scholarly journals Fracture Resistance of Ceramic Laminate Veneers Bonded to Teeth with Class V Composite Fillings after Cyclic Loading

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Leyla Sadighpour ◽  
Farideh Geramipanah ◽  
Vanya Rasaei ◽  
Mohammad J. Kharazi Fard
Keyword(s):  
Cyclic Loading ◽  
Fracture Resistance ◽  
Resin Cement ◽  
Crown Height ◽  
Class V ◽  
Significant Difference ◽  
Failure Loads ◽  
The Mean ◽  
Laminate Veneers ◽  
One Way Anova

Purpose. Porcelain laminate veneers (PLVs) are sometimes required to be used for teeth with composite fillings. This study examined the fracture strength of PLVs bonded to the teeth restored with different sizes of class V composite fillings. Materials and Methods. Thirty-six maxillary central incisors were divided into three groups (n=12): intact teeth (control) and teeth with class V composite fillings of one-third or two-thirds of the crown height (small or large group, resp.). PLVs were made by using IPS e.max and bonded with a resin cement (RelyX Unicem). Fracture resistance (N) was measured after cyclic loading (1 × 106 cycles, 1.2 Hz). For statistical analyses, one-way ANOVA and Tukey test were used (α=0.05). Results. There was a significant difference between the mean failure loads of the test groups (P=0.004), with the Tukey-HSD test showing lower failure loads in the large-composite group compared to the control (P=0.02) or small group (P=0.05). The control and small-composite groups achieved comparable results (P>0.05). Conclusions. Failure loads of PLVs bonded to intact teeth and to teeth with small class V composite fillings were not significantly different. However, extensive composite fillings could compromise the bonding of PLVs.

scholarly journals Fracture Resistance of a Bulk-Fill and a Conventional Composite and a Combination of Both for Coronal Restoration of Severely Damaged Primary Anterior Teeth

2019 ◽  
Author(s):  
Shahram Mosharrafian ◽  
Maryam Shafizadeh ◽  
Zeinab Sharifi
Keyword(s):  
Fracture Resistance ◽  
Treatment Time ◽  
Testing Machine ◽  
Anterior Teeth ◽  
Significant Difference ◽  
Group 3 ◽  
The Mean ◽  
Group 2 ◽  
One Way Anova

Objectives: This study aimed to compare the fracture resistance of a bulk-fill and a conventional composite and a combination of both for coronal restoration of severely damaged primary anterior teeth. Materials and Methods: In this in vitro experimental study, 45 primary anterior teeth were randomly divided into three groups. After root canal preparation, the canals were filled with Metapex paste such that after the application of 1 mm of light-cure liner, 3 mm of the coronal third of the canal remained empty for composite post fabrication. Filtek Z250 conventional composite was used in group 1, Sonic-Fill bulk-fill composite was used in group 2 and Sonic-Fill with one layer of Filtek Z250 as the veneering were used in group 3. Adper Single Bond 2 was used in all groups. The teeth were thermocycled, and fracture resistance was measured by a universal testing machine. The mode of fracture was categorized as repairable or irreparable. Data were analyzed using one-way ANOVA. Results: The mean fracture resistance was 307.00±74.72, 323.31±84.28 and 333.30±63.96 N in groups 1 to 3, respectively (P=0.55). The mean fracture strength was 14.53±2.98, 15.08±2.82 and 15.26±3.02 MPa in groups 1 to 3, respectively (P=0.77). The frequency of repairable mode of failure was 80% for the conventional, 73.6% for the bulk-fill and 80% for the bulk-fill plus conventional group, with no significant difference (P>0.05). Conclusions: Bulk-fill composites can be used for coronal reconstruction of severely damaged primary anterior teeth similar to conventional composites to decrease the treatment time in pediatric patients.

scholarly journals Fracture resistance of veneers in premolars

2018 ◽  
Vol 12 (02) ◽  
pp. 191-198 ◽  
Author(s):  
Ludmilla Azevedo Linhares ◽  
Larissa Fernanda Pottmaier ◽  
Guilherme Carpena Lopes
Keyword(s):  
Fracture Resistance ◽  
Composite Resin ◽  
Lithium Disilicate ◽  
Mean Values ◽  
Significant Difference ◽  
Mode Of Failure ◽  
The Mean ◽  
Tooth Preparation ◽  
Post Hoc ◽  
One Way Anova

ABSTRACT Objective: The purpose of the study was to compare the fracture resistance of ceramic veneers and composite resin veneers with and without dental preparation. Materials and Methods: Forty freshly extracted mandibular premolars were selected and randomly assigned into four groups (n = 10): Group NPR = no dental preparation and direct veneer with 0.2 mm thick composite resin (Amelogen Plus, Ultradent); Group NPC = no dental preparation and 0.2 mm thick lithium disilicate ceramic veneer (IPS e.max Press, Ivoclar Vivadent); Group P2C = Tooth preparation of 0.2 mm and 0.2 mm thick ceramic veneer (IPS e.max Press); and Group P5C = Tooth preparation of 0.5 mm and 0.5 mm-thick ceramic veneer (IPS e.max Press). In all groups, the restorations covered 1 mm of the occlusal surface of the buccal cusp, and the thickness of this area was the same of the buccal area (0.2 mm or 0.5 mm). After the luting procedure, all groups were thermocycled (10,000 cycles, 5°C–55°C) and subjected to fracture resistance test under compression (Instron 4444 with a crosshead speed of 0.5 mm/min). The mode of failure analysis was performed under a ×10 magnification. Data were subjected to one-way ANOVA and Duncan's post hoc test (P < 0.05). Results: The mean fracture resistance (men ± standard deviation) was NPR = 690.33 ± 233, NPC = 790.52 ± 408, P2C = 1131.34 ± 341, and P5C = 983.56 ± 202. There were significant differences of the fracture resistance values between all groups (P = 0.013). NPR and NPC groups showed mean values of fracture resistance significantly lower than P2C. However, P5C presented intermediate values without a significant difference from the other groups. The mode of failure for all groups was mixed (60%), cohesive failures (20%), root failures (15%), and adhesive failures (5%). Conclusion: Minimally invasive tooth preparation (0.2-mm) allowed to achieve higher fracture resistance in premolars restored with lithium disilicate ceramic veneers. Attention should be given to the 0.5 mm preparation since catastrophic fractures only happened when this preparation depth was performed.

scholarly journals Effects of prophylactic ketamine and pethidine to control postanesthetic shivering: A comparative study

2018 ◽  
Vol 5 (12) ◽  
pp. 2898-2903 ◽  
Author(s):  
Masoum Khoshfetrat ◽  
Ali Rosom Jalali ◽  
Gholamreza Komeili ◽  
Aliakbar Keykha
Keyword(s):  
Normal Saline ◽  
Pearson Correlation ◽  
Saline Group ◽  
Normal Saline Group ◽  
Chi Square ◽  
Double Blind ◽  
Postanesthetic Shivering ◽  
Significant Difference ◽  
The Mean ◽  
One Way Anova

Background: Shivering is an undesirable complication following general anesthesia and spinal anesthesia, whose early control can reduce postoperative metabolic and respiratory complications. Therefore, this study aims to compare the effects of prophylactic injection of ketamine and pethidine on postoperative shivering. Methods: This double-blind clinical trial was performed on 105 patients with short-term orthopedic and ENT surgery. The patients were randomly divided into three groups; 20 minutes before the end of the surgery, 0.4 mg/kg of pethidine was injected to the first group, 0.5 mg/kg of ketamine was injected to the second group, and normal saline was injected to the third group. After the surgery, the tympanic membrane temperature was measured at 0, 10, 20, and 30 minutes. The shivering was also measured by a four-point grading from zero (no shivering) to four (severe shivering). Data were analyzed by one-way ANOVA, Kruskal Wallis, Chi-square and Pearson correlation. Results: The mean age of patients was 35.8+/-11.45 years in the ketamine group, 34.8+/-11.64 years in the normal saline group, and 33.11+/-10.5 years in the pethidine group. The one-way ANOVA showed no significant difference in the mean age between the three groups (P=0.645). The incidence and intensity of shivering were significantly higher in the normal saline group than in the ketamine and pethidine groups (p=0.001). However, there was no significant difference in the incidence and the intensity of shivering between the ketamine and the pethidine groups (p=0.936). Conclusion: The results showed that the 0.5 mg/kg of ketamine could control the post-anesthetic shivering.  

scholarly journals Comparison of electrocardiographic parameters of racing and non-racing horses in Sokoto Nigeria

2020 ◽  
Vol 18 (1) ◽  
pp. 33-38
Author(s):  
B. Saidu ◽  
A.J. Ishaq ◽  
H.M. Ibrahim ◽  
A. Dahiru ◽  
A.M. Abdullahi ◽  
...  
Keyword(s):  
Standing Position ◽  
P Wave ◽  
Average Weight ◽  
T Wave ◽  
Qt Intervals ◽  
Significant Difference ◽  
The Mean ◽  
Electrocardiographic Parameters ◽  
Electrical Activities ◽  
One Way Anova

The study was conducted due to the economic importance of horses and shortage of information on electrocardiographic parameters of horses in Sokoto, Nigeria. This study established the normal electrocardiographic parameters of racing and non-racing horses in Sokoto and statistically compared the values. The study used forty horses comprising of 20 racing and 20 non-racing horses with mean age of 8 ± 0.5 years and average weight of 200 ± 2.0 kg. ECG was recorded using the base apex system with the animals in standing position using single lead channel ECG recorder (EDAN VE-100 manufactured by Edan instruments China). The paper speed was set at 25mm/s while the sensitivity of the machine was adjusted to 10 mm/mV. The durations and amplitudes of P, R and T, the durations of Q and S and the durations of PR, QRS and QT intervals were all determined. These parameters were determined for the three standard limb leads (I, II and III) as well as the augmented limb leads (aVR, aVL and aVF). Descriptive statistics using SPSS version 16 was used to calculate the means and standard error of mean at 95 % confidence interval. One-way ANOVA was used to compare between the values of the racing and non-racing horses. The highest values of P amplitude, R amplitude, Q amplitude, QRS complex and P-R interval were recorded in racing horses, while highest T wave amplitude was recorded in non-racing horses. Highest duration of P wave, T wave and QRS was recorded in racing horses while highest duration of Q wave was recorded in non-racing horses. Significant difference was found in the T amplitude in racing horses in lead aVF. The mean heart rate for the racing and non-racing horses was 80.3 ± 8.4 and 63.1 ± 9.2 beats/minute respectively. Higher values recorded in racing horses indicates that exercise has influence on electrical activities in horses. Keywords: Electrocardiograph, Non-racing horses, Parameters, Racing horses, Sokoto

Are Internal Medicine Residents Meeting the Bar? Comparing Resident Knowledge and Self-Efficacy to Published Palliative Care Competencies

2020 ◽  
pp. 104990912095480
Author(s):  
Kristen M. Moyer ◽  
Matthew S. Ellman ◽  
John Encandela ◽  
Laura J. Morrison
Keyword(s):  
Internal Medicine ◽  
Palliative Care ◽  
Self Efficacy ◽  
Rank Analysis ◽  
Cultural Aspects ◽  
Internal Medicine Residents ◽  
Significant Difference ◽  
New Instrument ◽  
The Mean ◽  
One Way Anova

Background: There is a need for improved primary palliative care (PC) education and resident comfort with providing end-of-life care. Objective: Utilize a new instrument derived from published PC competencies to assess baseline Internal Medicine (IM) resident knowledge and self-efficacy in PC to identify educational gaps and create new PC curricula. Design: We created a 2-part instrument including a Knowledge Test (KT) and a Self-Efficacy Inventory (SEI) addressing 18 PC resident competencies across 5 domains: Pain and Symptom Management (PSM), Communication (COMM), Psychosocial, Spiritual, and Cultural Aspects of Care (PSC), Terminal Care and Bereavement (TCB), and Palliative Care Principles and Practice (PCPP). Setting/Subjects: The instrument was emailed to IM residents at our institution during academic years 2015-2016 and 2016-2017. Measurements: Basic descriptive statistics were performed for the KT and SEI. Mean Rank Analysis and One-way ANOVA were utilized for the KT and SEI, respectively. Congruence was calculated between knowledge and self-efficacy. Results: The mean score on the KT was 73% (range 33-80%). There was no significant difference in knowledge among post-graduate year cohorts. Self-efficacy scores were lower for interns overall and in PCPP, TCB, and COMM domains. Knowledge was concordant with self-efficacy in 42% of participants, higher than self-efficacy in 10% of participants, and lower than self-efficacy in 48% of participants. Conclusions: For approximately half of respondents, high self-efficacy in PC did not correlate with high PC knowledge. A more focused curriculum is needed to help IM residents facilitate mastery of PC competencies by graduation.

The Effect of Thermoforming on Tear Strength of Ethylene Vinyl Acetate Mouthguard Material in Various Thicknesses

2017 ◽  
Vol 751 ◽  
pp. 657-662
Author(s):  
Phakphum Srinuan ◽  
Jeerapatr O. Baiyokvichit ◽  
Rasana Boonpeng ◽  
Tanapol Wongwisatekit ◽  
Pacharaporn Pattanasukwasan ◽  
...  
Keyword(s):  
Vinyl Acetate ◽  
Testing Machine ◽  
Ethylene Vinyl Acetate ◽  
Strength Test ◽  
Tear Strength ◽  
Universal Testing ◽  
Significant Difference ◽  
The Mean ◽  
Thermoforming Process ◽  
One Way Anova

The effect of thermoforming on the tear strength of ethylene vinyl acetate (EVA) mouthguard material (Bioplast®) has not been widely investigated. The present study compared the tear strengths of non-processed and processed EVA specimens in various thicknesses. Two groups of EVA sheet (non-processed and processed) in three different thicknesses of 3, 4 and 5 mm were used in specimen fabrication. The processed EVA sheets were achieved by forming the EVA sheet on the cylindrical stone model with the pressure-molding device (Biostar®). Twelve of tear strength specimens of non-processed and processed group in each thickness were prepared following the modified ASTM D 624-00 guideline. The tear strength test was conducted using universal testing machine (Lloyd® 1K series) with the speed of 500 mm/min. The mean thickness and tear strength of the non-processed and processed specimens in each thickness were compared using independent T-test. The differences in the mean tear strength for each thickness of non-processed and process specimens were determined using one-way ANOVA. The mean tear strength and mean thickness of processed EVA specimens was significantly lower than the non-processed EVA specimens for every thickness (P ≤ 0.05). There was no significant difference in the mean tear strength of EVA specimens among each thickness in both non-processed and processed groups. It can be concluded that the thermoforming process has the significant effect on the tear strength of the EVA mouthguard material formed by pressure molding device in every thicknesses. The tear strength of processed specimens were significant lower than the non-processed. Thus, it is more relevant for testing properties of the processed mouthguard material that the mouthguard material before processing.

scholarly journals Influence of Sealing of the Screw Access Hole on the Fracture Resistance of Implant-Supported Restorations

2016 ◽  
Vol 27 (2) ◽  
pp. 148-152 ◽  
Author(s):  
Rodrigo de Paula Pereira ◽  
Cibele Oliveira de Melo Rocha ◽  
José Maurício dos Santos Nunes Reis ◽  
João Neudenir Arioli-Filho
Keyword(s):  
Fracture Resistance ◽  
Resin Composite ◽  
Filling Material ◽  
Ceramic Surface ◽  
Access Hole ◽  
Mandibular Molar ◽  
Significant Difference ◽  
Metal Ceramic ◽  
One Way Anova ◽  
Ceramic Implant

Abstract The purpose of this study was to assess the influence of sealing of the screw access hole (SAH) on the fracture resistance of metal-ceramic implant-supported restorations. UCLA abutments were used to make 30 implant-retained mandibular molar restorations and divide equally into three groups: Group SRS: screw-retained restorations with SAH sealed; Group SRNS: screw-retained restorations with SAH not sealed; Group CR: cement-retained restorations. The following protocol was adopted to restore the SAH: the ceramic surface of the SAH was air-abraded with aluminum oxide; etched with 10% hydrofluoric acid; a silane coupling agent and a bonding agent were applied; cotton pellets were used as filling material and P-60 resin composite as restoring material. The cement-retained restorations were cemented with Rely-X U100. A metal rod with a spherical tip of 6.0 mm diameter was used to apply a vertical static load, simultaneously on the buccal and lingual incline cusps, at a crosshead speed of 0.5 mm/min until the fracture of the specimens. Data were analyzed using one-way ANOVA and Dunnet test (p<0.05) for multiples comparisons. The mode of failure was evaluated by a scanning electron microscopy (SEM). No significant difference between screw-retained restorations was found. The highest mean fracture resistance values were observed with CR group. Therefore, it was shown that SAH sealing did not influence the fracture resistance of the screw-retained restorations.

scholarly journals An analysis of student's attitudes towards physical educationObez öğrencilerin beden eğitimi dersine karşı tutumlarının incelenmesi

2018 ◽  
Vol 15 (4) ◽  
pp. 2493
Author(s):  
Emre Çavdar ◽  
Ekrem Levent İlhan ◽  
Oguz Kaan Esentürk
Keyword(s):  
High School ◽  
High School Students ◽  
Secondary Education ◽  
Physical Education ◽  
School Students ◽  
Significant Difference ◽  
Kolmogorov Smirnov ◽  
The Mean ◽  
Students Attitudes ◽  
One Way Anova

In this study, it is aimed to analyze attitudes of obese students in high school towards physical education according to some variables. 74 secondary education student, 45 of them are girls and 29 boys who studied at three different Anatolian High Schools in the city of Niğde in the 2016-2017 academic year, have been participated in this study. As data collection tool, Physical Education attitude scale for secondary education students developed by Güllü and Güçlü (2009) has been used and coefficient of consistence (Cronbach Alpha) is 0,94. SPSS 23.0 packaged software has been used for assesing the result. Kolmogorov – Smirnov Test have been done regarding whether the data showed normal distribution or not and Kurtosis and Skewness values have been studied. Independent Sample T Test has been used to test the mean difference significance belonging to two group independent variables in the study. One Way ANOVA Test has been used to test the mean differences significence when the number of groups is more than two. At the end of the study, all of the attitude scores belonging to variables have been found high and it has been established that obese high school students’ attitudes towards Physical Education show statictically significant difference, according to gender, in favor of boys (p<0,05). Accordingly, it has been determined that students’ cognitive attitudes acording to obesity level for Physical Education show difference in favor of second grade obese students (p<0,05) and no significent difference found in students’ affective and behavioural attitudes (p>0,05). It has been identified that high school students’ attitudes towards Physical Education show no statistically significant difference according to their calass level variable and time variable which they spent with their communication instruments (p>0,05) As a result, when considering obese students’ positive attitudes towards physical education and sports, in view of obtained findings, it is possible to say that physical education and sports may contribute to increase the participation of obese students and thus make them become healthy individuals.Extended English summary is in the end of Full Text PDF (TURKISH) file. ÖzetBu araştırmada, lise düzeyinde öğrenim gören obez öğrencilerin beden eğitimi dersine yönelik tutumlarının bazı değişkenlere göre incelenmesi amaçlanmıştır. Araştırmaya 2016-2017 eğitim-öğretim yılında Niğde ilinde bulunan üç ayrı Anadolu Lisesi'nde öğrenim gören 45 kız ve 29 erkek olmak üzere toplam 74 lise öğrencisi katılmıştır. Araştırmada veri toplama aracı olarak Güllü ve Güçlü (2009) tarafından geliştirilen "Ortaöğretim Öğrencileri İçin Beden Eğitimi Dersi Tutum Ölçeği Kullanılmış olup ölçeğin iç tutarlılık katsayısı 0.94 olarak tespit edilmiştir. Verilerin değerlendirilmesinde SPSS 23.0 paket programı kullanılmıştır. Verilerin normal dağılım gösterip göstermediğine ilişkin Kolmogorov-Smirnov Testi yapılmış, Kurtosis ve Skewness değerleri incelenmiştir. Araştırmadaki iki gruplu bağımsız değişkenlere ait ortalama farkların anlamlılığını test etmek için parametrik hipotez testlerinden Independent Sample t testi kullanılmıştır. Grup sayısının ikiden fazla olduğu durumlarda gruplar arasındaki ortalama farklarının anlamlılığını test etmek için ise, One Way ANOVA testi kullanılmıştır. Araştırmanın sonunda, değişkenlere ait tutum puanlarının hepsi yüksek bulunmuş olup, liselerde öğrenim gören obez öğrencilerin beden eğitimi dersine yönelik tutumlarının cinsiyete göre istatistiksel olarak erkekler lehine anlamlı farklılık gösterdiği tespit edilmiştir (p<0.05). Benzer şekilde öğrencilerin beden eğitimi dersine yönelik obezite düzeyine göre bilişsel tutumlarının 2. sınıf obez öğrenciler lehine anlamlı farklılık gösterdiği belirlenmiş olup (p<0.05), duyuşsal ve davranışsal tutumlarında anlamlı farklılık bulunmamıştır (p>0.05). Öğrencilerin beden eğitimi dersine yönelik tutumlarının öğrenim gördükleri sınıf düzeyine  ve iletişim araçları ile geçirdileri süre değişkenine göre istatistiksel olarak anlamlı farklılık göstermediği belirlenmiştir (p>0.05). Sonuç olarak, obez öğrecilerin beden eğitimi ve spor derslerine karşı tutumlarının olumlu olduğu göz önünde bulundurulduğunda elde edilen bulguların beden eğitimi ve spor derslerinin obez öğrencilerin spora katılımının arttırılması ve dolayısıyla onların sağlıklı bireyler olmalarında önemli düzeyde katkısının olabileceğini söylemek mümkündür

scholarly journals Fracture Resistance and Strain Analysis of Zirconia Copings With Vertical Knife Edge and Three Horizontal Finish Line Designs; Chamfer, Deep Chamfer and Shoulder With Two Cementation Techniques

2021 ◽  
Vol 24 (4) ◽  
Author(s):  
Marwa Emam ◽  
Amr El-Etreby ◽  
Jihan Farouk Younis
Keyword(s):  
Fracture Resistance ◽  
Testing Machine ◽  
Tetragonal Zirconia ◽  
Resin Cement ◽  
Knife Edge ◽  
Glass Ionomer ◽  
Finish Line ◽  
Promising Alternative ◽  
Significant Difference ◽  
Mean Strain

Objective: The purpose of this in vitro study is to evaluate the effect of four finish line configurations and two cement types on the fracture resistance of zirconia copings. Material and Methods: Forty yttrium tetragonal zirconia polycrystals copings were manufactured on epoxy resin dies with four preparation designs: knife edge, chamfer, deep chamfer 0.5, 1 mm and shoulder 1 mm. The copings were cemented with two cement types (glass ionomer and resin cement); (n = 5). Two strain gauges were attached on each coping before they were vertically loaded till fracture with a universal testing machine. Data were analyzed by 2-way analysis of variance ANOVA (p < .05). Fractured specimens were examined for mode of failure with digital microscope. Results: Knife edge showed the highest mean fracture resistance (987.04 ± 94.18) followed by Chamfer (883.28 ± 205.42) followed by Shoulder (828.64 ± 227.79) and finally Deep chamfer finish line (767.66 ± 207.09) with no statistically significant difference. Resin cemented copings had higher mean Fracture resistance (911.76 ± 167.95) than glass ionomer cemented copings (821.55 ± 224.24) with no statistically significant difference. Knife edge had the highest strain mean values on the buccal (374.04 ± 195.43) and lingual (235.80 ± 103.46) surface. Shoulder finish line showed the lowest mean strain values on the buccal (127.47 ± 40.32) and lingual (68.35 ± 80.68) with no statistically significant difference. Resin cemented copings had higher buccal (295.05 ± 167.92) and lingual (197.38 ± 99.85) mean strain values  than glass ionomer copings (149.14 ± 60.94) and (90.27 ± 55.62) with no statistically significant difference. Conclusion: Vertical knife edge finish line is a promising alternative and either adhesive or conventional cementation can be used with zirconia copings.   KEYWORDS Cementation; Flexural strength; Prosthodontics; Tooth preparation; Zirconium.

scholarly journals Microshear Bond Strength of Resin Cements to Lithium Disilicate Substrates as a Function of Surface Preparation

2015 ◽  
Vol 40 (5) ◽  
pp. 524-532 ◽  
Author(s):  
DP Lise ◽  
J Perdigão ◽  
A Van Ende ◽  
O Zidan ◽  
GC Lopes
Keyword(s):  
Bond Strength ◽  
Surface Treatment ◽  
Lithium Disilicate ◽  
Resin Cement ◽  
Resin Cements ◽  
Relyx Unicem ◽  
Significant Difference ◽  
The Mean ◽  
Microshear Bond Strength ◽  
Silane Solution

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&lt;0.05). Results When means were pooled for the factor surface treatment, HF resulted in a significantly higher μSBS than did NT (p&lt;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&lt;0.001). Considering the factor resin cement, Variolink II resulted in a significantly higher mean μSBS than did RelyX Unicem 2 (p&lt;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&lt;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.

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