scholarly journals Evaluation of biofilm colonization on multi-part dental implants in a rat model

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Eva Blank ◽  
Jasmin Grischke ◽  
Andreas Winkel ◽  
Joerg Eberhard ◽  
Nadine Kommerein ◽  
...  
Keyword(s):  
Dental Implants ◽  
Antibiotic Treatment ◽  
Bacterial Colonization ◽  
Laser Scanning Microscopy ◽  
Treatment Groups ◽  
Implant Materials ◽  
Custom Made ◽  
Group A ◽  
Group B

Abstract Background Peri-implant mucositis and peri-implantitis are highly prevalent biofilm-associated diseases affecting the tissues surrounding dental implants. As antibiotic treatment is ineffective to fully cure biofilm mediated infections, antimicrobial modifications of implants to reduce or prevent bacterial colonization are called for. Preclinical in vivo evaluation of the functionality of new or modified implant materials concerning bacterial colonization and peri-implant health is needed to allow progress in this research field. For this purpose reliable animal models are needed. Methods Custom made endosseous dental implants were installed in female Sprague Dawley rats following a newly established three-step implantation procedure. After healing of the bone and soft tissue, the animals were assigned to two groups. Group A received a continuous antibiotic treatment for 7 weeks, while group B was repeatedly orally inoculated with human-derived strains of Streptococcus oralis, Fusobacterium nucleatum and Porphyromonas gingivalis for six weeks, followed by 1 week without inoculation. At the end of the experiment, implantation sites were clinically assessed and biofilm colonization was quantified via confocal laser scanning microscopy. Biofilm samples were tested for presence of the administered bacteria via PCR analysis. Results The inner part of the custom made implant screw could be identified as a site of reliable biofilm formation in vivo. S. oralis and F. nucleatum were detectable only in the biofilm samples from group B animals. P. gingivalis was not detectable in samples from either group. Quantification of the biofilm volume on the implant material revealed no statistically significant differences between the treatment groups. Clinical inspection of implants in group B animals showed signs of mild to moderate peri-implant mucositis (4 out of 6) whereas the mucosa of group A animals appeared healthy (8/8). The difference in the mucosa health status between the treatment groups was statistically significant (p = 0.015). Conclusions We developed a new rodent model for the preclinical evaluation of dental implant materials with a special focus on the early biofilm colonization including human-derived oral bacteria. Reliable biofilm quantification on the implant surface and the symptoms of peri-implant mucositis of the bacterially inoculated animals will serve as a readout for experimental evaluation of biofilm-reducing modifications of implant materials.

Evaluation of the Effect of Ozonated Plant Oils on the Quality of Osseointegration of Dental Implants Under the Influence of Cyclosporin A: An In Vivo Study

2011 ◽  
Vol 37 (2) ◽  
pp. 247-257 ◽  
Author(s):  
Amany A. El Hadary ◽  
Hala H. Yassin ◽  
Sameh T. Mekhemer ◽  
Julian C. Holmes ◽  
Martin Grootveld
Keyword(s):  
Bone Density ◽  
Cyclosporin A ◽  
Dental Implants ◽  
Immunosuppressive Agents ◽  
Control Group ◽  
Term Administration ◽  
Group A ◽  
Group B

Abstract Immunosuppressive agents have been recognized as factors that induce changes and modifications in bone metabolism. The purpose of this study was to evaluate the effect of ozonated plant extracts (herein termed ozonated oil) under the influence of Cyclosporin A (CsA) on osseointegration. A total of 20 dental implants were placed in 20 rabbit tibiae assigned to Group A or B. CsA was injected at an immunosuppressive dose in Groups A and B as a single-dose treatment. At the day of surgery, Group A received a single topical ozonated oil treatment (0.55 mL) around dental implants; Group B, the control group, received no ozonated oil. Animals were sacrificed after 8 weeks. Radiographs were obtained at implant surgery and on the day of sacrifice. Bone quality was compared between the 2 groups. Radiographically, osseointegration was microscopically evaluated using scanning electron and light microscopies. In ozonated Group A specimens, light microscopic examination demonstrated evidence of more organized mature bone compared with Group B. Within the limits of this study, the results suggest that short-term administration of CsA, when administered with topical ozonated oil, may influence bone density and the quality of dental implant osseointegration. Therefore, topically applied ozonated oil may influence bone density and the quality of osseointegration around dental implants.

Can Kampo medicine prolong the life of metastatic colorectal cancer (MCRC) patients with chemotherapy?

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e15120-e15120
Author(s):  
K. Sasaki ◽  
K. Oono ◽  
K. Harada ◽  
T. Someya ◽  
Y. Takada ◽  
...  
Keyword(s):  
Low Cost ◽  
Survival Rates ◽  
Kampo Medicine ◽  
Tumor Characteristics ◽  
Treatment Groups ◽  
Anti Cancer ◽  
Group A ◽  
Group B

e15120 Background: Many in vivo and in vitro studies have shown that Kampo medicine has various biological and immunological activities, including anti-cancer effect. However, we have little data on efficacy of survival period on MCRC patients (pts) with chemotherapy and Kampo therapy. The aim of this study was to evaluate the survival benefit on MCRC pts treated with Kampo medicine and chemotherapy. Methods: From 2002 to 2007, we treated 66 patients with MCRC. These patients were treated with chemotherapy (CPT-11 + S-1) and/or Kampo medicine (Jyuzen-Taiho-To, TJ-48) on out-patient basis. TJ-48 was given orally at a dose of 7.5g, three times daily. We randomly divided the MCRC pts following two treatment groups; chemotherapy plus Kampo medicine (Group A, n=33) and chemotherapy only (Group B, n=33). Results: Pts and tumor characteristics were much the same between the two groups at baseline. Pts treated with Kampo medicine in combination with chemotherapy (Group A) had a median survival of 20.5 months compared with 15 months for Group B (p=0.12). One and 2 years survival rates were 72% and 13%. No toxic death was reported. The overall 1, 2 and 3 years survival rate were 69, 24 and 12% respectively in Group A, 57, 0 and 0% in Group B. Adverse events did not increase in Group A. TJ-48 is low cost medicine ($1.8 / day). All patients were treated on an out-patient clinic. Conclusions: These results confirmed that the Kampo medicine is helpful and capable of prolonging the survival periods in pts with MCRC. No significant financial relationships to disclose.

Survival of classic swine fever virus in hams made from the meat of pigs vaccinated with the PAV-250 strain and unvaccinated pigs

2019 ◽  
Vol 10 (3) ◽  
pp. 536-551
Author(s):  
Heidi Amezcua Hempel ◽  
María Salud Rubio Lozano ◽  
Eliseo Manuel Hernández Baumgarten ◽  
Pablo Correa Girón † ◽  
Oscar Torres Ángeles ◽  
...  
Keyword(s):  
Reference Strain ◽  
Clinical Signs ◽  
Classical Swine Fever ◽  
Fever Virus ◽  
Direct Immunofluorescence ◽  
Biometric Analysis ◽  
Treatment Groups ◽  
Group A ◽  
Group B ◽  
Group D

The study was to determine the presence of Classical Swine Fever virus (CSFv), in the meat of vaccinated pigs with the PAV-250 strain and then challenged using the same strain. Five treatment groups were established (each with four pigs). Group A: Pigs thatwere fed with processed hams from negative animals; Group B: Pigs that were fed with processed hams from commercial pigs inoculated with the ALD (reference strain) (titre of 104.0/ml); Group C: Pigs fed with processed hams from pigs infected with the virulent ALD strain (titre of 102.5/ml); Group D: Pigs fed with processed hams from pigs vaccinated with the PAV-250 strain and challenged with the ALD strain (titre of 101.1/ml); and Group E: Pigs fed with processed hams from pigs vaccinated with two doses of the PAV-250 strain and challenged with the ALD strain (negative). Blood samples were taken at d 1, 5, 10, 15 and 20 for biometric analysis. Groups B, C and D manifested clinical signs of CSFv: 40 °C temperature, anorexia, paralysis, vomiting, diarrhea, tremor, hirsute hair and cyanosis. Pigs were slaughtered and necropsies performed to identify lesions in tissues. Results of direct immunofluorescence testing of tissues were positive and the virus was recovered. Under these study conditions, it was found that CSFv resisted the cooking method at 68 °C for 40 min in hams from unvaccinated pigs, and that the virus was able to transmit the disease to healthy unvaccinated pigs, whereas the hams from the vaccinated animals did not transmit the virus.

scholarly journals The Bone Buttress Theory: The Effect of the Mechanical Loading of Bone on the Osseointegration of Dental Implants

Biology ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 12
Author(s):  
David Chavarri-Prado ◽  
Aritza Brizuela-Velasco ◽  
Ángel Álvarez-Arenal ◽  
Markel Dieguez-Pereira ◽  
Esteban Pérez-Pevida ◽  
...  
Keyword(s):  
Dental Implants ◽  
Mechanical Loading ◽  
Bone Growth ◽  
Bone Matrix ◽  
Test Group ◽  
Control Group ◽  
Group A ◽  
Bone To Implant Contact ◽  
The Stability ◽  
Group B

Objectives: To determine the effect of mechanical loading of bone on the stability and histomorphometric variables of the osseointegration of dental implants using an experimental test in an animal model. Materials and Methods: A total of 4 human implants were placed in both tibiae of 10 New Zealand rabbits (n = 40). A 6-week osseointegration was considered, and the rabbits were randomly assigned to two groups: Group A (Test group) included 5 rabbits that ran on a treadmill for 20 min daily during the osseointegration period; Group B (Controls) included the other 5 that were housed conventionally. The monitored variables were related to the primary and secondary stability of the dental implants (implant stability quotient—ISQ), vertical bone growth, bone to implant contact (BIC), area of regenerated bone and the percentage of immature matrix. Results: The results of the study show a greater vertical bone growth (Group A 1.26 ± 0.48 mm, Group B 0.32 ± 0.47 mm, p < 0.001), higher ISQ values (Group A 11.25 ± 6.10 ISQ, 15.73%; Group B 5.80 ± 5.97 ISQ, 7.99%, p = 0.006) and a higher BIC (Group A 19.37%, Group B 23.60%, p = 0.0058) for implants in the test group, with statistically significant differences. A higher percentage of immature bone matrix was observed for implants in the control group (20.68 ± 9.53) than those in the test group (15.38 ± 8.84) (p = 0.108). A larger area of regenerated bone was also observed for the test implants (Group A 280.50 ± 125.40 mm2, Group B 228.00 ± 141.40 mm2), but it was not statistically significant (p = 0.121). Conclusions: The mechanical loading of bone improves the stability and the histomorphometric variables of the osseointegration of dental implants.

Training-induced alterations of the in vivo force-velocity relationship of human muscle

1981 ◽  
Vol 51 (3) ◽  
pp. 750-754 ◽  
Author(s):  
V. J. Caiozzo ◽  
J. J. Perrine ◽  
V. R. Edgerton
Keyword(s):  
Training Group ◽  
Knee Extension ◽  
Knee Extensors ◽  
Velocity Relationship ◽  
Slow Velocity ◽  
Group A ◽  
Force Velocity ◽  
Group B ◽  
Relationship Of

Seventeen male and female subjects (ages 20–38 yr) were tested pre- and posttraining for maximal knee extension torque at seven specific velocities (0, 0.84, 1.68, 2.51, 3.35, 4.19, and 5.03 rad . s-1) with an isokinetic dynamometer. Maximal knee extension torques were recorded at a specific joint angle (0.52 rad below the horizontal plane) for all test speeds. Subjects were randomly assigned to one of three experimental groups: group A, control, n = 7; group B, training at 1.68 rad . s-1, n = 5; or group C, training at 4.19 rad . s-1, n = 5. Subjects trained the knee extensors by performing two sets of 10 single maximal voluntary efforts three times a week for 4 wk. Before training, each training group exhibited a leveling-off of muscular tension in the slow velocity-high force region of the in vivo force-velocity relationship. Training at 1.68 rad . s-1 resulted in significant (P less than 0.05) improvements at all velocities except for 5.03 rad . s-1 and markedly affected the leveling-off in the slow velocity-high force region. Training at 4.19 rad . s-1 did not affect the leveling-off phenomenon but brought about significant improvements (P less than 0.05) at velocities of 2.51, 3.35, and 4.19 rad . s-1. The changes seen in the leveling-off phenomenon suggest that training at 1.68 rad . s-1 might have brought about an enhancement of motoneuron activation.

scholarly journals Photopolymerizable Injectable Cartilage Mimetic Hydrogel for the Treatment of Focal Chondral Lesions: A Proof of Concept Study in a Rabbit Animal Model

2018 ◽  
Vol 47 (1) ◽  
pp. 212-221 ◽  
Author(s):  
Cecilia Pascual-Garrido ◽  
Elizabeth A. Aisenbrey ◽  
Francisco Rodriguez-Fontan ◽  
Karin A. Payne ◽  
Stephanie J. Bryant ◽  
...  
Keyword(s):  
Animal Model ◽  
Chondrogenic Differentiation ◽  
Osteochondral Lesions ◽  
Chondral Defect ◽  
Group A ◽  
Group B ◽  
Safranin O

Background: In this study, we investigate the in vitro and in vivo chondrogenic capacity of a novel photopolymerizable cartilage mimetic hydrogel, enhanced with extracellular matrix analogs, for cartilage regeneration. Purpose: To (1) determine whether mesenchymal stem cells (MSCs) embedded in a novel cartilage mimetic hydrogel support in vitro chondrogenesis, (2) demonstrate that the proposed hydrogel can be delivered in situ in a critical chondral defect in a rabbit model, and (3) determine whether the hydrogel with or without MSCs supports in vivo chondrogenesis in a critical chondral defect. Study Design: Controlled laboratory study. Methods: Rabbit bone marrow–derived MSCs were isolated, expanded, encapsulated in the hydrogel, and cultured in chondrogenic differentiation medium for 9 weeks. Compressive modulus was evaluated at day 1 and at weeks 3, 6, and 9. Chondrogenic differentiation was investigated via quantitative polymerase reaction, safranin-O staining, and immunofluorescence. In vivo, a 3 mm–wide × 2-mm-deep chondral defect was created bilaterally on the knee trochlea of 10 rabbits. Each animal had 1 defect randomly assigned to be treated with hydrogel with or without MSCs, and the contralateral knee was left untreated. Hence, each rabbit served as its own matched control. Three groups were established: group A, hydrogel (n = 5); group B, hydrogel with MSCs (n = 5); and group C, control (n = 10). Repair tissue was evaluated at 6 months after intervention. Results: In vitro, chondrogenesis and the degradable behavior of the hydrogel by MSCs were confirmed. In vivo, the hydrogel could be delivered intraoperatively in a sterile manner. Overall, the hydrogel group had the highest scores on the modified O’Driscoll scoring system (group A, 17.4 ± 4.7; group B, 13 ± 3; group C, 16.7 ± 2.9) ( P = .11) and showed higher safranin-O staining (group A, 49.4% ± 20%; group B, 25.8% ± 16.4%; group C, 36.9% ± 25.2%) ( P = .27), although significance was not detected for either parameter. Conclusion: This study provides the first evidence of the ability to photopolymerize this novel hydrogel in situ and assess its ability to provide chondrogenic cues for cartilage repair in a small animal model. In vitro chondrogenesis was evident when MSCs were encapsulated in the hydrogel. Clinical Relevance: Cartilage mimetic hydrogel may offer a tissue engineering approach for the treatment of osteochondral lesions.

scholarly journals RADIOLOGICAL STUDY OF MEGACOLON IN TRYPANOSOMA CRUZI INFECTED RATS

2018 ◽  
Vol 31 (1) ◽  
Author(s):  
Carlos Edmundo Rodrigues FONTES ◽  
Ana Paula de ABREU ◽  
Aretuza Zaupa GASPARIM
Keyword(s):  
Trypanosoma Cruzi ◽  
Wistar Rats ◽  
In Vivo Studies ◽  
Proposed Model ◽  
Male Wistar Rats ◽  
Group A ◽  
Time Of Infection ◽  
Group B ◽  
Digital Caliper

ABSTRACT Background: Researches on Chagas disease still use several animals and rats, due to size and susceptibility were preferred by many authors. Aim: To develop an experimental model of megacolon in rats inoculated with the strain Y of Trypanosoma cruzi. Methods: Thirty male Wistar rats were distributed in three groups inoculated with different inoculants: Group A: 600000, Group B: 1000000 and Group C: 1500000 blood trypomastigotes of T. cruzi. Animals were sedated intramuscularly at zero inoculation time (T0) and 60 days after inoculation (T60), to perform the barium enema in order to evaluate the dilatation of the different segments of colon in a comparative study of the measurements obtained, using a digital caliper. Evidence of infection was performed by blood smear collected from the animal’s tail 18 days after inoculation with observation of blood forms. Results: Comparing the intestinal diameter of the inoculated animals with 60,0000 trypomastigotes in the T0 of infection with T60 days after the inoculation, significant dilatation was observed between the proximal, medial and distal segments (p<0.01), indicating the establishment of the megacolon model. In addition, comparing intestinal diameter between the different segments, with in the T0 of infection and the T60 after inoculation, significant alterations were observed (p<0.05). Conclusion: The proposed model was possible for in vivo studies of alterations due to infection by T. cruzi and functional alterations of the colon. In addition, the changes manifested in the colon are not directly proportional to the size of the inoculum, but to the time of infection that the animals were submitted, since the animals inoculated with 60,0000 blood forms were the ones which presented the most significant alterations.

Treatment of bone metastases with dichloromethylene bisphosphonate.

1992 ◽  
Vol 10 (4) ◽  
pp. 591-598 ◽  
Author(s):  
G Francini ◽  
S Gonnelli ◽  
R Petrioli ◽  
F Conti ◽  
P Paffetti ◽  
...  
Keyword(s):  
Bone Metastases ◽  
Serum Alkaline Phosphatase ◽  
Urinary Calcium ◽  
Bone Lesions ◽  
Osteolytic Lesions ◽  
Concurrent Use ◽  
Pathologic Fractures ◽  
Group A ◽  
Group B

PURPOSE The study was undertaken to evaluate the effects of dichloromethylene bisphosphonate (Cl2MDP) on osteolytic and osteoblastic bone lesions from a variety of tumoral primary sites and to investigate the in vivo mechanism underlying the action of this drug. PATIENTS AND METHODS Seventy-six patients participated in the current study: 59 had predominantly osteolytic lesions and 17 osteoblastic metastases. Sixteen patients had hypercalcemia. All of the patients received 300 mg of Cl2MDP intravenously (IV) for 7 days and then 200 mg of Cl2MDP intramuscularly (IM) for 14 days. Biochemical parameters were measured in the patients before the start of treatment and 3, 7, 14, and 21 days after beginning treatment. After the withdrawal of parenteral Cl2MDP, 59 patients with predominantly osteolytic lesions were then randomized to receive chemotherapy alone (group A, 29 cases) or chemotherapy plus Cl2MDP given at an oral dose of 1,200 mg/d (group B, 30 cases). RESULTS Serum calcium (Ca), urinary calcium (UCa) phosphate (UPO4), and hydroxyproline (HOP) excretion levels significantly decreased in all patients, whereas no significant changes occurred in serum alkaline phosphatase (AlkPh) and bone Gla-protein (BGP) levels. In 56 patients with painful bone lesions, a progressive analgesic effect was observed mainly between day 7 and day 14. In patients with predominantly osteoblastic metastases, the Cl2MDP treatment led to a more evident hypocalcemia and an increase in both AlkPh and BGP. However, in the majority of these patients the hypocalcemia was corrected by the concurrent use of effective cytotoxic treatments capable of reducing osteoblast stimulation. During 6 months of follow-up, two pathologic fractures occurred in patients of group A, and none occurred in patients of group B. CONCLUSIONS We conclude that Cl2MDP was effective in patients presenting bone metastases with and without hypercalcemia. Care should be taken particularly in those patients with mixed metastases when the sclerotic component is predominant, as the drug may enhance the possibility of hypocalcemia, which is generally corrected by effective cytotoxic drugs. Therefore, Cl2MDP can be considered a valuable support in the treatment of bone metastases.

scholarly journals Magnetic resonance imaging and computed tomography of equine cheek teeth and adjacent structures: comparative study of image quality in horses in vivo, post-mortem and frozen-thawed

2019 ◽  
Vol 61 (1) ◽  
Author(s):  
Christin Röttiger ◽  
Maren Hellige ◽  
Bernhard Ohnesorge ◽  
Astrid Bienert-Zeit
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Post Mortem ◽  
Mr Images ◽  
Adjacent Structures ◽  
Group A ◽  
Group B ◽  
The Impact ◽  
Ct And Mri

Abstract Background The use of cadavers for radiology research methodologies involving subjective image quality evaluation of anatomical criteria is well-documented. The purpose of this method comparison study was to evaluate the image quality of dental and adjacent structures in computed tomography (CT) and high-field (3 T) magnetic resonance (MR) images in cadaveric heads, based on an objective four-point rating scale. Whilst CT is a well-established technique, MR imaging (MRI) is rarely used for equine dental diagnostics. The use of a grading system in this study allowed an objective assessment of CT and MRI advantages in portraying equine cheek teeth. As imaging is commonly performed with cadaveric or frozen and thawed heads for dental research investigations, the second objective was to quantify the impact of the specimens’ conditions (in vivo, post-mortem, frozen-thawed) on the image quality in CT and MRI. Results The CT and MR images of nine horses, focused on the maxillary premolar 08s and molar 09s, were acquired post-mortem (Group A). Three observers scored the dental and adjacent tissues. Results showed that MR sequences gave an excellent depiction of endo- and periodontal structures, whereas CT produced high-quality images of the hard tooth and bony tissues. Additional CT and MRI was performed in vivo (Group B) and frozen-thawed (Group C) in three of these nine horses to specify the condition of the best specimens for further research. Assessing the impact of the specimens’ conditions on image quality, specific soft tissues of the maxillary 08s and 09s including adjacent structures (pulps, mucosa of the maxillary sinuses, periodontal ligament, soft tissue inside the infraorbital canal) were graded in group B and C and analysed for significant differences within CT and MR modalities in comparison to group A. Results showed that MRI scores in vivo were superior to the post-mortem and frozen-thawed condition. Conclusions On comparing the imaging performance of CT and MRI, both techniques show a huge potential for application in equine dentistry. Further studies are needed to assess the clinical suitability of MRI. For further research investigations it must be considered, that the best MR image quality is provided in live horses.

Assessment of the Correlation Between Insertion Torque and Resonance Frequency Analysis of Implants Placed in Bone Tissue of Different Densities

2014 ◽  
Vol 40 (3) ◽  
pp. 259-262 ◽  
Author(s):  
Luiz Carlos Magno Filho ◽  
Fabiano Ribeiro Cirano ◽  
Fernando Hayashi ◽  
Hsu Shao Feng ◽  
Alexandre Conte ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Dental Implants ◽  
Frequency Analysis ◽  
Pearson Correlation ◽  
T Test ◽  
Insertion Torque ◽  
Type I ◽  
Resonance Frequency Analysis ◽  
Group A ◽  
Group B

The primary stability of dental implants is fundamental for osseointegration. Therefore, this study aimed to assess the correlation between insertion torque (IT) and resonance frequency analysis (RFA) of implants placed in mandibles and maxillas of different bone densities. Eighty dental implants were placed in maxillas and mandibles, and IT and the implant stability quotient (ISQ) were measured at the time of implant insertion. Bone density was assessed subjectively by the Lekholm and Zarb index. The type I and II densities were grouped together (group A)as were the type III and IV densities (group B). The IT in group A was higher (Student t test, P = .0013) than in group B (46.27 ± 18.51 Ncm, 33.62 ± 14.74 Ncm, respectively). The implants placed in group A showed higher ISQ (Student t test, P = .0004) than those placed in group B (70.09 ± 7.50, 63.66 ± 8.00, respectively). A significant correlation between IT and the ISQ value was observed for group A (Pearson correlation test; r = 0.35; P = .0213) and for group B (r = 0.37; P = .0224). Within the limitations of this study, it was possible to conclude that there is a correlation between IT and RFA of implants placed in mandibles and maxillas of different bone densities.

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