RESUMO
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.
Assuntos
Coroas , Dente Suporte , Projeto do Implante Dentário-Pivô , Falha de Restauração Dentária , Torque , Humanos , Projeto do Implante Dentário-Pivô/efeitos adversos , Dente Suporte/efeitos adversos , Coroas/efeitos adversos , Parafusos Ósseos/efeitos adversos , Prótese Dentária Fixada por Implante/efeitos adversos , Análise do Estresse Dentário , Técnicas In VitroRESUMO
OBJECTIVE: To analyze the influence of 3-mm high abutments with different shapes (cylindrical abutment vs. wide abutment) on marginal bone-level changes (bone loss and bone remodeling). The influence of abutment shape on implant success, probing pocket depth (PPD), and bleeding on probing (BoP) was studied as secondary objectives. MATERIALS AND METHODS: Patients with a partially edentulous area requiring fixed dental prostheses by two implants in the posterior mandible or maxilla were included. The implants were 1 mm subcrestally placed, and osseointegration healing was submerged. Three-mm high abutments with two different shapes were randomly placed in second-stage surgery: cylindrical abutments (cylindrical group) and wide abutments (wide group). Marginal bone-level changes were measured using parallelized periapical radiographs at abutment placement, at definitive prosthesis placement, and at 1, 3, 6, and 12 months after loading. PPD and BoP were likewise measured at the control visits. RESULTS: Sixty-four dental implants in 25 patients were included. Statistically significant differences were found in bone-level changes. The cylindrical group exhibited less mean marginal bone remodeling (MBR) and marginal bone loss (MBL) than the wide group (p < .05). Moreover, the cylindrical group showed significantly less BoP (p < .05). CONCLUSION: Abutment shape had a significant influence upon marginal bone-level changes during the first 12 months. Cylindrical abutments caused less MBR and MBL than wide abutments. More clinical studies involving longer follow-ups and analyzing other abutment modifications are needed to improve our understanding of how abutments can affect peri-implant tissue stability.
Assuntos
Perda do Osso Alveolar , Dente Suporte , Implantes Dentários , Carga Imediata em Implante Dentário , Humanos , Perda do Osso Alveolar/diagnóstico por imagem , Perda do Osso Alveolar/etiologia , Projeto do Implante Dentário-Pivô/efeitos adversos , Implantação Dentária Endóssea/efeitos adversos , Maxila/cirurgia , OsseointegraçãoRESUMO
Peri-implant mucosal integration is becoming a critical aspect for long term implant health and can be triggered the selection of implant components. The aim of this review is therefore to investigate the evidence concerning implant connection and abutment characteristics (abutment materials, design, handling) as predisposing or precipitating factor for peri-implant mucositis and peri-implantitis. Although the evidence that these features can directly predispose/precipitate peri-implant diseases is limited, there are -few- studies showing a potential role of the implant connection, trans-mucosal configuration, and handling in the development of early bone loss and/or peri-implantitis. With bone level implants, conical internal connections (with inherent platform switching) might be preferred over internal flat-flat and external connections to decrease the risk of early bone loss and potentially the risk of peri-implant disease. Moreover, there is a trend suggesting moving the prosthetic interface coronally (to the juxta-mucosal level) as soon as possible to reduce the number of disconnections and to limit the risk of cements remnants. This can be achieved by choosing a tissue-level implant or to place a trans-mucosal abutment (one abutment-one time approach) to optimize the peri-implant soft tissue seal. In absence of evidence for the biocompatibility regarding several restorative materials, biocompatible materials such as titanium or zirconia should be preferred in the trans-mucosal portion. Finally, higher implants (≥2mm) with an emergence angle below 30° seem more favourable. It should however be noted that some of this information is solely based on indirect information (such as early bone loss) and more research is needed before making firm recommendations about abutment choice. [Correction added on 13 March 2023, after first online publication: 'longer implants (≥2mm)' was changed to 'higher implants (≥2mm)' in this version.].
Assuntos
Implantes Dentários , Peri-Implantite , Humanos , Peri-Implantite/etiologia , Implantes Dentários/efeitos adversos , Projeto do Implante Dentário-Pivô/efeitos adversos , Fatores Desencadeantes , Dente SuporteRESUMO
STATEMENT OF PROBLEM: Internal conical connections have become the primary choice for implant-supported restorations. However, studies that identified the risk indicators for mechanical complications and diagnosed the prognosis of the implant-supported restorations are lacking. PURPOSE: The purpose of this retrospective clinical study was to evaluate the incidence and consequences of mechanical complications in components of internal conical connection implants and to analyze the risk indicators. MATERIAL AND METHODS: A total of 428 patients with 898 internal conical connection implants were included in the study, and mechanical complications over the 14-year observation period were evaluated. The Cox proportional hazard regression model was used to analyze significant effects on mechanical complications, which were presented as hazard ratio and 95% confidence interval. RESULTS: Mechanical complications occurred in 430 (47.9%) implants and 248 (57.9%) patients: screw loosening (46.4% of implants, 56.8% of patients); screw fracture (2.6% of implants, 4.4% of patients); abutment fracture (11.4% of implants, 21.3% of patients); and implant fracture (3.5% of implants, 5.4% of patients). Implant restorations replacing molars showed the highest risk for mechanical complication (hazard ratio 12.82; 95% confidence interval 2.73-60.31) and for fracture of all components. Men had a higher risk of mechanical complication than women (hazard ratio 2.00; 95% confidence interval 1.55-2.59), and the risk of fracture was higher in all components. With increased splinted implants, the risk of mechanical complication (hazard ratio 0.67; 95% confidence interval 0.49-0.93) and component fracture (hazard ratio 0.73; 95% confidence interval 0.29-0.89) decreased. Gold screws had a lower risk of screw loosening (hazard ratio 0.74; 95% confidence interval 0.58-0.94) than titanium screws, but a higher risk of fracture (hazard ratio 3.45; 95% confidence interval 1.42-8.36). The smaller the implant diameter, the higher the risk of implant fracture (hazard ratio 0.01; 95% confidence interval 0.00-0.05). CONCLUSIONS: Abutments were most frequently fractured among the components of internal conical connection type implants. Molar implant-supported restorations and male patients had higher risks of mechanical complications, and as the number of splinted implants in a prosthesis increased, the risk decreased. Gold screws showed less risk of screw loosening and higher risk of fracture than titanium screws. Narrow-diameter implants had a higher risk of fracture.
Assuntos
Implantes Dentários , Humanos , Masculino , Feminino , Implantes Dentários/efeitos adversos , Estudos Retrospectivos , Titânio , Prótese Dentária Fixada por Implante/efeitos adversos , Dente Suporte , Falha de Restauração Dentária , Ouro , Projeto do Implante Dentário-Pivô/efeitos adversosRESUMO
Aim: Abutment screw loosening of implant-supported prosthesis causes a mismatch between the abutment and the implant. This screw loosening is influenced by the implant-abutment connection type, however, with contradictory results reported in different studies. The present study evaluates the stability of abutment-implant connections in three different systems before and after the fatigue test. Settings and Design: Thirty implants (4.3 mm in diameter and 12 mm in length) were divided into three groups of 10: Implantium, Zimmer, and straight internal hexagonal connection (SIC) implants. Materials and Methods: Two torques of 35 Ncm with an interval of 10 min were applied, followed by measuring removal torque value (RTV). The samples were re-torqued and then underwent a simulation of 1-year chewing clinical performance of dental implant under axial force of 400 N, with a frequency of 8 Hz (one million cycles). After fatigue test, the RTV was calculated and recorded. Statistical Analysis: The mean RTVs obtained before and after cyclic load were analyzed by SPSS version 22 software using multivariate analysis. Results: Significant differences in RTV and role of cyclic loading were found between SIC and Implantium groups (P = 0.006 and 0.021, respectively), as well as between Zimmer and SIC groups (P = 0.032 and 0.006, respectively), but not between Zimmer and Implantium groups (P = 0.771 and 0.248, respectively). Conclusion: The type of connection could affect the screw loosening, the preload loss, and the implant component stability. SIC group revealed the highest RTVs before and after cyclic loading.
Assuntos
Dente Suporte , Projeto do Implante Dentário-Pivô , Projeto do Implante Dentário-Pivô/efeitos adversos , Projeto do Implante Dentário-Pivô/métodos , Análise do Estresse Dentário , Torque , Parafusos ÓsseosRESUMO
BACKGROUND: The fracture of a Morse tapered abutment connection in an osseointegrated implant is one of the most serious mechanical complications, and it is extremely hard to deal with this complication in clinical practice. PURPOSE: The aim of this study was to explore the cumulative mechanical complications focus on abutment of a platform switching Morse taper connection implant system after loading, and to perform a retrospective, approximately 1- to 9-year follow-up study to identify the predisposing factors. MATERIALS AND METHODS: A total of 495 patients with 945 fitted implants were enrolled in this study with a follow-up from January 2012 to January 2020. The data of mechanical complications of the abutment, including abutment fracture (AF) and abutment screw loosening (ASL), and possible causative factors were extracted and evaluated statistically. RESULTS: A total of 25 out of 945 (2.65%) cumulative abutment mechanical complications occurred. AF was the most common complication (n = 13, 1.38%), followed by ASL (n = 12, 1.27%). For AF, gender, type of prosthesis, abutment design, and implant diameter were identified as the causative factors. AF was mostly observed in the single crown of males in molar areas, while ASL was more likely to occur on an angled abutment than on a non-angled abutment. Moreover, the abutment with the positioning index (/X) had a higher incidence of fracture than the abutment without the positioning index (C/). CONCLUSIONS: This study shows that the Morse taper connection is a safe abutment connection. AF occurs more frequently within single crowns in molar area of males, especially with the positioning index (/X), while ASL is more likely to occur in an angled abutment.
Assuntos
Implantes Dentários , Coroas , Dente Suporte , Projeto do Implante Dentário-Pivô/efeitos adversos , Seguimentos , Humanos , Masculino , Estudos RetrospectivosRESUMO
OBJECTIVE: To evaluate the long-term integrity of implant-abutment complexes in implant systems with two internal conical angles. MATERIAL AND METHODS: 12,538 bone-level implants of two systems placed between January 2012 and December 2018 were retrospectively analyzed. Cumulative abutment/implant fracture rates in systems with larger (LA, 7.5°) and smaller (SA, 5.7°) internal conical angles were estimated using the Kaplan-Meier analysis and compared between groups. The association between implant systems and jammed abutment retrievability was evaluated by multivariable generalized estimating equation logistic regression modeling. RESULTS: For LA, the 8-year cumulative incident rate was 0.10% (95% confidence interval (CI): 0-0.24%) for implant fracture and 0.26% (95% CI: 0.11%-0.41%) for abutment fracture, demonstrating a significant difference in gender (p = .03), implant diameter (p = .01), jaw (p = .006), and antagonist tooth (p < .001). For SA, the 8-year cumulative incident rate was 0.38% (95% CI: 0-0.79%) for implant fracture and 2.62% (95% CI: 0.05%-5.13%) for abutment fracture, which was influenced by implant diameter (p < .001) and site (p = .03). The cumulative implant/abutment fracture rate was lower for LA implants, particularly for LA implant-supported single crowns (SCs) (p < .05). The abutment-retrieval success rate was 92.9% for LA and 57.1% for SA (p = .055). CONCLUSION: LA implants exhibited a lower incidence of fracture in abutment-implant complexes and a relatively higher retrievability success rate for jammed abutments.
Assuntos
Dente Suporte , Implantes Dentários , Coroas , Projeto do Implante Dentário-Pivô/efeitos adversos , Implantes Dentários/efeitos adversos , Análise do Estresse Dentário , Estudos RetrospectivosRESUMO
PURPOSE: The aim of this in vitro study was to evaluate the mechanical behavior regarding dynamic fatigue of different implant-abutment connections and the unitary indication of abutments for all regions of the mouth. MATERIALS AND METHODS: This experimental study developed according to international standards (ISO 14801:2007) was performed using five types of implants and abutments: G1-external hex smart implant and 17-degree universal abutment (EHS); G2-cortical external hex implant and 17-degree universal abutment (EHTi); G3-internal hex implant and 30-degree universal abutment (IH); G4-Morse taper implant (11.5 degrees) and 17-degree universal abutment (MT11.5); and G5- Morse taper implant (16 degrees) and 30-degree universal abutment (MT16). A 15-Hz cyclic loading was applied to the specimens with the maximum number of cycles set at 5 × 106. Success was defined when three samples supported 5 million cycles without failure. The maximum load supported from each group after dynamic loading was recorded. The Spearman correlation and the Lowess method were used to analyze the correlation between the number of cycles and the applied load, and the Kruskal-Wallis and Nemenyi tests were used for comparison between the abutments when reaching 5 million cycles. RESULTS: There was a negative correlation (r < 0.00) and significant difference (P < .05) between the number of cycles and the load for each type of implant and abutment. The load values supported by each group after cyclic loading to achieve 5 million cycles were as follows: EHS, 225 N; EHTi, 215 N; IH, 220 N; MT11.5, 210 N; and MT16, 240 N. The MT16 implant-abutment assembly presented a significantly higher load (P = .024) than the MT11.5 implant-abutment assembly. CONCLUSION: All implant-abutment connections investigated in this study resisted average occlusal force values reported as acceptable in the literature and may be indicated for any region of the mouth.
Assuntos
Coroas , Projeto do Implante Dentário-Pivô , Dente Suporte , Projeto do Implante Dentário-Pivô/efeitos adversos , Análise do Estresse Dentário , Fadiga , Humanos , Teste de Materiais , Reprodutibilidade dos TestesRESUMO
PURPOSE: The aim of this study was to test in vitro the bacterial microleakage at the Morse taper implant-abutment connection with switched platform subjected to functional load and thermocycling. MATERIALS AND METHODS: A total of 48 Morse taper implant-abutment connections with switched platforms (12 implants per group) were used. The abutments were attached to implants and presented in four groups: group 1, control; group 2, subjected to thermocycling; group 3, subjected to cyclic compressive loading; and group 4, subjected to thermocycling and cyclic compressive loading. All groups were then inoculated in Eppendorf tubes including three types of bacterial suspensions: Enterococcus faecalis, Staphylococcus aureus, and Pseudomonas aeruginosa for 7 and 14 days to detect possibility of bacterial infiltration from outside to the internal chamber of the implant. RESULTS: Implants not exposed to cyclic loading and thermocycling (group 1) and those exposed to thermocycling (group 2) exhibited no infiltration of E faecalis, S aureus, and P aeruginosa from outside to the inner chamber of the implant, while infiltration of P aeruginosa was only observed in implants subjected to cyclic loading only (group 3) and those subjected to cyclic loading in conjunction with thermocycling (group 4). CONCLUSION: Microbial leakage at the implant-abutment connection is influenced by the applied load alone and in combination with thermocycling; however, E faecalis and S aureus did not leak at the implant-abutment connection even under these circumstances. Only P aeruginosa infiltrated inside the implant-abutment connection, which might be caused by its swarming motility.
Assuntos
Implantes Dentários , Infiltração Dentária , Dente Suporte , Projeto do Implante Dentário-Pivô/efeitos adversos , Implantes Dentários/efeitos adversos , Infiltração Dentária/etiologia , Enterococcus faecalis , Humanos , Teste de MateriaisRESUMO
This retrospective clinical study was conducted to evaluate the clinical usefulness of a freely removable microlocking implant prosthesis (MLP) that was developed to overcome the problems with conventional implant prostheses. A total of 54 patients (male: 31, female: 23) and 100 implant prostheses were included. Patients were divided into three groups such as 6-12 months, 12-18 months, and 18-24 months according to the used period after implant prosthesis delivery, and the patients in each group were recalled for examinations of survival rate, marginal bone resorption, peri-implant soft tissue indices, and complications. The prosthetic complications were analysed by combining the recorded chart data during the periodic checks including the last call for this study. During a 2-year observation period, all the implants showed a 100% survival rate without clinical mobility and functional problems. There was no significant difference in marginal bone resorption, plaque index, and bleeding index over the observation period after implant prosthesis delivery. Probing depth of the 18-24 months group (1.5 ± 0.19 mm) was significantly lower than that of the 6-12 months group (p < 0.05). The main complication was abutment loosening (4%), followed by implant prosthesis fracture (2%) and food impaction (2%) which were recorded. Within the limits of the present study, the implant prostheses with MLP are considered to be an applicable and predictable treatment method.
Assuntos
Prótese Dentária Fixada por Implante , Reabsorção Óssea , Projeto do Implante Dentário-Pivô/efeitos adversos , Implantes Dentários , Placa Dentária/etiologia , Retenção em Prótese Dentária , Prótese Dentária Fixada por Implante/efeitos adversos , Desenho de Equipamento , Feminino , Hemorragia Gengival/etiologia , Humanos , Masculino , Estudos Retrospectivos , Fatores de TempoRESUMO
The objective of this systematic review was to compare the conical internal connection (IC) with the external hexagonal connection (EH) on the occurrence of marginal bone loss (ΔMBL). Different databases were used to carry out the selection of the elected studies. The studies were judged according to the risk of bias as "high", "low" and "unclear" risk. For the meta-analysis we included only studies that could extract the data of ΔMBL, survival rate (SR) and probing depth (PD). No statistically significant differences were found for ΔMBL data at one, three- and five-year survival rates between implant connections (p <0.05), however statistically significant differences were found for PD between EH and IC implants (1-year follow-up) -0.53 [95%CI -0.82 to -0.24, p = 0.0004]. This present systematic review demonstrated that there are no significant differences between IC and EH implants for both ΔMBL and SR at 1, 3 e 5 years after functional loading, although better PD values were observed for implants pertaining to the IC connections. Considering the high heterogeneity, more well-delineated, randomized clinical trials should be conducted.
Assuntos
Perda do Osso Alveolar/etiologia , Dente Suporte/efeitos adversos , Projeto do Implante Dentário-Pivô/efeitos adversos , Implantes Dentários/efeitos adversos , Humanos , Valores de Referência , Medição de Risco , Fatores de Risco , Fatores de TempoRESUMO
Because the main complication of implant-supported prostheses is torque loosening and/or fixation screw fracture, the goal of this study was to evaluate the torque before and after fatigue (screw placement and removal, respectively), single load-to-failure (compression test), and stress concentration of straight and angled abutments. Eighty implants were included in polyurethane cylinders. Half of the implants received straight abutments (group S, n = 40) and the other half received angled abutments (group A, n = 40). The abutments for cemented prostheses were installed with a torque of 20 Ncm. Eighty titanium structures were machined and cemented on the abutments with zinc-phosphate cement. After storage for 24 hours, half of the specimens had their torque loosening evaluated and were then immediately submitted to a compressive test in a universal testing machine (1 mm/minute, 1,000 kgf), while the other half were subjected to cyclic fatigue (200 N at 2 Hz for 2 × 106 cycles at 37°C) as an aging protocol (n = 20 from each group). The aged samples then had their torque loosening measured and were also submitted to the compression test. Representative samples were evaluated by scanning electron microscopy. Two bidimensional models similar to the in vitro specimens were created and analyzed using the finite element method to evaluate the stress concentration. Data from the in vitro tests were submitted to two-way analysis of variance and Tukey test, both with significance at P = .5. The results show that angled abutments are less capable of maintaining the installation torque and are less resistant during the single load-to-failure test. The von Mises stress concentration was higher for group A in the cervical region. The straight abutments have better prognosis than angled abutments and less susceptibility to mechanical failures.
Assuntos
Dente Suporte , Dente Suporte/efeitos adversos , Projeto do Implante Dentário-Pivô/efeitos adversos , Projeto do Implante Dentário-Pivô/métodos , Falha de Restauração Dentária , Análise do Estresse Dentário , Humanos , TorqueRESUMO
PURPOSE: To identify associations between early implant failure and prosthodontic characteristics that could be used to guide subsequent continuous quality improvement efforts of patient care. MATERIALS AND METHODS: An implant-level analysis was performed in which data were abstracted from a prospective clinical database of all adult patients treated with implants and followed up from January 2000 through December 2014 at the Department of Dental Specialties at Mayo Clinic in Rochester, Minnesota. These data were used to determine time to implant failure. Associations between prosthodontic characteristics and early implant failure were evaluated with Cox proportional hazards regression models and summarized with hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: Among 8762 implants in 2787 patients, 395 (4.5%) failed within the first year of placement at a mean (SD) of 127 (97) days (range, 2-364 days). Univariable analysis showed no associations between early implant failure and use of a cover screw, prosthesis, or definitive or provisional prosthesis at implant placement. Three of 25 single crowns failed, and use of a single crown was significantly associated with early implant failure (HR, 3.94; 95% CI, 1.08-14.35; P = 0.04). This study identified no significant associations between prosthodontic characteristics identified after implant placement and early implant failure. CONCLUSIONS: Use of a prosthesis at implant placement, use of a definitive or provisional prosthesis, and early mechanical complications were not associated with increased risk of early implant failure. Quality improvement efforts should focus on aspects of decision making that aim to decrease surgical complications.
Assuntos
Implantes Dentários/efeitos adversos , Falha de Restauração Dentária/estatística & dados numéricos , Adulto , Idoso , Coroas/efeitos adversos , Projeto do Implante Dentário-Pivô/efeitos adversos , Implantes Dentários para Um Único Dente/efeitos adversos , Prótese Dentária Fixada por Implante/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Fatores de Risco , Fatores de TempoRESUMO
Abstract The objective of this systematic review was to compare the conical internal connection (IC) with the external hexagonal connection (EH) on the occurrence of marginal bone loss (ΔMBL). Different databases were used to carry out the selection of the elected studies. The studies were judged according to the risk of bias as "high", "low" and "unclear" risk. For the meta-analysis we included only studies that could extract the data of ΔMBL, survival rate (SR) and probing depth (PD). No statistically significant differences were found for ΔMBL data at one, three- and five-year survival rates between implant connections (p <0.05), however statistically significant differences were found for PD between EH and IC implants (1-year follow-up) -0.53 [95%CI -0.82 to -0.24, p = 0.0004]. This present systematic review demonstrated that there are no significant differences between IC and EH implants for both ΔMBL and SR at 1, 3 e 5 years after functional loading, although better PD values were observed for implants pertaining to the IC connections. Considering the high heterogeneity, more well-delineated, randomized clinical trials should be conducted.
Assuntos
Humanos , Implantes Dentários/efeitos adversos , Perda do Osso Alveolar/etiologia , Dente Suporte/efeitos adversos , Projeto do Implante Dentário-Pivô/efeitos adversos , Valores de Referência , Fatores de Tempo , Fatores de Risco , Medição de RiscoRESUMO
OBJECTIVES: The objective of this systematic review was to assess the influence of implant-abutment connection and abutment material on the outcome of implant-supported single crowns (SCs) and fixed dental prostheses (FDPs). METHODS: An electronic Medline search complemented by manual searching was conducted to identify randomized controlled clinical trials, prospective and retrospective studies with a mean follow-up time of at least 3 years. Patients had to have been examined clinically at the follow-up visit. Failure and complication rates were analyzed using robust Poisson regression, and comparisons were made with multivariable Poisson regression models. RESULTS: The search provided 1511 titles and 177 abstracts. Full-text analysis was performed for 147 articles resulting in 60 studies meeting the inclusion criteria. Meta-analysis of these studies indicated an estimated 5-year survival rate of 97.6% for SCs and 97.0% for FDPs supported by implants with internal implant-abutment connection and 95.7% for SCs and 95.8% for FDPs supported by implants with external connection. The 5-year abutment failure rate ranged from 0.7% to 2.8% for different connections with no differences between the types of connections. The total number of complications was similar between the two connections, yet, at external connections, abutment or occlusal screw loosening was more predominant. Ceramic abutments, both internally and externally connected, demonstrated a significantly higher incidence of abutment fractures compared with metal abutments. CONCLUSION: For implant-supported SCs, both metal and ceramic abutments with internal and external connections exhibited high survival rates. Moreover, implant-supported FDPs with metal abutments with internal and external connections for also showed high survival rates.
Assuntos
Dente Suporte , Projeto do Implante Dentário-Pivô , Implantação Dentária Endóssea , Prótese Dentária Fixada por Implante , Cerâmica/efeitos adversos , Cerâmica/uso terapêutico , Coroas/efeitos adversos , Dente Suporte/efeitos adversos , Projeto do Implante Dentário-Pivô/efeitos adversos , Implantação Dentária Endóssea/efeitos adversos , Implantação Dentária Endóssea/métodos , Prótese Dentária Fixada por Implante/efeitos adversos , Falha de Restauração Dentária , Humanos , Metais/efeitos adversos , Metais/uso terapêuticoRESUMO
OBJECTIVES: To investigate the impact of progressive bone loss in an experimental peri-implantitis model in the dog upon the implant stability quotient (ISQ) measured in the course of induced and spontaneous conditions of disease, and to evaluate the association between the clinical parameters and ISQ. MATERIALS AND METHODS: Seventy-two implants were placed in 12 Beagle dogs. Of these, 36 implants in six dogs were assessed during ligature-induced peri-implantitis (three timepoints) and at one timepoint following a period of spontaneous progression. The ISQ was recorded using resonance frequency analysis (RFA). Furthermore, the clinical peri-implant parameters were registered at four sites per implant at each timepoint. Marginal bone loss (MBL) was determined using computed tomography at four sites per implant and bone-to-implant contact (BIC) was assessed from histological samples. A linear regression model was estimated by generalized estimation equations (GEEs) in order to study the MBL-ISQ values at each measurement timepoint. Pearson's correlation test was applied. RESULTS: None of the implants failed during the study period. At implant level, a strong negative correlation was found for all timepoints between ISQ and MBL (r = -0.58; p < 0.001). Accordingly, as follow-up progressed, lower ISQ and higher MBL values were observed. A prediction of MBL depending on the ISQ values and timepoints showed a decrease in one ISQ unit to be related to ~1 mm of MBL. Likewise, a statistically significant correlation was found between BIC and ISQ evaluated after spontaneous chronification of peri-implantitis (r = 0.34; p = 0.04). Nevertheless, the ISQ values failed to correlate to any of the clinical parameters recorded. CONCLUSION: Resonance frequency analysis seems accurate in diagnosing progressive bone loss, as a statistically significant decrease in ISQ was recorded in the course of peri-implant disease. Nevertheless, the clinical relevance of this observation as a diagnostic tool is debatable, since implant stability remains high.
Assuntos
Perda do Osso Alveolar/diagnóstico , Implantação Dentária Endóssea/efeitos adversos , Perda do Osso Alveolar/diagnóstico por imagem , Perda do Osso Alveolar/patologia , Animais , Dente Suporte/efeitos adversos , Projeto do Implante Dentário-Pivô/efeitos adversos , Implantes Dentários/efeitos adversos , Cães , Peri-Implantite/diagnóstico , Peri-Implantite/etiologia , Peri-Implantite/patologia , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios XRESUMO
OBJECTIVE: The aim of this study was to assess the effect of different abutment configurations on peri-implant soft and hard tissue healing. MATERIALS AND METHODS: Two-piece dental implants, 3.5 mm in diameter and 8 mm in length, were placed in four beagle dogs. Two different transmucosal healing abutment configurations were randomly selected: one with a wide emergence profile (WE) (45° angulation with implant long axis) and the other with a narrow emergence profile (NE) (15° angulation with implant long axis). After four months of healing, the animals were sacrificed. Micro-CT scans were taken for mesio-distal analysis; subsequently, the biopsies were prepared for bucco-lingual histometric analyses. Several measurements were taken using the following reference points: marginal mucosal level (MML), apical barrier epithelium (aBE), implant shoulder (IS), marginal bone crest (BC), and first bone-to-implant contact (fBIC). RESULTS: In the micro-CT analysis, the distance from IS-fBIC was 1.11 ± 0.66 mm for WE and 0.12 ± 0.21 mm for NE (p = 0.004). The IS-BC of WE was -0.54 ± 0.80 mm, whereas NE presented 0.76 ± 0.48 mm (p = 0.002). The histometric analysis showed that both groups presented comparable dimensions of peri-implant biologic width (p > 0.05). However, in the distance from IS to BC, the WE showed a mean distance of -0.66 ± 0.78 mm while NE was 0.06 ± 0.42 mm (p = 0.039); the IS to fBIC was 0.89 ± 0.68 mm for WE while NE was 0.30 ± 0.30 mm (p = 0.041). CONCLUSION: The design of the transmucosal component can influence the establishment of the peri-implant biologic width. The flat and wide emergence profile induced an apical displacement of the peri-implant biologic width and more bone loss.
Assuntos
Processo Alveolar/patologia , Projeto do Implante Dentário-Pivô , Implantação Dentária Endóssea , Periodonto/patologia , Processo Alveolar/diagnóstico por imagem , Processo Alveolar/cirurgia , Animais , Dente Suporte/efeitos adversos , Projeto do Implante Dentário-Pivô/efeitos adversos , Projeto do Implante Dentário-Pivô/métodos , Implantação Dentária Endóssea/efeitos adversos , Cães , Periodonto/diagnóstico por imagem , Periodonto/cirurgia , Cicatrização , Microtomografia por Raio-XRESUMO
BACKGROUND: The effect of different maintenance time of torque application and screw loosening in full-arch implant-supported prosthesis remains uninvestigated. PURPOSE: To examine the effect of different maintenance time of torque application on detorque values of implant abutment screw in full-arch implant-supported fixed complete denture. MATERIALS AND METHODS: Passively fitting framework supported by four implants stabilized on resin model torqued to 35 N-cm and maintained for different times; instant torque application (protocol A), 10 seconds (protocol B), and 30 seconds (protocol C) were used. Detorque values were recorded during removal of the screws. Comparison between mean torque and detorque values were made using paired sample t-test. The mean removal torque values of each protocol were compared using three-way analysis of variance (ANOVA). RESULTS: The mean removal torque values were lower than the applied torque for all the protocols. The highest mean removal torque value was found in the immediate protocol (A) (24.44 ± 1.7), followed by the 30 seconds protocol (C) (23.37 ± 1.75), and then by the 10 seconds protocol (B) (23.35 ± 1.6). All these differences were found to be statistically significant between torque and detorque values (P = .001). However, the differences among detorque values were not statistically significant (P > .05). CONCLUSION: The application of 35 N-cm for different maintenance time of torque application on implant abutment screw did not appear to affect the detorque value in a multiple implant-supported fixed prosthesis. Maintaining the torque for prolonged time (10 seconds or 30 seconds) was not significantly associated with higher preload than instant torque application in full-arch implant-supported prosthesis.
Assuntos
Dente Suporte , Prótese Dentária Fixada por Implante/métodos , Prótese Total , Dente Suporte/efeitos adversos , Projeto do Implante Dentário-Pivô/efeitos adversos , Projeto do Implante Dentário-Pivô/métodos , Implantação Dentária Endóssea/efeitos adversos , Implantação Dentária Endóssea/instrumentação , Implantação Dentária Endóssea/métodos , Prótese Dentária Fixada por Implante/efeitos adversos , Falha de Restauração Dentária , Análise do Estresse Dentário , Prótese Total/efeitos adversos , Humanos , Técnicas In Vitro , TorqueRESUMO
AIM: The aim of the present study was to investigate fracture resistance of implant-supported zirconia-based crowns (monolayer vs bilayer) cemented to hybrid abutments. METHODS: Monolayer and bilayer zirconia crowns were constructed and cemented to zirconia hybrid abutments. Crowns were divided into two subgroups: (a) untreated control group; and (b) experimental group, which underwent thermal-cycling mechanical loading in a chewing simulator. Up to 1.2 million stress cycles with simultaneous thermocycling (5 and 55°C) were applied. Samples were finally subjected to static load to fracture. Data were analyzed using one-way analysis of variance and t test. Fractured surfaces were observed using scanning electron microscopy. RESULTS: Monolayer zirconia crowns had a 100% survival rate upon completion of the thermal mechanical loading, whereas bilayer zirconia crowns had a 50% survival rate. The fracture load of monolayer zirconia crowns was significantly higher than that of bilayer crowns. Moreover, the fracture load was significantly reduced in monolayer zirconia crowns after aging. Monolayer zirconia crowns showed bulk fracture within the monolayer, while bilayer crowns exhibited cohesive fracture within the veneering porcelain only. CONCLUSIONS: Monolayer implant-supported hybrid-abutment crowns exhibit significantly higher fracture resistance compared to bilayer crowns, making them better suited to handle higher masticatory loads encountered in the posterior region of the mouth.
Assuntos
Coroas , Projeto do Implante Dentário-Pivô , Prótese Dentária Fixada por Implante , Falha de Restauração Dentária , Coroas/efeitos adversos , Dente Suporte/efeitos adversos , Projeto do Implante Dentário-Pivô/efeitos adversos , Prótese Dentária Fixada por Implante/efeitos adversos , Prótese Dentária Fixada por Implante/métodos , Análise do Estresse Dentário , Humanos , Técnicas In Vitro , Suporte de Carga , ZircônioRESUMO
BACKGROUND: There is a lack of studies evaluating the wear of the male components of the ball attachment systems of implant-retained overdentures. PURPOSE: The purpose of this study was to compare the volumetric wear patterns four commercially used ball abutments. MATERIALS AND METHODS: Forty-eight identical polyethylene and acrylic blocks were fabricated and four groups consisting of 12 polyethylene blocks with two implants and 12 acrylic blocks, which were used as overdentures, were generated (two groups with plastic females, one group with gold and one group with titanium females). Every specimen underwent 5000 insertion and removal cycles (~4.5 years) and retention forces were measured. For the evaluation of volumetric wear, all the ball abutments were scanned before and after the 5000 cycles using a three-dimensional scanner and the data were analyzed using the software supplied by the manufacturer. RESULTS: Statistically significant retention force differences were observed between the groups at each cycle (P < .05). Among the four groups, retention force was lowest in the group with titanium females (5.59 ± 2.27) and highest in the group with gold females (43.0 ± 6.3) at the end of 5000 cycles. Statistically significant dimensional changes in the male components were observed between the groups (P < .05). Volumetric losses were 11%-13% in Group I and II, 1% in Group III, and 25% in Group IV. Group III showed significantly lower volumetric wear whereas Group IV showed significantly higher volumetric wear than all the other groups (P < .001). No significance was detected between Group I and II (P > .05). CONCLUSION: Within the limitations, it can be concluded that although clinical studies are needed to ensure the findings of the present study, due to severe retention loss and volumetric abutment wear, ball attachments with titanium female components should be used with caution.