Clip Attachment Research Articles

Retention Evaluation of Implant-Supported Mandibular Overdenture Using Two Different Attachment Systems: An in Vitro Study

Objective: The purpose of this in vitro study was to evaluate the retentive behavior of implant-supported overdenture using two different attachment systems (locator and milled bar-clip attachment system).
 Methods: Six edentulous mandibular models were fabricated from cold‑cure PMMA; the denture-bearing area of the acrylic resin model was covered by an approximately 1.5 mm thick silicone resilient liner to simulate mucosa. The Study models were divided into three groups: Model A (locator), Model B (milled bar-clip attachment system without extension), and Model C (milled bar-clip attachment system with 1cm extension). However, for each study model, a complete mandibular denture was constructed. Anterior, posterior, and central dislodging forces were measured by digital force gauge at the beginning of the study (Initial retention) and after 540 courses of consecutive pulling and inserting the prosthesis (final retention), which was to simulate six months of overdenture use assuming three daily removals and insertions for oral hygiene practice.
 Results: There were statistically significant differences in retention between the group models, and milled bar-clips attachment systems revealed the highest retentive capacity. However, after six months of simulated use, there was a significant retention loss; retention of Model B recorded the highest percentage loss of 55.1%, while Model A recorded the most minor retention loss of 24%. 
 Conclusions: The bar and clip attachment system offered higher retentive values than the locator attachment system. However, the retention loss was correlated to the particular attachment system, and the bar–clip attachment systems had the highest percent of retention loss. In contrast, the locator attachments were associated with acceptable retention, simplicity, and minimal retention.

Comparison of Attachment Types in Maxillary Implant-assisted Obturators using Digital Image Correlation Analysis

The purpose of the study was to evaluate the stress on the implant and to assess the denture displacement for locator and bar and clip attachment types in implant-assisted obturators. A maxillary edentulous experimental model with a maxillectomy defect was made along with an opposing edentulous mandibular model with self-cure acrylic. Two endosseous implants were placed in the maxillary model. Corresponding obturator complete denture was fabricated for the maxillary model and a complete denture for the mandibular. The attachments were positioned on the implants in maxillary model, and their sleeve/clip was placed on intaglio surface of the dentures. The mounted articulator was placed on a loading apparatus, and force was incrementally applied to it. The strain and displacement for both the attachment types were measured and compared using Digital Image Correlation (DIC). Locator attachment showed the least stress and minimal displacement as compared to bar and clip attachment. The stresses around the implants and displacement of the obturator are affected by the attachment type used. It was found that bar and clip (splinted) showed the maximum stresses around the implant and maximum denture displacement. Locator attachment is the better choice over bar and clip because of its additional retentive features. The advantage of using DIC over the conventional strain gauge analysis is that a full-field data of displacement and strain can be obtained instead of getting a mean value on the small surface where the strain gauge is positioned.

Evaluation of retention and patient satisfaction with implant retained mandibular dentures: A clinical study

Objective The aim of this clinical study was to compare the overall satisfaction and retention values of two types of commonly used attachment systems in implant supported mandibular overdentures. Materials and methods: : Prior to implant installation, conventional complete dentures were fabricated for 22 completely edentulous individuals. Two implants were placed in the canine region following the two-stage flapless implant surgical protocol. After 4 months of healing, patients were randomly allocated into two groups: group 1 received ball and socket attachments and group 2 received bar and clip attachments. Patient satisfaction was assessed by VAS questionnaire and retention values were recorded using custom made testing device attached to a force meter at baseline (at the pick-up visit), three, six and twelve months after implant supported prostheses insertion. Result: The study showed significant superior retention values for bar attachment than ball attachment. Patient’s satisfaction scores showed no significant difference between both type of prostheses throughout the study period; however, patients’ satisfaction rates were improved while retention values were reduced significantly by time. Conclusion: The selection of a specific type of implant attachment for implant supported overdentures is dependent on multiple dentist as well as patient related factors.

Retention of bar clip attachment for mandibular implant overdenture

ObjectivesThe aim of the present study was to evaluate the retention and loss of retention after fatigue testing at different time intervals between two types of bar clip materials (digitally designed PEEK bar clip and regular Nylon bar clip).Materials and methodsAn epoxy model was constructed for a completely edentulous mandible. Two implants were placed according to prosthetically driven implant placement by a computer-guided surgical stent. Bar clips were digitally designed, 3D printed, and pressed into Poly Ether Ether Ketone (PEEK). Pick up of PEEK and nylon clips was performed on the dentures fitting surface using self-cured acrylic resin. Each study group was subjected to an insertion and removal fatigue test simulating 3 years of patient usage. Retention values were recorded using the universal testing machine at initial retention and after 1, 2, and 3 years of simulated usage. For proper sample sizing, 24 models and dentures (12 for each group) were used. An independent sample t-test and repeated measures analysis of variance were used to compare the data.ResultsThere were statistically significant differences in retention between the PEEK and nylon bar clips at the beginning of the experiment (p = 0.000*). But after 3 years of simulated use, there was no significant difference in retention between the test groups (p = 0.055, NS). After 3 years of simulated use, the retention of PEEK clips decreased by − 58.66% recording 17.37 ± 1.07 N, while the retention of nylon clip increased by + 2.99% recording 16.56 ± 0.88 N.ConclusionThe digitally designed PEEK clip showed comparable retention results to the nylon clip after 3 years of simulated use.Clinical relevanceMaintenance of bar attachment with PEEK clip offers a clinical solution after the wear of normal plastic clips, which is a cheap solution that is easily fabricated and picked up into the denture. Digital fabricated PEEK bar retentive inserts can be used in cases of bar attachment wear.

Comparison of Minimally Invasive Mitral Valve Surgery vs Open Mitral Valve Replacement

Objective: To establish the advantages of invasive mitral valve surgery over open heart mitral valve surgery in treating patients with mitral valve pathologies. Material and Methods: A literature search was done on PubMed, google scholar, and Embase using search terms like open ‘invasive mitral valve surgery’, ‘mitral clip’, ‘sternotomy’, and ‘annuloplasty.” The time limit was set to 5 years ago and the language set to English. After searching, a quick screening of the title and abstract was done for relevance. The selected papers were then used in this review. Results: The minimally invasive mitral valve surgery was shown to have significantly greater survival rates across all post-surgical time frames as well as lower short-term mortality rates. Mini MVS was also shown to be more effective in treating infective endocarditis and is a highly impractical operation for patients with left ventricular dysfunction or other cardiomyopathies. The Minimally Invasive Mitral valve surgery (Mini MVS) proved to cause fewer mortalities and clearly showed a lower number of complications; the complications that exist are highly preventable. In addition, the mini MVS is more effective in treating patients with mitral regurgitation. Conclusion: This review confirms that employing the minimally invasive MVS procedure for patients with mitral valve pathologies is more effective than the standard open heart MVS in terms of post-surgery mortalities and hospital stay times. It is also more effective in treating patients with preexisting cardiomyopathies. However, sufficient training should be done to prevent complications from arising. The mitraliclp device should be further developed to prevent complications that arise due to the clip attachment

Comparison of Minimally Invasive Mitral Valve Surgery vs Open Mitral Valve Replacement

Objective: To establish the advantages of invasive mitral valve surgery over open heart mitral valve surgery in treating patients with mitral valve pathologies. Material and Methods: A literature search was done on PubMed, google scholar, and Embase using search terms like open ‘invasive mitral valve surgery’, ‘mitral clip’, ‘sternotomy’, and ‘annuloplasty.” The time limit was set to 5 years ago and the language set to English. After searching, a quick screening of the title and abstract was done for relevance. The selected papers were then used in this review. Results: The minimally invasive mitral valve surgery was shown to have significantly greater survival rates across all post-surgical time frames as well as lower short-term mortality rates. Mini MVS was also shown to be more effective in treating infective endocarditis and is a highly impractical operation for patients with left ventricular dysfunction or other cardiomyopathies. The Minimally Invasive Mitral valve surgery (Mini MVS) proved to cause fewer mortalities and clearly showed a lower number of complications; the complications that exist are highly preventable. In addition, the mini MVS is more effective in treating patients with mitral regurgitation. Conclusion: This review confirms that employing the minimally invasive MVS procedure for patients with mitral valve pathologies is more effective than the standard open heart MVS in terms of post-surgery mortalities and hospital stay times. It is also more effective in treating patients with preexisting cardiomyopathies. However, sufficient training should be done to prevent complications from arising. The mitraliclp device should be further developed to prevent complications that arise due to the clip attachment.

Non-invasive laparoscopic detection of small tumors of the digestive tract using inductive sensors of proximity

The precise location of gastric and colorectal tumors is of paramount importance for the oncological surgeon as it dictates the limits of resection and the extent of lymphadenectomy. However, this task proves sometimes to be very challenging, especially in the laparoscopic setting when the tumors are small, have a soft texture, and do not invade the serosa. In this view, our research team has developed a new instrument adapted to minimally-invasive surgery, and manipulated solely by the operating surgeon which has the potential to locate precisely tumors of the digestive tract. It consists of an inductive proximity sensor and an electronic block encapsulated into an autoclavable stainless-steel cage that works in tandem with an endoscopic hemostatic clip whose structure was modified to increase detectability. By scanning the serosal side of the colon or stomach, the instrument is capable to accurately pinpoint the location of the clip placed previously during diagnostic endoscopy on the normal bowel mucosa, adjacent to the tumor. In the current in-vivo experiments performed on large animals, the modified clips were transported without difficulties to the point of interest and attached to the mucosa of the bowel. Using a laparoscopic approach, the detection rate of this system reached 65% when the sensor scanned the bowel at a speed of 0.3 cm/s, and applying slight pressure on the serosa. This value increased to 95% when the sensor was guided directly on the point of clip attachment. The detection rate dropped sharply when the scanning speed exceeded 1 cm/s and when the sensor-clip distance exceeded the cut-off value of 3 mm. In conclusion, the proposed detection system demonstrated its potential to offer a swift and convenient solution for the digestive laparoscopic surgeons, however its detection range still needs to be improved to render it useful for the clinical setting.

Comparison of retention of two different attachment systems used in implant-supported overdentures

Aim:This study aims to compare the retentive capacity of two attachment systems after manual thermocycling.Settings and Design:In vitro study and Comparative trail.Materials and Methods:An edentulous mandibular Polymethyl Methacrylate model was fabricated to receive the overdentures with the two attachment systems to be compared. Two dental implants were placed in the predetermined right and left mandibular canine regions of the model. A total number of eight overdentures, four per group, were fabricated over the two implants with two attachment systems to be compared; Bar and clip attachment system (Group-1) and Locator attachment system (Group-2). All the overdentures were subjected to 5000 alternating thermal cycles using manual thermocycling. Then the samples were subjected to 100 vertical pulls each in the anterior and posterior regions using a universal testing machine and the mean retentive forces were calculated for each sample in the anterior and posterior regions, respectively.Results:The mean retentive forces after 100 vertical pulls, were calculated and tabulated for each sample in the anterior and posterior regions separately. Then, the cumulative mean of the anterior and the posterior regions were calculated for each group. The cumulative mean retentive forces of both the attachment groups were-Group-1 (Bar and clip attachment system) = 27.87 N ± 4.01 and Group-2 (locator attachment system) = 18.85 N ± 2.50 with a P value of 0.021. This difference was found to be statistically significant.Conclusion:Within the limitations of the present in vitro study, the bar and clip attachment system offered better retention than the locator attachment system.

Effect of Resilient Soft Liner and Clip Attachments on Peri-Implant Tissue in Splinted Mini-Implant Retained Mandibular Overdentures

Effect of Resilient Soft Liner and Clip Attachments on Peri-Implant Tissue in Splinted Mini-Implant Retained Mandibular Overdentures

Retention and Stability Characteristics of Soft-Liner and Clip Attachments Used for Bar/Implant-Assisted Mandibular Overdentures: An In Vitro Study.

To investigate retention and stability characteristics of soft-liner and clip attachments used for bar/implant-assisted mandibular overdentures. Two implants were placed in an edentulous mandibular model. According to the type of bar, presence of cantilevers, and type of attachments, eight groups were tested: (1) Dolder bar with cantilevers and three titanium clips (DCC), (2) Dolder bar with cantilevers and resilient liner attachments (DLC), (3) Dolder bar without cantilevers and one titanium clip (DCWC), (4) Dolder bar without cantilevers and resilient liner attachments (DLWC), (5) Hader bar with cantilevers and three plastic clips (HCC), (6) Hader bar with cantilevers and resilient liner attachments (HLC), (7) Hader bar without cantilevers and one plastic clip (HCWC), and (8) Hader bar without cantilever and resilient liner (HLWC). Axial (retention) and nonaxial (stability during anterior, posterior, and lateral dislodging) forces were evaluated initially and after 540 times of prosthesis insertion and withdrawal. The highest retention and stability forces were observed with HCC, and the lowest forces were recorded with DLWC. The lowest retention and stability after wear was noted with DCWC and HCWC. For the majority of groups, the highest forces were noted with posterior dislodgment, and the lowest forces were observed with lateral dislodgment. The largest retention loss was recorded with DCC and HCC, and the lowest retention loss was noted with HLWC. DLC and HLC showed retention gain. Hader bar with clips and cantilever extensions achieved the highest retention and stability forces after wear simulation, while bars without cantilevers and clips showed the lowest forces. For cantilevered Dolder and Hader bars, clip attachments showed increased retention loss, while soft-liner attachments showed retention gain.

English

The main aim of prosthetic dentistry is restoring the form, function, comfort and appearance of the patient by the placement of a prosthesis replacing the missing teeth and contiguous tissues.1 Various prosthetic options for partially edentulous patients include an interim removable partial denture (RPD) to a cast partial denture, a fixed dental prosthesis (FDP), and a more implant-retained prosthesis. However, FDP and implant-retained prosthesis are not always feasible, particularly in patients with excessive residual ridge resorption and jaw defects due to trauma and / or surgical ablation. In such a situation, a dentist may resort to another option of fixed-RPD prosthesis, to restore the defective hard and soft tissues to achieve natural aesthetics, phonetics, comfort, and better hygiene. This hybrid prosthesis fulfils the objectives of the rehabilitation such as support, stability, and retention characteristics similar to a fixed prosthesis and aesthetics and hygiene maintenance of a removable prosthesis.2,3,4,5 Any prosthesis designed or fabricated should be based on the prosthetic principles of support, stability, retention, and preservation of remaining structures.1 From the patient's perspective, retention is one of the important factors for its acceptability. These retentive options range from simple bar and clip attachments to more sophisticated spark erosion overdentures.6,7 Spark erosion prosthesis is technique sensitive, bulky, and requires expensive equipment.6,7 On the other hand, precision attachments provide better vertical support and stimulation to the underlying tissue through intermittent vertical massage.8 Treatment with a hybrid denture is an affordable choice to fulfil the patient's aesthetic demands along with providing a good prognosis for the prosthesis and preservation of the remaining dentition. This article presents two case reports of prosthodontic rehabilitation of a patient with mandibular defects using an attachment-retained fixed-removable hybrid prosthesis.

Microstrain analysis of implants retained complete mandibular overdenture by using two different attachments (an in vitro study)

Purpose The aim of this work is to evaluate strain analysis of two piece implants retained complete edentulous mandibular overdenture with two different attachment systems bar and clip attachment and extracoronal resilient attachment (ERA + bar) by using strain gauge analysis. Materials and Methods This in vitro strain analysis of implants retained complete mandibular overdenture with two attachments carried out on two completely edentulous mandibular models covered by 2 mm thickness mucosa. Two finished dentures were constructed one denture for each group. Group 1: two implants at canine region with bar attachment. Group 2: two implants at canine region with bar and ERA attachments. Four strain gauges were cemented around each implant, buccal, lingual, mesial, and distal. A 50 N static load was applied on the experimental model in vertical and oblique directions. Strain data of each group was collected tabulated and statically analyzed. Results The result of this study revealed that the difference of microstrain between the two groups was significant as the maximum microstrain recorded was found in group 1 followed by group 2. The oblique forces increase the resulting strain than vertical forces. Conclusion There are different patterns of strain analysis at bone–implant interface between the studied attachment designs, the ERA-bar combination exhibited better strain analysis than bar-clip system

Finite element validation of 3D American football faceguard structural stiffness models

Despite continued efforts to improve American football headgear technology, minimal structural changes have been made to faceguard design in the past 20 years. Although each new helmet system has its own compatible faceguard series, the primary design components have changed little between helmet systems. Additionally, little is known about specific parameters that influence faceguard performance, largely due to the variation inherent in laboratory impact testing. The goal of this study was two-fold: to validate a reverse engineering method for developing a library of faceguard models; and to validate the finite element simulation of three common American football faceguards subject to a quasi-static structural stiffness test. Three common Riddell® Speedflex™ (Des Plaines, IL) faceguard styles were modeled using a novel reverse engineering approach. Within ANSYS® Mechanical™ (ANSYS, Inc., Canonsburg, PA), the faceguards were modeled as stainless steel (elastic modulus = 193 GPa, Poisson’s ratio = 0.31). A displacement of 5 mm was prescribed in the posterior (z) direction. Boundary conditions were applied to accommodate the coronal plane (x, y) translation at clip attachment locations. The computational results correlated to the experimental results with statistical significance ( p value = 0.001). The Nose location was the most reliable with an average percent difference from experimental results of 2.7%, compared to 10.8% and 9.9% at the Mouth and Chin locations, respectively. Many studies utilizing computational models of protective headgear lack reported validation of headgear components. This study has validated the structural stiffness of three common faceguards to be used in future computational analyses. Furthermore, advancements in additive manufacturing technologies have opened the door to increasingly complex faceguard design capabilities; however, little is known about specific parameters that influence faceguard performance. With the models validated in this study, parameterized faceguard models should be used to iterate between design variables and assess the contribution of each variable on faceguard structural stiffness.

Reducing upper digestive bleeding risk in patients treated with direct oral anticoagulants and concomitant infection with Helicobacter pylori.

Direct oral anticoagulants (DOACs) such as apixaban or dabigatran are excellent options in preventing embolic cardiovascular events. Observational studies have shown that gastrointestinal bleeding risks produced by DOACs could be lowered when correcting some host co-factors i.e. Helicobacter pylori (HP) infection. The upper digestive bleeding (UDB) rates in patients with DOAC indication and the usefulness of anti-HP therapy addition were compared. An observational retrospective study was conducted of medical records of 260 patients treated with DOACs, 130 of whom were concomitantly treated for HP infection in accordance with Maastricht V/Florence consensus. The severity of bleeding, the complexity of endoscopic treatment required to stop the bleeding, the re-bleeding rates, the surgical treatment indication and the overall mortality rates were compared between the groups. The risk of UDB was higher in HP-untreated patients in both types of DOACs used (respectively 2.08, 2.02). HP-untreated Forrest Ia/Ib/IIa and IIb DOACs patients had more severe bleedings compared with same class of HP-treated patients (P=0.007/0.005; 0.009/0.006; 0.048/0.005, 0.044/0.049, respectively). Endoscopic treatments such as adrenaline injections combined with metallic clip attachments were more frequently mandatory in HP-untreated DOACs patients for classes Ia/b and IIa (respectively, P=0.000/0.001, P=0.003/0.003). The re-bleeding rates were higher in HP-untreated patients with concomitant DOACs (OR 82.5; 95% CI 30.1-121.7; P=0.005). A history of peptic ulcer or UDB was associated with a 2.9-fold higher risk of UDB in HP-untreated compared with HP-treated patients, slightly increased for dabigatran compared with apixaban (RR 3.06, 2.72, P<0.5, respectively). Surgical intervention and the UDB-related mortality rates were higher in HP-untreated patients (P=0.041/0.044, P=0.007, respectively). HP-eradication treatment and bacterial clearance improve the safety profile of DOACs treatment, especially in fragile patients, in whom the UDB rates can be lowered, and the overall outcome can be enhanced by this combined approach.

The effect of cycling shoes and the shoe-pedal interface on maximal mechanical power output during outdoor sprints

Cyclists and industry professionals believe that cycling shoes with pedal attachment and stiff soles improve performance. However, scientific evidence has demonstrated that cycling shoes have no significant effect on metabolic cost during low-intensity, submaximal, steady-state cycling (50–150 W). Here, we investigated if stiff-soled cycling shoes combined with clip-in pedals provide benefits relevant to sprint cycling. We measured the mechanical power outputs and velocities of twelve healthy male cyclists during maximal sprint cycling. Participants rode outdoors on a paved asphalt road with a steady, uphill gradient of 4.9%. Each participant completed sets of three 100-metre cycling sprints in three conditions: (1) running shoes with flat pedals (no pedal attachment + flexible soles), (2) running shoes with classic aluminium quill pedals with toe clips and straps (pedal attachment + flexible soles), and (3) cycling shoes with clip-in pedals (pedal attachment + stiff soles). When using the running shoes, the toe clip attachment increased maximum sprint power by 9.7 ± 8.7% (p = 1.7E − 03). Maximum sprint power was 16.6 ± 10.2% (p = 3.25E − 06) greater for the stiff-soled cycling shoes combined with clip-in pedals compared to the flexible running shoes with toe clips condition, presumably due to the greater sole stiffness of the cycling shoes. Shoe-pedal attachment and stiff soles each positively improve cycling performance during high-power, uphill sprints.

Finite element analysis of stress distribution around short and long implants in mandibular overdenture treatment

Optimal stress distribution around implants plays an important role in the success of mandibular overdentures. This study sought to assess the pattern of stress distribution around short (6 mm) and long (10 mm) implants in mandibular two implant-supported overdentures using finite element analysis (FEA). In this descriptive and experimental study two implant-supported overdenture models with bar and clip attachment system on an edentulous mandible were used. Two vertical implants were connected by a bar. The implant length was 6 mm (short implant) in the first and 10 mm (long implant) in the second model. Vertical loads (35, 65, and 100 N) were applied bilaterally to the second molar area. In another analysis, vertical loads of 43.3 N and 21.6 N were applied to working and nonworking sides, respectively, at the second molar area. Furthermore, the lateral force (17.5 N) was applied to the canine area of overdenture. The stress distribution pattern around implants was analyzed using FEA. The maximum von Mises stress was 57, 106, and 164 MPa around short implants and 64, 118, and 172 MPa around long implants following the application of 35, 65, and 100 N bilateral forces, respectively. Application of bilateral loads created 87 and 65 MPa stress around working and nonworking short implants, respectively; while these values were reported to be 92 and 76 MPa for long implants at the working and nonworking sides, respectively. Increasing the vertical loads increased the level of stress distributed around the implants; however, no considerable differences were noted between long and short implants for similar forces. Following unequal load application, the stress in the working side bone was more than that in the nonworking side, but no major differences were noted in similar areas around long and short implants. Following lateral load application, the stress distributed in the peri-implant bone at the force side was more than that in the opposite side. In similar areas, no notable differences were observed between long and short implants regarding the maximum stress values. Using implants with different lengths in mandibular overdenture caused no major changes in stress distribution in peri-implant bone; short implants were somehow comparable to long implants.

Long-term assessment of over-the-scope clip (OTSC) behavior after gastric application

Background: The aim of this study was to assess the long-term behavior of the over-the-scope clip (OTSC) after gastric application.Material and methods: A database of all patients who had OTSC placement with regular follow-up at a tertiary hospital between November 2013 and September 2016 was retrospectively analyzed. The incidence, time, and related adverse events of clip attachment and detachment were recorded. The relationship between the position of the clip and detachment was assessed by Fisher's exact test.Results: Seventy-two patients who had gastric OTSC placement due to iatrogenic perforations by endoscopic interventions were included in the study. The overall incidence of clip detachment was 27.8% (20/72). Fisher's exact test confirmed a significant association between clip detachment rate and clip position (p = .005): cardia 50% (3/6); gastric fundus 13.2% (5/38); gastric body 75% (9/16); and gastric antrum 25% (3/12). Except for one patient (5%; 1/20) who experienced minor gastric hemorrhage, there were no complications related to spontaneous clip detachment. There was no delayed bleeding, perforation, or obstruction due to clips staying in place in the long-term.Conclusions: Long-term gastric clip attachment appears to be safe even if spontaneous detachment occurs.

Retention and patient satisfaction with bar-clip, ball and socket and kerator attachments in mandibular implant overdenture treatment: An in vivo study.

Aim:The aim of this in vivo study was to evaluate and compare the retention and patient satisfaction in implant supported mandibular overdenture with three different attachment system.Materials and Methods:After evaluation of prosthetic space, fifteen edentulous subjects received two implants in the inter-foramina region of the mandible and were divided into 3 groups with 5 subjects each, delayed loading protocol was followed in all the patients. The retention force and satisfaction level with the attachments at baseline and after 6 months was measured in a standardised way using retentive device and VAS questionnaire. The study was based on evaluation of retention and patient satisfaction. 15 subjects were included in the study. The results obtained were statistically analyzed using one-way ANOVA test, and multiple comparisons were carried out using the Bonferroni tests.Results:At the end of six months, the retention force and satisfaction level was higher in Group 3 (Kerator attachment) as compared to Group 1 (ball and socket attachment) and Group 2 (bar and clip attachment) and patient satisfaction was equal in groups 1, 2 and 3 but the total number of interventions is significantly higher in the attachment bar. Analysis of variance with repeated measures showed significant differences in retention force among the three attachment types.Conclusion:(1) Group 3 (kerator attachment) exhibit higher retentive capacities than Group 1 (ball and socket attachment) and Group 2 (bar and clip attachment). (2) patient satisfaction was higher in Group 3 (Kerator attachment) in compare to Group 1 (ball and socket attachment) and Group 2 (bar and clip attachment).

Hard and soft-tissue evaluation of bar-clip, ball-socket, and kerator attachments in mandibular implant overdenture treatment: An in vivo study.

Aim:The aim of this in vivo study was to evaluate and compare the soft and hard tissue changes in implant supported mandibular overdenture with three different attachment system.Settings and Design:In vivo – observation study.Materials and Methods:After evaluation of prosthetic space, fifteen edentulous subjects received two implants in the inter-foramina region of the mandible and were divided into 3 groups with 5 subjects each, delayed loading protocol was followed in all the patients. The crestal bone loss, modified sulcular bleeding index, plaque index values were evaluate with the attachments at baseline and after 6 months was measured in a standardised way.Statistical Analysis Used:Oneway ANOVA test and post hoc Bonferroni multiple test.Results:At the end of six months modified sulcular bleeding index and plaque index values was higher in Group 2 (bar and clip attachment) as compared to Group 1 (ball and socket attachment) and Group 3 (Kerator attachment) and crestal bone loss was equal in groups 1, 2 and 3. Analysis of variance with repeated measures showed significant differences in modified sulcular bleeding index and plaque index among the three attachment types.Conclusion:(1) Group 2 (bar-and-clip attachment) exhibited higher Modified Sulcular Bleeding Index and Plaque Index values than Group 1 (ball-and-socket attachment) and Group 3 (kerator attachment). (2) Crestal bone loss was equal in Group 1 (ball-and-socket attachment), Group 2 (bar-and-clip attachment), and Group 3 (kerator attachment).

Effect of Different Bar Attachment and Clip Materials on Retention Force for Mandibular Implant Supported Overdentures (An Invitro Study)

Objective: to evaluate the effect of bar and clip attachment systems with different materials on retention forces for two implant supported mandibular over dentures after wear simulation. Materials and methods: An edentulous mandibular model was constructed incorporating 2 parallel implants placed in the canine regions. Attachments were embedded in ametal-reinforced experimental over denture designed to be dislodged from the model by a universaltesting machine. Tensile dislodging force was applied to the overdenture at a cross-head speed of 50 mm/min. Four over dentures were constructed for the attachment systems. The attachments evaluated were metal bar with clip from polyoxymethylene (POM), metal bar with clip from polyetheretherketon (PEEK), (PEEK) bar with (POM) clip and(PEEK) barwith (PEEK) clip. Peak load-to-dislodgement was measured. Retention strength values (N) were recorded initially and after 270, 540, 810 and 1080 cycles of insertion and removal simulating 0, 3, 6, 9 and 12 months of denture using repictively. Repeated measure ANOVA was used to compare between more than two groups for dependent samples while One-way ANOVA was used to compare between more than two groups for independent samples. The significance level was set at P ≤ 0.05. Statistical analysis was performed with IBM® SPSS® Statistics Version 20 for Windows. Results: A statistically significant difference was found between (Metal bar and POM clip), (Metal bar and PEEK clip), (PEEK bar and POM clip) and (PEEK bar and PEEK clip) where (p≤0.001). The highest mean value of retention was found in (PEEK bar and PEEK clip) followed by (Metal bar and PEEK clip) and (PEEK bar and POM clip) while the least mean value of retention was found in (Metal bar and POM clip).Conclusion: Attachments generally demonstrated significantly decreased retention strength values as the cycle’s number increased. POM as well as PEEK materials may fulfill the requirements of retentive clips on metal or PEEK bars. The invitro performance of retentive clips made of PEEK is superior to those made of POM.