The effect of speed sintering on the optical properties and microstructure of multi-layered cubic zirconia.

PURPOSE: Speed sintering was introduced to fabricate time-efficient chairside restorations, however, its influence on the microstructure and optical properties of zirconia is still unclear. This study investigated the influence of speed sintering on the microstructure and optical properties of ultra-translucent multi-layered cubic zirconia. MATERIALS AND METHODS: Ultra-translucent cubic zirconia (Katana™ UTML; Kuraray Noritake Dental Inc., Aichi, Japan) was cut into a total of 80 specimens, twenty within each layer of the blank. The specimens were divided into 2 groups: speed and conventional sintering. The translucency parameter, opalescence, chromaticity, and color difference were recorded using a spectrophotometer. Scanning electron microscope images were used for crystallographic analysis. One-way ANOVA and Tukey's post-hoc test (p < 0.05) were used for data analysis. RESULTS: Speed sintering significantly reduced the translucency and opalescence compared to conventional sintering excluding the opalescence of the dentin layer. Chromaticity significantly decreased with speed sintering in less chromatic layers and significantly increased in more chromatic layers. Mean color change ranged between 0.65 and 1.25 across different layers. Mean crystal size decreased with speed sintering. CONCLUSIONS: With speed sintering, translucency, and opalescence decrease while chromaticity increases in the more chromatic layers. Additionally, no clinically perceptible color change was found compared to conventional sintering.

Impact of tumor size on the outcomes of hepatic resection for hepatocellular carcinoma: a retrospective study.

BACKGROUND: To evaluate the impact of tumor size on the perioperative and long-term outcomes of liver resection for hepatocellular carcinoma (HCC). METHODS: We reviewed the patients' data who underwent liver resection for HCC between November 2009 and 2019. Patients were divided into 3 groups according to the tumor size. Group I: HCC < 5 cm, Group II: HCC between 5 to 10 cm, and Group III: HCC ≥ 10 cm in size. RESULTS: Three hundred fifteen patients were included in the current study. Lower platelets count was noted Groups I and II. Higher serum alpha-feto protein was noted in Group III. Higher incidence of multiple tumors, macroscopic portal vein invasion, nearby organ invasion and presence of porta-hepatis lymph nodes were found in Group III. More major liver resections were performed in Group III. Longer operation time, more blood loss and more transfusion requirements were found in Group III. Longer hospital stay and more postoperative morbidities were noted in Group III, especially posthepatectomy liver failure, and respiratory complications. The median follow-up duration was 17 months (7-110 months). Mortality occurred in 100 patients (31.7%) and recurrence occurred in 147 patients (46.7%). There were no significant differences between the groups regarding recurrence free survival (Log Rank, p = 0.089) but not for overall survival (Log Rank, p = 0.001). CONCLUSION: HCC size is not a contraindication for liver resection. With proper selection, safe techniques and standardized care, adequate outcomes could be achieved.

A comparative analysis of the passivity of fit of complete arch implant-supported frameworks fabricated using different acquisition techniques.

STATEMENT OF PROBLEM: The accuracy of intraoral scanners (IOSs) in recording edentulous jaws has improved recently. However, improvement in accuracy does not necessarily imply the clinical validity of the scans, and limited information is available regarding the manufacture of passively fitting prostheses. PURPOSE: The purpose of this in vitro study was to analyze the passivity of complete arch screw-retained frameworks fabricated using different acquisition techniques. MATERIAL AND METHODS: A 3-dimensional maxillary edentulous model to receive all-on-4 screw-retained frameworks was prototyped. Eighteen polymethylmethacrylate (PMMA) frameworks were fabricated with a 5-axis milling machine and divided into 3 groups according to the acquisition technique (n=6): scanned by using an IOS (CEREC Primescan; Dentsply Sirona), scanned with the aid of an auxiliary device by using the same IOS, and by using a conventional impression and then scanning the stone cast with an extraoral scanner (EOS). The passivity of fit of the frameworks was tested with the 1-screw test, the terminal screw of the framework assembly was tightened on the multiunit abutment (MUA), and the vertical marginal gap (µm) was measured at the other 3 framework-to-abutment interfaces by using a digital microscope at ×40 magnification. A modification to the 1-screw test was analyzed by tightening all screws and then unscrewing all except 1 of the anterior abutments. Data were explored for normality by using the theoretical quantile-quantile (Q-Q) plots and the Shapiro-Wilk test of normality. The Friedman test compared data between the different acquisition techniques; the tightening methods and locations (buccal and palatal) were used as the block variable. The post hoc Dunn test was used when the Friedman test was significant. The Kruksal-Wallis test compared the data from the 2 groups of the tightening methods and the 2 location groups. The aligned rank transformation (ART) ANOVA test was used for the interaction effects among the 3 variables. A multiway ANOVA was applied to the ranked data. (α=.05 for all tests). RESULTS: Significant differences were found among all groups (P<.001). Regarding the passivity of fit, the mean vertical marginal gap was 50 µm for frameworks fabricated from an intraoral scan with the aid of an auxiliary device, 62 µm for frameworks fabricated by using an IOS, and 140 µm for frameworks fabricated by using an EOS. No significant difference was found among all groups regarding the tightening method (P=.355) or location measured (P=.175). CONCLUSIONS: Digital scanning with the aid of an auxiliary device resulted in the best fit; however, digital approaches with or without the auxiliary device resulted in a more accurate fit with a smaller marginal gap than with the conventional impression.

Effect of different preparation designs of minimally invasive occlusal onlays on the accuracy of different intraoral scanners: An in vitro study.

PURPOSE: The aim of this in vitro study was to assess and compare three different preparation designs of minimally invasive occlusal onlays on the trueness and precision of three different intraoral scanners under two different scanning conditions. MATERIALS AND METHODS: Three maxillary premolars were prepared in three different designs and divided accordingly into three groups, Group 1: Anatomical (n = 60), Group 2: Flat (n = 60), and Group 3: Ferrule (n = 60). The samples were then further divided into subgroups according to scanners as subgroup A: Medit i500 (n = 20), subgroup B: 3Shape TRIOS 4 (n = 20), and subgroup C: Cerec Primescan (n = 20). Last, the samples were further divided according to scanning conditions: Division i: As prepared (n = 10) and Division ii: Sprayed - scan spray (n = 10). An industrial 3D scanner was used to obtain the reference STL files. Accuracy was assessed in terms of trueness and precision and recorded in terms of root mean square in micrometers. Numerical data were explored for normality using Shapiro-Wilk test and were analyzed using 3-way ANOVA followed by Tukey's post hoc test. RESULTS: Regarding trueness, 3-way ANOVA showed that all tested variables had a significant effect on trueness. Significant interactions were found between the different variables (p < 0.001). For preparation design the highest value was found in ferrule preparation (27.88 ± 7.11), followed by flat preparation (22.99 ± 7.56), while the lowest value was found in anatomical preparation (18.83 ± 5.71) (p < 0.001). For scanner type, the highest value was found in Primescan (25.36 ± 10.66), followed by TRIOS 4 (22.75 ± 5.98), while the lowest value was found in Medit i500 (21.59 ± 5.03) (p < 0.001). As for the scanning condition, sprayed samples (26.54 ± 8.24) had a significantly higher value than non-sprayed samples (19.93 ± 5.53) (p < 0.001). Regarding precision, both preparation design and scanner type had a significant effect on precision. Scanning conditions had no significant effect. There was a significant interaction between the three tested variables (p = 0.012). CONCLUSIONS: Anatomical preparation of minimally invasive occlusal onlays produced the most accurate scans. Within the tested preparation designs, Medit i500 and 3Shape TRIOS 4 have better trueness than Cerec Primescan. Cerec Primescan is more precise than 3Shape TRIOS 4 and Medit i500 Scan spray application causes a higher deviation in the trueness of the tested intraoral scanners while it does not affect their precision.

Feasibility and outcomes of living-donor liver transplantation utilizing the right hemi-liver graft with portal vein anatomical variations.

PURPOSE: Portal vein (PV) reconstruction is a key factor for successful living-donor liver transplantation (LDLT). Anatomical variations of right PV (RPV) are encountered among potential donors. METHODS: To evaluate a single center experience of reconstruction techniques for the right hemi-liver grafts with PV variations during the period between May 2004 and 2022. RESULTS: A total of 915 recipients underwent LDLT, among them 52 (5.8%) had RPV anatomical variations. Type II PV was found in 7 cases (13.5%), which were reconstructed by direct venoplasty. Type III PV was found in 27 cases (51.9%). They were reconstructed by direct venoplasty in 2 cases (3.8%), Y graft interposition in 2 cases (3.8%), and in situ double PV anastomoses in 23 cases (44.2%). Type IV PV was found in 18 cases (34.6%) and was reconstructed by Y graft interposition in 9 cases (17.3%), and in situ double PV anastomoses in 9 cases (17.3%). Early right posterior PV stenosis occurred in 2 recipients (3.8%). Early PV thrombosis occurred in 3 recipients (5.8%). The median follow-up duration was 54.5 months (4 - 185). The 1-, 3-, and 5-years survival rates were 91.9%, 86%, and 81.2%, respectively. Late PV stenosis occurred in 2 recipients (3.8%) and was managed conservatively. CONCLUSION: Utilization of potential living donors with RPV anatomic variations may help to expand the donor pool. We found that direct venoplasty and in situ dual PV anastomoses techniques were safe, feasible, and associated with successful outcomes.

Predictive factors of postendoscopic retrograde cholangiopancreatography pancreatitis for biliary complications in living-donor liver transplantation recipients.

OBJECTIVES: Endoscopic retrograde cholangiopancreatography (ERCP) has shown great safety and efficacy in the management of post-living-donor liver transplantation (LDLT) biliary complications. Pancreatitis is the most commonest and the most feared complication after ERCP. METHODS: We reviewed the data of liver transplant recipients who underwent ERCP for biliary complications after LDLT between 2011 and 2022. RESULTS: In total 63 patients underwent ERCP after LDLT. They were targeted to 134 set of ERCP. Pancreatitis occurred in 52 sets (38.8%). We subclassified the patients into two groups, without pancreatitis: 31 patients (49.2%) and with pancreatitis 32 patients (50.8%). A higher incidence of pancreatitis was noticed with the first ERCP set (P = 0.04). Biliary strictures were more noted in the pancreatitis group (P = 0.025). Difficult cannulation requiring precut was more observed in the pancreatitis group (P = 0.007). Also, more frequent sphincterotomy was observed in the pancreatitis group (P = 0.003). Longer hospital stay, more fever, abdominal pain and vomiting were noted in the pancreatitis group (P = 0.001). Higher post-ERCP serum amylase (P = 0.001) and creatinine (P = 0.021), while lower serum calcium (P = 0.21) were noticed in the pancreatitis group. On multivariate analysis, preoperative diabetes, number of biliary anastomoses (single/multiple) and difficult cannulation requiring precut were significant predictors of post-ERCP pancreatitis. CONCLUSION: Patient-related risk factors and bedside procedure-related risk factors play an essential role in the development of pancreatitis after ERCP for LDLT recipients. Endoscopists should be mindful by those high-risk patients during ERCP to apply appropriate techniques to prevent the development of this serious complication.

Fracture Resistance of Custom Lithium Disilicate Implant Restorations with Two Fabrication Techniques and Two Designs.

PURPOSE: To compare the fracture resistance of a press-on ceramic custom implant restoration with pressed and cemented restorations. MATERIALS AND METHODS: Thirty-two (32) lithium disilicate (IPS e.max Press) custom hybrid abutment restorations were fabricated. The restorations were divided into two groups (n = 16) according to the construction technique: the commercial control group (C) and the press-on group (P). For the control group, lithium disilicate restorations were pressed and cemented on titanium bases. For the press-on group, lithium disilicate pressable ceramic (IPS e.max Press) was pressed on the titanium bases with injection molding. Each group was further divided according to the restoration design, either screw- or cement-retained, into two subgroups of eight specimens each. Specimens of C group were divided into screw-retained (cemented hybrid abutment crown, CHAC) or cement-retained (cemented hybrid abutment, CHA). Specimens of the P group were also divided into screw-retained (pressed hybrid abutment crown, PHAC) and cement-retained (pressed hybrid abutment, PHA). The specimens were subjected to static loading until failure with a universal testing machine. Two-way analysis of variance (ANOVA) was used to assess the effect of different techniques and designs on the fracture resistance of the samples (P < .05), followed by one-way ANOVA and Tukey honest significant difference (HSD) test (α = .05). RESULTS: C group showed higher mean fracture resistance (812.443 ± 129.14 N) than P group (596.71 ± 108.83 N), and the difference was statistically significant (P < .05). Regarding restoration design, HA groups showed higher mean fracture resistance (742.621 ± 153.82 N) than HAC (666.53 ± 163.07 N) groups with no statistically significant difference. CHA showed the highest mean fracture resistance (817.65 ± 161.76 N), while PHAC showed the lowest mean fracture resistance values (525.83 ± 47.29 N). CONCLUSION: The commercial cemented lithium disilicate restorations showed higher fracture resistance than the press-on restorations, although both showed a maximum load capacity that was greater than physiologic incisal force in the anterior region, and both hybrid abutments and hybrid abutment crowns were equally efficient in withstanding occlusal loading forces.

Effect of Different Preparation Depths for an Inlay-Retained Fixed Partial Denture on the Accuracy of Different Intraoral Scanners: An In Vitro Study.

PURPOSE: The aim was to evaluate the effect of different preparation depths for inlay-retained fixed partial dentures on the accuracy of intraoral scanners. MATERIALS AND METHODS: Tooth preparations for two inlay-retained fixed partial dentures were done and divided according to depth of the preparation. Group A: 2 mm pulpal floor depth, 3 mm gingival floor depth and Group B: 3 mm pulpal floor depth, 4mm gingival floor depth. The CEREC Omnicam 4.4.4, Omnicam 4.6.2. Trios3 and Medit i500 intraoral scanners were used in this study. Tooth preparations were scanned by each scanner 10 times. The STL files obtained from the intraoral scanners were compared to the reference models (trueness) and within each test group (precision) using a 3D comparison software. Data were then statistically analyzed. RESULTS: Regarding trueness, two-way ANOVA revealed significant differences between the different types of scanners (p < 0.001) (Omnicam 4.4.4: 65.09 ± 2.87 Omnicam 4.6.1: 52.73 ± 3.31 Medit i500: 58.45 ± 2.63 Trios 3: 41.79 ± 4.42). Preparation depth had no significant influence on the trueness (p = 0.083). For precision two-way ANOVA revealed significant differences between the different types of scanners (p < 0.001). Preparation depth had no significant influence on the precision (p = 0.111). Statistically significant interactions were found between the different variables. CONCLUSIONS: The depth of preparation did not have an influence on the accuracy of different scanners. However, the type of scanner influenced the accuracy of digital impressions with Trios3 showing the highest accuracy.

Color and translucency of repressed lithium disilicate glass ceramic subjected to multiple firings and aging / Cor e translucidez da vitrocerâmica de dissilicato de lítio reprensada submetida a múltiplas queimas e ao envelhecimento

Objetivo: O objetivo deste estudo é avaliar o efeito de múltiplas queimas e envelhecimento na cor e na translucidez da vitrocerâmica de dissilicato de lítio reprensada (IPS e.max press). Material e Métodos: Um total de 42 discos de dissilicato de lítio (15 mm x 1 mm) foram fabricados usando a técnica de prensa térmica seguindo as instruções dos fabricantes. Eles foram divididos em três grupos de acordo com o número de ciclos de prensagem (n=14): Grupo P1 (pressionado uma vez), Grupo P2 (pressionado duas vezes) e Grupo P3 (pressionado três vezes). Cada grupo foi subdividido em dois subgrupos de acordo com o número de ciclos de queima (n=7): Subgrupo (F2): 2 ciclos de queima, Subgrupo (F4): 4 ciclos de queima. Em seguida, todos os corpos de prova foram submetidos à termociclagem. Os parâmetros de cor e translucidez (TP) foram avaliados por espectrofotômetro; após a prensagem, queima (ΔE1: diferença de cor entre prensagem e queima) e envelhecimento (ΔE2: diferença de cor entre prensagem e envelhecimento). Resultados:ΔE1 para o subgrupo F2 (3,38) apresentou menor valor estatisticamente significante do que ΔE1 para o subgrupo F4 (3,94). Após o envelhecimento, o grupo P3 apresentou o maior ΔE2 estatisticamente significante (6,41). Um ΔE2 estatisticamente inferior foi encontrado no grupo P2 (5,55). O grupo P1 apresentou o menor ΔE2 estatisticamente significante (4,28). O TP para o subgrupo F2 (18,27) apresentou valor superior ao subgrupo F4 (17,78). Houve uma diminuição estatisticamente significante no TP após o envelhecimento para todos os grupos testados. Conclusão: O aumento do número de ciclos de queima e de envelhecimento afetaram a cor e a translucidez do dissilicato de lítio reprensado. (AU)

Objective: The aim of this study is to evaluate the effect of multiple firings and aging on color and translucency of repressed lithium disilicate glass ceramic (IPS e.max press). Material and Methods: A total of 42 lithium disilicate discs (15 mm x 1 mm) were fabricated using heat press technique following the manufacturers' instructions. They were divided into three groups according to the number of pressing cycles (n=14): Group P1 (pressed once), Group P2 (pressed twice) and Group P3 (pressed thrice). Each group was subdivided into two subgroups according to the number of firing cycles (n=7): Subgroup (F2): 2 firing cycles, Subgroup (F4): 4 firing cycles. Then all specimens were subjected to thermocycling. Color and translucency parameter (TP) were evaluated by spectrophotometer; after pressing, firing (ΔE1: color difference between pressing and firing) and aging (ΔE2: color difference between pressing and aging). Results:ΔE1 for subgroup F2 (3.38) showed statistically significant lower value than ΔE1 for subgroup F4 (3.94). After aging, group P3 showed the statistically significant highest ΔE2 (6.41). A statistically significant lower ΔE2 was found with group P2 (5.55). Group P1 showed the statistically significant lowest ΔE2 (4.28). TP for subgroup F2 (18.27) showed higher value than subgroup F4 (17.78). There was a statistically significant decrease in TP after aging for all tested groups. Conclusion: Increasing the number of firing cycles and aging affected color and translucency of repressed lithium disilicate. (AU)

Predictive Factors of De Novo Malignancies After Living-Donor Liver Transplantation: A Single-Center Experience.

BACKGROUND: De novo malignancies are a major reason of long-term mortalities after liver transplantation. However, they usually receive minimal attention from most health care specialists. The current study aims to evaluate our experience of de novo malignancies after living-donor liver transplantation (LDLT). METHODS: We reviewed the data of patients who underwent LDLT at our center during the period between May 2004 and December 2018. RESULTS: During the study period, 640 patients underwent LDLT. After a mean follow-up period of 41.2 ± 25.8 months, 15 patients (2.3%) with de novo malignancies were diagnosed. The most common de novo malignancies were cutaneous cancers (40%), post-transplantation lymphoproliferative disorders (13.3%), colon cancers (13.3%), and breast cancers (13.3%). Acute cellular rejection (ACR) episodes occurred in 10 patients (66.7%). Mild ACR occurred in 8 patients (53.3%), and moderate ACR occurred in 2 patients (13.3%). All patients were managed with aggressive cancer treatment. The mean survival after therapy was 40.8 ± 26.4 months. The mean overall survival after LDLT was 83.9 ± 52.9 months. Twelve patients (80%) were still alive, and 3 mortalities (20%) occurred. The 1-, 5-, and 10-year overall survival rates after LDLT were 91.7%, 91.7%, and 61.1%, respectively. On multivariate regression analysis, smoking history, operation time, and development of ACR episodes were significant predictors of de novo malignancy development. CONCLUSIONS: Liver transplant recipients are at high risk for the development of de novo malignancies. Early detection and aggressive management strategies are essential to improving the recipients' survival.

The role of neoadjuvant FLOT chemotherapy with and without omega 3 in locally advanced gastric carcinoma.

PURPOSE: Gastric is the third leading cause of cancer-related deaths worldwide with two third of the cases presented in advanced stage with resultant increased morbidity and mortality. The purpose of the study was to investigate the nutritional intervention with and without omega 3 fatty acids. METHODS: Forty two cases were randomized into two groups: group; A: FLOT neoadjuvant chemotherapy with omega 3 and group B: FLOT chemotherapy alone in the period from July 2018 to July 2019. We evaluated the radicality of surgical interference, overall response, nutritional status, treatment delivery and toxicity. RESULTS: The radicality, overall response the SGA score and the bioelectrical impedance parameters were higher in those who received omega 3 with chemotherapy and toxicity was less which was statistically significant. CONCLUSIONS: Omega 3 administrations during chemotherapy in gastric cancer increased the chemotherapy tolerability and decreased the treatment gap between cycles and hence improved gastric cancer resection.

Effect of Surface Treatment of Two Ceramic Materials by Er, Cr:YSGG Laser Irradiation on The Shear Bond Strength to Resin Cement: "a Comparative in-Vitro Study" / Efeito do tratamento de superfície de dois materiais cerâmicos por Irradiação de laser Er, Cr:YSGG na resistência ao cisalhamento a cimento Resinoso: "um estudo comparativo in-Vitro"

Objective: The aim of this study is to assess the effect of Er,Cr:YSGG laser on the shear bond strength (SBS) and surface topography of two CAD/CAM ceramic materials bonded with self adhesive resin cement. Material and methods: sixty ceramic CAD/CAM discs were obtained, 30 lithium disilicate (IPS Emax) (Group LD), and 30 hybrid resin ceramic (Vita Enamic) (Group RC). The Slices were allocated into six groups (n=10) according to ceramic material and surface treatment; Group (LD-C): IPS Emax treated with 9% hydrofluoric acid (HF), Groups (LD-L1) and (LD-L2): IPS Emax treated with Er,Cr:YSGG, Group (RC-C): Vita Enamic treated with 9% hydrofluoric acid (HF), Groups (RC-L1) and (RC-L2): Vita Enamic treated with Er,Cr:YSGG laser. The laser parameters and irradiation protocol was 1.5 W (L1) and 2.5 W (L2). All samples were cemented with self-adhesive resin cement and thermocycled for 5000 cycles. The SBS was measured using a universal testing machine and the mean values (MPa) were analyzed using Two-way (ANOVA) (P ≤ 0.05) and Bonferroni's post-hoc test. Results: RC-C (16.55) showed highest SBS followed by LD-C (13.79), which revealed no statistically significant difference with RCP1 (12.33) and RC-P2 (11.2). The lowest SBS values were found with LD-P1 (2.7) and LDP2 (2.1). SEM analysis revealed Vita Enamic to have the highest surface roughness. Fracture pattern analysis showed adhesive failure with IPS Emax groups and mixed failure with Vita Enamic groups. Conclusion: Er,Cr:YSGG laser irradiation with the parameters used did not increase SBS of IPS Emax and Vita Enamic with composite resin compared to HF acid etching (AU)

Objetivo: O objetivo deste estudo é avaliar o efeito do laser Er,Cr:YSGG na resistência ao cisalhamento (SBS) e na topografia superficial de dois materiais cerâmicos CAD/CAM cimentados com cimento resinoso autoadesivo. Material e métodos: foram obtidos sessenta discos cerâmicos CAD/CAM, 30 de dissilicato de lítio (IPS Emax) (Grupo LD) e 30 de resina híbrida (Vita Enamic)(Grupo RC). Os discos foram alocados em seis grupos (n = 10), de acordo como material cerâmico e o tratamento de superfície; Grupo (LD-C): IPS Emaxtratado com ácido fluorídrico (HF) a 9%, Grupos (LD-L1) e (LD-L2): IPS Emaxtratado com Er,Cr:YSGG, Grupo (RC-C): Vita Enamic tratada com ácido fluorídrico (HF) a 9%, Grupos (RC-L1) e (RC-L2): Vita Enamic tratada com laser Er,Cr:YSGG. Os parâmetros do laser e o protocolo de irradiação foram de 1,5 W (L1) e 2,5 W (L2). Todas as amostras foram cimentadas com cimento resinoso autoadesivo e termocicladas por 5000 ciclos. A SBS foi medida usando uma máquina de ensaios universais e os valores médios (MPa) foram analisados usando (ANOVA) a dois fatores (P ≤ 0,05) e teste post-hoc de Bonferroni. Resultados: RC-C (16,55) apresentou maior SBS seguido por LD-C (13,79), que não revelou diferença estatisticamente significante com RCP1(12,33) e RC-P2 (11,2). Os menores valores de SBS foram encontrados comLD-P1 (2,7) e LD-P2 (2,1). A análise por MEV revelou que a Vita Enamic possui maior rugosidade de superfície. A análise do padrão de fratura mostrou falha adesiva nos grupos IPS Emax e falha mista nos grupos Vita Enamic. Conclusão: A irradiação com laser Er,Cr:YSGG com os parâmetros utilizados não aumentou a SBS de IPS Emax e Vita Enamic ao cimento resinoso em comparação com o condicionamento ácido com HF.(AU)

The Effect of Different Wax Pattern Fabrication Techniques on the Marginal Fit of Customized Lithium Disilicate Implant Abutments.

PURPOSE: To evaluate the effect of different wax pattern fabrication techniques on the fit of customized pressed lithium disilicate implant abutments on titanium inserts before and after pressing. The marginal fit results of pressed lithium disilicate implant abutments were then compared with those of milled lithium disilicate abutments. MATERIALS AND METHODS: After scanning the titanium inserts and designing an implant abutment, wax patterns were fabricated with three techniques (n = 15 each): computer-aided design/computer-aided manufacturing (CAD/CAM) milling, 3D printing and conventional layering. The marginal fit (µm) was measured using a stereomicroscope for all the wax patterns before pressing them into the lithium disilicate abutments. The pressed implant abutments were measured again for marginal fit, and the results were compared to those of the milled lithium disilicate abutments. One-way analysis of variance (ANOVA) was used to assess different wax pattern fabrication techniques in each stage before and after pressing. One-way ANOVA was also used to compare the groups of pressed and milled lithium disilicate abutments. Multiple pairwise comparisons were performed using the Tukey post hoc test in each stage. RESULTS: There were statistically significant differences between the marginal fit of the three wax patterns groups (p < 0.001; f = 123.33), wherein the mean marginal fit was the highest for conventionally layered wax patterns (30 ± 13.09) µm. Furthermore, after pressing, there were statistically significant differences between the marginal fit of the three pressed abutments groups (p < 0.001; f = 518.62), wherein the mean marginal fit was the highest for pressed e.max abutments fabricated from conventionally layered wax patterns (25.26 ± 3.9) µm. There was no statistically significant difference between the mean marginal fit of the pressed abutments fabricated from conventional layered wax patterns and that of the milled CAD/CAM abutments. However, the mean marginal fit of the milled CAD/CAM abutments was higher than that of the pressed abutments fabricated from both CAD/CAM wax and 3D printed wax. CONCLUSION: All the tested fabrication methods provided degrees of accuracy that lie well within accepted limits. The use of pressed lithium disilicate abutments fabricated from conventional layering wax pattern technique should provide a more consistent better marginal fit between the titanium insert and the abutment and may therefore be the preferable fabrication method.

Clamp-Crush Technique Versus Harmonic Scalpel for Hepatic Parenchymal Transection in Living Donor Hepatectomy: a Randomized Controlled Trial.

BACKGROUND: Hepatic parenchymal transection is the most invasive step in donor operation. During this step, blood loss and unintended injuries to the intrahepatic structures and hepatic remnant may occur. There is no evidence to prove the ideal techniques for hepatic parenchymal transection. The aim of this study is to compare the safety, efficacy, and outcome of clamp-crush technique versus harmonic scalpel as a method of parenchymal transection in living-donor hepatectomy. METHODS: Consecutive living liver donors, undergoing right hemi-hepatectomy, during the period between May 2015 and April 2016, were included in this prospective randomized study. Cases were randomized into two groups; group (A) harmonic scalpel group and group (B) Clamp-crush group. RESULTS: During the study period, 72 cases underwent right hemi-hepatectomy for adult living donor liver transplantation and were randomized into two groups. There were no statistically significant differences between the two groups regarding preoperative demographic and radiological data. Longer operation time and hepatectomy duration were found in group B. There were no significant differences between the two groups regarding blood loss, blood loss during hepatectomy, and blood transfusion. More unexpected bleeding events occurred in group A. Higher necrosis at the cut margin of the liver parenchyma was noted in group A. There were no statistically significant differences between the two groups regarding postoperative ICU stay, hospital stay, postoperative morbidities, and readmission rates. CONCLUSION: Clamp-crush technique is advocated as a simple, easy, safe, and cheaper method for hepatic parenchymal transection in living donors.

Adrenalectomy for solitary recurrent hepatocellular carcinoma five years after living donor liver transplantation: A case report.

INTRODUCTION: The adrenal gland is a rare site for hepatocellular carcinoma (HCC) recurrence after living-donor liver transplantation (LDLT). Solitary adrenal recurrence can be managed by surgical excision, with expected better survival outcomes. We describe a rare case of successful left adrenalectomy of solitary recurrent HCC in the left adrenal gland 5 years after LDLT. PRESENTATION: 59 years male patient with HCC complicating chronic HCV infection received a right hemi-liver graft from his son. The actual graft weight was 1208 g and GRWR was 1.5. The patient started oral direct acting antiviral drugs for recurrent HCV 2 years after LDLT. A left adrenal mass was detected on follow up radiology. No other metastatic lesions were detected on metastatic workup. Left adrenalectomy was done by an anterior approach. The postoperative course was uneventful and was discharged a week after operation. Postoperative pathological and immune-histochemical examinations confirmed the metastatic HCC nature of the mass. The patient is under regular follow up with no recurrences 6 month after resection. DISCUSSION: There is no consensus regarding the management of HCC recurrence after LDLT. Most patients had multi-organ recurrences and usually offered palliative or supportive care. Solitary HCC recurrence offers a better chance for more aggressive therapy, offering better prognosis. CONCLUSION: Solitary adrenal recurrence of HCC after LDLT is extremely rare. Strict follow up protocol is necessary to allow early detection of tumor recurrence. Curative surgical resection is a safe option associated with low morbidity and expected to have a good long-term survival.

Effect of different root dentin pretreatment protocols on the bond strength of fiber posts cemented with core buildup material / Efeito de diferentes protocolos de pré tratamento de dentinas radiculares na força de adesão de pinos de fibra cimentados com material de núcleo de preenchimento

Objective: The purpose of the study was to evaluate the push out bond strength of fiber posts -after cementaion with core build up material and dentin pretreatment using different adhesive protocolsin different root regions. Material and Methods: 28 endodonticaly treated human premolars were divided into 4 groups. The post spaces were treated with 1 of 4 different dentin bonding protocols: total etch light cured adhesive, solobond m; total etch dual cured adhesive, Excite f DSC; self-etching light cured adhesive, single bond universal; or selfetching dual cured adhesive, futura bond dc. Fiber posts, were luted with dual cured core material. The roots were cut into 2-mm-thick sections, in cervical, middle, and apical regions. Push-out tests were performed with a universal testing machine, and bond strength values (MPa) were calculated. Data were analyzed with 1- and 2-way analysis of variance and Tukey multiple comparison tests (a=.05). Failure modes were examined under stereo microscope. Results: The highest mean bond strength values were obtained for self-etch dual cured adhesive, (9.69 MPa). The Total etch light cured adhesive (2.81 MPa) showed the lowest bond strength. Self-etch light-polymerized and total etch dual-polymerized adhesives provided similar bond strengths (5.37, 5.72 respectively). The regional bond strength values were reduced significantly in apical post space (P<0.01). The most predominant failure type was mixed failure followed by adhesive failure. Conclusion: Dentin pretreatment using self-etch dual cured adhesives prior to fiber posts cementation offers a high bond strength. While using total-etch light cured adhesives is not recommended due to the low bonding quality.(AU)

Objetivo: O objetivo do estudo foi avaliar a força de adesão dos pinos de fibra após o cimentação com material de núcleo e o pré-tratamento da dentina utilizando diferentes protocolos adesivos em diferentes regiões radiculares. Material e Métodos: 28 pré-molares humanos tratados endodonticamente foram divididos em 4 grupos. Os condutos foram tratados com 1 de 4 diferentes protocolos de união à dentina: adesivo fotopolimerizável total, solobond m; adesivo de polimerização dual de condicionamento total, Excite f DSC; adesivo fotopolimerizável autocondicionante, Single Bond universal; ou adesivo de dupla curado autocondicionante, futura bond dc. Núcleos de fibra, foram cimentados com material resinoso e polimerizados. As raízes foram cortadas em seções de 2 mm de espessura, nas regiões cervical, média e apical. Testes de push-out foram realizados com uma máquina de testes universal, e os valores de resistência de união (MPa) foram calculados. Os dados foram analisados com análise de variância de 1 e 2 fatores e testes de comparação múltipla de Tukey (a = 0,05). Modos de falha foram examinados sob estéreo-microscópio. Resultados: Os valores médios mais elevados de resistência adesiva foram obtidos para o adesivo dual autocondicionante (9,69 MPa). O adesivo fotopolimerizável Total etch (2,81 MPa) apresentou a menor resistência de união. Os adesivos autocondicionantes fotopolimerizáveis e os de condicionamento tal duais, proporcionaram forças de adesão semelhantes (5,37, 5,72, respectivamente). Os valores de força de união regional foram significativamente reduzidos na região apical (P<0,01). O tipo de falha mais predominante foi falha mista seguida de falha adesiva. Conclusão: O pré-tratamento com dentina utilizando adesivos duais autocondicionantes antes da cimentação dos pinos de fibra oferece uma alta resistência de união. Enquanto que os adesivos de condicionamento total fotopolimerizáveis não sforam recomendados devido à baixa qualidade da adesão proporcionada. (AU)

Biaxial flexural strength of different types of monolithic zirconia / Resistência Flexural Biaxial de diferentes tipos de zircônia monolítica

Objective: This study was designed to evaluate the biaxial flexural strength (BFS) of different types of unshaded and shaded monolithic zirconia. Material and Methods: 120 monolithic zirconia ceramic discs were fabricated. They were divided into twelve groups (n=10), Group 1; Bruxzir unshaded, Group 2; Bruxzir shaded A2, Group 3; Bruxzir anterior white, Group 4; Bruxzir anterior shade A2, Group 5; Prettau unshaded, Group 6; Prettau shaded with A2 coloring liquid, Group 7; Prettau anterior white, Group 8; Prettau anterior shaded with A2 coloring liquid, Group 9; Katana HT white, Group 10; Katana HT shade A2, Group 11; Katana ST white, Group 12; Katana ST shade A2. All discs were milled using a dental milling machine, and had final dimensions after sintering of 15 mm diameter and 1 mm thickness. BFS was tested using piston on three ball technique. Results: One-way ANOVA revealed significant differences among the 12 groups. Tukey post-hoc tests revealed no significant differences between the groups 3, 4, ,7 ,8 11, and 12. However, they all had BFS values that are significantly lower than all other groups. Group 2 showed statistically significant higher BFS values when compared to group 3,4, 7, 8, 11, and 12 while it showed statistically significant lower values when compared to groups 1, 5, 6, 9, and 10. Conclusion: Increase in the yttria content in zirconia led to a decrease in its BFS. Shading of zirconia did not have a significant effect on the final strength of zirconia. (AU)

Objetivo: Este estudo foi desenhado para avaliar a resistência à flexão biaxial (RFB) de diferentes tipos de zircônia monolítica maquiada e não-maquiadas. Material e Métodos: 120 discos cerâmicos de zircônia monolítica foram fabricados. Eles foram divididos em doze grupos (n = 10), Grupo 1; Bruxzir Não-maquiado, Grupo 2; Bruxzir maquiado A2, Grupo 3; Branco anterior de Bruxzir, Grupo 4; Maquiagem anterior de Bruxzir A2, Grupo 5; Prettau não maquiado, Grupo 6; Prettau maquiado com corante A2, Grupo 7; Prettau anterior branco, Grupo 8; Prettau anterior maquiado com corante A2, Grupo 9; Katana HT branco, Grupo 10; Katana HT maquiagem A2, Grupo 11; Katana ST White, Grupo 12; Katana ST maquiagem A2. Todos os discos foram fresados em uma fresadora dentária e tiveram suas dimensões finais após sinterização de 15 mm de diâmetro e 1 mm de espessura. A RFB foi testado usando pistão na técnica de três bolas. Resultados: One-way ANOVA revelou diferenças significativas entre os 12 grupos. Os testes post-hoc de Tukey não revelaram diferenças significativas entre os grupos 3, 4, 7, 8 11 e 12. No entanto, todos eles exibiram valores de RFB significativamente menores do que todos os outros grupos. O Grupo 2 apresentou valores estatisticamente significantes de ICS mais elevados quando comparado aos grupos 3,4, 7, 8, 11 e 12, enquanto apresentou valores estatisticamente significantes menores quando comparados aos grupos 1, 5, 6, 9 e 10. Conclusão: o aumento do conteúdo de ítria na zircônia levou a uma diminuição em sua RFB. A maquiagem da zircônia não teve um efeito significativo sobre a resistência final da zircônia. (AU)

Assessment of marginal adaptation and fracture resistance of endocrown restorations utilizing different machinable blocks subjected to thermomechanical aging.

OBJECTIVE: This in vitro study was conducted to assess the marginal adaptation and fracture resistance of computer aided design/computer aided manufacturer (CAD-CAM) fabricated endocrowns restoring endodontically treated molars using different machinable blocks with thermomechanical loading protocols. MATERIALS AND METHODS: Devitalized mandibular molars were prepared in a standardized way and divided into 4 groups (n = 10) to receive CAD/CAM fabricated endocrowns using four materials (Lithium disilicate ceramics, polymer infiltrated ceramics, zirconia-reinforced lithium silicate ceramics and resin nanoceramics. Marginal gaps (µm) were measured using stereomicroscope before cementation and after cementation. After thermomechanical aging, marginal gap measurements were repeated, and then fracture resistance test was performed. Two-way analysis of variance (ANOVA) and Tukey HSD multiple comparisons were used to assess the effect of material on the marginal gap before, after cementation, and after thermomechanical aging. One Way ANOVA was used to assess the effect of material on the fracture resistance. RESULTS: The difference between marginal gaps values of the tested materials was statistically insignificant but with significant increase after cementation and after thermomechanical aging. Cerasmart endocrowns showed the highest mean fracture load value (1508.5 ± 421.7N) with statistically significant difference than Vita Enamic endocrowns and Celtra Duo. CONCLUSION: The tested materials showed marginal vertical gap readings within the limits of clinically acceptable standards. Resin nanoceramics and lithium disilicate showed the highest values of fracture resistance followed by polymer infiltrated ceramics favoring their use for endocrown restorations. CLINICAL SIGNIFICANCE: The mechanical behavior of ceramic materials varies with the variation of their structure and mechanical properties. Accordingly, further investigation is always needed to explore the biomechanical behavior of recent materials when used as endocrowns before clinical trials.