scholarly journals Force Magnitude and Duration Effects on Amount of Tooth Movement and Root Resorption in the Rat Molar

2008 ◽  
Vol 78 (3) ◽  
pp. 502-509 ◽  
Author(s):  
Carmen Gonzales ◽  
Hitoshi Hotokezaka ◽  
Masako Yoshimatsu ◽  
Joseph H. Yozgatian ◽  
M. Ali Darendeliler ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Tooth Movement ◽  
Root Resorption ◽  
Three Dimensional ◽  
Nickel Titanium ◽  
Second Molar ◽  
Force Application ◽  
Surface Areas ◽  
Force Magnitude ◽  
Group A

Abstract Objective: To test the hypothesis that there is no difference in the effect of different continuous moderate to very heavy forces on root resorption or amount of tooth movement. Materials and Methods: In the study, 10, 25, 50 and 100 g mesial force were applied to the maxillary first molars of rat using nickel titanium closed-coil springs for 3 days, 14 days, and 28 days. The molars were extracted and the surface areas of the root resorption craters were measured using scanning electron microscope. The depths of the root resorption craters were measured using a three-dimensional laser scanning microscope. Tooth movement of the maxillary first molar was measured in relation to the maxillary second molar on digitized lateral cephalometric radiographs. Results: Three days after force application, the tooth movement was not proportionally related to force magnitude. However, 14 days of force application resulted in significantly more tooth movement in the 10, 25, and 50 g force groups than in the 100 g force group. A force application of 10 g produced significantly more tooth movement at 28 days than all the other three force applications. The largest and deepest resorption craters were observed in the disto-buccal root followed by disto-palatal, middle-buccal, middle-palatal, and mesial root. Root resorption and tooth movement increased over time from 3 to 28 days. As heavier forces were applied, greater root resorption occurred. Conclusion: The hypothesis is rejected. The light mesially oriented forces, as applied in this study, produced more tooth movement and less root resorption compared with heavier forces.

Effects of diabetes on tooth movement and root resorption after orthodontic force application in rats

2016 ◽  
Vol 19 (2) ◽  
pp. 83-92 ◽  
Author(s):  
K. Arita ◽  
H. Hotokezaka ◽  
M. Hashimoto ◽  
T. Nakano-Tajima ◽  
T. Kurohama ◽  
...  
Keyword(s):  
Tooth Movement ◽  
Root Resorption ◽  
Orthodontic Force ◽  
Force Application

scholarly journals Effect of continuous versus intermittent orthodontic forces on root resorption: A microcomputed tomography study

2018 ◽  
Vol 88 (6) ◽  
pp. 733-739 ◽  
Author(s):  
Nurhat Ozkalayci ◽  
Ersan Ilsay Karadeniz ◽  
Selma Elekdag-Turk ◽  
Tamer Turk ◽  
Lam L. Cheng ◽  
...  
Keyword(s):  
Tooth Movement ◽  
Root Resorption ◽  
Experimental Period ◽  
Microcomputed Tomography ◽  
Orthodontic Force ◽  
Rotational Movement ◽  
Force Application ◽  
Orthodontic Forces ◽  
Intermittent Regimen

ABSTRACT Objectives: To compare the extent of root resorption and the amount of tooth movement between continuous orthodontic force and intermittent orthodontic force that was activated in a similar way to a 4-week orthodontic adjustment period. Materials and Methods: Twenty-five patients who required the extraction of upper first premolars were recruited in this study. A buccally directed continuous force of 150 g was applied to the upper first premolar on one side for 15 weeks. A buccally directed intermittent force (28 days on, 7 days off) of the same magnitude was applied to the contralateral first premolar. The teeth were extracted at the end of the experimental period and processed for volumetric evaluations of resorption craters. The degree of tooth movement and rotation were measured on the study models. Results: Continuous force application displayed significantly higher root resorption volume than the intermittent force application (P < .05), particularly on the buccal and lingual surfaces (P < .05) and the middle third of the root (P < .01). There was more tipping and rotational movement in the continuous force group. Conclusions: In a 4-week orthodontic adjustment period, intermittent force significantly reduced the amount of root resorption compared with continuous force. Although there was less degree of tooth movement with intermittent force, unwanted rotational movement was avoided. This is crucial in patients who are predisposed to orthodontically induced inflammatory root resorption, and the use of this intermittent regimen should be considered.

scholarly journals Characterization of Biofilm Formation by Clinically Relevant Serotypes of Group A Streptococci

2006 ◽  
Vol 72 (4) ◽  
pp. 2864-2875 ◽  
Author(s):  
Cordula Lembke ◽  
Andreas Podbielski ◽  
Carlos Hidalgo-Grass ◽  
Ludwig Jonas ◽  
Emanuel Hanski ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Laser Scanning ◽  
Group A Streptococcus ◽  
Three Dimensional ◽  
Positive Control ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Subsequent Formation ◽  
Group A

ABSTRACT Streptococcus pyogenes (group A streptococcus [GAS]) is a frequent cause of purulent infections in humans. As potentially important aspects of its pathogenicity, GAS was recently shown to aggregate, form intratissue microcolonies, and potentially participate in multispecies biofilms. In this study, we show that GAS in fact forms monospecies biofilms in vitro, and we analyze the basic parameters of S. pyogenes in vitro biofilm formation, using Streptococcus epidermidis as a biofilm-positive control. Of nine clinically important serotype strains, M2, M6, M14, and M18 were found to significantly adhere to coated and uncoated polystyrene surfaces. Fibronectin and collagen types I and IV best supported primary adherence of serotype M2 and M18 strains, respectively, whereas serotype M6 and M14 strains strongly bound to uncoated polystyrene surfaces. Absorption measurements of safranin staining, as well as electron scanning and confocal laser scanning microscopy, documented that primary adherence led to subsequent formation of three-dimensional biofilm structures consisting of up to 46 bacterial layers. Of note, GAS isolates belonging to the same serotype were found to be very heterogeneous in their biofilm-forming behavior. Biofilm formation was equally efficient under static and continuous flow conditions and consisted of the classical three steps, including partial disintegration after long-term incubation. Activity of the SilC signaling peptide as a component of a putative quorum-sensing system was found to influence the biofilm structure and density of serotype M14 and M18 strains. Based on the presented methods and results, standardized analyses of GAS biofilms and their impact on GAS pathogenicity are now feasible.

scholarly journals Effects of Steroidal and Nonsteroidal Drugs on Tooth Movement and Root Resorption in the Rat Molar

2009 ◽  
Vol 79 (4) ◽  
pp. 715-726 ◽  
Author(s):  
Carmen Gonzales ◽  
Hitoshi Hotokezaka ◽  
Ken-Ichiro Matsuo ◽  
Tatsunori Shibazaki ◽  
Joseph H. Yozgatian ◽  
...  
Keyword(s):  
Tooth Movement ◽  
Root Resorption ◽  
Three Dimensional ◽  
Negative Control Group ◽  
Treated Group ◽  
Negative Control ◽  
Control Group ◽  
High Dose ◽  
Experimental Control ◽  
Male Wistar Rats

Abstract Objective: To test the hypothesis that the administration of aspirin, acetaminophen, meloxicam, celecoxib, and prednisolone have no effect on root resorption and tooth movement. Materials and Methods: A mesial force of 50 g was applied to the left maxillary first molars of sixty 10-week-old male Wistar rats using nickel titanium closed coil springs attached to the cervical area of the incisors. The rats were randomly divided into 12 groups of 5 each. High and low doses of aspirin, acetaminophen, meloxicam, celecoxib, and prednisolone were administered via drinking water for 2 weeks. The experimental control group had tooth movement but received no drug. The negative control group received neither tooth movement nor drugs. The amount of tooth movement was measured on digitized lateral cephalometric radiographs. Rats were sacrificed after 2 weeks. Mesial and distal roots (distobuccal and distopalatal) were examined using scanning electron and three-dimensional (3D) scanning laser microscopes. The surface area, depth, volume, and roughness of the root resorption craters were measured. Results: When compared with experimental control rats, only prednisolone- and high-dose celecoxib-treated groups showed significantly less root resorption and less tooth movement. Although low dose celecoxib-treated group significantly decreased the tooth movement, root resorption was similar to the control group. Furthermore, resorption craters showed a smoother surface in the prednisolone-treated rats. Conclusions: The hypothesis was rejected. Administration of prednisolone and high-dose celecoxib reduces root resorption and interferes with tooth movement in rats. Both drugs may interfere in the arachidonic acid cascade depending on dose thresholds.

Three-dimensional mechanical environment of orthodontic tooth movement and root resorption

2008 ◽  
Vol 133 (6) ◽  
pp. 791.e11-791.e26 ◽  
Author(s):  
Rodrigo F. Viecilli ◽  
Thomas R. Katona ◽  
Jie Chen ◽  
James K. Hartsfield ◽  
W. Eugene Roberts
Keyword(s):  
Tooth Movement ◽  
Root Resorption ◽  
Three Dimensional ◽  
Orthodontic Tooth Movement ◽  
Mechanical Environment

scholarly journals Orthodontic Buccal Tooth Movement by Nickel-Free Titanium-Based Shape Memory and Superelastic Alloy Wire

2006 ◽  
Vol 76 (6) ◽  
pp. 1041-1046 ◽  
Author(s):  
Akihiro Suzuki ◽  
Hiroyasu Kanetaka ◽  
Yoshinaka Shimizu ◽  
Ryo Tomizuka ◽  
Hideki Hosoda ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shape Memory ◽  
Tooth Movement ◽  
Orthodontic Tooth Movement ◽  
Nickel Titanium ◽  
Alloy Wire ◽  
Force Magnitude ◽  
Niobium Aluminum ◽  
Initial Force ◽  
Continuous Progression

Abstract Objective: To examine the mechanical properties and the usefulness of titanium-niobium-aluminum (Ti-Nb-Al) wire in orthodontic tooth movement as compared with nickel-titanium (Ni-Ti) wire. Materials and Methods: The load deflection of expansion springs was gauged with an original jig. The gradient of the superelastic region was measured during the unloading process. Expansion springs comprising the two types of alloy wires were applied to upper first molars of rats. The distance between the first molars was measured with micrometer calipers. Results: The force magnitude of the Ti-Nb-Al expansion spring was lower than that of the Ni-Ti expansion spring over the entire deflection range. The initial force magnitude and the gradient in the superelastic region of the Ti-Nb-Al expansion springs were half those of the Ni-Ti expansion springs. Thus, Ti-Nb-Al expansion springs generated lighter and more continuous force. Tooth movement in the Ni-Ti group proceeded in a stepwise fashion. On the other hand, tooth movement in the Ti-Nb-Al group showed relatively smooth and continuous progression. At 17 days after insertion of expansion springs, there were no significant differences between the Ti-Nb-Al and Ni-Ti groups in the amount of tooth movement. Conclusions: These results indicate that Ti-Nb-Al wire has excellent mechanical properties for smooth, continuous tooth movement and suggest that Ti-Nb-Al wire may be used as a practical nickel-free shape memory and superelastic alloy wire for orthodontic treatment as a substitute for Ni-Ti wire.

The Finite Element Analysis of Stress in the Periodontal Ligament when Subject to Vertical Orthodontic Forces

1994 ◽  
Vol 21 (2) ◽  
pp. 161-167 ◽  
Author(s):  
A. N. Wilson ◽  
J. Middleton ◽  
M. L. Jones ◽  
N. J. McGuinness
Keyword(s):  
Finite Element ◽  
Periodontal Ligament ◽  
Tooth Movement ◽  
Root Resorption ◽  
Three Dimensional ◽  
Element Model ◽  
Vertical Movement ◽  
Optimum Level ◽  
Element Analysis ◽  
Three Dimensional Finite Element

In the past, vertical intrusive movement of teeth has been considered difficult and most routine clinical vertical movement of teeth has been confined to extrusion. It has been suggested that attempts at intrusion may result in an increased incidence of root resorption and also in occasional devitalization. The displacement and resulting stress fields associated with such treatment can be successfully studied using the finite element method. In the case being considered initial movements are known to be small; therefore, the assumption in the study that the material behaves linear-elastically is considered to be reasonable. This study of vertical tooth movement demonstrated that the maximum cervical margin stress in the periodontal ligament was 0·0046 N/mm2, whilst the highest apical stress was 0·00205 N/mm2 when intrusive and extrusive forces of 1 Newton were applied to the buccal surface of the crown of a tooth model. These stresses were evaluated in the light of previous studies and found to be within the suggested clinical optimum level. However, the periodontal stress distribution following orthodontic loading within this three-dimensional finite element model was found to be highly complex.

The Effect of Time and Force Magnitude on Orthodontic Tooth Movement

1979 ◽  
Vol 58 (8) ◽  
pp. 1754-1764 ◽  
Author(s):  
Ryszard J. Pryputniewicz ◽  
Charles J. Burstone
Keyword(s):  
Tooth Movement ◽  
Three Dimensional ◽  
Orthodontic Tooth Movement ◽  
Applied Force ◽  
Experimental Results ◽  
Three Dimensions ◽  
Human Teeth ◽  
Force System ◽  
Force Magnitude

The holographic technique, recently developed for precise and accurate measurement of tooth displacements, was used to study the three-dimensional motion of human teeth. Maxillary central incisors were loaded with forces of 300 grams and 500 grams. Translations and rotations in three-dimensions were measured over 45 seconds. The experimental results, presented as a function of time, indicate that the instantaneous centers of rotation can be represented by space centrodes that are characteristic for each patient and the applied force system.

scholarly journals Correlation of IL-17 level in gingival crevicular fluid of orthodontically induced inflammatory root resorption

2019 ◽  
Author(s):  
Hua Zhou ◽  
Xiao Liang ◽  
Aipeng Liu ◽  
Dongmei Nong ◽  
Yaqing Qin ◽  
...  
Keyword(s):  
Alveolar Bone ◽  
Tooth Movement ◽  
Root Resorption ◽  
Early Stage ◽  
Morphological Changes ◽  
Orthodontic Tooth Movement ◽  
Nickel Titanium ◽  
Tartrate Resistant Acid Phosphatase ◽  
Periodontal Tissues ◽  
Osteoclast Number

ABSTRACTObjectiveTo investigate IL-17 expression in orthodontic tooth movement and orthodontic nickel-titanium spring-induced inflammatory root resorption.MethodsOrthodontic nickel-titanium springs were ligated between the bilateral maxillary first molar and the incisors of the rats to establish a rat model of orthodontic tooth movement (OTM), each rat was subjected to two cycles of near-GCF and peripheral blood serum collection before and after force application, and IL-17 levels in GCF and serum were measured quantitatively by ELISA. Morphological changes in periodontal tissue and root of the experimental dentine were evaluated by hematoxylin and eosin staining. Tartrate-resistant acid phosphatase staining and immunohistochemistry were used to determine the osteoclast number and expression changes in IL-17, receptor activator of nuclear factor kappa-B ligand (RANKL), and osteoprotegerin (OPG) in the periodontal tissues, respectively, on the pressure side of the experimental tooth.ResultsIL-17 was detected in GCF and serum. The pressure area exhibited alveolar bone resorption only at a force of 20g. Additionally, a force of 60g led to root resorption. IL-17, RANKL/OPG and osteoclast number showed similar trend that all expressed increasing high level at early stage, then significantly decreased from days 5 to 14, and revealed 60g group the highest expression level while 0g group the lowest.The change in the IL-17 level in the GCF was strongly correlated with IL-17 and RANKL/OPG expression levels and osteoclast numbers in the periodontal ligament.ConclusionsThe results indicated that measuring IL-17 level in GCF can predict the risk of alveolar bone and root resorption induced by orthodontic treatment.

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