scholarly journals Retention of different temporary cements tested on zirconia crowns and titanium abutments in vitro

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Felix Dähne ◽  
Heike Meißner ◽  
Klaus Böning ◽  
Christin Arnold ◽  
Ralf Gutwald ◽  
...  
Keyword(s):  
Fracture Mode ◽  
Testing Machine ◽  
Mode Analysis ◽  
Chi Square ◽  
Retention Force ◽  
Luting Agents ◽  
Implant Abutments ◽  
Before And After ◽  
Zirconia Crowns

Abstract Purpose The aim of the present study was to examine the retention force of monolithic zirconia copings cemented with various temporary cements on implant abutments in vitro. Methods Sixty exercise implants with pre-screwed implant abutments were embedded in resin. Subsequently, 60 CAD/CAM manufactured zirconia copings were divided into three main groups [Harvard Implant Semi-permanent (HAV), implantlink semi Forte (IMP), Temp Bond NE (TBNE)]. The zirconia copings were cemented on the implant abutments and loaded with 35 N. Specimens were stored in distilled water (37 °C) for 24 h. Half of the test specimens of each group were subjected to a thermocycling (TC) process. Retention force was measured in a universal testing machine. Using magnifying glasses, the fracture mode was determined. Statistical analysis was performed applying the Kruskal-Wallis test, the post hoc test according to Dunn-Bonferroni and a chi-square test of independence. Results Without TC, IMP showed the highest retention of the three temporary luting agents (100.5 ± 39.14 N). The measured retention forces of IMP were higher than those of HAV (45.78 ± 15.66 N) and TBNE (61.16 ± 20.19 N). After TC, retention was reduced. IMP showed the greatest retentive strength (21.69 ± 13.61 N, three fail outs). HAV and TBNE showed pull-off forces of similar magnitude (17.38 ± 12.77 N and 16.97 ± 12.36 N, two fail outs). The fracture mode analysis showed different results regarding the tested cements before and after TC (facture type before/after TC): IMP (III+II/III), HAV (I/II) and TBNE (III/III). There were clear differences of the fracture modes regarding the examination before and after TC. Conclusions Within the limits of this study, IMP showed the highest pull-off forces under the chosen test conditions. All three temporary luting agents showed lower retention forces after TC. Retention values in the individual cement classes were very heterogeneous. Easy cement removal in the crown lumen favours the dominance of adhesive cement fractures on the abutment and adhesive/cohesive cement fractures on the abutment with HAV appears advantageous in case of recementation of the superstructure.

scholarly journals In Vitro Fit and Cementation Resistance of Provisional Crowns for Single Implant-Supported Restorations

2015 ◽  
Vol 26 (5) ◽  
pp. 468-473 ◽  
Author(s):  
Izabela Cristina Maurício Moris ◽  
Juliana Elias de Oliveira ◽  
Adriana Cláudia Lapria Faria ◽  
Ricardo Faria Ribeiro ◽  
Renata Cristina Silveira Rodrigues
Keyword(s):  
Film Thickness ◽  
Methyl Methacrylate ◽  
Calcium Hydroxide ◽  
Testing Machine ◽  
Mixed Linear Model ◽  
Marginal Fit ◽  
Luting Agents ◽  
Mechanical Cycling ◽  
Before And After

Abstract: This study aimed to verify marginal fit and the effect of cement film thickness standardization on retention of provisional crowns made with prefabricated acrylic cylinders on abutments, using two temporary luting agents subjected or not to mechanical cycling. Provisional crowns were made from bis-acryl (Luxatemp Fluorescence) or methyl methacrylate (Duralay) resins on acrylic cylinders and marginal fit and cement film thickness were evaluated. For retention evaluation, crowns were cemented with two temporary luting agents: non-eugenol zinc oxide (Tempbond NE) or calcium hydroxide-based (Hydcal) cements and subjected to tensile strength in a universal testing machine. After cleaning, debonded crowns were cemented again, subjected to mechanical cycling and retention was reassessed. The results of marginal fit and cement film thickness were analyzed by Student's t-test while retention of cements before and after mechanical cycling was analyzed using a mixed linear model. Methyl methacrylate crowns presented greater marginal misfit (p=0.001) and occlusal cement film thickness (p=0.003) than the bis-acryl ones. No difference was observed at axial cement film thickness (p=0.606). Resins (p=0.281) did not affect crown retention, but luting agents (p=0.029) and mechanical cycling (p=0.027) showed significant effects. The only significant interaction was mechanical cycling*luting agents, which means that luting agents were differently affected by mechanical cycling (p=0.002). In conclusion, the results showed that bis-acryl resin associated to calcium-hydroxide luting agent provided the best retention and lower cement thickness.

scholarly journals 252 COMPARISON OF TWO SPERM SEPARATION PRODUCTS FOR USE IN BOVINE IVF

2005 ◽  
Vol 17 (2) ◽  
pp. 276 ◽  
Author(s):  
J. Pryor ◽  
S. Romo ◽  
D.D. Varner ◽  
K. Hinrichs ◽  
C.R. Looney
Keyword(s):  
Sperm Concentration ◽  
Embryo Production ◽  
Chi Square ◽  
Vitro Fertilization ◽  
Before And After ◽  
Chi Square Test ◽  
Group 2 ◽  
Live Sperm ◽  
Sperm Separation

In commercial bovine in vitro fertilization (IVF) companies, there is a continuous need to improve results. Efforts to maximize in vitro embryo production have included modifications in the use of sperm separation gradients. The development of commercially available sperm centrifugation gradients represents a new possibility of increasing the number of viable sperm that can be obtained from low concentration (fresh or frozen, sexed or unsexed) semen samples in order to improve the efficiency of the IVF system to make embryo production as efficient as possible. The objective of this study was to compare two different separation gradients, as follows: Group 1: Percoll (Sigma, St. Louis, MO, USA), in 45% and 90% gradients; Group 2: EquiPure (Nidacon, Gathenburg, Sweden), in top and bottom layers. Before and after separation, sperm were evaluated at 200× magnification for total motility, and then stained to assess viability at 400× with fast-green/eosin stain (Sigma). Sperm separation was performed using frozen/thawed semen from one bull. Semen was separated by centrifugation at 200g for 30 min in both density gradients. Results obtained from Groups 1 and 2 were compared by chi-square test. Sperm separation with Percoll yielded lower numbers of sperm (average sperm concentration after separation of 92 × 106, vs. 159 × 106 sperm/mL for EquiPure; P < 0.05) but resulted in higher motility (60% vs. 39%, respectively; P < 0.05) of separated sperm. Rates of live sperm cells were not significantly different between groups (69.5% vs. 70%, respectively; P > 0.1). These results indicate that the commercial separation medium EquiPure may be associated with higher sperm concentration levels but with lowered sperm motility when compared to Percoll for bovine sperm separation. However, Equipure provided similar percentages of live sperm when compared to Percoll, which is currently used in our laboratory.

scholarly journals Influence of Luting Materials on the Retention of Cemented Implant-Supported Crowns: An In Vitro Study

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1853 ◽  
Author(s):  
Ella Naumova ◽  
Felix Roth ◽  
Berit Geis ◽  
Christine Baulig ◽  
Wolfgang Arnold ◽  
...  
Keyword(s):  
Artificial Saliva ◽  
In Vitro Study ◽  
Storage Conditions ◽  
Glass Ionomer Cements ◽  
Glass Ionomer ◽  
Cobalt Chromium ◽  
Retention Force ◽  
Implant Abutments ◽  
Aging Conditions

The retention force of cemented crowns on implant abutments with various luting materials was evaluated. Cobalt–chromium crowns were cemented onto tapered titanium abutments (Camlog) with eugenol-free temporary cement (RelyX TempBond NE), composite-based temporary cement (Bifix Temp), zinc phosphate cement (Harvard Cement), glass-ionomer cements (Meron, Fuji I), and resin-modified glass-ionomer cements (Fuji II, Fuji Plus, Ketac Cem Plus). Specimen aging via hydrostress was performed in artificial saliva at 37 °C for 14 days (S1), followed by hydrothermal stress with thermocycling (S2). The crowns were removed, and the force was recorded (T1). Subsequently, the crowns were recemented, aged, and removed, and the force was recorded (T2, T3). The retention forces differences were statistically significant according to the storage conditions at T1 (p = 0.002) and T3 (p = 0.0002). After aging (S1), Ketac Cem Plus had the highest retention force median value difference (T3 versus T1) (−773 N), whereas RelyX TempBond NE had the lowest (−146 N). After aging (S2), Meron had the highest retention force median value difference (−783 N), whereas RelyX TempBond NE had the lowest (−168 N). Recementation decreased the retention force of the implant-supported cobalt–chromium crowns cemented and recemented with the same luting materials. Luting materials (at T1) and aging conditions significantly impacted the retention force.

scholarly journals Fracture Resistance of Primary Molars Restored with Endocrowns Versus Zirconia Crowns (An in Vitro Study)

2021 ◽  
Vol 24 (4) ◽  
Author(s):  
Ayman Sabbah ◽  
Mostafa Kamel
Keyword(s):  
Fracture Resistance ◽  
Testing Machine ◽  
In Vitro Study ◽  
Composite Resins ◽  
Primary Molars ◽  
P Value ◽  
Pulp Chamber ◽  
Group I ◽  
Zirconia Crowns

Objective: This study aimed to assess the fracture resistance of primary molars restored with endocrowns compared to prefabricated zirconia crowns. Methods: Twelve sound, defect-free primary second molars were selected and divided into two groups: group I included 6 molars restored with zirconia crowns, while group II included 6 teeth restored with endocrowns. For both groups access cavity was prepared for the teeth to open pulp chamber. Fracture resistance of both groups was tested using a universal testing machine. Results: Zirconia crown showed statistically significantly higher mean fracture resistance than Endocrown (P-value = 0.001, Effect size = 2.72). Conclusion: Pulpotomized primary molars restored with Zirconia crowns showed significantly higher mean fracture resistance compared to primary molars restored with endocrowns, meanwhile both restorations have shown higher mean fracture resistance than the maximum biting force in children. Keywords  Composite resins; Endocrown; Fracture strength; Zirconia crowns.

Effect of Luting Agents on Retention of Dental Implant-Supported Prostheses

2015 ◽  
Vol 41 (5) ◽  
pp. 596-599 ◽  
Author(s):  
Yu-Hwa Pan ◽  
Tai-Min Lin ◽  
Perng-Ru Liu ◽  
Lance C. Ramp
Keyword(s):  
Dental Implant ◽  
Zinc Phosphate ◽  
Failure Load ◽  
Testing Machine ◽  
In Vitro Study ◽  
Range Analysis ◽  
Luting Agents ◽  
Luting Cement ◽  
Implant Abutment

To evaluate the retentive strength of 7 different luting agents in cement-retained implant abutment/analog assemblies. Fifty-six externally hexed dental implant abutment/analog assemblies and cast superstructures were divided randomly into 7 groups for cementation with each of the 7 luting agents. Five definitive cements tested were zinc phosphate cement, All-Bond 2, Maxcem, RelyX Luting cement, HY-Bond, and two provisional cements, ImProv and Premier. Cast superstructures were cemented onto the implant abutments and exposed to 1000 thermal cycles (0°C–55°C) and 100 000 cycles on a chewing simulator (75 N load). A universal testing machine was used to measure cement failure load of the assembled specimens. Cement failure load was evaluated with 1-way ANOVA and Duncan's multiple range analysis. Significant differences in cement failure loads were measured (P &lt; .0001). Post hoc testing with Duncan's multiple range indicated 4 separate groupings. Maxcem and All-Bond 2 were comparable, having the greatest load failure. RelyX and zinc phosphate cement were analogous, and higher than HY-Bond. Improv and Premier constituted a pair, which demonstrated the lowest retentive values. Within the limitations of this in vitro study, Maxcem and All-Bond 2 are good candidates for cement-retained implant prostheses while concerning retention.

scholarly journals Retention Strength after Compressive Cyclic Loading of Five Luting Agents Used in Implant-Supported Prostheses

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Angel Alvarez-Arenal ◽  
Ignacio Gonzalez-Gonzalez ◽  
Hector deLlanos-Lanchares ◽  
Aritza Brizuela-Velasco ◽  
Javier Pinés-Hueso ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Resin Composite ◽  
Testing Machine ◽  
Compressive Load ◽  
Tensile Tests ◽  
Clinical Situation ◽  
Glass Ionomer ◽  
Luting Agents ◽  
Before And After ◽  
Retention Strength

The purpose of this study was to evaluate and compare the retention strength of five cement types commonly used in implant-retained fixed partial dentures, before and after compressive cyclic loading. In five solid abutments screwed to 5 implant analogs, 50 metal Cr-Ni alloy copings were cemented with five luting agents: resin-modified glass ionomer (RmGI), resin composite (RC), glass ionomer (GI), resin urethane-based (RUB), and compomer cement (CC). Two tensile tests were conducted with a universal testing machine, one after the first luting of the copings and the other after 100,000 cycles of 100 N loading at 0.72 Hz. The one way ANOVA test was applied for the statistical analysis using the post hoc Tukey test when required. Before and after applying the compressive load, RmGI and RC cement types showed the greatest retention strength. After compressive loading, RUB cement showed the highest percentage loss of retention (64.45%). GI cement recorded the lowest retention strength (50.35 N) and the resin composite cement recorded the highest (352.02 N). The type of cement influences the retention loss. The clinician should give preference to lower retention strength cement (RUB, CC, and GI) if he envisages any complications and a high retention strength one (RmGI, RC) for a specific clinical situation.

Fracture Resistance of Implant Abutments Following Abutment Alterations by Milling the Margins: An In Vitro Study

2016 ◽  
Vol 42 (6) ◽  
pp. 464-468 ◽  
Author(s):  
Anuya Patankar ◽  
Mohit Kheur ◽  
Supriya Kheur ◽  
Tabrez Lakha ◽  
Murtuza Burhanpurwala
Keyword(s):  
Fracture Resistance ◽  
Testing Machine ◽  
In Vitro Study ◽  
Vitro Study ◽  
Maximum Resistance ◽  
Universal Testing ◽  
Implant Abutments ◽  
Implant Abutment ◽  
Different Levels

This in vitro study evaluated the effect of different levels of preparation of an implant abutment on its fracture resistance. The study evaluated abutments that incorporated a platform switch (Myriad Plus Abutments, Morse Taper Connection) and Standard abutments (BioHorizons Standard Abutment, BioHorizons Inc). Each abutment was connected to an appropriate implant and mounted in a self-cured resin base. Based on the abutment preparation depths, 3 groups were created for each abutment type: as manufactured, abutment prepared 1 mm apical to the original margin, and abutment prepared 1.5 mm to the original margin. All the abutments were prepared in a standardized manner to incorporate a 0.5 mm chamfer margin uniformly. All the abutments were torqued to 30 Ncm on their respective implants. They were then subjected to loading until failure in a universal testing machine. Abutments with no preparation showed the maximum resistance to fracture for both groups. As the preparation depth increased, the fracture resistance decreased. The fracture resistance of implant abutment junction decreases as the preparation depth increases.

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