Ball Attachment System Research Articles

A comparative evaluation of retention capacity of different dental implant supported overdenture attachment systems- An in vitro study

The most common way to treat full edentulism is with a complete denture. In the mandible as opposed to the maxilla, there is greater worry over the durability and retention of a traditional complete denture. The mandibular arch's decreased surface area for support and retention is the main cause of this. For a fully edentulous mandible, implant-supported overdentures are a reliable course of treatment.This in-vitro study aimed at comparing the retentive capacity of Ball, Locator and OT Equator Implant supported overdenture attachment system when subjected to 14600 cycles of insertion and de-insertion.Fifteen mandibular dentures were fabricated with heat polymerized polymethyl methacrylate resin to test the retentive capacity of Ball, Locator and OT Equator attachment system. Metal housing with retentive nylon caps were picked up in all the sample using cold cure acrylic resin. The samples were subjected to fatigue testing and only monodirectional force was applied. Ball, Locator and OT Equator attachment system sample were subjected to 14,600 insertion/ de insertion cycle on Universal Testing Machine and data was recorded and statistical analysis was done. All the three groups showed significant differences. The retentive capacity of the Ball attachments lasts longer than that of the Locator and Equator attachments. After ten years of use, All three systems continue to have clinically acceptable retention.

Retention loss and wear assessment of three attachment systems for implant retained-mandibular overdentures: An in vitro study

BackgroundThe stud-shaped attachment systems (AS) with different shape designs (ball, cylindrical, conical) and materials (metallic, plastic, or a combination of both) are commonly used to provide better retention and stability in implant-retained mandibular overdentures (IRMO). PurposeThe purpose of the present study was to evaluate and compare the retention loss and the wear (patterns, location, material loss) of three resilient unsplinted AS: a well-established ball attachment system (BAS) and two more recent cylindrical attachment systems (CAS), Locator R-Tx® and Novaloc®. Materials and methodsThe implants, their corresponding abutments, the color-coded or position-coded retention devices (RD), the matrix metal housing were incorporated within CAD/CAM resin blocks and cyclically loaded with 19.6 N along the implant axis in a chewing machine to simulate 10,000 insertion-removal cycles (IRC). At cycle 10, 100, 1,000, 5,000, and 10,000, the retention force was measured using a universal testing machine. The wear was qualitatively examined using a binocular magnifier for both systems, and quantitatively assessed from micro-computed tomography acquisitions for CAS. Material loss exceeding 50 μm was considered significant. ResultsThe three AS showed different retentive behavior along time. All the Locator R-Tx® RD lost more than 50 % of their retention after 10,000 IRC. The retention of the Ball System slightly varied over time, the final retention loss in Bmed and Bmax groups being lower than 25 % of the initial retention. Wear was located at the tip of their gold RD and at the equator area of their ball abutment. For Locator R-Tx®, the more retentive the plastic RD, the greater its wear and retention loss. Only Novaloc® maintained a stable retention with even a slight tendency to increase and showed a negligible wear. Implant abutments of the CAS showed no significant wear. ConclusionAfter 10,000 IRC, corresponding to approximately 5-years clinical use, almost all RD provided retention force over 5 N, which could be sufficient to maintain satisfaction in most of the patients. The retention loss observed most prominently for the Locator R-Tx®, then for the Ball System, seemed to correlate with the wear observed on their RD. The practitioner may expect less RD maintenance with the Novaloc® stable retention overtime.

Initial retention force of three attachment systems for implant retained-mandibular overdentures: An in vitro study.

To evaluate and compare the initial retention force of three resilient unsplinted attachment systems for implant-retained mandibular overdentures: two cylindrical attachment systems (Locator R-Tx® and Novaloc®), and one ball attachment system (Ball System). For each attachment system, initial retention is measured as the average of the maximal dislodging forces during 10 insertion-removal cycles. For the Ball System, three activation degrees of the matrix are included versus four and six color-coded retention devices for the Locator R-Tx® and the Novaloc®, respectively, to represent the complete regular retention devices panel. For each retention device or activation degree, eight samples are tested. The initial retention range is similar between the Ball System (7.7 ± 3.4 N - 19.9 ± 4.6 N) and the Novaloc® (2.0 ± 0.5 N - 18.9 ± 1.4 N) and broader for the Locator R-Tx® (3.3 ± 5.0 N - 60.2 ± 6.0 N). In each attachment system, the initial retention of each retention device is significantly different from the others, except for the two most retentive Novaloc® ones. Retention devices were also classified according to their initial retention (low, medium, and maximum). In each retention group, the Novaloc® and the Ball System provided similar retention values lower than the Locator R-Tx®. Most of the retention devices tested provided an initial retention force of over 5 N for all three attachment systems. The Locator R-Tx® had the most comprehensive range, and the Novaloc® seemed to provide the most reproducible values, unlike the Ball System due to the activation required by the operator.

EFFECT OF IMPLANT POSITION ON PROSTHESIS MOVEMENT OFMANDIBULAR TWO IMPLANT-SUPPORTED OVERDENTURE UNDERSIMULATING BITING FORCE - AN INVITRO STUDY

Purpose: Purpose of this study to evaluate the effect of implant position on prosthesis movement of mandibular two implant-supported overdenture under simulating biting force. Materials and methodology: 30 experimental overdentures (N=30) were made for an edentulous mandibular test model, which included artificial mucosa. Based on implant position, 30 samples overdentures were divided into three groups (n=10) (i.e., A and E, B and D,in between B and D). For this study, the ball and O-ring attachment system was used. 100 N vertical loads were used on the left first molar region, 55N on the left canine, and 40N on the mid-anterior area. The loading points vertical displacement as well as the right distal edges horizontal and vertical displacements were measured.A 1-way analysis of variance test was used to statistically analyse the displacement values with the implant position as a factor, (p=.05) was used to statistically analyze the values of the vertical and horizontal displacement at the distal edge of the overdenture. Results:The mean horizontal displacement at right distal edge on incisor, canine and molar loading was highest in Group III with p value < 0.05. when compared in between groups with paired t tests there was no statistically significant difference on incisor loading between group II and Group III with p value >0.05. Mean vertical displacement at right distal edge on incisor loading was highest in group II and on canine and molar loading, it was highest in Group III. Conclusion:Change in implant position influences the displacement of implant supported overdenture.

The effect of ball versus locator attachment system on the performance of implant supported overdenture: A systematic review.

This systematic review was aimed to compare ball and locator attachment system on the basis of clinical and biomechanical performance of implant supported overdenture as well as biological and patient related outcomes. Open and free electronic and manual searches were performed in digital databases including MEDLINE via PubMed, the Cochrane Database of Clinical Trials, and Scopus along with some other reliable sources. From the 667 retrieved records, 11 full-text controlled trials were included in this study. Risk of bias was assessed according to RoB 2.0 except for one RCT (economic evaluation), only assessed by CASP checklist. From the 11 retrieved studies, total 183 locator and 219 ball attachments were identified in 452 subjects of 30yrs-95yrs of age. Studies provided data about prosthodontic complications or maintenance (replacement or the activation of matrix and patrix part, loss of retention, fracture and relining of the prosthesis, fracture of the attachment and the survival probability), oral health impact profile, soft tissue parameters and periodontal complications, marginal bone loss, patient related outcome and cost of the attachment systems. Only 5 studies were assessed at low risk bias, while other 6at moderate to high risk of bias. Locator attachment system show lesser complications including loss of retention and lower maintenance appointments, lesser soft tissue, and periodontal complications than the ball attachment. Ball is better in terms of cost effectiveness. In other related outcomes, no significant differences were noted between ball and locator attachment.

Peri-implant stress distribution assessment of various attachment systems for implant supported overdenture prosthesis by finite element analysis - A systematic review.

BackgroundVarious attachments like ball, bar-clip, magnetic attachments are used in implant supported overdentures. Finite Element Analysis (FEA) a newly innovated technology has been used in dental implantology to evaluate stress distribution patterns. There is little evidence available regarding the stress distribution in peri-implant region for implant supported overdentures. The purpose of the review was to generate scientific evidence on peri-implant stress distribution in FEA model with different types of attachments employed in implant supported overdentures.Materials and methodsSystematic review was conducted as per the Preferred Reporting Items for Systematic Reviews Guidelines and Meta-Analyses statement (PRISMA). A comprehensive search was undertaken by two reviewers from January 2020 to June 2020 with no year limits to published articles. Only in-vitro FEA studies were included. Following electronic databases were searched for published studies- PubMed, Web of Science. Characteristics of the studies tabulated and analysis of articles was done to compare different attachment systems.ResultsLocator attachments showed better stress distribution than ball attachment system in all the studies but one. Two studies showed results in favour of ball attachment compared to bar-clip attachment system when stress was evaluated distal to the implants. No significant difference in terms of stress concentration could be generated between ball versus magnetic/equator versus locator attachment system due to less number of studies and conflicting results.ConclusionVarious studies showed different results due to heterogenicity in selected attachment systems and study designs. Locator attachments showed favourable stress distribution around peri-implant bone than other attachments.

Overdentures the realms of overshadowness or obliviousness

The overdenture is a predictable and valuable option in the treatment of a patient with multiple missing teeth. It aids by preservation of alveolar bone, teeth and supporting structures, maintenance of proprioceptive response and neuromuscular co-ordination, and enhances the quality of a prosthesis by improving the stability, retention and patient acceptance. Often while fabricating an overdenture with retained attachments it becomes mandatory to cast the wax pattern and by no means can that be judged for parallelism with the abutments. A lucid method of obtaining parallelism has been described, adjunct with significant improvement of bite force has been portrayed.Careful case selection and abutment preparation as well as periodic recall is the key to a successful over denture rehabilitation. This case report also depicts the tooth supported overdenture as a viable option with the use of a customized parallelometer which has its ease of use and cost effectiveness for determining parallelism of abutments using a prefabricated ball attachment system and deciphers the increase in bite force in a dynamic manner.

Funding assistance and global productivity in the field of implant overdentures: A bibliometric analysis of 35 years

Statement of problemImplant overdentures have been widely used as a treatment option for edentulous patients. However, the development of implants, aside from commercial growth, requires funding assistance to determine scientific reliability and clinical applications. Nonetheless, bibliometric studies in the implant overdenture field are lacking. PurposeThe purpose of this bibliometric analysis was to evaluate the prevalence of funding and its bibliometric associated parameters according to the financial assistance granted and the implant overdenture documentation over time. Material and methodsSix databases were assessed, and 12 bibliometric parameters related to the economy, geographical origin, publication details, and corresponding author metrics were recorded. An incidence rate ratio was applied by using a multiple Poisson regression model (α=.05) to assess the association between funding and each bibliometric parameter. ResultsIn total, 1369 studies published between 1986 and 2021 were assessed bibliometrically. The prevalence of funded studies was 34.8% (n=477). The parameter associated with the presence of funding was country income (P<.01), with those having a high and upper-middle income being more funded than those with a lower-middle and low income. Oceania and South America were the continents more frequently funded (P<.05), with Africa being the least frequent. Randomized and nonrandomized controlled trials, in vitro studies, and in silico studies were more funded (P<.001) than case reports and series. Stud and ball attachment systems were more funded (P<.01) than studies with more than 1 retention system. Funding increased over time (P<.01), and corresponding authors with a higher h-index had more studies funded (P<.05). ConclusionsThe number of funded studies on implant overdentures increased over the years. Other bibliometric parameters such as country income, continent, study design, retention system, and corresponding author h-index were associated with the frequency of funded studies published.

Effect of Height Differences on the Retention and Wear Behaviour of Ball Attachment System Over Mandibular Dual Implants

Purpose of the study: To comparatively evaluate the effect of height differences on the retention and wear behaviour of ball attachment system over mandibular dual implants. Materials and methods: Two groups of twenty samples each containing polymerised master block of dual implant analogues at same height in Group 1 and dual implant analogues of different heights in Group 2 were fabricated along with ball abutments, nylon cap and metal housing. Qualitative analysis of samples for wear factor were carried out using stereomicroscope and quantitative analysis of retention force at baseline, 360, 720, 1080, 1440 insertion-removal cycles were determined using Universal testing machine. statistical analysis were carried out using independent ‘t’ test and paired sample ‘t’ test.

Mandibular implant-supported overdenture: A systematic review and meta-analysis for optimum selection of attachment system.

Aim:This systematic review aimed to compare different attachment systems used in mandibular implant supported overdentures by assessing outcomes such as prosthodontic maintenance and complication, peri implant tissue changes, retention, and patient satisfaction for optimum selection of attachment system.Settings and Design:This systematic review conducted following Preferred Reporting Items for the Systematic Review and Meta Analysis (PRISMA) guidelines.Materials and Methods:A systematic electronic literature search was conducted through PubMed, The Cochrane Central Register of Controlled Trials (Central), and Science direct. A hand search was also performed for individual journals and reference lists of selected studies. Randomized controlled clinical trials and crossover clinical trials from 2010 to 2020 with follow up of more than 1 year were included. The Cochrane Collaboration's tool was used for assessing the risk of bias of included studies.Statistical Analysis Used:The statistical meta analysis was performed using Review Manager (RevMan) [computer program]. Version 5.4. Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboation, 2020.Results:Six studies that met the inclusion criteria possess the low risk of bias with follow up of more than 1 year were included in this systematic review. Out of four outcomes, meta analysis was performed for prosthodontic maintenance and peri implant tissue changes. Due to the limited availability of data, retention and patient satisfaction were reviewed systematically without meta analysis. The result of meta analysis for ball versus magnet attachment showed statistically significant differences in prosthodontic complications and maintenance, and ball attachment reported fewer complications than the locator attachment (risk ratio [RR] =0.55, confidence interval [CI] =95%, P = 0.03). Peri implant tissue changes were analyzed in the included studies as probing depth and marginal bone loss. The result of meta analysis for probing depth showed no statistically significant difference between bar versus telescopic type of attachment (RR = 0.20, CI = 95%, P = 0.74). The meta analysis results for marginal bone loss showed no statistically significant difference between bar versus telescopic type of attachment (mean difference = 0.35, CI = 95%, P = 0.10).Conclusion:It can be concluded from the current review that bar attachment provided the most superior retention. The telescopic attachment system not only showed the most favorable patient's satisfaction but also reported the least peri implant mucosal changes. The ball attachment system is a favorable choice for limited inter arch space and parallel implant placement.

Radiographic Evaluation of Single Implant Retained Overdenture Using Locator Versus Ball and Socket Attachments

Aim: The aim of this study was to radiographically evaluate ball versus locator attachment systems for mandibular single implant-retained complete over denture. Subjects and Methods: Twenty completely edentulous patients were randomly selected from the Outpatient Clinic, Department of Removable Prosthodontics, Faculty of Dental Medicine, (Boys, Cairo), Al-Azhar University. The patients divided into groups, group I received single implant retained overdenture with ball and socket while group II received single implant retained overdenture with locator attachment. Radiographic evaluation was carried out with periapical radiograph using the extension cone parallel technique. Results: Group I recorded higher bone loss than group after one year of overdenture insertion and the difference was significant. Conclusion: Locator attachment provides optimal results regarding preservation of bone around implant fixture of implant retained overdenture than those with ball and socket attachment.

Locator or Ball Attachment Systems for Mandibular Implant Overdentures: A Systematic Review

The aim of this study is to lecture treatment results award to attachment systems for mandibular implant overdentures in terms of prosthesis retention, marginal bone loss to the implant and patient satisfaction, between locator and ball attachment system. This systematic review was conducted using Wiley and PubMed of match journals regarding inclusion and exclusion criteria. Clinical trial studies on mandibular implant overdentures from January 2009 to November 2019 were chosen 10 articles from 125 articles were lastly included and the data on prosthesis retention, marginal bone loss and patient satisfaction were analyzed similar to attachment systems. From the limited amount of research, the model of attachment did not show a significant difference between marginal bone loss and implant patient satisfaction measure. but, overdentures with locator attachment tend to have a higher retention than the attachments ball. The conclusion is that the locator and the ball attachment system present the same clinical performance on marginal bone loss and patient satisfaction, but the locator attachment has a higher retention than the ball attachment. How to Cite this Article Pubmed Style Muhammad Ikbal, Acing Habibie Mude, Irfan Dammar, Vinsensia Launardo, Ian Afifah Sudarman. or Ball Attachment Systems for Mandibular Implant Overdentures: A Systematic Review. SRP. 2020; 11(9): 15-19. doi:10.31838/srp.2020.9.04 Web Style Muhammad Ikbal, Acing Habibie Mude, Irfan Dammar, Vinsensia Launardo, Ian Afifah Sudarman. or Ball Attachment Systems for Mandibular Implant Overdentures: A Systematic Review. http://www.sysrevpharm.org/?mno=127031 [Access: March 30, 2021]. doi:10.31838/srp.2020.9.04 AMA (American Medical Association) Style Muhammad Ikbal, Acing Habibie Mude, Irfan Dammar, Vinsensia Launardo, Ian Afifah Sudarman. or Ball Attachment Systems for Mandibular Implant Overdentures: A Systematic Review. SRP. 2020; 11(9): 15-19. doi:10.31838/srp.2020.9.04 Vancouver/ICMJE Style Muhammad Ikbal, Acing Habibie Mude, Irfan Dammar, Vinsensia Launardo, Ian Afifah Sudarman. or Ball Attachment Systems for Mandibular Implant Overdentures: A Systematic Review. SRP. (2020), [cited March 30, 2021]; 11(9): 15-19. doi:10.31838/srp.2020.9.04 Harvard Style Muhammad Ikbal, Acing Habibie Mude, Irfan Dammar, Vinsensia Launardo, Ian Afifah Sudarman (2020) or Ball Attachment Systems for Mandibular Implant Overdentures: A Systematic Review. SRP, 11 (9), 15-19. doi:10.31838/srp.2020.9.04 Turabian Style Muhammad Ikbal, Acing Habibie Mude, Irfan Dammar, Vinsensia Launardo, Ian Afifah Sudarman. 2020. or Ball Attachment Systems for Mandibular Implant Overdentures: A Systematic Reviews in Pharmacy, 11 (9), 15-19. doi:10.31838/srp.2020.9.04 Chicago Style Muhammad Ikbal, Acing Habibie Mude, Irfan Dammar, Vinsensia Launardo, Ian Afifah Sudarman. Locator or Ball Attachment Systems for Mandibular Implant Overdentures: A Systematic Review. Systematic Reviews in Pharmacy 11 (2020), 15-19. doi:10.31838/srp.2020.9.04 MLA (The Modern Language Association) Style Muhammad Ikbal, Acing Habibie Mude, Irfan Dammar, Vinsensia Launardo, Ian Afifah Sudarman. Locator or Ball Attachment Systems for Mandibular Implant Overdentures: A Systematic Review. Systematic Reviews in Pharmacy 11.9 (2020), 15-19. Print. doi:10.31838/srp.2020.9.04 APA (American Psychological Association) Style Muhammad Ikbal, Acing Habibie Mude, Irfan Dammar, Vinsensia Launardo, Ian Afifah Sudarman (2020) or Ball Attachment Systems for Mandibular Implant Overdentures: A Systematic Reviews in Pharmacy, 11 (9), 15-19. doi:10.31838/srp.2020.9.04

Retrospective study comparing the clinical outcomes of bar-clip and ball attachment implant-supported overdentures

The aim of this study was to compare the clinical outcomes of implant-supported overdentures (ODs) with either bar-clip or ball attachments. The implant, prosthesis failure, and technical complications were the outcomes analyzed in this retrospective clinical study conducted in a specialty clinic. Seventy-five patients with 242 implants supported by 76 ODs (36 maxillary, 40 mandibular) were included in the study and followed up for 88.8 ± 82.9 months (mean ± standard deviation). Bar-clip and ball attachments were used in 78.9% and 21.1% of the cases, respectively. Forty-three implant failures (17.8%) in 17 prostheses (17/76; 22.4%) were observed in this study. The average period of implant failure was 43.3 ± 41.0 months, and most of them were maxillary turned implants. The bar-clip system demonstrated more complications in the attachment parts compared to the ball attachment system. Poor retention of the prosthesis was similar between the two systems. Loss of implants resulted in the failure of 10 ODs in this study. ODs opposed by natural dentition or fixed prostheses presented with more complications. The Cox proportional hazards model did not show a significant effect on prosthesis failure for any of the factors. These findings indicated that patients with ODs need constant maintenance follow-ups to address the technical complications and perform prosthodontic maintenance regardless of the attachment system used.

Cost-Effectiveness of CM-LOC Attachment versus Ball Attachment Retaining Single Implant Mandibular Overdentures.

AIM:To investigate the cost-effectiveness of the novel CM-LOC attachment compared to the gold standard ball attachment in single implant mandibular overdenture.MATERIAL AND METHODS:Fifty-two completely edentulous patients (50 to 69 years old) seeking to improve the retention of their complete mandibular dentures by installing a single implant in the midline of the mandible were recruited for this study. The patients were equally divided into two groups. The first group received a ball attachment abutment over the implant and the second group received CM-LOC attachment abutment. The initial cost and aftercare (maintenance) cost were calculated for each attachment and compared to each other.RESULTS:The initial cost of the CM-LOC attachment was 2.2 times that of the traditional ball attachment. The after-care cost of the CM-LOC attachment was 2.39 times more than the ball attachment. The total cost of the CM-LOC attachment was 2.22 times that of the ball attachment.CONCLUSION:The ball attachment system showed better cost-effectiveness compared to the CM-LOC attachment from the beginning of the study and throughout all the treatment period during the first year.

Effectiveness of Ball Attachment Systems in Implant Retained- and Supported-Overdentures: A Three- to Five-Year Retrospective Examination.

Purpose: To evaluate implant and prosthetic survival rates, complications, patient satisfaction, and biological outcomes of patients rehabilitated with a ball attachment system for implant retained- and supported-overdentures (IOV), which was in function for 3 to 5 years. Methods: This retrospective study evaluated data collected from patients treated between April 2001 and May 2018 with IOV on splinted and non-splinted implants and a ball attachment system. Patients were followed for 36 to 206 months (mean follow-up was 128.1 ± 51.9 months). Data were collected at the 3- and 5-year follow-up examination. Outcome measures were implant and prosthetic survival rates, technical complications, marginal bone loss (MBL), oral health impact profile (OHIP), and periodontal parameters (bleeding on probing and plaque index). Results: A total of 46 patients (16 males and 30 females) with 124 implants were included in this study. Twenty-five implant-retained overdentures were delivered on 53 unsplinted implants, while the other 21 patients received an implant-supported overdentures and the implants were splinted. At the five-year follow-up examination, one implant and one prosthesis failed in the unsplinted group, resulting in a cumulative survival rate of 97.8% at the patient level. Two minor technical complications were experienced. Conclusions: Implant overdenture retained or supported by ball attachment systems showed high implant and prosthetic survival and success rates. A low number of complications, high patient satisfaction, and successful biological parameters were experienced in the mid-term follow-up. Data need to be confirmed by further randomized trials.

A Comparison of microbial flora in peri-implant sulcular fluid of ball versus locator retained mandibular implant overdentures. A randomized crossover study

Purpose: To evaluate the microbial flora in peri-implant sulcular fluid of edentulous patients rehabilitated with ball and socket and locator retained mandibular 2-implant overdentures.Materials and Methods: 14 edentulous patients were recruited to receive two mandibular implant overdentures and new conventional maxillary complete dentures. Mandibular implant overdentures (MIODs) were retained either by locator or ball attachment systems in random order. After 6 months of function, the attachment systems in the existing dentures were replaced with the other type of attachment. The prevalence of streptococci and staphylococci species (spp.) was analyzedusing blood-agar media at 3, 6 and 9 weeks after pick-up of attachments. The data was then collected, tabulated and statistically analyzed using SPSS. Results: No significant difference was found in bacterial count of either Streptococcus or Staphylococcus spp. between two attachment systems (Ball and socket, Locator) at any of the evaluated time intervals with P-value > 0.05Conclusions: Within the limitations of this study, it can be concluded that there is no difference in microbial flora between the two attachment systems. It can also be suggested that the locator attachments are valid treatment alternative for ball abutments to retain mandibular 2-implant overdentures from a biological point of view.

Evaluation Of Stresses Distribution Pattern In Implant- Retained Maxillary Obturators Using Nova-Lock, Ball &amp; Locator-Bar Attachment Systems. (Three Dimensional Finite Element Analysis)

Purpose: This study was an in in-vitro study conducted to compare the stress distribution pattern in implant retained maxillary obturators with three different attachment systems with the aid of three dimensional finite element analysis.Methods: CT scan was made for a patient with hemi-maxillectomy defect. The CT scan file was exported to a personal computer with Materialize Mimics 10.01 program (Materialize, interactive medical image (Materialize Leuven, Belgium). Mimics were utilized to modify the CT scan of the maxilla to construct 3-D model with Solid Works, Concord, Massachusetts, USA) for finite element stress analysis. All components of the models were constructed thereafter, superimposed till construction of maxillary obturator models. Three implants were inserted in the alveolar bone on the intact side. Ball & Nova-lock locator/ bar attachment systems were simulated according to their structural configurations. A static load of 100 N load was applied vertically & obliquely on the defect side. ANSYS program (Canonsburg, PA, USA) was utilized to solve the problems, The resultant Von Misses stresses in bone surrounding implants were evaluated and compared in the 3 studied models.Results: The highest Von Misses stresses were found in cortical bony layers around the implant adjacent to defect & the least stresses at the area of 3rd implant. Nova-lock retained implant obturtors had recorded the least Von Misses stresses (20. 479 &21.675 Mpa) in comparison to Ball (40.762 & 41.488 Mpa) & locator bar attachment systems (43.526 & 47.203 Mpa) under vertical & oblique load application respectively. All models had shown the highest stresses on oblique load application on the defect side.Conclusions: Within the limitations of this study various conclusions could be drawn: The load direction has more important role than the attachment type in stress distribution pattern in implant retained maxillary obturators.Nova- lock attachment system may induce the least stresses onto implant/ bone interface followed by Ball & locator bar attachment systems.The Locator/ bar attachment may allow better stress distribution in implant retained maxillary obturators than other Bar systems.

Patient satisfaction versus retention of implant overdentures with two attachment systems: A randomized trial

Clinical success with mandibular implant overdentures is highly dependent on a reliable attachment system connecting prosthesis and implants. To compare the levels of retention and patient-based outcomes on implant overdentures retained/supported by cylindrical (LA) and ball (RA) attachment systems overtime and investigate their relationship. Attachment retention (Newtons), and patient satisfaction with the treatment, prosthesis stability, and ability to chew (VAS, 100 mm) were assessed in a crossover trial for both attachment systems at baseline, 1 week, 3, 6, and 12 months and compared to preintervention values. Patients' preference was also recorded. Mean retention of worn attachments and patient satisfaction with denture retention assessed in the preintervention phase were 3.2 N (SD 4.9) and 23.5 mm (IQR 6.5-65.5), respectively. Overall mean retention along the study was higher for RA than LA (difference of 5.0 N, 95%CI: 2.5-7.6; P = 0.0005), declining significantly overtime (P < 0.0001), more steeply for the cylindrical attachment. Differences in VAS ratings between attachments were nonsignificant in the crossover phase (P > 0.05), but general satisfaction, satisfaction with retention, and comfort were significantly higher when compared with preintervention scores (P < 0.05). Ratings of retention decreased significantly overtime for both systems and earlier for LA than RA. Satisfaction was lower when retention was either too low or too high, although there was large variation in this association. At the end of the study, all participants chose to remain with the attachment system that they had received last. Attachment selection should be based on patients' individual characteristics and expectations as satisfaction with the attachment retention and denture stability vary largely among patients.

Evaluation of volumetric wear of abutments on the retention loss of ball attachment systems in implant-retained overdentures: An in vitro study.

There is a lack of studies evaluating the wear of the male components of the ball attachment systems of implant-retained overdentures. The purpose of this study was to compare the volumetric wear patterns four commercially used ball abutments. 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. 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). 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.

Retention of implant-supported overdentures at different implant angulations: comparing Locator and ball attachments.

To assess the effect of implant angulation on the retention of two different attachment systems for implant-supported overdentures after a simulated fatigue period of 5.5years. Two test set-ups were constructed. A two-implant mandibular implant-supported overdenture design was simulated using acrylic resin blocks to support implant replicas (Model 1 and Model 2). The replicas were set up in the canine regions (22-mm inter-implant distance). In Model 1, the implants were parallel (0° to the vertical axis) and in Model 2 they were divergent (20° to the vertical axis). The Locator and the ball attachment systems were tested at both set-ups. A simulated fatigue period of 5.5years that equated to 10,000 cycles of insertion and removal of the denture was used. Retention values for each attachment system at each angulation set-up were measured at baseline, every 500 cycles until 4000 cycles and then every 1000 cycles. After simulated fatigue, the retention for both systems at both set-ups reduced. The Locator system reduced from 108.9 to 20.2N in the parallel set-up and from 82.3 to 17.3N in the divergent set-up. For the ball system, the retention reduced from 56.2 to 46N when parallel and from 45.7 to 40.7N when divergent. Both attachment systems showed a significant reduction in retention after simulated fatigue at both parallel and divergent set-ups. The change in implant angulation caused a significant reduction in retention for the ball attachment system only, although this was still higher at the end of testing than the Locator attachment system. The Locators also had a significantly faster rate of loss of retention at both set-ups. Clinically, this may indicate that the ball attachments may perform better with divergent implants.