The comparative biomechanics of the reinforced interdental crossover and the Stout loop composite splints for mandibular fracture repair in dogs

Summary Objectives: To describe a new technique, the reinforced interdental crossover composite splint (RIC), for transverse mandibular fracture repair in dogs. This technique was compared biomechanically with the established reinforced interdental Stout loop composite splint (RIS) technique. Methods: Six pairs of mandibles from young adult small breed dogs were used for the study. Osteotomies were created in a standardized fashion and fixed with either RIC or RIS. All composite splint constructs were tested biomechanically with a cantilever bending force, using a single column testing machine at a rate of 2 mm/min. The time of application, amount of composite used, ultimate force, stiffness, total displacement, and total energy absorbed during displacement of the rostral mandibular segment were calculated and compared between the two groups. Results: No significant difference was found when comparing the time of application of the RIC and the RIS techniques. All implants failed by either composite resin fracture over the region of the osteotomy or by fracture between the first and second molar followed by detachment of the resin from the lingual enamel surface of the first molar. Differences between the RIC and RIS in force (80.5 N ± 40.3 and 51.8 N ± 27.4. respectively) and stiffness (16.2 N/mm ± 4.4 and 10.1 N/mm ± 4.1 respectively) were significant (p = 0.03). However differences between the two techniques in displacement and total energy absorbed were not significant. Clinical significance: In experimentally fractured mandibles of young adult dogs there is evidence that RIC is biomechanically similar to RIS.

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The Effect of Interincisal Opening, Cavity Location and Operator Experience on the Energy Delivered by a Light-Curing Unit to a Simulated Dental Restoration

Primary Dental Journal ◽

10.1308/205016814812144030 ◽

2014 ◽

Vol 3 (2) ◽

pp. 26-31 ◽

Cited By ~ 2

Author(s):

Nor Asilah Harun ◽

Ario Santini ◽

Elizabeth M Roebuck

Keyword(s):

Total Energy ◽

Mouth Opening ◽

Nonparametric Test ◽

Dental Restoration ◽

Clinical Environment ◽

Patient Simulator ◽

Operator Experience ◽

Second Molar ◽

Significant Difference ◽

Light Curing

Background Curing of resin-based composites depends on the delivery of adequate total energy, which may be operator dependent. Aim To determine the effect of interincisal opening, cavity location and operator experience on the total energy delivered to simulated cavity preparation sites. Design Three cohorts were included: junior dental nurses, senior dental nurses and qualified dentists (N=5, each cohort). Each operator (participant) followed the same procedure and light-cured two simulated restorations in a MARC® patient simulator using a Demi™ light-curing unit for 20 seconds in each of the following situations: left upper second molar (UL7), interincisal opening at both 25mm and 45mm; upper central incisor (UR1), interincisal opening at 45mm. The light energy delivered by each operator in each situation was recorded. Five readings for each operator were taken at each interincisal distance. Statistical comparisons of delivered energy (J/cm2) between interincisal openings, location and groups in the total energy delivered were performed using the Kruskal-Wallis nonparametric test: α=0.05. Results Less total energy was delivered to the posterior cavity at 25mm (12.0 ± 5.3J/cm2) than at 45mm (16.9 ± 5.6J/cm2) by all operators ( P<0.05). At 45mm, less total energy was delivered to the posterior cavity compared to the anterior cavity (25.1 ± 7.4J/cm2; P<0.05). There was no statistically significant difference between junior nurses and qualified dentists ( P>0.05) but there was a significant difference in the total energy delivered between senior nurses (20.1 ± 7.8J/cm2) and junior nurses (17.5 ± 7.6J/cm2) and between senior nurses and qualified dentists (16.6 ± 8.7J/cm2) ( P<0.05). Conclusions Interincisal mouth opening, location of the cavity and operator experience affected the total energy delivered to cavities in a simulated clinical environment.

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Influence of Cusp Inclination and Type of Retention on Fracture Load of Implant-Supported Crowns

Brazilian Dental Journal ◽

10.1590/0103-6440201701342 ◽

2017 ◽

Vol 28 (1) ◽

pp. 92-96

Author(s):

Cibele Oliveira de Melo Rocha ◽

Diogo Longhini ◽

Rodrigo de Paula Pereira ◽

João Neudenir Arioli Filho

Keyword(s):

Testing Machine ◽

Fracture Load ◽

Second Molar ◽

Significant Difference ◽

Metal Ceramic ◽

Mandibular Second Molar ◽

Ceramic Crowns ◽

Post Hoc ◽

Single Crowns ◽

Supported Metal

Abstract There are few informations about the influence of cusp inclination on the fracture strength of implant-supported crowns. The study aimed to evaluate the influence of cusp inclination and retention type on fracture load in implant-supported metal-ceramic single crowns. Sixty crowns were made, classified as cemented and screw-retained with screw access hole (SAH) sealed or not. Standard (33°) and reduced (20°) cusp inclinations were tested for each group (n=10). To support crowns of a mandibular second molar, analogs of external hexagon implants 5.0 were used. The fracture load was measured in a universal testing machine EMIC DL2000 (10 kN load cell; 0.5 mm/min). Two-way ANOVA (retention and cusp inclination) followed by post hoc Tukey’s honest significant difference test was used for the statistical analyses (a=0.05). Crowns with reduced cusp inclination exhibited significantly higher fracture load (p<0.01) than crowns with standard cusp inclination. Cemented crowns showed significantly higher fracture load (p<0.01) than screw-retained crowns. The interaction among these factors was not significant (p>0.05) for the fracture load. The sealing of SAH did not influence the fracture load of screw-retained crowns (p>0.05). In conclusion, fracture load of implant-supported metal-ceramic crowns was influenced by retention and cusp inclination, and there was no influence of the sealing of SAH.

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Investigation of Bioabsorbable Screw Usage for Longbone Fracture Repair in the Horse: Biomechanical Features

Veterinary and Comparative Orthopaedics and Traumatology ◽

10.1055/s-0038-1633145 ◽

1993 ◽

Vol 06 (01) ◽

pp. 42-46 ◽

Cited By ~ 1

Author(s):

T. C. Hearn ◽

M. Arighi ◽

J. R. Field

Keyword(s):

Tensile Force ◽

Testing Machine ◽

Fracture Repair ◽

Materials Testing ◽

Bone Material ◽

Bioabsorbable Screw ◽

Axial Tensile ◽

Metacarpal Bones ◽

Significant Difference ◽

Biomechanical Features

SummaryThe purpose of the study was to compare the biomechanical features of bioabsorbable, self-reinforced polyL-lactic acid (SR-PLLA) and stainless steel 4.5 mm ASIF screws. Paired extraction tests were conducted in matched third metacarpal bones and in a synthetic bone material composed of polyurethane foam. The tests were accomplished using a servohydraulic materials testing machine. From these tests the maximum value of tensile force, achieved during extraction, was recorded as the screw “holding strength‘.Comparison of holding strengths in horse cadaver bones revealed a significant difference (p = 0.0002) between screw types. The axial tensile strength of the SR-PLLA screws (878 Newtons) was much lower than that achieved by the ASIF screws (8513 N). Subsequent testing in synthetic material again reflected significant differences (p <0.0001) between the screw types. The results may be accounted for by differences in the thread-to-core ratio between the screw types. Other factors, such as elastic deformation of the bioabsorbable screw, may also contribute through differences in the mechanical interface between screw and media.

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Axial Triangle of the Maxillary Sinus, and its Surgical Implication With the Position of Maxillary Sinus Septa During Sinus Floor Elevation: A CBCT Analysis

Journal of Oral Implantology ◽

10.1563/aaid-joi-d-18-00229 ◽

2020 ◽

Vol 46 (4) ◽

pp. 415-422

Author(s):

Junho Jung ◽

Jung Soo Park ◽

Seoung-Jin Hong ◽

Gyu-Tae Kim ◽

Yong-Dae Kwon

Keyword(s):

Maxillary Sinus ◽

Surgical Techniques ◽

Lateral Sinus ◽

Sinus Floor Elevation ◽

Second Molar ◽

Sinus Wall ◽

Posterior Maxilla ◽

Significant Difference ◽

Sinus Floor ◽

Molar Region

The aim of this study was to measure the convexity of the lateral wall of the maxillary (Mx) sinus and identify the locational distribution of antral septa in relation to the zygomaticomaxillary buttress (ZMB), in order to suggest another anatomical consideration and surgical modification of sinus floor elevation procedures. This study was designed as a cross-sectional study, and a total of 134 patients and 161 sinuses containing edentulous alveolar ridges were analyzed. The angle between the anterior and lateral walls of the Mx sinus (lateral sinus angle [LSA]), and the angle between the midpalatal line and the anterior sinus wall (anterior sinus angle [ASA]) were measured. Mean LSAs and ASAs were 105.9° ± 9.86° and 58.4° ± 6.43°, respectively. No significant difference between left and right sides was found (LSA, P = .420; right = 105.5° ± 9.27°; left = 105.5° ± 9.27° and ASA, P = .564; right = 57.9° ± 6.80°; left = 58.8° ± 6.02°). The prevalence of septa was 37.3%, and it was most frequently noted in the second molar region (32.8%), followed by the first molar (20.9%), retromolar (16.4%), and second premolar regions (14.9%). Septa were most frequently located posterior to the ZMB (49.2%), while ZMB was mostly located in the first molar region (66.4%). Narrow LSAs may complicate the surgical approach to the posterior maxilla, especially when sinus elevation should be used in the second molar region. Considering the occasional presence of antral septa, membrane elevation may be complicated when a septum is encountered during the procedure. These results suggest that 3-dimensional examination of the convexity of the Mx sinus should be performed preoperatively to choose proper surgical techniques and minimize surgical complications.

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The Influence of Force Direction on the Fracture Pattern and Fracture Resistance of Canine Teeth in Dogs

Journal of Veterinary Dentistry ◽

10.1177/0898756417705229 ◽

2017 ◽

Vol 34 (1) ◽

pp. 8-17 ◽

Cited By ~ 2

Author(s):

Stephanie Goldschmidt ◽

Catherine Zimmerman ◽

Caitlyn Collins ◽

Scott Hetzel ◽

Heidi-Lynn Ploeg ◽

...

Keyword(s):

Fracture Resistance ◽

Ex Vivo ◽

Testing Machine ◽

Fracture Pattern ◽

Hard Tissue ◽

Canine Tooth ◽

Cross Sectional ◽

Significant Difference ◽

Force Direction ◽

Testing Group

Biomechanical studies of the elongated canine tooth of animals are few, and thus our understanding of mechanical and physical properties of animal teeth is limited. The objective of the present study was to evaluate the influence of force direction on fracture resistance and fracture pattern of canine teeth in an ex vivo dog cadaver model. Forty-five extracted canine teeth from laboratory beagle dogs were standardized by hard tissue volume and randomly distributed among 3 force direction groups. The teeth were secured within a universal testing machine and a load was applied at different directions based on testing group. The maximum force to fracture and the fracture pattern classification were recorded for each tooth. After correcting for hard tissue cross-sectional area in a multivariate analysis, no significant difference in the amount of force required for fracture was apparent between the different force direction groups. However, the influence of force direction on fracture pattern was significant. The results of this study may allow the clinician to educate clients on possible causal force directions in clinically fractured teeth and, thus, help prevent any contributing behavior in the future.

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Trans-obturator cable fixation of open book pelvic injuries

Scientific Reports ◽

10.1038/s41598-021-92755-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Martin C. Jordan ◽

Veronika Jäckle ◽

Sebastian Scheidt ◽

Fabian Gilbert ◽

Stefanie Hölscher-Doht ◽

...

Keyword(s):

Pelvic Ring ◽

Testing Machine ◽

Biomechanical Testing ◽

Pubic Symphysis ◽

Cadaver Study ◽

Steel Cable ◽

Reliable Technique ◽

Peak Displacement ◽

Total Displacement ◽

Cable Fixation

AbstractOperative treatment of ruptured pubic symphysis by plating is often accompanied by complications. Trans-obturator cable fixation might be a more reliable technique; however, have not yet been tested for stabilization of ruptured pubic symphysis. This study compares symphyseal trans-obturator cable fixation versus plating through biomechanical testing and evaluates safety in a cadaver experiment. APC type II injuries were generated in synthetic pelvic models and subsequently separated into three different groups. The anterior pelvic ring was fixed using a four-hole steel plate in Group A, a stainless steel cable in Group B, and a titan band in Group C. Biomechanical testing was conducted by a single-leg-stance model using a material testing machine under physiological load levels. A cadaver study was carried out to analyze the trans-obturator surgical approach. Peak-to-peak displacement, total displacement, plastic deformation and stiffness revealed a tendency for higher stability for trans-obturator cable/band fixation but no statistical difference to plating was detected. The cadaver study revealed a safe zone for cable passage with sufficient distance to the obturator canal. Trans-obturator cable fixation has the potential to become an alternative for symphyseal fixation with less complications.

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Comparative Evaluation of Fracture Resistance of Endodontically Treated Teeth Restored with Resin Fiber Post and Stainless Steel Post: An In Vitro Study

Dental Journal of Advance Studies ◽

10.1055/s-0038-1672019 ◽

2015 ◽

Vol 03 (02) ◽

pp. 080-084

Author(s):

Vijay Singh ◽

Poonam Bogra ◽

Saurabh Gupta ◽

Navneet Kukreja ◽

Neha Gupta

Keyword(s):

Stainless Steel ◽

Fracture Resistance ◽

Testing Machine ◽

Compressive Force ◽

Control Group ◽

Fiber Post ◽

Endodontically Treated Teeth ◽

Group I ◽

Significant Difference

AbstractFracture resistance of endodontically treated teeth restored with post. Aims: This study aims to compare the fracture resistance of endodontically treated teeth restored with resin fiber and stainless steel post. Commercially available prefabricated resin fiber post(Dentsply Maillefer Easy Post), prefabricated stainless steel post(Coltene/Whaledent Parapost) were used. Methods and Material: Forty five maxillary central incisors were obturated and divided into 3 groups: Control Group (Group I) without any post (n = 15), Resin Fiber Post Group (Group II) (n = 15) and Stainless Steel Post Group (Group III) (n = 15). In all Groups except control group, post space was prepared; a post was cemented, and a core build-up was provided. All the specimens were subjected to compressive force under a universal testing machine until fracture. Statistical analysis used: The results were analyzed using the variable analysis test (ANOVA). Results: One-way analysis of variance revealed significant difference among test groups. The control group demonstrated highest fracture resistance (925.2183 N), followed by the resin fiber post group (486.7265 N) and stainless steel post group (423.539N). Conclusions: Teeth restored with resin fiber post showed higher fracture resistance values than prefabricated stainless steel post.

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Shear bond strength of novel calcium aluminate-based cement (EndoBinder) to root dentine

European Journal of Dentistry ◽

10.4103/1305-7456.143632 ◽

2014 ◽

Vol 08 (04) ◽

pp. 498-503 ◽

Cited By ~ 1

Author(s):

Lucas da Fonseca Roberti Garcia ◽

Hebert Luis Rossetto ◽

Fernanda de Carvalho Panzeri Pires-de-Souza

Keyword(s):

Bond Strength ◽

Calcium Aluminate ◽

Shear Bond Strength ◽

Testing Machine ◽

Mineral Trioxide Aggregate ◽

Acrylic Resin ◽

Promising Alternative ◽

Mean Values ◽

Significant Difference ◽

Molar Teeth

ABSTRACT Objective: To evaluate the shear bond strength of a novel calcium aluminate-based cement, EndoBinder (EB), to dentine in comparison with Grey and White Mineral Trioxide Aggregate (MTA). Materials and Methods: Root canal hemi-sections obtained from 30 extracted molar teeth were embedded in self-polymerized acrylic resin and were grounded wet in order to obtain a flat dentine surface. Next, the roots were randomly assigned into three groups (n = 10), according to the cement used, as follows: EB: EndoBinder; WMTA: White MTA and GMTA: Grey MTA. The shear bond strength test was performed using a Universal Testing Machine (0.5 mm/min) and the data were submitted to statistical analysis (1-way ANOVA and Tukey tests, P < 0.05). Results: EB presented the highest shear bond strength values; however, there was no statistically significant difference in comparison with GMTA (P > 0.05). WMTA presented the lowest mean values, which were significant in comparison with EB (P < 0.05). Conclusions: The novel calcium aluminate-based cement presented higher shear bond strength than WMTA, and should be considered as a promising alternative in endodontic therapy.

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Influence of rigidity of retainers on dynamic behavior of implant-supported removable partial dentures

International Journal of Implant Dentistry ◽

10.1186/s40729-020-00260-4 ◽

2020 ◽

Vol 6 (1) ◽

Author(s):

Toshifumi Nogawa ◽

Masayasu Saito ◽

Naomichi Murashima ◽

Yoshiyuki Takayama ◽

Atsuro Yokoyama

Keyword(s):

Dynamic Behavior ◽

Horizontal Displacement ◽

Vertical Displacement ◽

Denture Base ◽

Second Molar ◽

Mechanical Simulation ◽

Computed Tomography Images ◽

Significant Difference ◽

Abutment Teeth ◽

Distal Extension

Abstract Background Implant-supported removable partial dentures (ISRPDs) are an effective treatment for partially edentulous patients. ISRPDs improve patients’ satisfaction and oral function to a greater extent than RPDs by improving denture stability and enhancing support. However, the effect of a type of direct retainer on displacement of the abutment teeth and dentures in ISRPDs remains unclear. Therefore, we made a resin mandibular model of unilateral mandibular distal-extension partial edentulism for mechanical simulation and compared the dynamic behavior of the abutment teeth and the denture base among different tooth-borne retainers with various rigidities for RPDs and ISRPDs. Methods A resin mandibular model for mechanical simulation that had unilateral mandibular distal-extension edentulism and was missing the first molar, second molar, first premolar, and second premolar, and a denture fabricated from the patient’s computed tomography images were used. Three types of direct retainers with different connecting rigidities were evaluated. The vertical displacement of the denture base and buccal and lingual sides and the mesial displacement of the abutment teeth were measured. Results Regardless of the rigidity of the direct retainers and loading positions, the displacement of the denture bases in the ISRPDs was significantly smaller than that in the RPDs (P < 0.001). There was no significant difference in vertical displacement of the denture bases among direct retainers with various connecting rigidities in the ISRPDs. Conversely, horizontal displacement of the abutment teeth in both the RPDs and ISRPDs tended to be larger with the cone crown telescope, which has high rigidity, than with the cast cingulum rest and wire clasp, which have much lower rigidities. Conclusion Our results suggested that cast cingulum rest and wire clasps as direct retainers are appropriate ISRPDs to minimize denture movement and suppress displacement of the remaining teeth in patients with unilateral mandibular distal-extension partial edentulism.

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Effect of Using Nano and Micro Airborne Abrasive Particles on Bond Strength of Implant Abutment to Prosthesis

Brazilian Dental Journal ◽

10.1590/0103-6440201300173 ◽

2015 ◽

Vol 26 (1) ◽

pp. 50-55 ◽

Cited By ~ 2

Author(s):

Mansour Rismanchian ◽

Amin Davoudi ◽

Elham Shadmehr

Keyword(s):

Bond Strength ◽

Testing Machine ◽

Control Group ◽

Abrasive Particles ◽

Significant Difference ◽

Implant Abutments ◽

Implant Abutment ◽

Roughened Surface ◽

Bond Strengths ◽

Spss Software

Connecting prostheses to the implant abutments has become a concern and achieving a satisfactory retention has been focused in cement-retention prostheses recently. Sandblasting is a method to make a roughened surface for providing more retention. The aim of this study was to compare effects of nano and micro airborne abrasive particles (ABAP) in roughening surface of implant abutments and further retention of cemented copings. Thirty Xive abutments and analogues (4.5 D GH1) were mounted vertically in self-cured acrylic blocks. Full metal Ni-Cr copings with a loop on the top were fabricated with appropriate marginal adaptation for each abutment. All samples were divided into 3 groups: first group (MPS) was sandblasted with 50 µm Al2O3 micro ABAP, second group (NSP) was sandblasted with 80 nm Al2O3 nano ABAP, and the third group (C) was assumed as control. The samples were cemented with provisional cement (Temp Bond) and tensile bond strength of cemented copings was evaluated by a universal testing machine after thermic cycling. The t test for independent samples was used for statistical analysis by SPSS software (version 15) at the significant level of 0.05. Final result showed significant difference among all groups (p<0.001) and MPS manifested the highest mean retention (207.88±45.61 N) with significant difference among other groups (p<0.001). The control group showed the lowest bond strength as predicted (48.95±10.44 N). Using nano or micro ABAP is an efficient way for increasing bond strengths significantly, but it seems that micro ABAP was more effective.

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