Overdenture Attachments Research Articles

Effect of Simulated Mastication on the Retention of Locator Attachments for Implant-Supported Overdentures: An In Vitro Pilot Study.

Limited information is currently available relative to the effect of masticatory loads on the retentive properties of Locator attachments. The aims of this in vitro study were to assess and compare the effect of simulated mastication on the retention of white, pink, and blue Locator inserts for overdentures retained by 2 implants. Thirty specimens simulating a nonanatomic edentulous flat ridge with two implants and an overdenture were divided into 3 groups according to the color of the fitted insert: transparent clear group (n = 10), pink group (n = 10), and blue group (n = 10). Retention forces were measured in an axial direction initially and after 100,000 cycles of simulated masticatory loads. One-way ANOVA followed by Tukey's post hoc tests were used to compare retention values and percentage retention loss between the 3 groups with significance set at p = 0.05. The 3 groups presented significant differences in retention at baseline (9.95 ± 1.91 N, 15.43 ± 4.08 N, and 41.73 ± 9.29 N for the blue, pink, and clear groups, respectively) and after simulated mastication (6.37 ± 2.64 N, 14.00 ± 3.89 N, 38.20 ± 5.11 N for the blue, pink, and clear groups, respectively). Within the same group, cyclic loading did not significantly affect retention in the clear and pink groups, while the blue inserts showed a significant retention loss (-37%) after loading. The results suggest that short-term simulated mastication affects the extra-light blue inserts but not the more-retentive inserts.

MAGNET VERSUS OLS ATTACHMENTS FOR IMPLANT OVERDENTURES: A STRESS ANALYSIS STUDY

Objectives: to compare between the microstrains transmitted to the implants with magnetic and OLS attachments in 2-implant overdentures. Methodology: two dummy implants 3.7 mm in diameter and 12mm in length were placed in an acrylic resin model resembling a completely edentulous mandible. Attachment pick up was done for the magnetic attachment followed by loading and measurement. Four Strain gauges were used to measure microstrains around the implants during unilateral and bilateral loading using a universal testing machine and a multi-channel strain meter. The procedure was repeated for the OLS attachment. Measurements were tabulated and statistically analyzed. Results: loading sides demonstrated significantly higher microstrains around the implants with the two attachments than non-loading sides. OLS attachment showed significantly higher microstrains than magnetic attachment for both loading and non-loading sides during unilateral loading. During bilateral loading, there was no significant difference between the two attachments. Conclusion: implant overdentures retained by magnetic attachments transmit less stresses to the implants than OLS attachments with PEEK retentive matrices during unilateral loading. During bilateral loading, the stresses transmitted by the two attachments were comparable.

Effect of implant- and occlusal load location on stress distribution in Locator attachments of mandibular overdenture. A finite element study

PURPOSEThe aim of this study is to evaluate and compare the stress distribution in Locator attachments in mandibular two-implant overdentures according to implant locations and different loading conditions.MATERIALS AND METHODSFour three-dimensional finite element models were created, simulating two osseointegrated implants in the mandible to support two Locator attachments and an overdenture. The models simulated an overdenture with implants located in the position of the level of lateral incisors, canines, second premolars, and crossed implant. A 150 N vertical unilateral and bilateral load was applied at different locations and 40 N was also applied when combined with anterior load at the midline. Data for von Mises stresses in the abutment (matrix) of the attachment and the plastic insert (patrix) of the attachment were produced numerically, color-coded, and compared between the models for attachments and loading conditions.RESULTSRegardless of the load, the greatest stress values were recorded in the overdenture attachments with implants at lateral incisor locations. In all models and load conditions, the attachment abutment (matrix) withstood a much greater stress than the insert plastic (patrix). Regardless of the model, when a unilateral load was applied, the load side Locator attachments recorded a much higher stress compared to the contralateral side. However, with load bilateral posterior alone or combined at midline load, the stress distribution was more symmetrical. The stress is distributed primarily in the occlusal and lateral surface of the insert plastic patrix and threadless area of the abutment (matrix).CONCLUSIONThe overdenture model with lateral incisor level implants is the worst design in terms of biomechanical environment for the attachment components. The bilateral load in general favors a more uniform stress distribution in both attachments compared to a much greater stress registered with unilateral load in the load side attachments. Regardless of the implant positions and the occlusal load application site, the stress transferred to the insert plastic is much lower than that registered in the abutment.

Effect of Interimplant Distance and Cyclic Loading on the Retention of Overdenture Attachments

The purpose of this in vitro study was to investigate the effect of interimplant distance and cyclic loading on the retention of two locator attachment systems. A total of 72 acrylic resin blocks were fabricated and divided into six groups of six pairs each. Locators of DIO and 3i implant systems were positioned on analogs in three different interimplant distances (19, 23, and 29 mm). The blocks were attached to a universal testing machine, and 1,440 dislodging cycles by the force of 136 N were applied. After 0, 120, 360, 720, and 1,440 cycles, the retention was recorded. Three-way analysis of variance (ANOVA) was used to test for differences in retention between the various combinations of the locator, interimplant distance, and cyclic loadings. Interimplant distance was significantly associated with retention, independent of the locator system used, and dislodge-ment force cycles. Mean retention was significantly higher under the 3i system relative to the DIO system (p < 0.0001). This association varied with both interimplant distance (p > 0.0001) and dislodgement force (p < 0.0001) as well as across the various combinations of distance and cycle (p < 0.0001). Interimplant distances could affect the initial retention of locator attachments. There was little difference in retention between distances of 23 and 29 mm across all cycles when both locator systems were combined. Distance of 23 mm was associated with superior retention in the DIO system. With regard to the speed of retention decrease, the 23 mm distance was associated with better performance. Interimplant distance could play a significant role in overdenture retention with locator attachments.

One-Piece Implant-Retained Mandibular Overdentures By Pre-Fabricated Titanium Telescopic Attachments and Frictional Varnish: A Two-Year Prospective Study.

Clinical efficiency of one-piece screw-type implants with telescopic were attachments evaluated in this study. Twenty-four patients received a mandibular implant-supported overdenture and maxillary complete denture. Ninety-six one-piece implants were inserted in the inter-foraminal area. Implants were immediately loaded with an implant-retained overdenture and telescopic attachments which had frictional retention elements. There was 0.25±0.24 mm, 0.32±0.25 mm, 0.43±0.30 mm, 0.61±0.30 mm and of bone resorption after 3, 6, 12 and 24 months, respectively. The need to activate the frictional retention was the most common complication. Treatment outcomes for prefabricated telescopic retained overdentures on one-piece implants are similar to that obtained in cases of delayed loading.

The Amount of Wear in Attachment of Implant-Supported Overdentures in Mandible

Background and objectives: One of the simplest and cheapest attachments for overdentures, is the ball-type attachment, however, keeping it during the first year of prosthesis delivery and after that is one of the main concerns of dentists. The present study aimed to assess the wear of matrix in overdentures attachment supported by one, two and three implants in the mandible. Materials and methods: Thirty edentulous patients were randomly divided into three groups: the first group received a single implant in the midline of the lower mandible, the second group two implants in areas B and D, and the third group three implants in areas B, C, and D. The attachment used in patients’ prosthetic with single and two implants was O-ball/ring attachment and for patients with three implants, the treatment plan was ball bar-supported attachments. After placing the new matrix implant for each patient and obtaining their consent, the matrix wear was measured with CMM (Coordinate Measuring Machine) device. To compare matrix wear after six months and one year, measurements were repeated. Data analysis, using ANOVA and multiple comparisons was down by Tukey Test. variance with repeated measures and Tukey test were used to compare the groups two-by-two. P.value less than 0.05 was set statistical significant. SPSS 16 software was used for data analysis. Results: The data obtained from the CMM device showed that the lowest mean matrix wear in the maximum single implant and maximum mean were in group two. Conclusion: Both time and the number of implants had a significant effect on the wear of the O-ring.

Association Between Peri-implant Bone Morphology and Marginal Bone Loss: A Retrospective Study on Implant-Supported Mandibular Overdentures.

The present study aimed to explore the association between marginal bone loss and type of peri-implant bony defect determined using a new peri-implant bony defect classification system. A total of 110 patients with implant-supported mandibular overdentures were involved. Clinical information was collected, including gender, age, smoking habit, and the overdenture attachment system used. Peri-implant bony defect types and marginal distances (ie, distance between the marginal bone level and the top of the implant shoulder) of all sites were identified on panoramic radiographs by a single experienced observer. The associations between marginal distance and peri-implant bony defect type, gender, age, smoking habit, attachment system, and time after implantation were investigated using marginal generalized linear models and regression analysis. A total of 83 participants were included in the final sample with a total of 224 implants involving 3,124 implant sites. The mean observation time was 10.7 years. All peri-implant bony defect types except Type 5 (slit-like) were significantly related to marginal distance in all models (P < .01). Smoking and time after implantation were significantly related to marginal distance while gender, age, and the overdenture attachment system used were not. The peri-implant bony defect type, determined using the new classification system, is associated with the extent of marginal bone loss.

Retentive Properties of O-Ring and Locator Attachments for Implant-Retained Maxillary Overdentures: An In Vitro Study.

To evaluate and compare retentive properties of O-ring and Locator attachments for implant-retained maxillary overdentures. Four implant analogs were inserted in canine and second premolar areas of an acrylic edentulous maxillary model. A metal-reinforced experimental acrylic overdenture was constructed and connected to the analogs using either O-ring (group I) or Locator (group II) attachments. Locators were divided into 3 subgroups according the degree of retention of the patrix nylon insert: Locator extra-light retention (group IIa), Locator light retention (group IIb), and Locator medium retention (group IIc). Vertical and oblique (lateral, anterior, and posterior) dislodging forces were measured at the beginning of the study (initial retention) and after 540 cycles of denture insertion and removal (final retention). For vertical, lateral, and anterior dislodging, group IIc recorded the highest initial and final retention, and group I recorded the lowest retention. For posterior dislodging, group I recorded the highest retention, and group IIa recorded the lowest retention. For group II, vertical dislodging recorded the highest initial and final retention, and lateral dislodging recorded the lowest retention. For group I, posterior dislodging recorded the highest initial and final retention, and lateral dislodging recorded the lowest retention. For all dislodging forces (except posterior dislodging), the highest retention loss was recorded in group I, and the lowest retention loss was recorded in group IIa. Locator medium attachment was associated with favorable retention during axial (vertical) and nonaxial (anterior and lateral) dislodging compared to other types of Locator inserts and O-ring attachments after a simulated 6-month period of overdenture use.

Surface roughness and adaptation of different materials to secure implant attachment housings

Statement of problemVarious materials are available to secure implant attachment housings in overdentures. Surface roughness and the adaptation of these materials to the denture base and the housings may increase the microcracks and bacterial adhesion at the interfaces in the long term. The surface characteristics of the interface between the denture base orientation material and the attachment housing have not been extensively studied. PurposeThe purpose of this in vitro study was to evaluate the surface roughness and the adaptation of 5 different housing orientation materials to the housings and the denture base. Material and methodsFifty-five poly(methyl methacrylate) (PMMA) specimens (15 mm in diameter and 4 mm in height) were prepared with a clearance inside to allow the insertion of overdenture housings. Five different materials were used for housing orientation (Quick Up, Ufi Gel Hard, Tokuyama Rebase II Fast, Meliodent, and Paladent). The specimens were thermocycled 5000 times between 5°C and 55°C. The surface roughness (Ra values) of the specimens was measured with a noncontact profilometer. Scanning electron images were made in order to inspect the PMMA-orientation material-housing interfaces. The Kruskal-Wallis test was used to investigate the differences between the surface roughness values of the orientation materials, and the Iman-Conover test was used for pairwise comparisons (α=.05). ResultsThe surface roughness values significantly differed between Quick up and Ufi Gel orientation materials only, and Quick up had smaller surface roughness values than Ufi Gel (P=.009). Microcracks were observed among the groups only at the junction of the orientation material and the housing after thermocycling. ConclusionsUfi Gel Hard showed the roughest surfaces around the overdenture attachment housings. The adaptation between the orientation material and the housing may deteriorate, and increased surface roughness and microcrack formation may be seen around the housings.

Compromised residual dentition used as abutments for improving stability and retention of complete overdentures in a patient with cerebral palsy- a case report

Cerebral palsy is a common term for a group of disorders, characterized with features of a non-progressive brain injury or a lesion acquired during early childhood. A case of a 58-year-old female patient with medical history of cerebral palsy and hypertension is reported. After extraction of all hopeless teeth, the remaining teeth on both jaws underwent periodontal and endodontic treatment because they were used as ball attachments for tooth-supported conventional complete overdentures. The advantages of this treatment plan are maintaining the integrity of the residual ridges, improved stability and retention of the dentures due to usage of compromised residual dentition. This provides the patient with easier and shorter adaptation period as well as with better mastication, speech and esthetics. Even if the abutment teeth are lost due to insufficient oral hygiene and periodontal disease the overdentures could be relined and used as conventional complete dentures.

COMPARATIVE STUDY BETWEEN TWO TYPES OF ATTACHMENTS USED FOR ROOT-SUPPORTED OVERDENTURE

INTRODUCTION: The incorporation of attachments in overdentures into everyday dental practice will open up another dimension in dental treatment planning and patient satisfaction. Teeth that might be considered for extraction may be considered as long or short term alternatives to implant or total edentulousness. Some teeth are maintained to support and/or retain the prosthesis and therefore, maximizing prosthesis stability, besides preserving proprioception of the periodontal ligament and reducing bone loss. Tooth-supported overdentures can be retained with attachments and can improve both retention and stability while simultaneously reducing alveolar bone resorption. They may also be more cost-effective and maintain more dental proprioception than implant-supported overdentures. OBJECTIVES: To compare clinically and radiographically between flex pivot (precision attachment with flexible male sphere) and castable pivot (semiprecision attachment) used for root-supported overdenture.MATERIALS AND METHOD: This randomized parallel controlled clinical study was conducted on twelve patients having bilateral mandibular single rooted teeth; canines or first premolars. Those were divided into two groups of six subjects. Group A (study group) each of six patients received flex pivots (precision attachment with flexible male sphere) bilaterally as test group. Group B (control group) six patients received castable pivots (semiprecision attachment) bilaterally as control group.RESULTS: When the data of changes in the clinical and radiographic parameters of periodontal status over a 6 months period were compared at immediate post-treatment, 1, 3, and 6 months intervals relative to type of attachment, the findings revealed there were no significant differences among precision attachment group in most of the mean values, while the opposite was shown in semiprecision attachment.CONCLUSIONS: Precision attachment with flex pivot was associated with more superior clinical periodontal parameters than precision attachment, and it is more biocompatible, hygienic, and maintaining healthy, stable periodontal soft tissue and crestal alveolar bone level.

An in vitro comparative study to evaluate the retention of different attachment systems used in implant-retained overdentures.

Aim:The aim of this in vitro study was to compare the change in the retentive force and removal torque of three attachment systems during simulation of insertion-removal cycles.Methodology:Edentulous mandibular models were made with heat-cured polymethyl methacrylate resin. Two implant replicas (CMI), of 3.75 mm diameter and 10 mm length, were placed in the intraforaminal region. Acrylic resin mandibular overdentures were fabricated and provision was made to receive three different overdenture attachment systems, prefabricated ball/o-ring attachment (Lifecare Biosystems, Thane, India), Hader bar and clip attachment (Sterngold, Attleboro, MA), and Locator® implant overdenture attachment stud type (Zest Anchors LLC, USA). Using a universal testing machine, each of the models were subjected to 100 pulls each to dislodge the overdenture from the acrylic model, and the force values as indicated on the digital indicator were tabulated both before and after thermocycling (AT).Statistical Analysis Used:Statistical analysis comprised Kolmogorov–Smirnov test, Friedman test, and Wilcoxon signed ranks test.Results:The statistical model revealed a significantly different behavior of the attachment systems both before and AT. The ball/o-ring and bar attachments developed higher retentive force as compared to the locator attachment. The bar and clip attachment exhibited the highest peak as well as the highest mean retention force at the end of the study. The Locator® attachment showed a decrease in retentive potential after an early peak.Conclusions and Clinical Implications:The ball/o-ring and bar and clip attachments exhibit higher retentive capacities than the Locator® attachment over time.

In vitro retention force measurement for three different attachment systems for implant-retained overdenture.

Aim:The aim of this study is to compare the retention force of three different types of overdenture attachment systems used in implant-retained mandibular complete overdentures.Materials and Methods:Twenty-one similar acrylic resin blocks were prepared and divided into three study groups: Group A (snap attachment) - 10 specimens, Group B (locator attachment) - 1 specimen, and Group C (syncone attachment) - 10 specimens. A single rectangular heat cure acrylic resin block with two implant analogs 22 mm apart was used with all specimens. Each specimen was subjected to 5500 cycles of insertion and removal in the presence of artificial saliva, representing 5 years of usage. Retention was measured three times for each specimen using universal testing machine. Data were analyzed using one-way and two-way analysis of variance at 95% level of confidence.Results:Locator attachment group (Group B) showed the greatest retention level throughout the study, followed by snap attachment (Group A), and syncone attachment (Group C) showed the lowest retention level.Conclusion:Regardless of the initial retention level of overdenture attachment, gradual loss of retention values is inevitable. However, the rate of retention loss in overdenture attachments is higher in types which comprised plastic parts within their components, rather than those totally made up of noble metals.

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

PURPOSEThis in vitro study investigated and compared the durability and retention of three types of attachments.MATERIALS AND METHODSThree commercially available attachments were investigated: Clix®, Dalbo-Plus® and Locator®. 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℃. The abutments were placed at angulations of 0°, 10° and 20°. The retention force was recorded at the beginning and after 540, 1080, 2160, 3240, 4320 and 5400 insertion-removal cycles.RESULTSThe 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).CONCLUSIONGreater 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.

Mandibular Denture Base Deformation with Locator and Ball Attachments of Implant-Retained Overdentures.

The aim of this in vitro study was to evaluate and compare mandibular denture base deformation between ball and Locator attachments of implant-retained overdentures. An experimental acrylic model covered with resilient silicone mucosal simulation was constructed. Two laboratory implants were placed in the canine areas of the model. Two duplicate experimental overdentures were constructed and connected to the implants with either ball (GI) or Locator (GII) attachments. To measure overdenture strain around the attachments, 3 strain gauges were attached to the lingual polished surface of the overdentures opposite to the right implant (loading side) 2 mm above the attachment level (Ch1), at the attachment level (Ch2), and 2 mm below the attachment level (Ch3). Another 3 gauges were bonded opposite to the left implant (non-loading side) in the same manner (Ch6, Ch7, and Ch8). To measure strain at the midline of the overdentures, two strain gauges were attached in the midline at 5 mm intervals (Ch4 and Ch5). A universal testing device was used to deliver vertical static load of 50 N unilaterally and bilaterally to the first molar area to measure strain using a multi-channel digital strain meter. During bilateral load application, GII recorded higher compressive strains than GI at the majority of channels. During unilateral load application, GI recorded higher tensile strains at Ch1, Ch2, and Ch3, and GII recorded higher strains than GI at Ch6, Ch7, and Ch8. During bilateral loading the highest strain was concentrated at Ch5 for both groups. During unilateral loading, the highest strain was concentrated at Ch2 for GI, and at Ch5 for GII. Ball attachments for implant-retained overdentures were associated with significant mandibular denture base deformation over the implants compared to Locator attachments. Therefore, denture base reinforcement may be recommended with ball attachmentz to increase fracture resistance of the base.

Design modification in overdentures with precision attachments in a case of reduced vertical dimension

Overdentures is a preferred treatment option in patients who have to go for extraction of the remaining teeth for fabrication of complete dentures. The teeth which are preserved, play a vital role by improvement of crown root ratio, provide proprioception, decrease the rate of resorption, and improve support to the denture. Rehabilitation using overdentures is a widely accepted preventive approach due to its ease of fabrication and the successful prognosis. An over denture is a preventive prosthodontic concept with a multidisciplinary approach involving periodontic, endodontic, and prosthodontic intervention. An overdenture improves retention, stability, maintains proprioception, prevents residual ridge resorption, and improves patient satisfaction. This is a case report of a patient with few remaining teeth, successfully treated with Preci-Sagix (Ceka attachments Preci-line, Belgium) overdenture attachments.

Biomaterial aspects: A key factor in the longevity of implant overdenture attachment systems.

Background:New attachment systems are released for mandibular two-implant overdentures often without evidence-based support. Biomaterial aspects are now the parameters considered when choosing the appropriate attachment. Studies regarding their properties remain scarce.Purpose:The purpose of this review was to help the clinician in selrcting the most adapted stud attachments according evidence-based dentistry.Materials and Methods:An electronic search was conducted using specific databases (PubMed, Medline, and Elsevier libraries). Peer-reviewed articles published in English up to July 2014 were identified. Emphasis was given on the biomaterial aspects and technical complications. No hand search was added.Results:The electronic search generated 115 full-text papers, of which 84 papers were included in the review. The majority were clinical and in vitro studies. Some review articles were also considered. Papers reported survival and failures of overdenture connection systems. Emphasis was laid on attachment deformation.Conclusion:Implant overdentures long-term follow-up studies may provide useful guidelines for the clinician in selecting the type of attachment system and overdenture design. Locator attachments are more and more used, with lesser complications reported.

Biomechanical Analysis of Implant Assisted-Overdentures with Variations in the Attachments Systems

The aim of this study was to assess the stress patterns on the peri-implant zone and residual alveolar ridge in different overdenture attachment system designs by the photoelasticity method. Four attachments systems were tested: O-ring, ERA, Bar-clip, and Bar-clip/O-ring association. The prostheses were loaded with 100 N in five pre-determined points and the photoelastic model was evaluated by a circular polariscope. The anterior load, O-ring, and ERA showed better stress distribution in relation to the bars systems, which presented stress levels surrounding implants. The molar load, Bar-clip/O-ring association, presented the biggest stress concentration on the peri-implant region in relation to the others. When the second molar was loaded, there was a concentration of stress in the alveolar ridge in all situations analyzed. Within the limitation of this “in vitro” study, it could be concluded that there were biomechanical differences among the attachments systems analyzed, principally between isolated and the bars systems. The O-ring showed better stress distribution and the Bar-clip/O-ring showed higher stress concentration.

The influence of momentary retention forces on patient satisfaction and quality of life of two-implant-retained mandibular overdenture wearers.

The purpose of this study was to assess the influence of momentary retention forces on patient satisfaction and quality of life of two-implant-retained mandibular overdenture wearers. Edentulous patients who had been rehabilitated with two-implant-supported mandibular overdentures with single attachments and maxillary complete dentures at a university clinic were included in this study. The overdenture attachments were either ball or locator attachments. All the patients completed the Turkish version of the Oral Health Impact Profile-14 (OHIP-14) and the visual analog scale (VAS) satisfaction questionnaires. Momentary retention forces of the overdentures were measured using a custom-made dynamic testing machine. Fifty-five patients were included in this study. No statistically significant association was detected between momentary retention forces and VAS scores (P > .05), but higher retention forces presented significantly better quality of life scores in the social disability and handicap domains of OHIP-14 (P < .05). Within the limitations of this clinical study, it may be presumed that although higher instant retention force of an implant-retained overdenture provides better quality of life, it does not affect patient satisfaction.

Retentive characteristics of a vinylpolysiloxane overdenture attachment system.

Numerous different attachments are used to retain overdentures on implants. The purpose of this study was to evaluate a new chairside attachment system based on polyvinylsiloxane (PVS). A total of 250 specimens were fabricated (n = 10) to measure the retention force (RF) in dependence of the following parameters: fatigue (after 100, 200, 500, 1,000, and 5,000cycles of dislodging), thermal undulation (10,000cycles between 5 and 55°C), implant angulation (0°, 5°, and 10°), and disinfection (three different agents). Three different PVS materials (shore hardness (SH), SH25, SH50, and SH65) were evaluated; locator attachments (LR blue) served as controls. Data were imported into a statistical program and analyzed at a 5% level of significance. Initial RFs were dependent on the shore hardness (p ≤ 0.001, ANOVA). No changes in RFs were observed for PVS groups after repeated dislodging and thermal undulation. Locator attachments revealed a significant decrease in retention force of up to 58% (p ≤ 0.001, Fig.3). No significant changes in RFs were induced by implant angulation. Retention force was decreased in some PVS groups after storage in disinfection solution. Polyvinylsiloxane attachments provide an alternative to locator attachments, exhibiting better stability of the retention force. The presented directly fabricated chairside attachment system represents RFs superior to existing attachment systems after artificial aging.