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Velasco-Ortega E, Jiménez-Guerra A, Ortiz-Garcia I, Nuñez-Márquez E, Moreno-Muñoz J, Gil J, Delgado LM, Rondón-Romero JL, Monsalve-Guil L. Silver coating on dental implant-abutment connection screws as potential strategy to prevent loosening and minimizing bacteria adhesion. Front Bioeng Biotechnol 2024; 11:1293582. [PMID: 38264580 PMCID: PMC10803504 DOI: 10.3389/fbioe.2023.1293582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 12/21/2023] [Indexed: 01/25/2024] Open
Abstract
Introduction: One of the main problems for the long-term behavior of dental implants are loosening of the implant-abutment connection screws and bacterial infiltration. The aim of this work is to increase the screw fixation by silver coating, providing superior mechanical retaining and antibacterial effect. Methods: Eighty dental implants with their abutments and screws have been studied. Twenty screws were not coated and were used as a control while the rest of screws were silver coated by sputtering, with three different thickness: 10, 20 and 40 μm and 20 screws per each thickness. Coating morphology and thickness were determined by scanning electron microscopy using image analysis systems. The screws were tightened for each of the thicknesses and the control with two torques 15 Ncm and 20 Ncm and tested under mechanical fatigue simulating oral stresses up to a maximum of 500,000 cycles. The remaining torques at different cycles were determined with a high-sensitivity torquemeter. Cell viability assays were performed with SaOs-2 osteoblasts and microbiological studies were performed against Streptococcus gordonii and Enterococcus faecalis bacteria strains, determining their metabolic activity and viability using live/dead staining. Results: It was observed a decrease in torque as cycles increase. For a preload of 15 Ncm at 100,000 cycles, the loosening was complete and, for 20 Ncm at 500,000 cycles, 85% of torque was lost. The silver coatings retained the torque, especially the one with a thickness of 40 μm, retaining 90% of the initial torque at 500,000 cycles. It was observed that osteoblastic viability values did not reach 70%, which could indicate a slight cytotoxic effect in contact with cells or tissues; however, the screw should not be in direct contact with tissue or living cells. Silver coating induced a significant reduction of the bacteria metabolic activity for Streptococcus gordonii and Enterococcus faecalis, around 90% and 85% respectively. Discussion: Therefore, this coating may be of interest to prevent loosening of implant systems with a worthy antibacterial response.
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Affiliation(s)
- Eugenio Velasco-Ortega
- Comprehensive Dentistry for Adults and Gerodontology, Master in Implant Dentistry, Faculty of Dentistry, University of Seville, Seville, Spain
| | - Alvaro Jiménez-Guerra
- Comprehensive Dentistry for Adults and Gerodontology, Master in Implant Dentistry, Faculty of Dentistry, University of Seville, Seville, Spain
| | - Iván Ortiz-Garcia
- Comprehensive Dentistry for Adults and Gerodontology, Master in Implant Dentistry, Faculty of Dentistry, University of Seville, Seville, Spain
| | - Enrique Nuñez-Márquez
- Comprehensive Dentistry for Adults and Gerodontology, Master in Implant Dentistry, Faculty of Dentistry, University of Seville, Seville, Spain
| | - Jesús Moreno-Muñoz
- Comprehensive Dentistry for Adults and Gerodontology, Master in Implant Dentistry, Faculty of Dentistry, University of Seville, Seville, Spain
| | - Javier Gil
- Bioengineering Institute of Technology, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Luis M. Delgado
- Bioengineering Institute of Technology, Universitat Internacional de Catalunya, Barcelona, Spain
| | - José Luis Rondón-Romero
- Comprehensive Dentistry for Adults and Gerodontology, Master in Implant Dentistry, Faculty of Dentistry, University of Seville, Seville, Spain
| | - Loreto Monsalve-Guil
- Comprehensive Dentistry for Adults and Gerodontology, Master in Implant Dentistry, Faculty of Dentistry, University of Seville, Seville, Spain
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Lee KY, Shin KS, Jung JH, Cho HW, Kwon KH, Kim YL. Clinical study on screw loosening in dental implant prostheses: a 6-year retrospective study. J Korean Assoc Oral Maxillofac Surg 2020; 46:133-142. [PMID: 32364353 PMCID: PMC7222622 DOI: 10.5125/jkaoms.2020.46.2.133] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Revised: 10/21/2019] [Accepted: 11/08/2019] [Indexed: 11/16/2022] Open
Abstract
Objectives In this study, we determined the incidence and pattern of screw loosening in patients who received dental implants. Materials and Methods Patients who received implants between January 2008 and October 2013 and completed their prosthetic rehabilitation were evaluated for the incidence, frequency, and onset of screw loosening using dental charts and radiographs. The association between each factor and screw loosening was analyzed using the chi-square test and a multivariate analysis with binary logistic regression models (P<0.05). Results Total 1,928 implants were placed in 837 patients (448 males, 389 females), whose follow-up period after loading varied from 0.25 to 70 months (mean period, 31.5 months). Screw loosening occurred in 7.2% of implants. Most cases occurred less than six months after loading. Among those, 22.3% experienced recurrent screw loosening. Screw loosening was most common in the molar region (8.5%) and frequently associated with an implant diameter of ≥5 mm (14.2%). External implant–abutment connections (8.9%) and screw-retained implant prostheses (10.1%) showed higher incidence of problems than internal implant–abutment connections and cement-retained implants, respectively. Screw loosening was most common in implant prostheses with single crowns (14.0%). Conclusion Within the limits of the current study, we conclude that the incidence of screw loosening differs significantly according to the position of implant placement, the type of implant and manufacturer, implant diameter, the type of implant–abutment connection, the type of retention in the implant prosthesis, and the type of implant prosthesis.
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Affiliation(s)
- Ki-Young Lee
- Departments of Prosthodontics, Wonkwang University Dental Hospital, College of Dentistry, Wonkwang University, Iksan, Korea
| | - Kyung Su Shin
- Departments of Oral and Maxillofacial Surgery, Wonkwang University Dental Hospital, College of Dentistry, Wonkwang University, Iksan, Korea
| | - Ji-Hye Jung
- Departments of Prosthodontics, Wonkwang University Dental Hospital, College of Dentistry, Wonkwang University, Iksan, Korea
| | - Hye-Won Cho
- Departments of Prosthodontics, Wonkwang University Dental Hospital, College of Dentistry, Wonkwang University, Iksan, Korea
| | - Kyung-Hwan Kwon
- Departments of Oral and Maxillofacial Surgery, Wonkwang University Dental Hospital, College of Dentistry, Wonkwang University, Iksan, Korea
| | - Yu-Lee Kim
- Departments of Prosthodontics, Wonkwang University Dental Hospital, College of Dentistry, Wonkwang University, Iksan, Korea
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Liu Y, Lin Y, Di P. A modified implant abutment holder fabricated with fused deposition modeling to improve the transfer process for implant-supported restorations. J Prosthet Dent 2020; 125:411-414. [PMID: 32248997 DOI: 10.1016/j.prosdent.2020.01.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Revised: 01/05/2020] [Accepted: 01/06/2020] [Indexed: 10/24/2022]
Abstract
Ingestion or aspiration of an implant abutment can occur in patients during the process of abutment transfer for implant-supported restorations, especially in the posterior region. A technique of fabricating an abutment holder is described to prevent ingestion or aspiration by computer-aided design (CAD) and fused deposition modeling (FDM). The modified abutment holder has a serrated handle for a firm grip and a barrel-shaped fixed portion that firmly secures the abutment. The modified holder is more secure than the conventional hexagon screwdriver. Furthermore, abutment holders can be easily manufactured by using 3D printers and repeatedly used for multiple implants restoration without substitution.
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Affiliation(s)
- Yanping Liu
- PhD candidate, Department of Oral Implantology, Peking University School and Hospital of Stomatology, Beijing, PR China
| | - Ye Lin
- Professor, Department of Oral Implantology, Peking University School and Hospital of Stomatology, Beijing, PR China
| | - Ping Di
- Professor, Department of Oral Implantology, Peking University School and Hospital of Stomatology, Beijing, PR China.
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Kunrath MF, Hübler R. A bone preservation protocol that enables evaluation of osseointegration of implants with micro- and nanotextured surfaces. Biotech Histochem 2018; 94:261-270. [PMID: 30556450 DOI: 10.1080/10520295.2018.1552017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Development of surface treatments has enabled secure attachment of dental implants in less than 1 month. Consequently, it is necessary to characterize accurately the osseointegration of the implant surface in the region of the bone-implant contact (BIC). We developed a method for sample preparation that preserves both bone and BIC to permit analysis of the contact interface. We prepared eight nanotextured implants and implanted them in rabbit tibias. After healing for 30 days, outcomes were analyzed using both our bone preservation protocol and routine decalcification followed by preparation of histological sections stained by hematoxylin and eosin (H & E). Pull-out tests for implant osseointegration were performed after healing. Non-implanted samples of rabbit mandible were used as a control for assessing organic and mineralized bone characteristics and bone structure. Our bone preservation protocol enabled evaluation of many of the same bone characteristics as histological sections stained with H & E. Our protocol enables analysis of implant samples, implant surfaces and osseointegration without risk of BIC damage.
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Affiliation(s)
- M F Kunrath
- a Dentistry University , School of Health Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre , Brazil
| | - R Hübler
- b Materials and Nanoscience Laboratory , Physics University, Pontifical Catholic University of Rio Grande do Sul , Porto Alegre , Brazil
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Gupta S, Gupta H, Tandan A. Technical complications of implant-causes and management: A comprehensive review. Natl J Maxillofac Surg 2015; 6:3-8. [PMID: 26668445 PMCID: PMC4668729 DOI: 10.4103/0975-5950.168233] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Given the increasing popularity of dental implants, the number of failures due to late implant fracture is also expected to increase. Hence, the scope for prevention and management needs to be emphasized. The objective of this review article is to analyze the various causes of failure of dental implants due to implant fixture/abutment screw fractures and also to enumerate the management and the preventive options for these failures, thereby aiming to help the clinicians to properly plan the implant-supported prosthesis treatment by considering the important biomechanical aspects of this type of rehabilitation. The present review emphasizes the causes and management of technical complications and not the incidence of such complications.
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Affiliation(s)
- Swati Gupta
- Department of Prosthodontics, Babu Banarasi Das College of Dental Sciences, Lucknow, Uttar Pradesh, India
| | - Hemant Gupta
- Department of Oral and Maxillofacial Surgery, Babu Banarasi Das College of Dental Sciences, Lucknow, Uttar Pradesh, India
| | - Amrit Tandan
- Department of Prosthodontics, Babu Banarasi Das College of Dental Sciences, Lucknow, Uttar Pradesh, India
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Karimi MR, Fathi S, Ghanavati F. Effects of counter torque and transposition (transfer) of installed implants timing on their integration in dog tibia. J Adv Prosthodont 2015; 7:62-8. [PMID: 25722840 PMCID: PMC4341189 DOI: 10.4047/jap.2015.7.1.62] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 10/27/2014] [Accepted: 11/07/2014] [Indexed: 11/12/2022] Open
Abstract
PURPOSE The purpose of this research was to evaluate the amount of reosseointegration after counter torquing (reverse torque) and transposing the installed implants at different times. MATERIALS AND METHODS This study was done on ten tibiae of five cross-bred dogs. At the first day one implant was installed in each tibia. After one week half of the implants were randomly counter torqued (1WCT) and the other half were explanted and reimplanted in a new juxtaposition site (transposed)(1WT). At the same time three new implants were installed in each dog, one of them was considered as one week control (1WC) and remaining two as 8 week groups (8WCT&8WT). After eight weeks the 1WCT and 1WT implants were loosened by counter torque and the quantity of needed force for liberation was measured with the digital device (BGI). At the same time one implant was installed in each dog as eight week control (8WC) and the same protocol was repeated for 8 week groups after another 8 weeks. RESULTS All implants were osseointegrated. Mean quantities of osseointegration in case groups indicated better amounts rather than control groups. CONCLUSION Counter torque or transposition of the installed implants one week or eight weeks after the implantation did lead to osseointegration.
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Affiliation(s)
- Mohammad Reza Karimi
- Department of Periodontics, Dental Branch, Islamic Azad University, Tehran, Iran
| | - Shima Fathi
- Postgraduate of Oral Medicine, Dental Branch, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Farzin Ghanavati
- Department of Periodontics, Dental Research Center, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Lalithamma JJ, Mallan SA, Murukan PA, Zarina R. A comparative study on microgap of premade abutments and abutments cast in base metal alloys. J ORAL IMPLANTOL 2014; 40:239-49. [PMID: 24914909 DOI: 10.1563/aaid-joi-d-11-00163] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The study compared the marginal accuracy of premade and cast abutments. Premade titanium, stainless steel, and gold abutments formed the control groups. Plastic abutments were cast in nickel-chromium, cobalt-chromium and grade IV titanium. The abutment/implant interface was analyzed. Analysis of variance and Duncan's multiple range test revealed no significant difference in mean marginal microgap between premade gold and titanium abutments and between premade stainless steel and cast titanium abutments. Statistically significant differences (P < .001) were found among all other groups.
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Affiliation(s)
- Jaini Jaini Lalithamma
- 1 Department of Prosthodontics, Educare Institute of Dental Sciences, Malappuram, Kerala, India
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Yoon TH, Chaimattayompol N. A simple technique to fabricate an implant counter torque device. J Prosthet Dent 2012; 107:411-2. [PMID: 22633599 DOI: 10.1016/s0022-3913(12)60101-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Tae-Ho Yoon
- Department of Prosthodontics and Operative Dentistry, School of Dental Medicine, Tufts University, Boston, MA, USA.
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Effect of using a titanium washer on the removal torque of an abutment screw in the external connection type of dental implant. IMPLANT DENT 2012; 21:156-9. [PMID: 22391862 DOI: 10.1097/id.0b013e31824a02b9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE The aim of this study was to determine the effect of using a washer on the removal torque of an abutment screw in the external connection type of dental implant and abutment complex. MATERIALS AND METHODS Four experimental groups with titanium washers of different types (CP titanium or Ti6Al4V titanium alloy) and thicknesses (1.0 or 2.0 mm) included between the abutment and external connection type of implant were investigated. No washer was applied in the control group. The removal torque was measured with a resolution of 0.1 Ncm. One-way analysis of variance (α = 0.05) and Scheffé's post hoc test were used for statistical analysis. RESULTS The removal torque was higher in all the groups with a washer than in the control group (α = 0.05), higher with a CP titanium washer than with a titanium alloy washer of the same thickness, and higher with a 2.0-mm-thick washer than with a 1.0-mm-thick washer (α = 0.05). CONCLUSIONS Inclusion of a washer between the titanium screw and the abutment seems to increase the removal torque. A 2.0-mm-thick CP titanium washer might provide the largest increase in the removal torque.
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Assunção WG, Barão VAR, Delben JA, Gomes ÉA, Garcia IR. Effect of unilateral misfit on preload of retention screws of implant-supported prostheses submitted to mechanical cycling. J Prosthodont Res 2010; 55:12-8. [PMID: 20627771 DOI: 10.1016/j.jpor.2010.05.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Revised: 03/14/2010] [Accepted: 05/12/2010] [Indexed: 11/19/2022]
Abstract
PURPOSE The aim of this study was to evaluate the effect of different levels of unilateral angular misfit on preload maintenance of retention screws of single implant-supported prostheses submitted to mechanical cycling. MATERIALS AND METHODS Premachined UCLA abutments were cast with cobalt-chromium alloy to obtain 48 crowns divided into four groups (n=12). The crowns presented no misfit in Group A (control group) and unilateral misfits of 50 μm, 100 μm and 200 μm in the groups B, C and D, respectively. The crowns were attached to external hexagon implants with a titanium retention screw with torque of 30 N/cm. Oblique loading of 130 N at 2 Hz was applied on each replica, totalizing 5×10⁴ and 1×10⁶ cycles. Detorque values were measured initially and after each cycling period. Data were evaluated by analysis of variance and Tukey's HSD test (p<0.05). RESULTS All groups presented reduced initial detorque values (p<0.05) in comparison to the insertion torque (30±0.5 N/cm) and Group A (25.18 N/cm) exhibited the lowest reduction. After mechanical cycling, all groups presented detorque values from 19.5 N/cm to 22.38 N/cm and the mechanical cycling did not statistically influence the detorque values regardless the misfit level of the replicas. CONCLUSION The unilateral misfit influenced the preload maintenance only before mechanical cycling. The mechanical cycling did not influence the torque reduction.
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Affiliation(s)
- Wirley Gonçalves Assunção
- Department of Dental Materials and Prosthodontics, Araçatuba Dental School, Univ Estadual Paulista (UNESP), José Bonifácio, 1193, São Paulo 16015-050, Brazil.
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Moriya K, Maruo Y, Minagi S. Does rotational strain at screw tightening affect the attainment or maintenance of osseointegration? Clin Oral Implants Res 2006; 17:451-8. [PMID: 16907778 DOI: 10.1111/j.1600-0501.2005.01243.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVES This study investigated whether rotational strain affects osseointegration. MATERIAL AND METHODS A total of 135 male rats were divided into five groups: 2-w rotation, 4-w rotation, 8-w rotation, 12-w rotation and control. Two hundred and seventy implants were inserted in rat tibia. The control group received no strain, while the 2-w, 4-w, 8-w and 12-w rotation groups received rotational strain at 2, 4, 8 and 12 weeks after implant placement, respectively. Removal torque (N cm) was measured in vivo. Bone contact rate (%) was calculated histomorphologically. Immunostaining for osteonectin (ON), osteopontin (OPN) and osteocalcin (OCN) was performed. The removal torque and bone contact rate were analyzed using one-way analyses of variance and the Scheffé method. RESULTS At 4 weeks, the torque was significantly higher in the 2-w rotation group (1.30+/-0.44 N cm) than in the control group (0.79+/-0.67 N cm). From 8 to 16 weeks, the strained groups showed no significant differences from the control group. From the bone contact rates, bone formation was larger in the 4-week rotation group (62.9+/-10.7%) than in the control group (42.1+/-17.9%) at 8 weeks. The 4-week rotation group showed higher bone contact rate (61.1+/-11.3%) compared with the other strained groups and maintained this higher value until 16 weeks, showing no significant difference from the control group (72+/-5.2%). At the implant-bone interface, OPN was widely distributed and OCN was detected at a low level; however, ON could not be observed in any group. CONCLUSIONS The bone contact rate changed when rotational strain was exerted at different periods after implant placement. However, the removal torque and distribution of extracellular matrix proteins were not adversely affected by the rotational strain.
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Affiliation(s)
- Katsunori Moriya
- Department of Occlusal and Oral Functional Rehabilitation, Okayama City, Japan.
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Ozcelik TB, Ozcelik O. An alternative technique for fabricating a single-implant-supported crown. J Prosthet Dent 2005; 94:571-2. [PMID: 16316807 DOI: 10.1016/j.prosdent.2005.07.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Hanses G, Smedberg JI, Nilner K. Analysis of a device for assessment of abutment and prosthesis screw loosening in oral implants. Clin Oral Implants Res 2002; 13:666-70. [PMID: 12519343 DOI: 10.1034/j.1600-0501.2002.130614.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Screw loosening is an irritating problem in implant dentistry. Loosened abutment screws and prosthesis screws are often found at yearly examinations. Loosened screws may cause costly complications, such as screw fractures and fracture of the framework, and methods to prevent them would be welcome. The purpose of this study is firstly to describe a mechanical protractor device designed to fit the electrical Torque Controller (Nobel Biocare, DEA 020, Gothenburg, Sweden) and measure the number of degrees necessary to retighten the abutment screw or the prosthesis screw to reach the target torque value. A second purpose is to analyse the precision and validity of the device. The results of the study indicate that the degree of preset loosening of abutment and prosthesis screws can be well reflected in the number of degrees necessary for retightening. It was also shown that it is possible to retighten the abutment and prosthesis screws with a precision of 1.7 degrees and 1.3 degrees, respectively. The study shows that the device has good precision and validity. By using this device, we hope to be able to evaluate various parameters for screw stability, such as the type of implant system, the number of fixtures, the type of abutments, the type of bridge material and the need for retightening of the abutment and prosthesis screws.
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Affiliation(s)
- Gunnel Hanses
- Department of of Prosthetic Dentistry, St Erik's Hospital, Public Dental Service, Stockholm, Sweden
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Lang LA, Wang RF, May KB. The influence of abutment screw tightening on screw joint configuration. J Prosthet Dent 2002; 87:74-9. [PMID: 11807487 DOI: 10.1067/mpr.2002.121488] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
STATEMENT OF PROBLEM Limiting abutment-to-implant hexagonal discrepancies and rotational movement of the abutment around the implant to less than 5 degrees would result in a more stable screw joint. However, the exact relationship after abutment screw tightening is unknown, as is the effect of a counter-torque device in limiting abutment movement during screw tightening. PURPOSE This study examined the orientation of the abutment hexagon to the implant hexagon after tightening of the abutment screw for several abutment systems with and without the use of a counter-torque device. MATERIAL AND METHODS Thirty conical self-tapping implants (3.75 x 10.0 mm) and 10 wide-platform Brånemark System implants (5.0 x 10.0 mm), along with 10 abutment specimens from the CeraOne, Estheticone, Procera, and AuraAdapt systems, were selected for this investigation. The implants were placed in a holding device prior to tightening of the abutments. When the tightening torque recommended for each abutment system was reached with the use of a torque controller, each implant abutment specimen was removed from the holding device and embedded in a hard resin medium. The specimens were sectioned in a horizontal direction at the level of the hexagons and cleansed of debris prior to examination. The hexagon orientations were assessed as the degree and direction of rotation of the abutment hexagon around the implant hexagon. RESULTS The range of the maximum degrees of rotation for all 4 abutment groups tightened with or without the counter-torque device was slightly more than 3.53 degrees. The absolute degrees of rotation for all 4 abutment groups were less than 1.50 degrees with or without the use of the counter-torque device. CONCLUSION The hexagon-to-hexagon orientation measured as rotational fit on all abutment systems was below the 5 degrees suggested as optimal for screw joint stability. The absolute degrees of rotation for all 4 abutment groups were less than 1.50 degrees regardless of whether the counter-torque device was used.
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Affiliation(s)
- Lisa A Lang
- Department of Restorative Dentistry, Division of Prosthodontics, School of Dentistry, University of Colorado, Denver Health Sciences Center, 80262, USA.
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