-100%; mean reduction, 85%). One hundred fifty-two (80%) patients had a more than 65% reduction of the volume in lymphatic malformations at 3 months after 1 treatment, and 171 (90%) patients had a more than 85% reduction of the volume after 2 treatments. Excellent results were seen in 19 (10%) patients after 3 treatments. Postoperative complications were related to photocoagulation that was delivered too extensively or superficially, with resultant ulceration, infection, induration, and scarring. CONCLUSIONS: Throughout the course of our long-term study, ILP using an Nd:YAG laser is an effective treatment modality for lymphatic malformations. Complications can be avoided if the potential for harm is kept in mind.

Management of a Laryngeal Venous Malformation With Nd:YAG Laser and Bleomycin Sclerotherapy.

Literature describing neodymium:yttrium-aluminum-garnet (Nd:YAG) photocoagulation and sclerotherapy for laryngeal venous malformations (VMs) is sparse. Here we present a case in which an extensive laryngeal VM in a 28-year-old female was managed through a combination of four serial Nd:YAG laser photocoagulation sessions and four bleomycin injections over the course of 2 years. The treatment plan resulted in resulted in noticeable lesion ablation, mucosalization, and significant improvement in symptoms. To our knowledge, this case is the first instance of bleomycin injection specifically into a laryngeal VM reported in the English medical literature. Laryngoscope, 130:2199-2201, 2020.

Comparison of the Neodymium-doped Yttrium Aluminum Garnet Capsulotomy Rate with Viscoimplantation and the Hydroimplantation Intraocular Lens Technique.

PURPOSE: To investigate the rate of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy in the hydroimplantation intraocular lens (IOL) technique. METHODS: This retrospective study was comprised of 6,192 eyes in 3,790 patients who underwent surgery from January 2013 to September 2017 and then were followed up for at least 1 year. The eyes of these patients were divided into two groups: either viscoimplantation or hydroimplantation. The follow-up examinations were carried out on the 1st day, 4th day, 1st month, and 3 months to 1 year postoperatively. The Nd:YAG capsulotomy rates were evaluated by the different IOL implantation techniques and IOL materials. RESULTS: The mean follow-up duration of the patients was in the viscoimplantation group 14.85 ± 2.43 and 15.05 ± 1.93 months in the hydroimplantation group. The Nd:YAG capsulotomy rate was significantly lower in the hydroimplantation group compared with the viscoimplantation group for the entire hydrophilic IOL model (p < 0.001). In addition, the Nd:YAG rate was lower in the hydroimplantation group that used a hydrophilic IOL than it was in the viscoimplantation group, which used a hydrophobic IOL. CONCLUSIONS: The hydroimplantation technique reduced the Nd:YAG capsulotomy rate.

Efficacy of using erbium, chromium-doped: Yttrium scandium gallium garnet laser-treated dentine in a dentine barrier test device.

OBJECTIVES: The aim of this study was to evaluate the efficacy of using erbium, chromium-doped:yttrium scandium gallium garnet (Er,Cr:YSGG) laser-treated dentine in a dentine barrier test device. MATERIALS AND METHODS: The test materials (G-Bond™ and Vitrebond™) were applied onto laser-treated or laser-untreated dentine discs. After 24 h of exposure with perfusion of the test chamber, cell survival was evaluated based on enzyme activity and compared to a nontoxic control material. The mean of the control was set to 100% viability. Data were analyzed using the one-way analysis of variance and the Tukey's honest significant difference tests. RESULTS: The responses of bovine pulp-derived cells after exposure to G-Bond and Vitrebond on Er,Cr:YSGG laser-treated and laser-untreated dentin were statistically different from negative control group (P < 0.05). CONCLUSION: Er,Cr:YSGG laser treatment was not successful enough in decreasing the cytotoxic effects of the dental materials. Different parameters of Er,Cr:YSGG laser or different laser types could be investigated as an alternative to minimizing the cytotoxic effects of dental materials.

Effect of Different Surface Treatments on Biaxial Flexural Strength of Yttria-stabilized Tetragonal Zirconia Polycrystal.

INTRODUCTION: Ceramics are widely applied in dentistry owing to their excellent mechanical and physical attributes. The most popular ceramics are Lava™, KaVo Everest, and Cercon. However, it is unclear whether or not a different surface treatment along with low-temperature aging and mechanical loading (ML) affects the physical properties of computer-aided design (CAD)/computer-aided manufacturing (CAM)-machined yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramic. AIM: The objective of this research was to assess the impact of various surface treatments as air-particle abrasion, ML, low-temperature degradation (LTD), and their cumulative effects on biaxial flexural properties of Y-TZP. MATERIALS AND METHODS: Totally, 50 specimens were fabricated by CAD-CAM machining from Cercon® and divided into five groups following different surface treatments as control (C), air-particle abrasion (Si), ML, LTD, and cumulative treatment (CT) group. Results were investigated by two-way analysis of variance (ANOVA) and Tukey honest significant difference (HSD) test. RESULTS: The highest biaxial flexural strength was observed in the Si group (950.2 ± 126.7 MPa), followed by the LTD group (861.3 ± 166.8 MPa), CT group (851.2 ± 126.5 MPa), and the least with ML (820 ± 110 MPa). A significant difference was observed in the two-way ANOVA test. X-ray diffraction (XRD) analysis showed that the control group consists of 100% tetragonal zirconia and the maximum amount of monoclinic phase was obtained after LTD. CONCLUSION: No negative effect on biaxial flexural strength was observed; indeed, it increases the biaxial strength. Hence, these surface treatments can be done in routine clinical practice to improve the performance of ceramic restoration.

Effect of laser peripheral iridotomy using argon and neodymium-YAG lasers on corneal endothelial cell density: 7-year longitudinal evaluation.

PURPOSE: To evaluate the changes in corneal endothelial cell density (ECD) over a 7-year period after laser peripheral iridotomy (LPI) using argon and neodymium-doped yttrium aluminum garnet (Nd:YAG) lasers. STUDY DESIGN: Retrospective case series. METHODS: Eyes that underwent prophylactic LPI using argon and Nd:YAG lasers were followed up for 7 years. Central corneal endothelial cells were observed by use of noncontact specular microscopy preoperatively and at 1 and 7 years postoperatively. Changes in ECD and the associations between preoperative ECD and the total energy of the Nd:YAG laser were evaluated. RESULTS: Fifty-one eyes of 51 patients were followed up for 7 years. The ECD significantly decreased after LPI (P < 0.049), and the reduction rate at 1 year after the surgery (1.69 ± 4.80%, 95% CI: 0.34%-3.04%) was significantly higher than the annual reduction rates after 1 year (0.17 ± 0.85%/y, P = 0.036, 95% CI: -0.07% to 0.41%). No association was found between the preoperative ECD and the total laser energy. CONCLUSIONS: Long-term evaluation indicated that the reduction in ECD after argon-Nd:YAG laser LPI was present but small during the initial year and was negligible after 1 year.

Development of a functionalized UV-emitting nanocomposite for the treatment of cancer using indirect photodynamic therapy.

BACKGROUND: Photodynamic therapy is a promising cancer therapy modality but its application for deep-seated tumor is mainly hindered by the shallow penetration of visible light. X-ray-mediated photodynamic therapy (PDT) has gained a major attention owing to the limitless penetration of X-rays. However, substantial outcomes have still not been achieved due to the low luminescence efficiency of scintillating nanoparticles and weak energy transfer to the photosensitizer. The present work describes the development of Y2.99Pr0.01Al5O12-based (YP) mesoporous silica coated nanoparticles, multifunctionalized with protoporphyrin IX (PpIX) and folic acid (YPMS@PpIX@FA) for potential application in targeted deep PDT. RESULTS: A YP nanophosphor core was synthesized using the sol-gel method to be used as X-ray energy transducer and was then covered with a mesoporous silica layer. The luminescence analysis indicated a good spectral overlap between the PpIX and nanoscintillator at the Soret as well as Q-band region. The comparison of the emission spectra with or without PpIX showed signs of energy transfer, a prerequisite for deep PDT. In vitro studies showed the preferential uptake of the nanocomposite in cancer cells expressing the folate receptorFolr1, validating the targeting efficiency. Direct activation of conjugated PpIX with UVA in vitro induced ROS production causing breast and prostate cancer cell death indicating that the PpIX retained its activity after conjugation to the nanocomposite. The in vivo toxicity analysis showed the good biocompatibility and non-immunogenic response of YPMS@PpIX@FA. CONCLUSION: Our results indicate that YPMS@PpIX@FA nanocomposites are promising candidates for X-ray-mediated PDT of deep-seated tumors. The design of these nanoparticles allows the functionalization with exchangeable targeting ligands thus offering versatility, in order to target various cancer cells, expressing different molecular targets on their surface.

Effect of surface treatments on repair with composite resin of a partially monoclinic phase transformed yttrium-stabilized tetragonal zirconia.

STATEMENT OF PROBLEM: Studies of composite resin repairs of yttrium-tetragonal zirconia polycrystal (Y-TZP) are usually performed in its tetragonal phase, but it may be partially transformed into a monoclinic phase in a clinical fracture. PURPOSE: The purpose of this in vitro study was to evaluate the effect of airborne-particle abrasion (APA) and a bonding agent on the shear bond strength (SBS) between a composite resin and hydrothermally aged Y-TZP. MATERIAL AND METHODS: Specimens (7.0×7.0×1.7 mm, N=112) of Y-TZP Lava were obtained, and 50% were aged in an autoclave at 134°C at 300 kPa for 8 hours. The surfaces were treated with APA 50-µm Al2O3 particles (ALU) or Rocatec Soft (30 µm) (ROC) followed by Clearfil SE Bond Primer (10-methacryloyloxydecyl dihydrogen phosphate [10-MDP]) plus Clearfil porcelain bond activator (3-methacryloxypropyl-trimethoxy silane [3-MPS]) (CLE) or RelyX Ceramic Primer plus a layer of RelyX U100 adhesive-resin cement (REL). Composite resin cylinders were built on the Y-TZP treated surfaces. After thermocycling (6000 cycles, 5°C and 55°C, 30-second dwell time), an SBS test was carried out (n=14). Data were analyzed by 3-way ANOVA and the Tukey honest significant differences test (α=.05). The failure mode was analyzed. RESULTS: The 3-way ANOVA was not significant for aging (P>.05), but the APA (P<.001), bonding agent (P<.001), and their interaction (P<.001) were significant. APA with ALU or ROC did not influence the SBS of the groups bonded with CLE, but the REL APA with ROC provided higher SBS. The failure mode was adhesive for all specimens. CONCLUSIONS: Adhesion was not different on monoclinic partially transformed Y-TZP. The APA with ROC followed by REL was the most effective treatment for repairing Y-TZP.

Wear Evaluation of Prosthetic Materials Opposing Themselves.

The purpose of the present in vitro study was to compare the two-body wear resistance of a type 3 gold alloy (Aurocast8), two lithium disilicate glass ceramics (IPS e.max CAD and IPS e.max Press), a heat-pressed feldspathic porcelain (Cerabien ZR Press), an yttria-stabilized tetragonal zirconia polycrystal ceramic (Katana Zirconia ML), and three heat-cured composite resins (Ceram.X Universal, Enamel Plus Function, and Enamel Plus HRi) opposing antagonistic cusps made out of the same restorative materials. Ten 6-mm-thick samples and 10 cusp-shaped abraders were manufactured with each test material (n=10) according to standard laboratory procedures. All sample/antagonist pairs made out of the same material were subjected to a two-body wear test in a dual-axis chewing simulator for up to 120,000 loading cycles. The total vertical wear (mm) and the total volumetric loss (mm3) for each sample/antagonist pair were calculated. Data were statistically analyzed using one-way analysis of variance tests. The total vertical wear for the gold alloy was not significantly different compared to Ceram.X Universal, Enamel Plus Function, IPS e.max CAD, and Cerabien ZR Press. Significantly increased wear values were observed for Enamel Plus HRi and IPS e.max Press. The lowest values for total vertical wear and volumetric loss were recorded on the monolithic zirconia.

Grinding With Diamond Burs and Hydrothermal Aging of a Y-TZP Material: Effect on the Material Surface Characteristics and Bacterial Adhesion.

The aim of this study was to evaluate the effect of grinding with diamond burs and low-temperature aging on the material surface characteristics and bacteria adhesion on a yttrium-stabilized tetragonal zirconia polycrystalline (Y-TZP) surface. Y-TZP specimens were made from presintered blocks, sintered as recommended by the manufacturer, and assigned into six groups according to two factors-grinding (three levels: as sintered, grinding with extra-fine diamond bur [25-µm grit], and grinding with coarse diamond bur [181-µm grit]) and hydrothermal aging-to promote low-temperature degradation (two levels: presence/absence). Phase transformation (X-ray diffractometer), surface roughness, micromorphological patterns (atomic force microscopy), and contact angle (goniometer) were analyzed. Bacterial adhesion (colony-forming units [CFU]/biofilm) was quantified using an in vitro polymicrobial biofilm model. Both the surface treatment and hydrothermal aging promoted an increase in m-phase content. Roughness values increased as a function of increasing bur grit sizes. Grinding with a coarse diamond bur resulted in significantly lower values of contact angle (p<0.05) when compared with the extra-fine and control groups, while there were no differences (p<0.05) after hydrothermal aging simulation. The CFU/biofilm results showed that neither the surface treatment nor hydrothermal aging simulation significantly affected the bacteria adherence (p>0.05). Grinding with diamond burs and hydrothermal aging modified the Y-TZP surface properties; however, these properties had no effect on the amount of bacteria adhesion on the material surface.