Evaluation of marginal and internal adaptation of veneers generated by the guided prosthetic tooth preparation system.

OBJECTIVE: This in vitro study aimed to assess and contrast the marginal and internal adaptation of all-ceramic prefabricated veneers manufactured via the FirstFit guided tooth preparation system against all-ceramic veneers produced using the chairside Computer-Aided Design/Computer Aided Manufacture (CAD/CAM) system following identical guided preparation protocols. MATERIALS AND METHODS: Two main groups were included, with 16 lithium disilicate veneers per group. Four typodonts were used for the test (FirstFit) and control CAD/CAM groups. Intraoral scans created master casts and preparation guides. Guides performed preparations on typodont teeth (two central incisors and two lateral incisors). Prepared teeth were scanned (CEREC Omnicam) to design and mill CAD/CAM veneers. Marginal gap thickness and cement space thickness were measured using light microscopy at four locations: marginal, cervical internal, middle internal, and incisal internal. RESULTS: No significant difference existed between groups for marginal adaptation (p = 0.058) or incisal internal adaptation (p = 0.076). The control group had significantly lower values for middle internal adaptation (p = 0.023) and cervical internal adaptation (p = 0.019). CONCLUSIONS: Guided preparation evaluation showed no significant differences in marginal or incisal internal adaptation. The CAD/CAM group had significantly lower middle and cervical internal adaptation values.

Biaxial flexural strength of various CAD-CAM glass-ceramic materials.

PURPOSE: To evaluate and compare the flexural strength of three CAD-CAM glass-ceramic materials and to investigate the effect of various surface treatments on their flexural strength. METHODS: 120 rectangular specimens were fabricated from three different types of CAD-CAM ceramic blocks and were divided into three groups: zirconia-reinforced lithium silicate (Celtra Duo, Group 1), leucite-reinforced glass-ceramic (IPS Empress CAD, Group 2), and lithium disilicate ceramic (IPS e.max CAD, Group 3). Dimensions of the specimens were standardized to 14.5x12.5 mm and 1.5 mm thickness. Specimens in each group were randomized into four subgroups. The first subgroup (NS) did not undergo any surface treatment; the second subgroup (P) underwent polishing only; the third subgroup (G) underwent glazing only; and the fourth subgroup (PG) underwent both polishing and glazing surface treatments. Biaxial flexural strength (FS) testing was performed until fracture occurred; FS was calculated in MPa. All analyses were performed using SPSS version 24. RESULTS: Group NS2 showed the lowest FS (89.34 ± 25.30 MPa). Group PG3 showed a significantly higher FS (365.38 ± 52.52 MPa) than Group P3 (268.15 ± 48.34). There was a statistically significant difference among the material groups for each surface treatment: IPS e.max CAD showed the highest FS, which was significantly greater than that of both Celtra Duo and IPS Empress CAD. The combination of polishing and glazing surface treatment resulted in significantly higher flexural strength than polishing alone for all three materials tested. For each material, no significant difference was found between the following surface treatments: control and polishing-only surface treatments; glazing-alone and the combination of polishing and glazing surface treatments. For each surface treatment, Celtra Duo showed significantly lower flexural strength than IPS e.max CAD. However, it displayed higher flexural strength than IPS Empress CAD, although the difference was only significant for glazing and the combination of polishing and glazing. CLINICAL SIGNIFICANCE: This study provides the clinician with an estimate of the flexural strength of glass-ceramic materials and shows how various surface treatments affect their strength.

Effect of acidic pH on surface roughness of esthetic dental materials.

STATEMENT OF PROBLEM: Exposure to gastric acid in patients with bulimia nervosa and gastroesophageal reflux disease (GERD) causes demineralization of hard tooth structures. This chemical attack also causes the degradation of dental ceramics, which results in increased surface roughness and reduced strength. However, studies comparing the effect of acidic pH on resin matrix ceramic with other computer-aided design and computer-aided manufacturing (CAD-CAM) esthetic materials are lacking. PURPOSE: The purpose of this in vitro study was to compare the surface roughness changes of different CAD-CAM restorative dental materials after exposure to acidic pH by using a 3D optical interferometer. MATERIAL AND METHODS: Five esthetic CAD-CAM block materials, a leucite glass-ceramic (IPS Empress CAD), a zirconia (BruxZir Solid Zirconia), a resin matrix ceramic (VITA Enamic), a lithium disilicate glass-ceramic (IPS e.max CAD), and a feldspathic porcelain (VITABLOCS Mark II CAD) were tested. Eighteen specimens were sectioned from CAD-CAM blocks into 2-mm-thick rectangular plates and immersed in 10 mL of 5% hydrochloric acid (HCl) with (pH=2) at 37 °C for 45 and 91 hours. The surface roughness average (Ra) of the specimens was measured by using a 3D optical interferometer before the storage period (baseline), after 45 hours, and after 91 hours of exposure to HCl. Statistical analyses were performed with the Kruskal-Wallis test and the post hoc Dunn test with Bonferroni correction (α=.05). RESULTS: Regarding the comparison of surface roughness changes at different periods of evaluation (baseline, 45 hours, 91 hours), there were no statistically significant differences for lithium disilicate (P=.063) or zirconia (P=.513). Leucite glass-ceramic, feldspathic porcelain, and the resin matrix ceramic demonstrated statistically significant differences (P<.001). For all tests that were statistically significant, greater surface roughness was found at the time point with the longer HCl exposure. Regarding the comparison of materials in terms of change in surface roughness between baseline to 45 hours and baseline to 91 hours, the Kruskal-Wallis test indicated a statistically significant difference among the materials in both cases (P<.001). Lithium disilicate and zirconia exhibited the least change in surface roughness among the 5 materials. CONCLUSIONS: Leucite glass-ceramic, feldspathic porcelain, and resin matrix ceramic showed statistically significant increases in surface roughness when they were exposed to simulated gastric acid for 45 and 91 hours. Lithium disilicate and zirconia showed no statistically significant change in surface roughness after exposure to HCl for 45 and 91 hours.

Effect of grinding and polishing on roughness and strength of zirconia.

STATEMENT OF PROBLEM: The clinical applications of high-translucency monolithic zirconia restorations have increased. Chairside and laboratory adjustments of these restorations are inevitable, which may lead to increased roughness and reduced strength. The influence of grinding and polishing on high-translucency zirconia has not been investigated. PURPOSE: The purpose of this in vitro study was to compare the roughness averages (Ra) of ground and polished zirconia and investigate whether roughness influenced strength after aging. MATERIAL AND METHODS: High-translucency zirconia disks were milled, sintered, and glazed according to the manufacturer's recommendations. Specimens were randomized to 4 equal groups. Group G received only grinding; groups GPB and GPK received grinding and polishing with different polishing systems; and group C was the (unground) control group. All specimens were subjected to hydrothermal aging in an autoclave at 134°C at 200 kPa for 3 hours. Roughness average was measured using a 3-dimensional (3D) optical interferometer at baseline (Ra1), after grinding and polishing (Ra2), and after aging (Ra3). A biaxial flexural strength test was performed at a rate of 0.5 mm/min. Statistical analyses were performed using commercial software (α=.05). RESULTS: Group G showed a significantly higher mean value of Ra3 (1.96 ±0.32 µm) than polished and glazed groups (P<.001), which showed no statistically significant difference among them (GPB, 1.12 ±0.31 µm; GPK, 0.88 ±0.31 µm; C: 0.87 ±0.25 µm) (P>.05). Compared with baseline, the roughness of groups G and GPB increased significantly after surface treatments and after aging, whereas aging did not significantly influence the roughness of groups GPK or C. Group G showed the lowest mean value of biaxial flexural strength (879.01 ±157.99 MPa), and the highest value was achieved by group C (962.40 ±113.84 MPa); no statistically significant differences were found among groups (P>.05). Additionally, no significant correlation was detected between the Ra and flexural strength of zirconia. CONCLUSIONS: Grinding increased the roughness of zirconia restorations, whereas proper polishing resulted in smoothness comparable with glazed surfaces. The results provide no evidence that grinding and polishing affect the flexural strength of zirconia after aging.

Micro-CT Evaluation of Ceramic Inlays: Comparison of the Marginal and Internal Fit of Five and Three Axis CAM Systems with a Heat Press Technique.

OBJECTIVES: To evaluate the marginal and internal adaptation of CAD/CAM lithium-disilicate inlay restorations fabricated by two milling systems (Five and Three-axis), and a traditional heat-press technique. METHODS: Fifteen premolar teeth with an MOD cavity preparation were fabricated. Lithium-disilicate inlay restorations were obtained by three fabrication techniques and fitted to their dies (n = 15/gp) as follows: Group-1, three-axis milling system, Group-2, five-axis milling system, Group-3, conventional heat-press technique. Gaps were evaluated by X-ray microtomography. Marginal gap (MG), occlusal-marginal gap (OMG), proximal-marginal gap (PMG), gingival-marginal gap (GMG), absolute marginal discrepancy (AMD), axial-internal gap (AIG), and occlusal-internal gap (OIG) were evaluated at 120 different points per inlay. Data were analyzed using repeated measures ANOVA. Pairwise comparisons were conducted for post-hoc testes and the Bonferroni correction was used to adjust for multiple comparisons (α = 0.007). RESULTS: The heat-press group demonstrated significantly smaller mean-values amongst all outcomes compared with CAD/CAM groups except for GMG, where there was no statistically significant difference between groups in the ANOVA (p = 0.042). Within the CAD/CAM groups, the five-axis group showed significantly lower OMG mean-value compared with the three-axis group p < 0.001, and lower AIG mean-value compared with the three-axis group p < 0.001. There was no significant difference between the five-axis and the three-axis groups' AMD, MG, PMG, and OIG locations. CONCLUSION: Different fabrication techniques affected the marginal and internal adaptation of ceramic inlay restorations. The heat-press group showed the best marginal and internal adaptation results; however, in every group, all samples were within the clinically acceptable MG limit (100 µm). CLINICAL SIGNIFICANCE: The marginal fit and internal adaptation of inlay ceramic restorations fabricated by a five-axis milling system have not been tested or compared with those fabricated by three-axis machines and the conventional heat-press method. The preferred method of inlay fabrication, whether in the lab or chair side, may be influenced by the results of this study and could affect future clinical decision-making. (J Esthet Restor Dent 29:49-58, 2017).

An In Vitro Comparison of the Marginal Adaptation Accuracy of CAD/CAM Restorations Using Different Impression Systems.

PURPOSE: To compare the marginal adaptation of 3-unit zirconia fixed dental prostheses (FDPs) obtained from intraoral digital scanners (Lava True Definition, Cadent iTero), scanning of a conventional silicone impression, and the resulting master cast with an extraoral scanner (3Shape lab scanner). MATERIALS AND METHODS: One reference model was fabricated from intact, non-carious, unrestored human mandibular left first premolar and first molar teeth (teeth #19 and 21), prepared for a three-unit all-ceramic FDP. Impressions of the reference model were obtained using four impression systems (n = 10), group 1 (PVS impression scan), group 2 (stone cast scan), group 3 (Cadent iTero), and group 4 (Lava True Defintion). Then the three-unit zirconia FDPs were milled. Marginal adaptation of the zirconia FDPs was evaluated using an optical comparator at four points on each abutment. The mean (SD) was reported for each group. One-way ANOVA was used to assess the statistical significance of the results, with post hoc tests conducted via Tukey's HSD. p < 0.05 was considered statistically significant. All analyses were done using SPSS 22.0. RESULTS: The mean (SD) marginal gaps for the recorded data from highest to lowest were silicone impression scans 81.4 µm (6.8), Cadent iTero scan 62.4 µm (5.0), master cast scan 50.2 µm (6.1), and Lava True definition scan 26.6 µm (4.7). One-way ANOVA revealed significant differences (p < 0.001) in the mean marginal gap among the groups. The Tukey's HSD tests demonstrated that the differences between all groups (silicone impression scan, master cast scan, Lava True definition scan, iTero Cadent scan) were statistically significant (all p < 0.001). On the basis of the criterion of 120 µm as the limit of clinical acceptance, all marginal discrepancy values of all groups were clinically acceptable. CONCLUSIONS: Within the confines of this in vitro study, it can be concluded that the marginal gap of all impression techniques was within the acceptable clinical limit (120 µm). Group 4 (Lava True Defintion) showed the lowest average gap among all groups followed by group 2 (stone cast scan), group 3 (Cadent iTero), and group 1 (PVS impression scan); these differences were statistically significant.

A three-dimensional analysis of the effect of atopy on face shape.

Three-dimensional (3D) imaging technology has been widely used to analyse facial morphology and has revealed an influence of some medical conditions on craniofacial growth and morphology. The aim of the study is to investigate whether craniofacial morphology is different in atopic Caucasian children compared with controls. Study design included observational longitudinal cohort study. Atopy was diagnosed via skin-prick tests performed at 7.5 years of age. The cohort was followed to 15 years of age as part of the Avon Longitudinal Study of Parents and Children (ALSPAC). A total of 734 atopic and 2829 controls were identified. 3D laser surface facial scans were obtained at 15 years of age. Twenty-one reproducible facial landmarks (x, y, z co-ordinates) were identified on each facial scan. Inter-landmark distances and average facial shells for atopic and non-atopic children were compared with explore differences in face shape between the groups. Both total anterior face height (pg-g, pg-men) and mid-face height (Is-men, sn-men, n-sn) were longer (0.6 and 0.4mm respectively) in atopic children when compared with non-atopic children. No facial differences were detected in the transverse and antero-posterior relationships. Small but statistically significant differences were detected in the total and mid-face height between atopic and non-atopic children. No differences were detected in the transverse and antero-posterior relationships.

The influence of asthma on face shape: a three-dimensional study.

Respiratory activity may have an influence on craniofacial development and interact with genetic and environmental factors. It has been suggested that certain medical conditions such as asthma have an influence on face shape. The aim of the study is to investigate whether facial shape is different in individuals diagnosed as having asthma compared with controls. Study design included observational longitudinal cohort study. Asthma was defined as reported wheezing diagnosed at age 7 years and 6 months. The cohort was followed to 15 years of age as part of the Avon Longitudinal Study of Parents and Children. A total of 418 asthmatics and 3010 controls were identified. Three-dimensional laser surface facial scans were obtained. Twenty-one reproducible facial landmarks (x, y, z co-ordinates) were identified. Average facial shells were created for asthmatic and non-asthmatic males and females to explore surface differences. The inter-ala distance was 0.4mm wider (95% CI) and mid-face height was 0.4mm (95% CI) shorter in asthmatic females when compared with non-asthmatic females. No facial differences were detected in male subjects. Small but statistically significant differences were detected in mid-face height and inter-ala width between asthmatic and non-asthmatic females. No differences were detected in males. The lack of detection of any facial differences in males may be explained by significant facial variation as a result of achieving different stages of facial growth due to pubertal changes, which may mask any underlying condition effect.

An in vitro comparison of the shear bond strengths of two different gingiva-colored materials bonded to commercially pure titanium and acrylic artificial teeth.

PURPOSE: The purpose of this study was to compare shear bond strengths between two different gingiva-colored materials bonded to titanium alloy discs and acrylic resin artificial teeth. MATERIALS AND METHODS: For the first part of this study, 30 titanium alloy disc specimens were embedded in autopolymerizing resin. These discs were then divided randomly into two groups: Heat Cure (HT(1) ) and Pink Composite (CT(1) ). The discs were sandblasted with 100 µm aluminum oxide particles. For the HT(1) group using silicone molds, a wax-up was performed. After the wax removal step, heat-cured acrylic resin was applied and processed according to the manufacturer's recommendations. For the CT(1) group using silicone molds, metal primer II and gum opaque were applied and light cured; pink composite was then applied and light cured. For the second part of the study, 30 artificial resin first molar teeth were completely embedded in autopolymerizing resin. Teeth were then divided randomly into two groups: Heat Cure (HT(2) ) and Pink Composite (CT(2) ). For the HT(2) group using silicone molds, wax-up was performed. Specimens were then transferred to be processed in the heat-cured acrylic resin according to the manufacturer's recommendations. For the CT(2) group using silicone molds, composite primer followed by pink composite were applied and light cured. Shear bond tests were performed using an Instron 3345 universal testing machine. The shear load at the point of failure was recorded in Newtons. The force was calculated in MPa by calculating the failure load divided by the surface area. Two independent-samples t-tests were performed. A significance level of p < 0.05 was used for comparison. RESULTS: This study revealed that the difference in the shear bond strengths of two different gingiva-colored materials bonded to titanium discs was statistically significant (p = 0.012). The difference in the shear bond strengths of two different gingival-colored materials bonded to acrylic teeth was statistically significant (p < 0.001). CONCLUSION: In this in vitro study, heat-cured acrylic resins exhibited higher bonding strengths when bonded to titanium discs or acrylic artificial teeth in comparison to pink composite resins.

Antibacterial Activity and Shear Bond Strength of Orthodontic Adhesive Containing Various Sizes of Chitosan Nanoparticles: An In Vitro Study.

INTRODUCTION: White spot lesions are common after orthodontic treatment. Chitosan nanoparticles (CS-NPs) have emerged as promising antibacterial agents that inhibit the growth of Streptococcus mutans. The aim of the study was to investigate the nano-effect of adhesives containing CS-NPs on S. mutans and their effects on shear bond strength. MATERIALS AND METHODS: The inhibitory effects of two sizes of CS-NPs were assessed using the disc agar diffusion method. Four wells were created in the petri dishes, and each was inoculated with broth (negative control), chlorhexidine (positive control), CS-NPs (20 nm), or CS-NPs (131 nm). An Instron machine was used to evaluate shear bond strength by allocating 24 teeth into three groups, and all measurements were recorded in megapascals. Caries progression was assessed using the International Caries Detection and Assessment System and surface profilometry. Statistical analysis was performed using IBM SPSS Statistics for Windows, Version 27.0 (Released 2020; IBM Corp., Armonk, New York, United States) for a one-way ANOVA followed by Tukey's multiple comparison test. RESULTS: Disc agar diffusion showed a reduction in S. mutans in the CS-NP group compared to the control (p < 0.001), with no statistical significance between the sizes of 20 and 131 nm (p = 0.95). Regarding shear bond strength, no differences were recorded when adhesive-containing CS-NPs and the control were compared (p = 0.44). Additionally, no differences were found within the CS-NP groups (p = 0.91). Caries assessments showed excellent agreement, as indicated by a weighted kappa. Profilometry readings showed higher surface roughness in the control than in the CS-NP groups (p < 0.001), with no statistically significant difference between the CS-NP groups (p = 0.72). CONCLUSION: CS-NPs of both sizes tested had similar antibacterial effects. In addition, the incorporation of CS-NPs did not affect shear bond strength.

Lung Ultrasound and Caval Indices to Assess Volume Status in Maintenance Hemodialysis Patients.

Background: Volume overload is common in end stage kidney disease (ESKD) and dialysis patients. Hence, the need for objective tools to detect such volume excess. Point of care ultrasound (POCUS) is a goal-directed, bedside examination to answer such a specific diagnostic question. Methods: One hundred Iraqi adult hemodialysis patients were recruited from February 1 to May 31, 2022. Primary clinical, dialysis data, and prescriptions were recorded. A nephrologist performed a POCUS examination after the last dialysis session of the week. In addition, an ultrasound examination of the chest was performed to detect B-lines and pleural effusion. Caval parameters included inferior vena cava (IVC) diameter and collapsibility index. Results: The mean age of the study group was 51.48 ± 14.6 years, with 53% males. The mean interdialytic weight gain was 2.74 ± 1.15 Kg. Lower limb edema and pleural effusion were present in 33% and 27%, respectively. Forty-seven percent of patients had >3 B-lines on lung ultrasound with a range of 12. Forty-three percent of patients had an IVC diameter of >2 cm, and 93% had <50% IVC collapsibility. In total, 97% of patients had evidence of excess volume by ultrasound criteria. IVC collapsibility index was the most prevalent sign of excess volume (93%). Patients without lower limb edema and pleural effusion had positive B-lines in 38.8% and 38.3%, an IVC diameter >2 cm in 46.2% and 38.3%, and IVC collapsibility <50% in 89.5% and 95.8% respectively. Conclusion: Iraqi maintenance hemodialysis patients are volume overloaded, which warrants proper intervention for detection and dialysis management. POCUS is a useful and easily performed technique to assess the volume status.

Perception and satisfaction of nephrology education and training in Iraq.

BACKGROUND: Interest in training in nephrology is declining around the world. This is a particularly worrisome issue for future nephrology practice with the aging population and the increasing number of patients with kidney disease. We wished to understand the perception and measure the satisfaction of Iraqi medical interns regarding nephrology and explore factors affecting career decisions towards becoming a specialist nephrologist. METHODS: A web-based authors-constructed survey consisting of a Likert-type scale questionnaire to assess perception and satisfaction was used. It comprised multiple-choice yes/no/maybe questions and addressed the willingness to pursue a career in nephrology. Iraqi medical interns in their final 2 years of training, 2021-2022, were assessed. RESULTS: One hundred and twenty internal medicine Iraqi fellows participated in the survey (response rate 84.2%). Sixty-eight fellows (74%) described nephrology as a complex science. Acid-base and electrolytes disorders and transplantation were the most challenging topics, followed by glomerular diseases. Twenty-one fellows (23%) were satisfied with the quality of training and nephrology education during their medical school, residency and internship. In addition, 14% stated that they would pursue a future career in nephrology. The most selected barrier (34%) against choosing nephrology was a fellow's perception of the patient's complexity and the potentially futile outcome. CONCLUSION: The majority (76%) of Iraqi medical interns are currently not satisfied with nephrology training and education. One in seven would pursue a future career in nephrology. New targeted innovative approaches are urgently needed for the various grades of trainees to highlight the benefits of nephrology as a career.

Effects of Oral Sodium Bicarbonate Supplementation on Protein Metabolism and Inflammation in Iraqi Hemodialysis Patients: An Open-Label Randomized Controlled Trial.

Background: The effect of correcting metabolic acidosis on protein metabolism in hemodialysis patients is controversial. Objectives: To study the effects of oral sodium bicarbonate on protein metabolism and markers of inflammation in acidotic hemodialysis patients. Patients and Methods. An open-label randomized controlled trial was conducted at a single center. Sixty-six clinically stable adult hemodialysis patients were recruited with an average predialysis serum bicarbonate level of <22 mmol/l and a dialysate bicarbonate concentration of 35 mmol/l. Forty-nine participants have completed the study. Oral sodium bicarbonate tablets of 500 mg were given daily in the intervention group (n = 25) for 12 weeks versus the standard of care in the control group (n = 24). Outcomes compared intervention versus nonintervention in both groups at equivalent time points (0 and 3 months). The clinical data, anthropometry, dialysis adequacy, albumin, normalized protein catabolism rate, blood gas analysis, and bicarbonate were recorded at 0 and 3 months. In addition, muscle mass and handgrip strength were measured. Finally, IL-6 as a marker of inflammation was measured at randomization and three months. Results: Serum bicarbonate and pH increased significantly from 17.57 ± 3.34 mmol/L to 20.69 ± 2.54 mmol/L and from 7.26 ± 0.06 to 7.34 ± 0.04, respectively (p < 0.0001). Serum albumin was significantly higher in the intervention group at three months than in the control group, 4.11 ± 0.45 vs. 3.79 ± 0.47 (p value 0.011). Serum potassium significantly decreased in the intervention group at three months compared to the control group, 5.00 ± 0.43 mEq/l vs. 5.33 ± 0.63 mEq/l (p value 0.03). Muscle strength expressed as handgrip has improved significantly in the intervention group at three months compared to the control group, 45.01 ± 19.19 vs. 33.93 ± 15.06 (p value 0.03). The IL-6 values were less in the intervention group at 3 months with a p value of 0.01. The interdialytic weight of the intervention group at three months was 2.42 ± 0.64 compared to the 2.20 ± 1.14 control group, but this did not reach statistical significance (p value of 0.4). The composite of (albumin + nPCR) at three months was achieved in 59.18% of the intervention group compared to 14.28% with a p value of 0.01. Conclusions: Correcting metabolic acidosis in hemodialysis patients improved serum albumin and nPCR without hypokalemia or significant interdialytic weight gain. This was particularly evident in patients with minimal inflammation with low IL-6 values.

The influence of different convergence angles and resin cements on the retention of zirconia copings.

PURPOSE: This in vitro study aimed to determine the ability of three resin cements to retain zirconia copings under two clinically simulated conditions. MATERIALS AND METHODS: Extracted human molars (72) were collected, cleaned, and divided into two groups. All teeth were prepared with a 15° total convergence angle for group 1 and a 30° total convergence angle for group 2, a flat occlusal surface, and approximately 4-mm axial length. Each group was divided by surface area into three subgroups (n = 12). All zirconia copings were abraded with 50-µm Al(2)O(3), then cemented using Panavia F 2.0 (PAN-1) (PAN-2) Rely X Unicem (RXU-1) (RXU-2), and Clearfil SA (CSA-1) (CSA-2). After cementation, the copings were thermocycled for 5000 cycles between 5°C and 55°C with a 15-second dwell time. Then the copings were subjected to dislodgment force in a universal testing machine at 0.5 mm/min. The force of removal was recorded, and the dislodgement stress was calculated. A Kruskal-Wallis test (nonparametric ANOVA) was used to analyze the data (α= 0.05), and the nature of failure was also recorded. RESULTS: The mean (SD) coping removal stresses (MPa) were as follows: PAN-1: 6.0 (1.3), CSA-1: 4.8 (1.4), RXU-1: 5.5 (2.3), PAN-2: 2.8 (1.1), CSA-2: 3.0 (1.25), and RXU-2: 2.6 (1.2). The Kruskal-Wallis test was significant. Mann-Whitney pairwise comparisons of the subgroups were significant (p < 0.05) for the comparisons between subgroups of group 1 and group 2. Mode of failure was mixed, with cement remaining principally on the tooth for PAN. For CSA and RXU, mode of failure was mixed with cement remaining principally on the zirconia copings. CONCLUSIONS: Retention values of zirconia copings with three different resin cements were not significantly different. Retention of zirconia copings cemented on the teeth with adequate resistance and retention form was higher than that cemented on teeth lacking these forms. The cement remained mostly on the tooth with the adhesive resin cement with a dentin bonding system. The cement remained mostly on the coping with the self-adhesive resin cement.

Living Kidney Donation: Glomerular Filtration Rate-Based Donor Selection Criteria.

Despite different guidelines and recommendations for evaluating the renal function of living kidney donors, there is still no consensus about the best approach. It is uncertain whether to have measured glomerular filtration rate, estimated it, or both. The absolute value, body surface area-dependent, and age-specified estimated glomerular filtration rates have not been consistent across different populations and practices. The increasing demand for donors has mandated clear selection criteria for glomerular filtration rate. Thus, the next big question is how low should the glomerular filtration be? Indeed, a low level would preclude the misclassification of donors and mitigate future donor risks of chronic kidney disease. The recent consensus on removing factors on race and ethnicity in the estimated glomerular filtration rate equations added a new perspective to the concept of donor assessment of glomerular filtration rate. Furthermore, the increasing use of point of care devices to assess creatinine and estimated glomerular filtration rate will be a paradigm shift in the practice of nephrology. These challenges and updates make glomerular filtration rate-based donor selection criteria an always timely topic in living kidney donation.

Young Transplant Professionals in the Middle East Society for Organ Transplantation Region: Challenges and Opportunities.

The power of youth represents the versatility of the Middle East, which has the largest number of youths among other world regions. Therefore, when addressing the future of organ transplantation in this region, the perspectives of young transplant professionals would be invaluable. Organ donation and transplantation in the Middle East face many challenges. These challenges, which would be transferred to young professionals pursuing a career in transplantation, are related to transplant education, training, and the health system itself. Young transplant professionals are seeking a platform that will bring the wisdom of leaders and the energy of youth transplant professionals together. This platform would focus on increasing recruitment and engagement of young physicians and surgeons and decreasing the hurdles mentioned above. A team of young professionals from the Middle East Society for Organ Transplantation countries hopes to bring their different perspectives into fruitful actions. Online education, career development, basic science research, and others are potential goals to be tackled. However, achieving this could not be possible without mutual collaborations with other young colleague teams from other transplant societies. Indeed, these actions can improve transplant science globally and in the MESOT region.

Relapsing De Novo Membranous Nephropathy.

Allograft membranous glomerulopathy can be a recurrent or de novo disease. Both instead have different underlying immune pathophysiology and disease pattern. While the introduction of ANTI-PLAR2 and THS7A brought new insights into the management of Immune/primary MN, the treatment of de novo MN is not clear. Relapsing de novo MN in a kidney transplant was rarely reported. Here, we present a case of relapsing de novo MN without evidence of rejection and a gratifying response to rituximab.

Adherence to Immunosuppressive Medication in Iraqi Kidney Transplant Recipients During the First Year of Transplant. A Single-Center Experience.

OBJECTIVES: Our objective was to measure adherence to immunosuppressive medications among Iraqi renal transplant patients at a single center. MATERIALS AND METHODS: This cross-sectional study was conducted from January to November 2020 in the outpatient unit of the Nephrology and Renal Transplantation Center in Baghdad's Medical City. Seventy-five adult Iraqi renal transplant recipients were recruited. An Arabic version of the Basel Assessment of Adherence to Immunosuppressive Medications (BAASIS) scale was used to evaluate adherence. RESULTS: The study included 75 adult renal transplant recipients (51 men/24 women) with a mean age of 39.44 ± 12.06 years. The mean time posttransplant was 8.11 ± 3.12 months. In our patient group, 65.33% reported total adherence and 34.6% did not adhere to one (25.3%) or more (9.3%) drug. We observed a statistically significant association between nonadherence and complications (P = .015, chi-square test). Four patients had biopsy-proven acute rejection, and all 4 patients were noncompliant with medications. Binary logistic regression model P values for employment, time after transplant, and complications were .06, .06, and .08, respectively. CONCLUSIONS: There was a high rate of nonadherence among our sample of Iraqi renal transplant recipients in the first year posttransplant. Time after transplant and transplant complications were related to nonadherence. More extensive multicenter studies are needed to define the actual rate of adherence to immune suppression in Iraq.

Knowledge and Attitude of People With or Without a Medical Education Regarding Organ Donation and Transplant: A Sample From the City of Baghdad.

OBJECTIVES: Organ donation is the driving force for transplant. Awareness about donation and transplant is invaluable for improved transplant services in any country. Our objective was to assess the knowledge and attitude toward organ donation and transplant among medically educated adult Iraqis versus adult Iraqis who were not medically educated, in Baghdad, Iraq. MATERIALS AND METHODS: For this study, we recruited 400 Iraqi residents of Baghdad city from December 1, 2018, to March 1, 2019. We used an interviewer-adm-inistered questionnaire to survey 200 health care professionals and 200 adults who lacked medical education, and then we analyzed the responses from the 2 groups. RESULTS: The study included 165 males and 235 females (mean age 33.73 ± 10.38 years). Most participants (60%) were aware of organ donation, and a health care provider was the main source of their knowledge. Only 11.25% were aware of Iraqi legislation that permits donation after brain death. Nearly 50% of the participants volunteered to be living donors, and 229/400 (57.25%%) volunteered to donate after death. About 50% accepted the idea of organ donation as an act to save life, whomever the donor. The most important barrier was the fear of future risks to health after living donation and body disfigurement after death. There was a statistically significant difference in the knowledge and attitude scores between the 2 groups. From the study sample, 46.5% accepted the concept of incenting living donors or families of deceased donors. CONCLUSIONS: Iraqi people are moderately informed about organ donation and transplant. Medically educated people demonstrated an attitude of greater acceptance. Religion and social beliefs were not barriers to organ donation in the study sample. Regulated governmental application of incentive programs may be a useful strategy at present.