Laparoscopic versus open repair for peptic ulcer perforation: a systematic review, meta-analysis and trial sequential analysis of randomised controlled trials. Time to conclude!

INTRODUCTION: The aim of this study was to investigate comparative outcomes of laparoscopic and open repair for peptic ulcer perforation (PUP). METHODS: A PRISMA-compliant systematic review with a PROSPERO-registered protocol (registration number CRD42024529286) was conducted. All randomised controlled trials (RCTs) involving PUP patients managed by laparoscopic or open repair were identified and their risk of bias assessed. Outcome syntheses for perioperative mortality and morbidities, need for reoperation, procedure time and length of hospital stay were conducted using random-effects modelling to calculate risk ratios (RR) or mean difference (MD) with 95% confidence intervals (CI). FINDINGS: Nine RCTs met the inclusion criteria, enrolling 670 patients of whom 317 were randomised to receive laparoscopic surgery and 353 were managed with open surgery. Laparoscopic repair of PUP significantly reduced mortality (RR 0.37, p = 0.03), total complications (RR 0.57, p = 0.0009), ileus (RR 0.43, p = 0.04), wound complications (RR 0.36, p < 0.0001) and length of hospital stay (MD -2.37, p = 0.0003) compared with the open approach. There were no significant differences in rate of postoperative leak (RR 2.00, 95% CI 0.74-5.41, p = 0.17), abdominal collection (RR 1.19, 95% CI 0.46-3.07, p = 0.72), sepsis (RR 1.17, 95% CI 0.39-3.52, p = 0.65), respiratory complications (RR 0.68, 95% CI 0.32-1.46, p = 0.32), reoperation (RR 1.74, 95% CI 0.57-5.30, p = 0.33) and operating time (MD 15.31, 95% CI -4.86 to 35.47, p = 0.14) between the two groups. CONCLUSIONS: Laparoscopic repair of PUP is associated with significantly lower mortality and morbidity and shorter length of stay compared with the open approach. The laparoscopic approach should be the management of choice subject to the existence of laparoscopic expertise.

Effect of COVID-19 Pandemic on Admission Pattern to Pediatric Surgery Division at King Fahad University Hospital and Subsequent Quality of Presentation in Cases: A Comparative Study and Single-Center Experience.

The coronavirus disease 2019 (COVID-19) pandemic has affected healthcare systems worldwide, with mandatory quarantine and isolation measures being implemented to curb the spread of the virus. These measures have potentially led to delayed or complicated presentations of non-COVID-19 cases, including pediatric surgical cases. This study aims to evaluate pediatric surgical admission patterns, analyze the incidence of surgical diagnoses, and assess the severity of presentation during the COVID-19 period compared to the pre-COVID-19 period. This retrospective observational study was conducted at a university hospital in the eastern region of Saudi Arabia to assess the effect of the pandemic on pediatric surgery admissions patterns and severity of presentation during the COVID-19 period (March 2, 2020, to March 1, 2022) and pre-COVID-19 period (March 1, 2018, to March 1, 2020). Of the 903 pediatric surgical admissions, 366 (40.5%) presented during the COVID-19 period. The admission rate per month decreased by 6.9 during COVID-19 compared to pre-COVID-19 (mean [SD]: 21.5 [9.3] vs. 14.6 [8.2], p = 0.01). The most common admission diagnoses were appendicitis (17.5%) and inguinal hernia (15.8%). There was a 15% increase in the percentage of emergency admissions (54.4% vs. 47.3%, p = 0.037) during COVID-19 compared to pre-COVID-19. Of note, the percentage of patients admitted with acute appendicitis increased by 35.9% (20.8% vs. 15.3%, p = 0.03). Furthermore, the emergency admissions for patients with inguinal hernia doubled (26.6% vs. 12.7%, p = 0.035). No significant difference in ICU admissions, hospital length of stay, and routine discharge were observed. In conclusion, the COVID-19 pandemic correlated with a significant decrease in overall admissions and an increase in emergency admissions, including those for appendicitis and inguinal hernia. The increase in complicated conditions was not significant. There was no significant difference in ICU admissions and hospital length of stay. Future studies involving multiple centers are necessary to validate these findings.

Long-Term Bonding Efficacy of CAD/CAM Hybrid Restorative Materials and Universal Adhesives.

OBJECTIVES: In-office and lab milled prostheses are the staple for indirect restorations. It is therefore critical to determine their long-term bonding durability. METHODS: CAD/ CAM blocks of two classes of restorative materials: 1) a nano-ceramic reinforced polymer matrix (NCPM) and, 2) a polymer-infiltrated ceramic network (PICN) were bonded using four different universal adhesives (UA) and silane systems. A lithium disilicate glassceramic (LDS) was used as a reference. The blocks were bisected and bonded with different UA/resin-cement pairs. Bonded blocks were then cut into 1.0x1.0x12.0 mm bar specimens for microtensile bond testing. Half the bars were subjected to bond strength testing immediately and the other half after aging by 50,000 thermal cycles between 5°C and 55°C. ANOVA and post-hoc tests were used to compare mean bond strength among groups. RESULTS: NCPM presented consistently high bond strength regardless of bonding techniques, while the bond strength of PICN and LDS were lower when bonded with UA relative to traditional silanes. The more hydrophilic UA produced higher bond strengths. DISCUSSION: Glass-ceramics exhibited lower bond strength with UA than the conventional etch-rinse-silane techniques. However, UAs preserved bonding interface in the long-term. SIGNIFICANCE: NCPM displayed superior bond strength relative to PICN and LDS regardless of the type of adhesives and bonding techniques.

Personality traits and pre-treatment beliefs and cognitions predicting patient adherence to continuous positive airway pressure: A systematic review.

Adherence to Continuous Positive Airway Pressure (CPAP) for obstructive sleep apnoea (OSA) can be improved by behavioural interventions which modify patients' beliefs and cognitions about OSA, CPAP, and themselves. We have conducted the first systematic review of the literature on beliefs and cognitions held before starting treatment, and personality (which influences the former) that predict the decision to purchase or start CPAP, or CPAP adherence one month or more after CPAP initiation. A systematic search and screen of articles identified 21 eligible publications from an initial 1317. Quality assessment performed using an adapted Newcastle-Ottawa Scale demonstrated that 13 (62%) studies were poor quality and only seven (33%) were high quality. Eighteen factors, such as self-efficacy (confidence) in using CPAP and value placed on health predicted CPAP adherence; however, for only six (33%), utility as an intervention target is known, from calculation of individual predictive power. Studies did not use new behavioural frameworks effective at explaining adherence behaviours, nor did they interview patients to collect in-depth data on barriers and facilitators of CPAP use. Future studies cannot have these limitations if high quality evidence is to be generated for intervention development, which is currently sparse as highlighted by this review.

Patient Satisfaction and Accuracy of Partial Denture Frameworks Fabricated using Conventional and Digital Techniques.

This case report compares a conventional and a digital workflow for manufacturing metal frameworks for maxillary and mandibular removable partial dentures (RPDs). Two sets of maxillary and mandible RPDs were produced. The metal framework of one set of RPDs was produced conventionally using the lost wax casting technique. Intraoralscanning and computer-aided designing (CAD) were used to fabricate the metal frameworks of the other set of RPDs using direct metal laser sintering (DMLS) technology. The accuracy of fit of the two sets of RPDs was evaluated after 3 months using replica models. Patient satisfaction was assessed. Two years later, the fit accuracy of the DMLS prosthesis and patient satisfaction were re-evaluated. The accuracy of fit in the maxillary RPD with the DLMS manufactured metal framework showed better results in all areas except areas of rests (457 vs. 421 µm) and the major connector (850 vs. 512 µm). The mandibular RPD with DLMS manufactured metal framework showed only in the areas of the reciprocal arm and major connector better fit accuracy compared to the conventional RPD. The patient satisfaction with the DLMS manufactured RPDs was rated equally to the conventional one. The use of digital technologies in manufacturing RPDs seems promising regarding accuracy and patient satisfaction.

Demographic and clinical correlates of suicidal ideation in individuals with at-risk mental state (ARMS): A study from Pakistan.

BACKGROUND: Suicide is a major public health concern and one of the leading causes of mortality worldwide. People with an at-risk-mental-state (ARMS) for psychosis are more vulnerable to psychiatric co-morbidity and suicide, however, there are limited data from low-middle-income countries. The present study aimed to identify the prevalence of depressive symptoms and suicidal ideation along with sociodemographic and clinical correlates of suicidal ideation in individuals with ARMS from Pakistan. METHOD: Participants between the age of 16 and 35 years who met the criteria for ARMS based on the Comprehensive Assessment of At-Risk Mental State (CAARMS), were recruited from the community, general practitioner clinics and psychiatric units across Pakistan (n = 326). Montgomery and Asberg Depression Rating Scale (MADRS) and Social-Occupational-Functional-Assessment-Scale (SOFAS) were administered to participants. RESULTS: The prevalence of depressive symptoms and suicidal thoughts in the sample at baseline were 91.1% (n = 297) and 61.0% (n = 199), respectively. There were significant mean differences between groups (mean difference [95% CI]; p-value) without suicidal ideation and with suicidal ideation on measures of MADRS (-5.47 [-7.14, -3.81]; p < .001), CAARMS non-bizarre ideas (-0.29 [-0.47, -0.11]; p = .002) and perceptual abnormalities (-0.23 [-0.41, -0.04]; p = .015). CONCLUSION: These findings indicate that suicidal ideation and depressive symptoms are highly prevalent in individuals with ARMS in Pakistan. Given the pivotal developmental stages that ARMS presents, and the poor outcomes associated with co-morbid depression, there is an urgent need to prioritize the development of low-cost and scalable evidence-based interventions to address psychiatric comorbidity and suicidality in the ARMS population in Pakistan.

Evaluation of Clinical Periodontal Parameters of Abutment Teeth Supporting Distal-Extension Base Removable Partial Dentures: A Cross-sectional Study.

To assess the clinical periodontal status of abutment teeth in regards of different design components of distal-extension removable partial dentures. Subjects (N=100) with acrylic or cobalt-chromium distal-extension removable partial dentures were enrolled and their periodontal parameters plaque and gingival indices [PI, GI], probing depths [PD], clinical attachment loss [CAL] and a mobility index [MI] evaluated. Denture base type, major connector, occlusal rests position, design of direct retainers, retention, stability and denture wearing habits were further evaluated. Acrylic RPDs were associated with higher mean±SE PI [1.70±0.74], GI [1.76±0.55], PD scores [2.47±1.02 mm] and CAL values [4.46±2.11 mm] compared to CO-CR RPDs [p⟨0.05]. For abutments, the PI [1.6±0.83], GI [1.72±0.57], PD [2.32±1.03] and CAL [4.26±2.08] were higher than their non-abutments counterparts [p⟨0.05]. CAL scores were found to be significantly higher for mandibular abutments compared to maxillary ones [P=0.002]. The highest PI [1.83±1.10] and GI [2.00±0.00] scores were associated with lingual bars and horse-shoe connectors, respectively. Full palatal coverage and lingual plates were associated with the highest PD [2.80±0.48] and CAL [4.70±0.37] scores. Acrylic RPDs, type of major connector, wrought wire clasps and distal occlusal rests may be considered as risk factors for periodontal disease progression in distal-extension removable partial denture wearers.

Diagnostic performance using obesity and lipid-related indices and atherogenic index of plasma to predict metabolic syndrome in the adult sudanese population.

Background: Simple and accurate clinical indicators to detect metabolic abnormalities might be helpful for early management and lowering the risk of future consequences like cardiovascular disease and type 2 diabetes mellitus. Aim: The visceral adiposity index (VAI), lipid accumulation product (LAP), and atherogenic index of plasma (AIP) have been proposed as reliable, straightforward clinical markers and indications of metabolic syndrome (MetS). This study aimed to see how well these obesity and lipid-related indicators will predict MetS in adult Sudanese patients. Subjects and Methods: This community hospital-based case-control study included 420 middle-aged people (154 men and 266 women). Anthropometric measurements, weight (kilogram), height (meters), and waist circumference (WC) were evaluated, and the body mass index (BMI) and waist-to-height ratio (WHtR) were calculated. Fasting blood samples were collected for glycated hemoglobin (HbA1c) and lipid profile assessment. VAI, LAP, and AIP were calculated. Results: Significantly higher means of BMI, WC, WHtR, HbA1c, triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglycerides/high-density lipoprotein cholesterol (TG/HDL-C) ratio, LAP, VAI, AIP, and significantly decrease in high-density lipoprotein cholesterol (HDL-C) were seen among MetS when compared with non-MetS group. LAP had a significant proportion with BMI, WC, WHtR, TG, TG/HDL-C, VAI, and AIP, and it is inversely related to HDL-C in the MetS group. On ROC analysis, LAP had the largest operating characteristic curves (AUC) for both gender 0.970 (0.948-0.993) for men and 0.964 (0.945-0.982) for women, followed by WC, and VAI, while BMI showed the lowest AUCs for men and women. In multiple regression analyses, AIP values increased significantly with LDL-C, DBP, HbA1c, LAP, and VAI. Conclusion: The LAP was considerably higher in middle-aged people with MetS in both gender and was considered the best diagnostic performance.

Culturally adapted psychosocial interventions (CaPSI) for early psychosis in a low-resource setting: study protocol for a large multi-center RCT.

BACKGROUND: Psychosis treatment guidelines recommend cognitive behaviour therapy (CBT) and family intervention (FI), for all patients with first episode psychosis (FEP), though guidance borrows heavily from literature in adults from high income countries. To our knowledge, there are few randomized controlled trials (RCTs) examining the comparative effect of these commonly endorsed psychosocial interventions in individuals with early psychosis from high-income countries and no such trials from low and middle-income countries (LMICs). The present study aims to confirm the clinical-efficacy and cost-effectiveness of delivering culturally adapted CBT (CaCBT) and culturally adapted FI (CulFI) to individuals with FEP in Pakistan. METHOD: A multi-centre, three-arm RCT of CaCBT, CulFI, and treatment as usual (TAU) for individuals with FEP (n = 390), recruited from major centres across Pakistan. Reducing overall symptoms of FEP will be the primary outcome. Additional aims will include improving patient and carer outcomes and estimating the economic impact of delivering culturally appropriate psychosocial interventions in low-resource settings. This trial will assess the clinical-efficacy and cost-effectiveness of CaCBT and CulFI compared with TAU in improving patient (positive and negative symptoms of psychosis, general psychopathology, depressive symptoms, quality of life, cognition, general functioning, and insight) and carer related outcomes (carer experience, wellbeing, illness attitudes and symptoms of depression and anxiety). CONCLUSIONS: A successful trial may inform the rapid scale up of these interventions not only in Pakistan but other low-resource settings, to improve clinical outcomes, social and occupational functioning, and quality of life in South Asian and other minority groups with FEP. TRIAL REGISTRATION: NCT05814913.

Comparative Evaluation of Apically Extruded Debris During Root Canal Preparation Using Three Different File Systems Applied Under 2.5% Sodium Hypochlorite or 2% CHX Irrigation.

The chemomechanical cleaning of the root canal system is performed using manual and rotary files. This study aimed to compare the effect of ProTaper, Reciproc and HyFlex rotary files considering 2.5% sodium hypochlorite and 2% chlorhexidine (CHX) as irrigating solutions on apical extrusion of intracanal debris. Single-canal mandibular premolars (N=165) were evaluated. The teeth were divided into 6 experimental groups (N=25) for root canal instrumentation using 3 file systems, (Reciproc, HyFlex and ProTaper) and two irrigation solutions, namely 2.5% sodium hypochlorite or 2% CHX. Fifteen teeth were also assigned into three control groups (n=5) with saline as irrigation solution. Eppendorf tubes were weighed and the teeth were placed inside. The canals were instrumented and the tubes weighed to determine the dry weight of extruded debris. Data were analyzed using one-way ANOVA and Bonferroni test (α=0.05). The mean amount of extruded debris using the sodium hypochlorite solution was significantly higher than other irrigating solutions (p⟨0.001). The mean amount of extruded debris using the Reciproc file system was significantly higher compared to ProTaper and HyFlex (p⟨0.001). The use of the sodium hypochlorite solution, single-file systems and reciprocal movement are associated with higher debris extrusion and might be associated with higher risk of postoperative pain.

Effect of Thickness and Translucency on Color Change and Masking Ability of Ceramic Materials used for Laminate Veneers.

This study evaluated the effect of the thickness and translucency of lithium disilicatebased glass ceramics on resin composite substrates on color change and masking effect. Laminate veneers were fabricated using IPS e.max CAD (A1) blocks with two different light transmittance values (High translucent [HT], Low translucent [LT]). Slices of two different thicknesses (0.3 mm, 0.5 mm) were obtained (n=10) and laminate veneers were cemented on the resin composite substrates of two different shades (A2, A3.5). The color change (ΔE values) was evaluated with the CIELab color system using a spectrophotometer, while the masking effect was calculated. The data were analyzed using independent-samples t-test and two-way analysis of variance. The ceramic thickness and translucency had a significant effect on final color and masking. When HT was used, and the laminate veneer thickness decreased (0.3 mm), the masking effect in ΔE values were lower (p⟨0.05). The ΔE values (⟩3.7) were clinically unacceptable. With the increase in thickness, translucency of porcelain laminate veneers decreases showing better color masking ability. Veneer thickness seems to be more effective on the restoration's masking ability than the shade of the substrate and translucency. Cinically, in case a 0.5-mm or thinner laminate veneer is planned, tooth color, resin cement and ceramic type should be considered.

Oxygen-Sensing Chemiluminescent Iridium(III) 1,2-Dioxetanes: Unusual Coordination and Activity.

Next generation chemiluminescent iridium 1,2-dioxetane complexes have been developed which consist of the Schaap's 1,2-dioxetane scaffold directly attached to the metal center. This was achieved by synthetically modifying the scaffold precursor with a phenylpyridine moiety, which can act as a ligand. Reaction of this scaffold ligand with the iridium dimer [Ir(BTP)2(µ-Cl)]2 (BTP = 2-(benzo[b]thiophen-2-yl)pyridine) yielded isomers which depict ligation through either the cyclometalating carbon or, interestingly, the sulfur atom of one BTP ligand. Their corresponding 1,2-dioxetanes display chemiluminescent responses in buffered solutions, exhibiting a single, red-shifted peak at 600 nm. This triplet emission was effectively quenched by oxygen, yielding in vitro Stern-Volmer constants of 0.1 and 0.009 mbar-1 for the carbon-bound and sulfur compound, respectively. Lastly, the sulfur-bound dioxetane was further utilized for oxygen sensing in muscle tissue of living mice and xenograft models of tumor hypoxia, depicting the ability of the probe chemiluminescence to penetrate biological tissue (total flux ~ 106 p/s).

Evaluation of New Alkasite Based Restorative Material for Restoring Non- Carious Cervical Lesions- Randomized Controlled Clinical Trial.

Two different restoration materials, an alkasite-based resin composite and a resinmodified glass ionomer cement were used to assess restoration of non-carious cervical dental lesions. This split mouth randomized controlled trial included 40 patients. After randomization both sides of the dental arch were restored with either an alkasite-based (Cention N, Ivoclar Vivadent) or a resin-modified glass ionomer cement (Voco GmbH) restoration. The placed fillings were evaluated by blinded additional operators 1, 6 months and 1 year after to the USPHS criteria (retention, marginal integrity and discoloration, anatomical form and secondary caries). Data were analyzed using Kendall's Coefficient of Concordance test and Chi-square tests using SPSS software (SPSS Inc., Version 20) (P=0.05). As for retention and anatomic form both materials performed similar after one month. However, the retention and anatomic form for alkasite based restorative Cention showed significantly better results after 6 months (p=0.013/p=0.003) and one year (p=0.026/p=0.008). The resin modified glass ionomer restoration showed higher discoloration after 6 months (p=0.025) and one year (p=0.018), while Cention performed better regarding marginal integrity at all time intervals. No secondary caries occurred. Alkasite based restorative materials displayed superior technical, mechanical and aesthetical performance in a follow-up period of one year and can therefore be recommended as an alternative to resin-modified glass ionomer cements.

Immediate and Late Repair of Microhybrid Resin Composites: Effect of Silane Coupling Agent, Universal Adhesives and Photo Polymerization.

This study investigated the effect of silane coupling agent and universal adhesive application on repair bond strength of resin-based composite after bur grinding. Microhybrid resin composite (Charisma Smart) blocks (N=80; 8x8x4 mm3) were prepared, aged (37°C; 1 month), roughened, etched and randomly divided into two groups. Silane was applied to half of the groups (Porcelain Primer, Bisco), before one of the following universal primers/adhesives was applied: a) Scotchbond Universal (3M), b) All-Bond Universal (Bisco), c) G-Premio Bond (GC), and d) Clearfil SE Bond (Kuraray). In each adhesive group half of the group was photo-polymerized. The blocks were repaired with the same size resin composite and segmented into beams. Half of the beams were subjected to micro-tensile bond test (1 mm/min), while the other half was aged (37°C; 6 months) prior to testing. Failure modes were analyzed using Scanning Electron Microscopy (SEM). Data were analyzed using repeated measures of ANOVA, Tukey's post-hoc, and paired t-tests (alpha=0.05). The silane application did not affect the repair bond strength regardless of photo-polymerization of the adhesive resin. The repair bond strength decreased significantly after 6 months when adhesive resin was not photopolymerized (p⟨0.05). Photo-polymerizing universal adhesives might ensure higher repair bond strength and its maintenance after aging.

Energy Transfer Chemiluminescent Spiroadamantane 1,2-Dioxetane Probes for Bioanalyte Detection and Imaging.

Chemiluminescence imaging of bioanalytes using spiroadamantane 1,2-dioxetanes has gained significant attention due to improved signal-to-noise ratios and imaging depth compared to excitation-based probes, as well as their modifiable scaffolds that offer analyte-specific responses and tunable emissive properties. Among several strategies employed to amplify signals under aqueous conditions and to shift the emission into the bio-relevant red region, energy transfer to an adjacent fluorophore is a popular and effective method. This Minireview highlights spiroadamantane 1,2-dioxetane-based probes that operate via an energy transfer mechanism to detect bioanalytes both in vitro and in vivo. Probes that display both non-covalent and covalent interactions with fluorophores, as well as their applications in imaging specific analytes will be discussed.

Dark Dynamic Therapy: Photosensitization without Light Excitation Using Chemiluminescence Resonance Energy Transfer in a Dioxetane-Erythrosin B Conjugate.

Reactive oxygen species (e.g., singlet oxygen) are the primary cytotoxic agents used in the clinically approved technique photodynamic therapy (PDT). Although singlet oxygen has high potential to effectively kill tumor cells, its production via light excitation of a photosensitizer has been limited by the penetration depth and delivery of light in tissue. To produce singlet oxygen without light excitation, we describe the use of Schaap's chemiluminescent scaffold comprising an adamantylidene-dioxetane motif. Functionalizing this scaffold with a photosensitizer, Erythrosin B, resulted in spontaneous chemiluminescence resonance energy transfer (CRET) leading to the production of singlet oxygen. We show that this compound is cell permeable and that the singlet oxygen produced via CRET is remarkably efficient in killing cancer cells at low micromolar concentrations. Moreover, we demonstrate that protection of the phenol on the chemiluminescent scaffold with a nitroreductase-responsive trigger group allows for cancer-selective dark dynamic cell death. Here, we present the concept of dark dynamic therapy using a small cell-permeable molecule capable of producing the effects of PDT in cells, without light.

Chemiluminescent spiroadamantane-1,2-dioxetanes: Recent advances in molecular imaging and biomarker detection.

Triggered chemiluminescence emission of spiroadamantane-1,2-dioxetanes to detect bioanalytes has fueled the emerging popularity of chemiluminescence imaging in live animals and cells. Recently, a structural evolution of the dioxetane scaffolds towards near-infrared emitters has been observed, and efforts have been made for quantitative and semi-quantitative detection of a wide range of analytes. In this review, we summarize the current chemiluminescence imaging developments of spiroadamantane-1,2-dioxetanes. Specifically, we look at examples which depict whole animal or cellular chemiluminescence imaging of small molecules and enzymes, as well as those that portray their potential diagnostic and therapeutic abilities, with an emphasis on analyte quantification and experimental parameters.

Evaluating the Bond Strength of a Polymer Infiltrated Ceramic Network to Zirconia Using the Crossbeam Push-Off Method.

Porcelains and glass-ceramics have been used to produce CAD-milled veneers and crowns for zirconia copings and implant-abutments. This study evaluated the bondstrength of a polymer-infiltrated-ceramic-network to zirconia using two adhesive cement systems: Panavia 21 and Multilink Automix. Lithium disilicate and feldspathic porcelain were also tested as reference CAD-On materials. Long beams (3x6x40 mm³) of zirconia and short beams (3x6x15 mm³) of the CAD-On materials were prepared. Zirconia and each CAD-On material were bonded in a crossbeam arrangement and subjected to a modified tensile bond-strength test. Half of the samples in each group (n=10) were tested 5 days after bonding (baseline) and the remaining (n=10) underwent aging (50,000 thermocycles at 5°C and 55°C) prior to bond-strength testing. The effects of material, cement, and aging on the tensile bond-strength were tested using a three-way ANOVA. The reference lithium disilicate/Multilink system showed no significant differences in bond strength compared to polymer-infiltrated-ceramic-network and porcelain. The long-term retention of polymer-infiltrated-ceramic-network was not statistically different compared to the baseline values and the two reference materials. With comparable bond strength between all materials, polymer-infiltrated-ceramic-network is the favorable choice for CAD-On to zirconia copings and implant-abutments due to its superior resistance to fatigue fracture relative to porcelain.

Chemiluminescent 1,2-Dioxetane Iridium Complexes for Near-Infrared Oxygen Sensing.

Chemiluminescent iridium-based sensors which demonstrate oxygen dependent responses have been developed. The molecular probes, named IrCL-1, IrCL-2 and IrCL-3 consist of oxygen-sensitive iridium complexes attached to a spiroadamantane 1,2 dioxetane and operate via energy transfer from the chemiexcited benzoate to the corresponding iridium(III) complex. Complexing the iridium(III) center with π-extended ligands results in emission in the biologically relevant, near-infrared (NIR) region. All probes demonstrate varying oxygen tolerance, with IrCL-1 being the most oxygen sensitive. These probes have been further utilized for in vitro ratiometric imaging of oxygen, as well as for intraperitoneal, intramuscular and intratumoral imaging in live mice. To our knowledge, these are the first iridium-based chemiluminescent probes that have been employed for in vitro ratiometric oxygen sensing, and for in vivo tumor imaging.