scholarly journals RANKL and OPG expression: Jiggling force affects root resorption in rats

2016 ◽  
Vol 87 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Yayoi Matsuda ◽  
Masahide Motokawa ◽  
Masato Kaku ◽  
Hiromi Sumi ◽  
Kazuo Tanne ◽  
...  

ABSTRACT Objective: To immunohistochemically investigate the longitudinal changes in root resorption by jiggling force in experimental animal models. Materials and Methods: Fifty-six 12-week-old male Wistar rats were used. The maxillary first molars were alternately moved in the buccal and lingual direction in 28 rats (experimental group) using an experimental appliance to produce jiggling forces of 10 g. In another 28 rats (control group), the maxillary first molars were moved in only the lingual direction with a force of 10 g. After 1, 3, 7, 10, 14, 17, and 21 days, the maxillae were resected and subjected to immunohistochemical analysis. The resorption area was quantified histomorphometrically and the number of odontoclasts on the root surface was counted. Expression of RANKL and OPG was also examined by immunohistochemical staining. Results: The root resorption area and the number of odontoclasts were significantly greater in the experimental group than in controls. Odontoclasts were detected in the resorption lacunae and PDL in the experimental group, whereas osteoclasts were located only along the alveolar bone in controls. OPG was detected on the alveolar bone in the experimental group and on the root surfaces of the controls. Conclusions: Jiggling force is a critical factor in severe root resorption, affecting RANKL and OPG expression, which accelerates and inhibits odontoclastic induction, respectively.

2005 ◽  
Vol 284-286 ◽  
pp. 851-854 ◽  
Author(s):  
D.H. Min ◽  
M.J. Kim ◽  
J.H. Yun ◽  
C.S. Kim ◽  
Yong Keun Lee ◽  
...  

This study evaluated periodontal repair and biomaterial reaction following implantation of a newly fabricated calcium phosphate block bone with chitosan membrane on the regeneration of 1-wall intrabony defects in the beagle dogs. The surgical control group received a flap operation only, while the experimental group I was treated with a chitosan nonwoven membrane only and the experimental group II was treated with a chitosan nonwoven membrane and a calcium phosphate block bone. The subjects were sacrificed 12 weeks after surgery and a comparative histometric analysis was done. No root resorption or ankylosis were observed in the experimental group. Mann-Whitney U test showed that the experimental group II produced statistically significant higher gain in connective tissue adhesion, new cementum regeneration and new bone formation. Based on histological results, the calcium phosphate block bone successfully functioned as a osteoconductive scaffold for invading cells of host.


2018 ◽  
Vol 88 (4) ◽  
pp. 425-434 ◽  
Author(s):  
Papatpong Phermsang-ngarm ◽  
Chairat Charoemratrote

ABSTRACT Objectives: To compare tooth movement achieved, time required for alignment, root resorption, and alveolar bone thickness changes during initial dental alignment between groups treated with 0.012-inch preformed heat-activated or customized nickel titanium (NiTi) archwires. Materials and Methods: Thirty-two subjects (mean age 19.8 ± 1.7 years) with severe crowding of maxillary anterior teeth had premolar extractions and were randomly allocated into control and experimental groups receiving preformed heat-activated and customized NiTi archwires, respectively. Limited field of view cone-beam computed tomographies were taken initially (T0) and three months after final alignment (TF) to evaluate bone changes. Digital model analysis assessed tooth movement at monthly intervals. Time to achieve alignment was assessed in months. Wilcoxon signed-rank tests and Mann–Whitney U-tests were used to compare changes within and between groups, as appropriate. Results: Central incisor tooth movement was significantly different (all P ≤ .003) between groups at all time points. TF-T0 showed labial movement (0.75 ± 1.42 mm) in the control group and palatal movement (−0.96 ± 0.41 mm) in the experimental group. The experimental compared to control group showed significantly more canine distal movement (0.60 ± 0.28 mm; P ≤ .049), less labial bone thickness changes (P ≤ .004), less root resorption of the central and lateral incisors (P ≤ .007), and a longer time to achieve alignment (P = .01). Conclusions: The experimental group exhibited palatal movement of the central incisors, more canine distal movement with less bone thickness changes, and less root resorption but took more time to achieve alignment than the control group.


2012 ◽  
Vol 83 (3) ◽  
pp. 425-430 ◽  
Author(s):  
Kunaal Dhingra ◽  
Kharidhi Laxman Vandana ◽  
Polavaram Vasudeva Girish ◽  
Charles Cobb

ABSTRACT Objective: To evaluate and compare the root surface morphological changes after 980-nm diode laser–aided circumferential supracrestal fiberotomy (CSF) on fluorosed and non-fluorosed teeth. Materials and Methods: The sample comprised 27 orthodontic patients (14 males and 13 females; mean age  =  17.3 years) with and without fluorosis, from whom 40 fluorosed and 40 non-fluorosed premolar teeth were extracted for orthodontic reasons. Conventional (control group) and laser-aided (experimental group) CSF was performed on fluorosed and non-fluorosed teeth indicated for orthodontic extraction, using a scalpel and a 980-nm diode laser at 2.5 W power, respectively. Subsequently, teeth were extracted, sectioned, and examined by scanning electron microscope to assess the ultrastructural changes. Results: There were differences in surface morphology among fluorosed and non-fluorosed roots in the control group. The root specimens of both fluorosed and non-fluorosed teeth irradiated by diode laser exhibited no evidence of smear layer, laser-induced pitting or cavitation, linear cuts/markings, carbonization of surface, and heat-induced surface cracking. However, a glazed or slightly melted appearance was observed in root specimens of fluorosed teeth after diode laser irradiation. Conclusions: These findings suggest that the diode laser–aided CSF procedure is free from thermal hazard on non-fluorosed root surfaces but may provoke some thermal changes on fluorosed root surfaces.


2011 ◽  
Vol 26 (6) ◽  
pp. 426-432
Author(s):  
Reginaldo Inojosa Carneiro Campello ◽  
Belmiro Cavalcanti do Egito Vasconcelos ◽  
Gerhilde Callou Sampaio ◽  
Antonio Rolim ◽  
Gabriela Granja Porto

PURPOSE: To evaluate the bone healing of mandibular fractures following the use of Portland cement. METHODS: Thirty-two male Wistar rats were divided into control and experimental groups. In the control group the rats were submitted to a mandibular fracture, which was reduced, and the soft tissues were sutured. In the experimental group the rats had the mandibular fracture reduced and maintained with the Portland cement. The animals were euthanized 7 and 21 days after surgery by injecting a lethal dose of anesthetic. The following variables were studied: weight of the animals, radiographic images, histopathological features and time of surgery. RESULTS: A weight loss was observed in the specimens of both groups at the different times of evaluation, a greater difference in weight before and after surgery being found in the experimental group, which was statistically significant (p <0.05, p = 0.041). From the histological point of view, with a margin of error (5.0%) the only two significant differences (p <0.05) recorded in the variables were "Material deployed" and "Bone resorption" during the evaluations at 7 and 21 days, respectively. CONCLUSION: The Portland cement served to promote bone healing.


2015 ◽  
Vol 86 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Débora C Martins ◽  
Bernardo Q Souki ◽  
Paula L Cheib ◽  
Gerluza A.B Silva ◽  
Igor D.G Reis ◽  
...  

ABSTRACT Objective:  To compare external root resorption (ERR) when bands and wires are used as orthodontic anchorage during rapid maxillary expansion (RME). Materials and Methods:  Histologic analysis was performed on 108 sites from 18 maxillary first premolars and on 36 sites from six mandibular first premolars in nine subjects (mean age = 15.2 ± 1.4 years) 3 months after RME. Maxillary teeth were pooled into two groups (n = 54 each) according to the type of orthodontic anchorage (band group [BG] vs wire group [WG]). Anchorage type was randomly chosen in a split-mouth design. Mandibular first premolars, which were not subjected to orthodontic forces, were used as the control group (CG). Results:  All premolars in the BG and WG showed ERR at the level of the cementum and dentin. Repair with cementum cells was observed in all resorption areas, but complete repair was rarely found. No statistically significant difference was found between the BG and WG with regard to the ERR. No association was found between the root height position (middle or cervical third) and the incidence of ERR. Buccal root surfaces showed a higher amount of ERR compared with the palatal and interproximal surfaces. ERR was not found in any teeth in the CG. Conclusion:  All maxillary first premolars subjected to RME showed ERR and partial cementum repair. Banded teeth did not develop more ERR than nonbanded anchorage teeth.


2015 ◽  
pp. 153-159 ◽  
Author(s):  
M. M. GOVENDER ◽  
A. NADAR

Oxidative stress is an imbalance between free radicals and antioxidants, and is an important etiological factor in the development of hypertension. Recent experimental evidence suggests that subpressor doses of angiotensin II elevate oxidative stress and blood pressure. We aimed to investigate the oxidative stress related mechanism by which a subpressor dose of angiotensin II induces hypertension in a normotensive rat model. Normotensive male Wistar rats were infused with a subpressor dose of angiotensin II for 28 days. The control group was sham operated and infused with saline only. Plasma angiotensin II and H2O2 levels, whole-blood glutathione peroxidase, and AT-1a, Cu/Zn SOD, and p22phox mRNA expression in the aorta was assessed. Systolic and diastolic blood pressures were elevated in the experimental group. There was no change in angiotensin II levels, but a significant increase in AT-1a mRNA expression was found in the experimental group. mRNA expression of p22phox was increased significantly and Cu/Zn SOD decreased significantly in the experimental group. There was no significant change to the H2O2 and GPx levels. Angiotensin II manipulates the free radical-antioxidant balance in the vasculature by selectively increasing O2− production and decreasing SOD activity and causes an oxidative stress induced elevation in blood pressure in the Wistar rat.


2013 ◽  
Vol 18 (4) ◽  
pp. 113-119 ◽  
Author(s):  
Milena Peixoto Nogueira de Sá ◽  
Jacqueline Nelisis Zanoni ◽  
Carlos Luiz Fernandes de Salles ◽  
Fabrício Dias de Souza ◽  
Uhana Seifert Guimarães Suga ◽  
...  

INTRODUCTION: The mandibular condylar surface is made up of four layers, i.e., an external layer composed of dense connective tissue, followed by a layer of undifferentiated cells, hyaline cartilage and bone. Few studies have demonstrated the behavior of the condylar cartilage when the mandible is positioned posteriorly, as in treatments for correcting functional Class III malocclusion. OBJECTIVE: The aim of this study was to assess the morphologic and histological aspects of rat condyles in response to posterior positioning of the mandible. METHODS: Thirty five-week-old male Wistar rats were selected and randomly divided into two groups: A control group (C) and an experimental group (E) which received devices for inducing mandibular retrusion. The animals were euthanized at time intervals of 7, 21 and 30 days after the experiment had began. For histological analysis, total condylar thickness was measured, including the proliferative, hyaline and hypertrophic layers, as well as each layer separately, totaling 30 measurements for each parameter of each animal. RESULTS: The greatest difference in cartilage thickness was observed in 21 days, although different levels were observed in the other periods. Group E showed an increase of 39.46% in the total layer, reflected by increases in the thickness of the hypertrophic (42.24%), hyaline (46.92%) and proliferative (17.70%) layers. CONCLUSIONS: Posteriorly repositioning the mandible produced a series of histological and morphological responses in the condyle, suggesting condylar and mandibular adaptation in rats.


2009 ◽  
Vol 79 (5) ◽  
pp. 978-983 ◽  
Author(s):  
Takayoshi Ishida ◽  
Tadachika Yabushita ◽  
Kunimichi Soma

Abstract Objective: To determine the influence of masseter muscle activity during growth on the functional characteristics of temporomandibular joint (TMJ) mechanoreceptors. Materials and Methods: Sixty-six 3-week-old male Wistar rats were divided into an experimental group, in which the masseter muscles were bilaterally resected at 3 weeks of age, and a control group. Single-unit activities of the TMJ mechanoreceptors were evoked by indirect stimulation of passive jaw movement. Electrophysiologic recordings of TMJ units were made at 5, 7, and 9 weeks of age. Results: During this period, the firing threshold of the TMJ units was significantly lower and the maximum instantaneous frequency of the TMJ units was significantly higher in the experimental group than in the control group. Conclusion: Reduced masseter activity during the growth period alters the response properties of TMJ mechanoreceptors.


2003 ◽  
Vol 17 (4) ◽  
pp. 319-325 ◽  
Author(s):  
José Eduardo Cezar Sampaio ◽  
Ricardo Samih Georges Abi Rached ◽  
Gibson Luiz Pilatti ◽  
Letícia Helena Theodoro ◽  
Luiz Henrique Carvalho Batista

The purpose of this study was to compare the removal of root surface smear layer following active application of EDTA gel and EDTA-T (texapon) gel in different concentrations (5%, 10%, 15%, 20% and 24%), using scanning electron microscopy. A total of 220 dentin blocks obtained from the root surfaces of extracted teeth were divided into 3 groups: Group I - (control) application of saline solution (n = 20); Group II - EDTA gel (pH 7.0) was applied in the following concentrations: 5%, 10%, 15%, 20% and 24% (n = 100); Group III - EDTA-T gel (pH 7.0) applied in the same concentrations described above (n = 100). The photomicrographs were evaluated by one calibrated examiner using a smear layer removal index and following statistical analysis (Kruskal-Wallis test). The results demonstrated that the specimens treated with EDTA and EDTA-T gel presented a better smear layer removal than the control group (p < 0.01); no statistically significant differences were observed between the EDTA and EDTA-T groups and between the concentrations tested (Mann-Whitney, p > 0.05). Within the limits of this study, it can be concluded that all treatment modalities effectively removed the smear layer from the root surface. The addition of texapon into the EDTA gel formulation did not increase its effectiveness.


2016 ◽  
Vol 21 (2) ◽  
pp. 65-72 ◽  
Author(s):  
Farzin Heravi ◽  
Hooman Shafaee ◽  
Ali Forouzanfar ◽  
Seyed Hossein Hoseini Zarch ◽  
Mohsen Merati

ABSTRACT Objective: The aim of this study was to evaluate the movement of impacted canines away from the roots of neighboring teeth before full-mouth bracket placement, performed by means of TADs to decrease undesired side effects on adjacent teeth. Methods: The study sample consisted of 34 palatally impacted canines, being 19 in the experimental group and 15 in the control group. In the experimental group, before placement of brackets, the impacted canine was erupted by means of miniscrews. In the control group, after initiation of comprehensive orthodontics, canine disimpaction was performed by means of a cantilever spring soldered to a palatal bar. At the end of treatment, volume of lateral incisors and canine root resorption were measured and compared by means of a CBCT-derived tridimensional model. Visual Analogue Scale (VAS) score, bleeding on probing (BOP) and gingival index (GI) were recorded. Clinical success rate was also calculated. Results: The volume of root resorption of lateral teeth in the control group was significantly greater than in the experimental group (p < 0.001). At the end of treatment, VAS score, GI and BOP were not significantly different between the two groups. Conclusion: Based on our results, it seems that disimpaction of canines and moving them to the arch can be done successfully carried out with minimal side effects by means of skeletal anchorage.


Sign in / Sign up

Export Citation Format

Share Document