Fracture of abutment screw supporting a cemented implant-retained prosthesis with external hexagon connection: a case report with sem evaluation

Santos, Mariana Diniz Bisi dos; Pfeifer, Arthur Braga; Silva, Marcos Rogério Pupo; Sendyk, Cláudio Luiz; Sendyk, Wilson Roberto

doi:10.1590/s1678-77572007000200015

Cited by 14 publications

(13 citation statements)

References 3 publications

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“…9,14 The absence of passivity between components has also been shown to increase stress in the screw and results in metal fatigue failure and screw loosening. 17,18 Narrow-diameter implants (3.0 to 3.4 mm) were recently developed. 17,18 Narrow-diameter implants (3.0 to 3.4 mm) were recently developed.…”

Section: Introductionmentioning

confidence: 99%

The Effect of Repeated Torque in Small Diameter Implants with Machined and Premachined Abutments

Saboury

Asli

Vaziri

2012

Clin Implant Dent Rel Res

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Background: Detorquing value is an important factor in the amount of preload stresses during abutment screw fastening. This study evaluated the percentage of detorque values in two‐piece machined titanium and premachined cast abutments in small diameter implants. Materials and Methods: Three groups of five samples were evaluated. Group 1 (G1), machined titanium abutments, group 2 (G2), premachined cast straight abutments that cast with gold‐palladium, and group 3 (G3), premachined angled cast abutments that cast with the same alloy, were angled before casting. Each abutment was torque to 24 Ncm according to the manufacturer's instructions and detorqued five times. The means of detorquing and torquing values in all groups were recorded. The mean of detorque in each group as a percentage of the toque value was calculated. The data for all groups were compared and calculated using analysis of variance (ANOVA) and t‐test. Results: Mean detorque values in G1, G2, and G3 were 88.1 ± 1.69, 93.1 ± 2.68, and 80.9 ± 4.95%, respectively. The ANOVA showed significant differences in mean of applied detorque (p < .001) and torque (p = .06) tightening among different groups. G2 had significantly greater detorque values (p < .05). No significant differences were found between G1 and G2. Surprisingly, abutment screw fracture occurred in three samples of G3. Conclusions: G3 showed significant percentage torque reduction (p < .05) and exhibited abutment screw fracture during evaluation. G2 presented the lowest torque reduction. Screw fracture occurred only in G3.

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Section: Introductionmentioning

confidence: 99%

The Effect of Repeated Torque in Small Diameter Implants with Machined and Premachined Abutments

Saboury

Asli

Vaziri

2012

Clin Implant Dent Rel Res

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“…De acordo com Santos et al 8 , o modelo e material utilizados na confecção dos componentes implantossuportados influenciam claramente nos processos de deformação plástica, desgaste ou falha das peças protéticas. No presente estudo, não houve essa relação entre modelo, material e falhas, já que os tipos de pilares testados são do mesmo material e comportaram-se de maneira semelhante no que diz respeito à resistência às cargas e ao local de fratura dos implantes, apesar de possuírem modelos diferentes.…”

Section: Discussionunclassified

“…Adicionalmente, a má adequação do quadro clínico, como a presença de desajuste oclusal, conduzindo à fadiga do material, e falhas intrínsecas dos componentes, como defeitos de usinagem, podem estar relacionadas à fratura desses elementos 7,8 .…”

Section: Introductionunclassified

Análise da resistência à fratura entre pilares retos e angulados do sistema cone Morse

Santos

Trento

Santos

et al. 2015

Rev. odontol. UNESP

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ResumoObjetivo: Analisar a resistência à fratura por fadiga dos conjuntos implante-pilar, nos tipos reto e angulado, submetidos a cargas cíclicas similares às mastigatórias. Material e método: Foram utilizados 32 implantes (3,75 × 11 mm) com sistema cone Morse e 32 pilares, separados em dois grupos: pilares retos e angulados (n=16) (Neodent, Curitiba, PR, Brasil). Os conjuntos foram submetidos a testes cíclicos em equipamento servo-hidráulico, fixando-se o número de ciclos em cinco milhões. Conclusão: Os dois tipos de pilares (retos e angulados), em condições in vitro, comportaram-se estatisticamente de forma semelhante, sendo aceita a hipótese nula de que não há diferença de resistência à fratura entre os grupos.Descritores: Implantes dentários; resistência de materiais; fenômenos mecânicos. AbstractObjective: The aim of this study was to verify the fatigue fracture resistance of the implant-abutment joint, in straight and angled types, subject to cyclic loads similar to chewing. Material and method: It was used 32 implants system (3.75 × 11mm) with Morse taper and 32 abutment, divided in two groups: abutment straight and angled (n = 16) (Neodent, Curitiba, PR, Brazil). The sets were submitted to cyclic testing using servo-hydraulic equipment, fixing the number of cycles at 5 million. It was evaluated the number of cycles, load and moment force of the samples. The Fisher test and ANOVA were applied (p<0,005). Fractured samples were analyzed in the scanning electron microscopy (SEM). Result: Straight abutment, four resisted the cycles number established, supporting loads between 470N and 510N. Angled abutment: nine resisted to loads between 570N and 890N. Regarding the fractured samples below the number of cycles, in the straight abutment, nine fractured with loads between 470N and 630N. In the angled abutment, five fractured with loads ranging from 760N and 890N. The moment of the force was calculated for each joint implant-abutment (Averages: Straight Group -4335,23Nmm, angled Group -3923,37Nmm). Conclusion: Two types of abutments (straight and angled), in vitro conditions, statistically behaved similarly, and accepts the null hypothesis that there is no difference in fracture resistance between groups.Descriptors: Dental implants; material resistance; mechanical phenomena. INTRODUÇÃOO uso de implantes dentários osseointegrados tornou-se modalidade previsível de reabilitação bucal, confi rmada pelo alto sucesso em restaurações unitárias, parciais ou completas dos arcos edêntulos 1,2 . Entretanto, apesar do sucesso dos implantes osseointegrados, problemas de ordem mecânica, como a soltura ou fratura do pilar, o afrouxamento do parafuso de fi xação de coroas unitárias e a instabilidade protética, são problemas comumente relatados na literatura 3 .Durante os movimentos mastigatórios, os dentes naturais e os componentes protéticos são submetidos a cargas geradas pelo contato entre elementos antagonistas, de forma direta ou através da interposição de alimentos 4,5 . São geradas tensões na coroa a partir

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“…11,12 Abutment screw fractures are associated with inadequate screw tightening, screw loosening, improper occlusion concept, premature occlusal contacts, parafunctional habits, cervical misfit of the prosthesis and consequent fatigue of the screw material, fatigue character and yielding strength of the screw material, and fabrication failures. 4,6,11,13,14 Fractured abutment screws may be replaced by new abutment screws. However, sometimes, the screw cannot be removed and the entire implant must be surgically removed and replaced.…”

Section: Introductionmentioning

confidence: 99%

“…However, sometimes, the screw cannot be removed and the entire implant must be surgically removed and replaced. 13,14 The physical properties and the design of screws and restorative components dictate their fracture strength and failure mode. 7 Abutment screws can be made from a variety of materials.…”

Section: Introductionmentioning

confidence: 99%

Fracture resistance of abutment screws made of titanium, polyetheretherketone, and carbon fiber-reinforced polyetheretherketone

2014

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Fractured abutment screws may be replaced; however, sometimes, the screw cannot be removed and the entire implant must be surgically removed and replaced. The aim of this study was to compare the fracture resistance of abutment retention screws made of titanium, polyetheretherketone (PEEK) and 30% carbon fiber-reinforced PEEK, using an external hexagonal implant/UCLA-type abutment interface assembly. UCLA-type abutments were fixed to implants using titanium screws (Group 1), polyetheretherketone (PEEK) screws (Group 2), and 30% carbon fiber-reinforced PEEK screws (Group 3). The assemblies were placed on a stainless steel holding apparatus to allow for loading at 45 o off-axis, in a universal testing machine. A 200 N load (static load) was applied at the central point of the abutment extremity, at a crosshead speed of 5 mm/minute, until failure. Data was analyzed by ANOVA and Tukey's range test. The titanium screws had higher fracture resistance, compared with PEEK and 30% carbon fiber-reinforced PEEK screws (p < 0.05). In contrast, no statistically significant difference was observed between the fracture resistance of the PEEK and the 30% carbon fiber-reinforced PEEK screws (p > 0.05). Finally, visual analysis of the fractions revealed that 100% of them occurred at the neck of the abutment screw, suggesting that this is the weakest point of this unit. PEEK abutment screws have lower fracture resistance, in comparison with titanium abutment screws.

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Fracture of abutment screw supporting a cemented implant-retained prosthesis with external hexagon connection: a case report with sem evaluation

Cited by 14 publications

References 3 publications

The Effect of Repeated Torque in Small Diameter Implants with Machined and Premachined Abutments

The Effect of Repeated Torque in Small Diameter Implants with Machined and Premachined Abutments

Análise da resistência à fratura entre pilares retos e angulados do sistema cone Morse

Fracture resistance of abutment screws made of titanium, polyetheretherketone, and carbon fiber-reinforced polyetheretherketone

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