Effect of Systemic Intermittent Administration of Human Parathyroid Hormone (RHPTH[1–34]) on the Resistance to Reverse Torque in Rabbit Tibiae

2008 ◽  
Vol 34 (6) ◽  
pp. 298-302 ◽  
Author(s):  
Marcelo Soeiro Corsini ◽  
Fátima N. Faraco ◽  
Alessandra A. Pereira Castro ◽  
Tatiana Onuma ◽  
Wilson R. Sendyk ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Test Group ◽  
Control Group ◽  
Human Parathyroid Hormone ◽  
Removal Torque ◽  
Intermittent Administration ◽  
Reverse Torque ◽  
Implant Placement ◽  
Torque Values ◽  
The Right

Abstract The aim of this study was to evaluate the effect of intermittent administration of human parathyroid hormone [rhPTH (1–34)] on the removal torque of implants placed in rabbit tibiae. Twenty male New Zealand rabbits were submitted to implant surgery. Each animal received one machined screw-type implant (3.75 mm diameter × 8 mm length) in the proximal metaphysis of the right tibia. The rabbits were then divided into 2 groups: the test group (n = 10) received 6 μg/kg of rhPTH (1–34) subcutaneously in the dorsal region 3 days a week, and the control group (n = 10) received placebo. Removal torque was performed at 28 and 56 days after implant placement for both groups. The mean removal torque values at 28 days were 37.0 ± 4.36 Ncm and 47.4 ± 6.77 Ncm for control and test groups respectively (P < .05). At 56 days the reverse torque was 45.8 ± 3.96 Ncm for the control group and 55.8 ± 2.86 Ncm for the test group, indicating that the removal torque was significantly higher in the test groups (P < .05). These results demonstrated that intermittent treatment with rhPTH (1–34) enhanced the removal torque of implants in rabbit tibiae.

scholarly journals Torque Analysis of Self-drilling Mini-screws placed with and without a Pilot Drill: A Canine Study

2014 ◽  
Vol 4 (2) ◽  
pp. 77-86
Author(s):  
Eric S Solomon ◽  
David G Kerns ◽  
William W Hallmon ◽  
Daniela A Zambon-Fagundes
Keyword(s):  
Success Rate ◽  
Test Group ◽  
Control Group ◽  
Success Rates ◽  
Removal Torque ◽  
Implant Placement ◽  
Significant Difference ◽  
Torque Analysis ◽  
The Mean ◽  
Canine Study

ABSTRACT Purpose The use of temporary anchorage devices (TADs), such as mini-screws, palatal implants and mini-plates, has become a popular treatment option in orthodontics. The objectives of this study were: (1) to compare the success rates of self-drilling mini-screws placed with or without use of a pilot drill, (2) to evaluate the implant placement torque (IPT) of self-drilling miniscrews and (3) to measure the removal torque of self-drilling mini-screws. Materials and methods Six American foxhounds served as subjects in this study. Three OsteoMed self-drilling mini-screws (1.6 mm diameter and 8 mm length) were planned to be placed in each side of the mandible between the roots of the teeth canine/premolar 1 (PM1), PM2/PM3 and PM3/PM4. The sites were allocated randomly in: (1) control group—mini-screws placed with pilot drill and (2) test group—mini-screws placed without pilot drill (self-drilling). The implant placement torque (IPT) and the number of turns performed by the mini-screws during placement were measured. After a healing period of 6 weeks, the mini-screws were removed, and the removal torque was measured. Results A total of 33 mini-screws were placed in six animals. After 6 weeks, the success rate for the control and test groups were 46.7 and 80% respectively (difference not statistically significant). There was no statistically significant difference in the terminal mean IPT values and the mean number of turns for failed and successful mini-screws. The difference between the mean IPT values at the 3rd turn during mini-screw placement in the successful and failed mini-screws (5.56 and 14.03 Ncm respectively) was statistically significant (p < 0.01). Conclusion There was no statistically significant difference in the success rate between self-drilling mini-screws that did or did not have osteotomies (46 vs 80% respectively). However, the IPT at the third revolution for successful mini-screws averaged 5.56 Ncm (p < 0.01). How to cite this article Zambon-Fagundes DA, Kerns DG, Hallmon WW, Solomon ES. Torque Analysis of Self-Drilling Mini-screws placed with and without a Pilot Drill: A Canine Study. J Contemp Dent 2014;4(2):77-86.

Reverse torque values of abutment screws after dynamic loading: The effects of sealant agents and the taper of conical connections

2020 ◽  
Author(s):  
Arda Ozdiler ◽  
suleyman dayan ◽  
Burc Gencel ◽  
Gulbahar Isık-Ozkol
Keyword(s):  
Dynamic Loading ◽  
Antibacterial Agent ◽  
In Vitro Study ◽  
Control Group ◽  
Silicone Sealant ◽  
Reverse Torque ◽  
The Stability ◽  
Torque Values ◽  
Chlorhexidine Gel

This in vitro study evaluated the influence of taper angles on the internal conical connections of implant systems and of the application of chlorhexidine gel as an antibacterial agent or a polyvinyl siloxane (PVS) sealant on the reverse torque values of abutment screws after dynamic loading. The current study tested four implant systems with different taper angles (5.4°, 12°, 45°, and 60°). Specimens were divided into three groups: control (neither chlorhexidine gel filled nor silicone sealed), 2% chlorhexidine gel-filled or silicone-sealed group, and group subjected to a dynamic load of 50 N at 1 Hz for 500,000 cycles prior to reverse torque measurements. Quantitative positive correlation was observed between the taper angle degree and the percentage of tightening torque loss. However, this correlation was significant only for the 60° connection groups except in the group in which a sealant was applied ( p = 0.013 for the control group, p = 0.007 for the chlorhexidine group). Percentages of decrease in the torque values of the specimens with silicone sealant application were significantly higher compared with both the control and chlorhexidine groups ( p = 0.001, p = 0.002, p = 0.001, and p = 0.002, respectively, according to the increasing taper angles); the percentage of decrease in torque values due to chlorhexidine application was statistically insignificant when compared with the control group. The application of gel-form chlorhexidine as an antibacterial agent does not significantly affect the stability of the implant–abutment connection under dynamic loads. PVS sealants may cause screw loosening under functional loads.

Short-term Changes After Corticosteroid Injections Into the Normal Tendons of Rabbits: A Controlled Randomized Study

2019 ◽  
Vol 47 (3) ◽  
pp. 721-728 ◽  
Author(s):  
Kandir Genesio Innocenti Dinhane ◽  
Alexandre Leme Godoy-Santos ◽  
Alexandre Todorovic Fabro ◽  
Maria Regina Moretto ◽  
Igor Deprá ◽  
...  
Keyword(s):  
Single Injection ◽  
Corticosteroid Injection ◽  
Healing Process ◽  
Test Group ◽  
Control Group ◽  
Placebo Control ◽  
Short Term ◽  
Calcaneal Tendon ◽  
The Right ◽  
Corticosteroid Injections

Background: Corticosteroid injections in or around tendons for the treatment of athletic injuries are a common practice among orthopaedic surgeons and are apparently efficacious in the short term, although controversies persist related to local complications. Purpose: This study evaluated short-term (48 hours) biomechanical, biochemical, and histological alterations after a single injection of betamethasone into the normal tendons of rabbits. Study Design: Controlled laboratory study. Methods: A total of 72 New Zealand White rabbits were randomly divided into 2 groups: the test group—in which 36 animals underwent 1 intratendinous injection of betamethasone (1.4 mg / 0.2 mL) in the right calcaneal tendon; the control group—in which the right calcaneal tendon of 36 animals was injected with saline (placebo control group) and the left calcaneal tendon was left untreated for normal standards (normal control). Forty-eight hours later, animals were euthanized and tendons were harvested. Metalloproteinase (MMP1 and MMP2) and interleukin (IL1 and IL6) expression levels, biomechanical resistance (load × elongation parameters), and histomorphometry (hematoxylin and eosin and picrosirius red stains for collagen fibers, tenocytes, and inflammatory cells) were analyzed in the tendons. Results: The test group had a significant reduction in MMP2 expression as compared with the control groups ( P = .027). Regarding the other parameters, there were no additional significant differences between the groups. Conclusion: A single injection of corticosteroid into normal calcaneal tendons did not trigger acute local morphological, structural, or biomechanical injuries at 48 hours, but it did promote a significant decrease in MMP2 levels. Additional studies are needed with increased duration of follow-up, various doses, and multiple injections and in tendinopathic models. Clinical Relevance: Some previous studies demonstrated early structural changes in tendons after a single corticosteroid injection, which was not corroborated by the present study. Metalloproteinase decrease is usually associated with a reduction in collagen degradation, which would be protective for the healing process. More studies are necessary to confirm the possible beneficial effect of these results in the long term and for tendinopathies.

Effect of intermittent administration of human parathyroid hormone(1–34) on bone mass in orchidectomized dogs

1992 ◽  
Vol 17 ◽  
pp. 128
Author(s):  
M. Hori ◽  
S. Fukuda ◽  
T. Uzawa ◽  
Y. Isogai ◽  
H.E. Takahashi ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Bone Mass ◽  
Human Parathyroid Hormone ◽  
Intermittent Administration

scholarly journals Assessment of Marginal Bone Loss around Platform-Matched and Platform-Switched Implants - A Prospective Study

2016 ◽  
Vol 27 (6) ◽  
pp. 712-716 ◽  
Author(s):  
Newton Sesma ◽  
Carlos Garaicoa-Pazmino ◽  
Piero R. Zanardi ◽  
Eliseo P. Chun ◽  
Dalva Cruz Laganá
Keyword(s):  
Bone Loss ◽  
Positive Impact ◽  
Test Group ◽  
Control Group ◽  
Bone Modeling ◽  
Radiographic Assessment ◽  
Marginal Bone Loss ◽  
Implant Placement ◽  
Platform Switching ◽  
Implant Loading

Abstract The aim of the present study was to perform a software-assisted radiographic assessment of the effect of platform-switching on marginal bone loss (MBL) around dental implants. Forty patients requiring a dental implant in non-grafted partially edentulous mandibles were enrolled and categorized into implants receiving a platform-matched abutment (control group) or implants with a platform-switched abutment (test group). Standardized digital periapical radiographs were taken at the time of implant placement (T0), at implant loading (T1) and 1-year after functional loading (T2). Software-assisted radiographic assessment of the MBL horizontal, vertical and area changes was performed and compared between time intervals (T1-T0, T2-T1 and T2-T0). Mean radiographic horizontal MBL (hMBL) and vertical MBL (vMBL) from implant placement to 1-year after implant loading (T2-T0) were significantly increased around platform-matched when compared to platform-switched abutments (1.04 mm vs 0.84 mm, p<0.05) and (0.99 mm vs 0.82 mm, p<0.05), respectively. Additionally, bone loss area (BLa) was greater (0.77 mm2 vs 0.63 mm2; p<0.05) for platform-matched compared to platform-switched abutments. Platform-switching has a positive impact upon the amount of bone modeling after loading implants with internal hexagon connection.

Comparison of Delayed Implant Placement vs Immediate Implant Placement Using Resonance Frequency Analysis: A Pilot Study on Rabbits

2011 ◽  
Vol 37 (5) ◽  
pp. 543-548 ◽  
Author(s):  
Ashish T. Kunnekel ◽  
Mohit T. Dudani ◽  
Chandrasekharan K. Nair ◽  
E. M. Naidu ◽  
G. Sivagami
Keyword(s):  
Resonance Frequency ◽  
Frequency Analysis ◽  
Test Group ◽  
Placement Test ◽  
Control Group ◽  
Resonance Frequency Analysis ◽  
Implant Placement ◽  
Immediate Placement ◽  
Immediate Implant ◽  
Delayed Implant Placement

Ten identical implants were equally divided into 2 groups. In the immediate placement (control) group, implants were placed immediately following osteotomy preparation, and in the delayed placement (test) group, implants were placed 2 weeks following osteotomy preparation, in rabbit femurs. Implant stability quotient values for both groups were measured using resonance frequency analysis immediately following placement and at day 40. Results were statistically analyzed and indicate that delayed placement of implants leads to faster rates of osseointegration.

scholarly journals TL 18099 - Short-term changes after corticosteroid injections into the normal tendons of rabbits

2019 ◽  
Vol 13 (Supl 1) ◽  
pp. 82S
Author(s):  
Alexandre Leme Godoy-Santos ◽  
Kandir Genesio Innocenti Dinhane ◽  
Alexandre Todorovic Fabro ◽  
Maria Regina Moretto ◽  
Igor Depra ◽  
...  
Keyword(s):  
Single Injection ◽  
Test Group ◽  
Inflammatory Cells ◽  
Control Group ◽  
Placebo Control ◽  
Short Term ◽  
Calcaneal Tendon ◽  
Hematoxylin And Eosin ◽  
The Right ◽  
Corticosteroid Injections

Introduction: Corticosteroid injections in or around tendons for the treatment of athletic injuries are a common practice among orthopedic surgeons and are apparently efficacious in the short term, although controversies persist related to local complications. Objective: This study evaluated short-term (48 hours) biomechanical, biochemical, and histological alterations after a single injection of betamethasone into the normal tendons of rabbits. Methods: A total of 72 New Zealand White rabbits were randomly divided into 2 groups: the test group - in which 36 animals underwent 1 intratendinous injection of betamethasone (1.4 mg / 0.2 mL) in the right calcaneal tendon; the control group - in which the right calcaneal tendon of 36 animals was injected with saline (placebo control group) and the left calcaneal tendon was left untreated for normal standards (normal control). Forty-eight hours later, the animals were euthanized and the tendons harvested. Metalloproteinase (MMP1 and MMP2) and interleukin (IL1 and IL6) expression levels, biomechanical resistance (load 3 elongation parameters), and histomorphometry (hematoxylin and eosin and picrosirius red stains for collagen fibers, tenocytes, and inflammatory cells) were analyzed in the tendons. Results: The test group showed a significant reduction in MMP2 expression compared with the control groups (P = .027). Regarding the other parameters, there were no additional significant differences between the groups. Conclusion: A single injection of corticosteroid into normal calcaneal tendons did not trigger acute local morphological, structural, or biomechanical injuries at 48 hours, but it did promote a significant decrease in MMP2 levels. Additional studies are needed with increased follow-up durations, various doses, and multiple injections and in tendinopathic models.

scholarly journals A new inertial navigation system for guiding implant placement. An in-vitro proof-of-concept study

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0255481
Author(s):  
G. Esteve-Pardo ◽  
L. Esteve-Colomina ◽  
E. Fernández
Keyword(s):  
Dental Implant ◽  
Navigation System ◽  
Inertial Navigation System ◽  
Computer Navigation ◽  
Inertial Navigation ◽  
Test Group ◽  
Control Group ◽  
Angular Deviation ◽  
Processing Unit ◽  
Implant Placement

The aim of this study was to assess the potential use of a new advanced inertial navigation system for guiding dental implant placement and to compare this approach with standard stereolithographic template guiding. A movement processing unit with a 9-axis absolute orientation sensor was adapted to a surgical handpiece and wired to a computer navigation interface. Sixty implants were placed by 10 operators in 20 jaw models. The 30 implants of the test group were placed in 10 models guided by the new inertial navigation prototype. The 30 implants of the control group were placed in another 10 models using a CAD-CAM template. Both groups were subdivided into experienced and non-experienced operators. Pre- and postoperative computer tomography images were obtained and matched to compare the planned and final implant positions. Four deviation parameters (global, angular, depth, and lateral deviation) were defined and calculated. The primary outcome was the angular deviation between the standard stereolithographic approach and the new inertial navigation system. Results showed no significant differences between both groups, suggesting that surgical navigation based on inertial measurement units (IMUs) could potentially be useful for guiding dental implant placement. However, more studies are still needed to translate this new approach into clinical practice.

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