A Measurement of Torque Values Obtained With Hand-Held Drivers in a Simulated Clinical Setting

Purpose This study measures the amount of torque that can be applied to the heads of implant screws via hand-held drivers and wrenches in a simulated clinical setting. Materials and Methods Sixty second-year dental students applied their maximum controlled torque to the head of a hex instrument attached to a Tonichi torque gauge mounted in a mannequin. The torque values obtained were recorded, and a mean torque value was calculated. Results The mean torque value obtained in this study was 11.55 N · cm. Conclusions Small-diameter, 10 N · cm gold screws can be adequately tightened with manufacturer-supplied instrumentation. Larger screws requiring more than 10 N · cm of torque cannot be tightened manually using currently available hand-held screwdrivers and hand wrenches.     

Comparison of torque measurements between cortical screws and emergency replacement screws in the cadaver mandible.

The so-called emergency screws are designed for use in a drill hole where the conventional screw has failed following a stripped bone thread. It is not known, however, if these screws are as well anchored in bone as cortical screws, nor is it known how well they secure contact to the previously damaged screw bed. On the basis of torque measurements in mandibles of fresh cadavers, emergency screws were compared with cortical screws. Further, the contact between emergency screw and bone was investigated on interfacial sections after embedding in methyl methacrylate resin. The maximum torque reached during insertion of the AO emergency screws was about 70% of the value measured with 2.7-mm conventional cortical screws and 67% of this value when the 3.2-mm emergency screws were used. While the emergency screws had good contact to the bone in the thread crest area, no bone contact was evident at the bottom of thread groove. This experimental situation can not be entirely extrapolated to the clinical situation. However, the study seems to suggest that emergency screws do not fully meet the demands of rigid internal fixation.     

Effects of Abutment Screw Coating on Implant Preload

Purpose: The aim of the present study was to investigate the effects of tungsten carbide carbon (WC/CTa) screw surface coating on abutment screw preload in three implant connection systems in comparison to noncoated titanium alloy (Ta) screws. Materials and Methods: Preload of WC/CTa abutment screws was compared to noncoated Ta screws in three implant connection systems. The differences in preloads were measured in tightening rotational angle, compression force, initial screw removal torque, and postload screw removal torque after 1 million cyclic loads. Preload loss percent was calculated to determine the efficacy of maintaining the preload of two abutment screw types in relation to implant connection systems. Results: WC/CTa screws provided 10° higher tightening rotational angle than Ta screws in all three connection systems. This difference was statistically significant (p < 0.05). External‐hex butt joint implant connections had a higher compression force than the two internal conical implant connections. WC/CTa screws provided a statistically significantly higher compression force than Ta screws in all three implant connections (p < 0.05). Ta screws required statistically higher removal torque than WC/CTa screws in all three implant connections (p < 0.05); however, Ta screws needed statistically lower postload removal torque than WC/CTa screws in all three implant connections (p < 0.05). Ta screws had a statistically higher preload loss percent than WC/CTa screws in all three implant connections (p < 0.05), indicating that WC/CTa screws were superior in maintaining the preload than Ta screws. Conclusions: Within the limits of present study, the following conclusions were made: (1) WC/CTa screws provided higher preload than noncoated Ta screws in all three implant connection systems. (2) The initial removal torque for Ta screws required higher force than WC/CTa screws, whereas postload removal torque for Ta screws was lower than WC/CTa screws. Calculated Ta screw preload loss percent was higher than for WC/CTa screws, suggesting that WC/CTa screws were more effective in maintaining the preload than Ta screws. (3) Internal conical connections were more effective in maintaining the screw preload in cyclic loads than external‐hex butt joint connections.     

An in vitro comparison of joint stability of implant-supported fixed prosthetic suprastructures retained with different prosthetic screws and levels of fit under masticatory simulation conditions

Purpose: This study sought to determine an optimal postinsertion retorque protocol to maintain implantsuprastructure joint stability after being subjected to a 1-year in vitro masticatory simulation. Materials and Methods: Ten mandibular implant-supported dentures were manufactured and 20 epoxy resin models were obtained for two fit levels: passive fit and misfit. Eight groups (n = 20) were created on the basis of vertical fit (passive or misfit) and prosthetic screw material (titanium or gold). The single-screw test was performed and the vertical misfit was quantified using an optical microscope. Loosening torque was measured after simulations of two types of clinical use: (1) 6 months of use, torque loosening, retightening, another 6 months of use, and loosening torque; and (2) 1 year of use followed by loosening torque. Data were analyzed by means of two-way analysis of variance and the Tukey test. Results: The factors of cycling time and condition use (fit level and screw type), as well the interaction between these factors, significantly influenced the loosening torque (P < .05). After 6 months and another 6 months of clinical use simulation, titanium screws showed higher loosening torque values than did gold screws for the same fit level (P < .05). After 1 year of clinical use simulation, titanium and gold screws in passively fit dentures showed higher loosening torque values than they did in misfit dentures (P < .05). The titanium screws presented a decrease in the loosening torque after 1 year in misfit dentures. Conclusions: The stability of titanium screws was higher than that of gold screws after 6 months of simulation because of their lower plastic deformation. When the cycling time was analyzed, titanium screws were less stable after 1 year of simulation because of loss of torque in the presence of misfit.     

Implant screw mechanics and the settling effect: overview

One of the most serious and prevalent problems associated with the restorative aspect of dental implants is loosening and fracturing of screws. Implant screws should be retightened 10 minutes after the initial torque application as a routine clinical procedure to help compensate for the settling effect. Mechanical torque gauges should be used instead of hand drivers to ensure consistent tightening of implant components to torque values recommended by implant manufacturers.     

不同形态(牙合)面固位螺钉对种植牙牙冠稳定性影响的有限元分析

目的探讨2种不同形态的固位螺钉对修复体稳定性的影响。方法采用三维有限元分析法,对锥形螺钉与平头直角螺钉分别进行实验,计算在相同扭力(200Nmm)下所获得的预负荷值(即夹紧力)及其分布,以及拧紧力矩、防松力矩;在上述扭力下,分别给修复体施加150N和300N垂直向力,比较其预负荷值、拧紧力矩、防松力矩的分布与变化。结果在给予同样扭力(200Nmm)时平头直角螺钉能够获得更大的预负荷;拧紧力矩和防松力矩在螺纹处分布较多,而在螺钉头处分布较少;而锥形螺钉分布相反,力矩主要分布在螺钉头处。在受到150N垂直载荷时,预负荷均下降,其中平头直角螺钉保留的预负荷明显高于锥形螺钉。当受到300N的载荷时,2种螺钉损失的预负荷及力矩值都很大,平头直角螺钉剩余力矩仍然大于锥形螺钉。结论平头直角型面固位螺钉的稳定性优于锥形螺钉。较大载荷会降低修复体的稳定性。     

A rationale method for evaluating unscrewing torque values of prosthetic screws in dental implants

Objectives

Previous studies that evaluated the torque needed for removing dental implant screws have not considered the manner of transfer of the occlusal loads in clinical settings. Instead, the torque used for removal was applied directly to the screw, and most of them omitted the possibility that the hexagon could limit the action of the occlusal load in the loosening of the screws. The present study proposes a method for evaluating the screw removal torque in an anti-rotational device independent way, creating an unscrewing load transfer to the entire assembly, not only to the screw.

Material and methods

Twenty hexagonal abutments without the hexagon in their bases were fixed with a screw to 20 dental implants. They were divided into two groups: Group 1 used titanium screws and Group 2 used titanium screws covered with a solid lubricant. A torque of 32 Ncm was applied to the screw and then a custom-made wrench was used for rotating the abutment counterclockwise, to loosen the screw. A digital torque meter recorded the torque required to loosen the abutment.

Results

There was a significant difference between the means of Group 1 (38.62±6.43 Ncm) and Group 2 (48.47±5.04 Ncm), with p=0.001.

Conclusion

This methodology was effective in comparing unscrewing torque values of the implant-abutment junction even with a limited sample size. It confirmed a previously shown significant difference between two types of screws.     

Biomechanical comparison of four different miniscrew types for skeletal anchorage in the mandibulo-maxillary area

This study compared four miniscrew types for skeletal anchorage (Aarhus, FAMI, Dual Top and Spider) regarding their biomechanical properties contributing to primary stability. Insertion torque measurements and pull-out tests in axial (0 degrees ) as well as in the 20 degrees and 40 degrees direction were performed. Stiffness of the screw-bone construct was calculated from the load-displacement curve. Conic FAMI and Dual Top screws had higher insertion torques. Insertion torques were raised by drill-free insertion of FAMI and Dual Top screws. Statistically significant differences were found between the 4 screw types in pull-out tests. The highly significant differences between the four screws for peak load in the axial (0 degrees ) and 20 degrees direction were not apparent in 40 degrees angular loads. For the conical screws, peak load values increased in angular compared with axial load. The Dual Top screw achieved the highest values for peak load and stiffness. 12 Dual Top and 1 Spider screw heads fractured in the pull-out tests. A conical drill-free screw design achieves higher primary stability compared with cylindrical self-tapping screws. This effect was more obvious in insertion torque estimations rather than in pull-out tests. The Dual Top screws, although biomechanically superior to other screw types, were most prone to fractures.     

A clinical study of the efficacy of gold-tite square abutment screws in cement-retained implant restorations

PURPOSE: The purpose of this study was to record the effectiveness of Gold-Tite square abutment screws, tightened to 35 Ncm with a torque indicator, in maintaining a clinically stable implant/abutment connection. MATERIALS AND METHODS: The study consisted of 73 patients who were treated with 110 Osseotite implants. All patients were restored with either pre-machined titanium or customized UCLA hexed abutments. All abutments were fabricated per the Gold Standard ZR abutment design of Implant Innovations. All of the abutment screws were Gold-Tite square abutment screws. They were torqued to 35 Ncm with a torque indicator at the time of abutment connection. All crown restorations were cemented to the abutments. Patients were followed for at least 1 year post-occlusal loading. RESULTS: Four patients with 6 implants were lost between the 6- and 12-month recall appointments. Clinical assessments of implant/restoration mobility were made by the author. One abutment screw was found to be loose at the 12-month recall appointment, representing a 99% survival rate. DISCUSSION: These results add to the growing evidence that abutment screws with enhanced surfaces may provide increased screw/implant contact, higher rotational values, and calculated preload values. CONCLUSION: The use of the Gold-Tite square abutment screws, torqued to 35 Ncm, maintained a stable implant/abutment connection that was successful in clinical practice for this minimal evaluation period.     

Loosening torque of Universal Abutment screws after cyclic loading: influence of tightening technique and screw coating

PURPOSE

The purpose of this study was to evaluate the influence of tightening technique and the screw coating on the loosening torque of screws used for Universal Abutment fixation after cyclic loading.

MATERIALS AND METHODS

Forty implants (Titamax Ti Cortical, HE, Neodent) (n=10) were submerged in acrylic resin and four tightening techniques for Universal Abutment fixation were evaluated: A - torque with 32 Ncm (control); B - torque with 32 Ncm holding the torque meter for 20 seconds; C - torque with 32 Ncm and retorque after 10 minutes; D - torque (32 Ncm) holding the torque meter for 20 seconds and retorque after 10 minutes as initially. Samples were divided into subgroups according to the screw used: conventional titanium screw or diamond like carbon-coated (DLC) screw. Metallic crowns were fabricated for each abutment. Samples were submitted to cyclic loading at 10⁶ cycles and 130 N of force. Data were analyzed by two-way ANOVA and Tukey''s test (5%).

RESULTS

The tightening technique did not show significant influence on the loosening torque of screws (P=.509). Conventional titanium screws showed significant higher loosening torque values than DLC (P=.000).

CONCLUSION

The use of conventional titanium screw is more important than the tightening techniques employed in this study to provide long-term stability to Universal Abutment screws.     

Comparison of "Look-Alike" Implant Prosthetic Retaining Screws

Purpose The maximum preload torque of implant prosthetic retaining screws from four manufacturers and of two alloy types was measured to determine one index of interchangeability of intersystem components. Materials and Methods Implant prosthetic retaining screws from four manufacturers (3i Implant Innovations Inc, West Palm Beach, FL; Impla-Med Inc, Sunrise, FL; Nobelpharma USA Inc, Chicago, IL; and Implant Support Systems Inc, Irvine, CA) and of two metal types (gold and titanium) were investigated using an in vitro simulation model. Five screws of each type were tightened down against a gold cylinder using a Tohnichi BTG-6 torque gauge (Tohnichi American Corporation, Northbrook, IL) until fracture occurred. Results The 3i Implant Innovations gold and the Nobelpharma gold were not significantly different. The 3i Implant Innovations titanium and the Impla-Med gold were able to withstand less preload torque than the 3i Implant Innovations gold and the Nobelpharma gold. The Implant Support Systems titanium was able to withstand significantly more preload torque than all of the other screws. Conclusions Interchanging implant prosthetic retaining screws could introduce new and unknown variables that may affect the long-term survival of implant fixtures and/or the implant prostheses.     

Relationship between implant preload and screw loosening on implant-supported prostheses

The purpose of this study was to determine whether varying the preload on the implant-abutment complex would affect screw loosening under simulated loading conditions. Abutment screws in sample models were tightened to 25, 30, 35, and 40 N-cm. One group of samples was allowed to stand for 3 hours after being torqued and then loosened. Another group of samples was retorqued after 10 minutes with the same initial torque value and then allowed to stand for 3 hours before loosening. For the load group of samples, the abutments were torqued into place, retorqued after 10 minutes, and a load applied for 3 hours before loosening. Cyclic loading was carried out using a servo-hydraulic testing machine with the values cycled between 1 and 26 pounds and the load applied directly to the abutments. Analysis of variance, analysis of covariance, and linear regression analysis was performed. Within the parameters of this in vitro investigation, the following recommendations can be made: (1) retightening abutment screws 10 minutes after the initial torque applications should be routinely performed and (2) increasing the torque value for abutment screws above 30 N-cm can be beneficial for abutment-implant stability and to decrease screw loosening.     

The use of linear occlusion to treat a patient with combination syndrome: a clinical report

STATEMENT OF PROBLEM: The gold screw of an implant is put under tension during fastening. An increase in operator-induced compressive axial force during fastening may diminish screw tension, lower the friction between the screw threads, and allow for increased tightening torque. PURPOSE: This study was undertaken to assess and compare the compressive axial forces and torques placed simultaneously on implant gold screws by persons with varying degrees of expertise. MATERIAL AND METHODS: A calibrated electric torque driver was used to fasten implant gold screws. Three groups of operators with various levels of implant experience (faculty [F; n = 4], prosthodontic residents [R; n = 4], and undergraduate dental students [S; n = 6]) were asked to repeatedly tighten and loosen a new gold abutment screw into a standard 3.75-mm diameter Branemark abutment. Compressive axial forces during torquing were assessed over the tightening time by means of a miniature load cell adapted to the electric torque driver. Each operator repeated the experiment 3 times after calibration. Within operator and between operator reliability were evaluated. RESULTS: Loosening compressive axial forces were always higher than tightening compressive axial forces, and peak torque was less on loosening than tightening. Faculty placed a smaller range of forces on the screws (mean = 3.29 N, SD +/- 1.45 N) than did the residents (mean = 2.74 N, SD +/- 1.96) or the students (mean = 3.01 N, SD +/- 2.54). CONCLUSION: The clinical experience of operators seems to influence their application of compressive axial force during gold screw tightening. Less torque during unfastening of gold screws seems to be related to increased axial loading.     

Torsion strength of biodegradable and titanium screws: a comparison.

PURPOSE: To determine 1) the differences in maximum torque between 7 biodegradable and 2 titanium screw systems, and 2) the differences of maximum torque between "hand tight" and break of the biodegradable and the titanium osteofixation screw systems. MATERIALS AND METHODS: Four oral and maxillofacial surgeons inserted 8 specimens of all 9 screw systems in polymethylmethacrylate plates. The surgeons were instructed to insert the screws as they would do in the clinic (hand tight). The data were recorded by a torque measurement meter. A PhD resident inserted 8 specimens of the same set of 9 screw systems until fracture occurred. Likewise, the maximum applied torque was recorded. RESULTS: 1) The mean maximum torque of the 2 titanium screw systems was significantly higher than that of the 7 biodegradable screw systems, and 2) the mean maximum torque for hand tight was significantly lower than for break in 2 biodegradable, and both titanium screw systems. CONCLUSIONS: Based on the results, we conclude that the 1.5 mm and 2.0 mm titanium screw systems still present the highest torque strength compared with the biodegradable screw systems. When there is an intention to use biodegradable screws, we recommend the use of 2.0 mm BioSorb FX (Linvatec Biomaterials Ltd, Tampere, Finland), 2.0 mm LactoSorb (Walter Lorenz Surgical Inc, Jacksonville, FL), or the larger 2.5 mm Inion (Inion Ltd, Tampere, Finland) screws.     

Torque removal evaluation of prosthetic screws after tightening and loosening cycles: an in vitro study

Objectives: The aim of this study was to evaluate the variation in removal torque of implant prosthetic abutment screws after successive tightening and loosening cycles, in addition to evaluating the influence of the hexagon at the abutment base on screw removal torque. Material and methods: Twenty hexagonal abutments were tightened to 20 regular external hex implants with a titanium alloy screw, with an insertion torque of 32 N cm, measured with a digital torque gauge. The implant/abutment/screw assemblies were divided into two groups: (1) abutments without hexagon at the base and (2) abutments with a hexagon at the base. Each assembly received a provisional restoration and was submitted to mechanical loading cycles. After this, the screws were removed and the removal torque was measured. This sequence was repeated 10 times, then the screw was replaced by a new one, and another cycle was performed. Linear regression analysis was performed. Results: Removal torque values tended to decrease as the number of insertion/removal cycles increased, for both groups. Comparisons of the slopes and the intercepts between groups showed no statistical difference. There was no significant difference between the mean values of last five cycles and the 11th cycle. Within the limitations of this in vitro study, it was concluded that (1) repeated insertion/removal cycles promoted gradual reduction in removal torque of screws, (2) replacing the screw with a new one after 10 cycles did not increase resistance to loosening, and (3) removal of the hexagon from the abutment base had no effect on the removal torque of the screws. To cite this article :
Cardoso M, Torres MF, Lourenço EJV, de Moraes Telles D, Rodrigues RCS, Ribeiro RF. Torque removal evaluation of prosthetic screws after tightening and loosening cycles: an in vitro study.
Clin. Oral Impl. Res. 23 , 2012 475–480.
doi: 10.1111/j.1600‐0501.2011.02165.x     

Evaluation of screw loosening on new abutment screws and after successive tightening

This study evaluated the loss of the torque applied after use of new screws and after successive tightening. Four infrastructures (IE), using UCLA castable abutment type, were cast in cobalt-chromium alloy and new abutment screws (G1) were used in a first moment. Subsequently, the same abutment screws were used a second time (G2) and more than two times (G3). The values of the torques applied and detorques were measured with a digital torque wrench to obtain the values of initial tightening loss (%). Data were analyzed by ANOVA and Tukey's test (?=0.05). Significant differences were observed between the G1 (50.71% ± 11.36) and G2 (24.01% ± 3.33) (p=0.000) and between G1 (50.71% ± 11.36) and G3 (25.60% ± 4.64) (p=0.000). There was no significant difference between G2 and G3 (p=0.774). Within the limitations of the study, it may be concluded that the percentage of the initial torque loss is lower when screws that already suffered the application of an initial torque were used, remaining stable after application of successive torques.     

Effect of washers on reverse torque displacement of dental implant gold retaining screws.

STATEMENT OF THE PROBLEM: Gold screw loosening is a frequent problem that affects dental implants. PURPOSE: This study determined the effect of spring washers on gold screw displacements during applied removal torque in dental implants. MATERIAL AND METHODS: A 3-unit fixed partial denture was cast in semiprecious alloy and fixed to 2 dental implants with gold-retaining screws. Implants were embedded in acrylic resin and restrained from movement. A miniature load sensor was attached to a torque controller handpiece to accurately measure the time and torque needed to completely loosen the gold screws. Rotational displacements were calculated for 4 experimental setups, involving washers placed on (a) both, (b) the mesial, (c) the distal, and (d) no implants. Screw displacement data were compared between implants in all 4 combinations by means of paired t tests. RESULTS: Gold screws with underlying conical spring washers underwent on average up to 35% (14.1 microm) more rotational displacement during applied removal torque than those without washers. CONCLUSION: Inclusion of a conical spring washer significantly increased the amount of rotational displacement needed to completely loosen an implant gold retaining screw.     

Self-adapting washer system for lag screw fixation of mandibular fractures. Part II: In vitro mechanical characterization of 2.3 and 2.7 mm lag screw prototypes and in vivo removal torque after healing.

The aim of this study was to mechanically characterize self-tapping 2.3 and 2.7 mm titanium lag screw prototypes which are part of the newly developed 'self-adapting washer' maxillofacial lag screw osteosynthesis system. In vitro in a screw testing machine the insertion torque, maximum locking torque and axial force and the ultimate torsional strength were assessed. In vivo in six miniature pigs using a mandibular symphyseal fracture model, the removal torques after 3 and 6 months of healing were measured. Additionally the bone-metal contact (BMC) of the screws was assessed histometrically. The maximum insertion torque (0.185 Nm) was far below the mechanical limits of the screws (2.3 mm = 0.96 Nm, 2.7 mm = 1.6 Nm). A tightening of the 2.7 mm screw with an axial force of 1000 N and of the 2.3 mm screw with 500-550 N leaves a safety margin of approximately one-third on the ultimate torsional strength. Clinically these values permit the use of two 2.3 mm lag screws or one 2.7 mm lag screw in mandibular symphysis fractures since 1000 N tensile axial force are required in this indication. During screw removal after 6 months healing, torque levels close to the mechanical limits of the screws were recorded and screw failures were observed. This failure rate may have been due to the BMC of 49.8% which was in the range of titanium dental implants. Accordingly the screw heads were reinforced to prevent fractures.     

Wave analysis of implant screw loosening using an air cylindrical cyclic loading device

STATEMENT OF PROBLEM: The mechanics of implant screw loosening or fracture are well understood in the field of engineering. They have not been as widely explored in dentistry. PURPOSE: This study investigated the effects of simulated mastication on implant components and used wave analysis to document the basic mechanisms of screw loosening in a simulated oral environment. MATERIAL AND METHODS: A pneumatic cylindrical cyclic loading device was fabricated to simulate masticatory movement. Thirteen standard abutments were connected on external hexagonal implants with titanium abutment screws tightened to 20 Newton centimeters (Ncm), and single crowns were retained with gold screws tightened to 10 Ncm on each abutment, respectively. Ten single-implant crowns were loaded with the use of a cyclic loading device with 100 N of force at 30 degrees angles to the long-axis for 0.2 seconds of contact time with a frequency of 1 Hz. Three crowns were loaded vertically under the same conditions to serve as the control group. The effects of up to 1 million cyclic loads and various tightening torque forces (2, 4, 6, 8, 10, and 12 Ncm) on screw loosening were evaluated by wave analysis. A software program was written to record every wave mode and to stop the machine automatically if the amount of horizontal displacement of the crown was more than 0.5 mm, which was designated to represent perceptible loosened implant crown mobility clinically. The general wave patterns and characteristics of loosened and stable screws and the effect of various tightening torques were analyzed by comparing the differences in wave patterns. RESULTS: The wave mode was divided into 4 stages for loosened gold screws: initial displacement, initial vibration, elastic deformation, and recovery stage. However, the initial displacement and initial vibration stages were not discernible for stable gold screws. Of the 10 gold occlusal screws, 4 loosened before the 1 million cyclic loads in the 10 single crowns tested. There was no screw loosening in the control group. There was no effect of screw loosening on the elastic deformation stage. CONCLUSION: Within the limitations of this study, tightening torque had a significant effect on screw loosening. It would appear that more than 10 Ncm of tightening torque should be recommended for the gold screws in this external hexagon implant system.     

Screw loosening for standard and wide diameter implants in partially edentulous cases: 3- to 7-year longitudinal data

Screw loosening is considered to be a common problem with both screw-retained and cemented implant restorations. A wider abutment platform, as well as using a torque driver to tighten specifically designed screws may help prevent this loosening. However, there has been no clinical study evaluating either of these. To longitudinally compare the frequency of screw loosening in standard diameter, (3.75 and 4.0 mm) implant supported prostheses to that of wide diameter, (5.0 and 6.0 mm) implant supported prostheses that were hand tightened, and to evaluate whether using a torque driver would minimize or prevent this problem, if screw loosening occurred. A total of 213 dental implants in 106 patients were included in this prospective longitudinal study. Of the implants 68 were wide diameter and 145 were standard diameter implants. Wide diameter implants showed 5.8% screw loosening, while standard diameter implants showed 14.5% screw loosening after insertion with only hand torquing. When these loose screws were tightened with a torque driver, there was no more loosening of screws. Within the limitations of this study, the wide diameter implants tested showed less screw loosening than the standard diameter implants when hand torqued. Additionally, within the scope of our study, using a torque driver to tighten the screws with the recommended force prevented this loosening from reoccurring in all cases.