scholarly journals Effect of Wet Field on the DE Torque Values of Abutment Screws

2020 ◽  
Vol 11 (SPL3) ◽  
pp. 843-846
Author(s):  
Pravinya Sam ◽  
Suresh Venugopalan ◽  
Dhanraj Ganapathy
Keyword(s):  
Artificial Saliva ◽  
Blood Clot ◽  
Screw Loosening ◽  
Screw Hole ◽  
Significant Difference ◽  
Implant Abutment ◽  
Torque Values ◽  
Soft Tissue Inflammation ◽  
Plaster Models ◽  
Abutment Screw

Screw loosening is amongst the most prevalent mechanical problems in dental implant prosthetics. Clinicians will know if the reverse Detorque values are compromised by contamination of the implant abutment screw hole either by blood , saliva or saline. Research have shown that the drying of the implant cavity may decrease the preload value when the abutment screw is closed and thereafter increase the likelihood of abutment screw loosening. Mobility of the prosthesis, or screw fracture and increase the risk of peri-implant soft-tissue inflammation. This study aims to assess and compare the effect of wet and dry fields while torqueing the abutment screws on the DE torque values. 40 Nobel bio care implant analogues mounted in plaster models were used in this study. The samples were divided into four groups dry abutment screws, artificial saliva, blood and normal saline. All the abutment screws were tightened till 20 Ncm and left aside for 15 minutes. After 15 minutes the abutment screw were DE torqued, and the DE torque values were noted for tall the groups. When analysed using paired sample t-test there was no significant difference with artificial saliva (p=0.269). There was statistical difference with blood (p=0.00) and with saline (p=0.00). Based on this study, the presence of saliva decreases the DE torque values of the abutment screws, whereas Blood and saline increase the DE torque values of the abutment screws. The presence of blood clot might be the reason for the increase in DE torque values which might decrease once the clot disintegrates. Clinicians should prevent contamination of the screw hole by blood and saliva; if contamination arises, sanitation of the infected screw and also the screw hole until final tightening is advised.

scholarly journals In Vitro Evaluation of Manual Torque Values Applied to Implant-Abutment Complex by Different Clinicians and Abutment Screw Loosening

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Onur Dincer Kose ◽  
Burcin Karataslı ◽  
Sabit Demircan ◽  
Taha Emre Kose ◽  
Erhan Cene ◽  
...  
Keyword(s):  
Dynamic Loading ◽  
Optical Microscope ◽  
Control Group ◽  
Screw Loosening ◽  
Loading Test ◽  
Torque Wrench ◽  
Implant Abutment ◽  
Torque Values ◽  
Abutment Screw

Preload is applied to screws manually or using a torque wrench in dental implant systems, and the preload applied must be appropriate for the purpose. The aim of this study was to assess screw loosening and bending/torsional moments applied by clinicians of various specialties following application of manual tightening torque to combinations of implants and abutments. Ten-millimeter implants of 3.7 and 4.1 mm diameters and standard or solid abutments were used. Each group contained five implant-abutment combinations. The control and experimental groups comprised 20 and 160 specimens, respectively. Implants in the experimental group were tightened by dentists of different specialties. Torsional and bending moments during tightening were measured using a strain gauge. Control group and implants with preload values close to the ideal preload were subjected to a dynamic loading test at 150 N, 15 Hz, and 85,000 cycles. The implants that deformed in this test were examined using an optical microscope to assess deformities. Manual tightening did not yield the manufacturer-recommended preload values. Dynamic loading testing suggested early screw loosening/fracture in samples with insufficient preload.

scholarly journals Comparison of the Effect of Four Different Abutment Screw Torques on Screw Loosening in Single Implant-Supported Prosthesis after the Application of Mechanical Loading

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Behnaz Ebadian ◽  
Amirhossein Fathi ◽  
Saba Khodadad
Keyword(s):  
Mechanical Loading ◽  
Screw Loosening ◽  
Group 4 ◽  
Significant Difference ◽  
Torque Loss ◽  
Group 2 ◽  
Torque Values ◽  
Post Hoc ◽  
Single Implant ◽  
Abutment Screw

Background. The complications of implant-supported prostheses can be classified into mechanical and biological ones, one part of which is associated with screw loosening. This study was aimed to compare the effect of four different abutment screw torque techniques on screw loosening in single implant-supported prostheses following the application of mechanical loading. Materials and Methods. In this experimental study, a total of 40 implants in acrylic blocks (6 × 10 × 20 mm) were mounted perpendicular to the surface. They were then randomly divided into four groups: (1) torquing once with 30 Ncm, (2) torquing three times with 30 Ncm and 5-minute intervals, (3) torquing once with 30 Ncm, opening the screw, and retorquing with 30 Ncm, and (4) torquing once with 35 Ncm. The torque values were confirmed by using a digital torque meter. Then, the samples underwent a force (2 cps, 0.453–11.793 kg) for three hours before the measurement of detorque values. The screw loosening force (torque) was then measured and recorded. The obtained data were analyzed by SPSS (version 22) software using one-way ANOVA and Tukey post hoc test at a 5% error level. Results. The maximum mean detorque values of the abutment screws in single implant-supported prostheses were reported for groups 4 (27.8 ± 1.3), 1 (26.8 ± 1.3), and 3 (25.1 ± 1.3), and the minimum mean detorque value was found in group 2 (24.9 ± 1.2). Moreover, no significant difference was observed between groups 2 and 3 ( p > 0.05 ), but a significant difference was found between groups 1 and 3 and other groups ( p < 0.05 ). Conclusion. The increase in the torque value increased the torque loss. However, the detorque value in group 4 showed the least difference with the value recommended by the manufacturer (30 Ncm).

scholarly journals Evaluation of the Sealing Capability of the Internal Conical Connections of Implants with Titanium and Zirconia Abutments

2017 ◽  
Vol 18 (10) ◽  
pp. 915-922 ◽  
Author(s):  
Ilser Turkyilmaz ◽  
Damian L Black ◽  
Chol H Chong
Keyword(s):  
P Value ◽  
Colony Forming Units ◽  
Significant Difference ◽  
Implant Abutment ◽  
Level Of Significance ◽  
Torque Values ◽  
Post Hoc ◽  
Positive Controls ◽  
Abutment Screw

ABSTRACT Aim The purpose of this in vitro investigation was to evaluate the sealing capability of the conical implant–abutment interfaces under different abutment screw torque values using titanium and zirconia abutments with Morse taper designs. Materials and methods A total of 42 dental implants (n = 21 for titanium abutments and n = 21 for zirconia abutments) were inoculated internally with three bacteria. These assemblies were divided into four test groups (n = 10) based on screw fixation torques of 35 or 20 Ncm and placed in sterile broth; the remaining abutments were used as positive controls and torqued to 10 Ncm. Microleakage was quantified by enumerating the bacteria from the colony-forming units. An analysis of variance for the estimates of bacteria enumerated and microgaps was used with a post hoc analysis as indicated. A p-value of 0.05 was used as the level of significance. Results There was no statistically significant difference in microleakage among the four test groups; there were no significant effects of screw torque or abutment type on the bacteria enumerated. There was a significantly smaller mean microgap with the zirconia abutments. Conclusion The results of this study indicated no statistically significant difference in the sealing capabilities between titanium and zirconia abutments, having internal conical connections, after increasing the abutment screw torque. Clinical significance It is important for clinicians to follow the guidelines suggested by the implant companies to avoid biomechanical complications over time. How to cite this article Black DL, Turkyilmaz I, Lien W, Chong CH. Evaluation of the Sealing Capability of the Internal Conical Connections of Implants with Titanium and Zirconia Abutments. J Contemp Dent Pract 2017;18(10):915-922.

scholarly journals A Novel Technique Using Polytetrafluoroethylene Tape to Solve Screw Loosening Complication in Implant-Supported Single Crowns

2020 ◽  
Vol 18 (1) ◽  
pp. 125
Author(s):  
Luis F. Félix ◽  
Michell Medina ◽  
Cristina Gómez-Polo ◽  
Rubén Agustín-Panadero ◽  
Rocío Ortega ◽  
...  
Keyword(s):  
Control Group ◽  
Screw Loosening ◽  
Novel Technique ◽  
Reverse Torque ◽  
Titanium Screws ◽  
Implant Abutment ◽  
Torque Values ◽  
Single Crowns ◽  
Screw Group ◽  
Abutment Screw

This study aimed to analyze a novel technique to make screws with greater untightening resistance and to solve screw loosening in implant-supported single crowns. Thirty grade IV titanium straight abutments were screwed onto 30 external hex implants using grade IV titanium screws (30 Ncm). They were exposed to cyclic loading (300,000 cycles, 200 N). Samples were divided into 4 groups (15 samples per group): new screws (SCREW group) (control), reused screws (rSCREW group), new screws wrapped with polytetrafluoroethylene (PTFE) tape (PTFE group), and reused screws wrapped with PTFE tape (rPTFE group). Reverse torque values (RTVs) were recorded with a digitally calibrated implant motor. Mean RTVs observed were 14.46 N (±1.10 N) for the control group, 14.42 N (±1.22 N) for the rSCREW group, 19.97 N (±1.16 N) for the PTFE group, and 19.13 N (±2.38 N) for the rPTFE group. Statistically significant differences were found between RTVs of both groups employing screws without PTFE tape (SCREW and rSCREW groups) compared with those using screws wrapped with PTFE tape (PTFE and rPTFE) (p < 0.001). These results suggest that wrapping the implant–abutment screw with PTFE tape may effectively lower the risk of loosening and even constitute a solution when this complication occurs in implant single crowns.

scholarly journals The Evolution of External and Internal Implant–Abutment Connections: A Review

2012 ◽  
Vol 2 (2) ◽  
pp. 37
Author(s):  
D.R. Prithviraj ◽  
Ninad Muley ◽  
Vikas Gupta
Keyword(s):  
Native Speakers ◽  
Screw Loosening ◽  
Implant Abutment ◽  
Primary Determinant ◽  
Native Speakers Of English ◽  
Over Time ◽  
Abutment Screw

A study of the implant–abutment connection is of great importance because it is the primary determinant of the strength and stability of an implant-supported restoration, which, in turn, determines the restoration’s prosthetic stability. Traditionally, Brånemark’s external hexagon has been used, but significant complications, such as abutment screw loosening, rotational misfit at the implant–abutment interface, and microbial penetration have led to modification of the external hexagon and the development of internal implant–abutment connections. In this review, we describe various implant–abutment connections that have evolved over time from the traditional external hexagon.  How to cite this article: Alharissy M, Dayoub S. The Evolution of External and Internal Implant–Abutment Connections: A Review. Int Dent Res 2012;2:37-42. Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

scholarly journals An Indirect Method to Measure Abutment Screw Preload: A Pilot Study Based on Micro-CT Scanning

2015 ◽  
Vol 26 (6) ◽  
pp. 596-601 ◽  
Author(s):  
Carlos Eduardo E. Rezende ◽  
Jason Alan Griggs ◽  
Yuanyuan Duan ◽  
Amanda M. Mushashe ◽  
Gisele Maria Correr Nolasco ◽  
...  
Keyword(s):  
Ct Scanning ◽  
Measuring Method ◽  
Micro Ct ◽  
Ct Scanner ◽  
Removal Torque ◽  
Ct Technique ◽  
Original Length ◽  
Implant Abutment ◽  
Torque Values ◽  
Abutment Screw

This study aimed to measure the preload in different implant platform geometries based on micro-CT images. External hexagon (EH) implants and Morse Tapered (MT) implants (n=5) were used for the preload measurement. The abutment screws were scanned in micro-CT to obtain their virtual models, which were used to record their initial length. The abutments were screwed on the implant with a 20 Ncm torque and the set composed by implant, abutment screw and abutment were taken to the micro-CT scanner to obtain virtual slices of the specimens. These slices allowed the measurement of screw lengths after torque application and based on the screw elongation. Preload values were calculated using the Hooke's Law. The preloads of both groups were compared by independent t-test. Removal torque of each specimen was recorded. To evaluate the accuracy of the micro-CT technique, three rods with known lengths were scanned and the length of their virtual model was measured and compared with the original length. One rod was scanned four times to evaluate the measuring method variation. There was no difference between groups for preload (EH = 461.6 N and MT = 477.4 N), but the EH group showed higher removal torque values (13.8±4.7 against 8.2±3.6 Ncm for MT group). The micro-CT technique showed a variability of 0.053% and repeatability showed an error of 0.23 to 0.28%. Within the limitations of this study, there was no difference between external hexagon and Morse taper for preload. The method using micro-CT may be considered for preload calculation.

scholarly journals Effect of Mechanical Cycling on Screw Torque in External Hexagon Implants with and without Platform Switching

2015 ◽  
Vol 26 (3) ◽  
pp. 284-287 ◽  
Author(s):  
Bruno Andrade Cantharino de Carvalho ◽  
Eduardo Vedovatto ◽  
Paulo Sérgio Perri de Carvalho ◽  
José Vitor Quinelli Mazaro ◽  
Rosse Mary Falcón-Antenucci
Keyword(s):  
In Vitro Study ◽  
Screw Loosening ◽  
Removal Torque ◽  
Tukey Test ◽  
Reverse Torque ◽  
Mechanical Cycling ◽  
Significant Difference ◽  
Platform Switching ◽  
Abutment Screw

This in vitro study evaluated the effect of mechanical cycling on the torque of retaining screw in external hexagon implants with platform switching (PS), regular platform (RP) and wide platform (WP). A total of 30 specimens were equally divided into 3 groups: PS, PR and WP. Each specimen was prepared with implants: 3.75 x 10 mm for RP group and 5.0x10 mm for PS and WP groups and its respective abutment with 32 Ncm torque. All groups were subjected to 106 cycles with 100 N (corresponding to about 40 months of chewing). The results were obtained with the reverse torque of each specimen and data were evaluated using ANOVA and Tukey test (p<0.05). The PS group showed statistically significant difference in screw removal torque (30.06±5.42) compared with RP (23.75±2.76) and WP (21.32±3.53) (p<0.05) groups; the RP and WP groups showed no statistically significant difference between them. It was concluded that the PS group showed higher reverse torque value, suggesting lower susceptibility of the abutment screw loosening.

Influence of implant/abutment joint designs on abutment screw loosening in a dental implant system

2005 ◽  
Vol 75B (2) ◽  
pp. 457-463 ◽  
Author(s):  
Tsuyoshi Kitagawa ◽  
Yasuhiro Tanimoto ◽  
Misako Odaki ◽  
Kimiya Nemoto ◽  
Masahiro Aida
Keyword(s):  
Dental Implant ◽  
Screw Loosening ◽  
Implant Abutment ◽  
Implant System ◽  
Abutment Screw

Implant Abutment Screw Reverse Torque Values Before and After Plasma Cleaning

2013 ◽  
Vol 26 (4) ◽  
pp. 331-333 ◽  
Author(s):  
Costanza Micarelli ◽  
Luigi Canullo ◽  
Paolo Baldissara ◽  
Marco Clementini
Keyword(s):  
Plasma Cleaning ◽  
Reverse Torque ◽  
Implant Abutment ◽  
Before And After ◽  
Torque Values ◽  
Abutment Screw

The Effect of a Positioning Index on the Biomechanical Stability of Tapered Implant-Abutment Connections

2015 ◽  
Vol 41 (2) ◽  
pp. 139-143 ◽  
Author(s):  
Eduardo Aydos Villarinho ◽  
André Cervieri ◽  
Rosemary Sadami Arai Shinkai ◽  
Márcio Lima Grossi ◽  
Eduardo Rolim Teixeira
Keyword(s):  
Strain Gauges ◽  
Biomechanical Stability ◽  
Tightening Torque ◽  
Mechanical Cycling ◽  
Single Crown ◽  
Implant Abutment ◽  
Kolmogorov Smirnov ◽  
Torque Values ◽  
Tapered Connection ◽  
Abutment Screw

The biomechanical stability of the implant-abutment connection is critical for the success of implant-supported restorations. This study investigated the effect of a positioning index on the abutment screw preload values of tapered connection implants. Twenty Morse taper implants presenting an internal locking hex received 10 solid and 10 straight screw retained abutments for cemented single-crown restorations. Ten abutments had a positioning index to fit the internal locking hex of the implant (straight), and 10 were locked only by the implant taper (solid). The preload values for each abutment screw after a tightening torque were registered by strain gauges. Prosthetic crowns were placed on each abutment and subjected to mechanical cycling. Detorque forces were applied to each abutment and compared with the initial torque values. Data were statistically analyzed using Kolmogorov-Smirnov and Student t tests. The nonindexed group presented higher initial preload (6.05 N ± 0.95 N) compared with the indexed group (4.88 N ± 0.92 N; P &lt; .05). After cycling, the nonindexed group exhibited less reduction of preload (13.84% ± 6.43%) compared with the indexed group (52.65% ± 14.81%; P &lt; .01). Indexed tapered abutments for single-crown restorations might represent greater biomechanical risk under function.

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