Comparison of screw loosening, rotation, and deflection among three implant designs

Dixon, Donna L.; Breeding, Larry C.; Sadler, J. P.; McKay, Matthew L.

doi:10.1016/s0022-3913(05)80134-9

Cited by 153 publications

(171 citation statements)

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“…Other studies also compared plastic, pre-machined and machined abutments and concluded that lower preload has developed for all components subjected to casting 15,21,30 . This study confirms such results and shows that casting procedures can decrease detorque values even in pre-machined cast abutments, like those used.…”

mentioning

confidence: 99%

“…This study confirms such results and shows that casting procedures can decrease detorque values even in pre-machined cast abutments, like those used. The reason seems to be the irregularities and roughness of contacting surfaces that may result from the casting process, which causes greater embedment relaxation and consequent preload loss 15,30 . The applied torque is distributed to the friction between the screw and the abutment, and between the threads of the screw and the implant, causing loosening.…”

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confidence: 99%

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Screw loosening of different UCLA-type abutments after mechanical cycling

Junqueira¹,

Ribeiro²,

Faria³

et al. 2013

Braz. J. Oral Sci.

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Aim: To evaluate the loss of applied torque (detorque) values in cast and pre-machined abutments for external hex abutment/implant interface of single implant-supported prostheses subjected to mechanical cycling. Methods: Ten metal crowns were fabricated using two types of UCLA abutments: cast and pre-machined with metal base in NiCrTi alloy and tightened to regular external hex implants with a titanium alloy screw, with an insertion torque of 32 N.cm, measured with a digital torque gauge. Samples were embedded with autopolymerizing acrylic resin in a stainless steel cylindrical matrix, and positioned in an electromechanical machine. Dynamic oblique loading of 120 N was applied during 5 x 10 5 cycles. Then, each sample was removed from the resin and detorque values were measured using the same digital torque gauge. The difference of the initial (torque) and final (detorque) measurement was registered and the results were expressed as percentage of initial torque. The results of torque loss were expressed as percentage of the initial torque and subjected to statistical analysis by the Student's t-test (p<0.05) for comparisons between the test groups. Results: Statistical analysis demonstrated that mechanical cycling reduced the torque of abutments without significant difference between cast or pre-machined UCLA abutments (p=0.908). Conclusions: Within the limitations of this in vitro study, it may be concluded that the mechanical cycling, corresponding to one-year use, reduced the torque of the samples regardless if cast or pre-machined UCLA abutments were used.

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mentioning

confidence: 99%

mentioning

confidence: 99%

Screw loosening of different UCLA-type abutments after mechanical cycling

Junqueira¹,

Ribeiro²,

Faria³

et al. 2013

Braz. J. Oral Sci.

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“…[20][21][22][23] The two-piece zirconia abutments also showed competitive results when compared to conventional titanium abutments. 22 A common complication of single or multiple implant restoration is screw loosening.…”

Section: Discussionmentioning

confidence: 98%

“…22 A common complication of single or multiple implant restoration is screw loosening. 23 Screw loosening may occasionally require mechanical repairs. Currently, there is a lack of studies with regard to abutment screw loosening in zirconia abutments with a secondary titanium component.…”

Section: Discussionmentioning

confidence: 99%

Removal torque of a two-piece zirconia abutment with a novel titanium component in an internal connection implant system after dynamic cyclic loading

Lee

2017

J Korean Acad Prosthodont

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IntroductionVarious ceramic materials have been replacing metals in prosthetic fields, including crowns, fixed partial dentures and implant restorations, because of their biocompatibility and optical qualities. When these ceramics were used, the soft tissue appeared more similar to the natural color and the bluish appearance of cervical soft tissues as encountered with metal restorations would be avoided.1 As the esthetic demands of dental patients increase, attempts to use zirconia materials for fabricating monolithic crowns in the posterior region have been widely accepted because of their mechanical properties and biocompatibility. However, when selecting implant abutments for the posterior region, zirconia abutments were not preferred over titanium abutments. 2-4 When using internal connection zirconia abutments, the implant-abutment connection area was vulnerable to cracking or fracture. 5 The development of various zirconia Purpose: The aim of this study was to evaluate screw removal torque of the two-piece zirconia abutment with the novel titanium component compared to the conventional onepiece titanium abutment in the internal connection implant before and after dynamic cyclic loading. Materials and methods: Two types of the abutment assemblies with internal connection were prepared and divided into the groups; titanium abutment-titanium abutment screw assemblies as control, and zirconia abutment-titanium socket-titanium abutment screw assemblies as experimental group. A total of 12 abutments and implants were used of six assemblies each group. Each assembly was tightened to 30 Ncm. A cyclic load of 300 N at an angle of 30 degrees in reference to the loading axis was applied until one million cycles or failure. The removal torque values (RTVs) of the abutment screws were measured with a digital torque gauge before and after cyclic loading. The RTVs of the pre load and post load were analyzed with t-test, and P-values < .05 were considered statistically significant. Results: The assemblies of both groups survived all after the dynamic cyclic loading test without screw loosening. The statistically significant differences were found between the mean RTVs before and after the cyclic loading in both groups (P < .05). The RTV differences for the control and the experimental group were -7.25 ± 1.50 Ncm and -7.33 ± 0.93 Ncm, respectively. Statistical analysis revealed that the RTV differences in both groups were not significantly different from each other (P > .05). Conclusion: Within the limitation of this study, the two-piece zirconia abutment with the titanium component did not show a significant RTV difference of the abutment screw compared to the titanium abutment after dynamic cyclic loading. (J Korean Acad Prosthodont 2017;55:151-5)

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“…Screws were torqued at 32 N as recommended by the manufacturer. After 10 min, the specimens were torqued again (15).…”

Section: Methodsmentioning

confidence: 99%

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

et al. 2015

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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 10 6 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.

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Comparison of screw loosening, rotation, and deflection among three implant designs

Cited by 153 publications

References 4 publications

Screw loosening of different UCLA-type abutments after mechanical cycling

Screw loosening of different UCLA-type abutments after mechanical cycling

Removal torque of a two-piece zirconia abutment with a novel titanium component in an internal connection implant system after dynamic cyclic loading

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

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