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de Freitas JR, Valente MLDC, Brazão EH, Moris ICM, Bruniera JFB, Silva-Sousa YTC, Alfredo E. Evaluation of axial displacement and torque loss of Morse-type prosthetic abutments of different angular tapers to their respective implants. J Prosthet Dent 2024:S0022-3913(24)00571-7. [PMID: 39261220 DOI: 10.1016/j.prosdent.2024.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 08/12/2024] [Accepted: 08/15/2024] [Indexed: 09/13/2024]
Abstract
STATEMENT OF PROBLEM The biomechanical stability of the implant-prosthesis assembly and its maintenance under function is a determining factor in the success of implant prosthesis rehabilitation, but studies of different angular tapers are lacking. PURPOSE The purpose of this in vitro study was to evaluate the axial displacement and torque loss of prosthetic abutments with Morse-type connections of different angular tapers after thermomechanical cycling by using microcomputed tomography (µCT) and a digital torque wrench. MATERIAL AND METHODS Eighteen Ø3.5×11.5-mm implants were embedded in polyvinyl chloride cylinders, and the 3 different types of abutments (n=6) with angular tapers of 11.5 degrees - Alvim Cone Morse (ACM-11.5), 16.0 degrees - Helix Gran Morse (HGM-16), and 24.0 degrees - Nobel Replace Conical Connection (NRC-24) were installed with the torque recommended by the manufacturers. To calculate the axial displacements of the abutments about the implants, zirconia maxillary canine crowns were fabricated using a computer-aided design and computer-aided manufacturing (CAD-CAM) system and cemented onto the abutments. Before and after thermomechanical cycling, the assemblies were scanned using microtomography (micro-CT) to assess axial displacement, and the torque losses were calculated after the abutments were finally unscrewed. A load of 100 N, frequency of 2 Hz, and 106 cycles with temperature variation of 5 °C to 55 °C were used for the thermomechanical cycling. Analysis of variance and the Tukey post hoc test (α=.05) were used for analysis. RESULTS A significant difference was observed between the abutments for axial displacement, measured after thermomechanical cycling (P=.002). The ACM-11.5 abutment showed the highest mean value (134.1 ±58.7 µm), different from HGM-16 (63.3 ±26.1 µm) (P=.013) and NRC-24 (42.7 ±8.7 µm) (P=.002); the 2 latter groups were similar to each other (P=.618). For the torque losses, no significant difference was found among the abutments (P=.928), but there were significant differences for the thermomechanical cycling (before and after) (P<.001) in that the loss of torque was greater after thermocycling. CONCLUSIONS The smaller the taper angle of the Morse-type prosthetic abutment, the greater its axial displacement, and the thermomechanical cycling significantly reduced pretorque, regardless of taper.
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Affiliation(s)
- José Roberto de Freitas
- Professor, School of Dentistry, University of Ribeirão Preto (UNAERP), Ribeirão Preto, Brazil
| | | | - Elisabeth Helena Brazão
- Doctoral student, School of Dentistry, University of Ribeirão Preto (UNAERP), Ribeirão Preto, Brazil
| | | | | | | | - Edson Alfredo
- Professor, School of Dentistry, University of Ribeirão Preto (UNAERP), Ribeirão Preto, Brazil.
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Zhong P, Deng L, Xu S, Cao Y. Effect of polishing process on torque loss ratio and microgap of selective laser melting abutment: an in vitro study. BMC Oral Health 2024; 24:1055. [PMID: 39251975 PMCID: PMC11386349 DOI: 10.1186/s12903-024-04829-y] [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: 05/02/2024] [Accepted: 08/28/2024] [Indexed: 09/11/2024] Open
Abstract
BACKGROUND The purpose of this in vitro study was to investigate the effect of polishing post-treatment process on the torque loss ratio and microgap of Selective Laser Melting (SLM) abutments before and after mechanical cycling test through improving the surface roughness of the implant-abutment interface. MATERIALS AND METHODS Forty SLM abutments were fabricated, with 20 underwent minor back-cutting, designated as polishing, in the implant-abutment interface. The abutments were divided into three groups: SLM abutments (group A), original abutments (group B), and polished SLM abutments (group C), each containing 20 abutments. Surface roughness was evaluated using a laser microscope. Implant-abutment specimens were subjected to mechanical cycling test, and disassembly torque values were measured before and after. Scanning electron microscope (SEM) was used to measure microgap after longitudinal sectioning of specimens. Correlation between surface roughness, torque loss ratio, and microgap were evaluated. LSD's test and Tamhane's T2 comparison were used to analyze the data (α = 0.05). RESULTS The Sz value of polished SLM abutments (6.86 ± 0.64 μm) demonstrated a significant reduction compared to SLM abutments (26.52 ± 7.12 μm). The torque loss ratio of polished SLM abutments (24.16%) was significantly lower than SLM abutments (58.26%), while no statistically significant difference that original abutments (18.23%). The implant-abutment microgap of polished SLM abutments (2.38 ± 1.39 μm) was significantly lower than SLM abutments (8.69 ± 5.30 μm), and this difference was not statistically significant with original abutments (1.87 ± 0.81 μm). A significant positive correlation was identified between Sz values and the ratio of torque loss after cycling test (r = 0.903, P < 0.01), as well as Sz values and the microgap for all specimens in SLM abutments and polished SLM abutments (r = 0.800, P < 0.01). CONCLUSION The findings of this study indicated that the polishing step of minor back-cutting can lead to a notable improvement in the roughness of SLM abutments interface, which subsequently optimized the implant-abutment fit. It can be seen that the application of minor back-cutting method has advanced the clinical use of SLM abutments.
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Affiliation(s)
- Peixing Zhong
- Department of Prosthetics, Guangxi Medical University College of Stomatology, 6 Shuangyong Road, Nanning, 530021, Guangxi, PR China
| | - Limei Deng
- Department of Oral and Maxillofacial Surgery, The People's Hospital of Guangxi Zhuang Autonomous Region, 6 Taoyuan Road, Nanning, 530021, Guangxi, PR China
| | - Sheng Xu
- Department of Prosthetics, Guangxi Medical University College of Stomatology, 6 Shuangyong Road, Nanning, 530021, Guangxi, PR China
| | - Yong Cao
- Department of Oral and Maxillofacial Surgery, The People's Hospital of Guangxi Zhuang Autonomous Region, 6 Taoyuan Road, Nanning, 530021, Guangxi, PR China.
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Lenz U, Santos RB, Griggs JA, Estrela C, Bueno MDR, Porto OCL, Della Bona A. Longevity of different abutments placed on narrow diameter implants: Assessment of structural damage and loosening. Dent Mater 2024; 40:1332-1340. [PMID: 38876825 DOI: 10.1016/j.dental.2024.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 05/29/2024] [Accepted: 06/03/2024] [Indexed: 06/16/2024]
Abstract
OBJECTIVES To evaluate structural damage and loosening of abutments placed on narrow diameter implants after cyclic fatigue. METHODS Sixty Morse taper narrow diameter implants (Neodent, Brazil) received two types of abutments (1PA- one-piece abutment or 2PA- two-piece abutment), which were randomly divided into 3 fatigue experiments (n = 10). The implants were placed into a customized supporting holder and a software-assisted digital torque wrench secured the manufacturer recommended torque for each abutment. Cone beam computed tomography (CBCT) scans were acquired, before and after fatigue, and post-processed (software e-Vol DX) to assess damage and abutment displacement. The boundary fatigue method was adapted to use 2 × 106 cycles, 2 Hz of frequency and constant peak load of 80 N (first experiment) that varied according to the failure rate of previous specimens (second and third experiments). Failure was evaluated using CBCT scans and removal torque values. Data were used to estimate long-term torque degradation, probability of failure and Weibull modulus (software ALTA PRO9). RESULTS All 2PA specimens became loosen independently of the applied fatigue load, and structural bending was observed in 14 abutments. Eight 1PA got loosen during the fatigue experiment. The Weibull analysis showed a lower modulus (m = 1.0; 0.7, 1.4) for 1PA than for 2PA (m = 2.6; 2, 3.4) resulting in longer predicted lifetimes and slower torque degradation for 1PA than for 2PA specimens. SIGNIFICANCE 1PA showed greater long-term survival probability than 2PA. Predicting the lifetime and mechanical behavior of implant-abutment systems are useful information to clinicians during the decision-making process of oral rehabilitations.
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Affiliation(s)
- Ulysses Lenz
- Postgraduate Program in Dentistry, School of Dentistry, University of Passo Fundo, Passo Fundo, RS, Brazil
| | - Renan Brandenburg Santos
- Postgraduate Program in Dentistry, School of Dentistry, University of Passo Fundo, Passo Fundo, RS, Brazil
| | - Jason Alan Griggs
- Department of Biomedical Materials Science, University of Mississippi Medical Center, MS, USA
| | - Carlos Estrela
- School of Dentistry, Federal University of Goiás, Goiânia, GO, Brazil
| | | | | | - Alvaro Della Bona
- Postgraduate Program in Dentistry, School of Dentistry, University of Passo Fundo, Passo Fundo, RS, Brazil.
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Hendi A, Mirzaee S, Falahchai M. The effect of different implant-abutment types and heights on screw loosening in cases with increased crown height space. Clin Exp Dent Res 2024; 10:e894. [PMID: 38881218 PMCID: PMC11180708 DOI: 10.1002/cre2.894] [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: 02/05/2024] [Revised: 04/13/2024] [Accepted: 04/23/2024] [Indexed: 06/18/2024] Open
Abstract
OBJECTIVES The stability of the abutment screw is pivotal for successful implant-supported restorations, yet screw loosening remains a common complication, leading to compromised function and potential implant failure. This study aims to evaluate the effect of different implant-abutment types and heights on screw loosening in cases with increased crown height space (CHS). MATERIALS AND METHODS In this in vitro study, a total of 64 abutments in eight distinct groups based on their type and height were evaluated. These groups included stock, cast, and milled abutments with heights of 4 mm (groups S4, C4, and M4), 7 mm (groups S7, C7, and M7), and 10 mm (groups C10 and M10). Removal torque loss (RTL) was assessed both before and after subjecting the abutments to dynamic cyclic loading. Additionally, the differences between initial RTL and RTL following cyclic loading were analyzed for each group (p < .05). RESULTS The C10 group demonstrated the highest RTL, whereas the S4 group exhibited the lowest initial RTL percentage (p < .05). Furthermore, the study established significant variations in RTL percentages and the discrepancies between initial and postcyclic loading RTL across different abutment groups (p < .05). Additionally, both abutment types and heights were found to significantly influence the RTL percentage (p < .05). CONCLUSION The type and height of the implant abutment affected screw loosening, and in an increased CHS of 12 mm, using a stock abutment with a postheight of 4 mm can be effective in minimizing screw loosening.
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Affiliation(s)
- Amirreza Hendi
- Department of Prosthodontics, School of Dentistry, Dental Sciences Research CenterGuilan University of Medical SciencesRashtIran
| | - Sobhan Mirzaee
- School of Dentistry, Dental Sciences Research CenterGuilan University of Medical SciencesRashtIran
| | - Mehran Falahchai
- Department of Prosthodontics, School of Dentistry, Dental Sciences Research CenterGuilan University of Medical SciencesRashtIran
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Sun M, Shui Y, Zhang Y, Ma R, Zhao Y, Chen H, Yu P, Li Z, Wu T, Yu H. Influence of Abutment Screw-Tightening Methods on the Screw Joint: Immediate and Long-Term Stability. Int J Dent 2024; 2024:5768318. [PMID: 38264680 PMCID: PMC10805556 DOI: 10.1155/2024/5768318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 12/12/2023] [Accepted: 12/20/2023] [Indexed: 01/25/2024] Open
Abstract
Objective To evaluate the influence of screw-tightening methods on the immediate and long-term stability of dental implant screw joints. Methodology. A total of 150 implants of three different implant systems with different diameters were used in this study. Each group was divided into three subgroups (n = 5), according to the tightening methods (A-tightening with recommended torque and retorque after 10 min; B-tightening with recommended torque, then loosening and immediate retorque; C-tightening with recommended torque only once). The operating time of tightening the assemblies was recorded. Ten minutes later, the immediate removal torque (IRT) (Ncm) was measured. After retightening the assemblies, a dynamic load between 20 and 200 N was applied for 105 cycles, and the postloading removal torque (PRT) (Ncm) was measured. Scanning electron microscopy (SEM) was used to observe the surface topography of the screws. Results For different types of implants, the IRTs were 11.92 ± 1.04-34.12 ± 0.36 Ncm for method A, 11.64 ± 0.57-33.96 ± 0.29 Ncm for method B, and 10.30 ± 0.41-31.62 ± 0.52 Ncm for method C, and the IRTs of methods A and B were 6.28%-21.58% higher than that of method C (P ≤ 0.046). The PRTs were 4.08 ± 0.77-29.86 ± 0.65 Ncm for method A, 4.04 ± 0.40-29.60 ± 0.36 Ncm for method B, and 2.98 ± 0.26-26.38 ± 0.59 Ncm for method C, and the PRTs of methods A and B were 11.77%-44.87% higher than that of method C (P ≤ 0.016). The removal torque loss rates of methods A (12.49% ± 0.99%-65.88% ± 4.83%) and B (12.84% ± 0.96%-65.35% ± 1.95%) were 3.04%-7.74% lower than that of method C (16.58% ± 0.56%-71.10% ± 1.58%) (P ≤ 0.017). The operating time of method A was much longer than those of methods B and C (P < 0.001). The structural integrity disruption of the screw thread was observed according to the SEM results in all postloading groups. Conclusions Method B (torquing and then loosening and immediate retorquing) increases the screw joint immediate stability by 6.28%-21.58% and the long-term stability by 11.77%-44.87% compared with method C (torquing only once), has comparable screw joint stability compared with method A (retorquing after 10 min), saves time and is recommended in clinical settings.
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Affiliation(s)
- Manlin Sun
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases and Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yusen Shui
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases and Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yuqiang Zhang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases and Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Ruiyang Ma
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases and Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yuwei Zhao
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases and Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Hongyu Chen
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases and Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Ping Yu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases and Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Zhi Li
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases and Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Tingting Wu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases and Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Haiyang Yu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases and Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
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Bhumpattarachai S, Kan JYK, Goodacre CJ, Swamidass RS, Al-Ardah A, Rungcharassaeng K, Lozada J. Effects of cyclic loading on loss of abutment screw torque of angled screw channel single implant crowns on narrow diameter implants. J Prosthet Dent 2023; 130:741.e1-741.e9. [PMID: 37689572 DOI: 10.1016/j.prosdent.2023.08.004] [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: 01/26/2023] [Revised: 08/01/2023] [Accepted: 08/02/2023] [Indexed: 09/11/2023]
Abstract
STATEMENT OF PROBLEM Screw access channels that emerge on the facial aspect of anterior screw-retained implant crowns can compromise esthetics. Recently, angled screw channels (ASCs) have been developed that can alter screw access channel angulations to improve esthetics. While ASCs can be used on narrow-diameter implants, information is limited on the loss of abutment screw torque on narrow-diameter implants with ASCs. PURPOSE The purpose of this in vitro study was to compare the loss of abutment screw torque after thermocycling and the cyclic loading of ASCs from 3 different companies connected to narrow-diameter implants. MATERIAL AND METHODS A total of 40 narrow-diameter implants (NobelReplace Conical Connection 3.5×11.5 mm) were mounted individually in acrylic resin blocks and divided equally into 4 groups. The first group, NB-0 (Control), consisted of screw-retained zirconia crowns fabricated on ASCs at 0-degree angulation (n=10). The other 3 groups consisted of a total of 30 screw-retained zirconia crowns fabricated on ASCs at 20-degree angulation: NB-20 (Angulated Screw Channel Solutions), ATL-20 (Atlantis Custom Base Solution with angulated screw access), and DA-20 (Dynamic TiBase). Each crown was secured on the mounted implant with its corresponding titanium base insert and screw and then tightened to the manufacturer's recommended torque with a digital torque gauge. The initial reverse torque value (RTVI) was obtained and recorded at baseline. Subsequently, a new set of screws were tightened to recommended values, and each specimen underwent thermocycling and then cyclic loading at 0 to 100 N at 10 Hz for 1 million cycles to simulate 1year of functional loading. After cyclic loading, the final reverse torque values (RTVF) were recorded and compared with the RTVI to evaluate the percentage torque loss (PTLF). Statistical analysis was performed using the Kruskal-Wallis analysis, Rank base analysis of covariance (ANCOVA), and the Tukey HSD post hoc comparisons (α=.05). RESULTS Significant differences were found for the PTLF among all groups after cyclic loading (P<.001). The PTLF in ATL-20 (51.4%) was significantly higher than in NB-0 (22.2%) (P<.001) and NB-20 (29.2%) (P=.010). No significant difference was found in the PTLF among other groups (P>.05). CONCLUSIONS The abutment screw torque loss after cyclic loading of the ASCs on narrow diameter implants among the 4 groups did not perform comparably. The largest percentage torque loss was recorded for the ATL-20 group. The NB-20 group demonstrated the lowest percentage torque loss. DA-20 showed percentage torque loss less than ATL-20; however, its RTVF was the lowest.
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Affiliation(s)
- Sasiya Bhumpattarachai
- Assistant Professor, Department of General Dentistry, School of Dentistry, Loma Linda University, Loma Linda, Calif; Research Associate, Advanced Dental Education Program in Implant Dentistry, School of Dentistry, Loma Linda University, Loma Linda, Calif.
| | - Joseph Y K Kan
- Professor, Advanced Dental Education Program in Implant Dentistry, School of Dentistry, Loma Linda University, Loma Linda, Calif
| | - Charles J Goodacre
- Distinguished Professor, Advanced Dental Education Program in Implant Dentistry, School of Dentistry, Loma Linda University, Loma Linda, Calif
| | - Rajesh S Swamidass
- Assistant Clinical Professor, Advanced Dental Education Program in Implant Dentistry, School of Dentistry, Loma Linda University, Loma Linda, Calif
| | - Aladdin Al-Ardah
- Associate Professor, Advanced Dental Education Program in Implant Dentistry, School of Dentistry, Loma Linda University, Loma Linda, Calif
| | | | - Jaime Lozada
- Professor and Program Director, Advanced Education Program in Implant Dentistry, School of Dentistry, Loma Linda University, Loma Linda, Calif
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Bekhit SS, Abdelhamid AM, Metwally NA. Evaluation of prosthetic screw loosening in all-on-four implant-supported restorations with two different connection systems. J Prosthet Dent 2023:S0022-3913(23)00366-9. [PMID: 37414597 DOI: 10.1016/j.prosdent.2023.05.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 05/17/2023] [Accepted: 05/18/2023] [Indexed: 07/08/2023]
Abstract
STATEMENT OF PROBLEM: The OT BRIDGE connection system can be an alternative to multiunit abutments (MUA) for patients with all-on-four implant-supported restorations. However, the amount of prosthetic screw loosening of the OT BRIDGE in comparison with the MUA used in all-on-four implant restorations is unclear. PURPOSE The purpose of this in vitro study was to compare the loss of removal torque in the absence of load and after dynamic cyclic loading between the 2 different connection systems: OT BRIDGE attachment and MUA used in all-on-four implant-supported restorations. MATERIAL AND METHODS Four dummy implants (Neobiotech Co Ltd) were inserted into an edentulous mandibular model according to the all-on-four concept. Sixteen screw-retained restorations were digitally fabricated and assigned to 2 groups: the OT BRIDGE group received 8 restorations connected with OT BRIDGE (Rhein 83 srl); the MUA group received 8 restorations connected with MUA (Neobiotech Co Ltd). Restorations were tightened to the abutments according to the manufacturers' recommendations by using a digital torque gauge. The removal torque value (RTV) was measured with the same digital torque gauge. After retightening, dynamic cyclic loading was applied by using a pneumatic custom cyclic loading machine. RTV after loading was measured with the same torque gauge. From the RTVs measured, the ratios of removal torque loss (RTL) before and after loading and the difference between before and after loading were calculated. Data were analyzed by using the independent samples t test, paired samples t test, and mixed model analysis of variance (α=.05). RESULTS The OT BRIDGE showed significantly higher RTL before loading ratio (%) than the MUA in anterior abutments (P=.002) and posterior abutments (P=.003), as well as significantly higher RTL after loading ratio (%) in anterior abutments (P=.02). The MUA showed significantly higher RTL difference between before and after loading ratio (%) than the OT BRIDGE in both anterior (P=.001) and posterior abutments (P<.001). In both systems, posterior abutments showed significantly higher RTL after loading ratio (%) than anterior abutments (P<.001). CONCLUSIONS Posterior abutments showed more prosthetic screw loosening than anterior ones in both systems. The OT BRIDGE showed higher total prosthetic screw loosening than the MUA, although this was not significant in posterior abutments after loading. However, the OT BRIDGE was less affected by cyclic loading than the MUA.
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Affiliation(s)
- Samuel Sami Bekhit
- Instructor, Department of Prosthodontics, Faculty of Dentistry, Alexandria University, Alexandria, Egypt.
| | - Ahmed M Abdelhamid
- Professor, Department of Prosthodontics, Faculty of Dentistry, Alexandria University, Alexandria, Egypt
| | - Nayrouz Adel Metwally
- Lecturer, Department of Prosthodontics, Faculty of Dentistry, Alexandria University, Alexandria, Egypt
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Varshney N, Kusum CK, Trivedi A, Kaushik M, Dubey P, Bali Y. Comparative evaluation of biological, mechanical, and patient-reported outcomes of angulated screw channel abutments versus multi-unit abutment-retained single-unit implant restorations in the anterior esthetic zone: An- in vivo study. J Indian Prosthodont Soc 2023; 23:244-252. [PMID: 37929363 PMCID: PMC10467320 DOI: 10.4103/jips.jips_101_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 06/15/2023] [Accepted: 06/16/2023] [Indexed: 11/07/2023] Open
Abstract
Aims The study aimed to evaluate biological, mechanical, and patient reported parameters associated with ASC abutments and MU abutments for the fabrication of screw retained implant crowns in the anterior esthetic zone. Setting and Design For the study, 20 patients were selected and implants were placed within the constraints of prosthetic envelope. Later, the screw retained crown was fabricated. Materials and Methods Biological parameters (including implant survival rate, marginal bone levels using cone beam computed tomography, and soft tissue assessment using periodontal indices) were measured at the time of crown placement and 1 year follow up. Mechanical parameter (screw loosening) was calculated using removal torque loss (RTL) values obtained at the time of crown placement and 1 year follow up. Patient reported parameters were evaluated using a questionnaire at 1 year follow up. Statistical Analysis Used All data were tabulated, statistically analyzed, and compared using SPSS version 23 IBM Corporation, Armonk, NY, USA. Results Implant survival was found 100% in both the groups. The marginal bone level reduced considerably in both the groups from baseline to 1 year follow up. The MU abutment group had slightly less marginal bone loss than the ASC abutment group. Additionally, there was no statistically significant difference between the two groups' periodontal indices at baseline and 1-year follow-up values. At baseline, the RTL value was substantially lower (P <0.003) in the ASC abutment group than in the MU abutment group, however at the 1-year follow-up, there was no statistically significant difference in RTL or screw loosening between the two groups. Patient-reported data showed no statistically significant difference. Conclusion Within the constraints of this study, it was suggested that both ASC and MU abutments provide equally promising results in terms of biological, mechanical, and patient-reported parameters in the anterior esthetic region for single screw-retained crowns.
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Affiliation(s)
- Niyati Varshney
- Department of Prosthodontics and Crown and Bridge, Subharti Dental College and Hospital, Swami Vivekanand Subharti University, Meerut, Uttar Pradesh, India
| | - Chandan Kumar Kusum
- Department of Prosthodontics and Crown and Bridge, Subharti Dental College and Hospital, Swami Vivekanand Subharti University, Meerut, Uttar Pradesh, India
| | - Anshul Trivedi
- Department of Prosthodontics and Crown and Bridge, Subharti Dental College and Hospital, Swami Vivekanand Subharti University, Meerut, Uttar Pradesh, India
| | - Mayur Kaushik
- Department of Periodontology, Subharti Dental College and Hospital, Swami Vivekanand Subharti University, Meerut, Uttar Pradesh, India
| | - Prajesh Dubey
- Department of Oral and Maxillofacial Surgery, Subharti Dental College and Hospital, Swami Vivekanand Subharti University, Meerut, Uttar Pradesh, India
| | - Yashika Bali
- Department of Prosthodontics and Crown and Bridge, Subharti Dental College and Hospital, Swami Vivekanand Subharti University, Meerut, Uttar Pradesh, India
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Sagheb K, Görgen CI, Döll S, Schmidtmann I, Wentaschek S. Preload and friction in an implant-abutment-screw complex including a carbon-coated titanium alloy abutment screw: an in vitro study. Int J Implant Dent 2023; 9:8. [PMID: 36947262 PMCID: PMC10033796 DOI: 10.1186/s40729-023-00473-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 03/13/2023] [Indexed: 03/23/2023] Open
Abstract
PURPOSE An experimental approach was designed to measure the preload force, the coefficient of friction and the component of the tightening torque that is needed to surmount the thread-friction in an implant-abutment-screw complex that includes a carbon-coated screw. With the determined preload values the coefficient of friction was calculated. METHODS 25 unused complexes, containing an implant, an abutment and a carbon-coated titanium alloy abutment screw, were tested. A custom load frame with two load cells and associated electronics was used. The threads were not lubricated. All abutment screws were torqued ten times to 25 Ncm. The produced preload values and a force that was proportional to the thread-friction component of the tightening torque were recorded. RESULTS Mean preload values decreased significantly with the number of repetitions (p < 0.0001) from initially 329.9 N ± 33.3 (range 255.7 to 383.9) to 253.7 N ± 36.8 (range 200.1 to 332.5) for the last tightening procedure. The corresponding change in the calculated coefficient of friction was 0.33 ± 0.04 (range 0.28 to 0.43) to 0.44 ± 0.07 (range 0.32 to 0.56). For the thread-friction no corresponding trend for consecutive tightening repetitions could be noticed. CONCLUSIONS In the investigated implant-abutment units, repeated use of a coated abutment screw appears to increase the friction of the screw head and thereby decrease the preload. These results indicate that a pre-used coated implant-abutment-screw will fail reaching optimal screw preload.
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Affiliation(s)
- K. Sagheb
- Department of Prosthodontics and Materials Science, University Medical Center of the University of Mainz, Augustusplatz 2, 55131 Mainz, Germany
| | - C.-I. Görgen
- Department of Prosthodontics and Materials Science, University Medical Center of the University of Mainz, Augustusplatz 2, 55131 Mainz, Germany
| | - S. Döll
- Department of Prosthodontics and Materials Science, University Medical Center of the University of Mainz, Augustusplatz 2, 55131 Mainz, Germany
| | - I. Schmidtmann
- Institute for Medical Biostatistics, Epidemiology and Informatics, University Medical Center of the University of Mainz, Obere Zahlbacher Straße 69, 55131 Mainz, Germany
| | - S. Wentaschek
- Department of Prosthodontics and Materials Science, University Medical Center of the University of Mainz, Augustusplatz 2, 55131 Mainz, Germany
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Singh M, Bhargava A, Nagpal A, Chaudhary A. Evaluation of physical changes due to simulated loading on prosthetic screw supporting 4- and 6-unit implant prosthesis: An in vitro study. J Indian Prosthodont Soc 2022; 22:389-397. [PMID: 36511074 PMCID: PMC9709871 DOI: 10.4103/jips.jips_48_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 07/15/2022] [Accepted: 08/03/2022] [Indexed: 11/07/2022] Open
Abstract
Aim Screw loosening is a very common cause of failures in implant prosthodontics. In order to avoid screw fracture, it is imperative to understand the mechanical behavior of the screw and the dynamics it is subjected to intraorally. The present study was conducted to qualitatively evaluate and compare the morphological changes, surface defects, and cracks observed under a scanning electron microscope (SEM) in the prosthetic screw. Settings and Design Two Stainless steel edentulous mandible models were fabricated on the basis of all on four and all on six concepts by using CAD design. Screw retained prosthesis were fabricated for both the models and total number of 80 prosthetic screws were made up of Ti6Al4V. Materials and Methods Eighty prosthetic screws (N = 80) used in four- and six-unit implant-retained cast hybrid denture were subjected to cyclic loading of 1.5 million cycles and 3 million cycles, simulating a 5 and 10 years of usage, respectively. Once the simulated cycles had been completed in all subgroups, each prosthetic screw was inspected under SEM (×150-×1000) for any changes. Statistical Analysis The data thus obtained were statistically analyzed using SPSS 12.0 software and P < 0.005 was considered statistically significant. Results The study revealed statistically significant (P < 0.005) changes (like morphological changes, surface defects, crack initiation, and propagation) in the prosthetic screws after exposing them to predefined test conditions (P < 0.001). Conclusion It can be concluded that the prosthetic screws need to be changed after a period of clinical use of 5 years irrespective of the number of implants used for rehabilitation. Further, the tilt of the abutment and numbers of implants also contribute to the stresses on the implant-supported prostheses.
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Affiliation(s)
- Mansi Singh
- Department of Prosthodontics and Crown and Bridge, Santosh Deemed to be University, Ghaziabad, Uttar Pradesh, India
| | - Akshay Bhargava
- Department of Prosthodontics and Crown and Bridge, Santosh Deemed to be University, Ghaziabad, Uttar Pradesh, India
| | - Abhishek Nagpal
- Department of Prosthodontics and Crown and Bridge, Santosh Deemed to be University, Ghaziabad, Uttar Pradesh, India
| | - Aditya Chaudhary
- Department of Prosthodontics and Crown and Bridge, ITS Dental College and Hospital, Greater Noida, Uttar Pradesh, India
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Saad I, Salem S. Knowledge, awareness, and perception of dental students, interns, and freshly graduated dentists regarding dental implant complications in Saudi Arabia: a web-based anonymous survey. BMC Oral Health 2021; 21:161. [PMID: 33766004 PMCID: PMC7995726 DOI: 10.1186/s12903-021-01506-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Accepted: 03/09/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND It is necessary for dental students and freshly graduated dentists to apply their education and practice to different clinical and preclinical procedures. The implant success rate and durability are high. Therefore, this study was designed to assess the level of knowledge, awareness and perception of dental students, interns and freshly graduated students regarding dental implant complications in Saudi Arabia. METHODS A cross-sectional study design using a web-based method was conducted at different dental institutions in Saudi Arabia from December 2019 to March 2020. Data were collected from all (n = 288) undergraduate students, interns and freshly graduated dentists using a pretested standardized self-administered web-based questionnaire that was prepared and circulated using a template provided by Google Forms (Google, Inc., USA). Descriptive statistics and chi-square tests were performed to analyse the data using SPSS (version 20). RESULTS A total of 288 participants completed the questionnaire, with a response rate of 83.4%. Of the total participants, 37.5% showed a good level of knowledge regarding dental implant procedures, and 38.9% showed the same level of knowledge regarding implant complications. The most important cause of complications associated with dental implants was case selection, which accounted for 54.17%. Most participants (58.33%) chose massive bone loss related to implant failure as the most common late dental complication, while 26.39% chose postoperative infection as the most common early dental complication. In addition, 30.56% of the participants selected screw loosening as the most frequent mechanical complication. However, lack of implant primary stability was the most common hard-tissue implant complication. Based on aesthetic and reversible complications, restorations that were too buccal or too palatal and prosthetic-related, respectively, were the least common dental implant complications. CONCLUSIONS The level of knowledge among participants regarding dental implant complications differed among the institutions participating in this study. This difference reflects a significant variation that necessitates reviewing and standardizing dental implant curricula among these institutions.
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Affiliation(s)
- Islam Saad
- Department of Periodontology and Oral Medicine, College of Dentistry, Qassim University, King Abdulaziz Road, Mulaidah, Buraidah, Qassim, 51452, Kingdom of Saudi Arabia.
| | - Suzan Salem
- Department of Maxillofacial Surgery and Diagnostic Science, College of Dentistry, Qassim University, King Abdulaziz Road, Mulaidah, Buraidah, Qassim, 51452, Kingdom of Saudi Arabia
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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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