Does a Self-etching Ceramic Primer Improve Bonding to Lithium Disilicate Ceramics? Bond Strengths and FESEM Analyses

2019 ◽  
Vol 44 (2) ◽  
pp. 210-218 ◽  
Author(s):  
GC Lopes ◽  
J Perdigão ◽  
D Baptista ◽  
A Ballarin

SUMMARY Objective: To compare the effect of hydrofluoric acid (HF) vs self-etching ceramic primer on resin cement microshear bond strength (μSBS) and ultramorphology of lithium disilicate (LD) ceramic. Methods and Materials: LD (IPS e.max CAD, Ivoclar Vivadent) blocks (14×4×2 mm3) were polished to 1200 grit and assigned to nine groups (n=5): CON: control, no LD surface treatment; IVO: 5.0% HF (IPS Ceramic Etching Gel, Ivoclar Vivadent); VIT: 5.0% HF (Vita Ceramics Etch, VITA Zahnfabrik); FGM: 5.0% HF (Condac Porcelana, FGM); ULT: 9.0% HF (Porcelain Etch, Ultradent); PRM: 9.6% HF (Premier Porcelain Etch Gel, Premier); BIS: 9.5% HF (Porcelain Etchant, Bisco Inc); DEN: 10.0% HF (Condicionador de Porcelanas, Dentsply Brazil); and MEP: self-etching ceramic primer (Monobond Etch & Prime, Ivoclar Vivadent). For all HF groups and control, an MDP-containing silane solution (MB+, Monobond Plus, Ivoclar Vivadent) was applied on rinsing the HF gel and air drying. Three transparent matrices for each specimen were filled with light-cured resin cement (Variolink Veneer, Ivoclar Vivadent). After storage in water for 48 hours at 37°C, specimens were tested in shear mode to measure μSBS. Mode of failure was analyzed at 50×. Statistical analysis included one-way analysis of variance and the Duncan post hoc test (α=0.05). Thirty-six additional LD specimens were assigned to the same experimental groups (n=4) and observed under a field-emission scanning electron microscope (FESEM) at magnifications ranging from 10,000× to 100,000×. Results: IVO resulted in statistically higher mean μSBS than all the other groups. MEP resulted in statistically lower μSBS than all HF groups. The failure mode for MEP was predominantly adhesive. The most frequent failure mode for the HF groups was mixed. CON resulted in 100% pretesting failures. For FESEM, no retentive pattern was observed for CON specimens. MEP resulted in the least pronounced etching pattern, few areas around crystals exhibited a slight increase in retention pattern compared to the control group. All HF gels created microporosities on the LD surface with distinct etching patterns. VIT and DEN resulted in an LD ultramorphology that suggested overetching. Conclusions: HF etching followed by a silane solution resulted in higher bond strengths than a self-etching ceramic primer. Some HF gels may cause overetching of the LD intaglio surface.

2015 ◽  
Vol 40 (5) ◽  
pp. 524-532 ◽  
Author(s):  
DP Lise ◽  
J Perdigão ◽  
A Van Ende ◽  
O Zidan ◽  
GC Lopes

SUMMARY Objectives To investigate the effect of hydrofluoric acid (HF) etching, silane solution, and adhesive system application on the microshear bond strength (μSBS) of lithium disilicate glass-ceramic (LD) to three resin cements. Materials and Methods Circular bonding areas were delimited on the lithium disilicate surfaces using a perforated adhesive tape. Specimens were assigned to 18 subgroups (n=12) according to surface treatment: NT = no treatment; HF = 4.8% HF for 20 seconds; silane solution: (1) no silane; (2) Monobond Plus, a silane/10-methacryloyloxydecyl dihydrogen phosphate solution for 60 seconds; (3) Monobond Plus+ExciTE F DSC, a dual-cure adhesive; and resin cement: (1) Variolink II, a bisphenol A diglycidyl ether dimethacrylate (bis-GMA)–based, hand-mixed, dual-cure resin cement; (2) Multilink Automix, a bis-GMA–based, auto-mixed, dual-cure resin cement; (3) RelyX Unicem 2, a self-adhesive, auto-mixed, dual-cure resin cement. Tygon tubes (Ø=0.8 mm) were used as cylinder matrices for resin cement application. After 24 hours of water storage, the specimens were submitted to the μSBS test. Mode of failure was evaluated under an optical microscope and classified as adhesive, mixed, cohesive in resin cement, or cohesive in ceramic. Data were statistically analyzed with three-way analysis of variance and Dunnett test (p<0.05). Results When means were pooled for the factor surface treatment, HF resulted in a significantly higher μSBS than did NT (p<0.0001). Regarding the use of a silane solution, the mean μSBS values obtained with Monobond Plus and Monobond Plus+ExciTE F DSC were not significantly different but were higher than those obtained with no silane (p<0.001). Considering the factor resin cement, Variolink II resulted in a significantly higher mean μSBS than did RelyX Unicem 2 (p<0.03). The mean μSBS for Multilink Automix was not significantly different from those of Variolink II and RelyX Unicem 2. According to Dunnett post hoc test (p<0.05), there was no significant difference in μSBS between the different resin cements for HF-etched and silanized (with or without adhesive application) LD surfaces. Conclusion LD may benefit from pretreatment of the inner surface with HF and silanization, regardless of the resin cement used.


2016 ◽  
Vol 27 (4) ◽  
pp. 458-462 ◽  
Author(s):  
Celso Sebastião Garboza ◽  
Sandrine Bittencourt Berger ◽  
Ricardo Danil Guiraldo ◽  
Ana Paula Piovezan Fugolin ◽  
Alcides Gonini-Júnior ◽  
...  

Abstract The purpose of this study was to evaluate the microshear bond strength of ceramic prosthetic structures reinforced by lithium disilicate cemented with resin cement under conditions of different surface treatments and adhesive systems. Seventy-two rectangular blocks of lithium disilicate (6.5 mm long × 5 mm wide × 1 mm thick) were fabricated, air abraded with 50-μm Al2O3 particles and divided into six groups (n=12) depending on the surface pretreatments. The groups were as follows: 10HF/S/SBM: 10% hydrofluoric acid etched for 20 s (10HF) + silane (S) + Adper Scotchbond Multi-Purpose (SBM); 10HF/S/SB: 10HF + S + Single Bond Universal (SB); 10HF/SBM; 10HF/SB; S/SBM and S/SB. Two 1-mm-long plastic tubes were placed on the specimens, filled with RelyX ARC resin cement and cured for 20 s per tube. The plastic tube was removed, and the microshear bond strength was tested. Data were submitted to analysis of variance and Tukey's tests (α=0.05). Fractured specimens were observed under optical microscopy. For both adhesives, the bond strengths (MPa) of groups treated with acid-etching and silane (10HF/S/SB: 24.82, 10HF/S/SBM: 24.90) were higher (p<0.001) than those of groups treated with acid-etching (10HF/SB: 16.47, 10HF/SBM: 19.94) only or only silane (S/SB: 18.42, S/SBM: 13.24). All groups showed a predominance of failure adhesive. The silanization should be a clinical step in cementing ceramic structures reinforced by lithium disilicate, even with the application of universal adhesive that contains silane in its formulation.


2020 ◽  
pp. 270-278

INTRODUCTION: The enhancement of nurses’ risk perception plays a significant role in their preparedness during disasters and emergencies. Therefore, this study aimed to investigate the effect of educational workshops on disaster risk perception in nurses METHODS: This randomized controlled field trial study included 62 nurses working at Razi Hospital, Birjand, Iran. The participants were divided into intervention and control groups. The intervention group was then requested to participate in a one-day intensive educational workshop based on the current national standards. The workshop content included a combination of lecturing methods, round-table exercises, and film display. The data were collected using the demographic characteristic form and researcher-made questionnaires measuring the nurses’ risk perception during disasters and emergencies. Subsequently, the data were analyzed using independent t-test, repeated measures analysis, and Bonferroni post hoc tests. FINDINGS: The mean total score of risk perception were significantly higher in the intervention group before, immediately, and two months after the workshop session, compared to those in the control group (P˂0.001). CONCLUSION: The implementation of nurses’ national preparation program during disasters and emergencies can result in an increase in the nurses’ risk perception during these events. Therefore, regarding the importance of nurses’ preparedness in confrontation with disasters and emergencies, it seems necessary to integrate the National Preparedness Program into the educational programs immediately after recruitment and in the form of in-service courses.


2021 ◽  
Author(s):  
Arkadiusz Żurawski ◽  
Zbigniew Śliwiński ◽  
Grażyna Nowak Starz ◽  
Wojciech Kiebzak (Kiebzak)

Abstract BackgroundDue to numerous complications of an abnormal shape of the spine, it is extremely important to systematically monitor its shape. Precise and routine method of measurement enables comparison of the scores obtained over time and possible early intervention in order to avoid complications.The aim of the work is to present the pattern for monitoring changes in the shape of the spine in children with postural deformities.MethodsThe study group (n = 211) consisted of the patients with diagnosed shape of the spine deformity, who underwent a four-month therapy, supervised by a physiotherapist. The control group (n = 101) were the children with no shape of spine deformity.The children in the study group underwent a three-dimensional computer analysis of the shape of the spine. The DIERS test was performed in both groups (study and control). In the study group it was performed four times. It involved the measurement of seven parameters enabling a complete assessment of body posture.ResultsStatistically significant scores of the Friedman test for imbalance, pelvic tilt, kyphosis angle, lordosis angle, and lateral deviation were observed. Therefore, a series of post-hoc analyzes were performed using Dunn-Bonferroni tests. It was observed that changes in individual parameters analyzed in the authors' study come up at a different pace.ConclusionsDetailed monitoring of the parameters describing the position of the spine makes it possible to control the course of the treatment process of patients with disorders of the position of the spine. The dynamics of changes taking place within the spine position varies for the individual parameters analyzed.


2015 ◽  
Vol 40 (1) ◽  
pp. 55-62 ◽  
Author(s):  
J-H Kim ◽  
S-Y Chae ◽  
Y Lee ◽  
G-J Han ◽  
B-H Cho

SUMMARY This study evaluated the effects of single-bottle, multipurpose, universal adhesives on the bond strength of resin cement to zirconia ceramic. Polished zirconia ceramic (Cercon base) discs were randomly divided into four groups (n=40) according to the applied surface-conditioning agent: Single Bond 2, Single Bond Universal, All-Bond Universal, and Alloy Primer. Cured composite cylinders (Ø 0.8 mm × 1 mm) were cemented to the conditioned zirconia specimens with resin cement (RelyX ARC). The bonded specimens were subjected to a microshear bond-strength test after 24 hours of water storage and after 10,000 cycles of thermocycling. The surface-conditioning agent significantly influenced the bond strength (p&lt;0.05). Single Bond Universal showed the highest initial bond strength (37.7 ± 5.1 MPa), followed by All-Bond Universal (31.3 ± 5.6 MPa), Alloy Primer (26.9 ± 5.1 MPa), and Single Bond 2 (8.5 ± 4.6 MPa). Artificial aging significantly reduced the bond strengths of all the test groups (p&lt;0.05). After 10,000 cycles of thermocycling, All-Bond Universal showed the highest bond-strength value (26.9 ± 6.4 MPa). Regardless of artificial aging, Single Bond Universal and All-Bond Universal showed significantly higher bond strengths than Alloy Primer, a conventional metal primer.


2019 ◽  
Vol 90 (1) ◽  
pp. 85-91 ◽  
Author(s):  
Abhishekhi Shrestha ◽  
Masahiro Takahashi ◽  
Tetsutaro Yamaguchi ◽  
Mohamed Adel ◽  
Mayu Furuhata ◽  
...  

ABSTRACT Objectives To examine the relationship between mandibular volume and craniofacial morphology in patients with cleft lip and palate using cone beam computed tomography (CBCT) and to compare these findings with control (noncleft) patients undergoing CBCT for other purposes during the deciduous dentition period. Materials and Methods Eighty-four patients were categorized into the unilateral cleft lip and alveolus (UCLA) group (n = 25; mean age, 4.60 ± 0.40 years), unilateral cleft lip and palate (UCLP) group (n = 23; mean age, 4.52 ± 0.39 years), bilateral cleft lip and palate (BCLP) group (n = 22; mean age, 4.54 ± 0.37 years), and control group without cleft (n = 14; mean age, 5.19 ± 0.52 years). Mandibular volume and craniofacial cephalometric measurements were obtained using CBCT. All measurements were assessed by analysis of covariance (ANCOVA) using Bonferroni post hoc pairwise comparison tests. Results ANCOVA revealed no statistically significant differences in mandibular volume among the groups. SNA° and ANB° were significantly larger in the UCLA and BCLP groups than in the control group. SN-MP° was smallest in the UCLA group. Co-A in the UCLP group was shorter than in the UCLA and BCLP groups. Go-Gn was shortest in the UCLP and BCLP groups compared with the control group. Conclusions Three-dimensional evaluation of craniofacial morphology using CBCT can provide valuable information on malocclusion and other dentoskeletal problems among patients with CLP.


2019 ◽  
Vol 39 (5) ◽  
pp. 447-454
Author(s):  
Steve S. Wong ◽  
Wai-Yan Lau ◽  
Yim-Yuk Tse ◽  
Ping-Kwan Chan ◽  
Ching-Kit Wan ◽  
...  

Background In severe peritoneal dialysis (PD)-related peritonitis, patients’ response to antibiotic can be poor. We postulated that adjunctive lavage may improve the outcome in severe cases by enhancing the removal of bacteria and inflammatory cells from the peritoneum. Methods Severe PD peritonitis was defined as poor clinical response to empirical cefazolin/ceftazidime and a PD effluent (PDE) leukocyte count > 1,090/mm3 on day 3. Enrolled patients were randomized into either the lavage group ( n = 20) or control group ( n = 20). In the lavage group, continuous lavage by an automated PD machine from day 3 to 5 or 6 was performed, whereas the usual PD schedule was maintained in the control group. The primary outcome was treatment success. Post hoc analysis was also performed to compare the outcome between subgroups with different severity. Results Baseline parameters were similar in the lavage and control groups, including PDE leukocyte count on day 3 (4,871/mm3 vs 4,143/mm3, p = 0.46). Treatment success rates were high in both groups (75% vs 70%, p = 0.72). C-reactive protein (CRP) on day 3 was found to be the only predictor of treatment failure and was used to stratify all patients into tertiles of severity. Whilst a significant decline in treatment success was evident across the tertiles of increasing CRP in the control group (100% vs 85.7% vs 28.6%, p = 0.005), treatment success was relatively maintained in the lavage group (85.7% vs 71.4% vs 66.7%, p = 0.43). Conclusions Adjunctive lavage did not improve the overall outcome, although it may be beneficial for the more severe peritonitis patients who have high CRP.


2016 ◽  
Vol 27 (6) ◽  
pp. 727-733 ◽  
Author(s):  
Daniel Sundfeld ◽  
Lourenço Correr-Sobrinho ◽  
Núbia Inocêncya Pavesi Pini ◽  
Ana Rosa Costa ◽  
Renato Herman Sundfeld ◽  
...  

Abstract The aim of this study was to evaluate the effects of hydrofluoric acid (HF) concentration and previous heat treatment (PHT) on the surface morphology and micro-shear bond strength (mSBS) of a lithium disilicate glass ceramic (EMX) to resin cement. One hundred four EMX specimens were randomly assigned to two groups (n=52) according to the HF concentration: 5% and 10%. A new random distribution was made according to the PHTs (n=13): control (no PHT); previously heated HF (70 °C); previously heated EMX surface (85 °C); the combination of heated HF + heated EMX surface. The etching time was set at 20 s. All EMX blocks were silanated and received a thin layer of an unfilled resin. Five resin cement cylinders were made on each EMX surface using Tygon tubes as matrices, and then stored for 24 h at 37 °C. One random etched EMX sample from each group was analyzed using field-emission scanning electron microscopy (FE-SEM). The data were subjected to two-way ANOVA and multiple comparisons were performed using the Tukey post hoc test (a=0.05). For the control groups, 5% HF showed statistically lower mSBS values when compared to 10% HF (p<0.05). PHT increased the mSBS values for 5% HF, yielding statistically similar results to non-PHT 10% HF (p<0.05). FE-SEM images showed increased glassy matrix removal when PHT was applied to HF 5%, but not to the same degree as for 10% HF. PHT has the potential to improve the bond strength of 5% HF concentration on lithium disilicate glass ceramic.


2019 ◽  
Vol 31 (1) ◽  
pp. 171
Author(s):  
R. Dupras ◽  
L. Mills ◽  
G. Robert ◽  
C. Meunier ◽  
Y. Chorfi

The aim of this study was to determine the effect of propylene glycol (PPG) on serum concentrations of insulin and insulin-like growth factor (IGF)-1 in superovulated dairy heifers. We hypothesised that administration of PPG would have a positive effect on superovulation results via increased insulin and IGF-1. A total of 20 clinically healthy Holstein heifers with an average age of 12 months were used for this experiment. Superovulation was performed using a standard protocol. Briefly, each heifer received 3mg of oestradiol-17β IM and an intravaginal progesterone-releasing insert (CIDR) containing 1.9g of progesterone at random stages of the oestrous cycle (designated Day 0). From Day 4 to 8, heifers received a total of 200mg of NIH-follicle-stimulating hormone-P1 administered intramuscularly through 9 injections of decreasing doses (from 50 to 10mg) at 12-h intervals. On Day 7, heifers received 2 injections of 500µg of cloprostenol, a PGF2α analogue, at ~6-h intervals, after which intravaginal inserts were removed. Artificial insemination was performed on Day 10, 12h after treatment with 100µg of gonadotropin-releasing hormone IM. Embryos were flushed from the uterus of donor heifers 6 days after AI. The method consisted of simultaneously using 1 catheter per uterine horn. Catheters were maintained in place to perform 2 flushes 1h apart. A total of 1L of flushing medium was used, 700 and 300mL for the first and the second flush, respectively. Embryos were assessed for viability immediately after collection using the IETS classification. Heifers were divided into 2 groups (PPG and control group). From Day 4 to 14 of the superovulation protocol, PPG group received a daily dose of 400mL of a 66.7% propylene glycol solution, whereas the control group received the same amount of water. Two months later, the same experiment was conducted by inverting the groups. At Day 4 and 14, four blood samples were collected to measure insulin and IGF-1 at 25-min intervals. The first sample (0) was taken before heifers received PPG or water. Insulin was analysed using an ELISA kit following manufacturer’s instructions, whereas IGF-1 was determined using a chemiluminescence immunoassay. Embryo associated data were analysed using t-test. Both IGF-1 and insulin data were analysed using a two-way ANOVA, followed by Bonferroni post-hoc test. Treatment with PPG had no effect on the number of transferable embryos (8±5.1v. 7±5.5), degenerated embryos (0.5±0.8v. 1.5±2.4), or unfertilized oocytes (0.3±0.7v. 0.7±1.2) recovered. There was also no effect of PPG on IGF-1 serum concentrations at the beginning (Day 4) or the end (Day 14) of the treatment regimen. However, PPG treatment enhanced (P = 0.02) serum insulin concentrations 50min after administration on Day 4 (10.69 v. 6.88 pmol/L), as well as at 25 (19.58 v. 9.64 pmol/L) and 50min (16.67v. 8.21 pmol/L) on Day 14. It has been suggested that PPG metabolism may stimulate insulin and IGF-1 secretion, which can promote embryo development. However, in the present study, there was no effect of oral doses of PPG on IGF-1. Although higher serum concentrations of insulin were observed after PPG treatment, there was no effect of PPG treatment on the number of transferable embryos recovered following superovulation.


2016 ◽  
Vol 41 (6) ◽  
pp. 666-671 ◽  
Author(s):  
C Gillette ◽  
R Buck ◽  
N DuVall ◽  
S Cushen ◽  
M Wajdowicz ◽  
...  

SUMMARY Objective: To evaluate the significance of reduced axial wall height on retention of adhesively luted, all-ceramic, lithium disilicate premolar computer-aided design/computer-aided manufacturing (CAD/CAM) crowns based on preparations with a near ideal total occlusal convergence of 10°. Methods: Forty-eight recently extracted premolars were randomly divided into four groups (n=12). Each group received all-ceramic CAD/CAM crown preparations featuring axial wall heights of 0, 1, 2, and 3 mm, respectively, all with a 10° total occlusal convergence. Scanned preparations were fitted with lithium disilicate all-ceramic crowns that were luted with a self-etching resin cement. Specimens were tested to failure at a 45° angle to the tooth long axis with failure load converted to megapascals (MPa) based on the measured bonding surface area. Mean data were analyzed using analysis of variance/Tukey's post hoc test (α=0.05). Results: Lithium disilicate crowns adhesively luted on preparations with 0 axial wall height demonstrated significantly less failure resistance compared with the crowns luted on preparations with axial wall heights of 1 to 3 mm. There was no failure stress difference between preparations with 1 to 3 mm axial wall height. Conclusions: Under conditions of this study, adhesively luted lithium disilicate bicuspid crowns with a total occlusal convergence of 10° demonstrated similar failure resistance independent of axial wall height of 1 to 3 mm. This study provides some evidence that adhesion combined with an ideal total occlusal convergence may compensate for reduced axial wall height.


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