scholarly journals The effect of frog pressure and downward vertical load on hoof wall weight-bearing and third phalanx displacement in the horse - an in vitro study : research communication

2001 ◽  
Vol 72 (4) ◽  
Author(s):  
A. Olivier ◽  
J. Wannenburg ◽  
R.D. Gottschalk ◽  
M.J. Van der Linde ◽  
H.T. Groeneveld
Keyword(s):  
Solar Surface ◽  
Weight Bearing ◽  
Testing Machine ◽  
Vertical Component ◽  
In Vitro Study ◽  
Vitro Study ◽  
Total Weight ◽  
Strain Gauges ◽  
Tensile Testing Machine

A shoe was designed to combine the advantages of a reverse shoe and an adjustable heart bar shoe in the treatment of chronic laminitis. This reverse even frog pressure (REFP) shoe applies pressure uniformly over a large area of the frog solar surface. Pressure is applied vertically upward parallel to the solar surface of the frog and can be increased or decreased as required. Five clinically healthy horses were humanely euthanased and their dismem-bered forelimbs used in an in vitro study. Frog pressure was measured by strain gauges applied to the ground surface of the carrying tab portion of the shoe. A linear variable distance transducer (LVDT) was inserted into a hole drilled in the dorsal hoof wall. The LVDT measured movement of the third phalanx (P3) in a dorsopalmar plane relative to the dorsal hoof wall. The vertical component of hoof wall compression was measured by means of unidirectional strain gauges attached to the toe, quarter and heel of the medial hoof wall of each specimen. The entire limb was mounted vertically in a tensile testing machine and submitted to vertical downward compressive forces of 0 to 2500 Nat a rate of 5 cm/minute. The effects of increasing frog pressure on hoof wall weight-bearing and third phalanx movement within the hoof were determined. Each specimen was tested with the shoe under the following conditions: zero frog pressure; frog pressure used to treat clinical cases of chronic laminitis (7 N-cm); frog pressure clinically painful to the horse as determined prior to euthanasia; frog pressure just alleviating this pain. The specimens were also tested after shoe removal. Total weight-bearing on the hoof wall at zero frog pressure was used as the basis for comparison. Pain-causing and pain-alleviating frog pressures decreased total weight-bearing on the hoof wall (P < 0.05). Frog pressure of 7 N-cm had no statistically significant effect on hoof wall weight-bearing although there was a trend for it to decrease as load increased. Before loading, the pain-causing and pain-alleviating frog pressures resulted in a palmar movement of P3 relative to the dorsal hoof wall compared to the position of P3 at zero frog pressure (P < 0.05). This difference remained statistically significant up to 1300 Nload. At higher loads, the position of P3 did not differ significantly for the different frog pressures applied. It is concluded that increased frog pressure using the REFP shoe decreases total hoof wall weight-bearing and causes palmar movement of P3 at low weight-bearing loads. Without a shoe the toe and quarter hoof wall compression remained more constant and less in magnitude, than with a shoe.

scholarly journals Efficacy of Fiber Post Bonding To Root Dentin after Different Obturation Techniques and Cementation Timings: In Vitro Study

2018 ◽  
Vol 6 (9) ◽  
pp. 1707-1711
Author(s):  
Rami M. Atia ◽  
Nada Omar ◽  
Haidy Nabil ◽  
Yousra Aly
Keyword(s):  
Bond Strength ◽  
Statistical Significance ◽  
Testing Machine ◽  
In Vitro Study ◽  
Resin Cement ◽  
Vitro Study ◽  
Endodontically Treated Teeth ◽  
Root Dentin ◽  
Push Out

OBJECTIVE: The aim of this in vitro study was to assess the effect of obturation technique and cementation timings on the bonding of fibre-reinforced posts to the root canal walls. METHODS: Twenty extracted teeth were randomly allocated to two groups according to the obturation technique and cementation timing. Central incisors with single canals were used after being decoronated. Every extracted tooth of the {vertical compaction group} (VC) group (n = 10) had been obturated using the {E & Q plus obturation system} with posts cemented in the same day; The other (CO) conventional group (n = 10) teeth were obturated using the conventional lateral compaction technique and posts cemented after one week. “SF“ Fiber posts were used after bonding and cementation using Rely X ARC resin cement with all the endodontically treated teeth. The push-out test was performed in a universal testing machine. Data were analysed by 2 way analysis of variance with Statistical significance was set to 0.05. RESULTS: Heat softened gutta percha group showed more push out the bond strength of the bonded posts than the conventional obturation group (p < 0.05). In the middle region, there was no statistical significance between the two groups while there was significance in the coronal and apical thirds. CONCLUSION: The vertical compaction technique and early cementation improved the bond strength of the resin posts in comparison to the conventional obturation technique with late cementation.

Tensile bond strength of intracanal posts in primary anterior teeth: an in vitro study

2003 ◽  
Vol 27 (1) ◽  
pp. 35-39 ◽  
Author(s):  
Silvia Pithan ◽  
Ricardo de Sousa Vieira ◽  
Marcelo Carvalho Chain
Keyword(s):  
Bond Strength ◽  
Composite Resin ◽  
Testing Machine ◽  
Glass Ionomer Cement ◽  
In Vitro Study ◽  
Vitro Study ◽  
Tensile Bond Strength ◽  
Anterior Teeth ◽  
Group I

The aim of this study was to measure in vitro; the tensile bond strength of three intracanal posts used in anterior primary teeth. A total of 45 single rooted primary anterior teeth were selected for the study and the crowns sectioned leaving 1mm above the cement-enamel junction. The roots were then assigned to three groups according the type of retention used. All roots were endodonticaly treated, a 4-mm of the canal was cleansed and a base of glass ionomer cement was put at the bottom of the prepared canal. The roots were then prepared to receive intracanal posts using a # 4137 diamond bur (KG Sorensen) used in a depth of 3-mm of the length of the canal. All the prepared roots were acid etched with a 37% phosphoric acid gel for 15 seconds, rinsed, dried and the dentin adhesive Single Bond (3M) was applied. Group I received intracanal posts and cores made of composite resin (Filtek Z 250, 3M). Group II intracanal posts were made from a 0.6mm orthodontic wire bent as a Greek letter type (gamma), fixed with the Z 250 composite resin and cores were built with the same composite. Finally Group III received intracanal retention made of a fiber glass post (Fibrekor Post, Generic/Pentron) with 1.25mm diameter, fixed with Z 250 and cores were made like the other groups. The samples were submitted to tension in a universal- testing machine (Instron, model 4444). Statistical analysis (ANOVA) reveled that there were no statistically significant differences between the groups. On the basis of the results of this in vitro study it was concluded that the type of intracanal post did not interfere with the tensile strength and the most frequent type of failure was of adhesive type, corresponding to 74% of the sample.

scholarly journals Effects of a newly designed apparatus on orthodontic skeletal anchorage

2013 ◽  
Vol 07 (S 01) ◽  
pp. S083-S088 ◽  
Author(s):  
Murat Tozlu ◽  
Didem Nalbantgil ◽  
Fulya Ozdemir
Keyword(s):  
Cortical Bone ◽  
Lateral Displacement ◽  
Tangential Force ◽  
Testing Machine ◽  
In Vitro Study ◽  
Vitro Study ◽  
Favorable Effect ◽  
Control Group ◽  
Insertion Torque

ABSTRACT Objective: An appliance was designed to increase the cortical bone surface contact area of miniscrew implants (MSIs). The purpose of this in vitro study was to evaluate the effects of this appliance on the anchorage force resistance and the stability of orthodontic MSIs. Materials and Methods: A total of 48 MSIs were placed into bone specimens prepared from the ilium of bovines. Half were placed with the newly designed apparatus and half were placed conventionally. All the specimens were subjected to tangential force loading perpendicular to the MSI with lateral displacement of 0.6 mm, using an Instron Universal Testing machine. The maximum removal torque of each tested specimen was also recorded. Both study and control groups were divided into two subgroups based on whether they had thin and thick cortical bone. Results: The test group had statistically higher force anchorage resistance and maximum insertion torque values than the control group (p < 0.001). The results were found to be more significant in cases in which the cortical bone was thin (p < 0.001). Conclusions: Within the limits of this in vitro study, the present findings suggest that the newly designed apparatus might have a favorable effect on MSI stability in patients presenting with thin cortical bone. Clinical studies are necessary to confirm the results that were observed in vitro.

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.

scholarly journals Effect of acidic environment and intracanal medicament on push-out bond strength of biodentine and mineral trioxide aggregate plus: an in vitro study

2019 ◽  
Author(s):  
Priyanka Jain ◽  
Zinnie Nanda ◽  
Rahul Deore ◽  
Amit Gandhi
Keyword(s):  
Bond Strength ◽  
Calcium Hydroxide ◽  
Testing Machine ◽  
Mineral Trioxide Aggregate ◽  
In Vitro Study ◽  
Vitro Study ◽  
Acidic Environment ◽  
Significant Difference ◽  
Push Out

Introduction. This in-vitro study aims to evaluate the effect of acidic environment and intracanal medicament on push out bond strength of Biodentine and Mineral Trioxide Aggregate Plus (MTA Plus) Method. Forty extracted single rooted teeth were sectioned below the cement-enamel junction. The root canals were instrumented using rotary files and then peeso reamer was used to obtain standardized root canal dimension. Specimens were randomly classified into following groups- Group 1: calcium hydroxide in the absence of acidic environment; Group 2: calcium hydroxide in the presence of acidic environment; Group 3: no intracanal medicament in the absence of acidic environment; Group 4: no intracanal medicament in the presence of acidic environment. Specimens were kept for 7 days at room temperature. Thereafter, specimens of each group were transversely sectioned into 1 mm thick slices and divided into 2 sub-groups according to the use of biodentine and MTA Plus. Using Universal Testing Machine, push out bond strength test was carried out and the data were analyzed statistically. Results. There was no statistically significant difference  in the bond strength of biodentine and MTA Plus (P>0.05). For both MTA Plus and biodentine, with or without calcium hydroxide, the push out bond strength was less in acidic environment and this difference was more pronounced without calcium hydroxide. In all the four groups, MTA plus showed comparable bond strength to biodentine. Conclusion. MTA Plus is a viable option for apexification. The push out bond strength of Biodentine and MTA Plus is impaired by acidic environment. Prior application of calcium hydroxide slightly increased the bond strength, though the difference was statistically  insignificant.    

Comparison of Fracture Strengths among different Commonly Placed Anterior Esthetic Restorations for Primary Dentition: An in vitro study

2021 ◽  
Vol 45 (3) ◽  
pp. 171-176
Author(s):  
Brent Lin ◽  
Amit Khatri ◽  
Michael Hong
Keyword(s):  
Fracture Strength ◽  
Testing Machine ◽  
In Vitro Study ◽  
Vitro Study ◽  
Anterior Teeth ◽  
Study Results ◽  
Luting Cement ◽  
Significant Difference ◽  
All Ceramic

The purpose of this study was to determine and compare the shear force (N) required to fracture or dislodge an all-ceramic zirconia-based crown using different luting cement with those of polycarbonate crown and strip crown for the primary anterior teeth in vitro. Study design: Four groups of esthetic restoration for primary anterior teeth were tested for fracture strength: 1) Fifteen all-ceramic zirconia-based crowns cemented with glass ionomer cement, 2) Fifteen all-ceramic zirconia-based crowns bonded with a self-adhesive resin cement, 3) Fifteen polycarbonate crowns cemented with a polymer reinforced zinc-oxide eugenol and 4) Fifteen resin strip crowns. All restorations were placed and cemented on reproductions of dies in an independent laboratory at Delhi, India. All samples underwent loading until fracture or dislodgement with the Universal Testing Machine. The force in Newton (N) required to produce failure was recorded for each sample and the type of failures was also noted and characterized. One-way analysis of variance (ANOVA) test and the Tukey and Scheffe’s post hoc comparisons were used for statistical analyses. Results: In this invitro study, results were measured in Newtons (N). Group 1 (410.9±79.5 N) and Group 2 (420.5±57.8 N) had higher fracture strength than Group 3 (330.3±85.6 N) and Group 4 (268.4±28.2 N). These differences were statistically significant at P≤.05 among the sample groups. No significant difference was found between groups 1 and 2 (P = 0.984) nor between groups 3 and 4 (P =0.104). Among type of failures, majority of restoration fractures for zirconia-based crowns and resin strip crowns were due to cohesive failures and polycarbonate crowns had predominantly mixed failures. Conclusions: Under the limitations of this in vitro study, it could be concluded that all-ceramic zirconia-based crowns attained the highest fracture strength among all restorative samples tested regardless of the type of luting agent employed (P&lt;.01). Cohesive failures were commonly observed in the zirconia crowns and resin strip crowns, whereas polycarbonate crowns revealed predominately mixed failures.

scholarly journals Assessment of the Different Types of Failure on Anterior Cantilever Resin-Bonded Fixed Dental Prostheses Fabricated with Three Different Materials: An In Vitro Study

2020 ◽  
Vol 10 (12) ◽  
pp. 4151
Author(s):  
Adolfo Di Fiore ◽  
Edoardo Stellini ◽  
Gianpaolo Savio ◽  
Stefano Rosso ◽  
Lorenzo Graiff ◽  
...  
Keyword(s):  
Fracture Strength ◽  
Testing Machine ◽  
In Vitro Study ◽  
Load Resistance ◽  
Vitro Study ◽  
Stl File ◽  
Fixed Dental Prosthesis ◽  
Different Types ◽  
Ceramic Fillers

background: resin-bonded fixed dental prosthesis (RBFDP) represents a highly aesthetic and conservative treatment option to replace a single tooth in a younger patient. The purpose of this in vitro study was to compare the fracture strength and the different types of failure on anterior cantilever RBFDPs fabricated using zirconia (ZR), lithium disilicate (LD), and PMMA-based material with ceramic fillers (PM) by the same standard tessellation language (STL) file. Methods: sixty extracted bovine mandibular incisives were embedded resin block; scanned to design one master model of RBFDP with a cantilevered single-retainer. Twenty cantilevered single-retainer RBFDPs were fabricated using ZR; LD; and PM. Static loading was performed using a universal testing machine. Results: the mean fracture strength for the RBFDPs was: 292.5 Newton (Standard Deviation (SD) 36.6) for ZR; 210 N (SD 37.6) for LD; and 133 N (SD 16.3) for PM. All the failures of RBFDPs in ZR were a fracture of the abutment tooth; instead; the 80% of failures of RBFDPs in LD and PM were a fracture of the connector. Conclusion: within the limitations of this in vitro study, we can conclude that the zirconia RBFDPs presented load resistance higher than the maximum anterior bite force reported in literature (270 N) and failure type analysis showed some trends among the groups

scholarly journals The Effect of Chlorhexidine and Listerine® Mouthwashes on the Tensile Strength of Selected Absorbable Sutures: An In Vitro Study

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Mohammed Alsarhan ◽  
Hourya Alnofaie ◽  
Rawan Ateeq ◽  
Ahmed Almahdy
Keyword(s):  
Tensile Strength ◽  
Artificial Saliva ◽  
Critical Role ◽  
Testing Machine ◽  
In Vitro Study ◽  
Vitro Study ◽  
Suture Materials ◽  
Experimental Conditions ◽  
Absorbable Sutures

Background. Suturing plays a critical role in the healing of surgical wounds. The tensile strength of suture materials indicates the ability of the material to withstand stress during knotting and protect the wound during an extended period of healing. Objective. An in vitro study was conducted to determine the effect of two commercially available mouthwashes on the tensile strength and breakage mode of two absorbable intraoral sutures. Materials and Methods. Two common absorbable sutures, Vicryl® and Monocryl®, both with 4-0 and 5-0 gauges were used. A total of 400 specimens were sutured around rubber rods and immersed in three thermostatically controlled experimental conditions: artificial saliva, 0.2% chlorhexidine gluconate (Parodontax® extra), and essential oils-based rinse (Listerine® Zero™), and these were compared to a nonimmersed dry condition. All specimens were stored in an incubator at 37°C. Tensile strengths were assessed after days 1, 3, 7, 10, and 14 of immersion using a universal Instron® testing machine. The maximum load for suture breakage and the location of the point of breakage were assessed. Results. Unlike Monocryl® 4-0, the tensile strength of both gauges of Vicryl® sutures significantly increased in chlorhexidine and Listerine®. There was a significant decrease in the strength for all suture types after day 10, regardless of the immersion solution. Listerine® significantly reduced the tensile strength of Monocryl® 5-0. Conclusion. Oral surgeons and periodontists should be cautious when prescribing commercial mouthwashes for patients relative to their selection of suture materials. However, further studies are needed to understand the molecular changes in sutures when exposed to chemical solutions found in mouthwashes.

scholarly journals Efficacy of Super Slick Elastomeric Modules in reducing Friction during Sliding: A Comparative in vitro Study

2014 ◽  
Vol 15 (5) ◽  
pp. 543-551 ◽  
Author(s):  
Sadhiq Khan Pattan ◽  
Revathi Peddu ◽  
Shyam Kumar Bandaru ◽  
Devikanth Lanka ◽  
Kalyani Mallavarapu ◽  
...  
Keyword(s):  
Testing Machine ◽  
Calculated Data ◽  
In Vitro Study ◽  
Frictional Resistance ◽  
Human Saliva ◽  
Vitro Study ◽  
Kinetic Friction ◽  
Wet Condition ◽  
Frictional Forces

ABSTRACT Aim To evaluate and compare the frictional resistance produced by Super Slick modules during sliding with four different types of brackets and four ligature types both in conventional and figure-of-8 ligation method with saliva as lubricant. Materials and methods The frictional resistance was evaluated by using four different ligatures on 0.019” × 0.025” stainless steel (SS) archwires using four different brackets using an universal testing machine with unstimulated saliva as a lubricant. Mean and SD values were calculated. Data was statistically analyzed using analysis of variance ANOVA with post hoc test. Results The results showed that self-ligating brackets produced least frictional forces. Among all other tested combinations, Teflon-coated SS ligatures in ceramic with metal slot brackets produced least coefficient of static and kinetic friction and full ceramic brackets ligated with Super Slick elastomeric modules demonstrated the highest, with other combinations falling in between. Conclusion Super Slick elastomeric modules, produced highest coefficient of both static and kinetic friction with the conventional and figure-of-8 ligation technique even in wet conditions using natural fresh human saliva. Clinical significance Both static and kinetic frictional resistance play an important role during sliding mechanics. Various factors have been attributed for friction. However, bracket type, archwire material, type of ligature and method of ligation are important variables. Recently polymeric coated slick elastomeric modules were introduced with the claim that they produce very low frictional forces in wet condition. Contrary to the claim made by the manufacturers of Super Slick elastomeric modules, they produced highest coefficient of both static and kinetic friction with the conventional and figure-of-8 ligation technique. How to cite this article Pattan SK, Peddu R, Bandaru SK, Lanka D, Mallavarapu K, Pathan AB. Efficacy of Super Slick Elastomeric Modules in reducing Friction during Sliding: A Comparative in vitro Study. J Contemp Dent Pract. 2014; 15(5):543-551.

scholarly journals Assessing Fracture Resistance of Restored Premolars with Novel Composite Materials: An In Vitro Study

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Zahraa Abdulaali Al-Ibraheemi ◽  
Huda Abbas Abdullah ◽  
Nada Abdlameer Jawad ◽  
Julfikar Haider
Keyword(s):  
Fracture Resistance ◽  
Testing Machine ◽  
In Vitro Study ◽  
Vitro Study ◽  
Resistance Testing ◽  
Significant Difference ◽  
Group A ◽  
Group B ◽  
Group D

During restorative treatment, premolars restored with resin filling materials using the conventional incremental-fill technique take longer restoration time and undermine the integrity of the tooth. The aim of this study was to assess fracture resistance of premolars restored by various types of novel bulk-fill composite resin materials. Forty-eight (n = 48) freshly extracted sound maxillary first premolars were used in this in vitro study. The teeth were divided into six groups, each having 8 specimens. Group A (positive control) was allocated for the intact teeth. For specimens in Groups B to F, a large cavity (Class-II MOD) was prepared with a standardized dimension of cavity (3 mm depth on the pulpal floor, 4 mm at the gingival seat, and 3 mm cavity width). Group B represented prepared teeth without any restoration. Group C, Group D, Group E, and Group F were restored with Tetric EvoCeram® incremental-fill (conventional), Beautifil bulk-fill, Filtek posterior bulk-fill, and SonicFill 2 bulk-fill restorative materials, respectively. All samples were finished and polished with an enhanced finishing kit and stored in distilled water for a month before the fracture resistance testing. All the samples were exposed to the axial loading (the speed of crosshead was 1 mm/min) in a computer-controlled universal testing machine (LARYEE, China) via a steel bar (6 mm in diameter) and the maximum applied force in Newton was recorded as the fracture resistance. One-way analysis of variance (SPSS 21) was used to compare the fracture resistance within the groups, and Tukey’s post hoc test was used to determine the difference between the groups. The lowest value of fracture resistance was recorded for Group B, and the highest value was recorded for Group A followed by the values of Group D, Group C, Group F, and Group E. One-way ANOVA revealed a statistically significant difference between the groups ( P < 0.05 ). Nonsignificant difference was found between the premolars restored by bulk-fill and conventional composites. Among the bulk-fill restored specimens, Beautifil restorative demonstrated significantly higher fracture resistance in comparison with the other two bulk-fill restored specimen groups (SonicFill 2 and Filtek). Bulk-fill composite such as Beautifil could be an alternative option to conventional incremental-fill composite for premolar restoration.

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