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

Cardoso, Mayra; Torres, Marcelo Ferreira; Lourenço, Eduardo José Veras; Telles, Daniel de Moraes; Rodrigues, Rossana Lott; Ribeiro, Ricardo Faria

doi:10.1111/j.1600-0501.2011.02165.x

Cited by 41 publications

(30 citation statements)

References 24 publications

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“…These results are similar to those obtained by Weiss et al10 in 2000 and Cardoso et al11 in 2012, who also found an inverse relationship between the tightening/loosening force and the number of cycles. However, this relationship is not true for the ball/O-ring group, which showed an increase of retention between the first and second year cycles.…”

Section: Discussionsupporting

confidence: 92%

“…In 2012, Cardoso et al11 found no evidences that the replacing of a prosthetic screw procedure alone increases the resistance to loosening, perhaps because a modification had already occurred, possibly due to wear of the internal threads of the implant. Apparently, it is more important to restrict the number of removals than to replace the screw when inserting the definitive restoration.…”

Section: Discussionmentioning

confidence: 99%

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Stability of the prosthetic screws of three types of craniofacial prostheses retention systems

Lanata-Flores

Sigua-Rodríguez

Goulart

et al. 2016

J Korean Assoc Oral Maxillofac Surg

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ObjectivesThis study aimed to evaluate the stability of prosthetic screws from three types of craniofacial prostheses retention systems (bar-clip, ball/O-ring, and magnet) when submitted to mechanical cycling.Materials and MethodsTwelve models of acrylic resin were used with implants placed 20 mm from each other and separated into three groups: (1) bar-clip (Sistema INP, São Paulo, Brazil), (2) ball/O-ring (Sistema INP), and (3) magnet (Metalmag, São Paulo, Brazil), with four samples in each group. Each sample underwent a mechanical cycling removal and insertion test (f=0.5 Hz) to determine the torque and the detorque values of the retention screws. A servo-hydraulic MTS machine (810-Flextest 40; MTS Systems, Eden Prairie, MN, USA) was used to perform the cycling with 2.5 mm and a displacement of 10 mm/s. The screws of the retention systems received an initial torque of 30 Ncm and the torque values required for loosening the screw values were obtained in three cycles (1,080, 2,160, and 3,240). The screws were retorqued to 30 Ncm before each new cycle.ResultsThe sample was composed of 24 screws grouped as follows: bar-clip (n=8), ball/O-ring (n=8), and magnet (n=8). There were significant differences between the groups, with greater detorque values observed in the ball/O-ring group when compared to the bar-clip and magnet groups for the first cycle. However, the detorque value was greater in the bar-clip group for the second cycle.ConclusionThe results of this study indicate that all prosthetic screws will loosen slightly after an initial tightening torque, also the bar-clip retention system demonstrated greater loosening of the screws when compared with ball/O-ring and magnet retention systems.

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Section: Discussionsupporting

confidence: 92%

Section: Discussionmentioning

confidence: 99%

Stability of the prosthetic screws of three types of craniofacial prostheses retention systems

Lanata-Flores

Sigua-Rodríguez

Goulart

et al. 2016

J Korean Assoc Oral Maxillofac Surg

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“…Cardoso et al12 concluded that screw loosening may pass over 20% with repeated tightening and removing cycles. Consequently detorque data may change with repetations.…”

Section: Discussionmentioning

confidence: 99%

Correlation between microleakage and screw loosening at implant-abutment connection

Şahin

Ayyıldız

2014

J Adv Prosthodont

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PURPOSE. This study aimed to evaluate the correlation between microleakage and screw loosening at different types of implant-abutment connections and/or geometries measuring the torque values before and after the leakage tests. MATERIALS AND METHODS. Three different abutment types (Intenal hex titanium, internal hex zirconium, morse tapered titaniuım) with different geometries were connected to its own implant fixture. All the abutments were tightened with a standard torque value then the composition was connected to the modified fluid filtration system. After the measurements of leakage removal torque values were re-measured. Kruskal-wallis test was performed for non-parametric and one-way ANOVA was performed for parametric data. The correlation was evaluated using Spearman Correlation Test (α=0.05). RESULTS. Significantly higher microleakage was found at the connection of implant-internal hex zirconium abutment. Observed mean torque value loss was also significantly higher than other connection geometries. Spearman tests revealed a significant correlation between microleakage and screw loosening.

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“…As Siamos et al demonstrated, retightening could reduce torque loss by 17%‐19%. However, in most studies, the preload was believed to keep decreasing with the repeated tightening of the screw . Cardoso et al found that the removal torque value continues decreasing with the same tightening torque along the cyclic tightening and loosening of the abutment screw.…”

Section: The Mechanism Of the Abutment Screw Looseningmentioning

confidence: 99%

Mechanism of and factors associated with the loosening of the implant abutment screw: A review

Huang

Wang

2019

J Esthet Restor Dent

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Objective While the loosening of the abutment screw is one of the most common complications in implant‐supported restorations, there is a lack of comprehensive literatures for mechanism of and factors associated with the loosening of the implant abutment screw. The review was to summarize the mechanism of and factors associated with the loosening of the implant abutment screw. Overview A total of 99 relevant articles were included in the literature review. The mechanism of the abutment screw loosening was explained. The factors contributed to abutment screw loosening were divided into five aspects and then expounded respectively. Conclusions The internal connection and abutments with anti‐rotational and conical designs have better resistance to screw loosening. Cantilevers increase the risk of screw loosening. The effect of surface treatment of the abutment screw is unsure. Clinicians need to tighten the abutment screw to the recommended torque while avoiding repeated tightening and loosening, and increase the frequency of follow‐ups to retighten the loosened screws in time. Clinical Significance While the loosening of the abutment screw is one of the most common complications in implant‐supported restorations, there is a lack of comprehensive literatures for mechanism of and factors associated with the loosening of the implant abutment screw. The review was to summarize the mechanism of and factors associated with the loosening of the implant abutment screw, so that clinicians may make better choices in clinical practice.

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

Cited by 41 publications

References 24 publications

Stability of the prosthetic screws of three types of craniofacial prostheses retention systems

Stability of the prosthetic screws of three types of craniofacial prostheses retention systems

Correlation between microleakage and screw loosening at implant-abutment connection

Mechanism of and factors associated with the loosening of the implant abutment screw: A review

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