scholarly journals Evaluation of removal torque values for titanium screws of prosthetic abutments after different torque application techniques: in vitro study

2016 ◽  
Vol 19 (4) ◽  
pp. 12
Author(s):  
Carolina Enith Bullen Medina ◽  
Caroline Freitas Rafael ◽  
Claudia Angela Maria Volpato ◽  
Mutlu Özcan ◽  
Diego Klee de Vasconcelos
Keyword(s):  
Testing Machine ◽  
In Vitro Study ◽  
Removal Torque ◽  
Titanium Screws ◽  
Application Techniques ◽  
Group 3 ◽  
Group 2 ◽  
Torque Values ◽  
Group 1

<p class="Corpo"><strong>Objective:</strong> To evaluate the removal torque values on abutment screws after different torque application techniques. <strong>Materials and methods:</strong> Thirty specimens of an external hexagon implant, a prefabricated abutment and a titanium screw were distributed randomly in three groups. In group 1, the screws received a torque of 30 N.cm; group 2 received a torque of 30N.cm and a second torque after 10 min, in accordance with the technique proposed by Brending et al. and Dixon et al.; in group 3, a torque of 30 N.cm was applied and maintained for 20 s, in accordance with the technique recommended by Sella et al. The specimens were attached to a universal testing machine and a digital key was coupled to the load cell in order to control the torque value at a velocity of 1 N.cm/s. Removal torque was performed 10 minutes after torque application. Values were statistically analysed using one-way ANOVA and Tukey’s HSD test (α = 0.05). <strong>Results:</strong> The mean and standard deviations (±SD) of removal torque values found were 27.95±0.99N.cm for group 1, 28.32±0.68N.cm for group 2 and 26.89±1.03N.cm for group 3. Groups 1 and 2 exhibited statistically higher values of torque than group 3 (p ˂ 0.05). <strong>Conclusion:</strong> The technique recommended by Breeding et al. and Dixon et al. seemed to be the best option when considering the removal torque values of external hexagon implants.</p><p class="Corpo"> </p><p class="Corpo"><strong>Keywords<em>:</em></strong><strong> </strong>Abutment screw; Dental implants; Removal torque.<strong></strong></p>

scholarly journals Experimental Investigation of the Influence of Chlorhexidine Gel on the Implant-Abutment-Connection

2020 ◽  
Author(s):  
Lisa Mandlbauer ◽  
Vasilios Alevizakos ◽  
Ahmed Othman ◽  
Marcus Stoetzer ◽  
Constantin von See
Keyword(s):  
Testing Machine ◽  
In Vitro Study ◽  
Control Group ◽  
Removal Torque ◽  
Significance Level ◽  
Saliva Substitute ◽  
Group 3 ◽  
Group 2 ◽  
Chlorhexidine Gel

Abstract Background The aim of this study was to determine the effect of chlorhexidine gel on removal torque of abutment prosthesis screws in vitro. Methods 60 implants (BEGO Semados ® S/RI 4.1, BEGO Implant Systems GmbH & Co. KG, Bremen, Germany) were embedded in acrylic resin for study set-up. The abutments (S/RI 4.1 SUB-TEC WI, BEGO Implant Systems GmbH & Co. KG, Bremen, Germany) were fixed with prothesis screws with 25 Ncm on the implants and were loaded for 10.000 cycles with 250N in a static material testing machine. The implemented study consisted of three groups (n=20). Group 1 (control group) were loaded under dry conditions. Group 2 was filled with a saliva substitute only (Sialin-Sigma solution, Sigmapharm Arzneimittel GmbH, Vienna, Austria), group 3 was filled with a saliva substitute and additional with chlorhexidine gel (Chlorhexamed 1% GEL, GlaxoSmithKline Consumer Healthcare GmbH & Co. KG, München, Germany). Statistical analysis was performed using ANOVA (significance level p<0.05). Results The control group showed the smallest range of removal torque (19.85 Ncm ± 1.42 Ncm) while group 2 showed 20.32 Ncm ± 2.61 Ncm and in group 3 was 19.74 Ncm ± 2.96 Ncm. No significant differences between the three groups were evaluated. Conclusions Within the limits of this in-vitro study, it can be concluded that the application of chlorhexidine gel did not show any significant effect on the removal torque on abutment screws after loading.

scholarly journals Effect of Reinforcement on the Fracture Resistance of Endodontically Treated Molars by Various Bonded Restorations-An In Vitro Study

2015 ◽  
Vol 03 (02) ◽  
pp. 103-111
Author(s):  
Jaidev Dhillon ◽  
Sachin Passi ◽  
Ajay Chhabra ◽  
◽  
Keyword(s):  
Fracture Resistance ◽  
Resin Composite ◽  
Testing Machine ◽  
In Vitro Study ◽  
Group 4 ◽  
Significant Difference ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

Abstract Objective: To compare and evaluate the fracture resistance of endodontically treated molars reinforced with various bonded restorations and to study the type of fractures in various restorations. Methods: Forty extracted mandibular molars were endodontically treated. MOD (Mesio-Occluso-Distal) cavities were prepared and Mesio-Buccal cusp was reduced in all to provide cuspal coverage. All the teeth were then divided into 4 groups. The cavities in group 1(control) were filled with high copper amalgam. Group 2 was restored with direct resin composite. In group 3 after the priming and bonding procedures as in group 2, cavity surfaces were coated with flowable resin composite. Before curing a piece of polyethylene ribbon fiber was cut and coated with adhesive resin and was embedded inside the flowable composite. The resin composite was cured with visible light cure (VLC) gun. For group 4, restorations were done according to the recommendations provided by the manufacturers of SR Adoro (Ivoclar-Vivadent, Schaan, Liechtenstein) composite material. Compressive fracture strength test was performed after at least 24 hours of the fabrication of the specimens, by application of compressive loading in a Universal testing machine, applied on the occlusal aspect of each specimen with a steel bar. The mean loads necessary to fracture were recorded in Newton and the results were statistically analyzed. Results: Group 4 (indirect composite inlay) had the greater fracture resistance and group 1(Amalgam) had the poorest. Difference between group 1 and 3, group 1 and 4, group 2 and 4 were statistically significant. No statistically significant difference was found between group 1 and 2, group 2 and 3, group 3 and 4. Predominant type of fracture in group 1 and 3 was fracture of tooth below cemento enamel junction at tooth restoration interface without mesio buccal cusp involvement. In group 2 and 4, predominant fractures were of tooth below cemento enamel junction through center of restoration without mesio–buccal cusp involvement.

scholarly journals Comparative Evaluation of Cleaning Efficacy of Three Different Single File Systems: An In Vitro Study

2021 ◽  
pp. 26-31
Author(s):  
Deebah Choudhary
Keyword(s):  
File Systems ◽  
In Vitro Study ◽  
Single File ◽  
Working Length ◽  
Group 3 ◽  
Group 2 ◽  
Cleaning Efficacy ◽  
Scanning Electron ◽  
Group 1

Aim: The aim of this study was to evaluate the canal cleaning efficacy of these three file systems using scanning electron microscopy. Place and Duration of Study: The study was conducted in the Department of Conservative dentistry and Endodontics, Institute of Dental Sciences Sehora, between October 2020 and December 2020. Materials and Methods: Access cavity preparation was performed on sixty extracted human mandibular premolar teeth and working length was determined. The samples were randomly divided into three groups (n=20) depending upon the file system used i.e. Group 1 (Reciproc Blue), Group 2 (Waveone Gold) and Group 3 (F360). Samples were split into two halves by creating longitudinal grooves on the buccal and lingual surfaces. The samples were sputter-coated with gold and examined under scanning electron microscope at 5000X. The dentinal wall of root canal at coronal, middle and apical thirds of each sample were evaluated for the presence of determining the canal cleanliness and then analyzed using a five-score index. Results: The results of this study revealed that Group 1 (Reciproc Blue) exhibited better cleaning efficacy than samples of Group 2 (WaveOne Gold) and Group 3 (F360) at different locations in the canal i.e. coronal, middle and apical. The mean debris present was highest in coronal area for both group 2 and group 3 i.e. 2.1 and least was seen in apical area of group 1 i.e. 0.3. (p<0.05) Conclusion: Reciproc Blue single-file showed highest cleaning efficacy followed by Waveone Gold and F360. Reciproc file also showed effective cleaning in the apical third of the canal.

Evaluation of physical and adhesive properties of enamel after a therapeutic dose of radiation and bonding of orthodontic metal brackets: an in vitro study

2020 ◽  
pp. 1-5
Author(s):  
A. Anushree ◽  
Ashutosh Shetty ◽  
Crystal Runa Soans ◽  
M. N. Kuttappa ◽  
Akhil Shetty ◽  
...  
Keyword(s):  
Testing Machine ◽  
In Vitro Study ◽  
Tooth Surface ◽  
Control Group ◽  
Adhesive Properties ◽  
Adhesive Resin ◽  
Adhesive Remnant Index ◽  
Group 3 ◽  
Group 2

Abstract Aim: The study aimed to evaluate the shear bond strength (SBS) of metal brackets and adhesive properties of bonded irradiated and non-irradiated teeth. Methods: Sixty-six extracted premolar samples were randomly divided into three groups—(a) Control group consisting of 22 non-irradiated, non-aged teeth (Group 1), (b) 22 non-irradiated, aged samples (Group 2) and (c) 22 irradiated, aged samples (Group 3). Irradiation was done using gamma irradiation with a fractionated dose of 60 Gy for 5 consecutive days per week over 6 weeks. Metal brackets were bonded on all samples with light cure adhesive and subjected to SBS test using universal testing machine. The samples were assessed under the scanning electron microscope to check for the adhesive remnant index (ARI) and tag depth. Results: There was a statistically significant decrease in the mean SBS of the irradiated samples compared to the non-irradiated teeth. The non-irradiated, aged samples showed a majority of ARI scoring 1 and 2. Whereas, the irradiated samples showed ARI scoring 2 and 3. Approximately, 77·3% of the non-irradiated samples showed no adhesive present on the tooth surface, and 27·2% of the irradiated samples had more than 50% adhesive present on the enamel surface. Conclusion: There is a statistically significant decrease in SBS of irradiated enamel compared to that of non-irradiated teeth. However, the SBS observed in the three groups was well above the ideal SBS for orthodontic bonding, that is, 5·6–6·8 MPa. The adhesive remnant was found on all samples of the irradiated group. Deeper adhesive resin tags were found in the irradiated group in the resin–enamel interface.

scholarly journals A Comparative Evaluation of Three Commercially Available Dentin Desensitizers on the Shear Bond Strength of Composite Resins: An in vitro Study

2015 ◽  
Vol 5 (2) ◽  
pp. 65-68
Author(s):  
Shruti Patil ◽  
Prajna Shetty
Keyword(s):  
Bond Strength ◽  
Comparative Evaluation ◽  
Shear Bond Strength ◽  
In Vitro Study ◽  
Composite Resins ◽  
Group 4 ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

ABSTRACT Background The dentin desensitizers available for in-office application for prevention and/or treatment of post restorative dentinal hypersensitivity, act by blocking the open dentinal tubules. In doing so, they may influence the bond strength of the restorative resins. Thus, the aim of the study was to evaluate the effect of desensitizers on the shear bond strength of dentin adhesives and to check the extent of dentinal tubule occlusion caused by these desensitizers. Materials and Methods Sixty-four premolars were randomly divided into four groups of sixteen each. The middle depth dentin was exposed by on the buccal surface and was etched using 37% phosphoric acid and rinsed. They were assigned to, Group 1: Gluma desensitizer, Group 2: Vivasens desensitizer, Group 3: Gluma Comfort Bond and desensitizer, and Group 4: Adper Single Bond 2. Composite resin post of 2 mm in height and width were built on these specimens. The samples were then mounted in acrylic resin blocks. Universal testing machine was used to test the shear bond strength. The data were analyzed using one-way analysis of variance (ANOVA) and post hoc Tukey's test. Results The mean values of the shear bond strength were for: Group 1—18.61 ± 1.03 MPa, Group 2—17.53 ± 1.36 MPa, Group 3—22.63 ± 1.61 MPa and Group 4—23.12 ± 1.02 MPa. There was a statistically significant difference (p < 0.05) among the groups. Conclusion The use of dentin desensitizers’ influences bond strength between the tooth and the adhesive. Among the various agents, the single bottle system containing Gluma comfort bond and desensitizer had the best adhesion among the desensitizer groups. How to cite this article Patil S, Naik B, Shetty P. A Comparative Evaluation of Three Commercially Available Dentin Desensitizers on the Shear Bond Strength of Composite Resins: An in vitro Study. J Contemp Dent 2015;5(2):65-68.

Investigation of the retention forces of secondary telescopic crowns made from Pekkton® ivory in combination with primary crowns made from four different dental alloys: an in vitro study

2019 ◽  
Vol 64 (5) ◽  
pp. 555-562 ◽  
Author(s):  
Marie Kotthaus ◽  
Istabrak Hasan ◽  
Ludger Keilig ◽  
Manfred Grüner ◽  
Christoph Bourauel ◽  
...  
Keyword(s):  
Precious Metal ◽  
In Vitro Study ◽  
Dental Alloys ◽  
Retention Force ◽  
Group 4 ◽  
Force Transducers ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

Abstract The aim of this study was to investigate the retention forces of secondary telescopic crowns made of polyetherketoneketone (PEKK) in combination with primary crowns made of four different dental alloys and to determine whether the retention forces change in the course of up to 5000 simulated wear cycles. A total of four groups of telescopic crowns were investigated: group 1: 10 primary crowns made of a gold alloy (NEOCAST®3), group 2: 10 primary crowns made of a non-precious metal alloy (Girobond NB), group 3: 10 primary crowns made of zirconium (Cercon®base) and group 4: 10 primary crowns made from PEKK (Pekkton®ivory). The corresponding secondary crowns were made from PEKK in all the four groups. Each pair was fixed axially in a wear simulator specifically designed for the study. Overall, 10,000 joining and separating cycles were performed for each group. To simulate intraoral conditions, a saliva substitute served as a lubricant. Force transducers were used to record the retention forces and after completing 10,000 cycles, the surface of each primary crown was examined using a scanning electron microscope (SEM). All groups showed an increase in the retention force for the first 2000 cycles which stayed constant for the remaining 8000 cycles. The Pekkton®ivory/Pekkton®ivory and NEOCAST®3/Pekkton®ivory combinations displayed mean retention force values of 16 N after a slight increase in the retention force. The Cercon®base/Pekkton®ivory and Girobond NB/Pekkton®ivory combinations displayed an initially high increase in the retention force and then showed a mean retention force of up to 29 N. All primary crowns displayed surface wear. Zirconium primary crowns showed the least wear compared to PEKK and the gold and non-precious metal alloys.

Microleakage of a resin sealan using diferents adhesive systems

2018 ◽  
Vol 14 (2) ◽  
Author(s):  
K Licla
Keyword(s):  
Orthophosphoric Acid ◽  
In Vitro Study ◽  
Adhesive Systems ◽  
Group 4 ◽  
Fifth Generation ◽  
Group 3 ◽  
Group 2 ◽  
Sealant Group ◽  
Group 1

Objetive: To compare the microleakage of a resinsealant using fifth generation adhesive systems,seventh generation with or without preconditioningof orthophosphoric acid at 37%. Materials and Methods: An in vitro study wasmade on 60 human premolars, randomized into4 groups of 15 elements each. Group 1 (control):phosphoric acid at 37%, sealant; Group 2: orthophosphoricacid, adhesive of fifth generation, sealant; Group 3: adhesive of seventh generation,sealant; Group 4: orthophosphoric acid, adhesiveof seventh generation, sealant. They were puton a thermocycler, 500 cycles (5° y 55°C) per 30seconds on higher and lower temperatures, afterthat the specimens were drawn for 24 hours on1% methylene blue, cut off on a bucco-lingualway and evaluated on a stereomicroscope on 16x.Chi square test was used with a 0.05 significancelevel. Results: The greater percentage of microleakageshowed: control-adhesive without (53.3%), fifthgeneration (20%), the seventh generation (80%)and conditioning with orthophosphoric acid andadhesive seventh generation (67.7%). Conclusion: Microfiltration grade adhesivesealant fifth generation was lower than using theother adhesives.

scholarly journals Fracture Resistance of Composite Veneers with Different Preparation Designs

2016 ◽  
Vol 20 (2) ◽  
pp. 99-103
Author(s):  
Katerina Zlatanovska ◽  
Ljuben Guguvcevski ◽  
Risto Popovski ◽  
Cena Dimova ◽  
Ana Minovska ◽  
...  
Keyword(s):  
Fracture Resistance ◽  
In Vitro Study ◽  
Fracture Load ◽  
Group 3 ◽  
The Mean ◽  
Group 2 ◽  
Preparation Design ◽  
Frequent Localization ◽  
Group 1

Summary Background: The aim of this in vitro study was to examine the fracture load of composite veneers using three different preparation designs. Material and methods: Fifteen extracted, intact, human maxillary central incisors were selected. Teeth were divided into three groups with different preparation design: 1) feather preparation, 2) bevel preparation, and 3) incisal overlap- palatal chamfer. Teeth were restored with composite veneers, and the specimens were loaded to failure. The localization of the fracture was recorded as incisal, gingival or combined. Results: Composite veneers with incisal overlap - palatal chamfer showed higher fracture resistance compared to feather preparation and bevel preparation. The mean (SD) fracture loads were: Group 1: 100.6±8.0 N, Group 2: 107.4±6.8 N, and Group 3: 122.0±8.8 N. The most common mode of failure was debonding for veneers with feather preparation and fracture when incisal edge is reduced. The most frequent localization of fracture was incisal. Conclusion: The type of preparation has a significant effect on fracture load for composite veneers. This study indicates that using an incisal overlap- palatal chamfer preparation design significantly increases the fracture resistance compared to feather and bevel preparation designs.

scholarly journals Comparative Evaluation of Self-etching Primers and Phosphoric Acid Effectiveness on Composite to Enamel Bond: An in vitro Study

2013 ◽  
Vol 14 (5) ◽  
pp. 790-795 ◽  
Author(s):  
G Vinay Kumar ◽  
Basanagouda S Patil ◽  
BK Raghavendra Rao ◽  
SM Sharathchandra ◽  
Reshma Hegde
Keyword(s):  
Phosphoric Acid ◽  
Bond Strength ◽  
Comparative Evaluation ◽  
In Vitro Study ◽  
Vitro Study ◽  
One Step ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

ABSTRACT Aim The aim of the present study was to investigate the effectiveness of the one total-etch self-priming adhesive, one two-step self-etching primer adhesive, and one ‘all-in-one’ selfetching adhesive system on the adhesion of a resin composite to enamel. Materials and methods Thirty-six freshly extracted human mandibular molars were selected for this study. A flat area about 5 mm in diameter was created on the exposed mesial surface of enamel of each tooth by moist grinding with 320, 420 and 600 grit silicon carbide paper. Twelve teeth were randomly assigned into three groups. In group 1, Adper Easy One (3M ESPE), a one step self-etching primer adhesive was applied and light curing unit for 10 seconds. In group 2, Adper SE Plus, a twostep self-etching primer with bottle A containing the aqueous primer and bottle B containing the acidic adhesive was applied and light cured for 10 seconds. Group 3 (control)—etchant 37% phosphoric acid is applied to the surface for 15 seconds and rinsed with water and air dried and adhesive (single bond 2) is applied to the surface and tube is placed and light cured for 20 seconds. Composite material (Z350) was placed in the tube and light cured for 40 seconds in all the groups. Bond strength testing was done using universal testing machine at the enamel-composite interface. The debonded enamel surface was evaluated in stereomicroscope to assess the cohesive, adhesive or mixed fracture. Data was statistically analyzed by one way analysis of variance (ANOVA). Results Group 1 performed least among all groups with a mean score of 19.46 MPa. Group 2 had a mean score of 25.67 MPa. Group 3 had a mean score of 27.16 MPa. Conclusion Under the conditions of this in vitro study, the bond strength values of the two-step self-etching primer systems tested were similar to the total-etch. And, one step self-etching primers have lower bond strength compared to the total-etch. How to cite this article Patil BS, Rao BKR, Sharathchandra SM, Hegde R, Kumar GV. Comparative Evaluation of Selfetching Primers and Phosphoric Acid Effectiveness on Composite to Enamel Bond: An in vitro Study. J Contemp Dent Pract 2013;14(5):790-795.

scholarly journals Effect of Different Sintering Cycles on the Surface Hardness of Full Contour Monolithic Zirconia – An In Vitro Comparative Study

2021 ◽  
Vol 10 (28) ◽  
pp. 2089-2093
Author(s):  
Sanath Kumar Shetty ◽  
Feba Maria Varghese ◽  
Mohammed Zahid ◽  
Savitha Dandekeri ◽  
Fowzaan Feroz
Keyword(s):  
Surface Hardness ◽  
In Vitro Study ◽  
Group 4 ◽  
Cad Cam ◽  
Monolithic Zirconia ◽  
Group 3 ◽  
Group 2 ◽  
Cycle Group ◽  
Group 1

BACKGROUND This in-vitro study was conducted to compare the effect of different sintering cycles on the surface hardness of full contour monolithic Zirconia. METHODS In this in-vitro study, a total of 28 bar shaped Zirconia samples of final dimensions 20 x 4 x 2 mm were fabricated using Amann Girrbach CAD - CAM unit. These samples were randomly allocated into four groups with 7 samples in each group namely, Group 1, 2, 3 and 4 (Group 1: Long sintering cycle, Group 2: Intermediate sintering cycle, Group 3: Short sintering cycle, Group 4: Ultra-short sintering cycle) and sintered under the respective sintering cycles. The Ceramill® Therm sintering furnace provided 3 sintering cycles ranging from the longest Group - 1 (19 hours), to the short sintering cycle Group - 3 (8 hours), with an intermediate sintering cycle Group - 2 (15hours). The Zircom sintering furnace provided an ultra-short sintering cycle Group - 4 (2 hours). The testing of surface hardness was performed using TECSOL hardness tester. Statistical analysis of the collected data was performed by one - way ANOVA using SPSS software. Multiple comparison was done using post-hoc Tukey’s test. RESULTS One - way ANOVA showed statistically significant difference in the surface hardness of different samples (P < 0.05). The highest mean hardness was observed in Group 3 with 2713.757 + 233.89 VHN, followed by Group 2 with 2595.714 + 62.35 VHN, followed by Group 4 with 2518.600 + 103.65 VHN and Group 1 with the least, 1734.300 + 460.20 VHN. CONCLUSIONS The surface hardness of full contour monolithic Zirconia was influenced to some extent by various sintering cycles. The longest sintering cycle showed the least surface hardness whereas, the short sintering cycle showed the highest surface hardness. Also the ultra-short sintering cycle of 2 hours exhibited surface hardness comparable to the other sintering cycles with longer duration, making it a viable alternative to the conventional sintering cycles. KEY WORDS Monolithic Zirconia, CAD - CAM, Sintering, Hardness

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