In Vitro Study of Preload Loss in Different Implant Abutment Connection Designs

The stability and integrity of the abutment-implant connection, by means of a screw, is fallible from the moment the prosthetic elements are joined and is dependent on the applied preload, wear of the components and function. One of the main causes of screw loosening is the loss of preload. The loosening of the screw-abutment can cause complications such as screw fracture, marginal gap, peri-implantitis, bacterial microleakage, loosening of the crown and discomfort of the patient. It is also reported that loosening of the screw/abutment may lead to a failure of osseointegration. It is necessary to evaluate and quantify, with in vitro studies, the torque loss before and after loading in the different connections. Aim: evaluate the influence of implant- abutment connection design in torque maintenance after single tightening, multiple tightening and multiple tightening followed by mechanical cycling. Materials and Methods: 180 Klockner implants divided in 4 groups: 15 SK2 external connection, 25 Ncm tightening torque; 15 KL external connection, 30 Ncm tightening torque; 15 Vega internal connection, 25 Ncm tightening torque; 15 Essential internal connection, 30 Ncm tightening torque. In each group removal torque values (RTV) were evaluated with a digital torque meter, in 3 distinct phases: after one single tightening, 10 multiple tightenings and 10 multiple tightenings and cyclic loading (500 N × 1000 cycles). Results: After one single tightening, and for all connections, RTV were lower than those of insertion, but only for Essential and Vega internal connections this result was statistically significant. After multiple tightening, RTV were significantly lower in all connections. After repeated tightening followed by cyclic loading, mean RTV were significantly lower, when compared to insertion torque. The multiple tightening technique resulted in higher RTV than the single tightening technique, except for Vega implant. The multiple tightening followed by cyclic load, compared to the other phases, was the one that generated the lowest RTV, for all connections. Conclusions: The connection design, in our study, did not seem to influence the maintenance of preload. Loading influenced the loss of preload, in the sense that significantly decreased the removal torque values. The multiple re-tightening technique resulted in higher removal torque values than the single tightening technique. Clinically, our results recommend to retighten retaining screws, a few minutes after insertion

Effect of abutment angulation in the retention and durability of three overdenture attachment systems: An in vitro study

PURPOSE. This in vitro study investigated and compared the durability and retention of three types of attachments. MATERIALS AND METHODS. Three commercially available attachments were investigated: Clix (R), Dalbo-Plus (R) and Locator (R). In total, 72 samples of these attachments were placed in the acrylic resin forms and subjected to mechanical testing (5400 cycles of insertion and removal) over the respective ball or Locator abutments immersed in artificial saliva at pH 7 and 37 degrees C. The abutments were placed at angulations of 0 degrees, 10 degrees and 20 degrees. The retention force was recorded at the beginning and after 540, 1080, 2160, 3240, 4320 and 5400 insertion-removal cycles. RESULTS. The results revealed that there were significant differences in the average values of the insertion/removal force due to angulation (F ((2.48)) = 343619, P<.05) and the type of attachment (F ((7.48)) = 23.220, P<.05). CONCLUSION. Greater angulation of the abutments was found to influence the retention capacity of the attachments, and the fatigue test simulating 5 years of denture insertion and removal did not produce wear in the metal abutments.info:eu-repo/semantics/publishedVersio

In vitro study of preload loss in different implant abutment connection designs

The stability and integrity of the abutment-implant connection, by means of a screw, is fallible from the moment the prosthetic elements are joined and is dependent on the applied preload, wear of the components and function. One of the main causes of screw loosening is the loss of preload. The loosening of the screw-abutment can cause complications such as screw fracture, marginal gap, peri-implantitis, bacterial microleakage, loosening of the crown and discomfort of the patient. It is also reported that loosening of the screw/abutment may lead to a failure of osseointegration. It is necessary to evaluate and quantify, with in vitro studies, the torque loss before and after loading in the different connections. Aim: evaluate the influence of implant- abutment connection design in torque maintenance after single tightening, multiple tightening and multiple tightening followed by mechanical cycling. Materials and Methods: 180 Klockner implants divided in 4 groups: 15 SK2 external connection, 25 Ncm tightening torque; 15 KL external connection, 30 Ncm tightening torque; 15 Vega internal connection, 25 Ncm tightening torque; 15 Essential internal connection, 30 Ncm tightening torque. In each group removal torque values (RTV) were evaluated with a digital torque meter, in 3 distinct phases: after one single tightening, 10 multiple tightenings and 10 multiple tightenings and cyclic loading (500 N × 1000 cycles). Results: After one single tightening, and for all connections, RTV were lower than those of insertion, but only for Essential and Vega internal connections this result was statistically significant. After multiple tightening, RTV were significantly lower in all connections. After repeated tightening followed by cyclic loading, mean RTV were significantly lower, when compared to insertion torque. The multiple tightening technique resulted in higher RTV than the single tightening technique, except for Vega implant. The multiple tightening followed by cyclic load, compared to the other phases, was the one that generated the lowest RTV, for all connections. Conclusions: The connection design, in our study, did not seem to influence the maintenance of preload. Loading influenced the loss of preload, in the sense that significantly decreased the removal torque values. The multiple re-tightening technique resulted in higher removal torque values than the single tightening technique. Clinically, our results recommend to retighten retaining screws, a few minutes after insertion

Rehabilitation of an atrophic jaw with three short implants and a customized milled bar overdenture

Edentulism is frequently observed in older individuals, and edentulous patients with conventional prostheses have reported lack of retention, support, stability, and chewing and phonation failures. Overdentures are a good option for rehabilitation of edentulous patients. Two or more implants supporting a milled bar with attachments may be used for rehabilitation of these patients, since this arrangement allows very limited rotation and vertical movement, thereby increasing patient satisfaction. This report describes a clinical case involving oral rehabilitation of an atrophic jaw with three short implants and a customized milled bar overdenture

Retención y desgaste de tres sistemas de "attachment" para prótesis totales mandibulares sobre implantes - Estudio in Vitro

[eng] Mandibular overdentures retained by two implants are recognised as the first option for treating patients without teeth, as stated by the McGill University (Canada) in its consensus statement in 2002 and the British Society to the prosthodontics study, in your consensus statement of York, published in 2009. Compared to conventional full prosthesis, they provide greater satisfaction for the patient, greater chewing ability and preservation of the residual crest height. Purpose: This in vitro study was investigated and compare the durability and retention capacity of 3 types of attachments. Our working hypothesis states that there is no significant retention loss in different systems "attachments" tested and used in implant supported overdentures over the time and no wear in the metal components that`s requiring replacement during the same period. Materials and Methods: Three commercially available attachments were investigated:(Clix®: Preat Corporation, Santa Ynez, CA, United States; Dalbo-Plus®: Cendres+ Métaux, Biel/Bienne, Switzerland; Locator®: Zest Anchors,Inc ,Escondido, United States), 3 different abutments inclinations (0°, 10° and 20°) . The 72 attachments were placed in acrylic resin form and they were then subjected to mechanical testing (5400 cycles of insertion and removal) over the respective ball or Locator abutments immersed in artificial saliva at pH7 and 37°C, and retention values recorded at eight different times (at the beginning, one month, six months, a year, two years, three years, four years and five years). Results: The results revealed that there were significant differences in the average values of insertion/removal force due to the angulation (F (2, 48) =343619, p<0.05) and the type of attachment (F (7, 48) = 23.220, p < 0.05). An analysis of the results showed that the retention average (insertion and removal) for attachments was always more in inclination of 0° than inclination of 20°. Conclusions: All attachments were tested lose the maximum value of retention force. The abutment inclination influences the intrinsic strength value of each attachment and have effect on its durability over the period of time.[spa] Las sobredentaduras mandibulares retenidas por dos implantes son reconocidas como la primera opción de tratamiento para pacientes edéntulos, tal como recoge la Universidad McGill (Canadá) en su declaración de consenso publicada en 2002 y la sociedad británica para el estudio de la odontología protésica, en su declaración de consenso de York, publicada en 2009. Al compararlas con prótesis completas convencionales, proporcionan una mayor satisfacción del paciente, una mayor capacidad masticatoria y una preservación de altura de la cresta residual. El objetivo de este trabajo es evaluar la durabilidad y capacidad de retención de attachments a largo del tiempo en inclinación de 0°, 10° e 20° y en saliva artificial a 37°C.El diseño experimental tomó en cuenta la existencia de 3 tipos distintos de sistemas de attachments (Clix®: Preat Corporation, Santa Ynez, CA, United States; Dalbo-Plus®: Cendres+ Métaux, Biel/Bienne, Suiza; Locator®: Zest Anchors,Inc ,Escondido, United States), 3 inclinaciones diferentes y uno tipo de saliva artificial ( pH 7). Los 72 attachments fueron testados en una máquina de ensayo de fatiga durante 5400 ciclos (cinco años) y se registraron los valores de retención en ocho momentos diferentes (inicio, un mes, seis meses, un año, dos años, tres años, cuatro años, cinco años).El análisis de los resultados demostró que la media de retención (inserción y desinserción) de los attachments fue siempre mayor en inclinación de 0° do que en inclinación de 20°. Todos los attachments del estudio han perdido valor máximo de retención.La inclinación influye en el valor de la fuerza intrínseca de cada attachment y tiene influencia en su durabilidad a lo largo del tiempo

Oral rehabilitation with an implant-supported mesostructure on a microvascularized mandibular graft

Due to the increased survival of the population, treatment of oral cavity tumour patients is increasingly common. In this context, oral rehabilitation construction methods have been developed to contribute to improving the patient's quality of life. Developments in the areas of oral implantology and rehabilitation, along with microvascularized grafts, have increased the possibility of rehabilitating patients undergoing hemimandibulectomy with more effective and lasting treatment. This article aims to demonstrate an aesthetic and functional oral rehabilitation method, both in terms of the oral cavity and the lower face, in a young patient submitted to a left lateral hemimandibulectomy, using a mesostructure fixed onto implants

Comparison in Four Different Implant Systems of Mechanical Resistance to Maximal Stress in Prosthetic Screws—An In Vitro Study

Micromovements of the implant&ndash;abutment connection influence peri-implant bone preservation. This study evaluates and quantifies the maximal torque after a cycle of implant prosthetic screws tightening using original components. A total of 40 samples were tested: Megagen&reg;&mdash;Daegu, South Korea; Dentium&reg;&mdash;Gangnam-Gu, Seoul, Korea; BIOMET 3i&reg;&mdash;West Palm Beach, FL, USA and BTI&reg;&mdash;&Aacute;lava, Spain. Screws from each manufacturer were subjected to maximal stress force until they fractured. The fracture points were recorded and compared among all samples. To compare the mean values of fracture torques, the reference values associated with each brand and the sample results were used in t-tests. ANOVA (analysis of variance) was used to compare the maximal resistance limit between brands, complemented with Tukey&rsquo;s multiple-comparison test. The maximal considered level of significance was 5%. The average fracture force for the brands was 40.07 Ncm for Megagen&reg;, 53.39 Ncm for Dentium&reg;, 39.74 Ncm for Biomet 3i&reg;, and 68.84 Ncm for BTI&reg;. BTI&reg; screws showed the most resistance to fracture. According to the protocol that was applied, the implant&ndash;abutment connection demonstrated good resistance and a precise fit between these interfaces; therefore, in some cases, the presented values showed a lack of quality control and low fracture resistance

Retention Capacity of Original Denture Adhesives and White Brands for Conventional Complete Dentures: An In Vitro Study

(1) Introduction: Denture adhesives (DAs) promote stability, chewing ability, and quality of life. The objective of this study was to compare the effectiveness of original brand DAs and white brands in their retention of conventional complete dentures. (2) Methods: This study followed the recommendations of the international standard ISO 10873. Three original brands of DA (Corega&reg; Fixa&ccedil;&atilde;o 3D, GlaxoSmithKline&reg;, Stafford Miller Ltd., Dungarvan Co. Waterford, Ireland), KuKident&reg; Pro Procter &amp; Gamble Technical Centres&reg;, Ltd., Whitehal Lane, Germany and Elgydium&reg; Fix, Laborat&oacute;rios URGO&reg; SL, Florida, Spain) were compared to three white brands (Fixa&ccedil;&atilde;o Extra Forte Pingo Doce&reg;, Laborat&oacute;rios Cosmodent&reg;, Cantabria, Spain), Fixador de Pr&oacute;teses (Continente&reg;, Propack&reg;,Gmbh, Ladenburg, Germany) and Creme Fixador de Pr&oacute;teses (Auchan&reg;, Ellipse&reg;, Roubaix, France). Their retention capacities were analyzed using a mechanical test device. (3) Results: The mean retentive ability of original brand adhesives (M = 11.16, SD = 5.27) was significantly higher (t(298) = 11.88; p &lt; 0.001) than that of the white brands (M = 5.92, SD = 1.18). When comparing all brands, statistically significant differences were also observed, F(5.294) = 707.68 (p &lt; 0.001). The generic adhesive results were more homogeneous. The generic brands from Continente&reg; (M = 5.24, SD = 0.94) and Auchan&reg; (M = 5.80, SD = 0.79) were not significantly different, while the Pingo Doce&reg; brand obtained significantly higher mean retention results (M = 6.71, SD = 1.28). (4) Conclusions: The original brands of DA have a significantly higher retentive ability than the white brands. Elygidim&reg; Fix had the worst result of the three original brands, and the product from Pingo Doce&reg; had the best result among the three white brands

Fracture Resistance of CAD/CAM Implant-Supported 3Y-TZP-Zirconia Cantilevers: An In Vitro Study

(1) Introduction: Implant-supported fixed complete dentures are mostly composed of cantilevers. The purpose of this work was to evaluate the fracture resistance of zirconia (Prettau&reg;, second generation, or Ice Zirkon Translucent, first generation) with cantilever lengths of 6 and 10 mm, and zirconia&rsquo;s fracture resistance in relation to an average bite force of 250 N. (2) Materials and methods: Forty structures were created in CAD/CAM and divided into four groups: group A (6 mm cantilever in IZT), group B (10 mm cantilever in IZT), group C (6 mm cantilever in Pz), and group D (10 mm cantilever in pz). The study consisted of a traditional &ldquo;load-to-failure&rdquo; test. (3) Results: A statistically significant result was found for the effect of cantilever length, t(38) = 16.23 (p &lt; 0.001), with this having a large effect size, d = 4.68. The 6 mm cantilever length (M = 442.30, sd = 47.49) was associated with a higher mean force at break than the 10 mm length (M = 215.18, sd = 40.74). No significant effect was found for the type of zirconia: t(38) = 0.31 (p = 0.757), and d = 0.10. (4) Conclusions: All the components with cantilever lengths of 6 mm broke under forces higher than 250 N. Cantilevers larger than 10 mm should be avoided

Comparison of Fracture Strengths of Three Provisional Prosthodontic CAD/CAM Materials: Laboratory Fatigue Tests

Temporary restorations play a fundamental role in oral rehabilitation. They can be used on teeth or implants for a variable period of time during the period prior to rehabilitation with definitive restorations. Temporary or provisional restorations manufactured via CAD/CAM methods are becoming increasingly used in the intermediate phase of the treatment of complex cases. The main objective of this study was to compare the fracture resistance of three materials used in the creation of provisional crowns on implants: polymethyl methacrylate (PMMA), composite resin, and polyether ether ketone (PEEK). Fracture resistance in PMMA (Zirkonzahn Temp Basic® , Gais, South Tyrol, Italy) ranged from 1216.0 N to 1461.2 N, with a mean of 1300.4 N (SD = 97.09). In the composite material (3M Lava Ultimate®, Minnesota, USA), fracture resistance varied between 1343.5 N and 1490.6 N, with a mean of 1425.9 N (SD = 49.03). Lastly, in PEEK (Tecno Med Mineral®, Zirkonzahn®, Gais, South Tyrol, Italy), fracture resistance ranged from 2294.8 N to 2451.7 N, with a mean of 2359.5 (SD = 50.01). The crowns made with the PEEK Tecno Med Mineral® (Zirkonzahn®, Tyrol, Italy) material presented the best fracture resistance, followed by the crowns made with the Lava Ultimate® (3M® ESPE, Minnesota, USA) composite resin material and, finally, those made with the PMMA Temp Basic® (Zirkonzahn®, Tyrol, Italy) material