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Agustín-Panadero R, Baixauli-López M, Fernández-Estevan L, Senent-Vicente G, Revilla-León M, Gómez-Polo M. Resistance to loosening of intentionally shortened screws used to solve the unsuccessful removal of fractured prosthetic screws. J Prosthet Dent 2024; 132:165-171. [PMID: 37596156 DOI: 10.1016/j.prosdent.2023.06.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 06/27/2023] [Accepted: 06/29/2023] [Indexed: 08/20/2023]
Abstract
STATEMENT OF PROBLEM Fractured prosthetic implant screws cannot be removed in all patients, ultimately leading to the removal of the implant. Whether an intentionally shortened prosthetic implant screw (SPIS) can provide adequate retention is unclear. PURPOSE The purpose of this in vitro study was to evaluate the resistance to loosening of SPISs engaging the remaining coronal internal threads as a possible solution to maintaining both implant and restoration. MATERIAL AND METHODS Fifty grade V titanium SPISs were used to tighten 50 titanium transepithelial abutments on implants to 30 Ncm. The specimens were distributed into 5 groups (n=10) according to the conditions under which the screws were secured to manufacturer-recommended preload: dry (D), moistened in saliva (AS), moistened in chlorhexidine (CLHX), wrapped in polytetrafluoroethylene tape (PTFE), and resin cemented (RE). All groups were subjected to a cyclic loading test (240 000 cycles). The reverse torque value (RTV) of the SPIS was registered twice: 24 hours after initial tightening (T1); and after retightening and the cyclic loading test (T2). The resultant RTV was compared with the 30-Ncm tightening torque to assess torque loosening. The Kruskal-Wallis and Mann-Whitney tests were used for the comparisons between groups and the Wilcoxon test for the intragroup comparisons (α=.05 with Bonferroni correction). RESULTS At T1, all groups found lower mean±standard deviation RTVs than the reference tightening torque (30 Ncm) (D 24.82±2.34 Ncm, AS 25.56±2.89 Ncm, PTFE 26.02±2.26 Ncm, CLHX 26.26±1.82 Ncm), except the resin-cemented group, which increased its RTV (RE 44.01±19.94 Ncm). At T2, all the groups found lower RTVs than the reference tightening torque, and the torque values at T1 (D 19.81±6.59 Ncm, CLHX 18.98±6.36 Ncm, AS 21.28±7.32 Ncm), with the exception of PTFE (24.07±3.41 Ncm) and RE (41.47±21.68 Ncm), where RTV was similar to that recorded at T1. At T1, significant differences were found among the groups (P=.024). At T2, after cyclic loading, the RE group found the highest RTV, reporting significant differences with the D and CHLX groups (P<.05) and statistically similar to the AS group (P=.068). CONCLUSIONS PTFE-wrapped screws found similar RTVs after the fatigue test than dry, moistened with saliva, and moistened with chlorhexidine screws. Resin-cemented shortened prosthetic implant screws were found to be the most resistant to loosening after cyclic loading.
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Affiliation(s)
- Rubén Agustín-Panadero
- Associate Professor, Department of Stomatology, Faculty of Medicine and Dentistry, Universitat de València, Valencia, Spain
| | - Mar Baixauli-López
- Adjunct Professor, Department of Stomatology, Faculty of Medicine and Dentistry, Universitat de València, Spain.
| | - Lucía Fernández-Estevan
- Associate Professor, Department of Stomatology, Faculty of Medicine and Dentistry, Universitat de València, Valencia, Spain
| | - Gisela Senent-Vicente
- Adjunct Professor, Department of Stomatology, Faculty of Medicine and Dentistry, Universitat de València, Spain
| | - Marta Revilla-León
- Affiliate Faculty, Graduate Prosthodontics University of Washington, Seattle, Wash; Affiliate Faculty, Research and Digital Dentistry, Kois Center, Seattle, Wash; Affiliate Faculty, Researcher, Revilla Research Center, Madrid, Spain
| | - Miguel Gómez-Polo
- Associate Professor, Department of Prosthetic Dentistry, Faculty of Dentistry, Complutense University of Madrid, Madrid, Spain; Director of Postgraduate Program, School of Dentistry, Complutense University of Madrid, Madrid, Spain
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Shemtov-Yona K, Arieli A, Barhum M, Pilo R, Levartovsky S. The effect of contaminating media on the static and dynamic mechanical resilience of dental implant abutments' screws: In vitro study. Clin Implant Dent Relat Res 2024; 26:289-298. [PMID: 37675656 DOI: 10.1111/cid.13271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 07/15/2023] [Accepted: 08/21/2023] [Indexed: 09/08/2023]
Abstract
INTRODUCTION This in vitro study aims to biomechanically evaluate the influence of medium contamination for example, saliva, blood, chlorhexidine (liquid and gel), and fluoride mouthwash on the biomechanical behavior of implant abutments' screws under static and dynamic loading. METHODS Forty five Ti6Al4V commercial dental implants and abutments were tested in this study. Two main mechanical tests were carried out in the selected media. The first, static, aimed to evaluate the torque loss after the first tightening. The second, dynamic, involved a random cyclic load range between 0 and 200 N to evaluate torque loss due to mastication. In addition, metallographic longitudinal and cross-sections of the abutment-implant apparatus were examined to evaluate the abutment screw-abutment-implant interface. RESULTS The static torque test showed that irrespective of the media, no statistical difference in static torque loss was found prior to dynamic loading. For the dynamic tests, torque-angle evolution analysis during tightening to 30 Ncm and after the spectrum loading, showed the same global mechanical behavior for all media, but the statistical analysis indicated a difference between the groups in reverse torque values (RTV) and in the torque loss due to dynamic loading. The medium groups CHX, CHX-gel, and Fluoride mouthwash, showed a meaningful torque loss due to loading, but the medium groups, control (no medium), blood and saliva showed an opposite trend and required a higher torque to open the abutment screws. The microstructural analysis revealed clear signs of cold-welding/galling, post-dynamic loading in these latter groups. CONCLUSIONS The presence of lubrication/contamination media (CHX mouthwash/CHX-gel/Fluoride mouthwash) reduces the preload generated due to tightening but prevents damage due to galling. The observed reduction of RTV clearly emphasizes the need for frequent abutment screw retightening for implant-supported prosthetic long-term stability.
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Affiliation(s)
- Keren Shemtov-Yona
- Department of Oral Biology, The Maurice and Gabriela Goldschleger School of Dental Medicine, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Adi Arieli
- Department of Oral Rehabilitation, the Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Mohana Barhum
- The Maurice and Gabriela Goldschleger School of Dental Medicine, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Raphael Pilo
- Department of Oral Biology, The Maurice and Gabriela Goldschleger School of Dental Medicine, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shifra Levartovsky
- Department of Oral Rehabilitation, the Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel
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Lang LK, Karl M, Klär V. Evaluation of different debridement strategies for implant-abutment connections: An in vitro study. J Prosthet Dent 2023; 130:738.e1-738.e8. [PMID: 37739883 DOI: 10.1016/j.prosdent.2023.08.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 08/24/2023] [Accepted: 08/25/2023] [Indexed: 09/24/2023]
Abstract
STATEMENT OF PROBLEM Technical complications, including abutment fracture, are a clinical reality. After retrieving failed components, re-establishing a reliable implant-abutment connection is essential, but recommendations on how to clean the interface are lacking. PURPOSE The purpose of this in vitro study was to evaluate different clinical debridement strategies for removing titanium powder from an implant-abutment interface with regard to their efficacy and associated risk of damaging the interface. MATERIAL AND METHODS Specimens (n=5) were assembled from previously cut implant halves, which were then contaminated by placing titanium powder inside the implant-abutment connection. Activated rinsing, airflow, and an ultrasound scaler, as well as combinations thereof, were then used to clean the implant-abutment connections. Both parts of each specimen were rated under a light microscope with respect to contamination and damage. In addition, abutments were placed in intact implants (n=10), which had previously been contaminated and cleaned, to record torque curves and abutment stability. Statistical analysis of ratings was based on Kruskal-Wallis tests and the Nemenyi All Pairs test with single-step P value correction, while abutment stability and torque were analyzed using analysis of variance and Tukey HSD tests (α=.05). RESULTS Erythritol as an abrasive medium led to significantly greater contamination than the scaler (P=.002), activated rinsing (P=.021), and airflow with sodium bicarbonate combined with either conventional (P=.002) or activated rinsing (P=.007). Greater damage was also observed with erythritol because of accumulations of the abrasive media, while scratches were seen after scaler application. Airflow using sodium bicarbonate in combination with activated rinsing showed the lowest level of damage (versus scaler P=.030). Using conventional (P=.010) or activated (P=.029) rinsing, airflow treatment led to a significant reduction in contamination. The scaler led to a significant decrease in abutment stability (P=.048), while activated rinsing and the combination of airflow and activated rinsing did not significantly affect abutment stability. Abutments placed in implants previously contaminated and cleaned required greater torque as compared with original implants (versus activated rinsing, P=.009). CONCLUSIONS Activated rinsing constituted the best technique for cleaning implant-abutment connections. Cleaning efficiency can be enhanced with airflow using sodium bicarbonate as an abrasive medium.
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Affiliation(s)
- Lilly K Lang
- Graduate student, Department of Prosthodontics, Saarland University, Homburg, Saar, Germany
| | - Matthias Karl
- Professor and Director, Department of Prosthodontics, Saarland University, Homburg, Saar, Germany
| | - Virgilia Klär
- Research Associate, Department of Prosthodontics, Saarland University, Homburg, Saar, Germany..
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Al-Sanea A, Aktas S, Celik T, Kisioglu Y. Effects of the internal contact surfaces of dental implants on screw loosening: A 3-dimensional finite element analysis. J Prosthet Dent 2023; 130:603.e1-603.e11. [PMID: 37643939 DOI: 10.1016/j.prosdent.2023.07.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 07/11/2023] [Accepted: 07/12/2023] [Indexed: 08/31/2023]
Abstract
STATEMENT OF PROBLEM The effects of the internal contact surfaces of dental implants on screw loosening have yet to be investigated. PURPOSE The purpose of this 3-dimensional finite element analysis (FEA) study was to evaluate and compare the mechanical effects of the abutment implant angle (θ), the abutment screw head diameter (D), and the abutment screw length (L) on screw loosening. MATERIAL AND METHODS A total of 27 models presenting various mechanical scenarios were built by using combinations of 3 different θ (30 degrees, 45 degrees, and 60 degrees), D (2.65 mm, 2.75 mm, and 2.85 mm), and L (4 mm, 5 mm, and 6 mm). In FEA, a static test with a 200-N force inclined 30 degrees in the implant axial direction was applied to the upper surface of the abutment to evaluate and compare the maximum von Mises stresses of the implant components and the maximum total deformation in all models. In addition, modal analysis was applied to identify the natural frequencies in all models under free (unforced) vibration, and a Kruskal-Wallis statistical test (α=.05) was performed, followed by multiple pairwise comparisons by using the Dunn test. RESULTS The Kruskal-Wallis test found a significant influence of the θ on implant stress, total deformation, and natural frequency (P<.001). For example, increasing the θ from 30 degrees to 45 degrees and 60 degrees can considerably reduce the model's natural frequencies to 18% and 26%, respectively. Similarly, the test underscored the significant impact of the D on both abutment screw stress and abutment stress (P=.010 and P=.002, respectively). However, the L appeared to have no significant effect on any of the dependent variables (P>.05). CONCLUSIONS The θ and the D significantly influenced the stresses of dental implant components, total deformation, and natural frequency of the model, which may impact the mechanical stability of the screw joint. However, the L does not appear to affect these values significantly.
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Affiliation(s)
- Abdulrahman Al-Sanea
- Graduate student, Department of Biomedical Engineering, Biomechanics Lab, Kocaeli University, Kocaeli, Turkey.
| | - Serkan Aktas
- Lecturer, Uzunciftlik Nuh Cimento Vocational High School, Kocaeli University, Kocaeli, Turkey
| | - Talip Celik
- Associate Professor, Department of Biomedical Engineering, Biomechanics Lab, Kocaeli University, Kocaeli, Turkey
| | - Yasin Kisioglu
- Full Professor, Department of Biomedical Engineering, Biomechanics Lab, Kocaeli University, Kocaeli, Turkey
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Adawi HA, Dewan H, Khawaji A, Akkam H, Hakami A, Wasli B, Hakami M, Alali M, Chohan H. Effects of Blood Contamination and Decontamination Protocol on Reverse Torque Value of Abutment Screws in Dental Implants: An In Vitro Study. Biomimetics (Basel) 2023; 8:biomimetics8020157. [PMID: 37092409 PMCID: PMC10123743 DOI: 10.3390/biomimetics8020157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Revised: 04/05/2023] [Accepted: 04/12/2023] [Indexed: 04/25/2023] Open
Abstract
Background and Objective: Loosening of abutment screws in dental implants is a mechanical complication that affects prosthetic treatments and hence, patient satisfaction. Blood contamination of abutment screws may play a role in this phenomenon. However, only limited research attention has been given to this issue. In the present study, we determined the effect of blood contamination and decontamination protocol on the reverse torque value (RTV) of abutment screws. Materials and Methods: A questionnaire-based survey was sent to 210 implantologists requesting feedback on their attitude to the blood contamination issue and the decontamination protocols used. The survey responses were used in a selection of the decontamination solutions that were used in the subsequent in vitro study on the effects of blood decontamination protocol on the RTV of abutment screws. Thus, three study groups were used (n = 20 abutment screws in each group): Group 1 (control group; blood-contaminated screws); Group 2 (screws decontaminated with 5.25% sodium hypochlorite (NaOCl) solution); and Group 3 (screws decontaminated with normal saline solution (0.9%)). Then, each of the connections were subjected to thermocycling, and RTVs of the screw were measured using a digital torque meter. Intragroup and intergroup RTVs were analyzed for significance using analysis of variance (ANOVA) and Tukey's honestly significant difference (HSD) tests. Results: 48% of the implantologists responded to the survey; 80% of them were concerned with blood contamination in the implant connection, especially before abutment loading and 85% of them used either chlorhexidine solution or normal saline solution as the decontamination agent. The mean RTV for Group 2 screws (30.27 ± 2.8 N.cm) was significantly greater than that for Group 3 screws (26.02 ± 1.99 N.cm) which, in turn, was significantly greater than that for Group 1 screws (23.64 ± 1.84 N.cm). Conclusion: Decontamination of blood-covered connections using 5.25% NaOCl solution or normal saline solution restores the RTV of abutment screws. This finding may have clinical relevance in that the decontaminated screws may contribute to the low incidence of screw loosening and, ultimately, improved patient satisfaction.
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Affiliation(s)
- Hafiz A Adawi
- Department of Prosthetic Dental Sciences, College of Dentistry, Jazan University, Jazan 45142, Saudi Arabia
| | - Harisha Dewan
- Department of Prosthetic Dental Sciences, College of Dentistry, Jazan University, Jazan 45142, Saudi Arabia
| | - Arwa Khawaji
- General Dentist, College of Dentistry, Jazan University, Jazan 45142, Saudi Arabia
| | - Hadeel Akkam
- General Dentist, College of Dentistry, Jazan University, Jazan 45142, Saudi Arabia
| | - Areej Hakami
- General Dentist, College of Dentistry, Jazan University, Jazan 45142, Saudi Arabia
| | - Bashair Wasli
- Dental Intern, College of Dentistry, Jazan University, Jazan 45142, Saudi Arabia
| | - Maram Hakami
- Dental Intern, College of Dentistry, Jazan University, Jazan 45142, Saudi Arabia
| | - Maimonah Alali
- Dental Intern, College of Dentistry, Jazan University, Jazan 45142, Saudi Arabia
| | - Hitesh Chohan
- Department of Restorative Dental Sciences, College of Dentistry, Jazan University, Jazan 45142, Saudi Arabia
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Evaluation the loosening of abutment screws in fluid contamination: an in vitro study. Sci Rep 2022; 12:10797. [PMID: 35750776 PMCID: PMC9232564 DOI: 10.1038/s41598-022-14791-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 06/13/2022] [Indexed: 11/08/2022] Open
Abstract
Screw loosening is one of the most common clinical problems of dental implants. Research on the influencing factors of screw loosening is very important to prevent screw loosening. The purpose of this in vitro study was to evaluate the influence of liquid contamination on the screw loosening. According to the contamination condition, forty-five abutment screws were divided into three groups (n = 15): no contamination, artificial saliva contamination, and mouthwash contamination. The preload and friction coefficient of the abutment screws were recorded. Then, the reverse torque values (RTVs) and settlement were measured after 3.0 × 105 and 6.0 × 105 cycles. The surface wear of the screws was analyzed. Finally, the stress distribution of the abutment screws was calculated by finite element analysis (FEA). The results showed that fluid contamination reduced the friction coefficient, increased the preload, decrease the settlement, improved resistance to screw loosening, and reduced wear on the thread surface. Appropriate antimicrobial lubrication may improve the anti-loosening performance of abutment screws and prevent excessive wear on the threaded surface.
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An In Vitro Study of Fluid Contaminations Influences on Reverse Torque Values of Implant-Abutment Connections. BIOMED RESEARCH INTERNATIONAL 2022; 2022:4111710. [PMID: 35299888 PMCID: PMC8923780 DOI: 10.1155/2022/4111710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Accepted: 02/25/2022] [Indexed: 11/20/2022]
Abstract
Purpose To examine the effects of fluid contamination on the reverse torque value (RTV) of abutment screws. 484 titanium fixtures were mounted into the stainless-steel holders. Methods 11 groups (44 specimens in each group) of implants were mounted in acrylic resin. Ten groups of fixture screw holes were contaminated with chlorhexidine, saliva, blood, fluoride, or combination groups, and one group served as a control without contamination. To simulate the oral environment, samples were subjected to thermal cycling and cyclic loading. Results The RTV means were less than the initial torque in both control and contamination groups. The maximum RTV mean was observed in the fluoride group (26.00 ± 1.02 Ncm). In other groups, this rate for control, blood, saliva, and chlorhexidine groups were 18.00 ± 1.78 Ncm, 22.12 ± 1.56 Ncm, 21.56 ± 1.43 Ncm, and 21.89 ± 1.02 Ncm, respectively. In combination groups, the maximum RTV mean was observed in the saliva+CHX group (23.89 ± 1.92 Ncm). In other combination groups, this rate for the blood+CHX, blood+saliva, saliva+fluoride, fluoride+CHX, and fluoride+blood groups were 22.56 ± 1.73 Ncm, 22.00 ± 1.54 Ncm, 20.11 ± 1.58 Ncm, 23.51 ± 1.19 Ncm, 21.02 ± 1.38 Ncm, and 20.11 ± 1.58 Ncm, respectively. The RTV was statistically significant (p < 0.05) for the contamination groups (except saliva) and combination groups compared to the control group. There is no statistically significant difference (p > 0.05) between the reverse torque value mean of the blood and saliva groups and between that of the fluoride and chlorhexidine groups. Conclusion Implant-abutment specimens are suggested to be placed in a saliva environment and should be subjected to cyclic loading.
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Yilmaz B, Gouveia D, Seghi R, Johnston W, Lang LA. Effect of crown height on the screw joint stability of zirconia screw-retained crowns. J Prosthet Dent 2021; 128:1328-1334. [PMID: 33838917 DOI: 10.1016/j.prosdent.2021.02.027] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 02/12/2021] [Accepted: 02/12/2021] [Indexed: 10/21/2022]
Abstract
STATEMENT OF PROBLEM Medium- to long-term data for the performance of zirconia crowns with titanium (Ti) bases are sparse, particularly when the crown height space and occlusal loads are high. PURPOSE The purpose of this in vitro study was to assess the effect of the height of zirconia screw-retained implant crowns with a Ti base on the screw joint stability after cyclic loading. A secondary aim was to investigate the survival of zirconia crowns of different heights after cyclic loading. MATERIAL AND METHODS Twenty-one internal connection implants were secured between fiberglass-reinforced epoxy resin sleeves. Mandibular first molar monolithic zirconia crowns with 3 different heights (6 mm, 10 mm, and 14 mm) were milled and bonded to the Ti bases (n=7). The screws were tightened to 30 Ncm, and a 30-degree 120-N cyclic load was applied to the crowns at 2 Hz for 5 million cycles. After 5 million cycles, the crowns were evaluated for stability, and the same protocol was repeated for 275-N and 435-N loads for 5 million cycles each. After loading, the detorque values were recorded. Failure was characterized based on whether the crown, screw, and/or implant fracture was observed. The detorque values were analyzed by using a 1-way-ANOVA with the restricted maximum likelihood estimation. The percentage of torque loss was calculated. The LIFETEST procedure was used to analyze the survival probability of the groups (α=.05). RESULTS The effect of crown height on the detorque values of screws was not found to be statistically significant (P>.05). The mean detorque value for 6-mm crowns was 23.5 Ncm, 24.4 Ncm for 10-mm crowns, and 22.1 Ncm for 14-mm crowns. A significant effect of crown height was found on the survival (P=.006), and the time-to-failure survival of 14-mm crowns was significantly lower than the survival of 6 mm and 10 mm crowns (P=.020), where no failures were observed. Four 14-mm crowns failed between the 1 and 2 million cycles after the loads were increased to 435 N. The failure modes were the same for all the crowns, implants, and screws fractured. CONCLUSIONS When the tested internal connection implant was used, the crown height did not affect the detorque values, and 14-mm crowns performed similarly to the shorter crowns in terms of torque loss after cyclic loading. However, survival of the 14-mm crown-implant complex was lower, resulting in screw and implant fractures.
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Affiliation(s)
- Burak Yilmaz
- Professor, Restorative and Prosthetic Dentistry, The Ohio State University College of Dentistry, Columbus, Ohio
| | - Diogo Gouveia
- Assistant Professor, Restorative and Prosthetic Dentistry, The Ohio State University College of Dentistry, Columbus, Ohio.
| | - Robert Seghi
- Professor Emeritus, Restorative and Prosthetic Dentistry, The Ohio State University College of Dentistry, Columbus, Ohio
| | - William Johnston
- Professor Emeritus, Restorative and Prosthetic Dentistry, The Ohio State University College of Dentistry, Columbus, Ohio
| | - Lisa A Lang
- Professor, Restorative and Prosthetic Dentistry, The Ohio State University College of Dentistry, Columbus, Ohio
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Özyurt A. Investigation of implant internal screw loosening under hyperbaric conditions: An in vitro study. Clin Implant Dent Relat Res 2021; 23:417-422. [PMID: 33817947 DOI: 10.1111/cid.12997] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 03/16/2021] [Accepted: 03/22/2021] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND PURPOSE The internal screw has an essential role in carrying abutment and prosthesis loading. Some dental implant patients such as scuba divers, mineworkers, and hyperbaric oxygen patients are exposed to hyperbaric atmospheres. The aim of this study was to investigate internal screw loosening under hyperbaric conditions. MATERIALS AND METHODS Forty-two dental implants were placed into plexiglass blocks. Abutments were fixed with internal screws by 25 Ncm torque force. Groups were set as control, 2.8-bar air pressure, and 4-bar air pressure groups. Hyperbaric groups were subdivided and exposed to either one or six cycles. Removal torque values were measured with a digital torque meter. Data were analyzed statistically using analysis of variance and Tamhane's T2 tests, considering p < 0.05 as the level of statistical significance. Internal screw threads were qualitatively observed under magnification. RESULTS Four-bar groups showed the lowest removal torque values among all groups (p < 0.001). 2.8-Bar groups did not show significant differences compared with control groups. There was no statistically significant difference between the one and six pressure cycle subgroups in each group. All internal screw threads had various deformations. CONCLUSION Four-bar air pressure had a significant effect on internal screw loosening. Internal screw tightening protocols should be reconsidered for patients exposed to advanced hyperbaric conditions.
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Affiliation(s)
- Anıl Özyurt
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Trakya University, Edirne, Turkey
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10
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Mostafavi AS, Memarian M, Seddigh MA. Effect of fluid contamination on reverse torque values in implant-abutment connections under oral conditions. J Adv Prosthodont 2021; 13:65-70. [PMID: 33747396 PMCID: PMC7943751 DOI: 10.4047/jap.2021.13.1.65] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 12/05/2020] [Accepted: 12/30/2020] [Indexed: 11/26/2022] Open
Abstract
PURPOSE Implant mechanical complications, including screw loosening, can influence dental implant success. It has been shown that torque values are affected by contamination occurred in implant-abutment (I/A) interface. This study aimed to examine the effects of blood, saliva, fluoride and chlorhexidine contamination on reverse torque values (RTVs) of abutment screws in oral conditions. MATERIALS AND METHODS 50 fixtures were mounted into the stainless-steel holders and divided into five groups (n = 10). Except control group (NC), fixture screw holes in other groups were contaminated with chlorhexidine (CG), saliva (SG), blood (BG), or fluoride (FG). Abutment screws were tightened with a digital torque meter. I/A assemblies were subjected to thermocycling and cyclic loading. The mean RTVs were recorded and data were analyzed with one-way ANOVA and Tukey test. RESULTS Except for specimens in SG (20.56 ± 1.33), other specimens in BG (21.11 ± 1.54), CG (22.89 ± 1.1) and FG (24.00 ± 1.12) displayed significantly higher RTVs compared to NC (19.00 ± 1.87). The highest RTVs were detected in CG and FG. CONCLUSION The obtained data robustly suggest that RTVs were significantly affected by fluid contaminations. Specimens in FG and CG displayed the highest RTVs. Therefore, clinicians should have enough knowledge about probable contaminations in I/A interface in order to manage them during clinical procedure and to inform patients about using oral care products.
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Affiliation(s)
- Azam Sadat Mostafavi
- Department of Prosthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Maryam Memarian
- Department of Prosthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Ali Seddigh
- Department of Prosthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
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Alsubaiy EF. Abutment screw loosening in implants: A literature review. J Family Med Prim Care 2020; 9:5490-5494. [PMID: 33532384 PMCID: PMC7842481 DOI: 10.4103/jfmpc.jfmpc_1343_20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 09/13/2020] [Accepted: 09/28/2020] [Indexed: 11/04/2022] Open
Abstract
This review was intended on major factors contributing to abutment screw loosening. A search of Pubmed and Google Scholar, as well as a manual search, was conducted. Publications and articles accepted for publication up to February 2020 were included. Out of 150 studies retrieved, a total of 57 were selected for this review. Dental implants are associated with a complexity of abutment screw loosening. Implantologists and prosthodontists should be aware of factors that contribute to this problem. In this review previously identified factors were collected, the consideration of which can help to reduce the frequency of abutment screw loosening.
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Affiliation(s)
- Ebrahim F Alsubaiy
- Assistant Professor, Department of Prosthodontics, King Khalid University, Abha, Saudi Arabia
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