Bar Attachment Research Articles

Effect of different implant positions on strain developed around four implants supporting a maxillary overdenture with milled bar attachment: An in vitro study

Effect of different implant positions on strain developed around four implants supporting a maxillary overdenture with milled bar attachment: An in vitro study

Clinical performance of implant supported mandibular overdentures with cantilever bar and stud attachments: A retrospective study.

Treatment of edentulous patients with implant-supported over-dentures improves denture's retention and stability. Published data concerning implant-supported overdenture with cantilever bars that claimed that can affect the survival and bone loss of implants are scarce. The purpose of this study was to evaluate 5-year clinical performance of mandibular implant-supported over-dentures with different attachment systems. In this retrospective study, 103 patients who had received mandibular over-dentures supported by two implants were evaluated in a 5-year follow up. Studied groups were patients with Spherblock ball attachment (58 patients), Dolder bar with cantilever (36 patients), and Locator attachment (9 patients). Marginal bone-loss around implants, prosthetic complications, soft tissue status of the implants (gingival index, plaque index, pocket depth, and bleeding on probing) were used to compare studied groups. Visual Analogue Scale (VAS) criteria was used to assay patient's satisfaction. One-way ANOVA, Scheffe, Kruskal-Wallis, Mann-Whitney, and Fisher's exact tests, were used for the data analysis (α=0.05). One hundred and three patients (46 male, 57 female, mean age 64.7 ± 8.6) with 206 implants (Strauman) were studied. The implant survival rate was 100% with mean bone loss of 0.22 mm around implants in 5 years. Prosthetic complications including attachment wear and denture fracture occurred more often with ball attachments. The number of attachment replacement, and post insertion appointments were significantly less in patients with bar attachments (p < 0.05). Pocket depth and gingival index were less in the ball attachment (p < 0.05). Mandibular overdenture supported by two implants can be considered a successful treatment in edentulous patients. The frequency of prosthetic complication is higher in unsplinted than splinted superstructures.

Resilient Stud Versus Bar Attachments for Inclined Implants Supporting Mandibular Overdentures. An In Vitro Study of Loading and Dislodging Strains.

To evaluate strain around resilient stud and bar attachments for inclined implants supporting mandibular overdentures during loading and dislodging. A mandibular edentulous model was printed using the laser sintering technique. Two vertical implants and two 30-degree distally inclined implants were placed in canine and premolar areas, respectively. Overdentures were attached to the implants with either a resilient stud (Locator, group 1) or a bar/clip (group 2) attachment. Three strain gauges were mounted at the buccal, lingual, and proximal surfaces of each implant. Microstrains were registered during vertical loading and dislodging force applications and compared between attachments (resilient stud and bar) and implant positions (vertical and inclined). For canine implants, bar overdentures recorded significantly higher microstrains than Locator overdentures during vertical loading. For premolar (inclined) implants, Locator overdentures recorded significantly higher microstrains than bar overdentures during vertical dislodging. For both groups (during loading) and the bar overdenture group (during dislodging), canine (vertical) implants showed significantly higher microstrains than premolar (inclined) implants. Within the limitations of this in vitro study, canine (vertical) implants may be at risk of increased stresses during loading if bar attachments are used for vertical and inclined implants supporting mandibular overdentures, and premolar (inclined) implants may be at risk of increased stresses during dislodging if Locator attachments are used. For both attachments, canine implants showed significantly higher microstrains than premolar implants during loading and dislodging.

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.&#x0D;

Effect of different clip materials of bar attachment on the pocket depth on Tooth- supported overdenture randomized controlled clinical study

Effect of different clip materials of bar attachment on the pocket depth on Tooth- supported overdenture randomized controlled clinical study

Axial and Non-axial Retention Forces of Milled Titanium Bar Versus Locator-Milled Titanium Bar Attachments in Implant-Supported Maxillary Overdenture: An In Vitro Study

Axial and Non-axial Retention Forces of Milled Titanium Bar Versus Locator-Milled Titanium Bar Attachments in Implant-Supported Maxillary Overdenture: An In Vitro Study

Peri-implant tissue health and patient satisfaction of vertical versus inclined posterior implants used to support overdentures with bar attachments. A one-year randomized trial.

This study aimed to evaluate peri-implant tissue health and patient satisfaction of vertical and inclined posterior implants for mandibular bar overdentures. Thirty edentulous participants received four implants in the interforaminal area of the mandible. The patients were randomly assigned into two equal groups; (1) vertical group (control): all implants were inserted vertically parallel to each other. Inclined group (study): the anterior implants were placed vertically, and the posterior implants were tilted 30° distally. Hader bar attachment with two 7 mm-distal cantilevers (vertical group) and without cantilevers (inclined group) was used to connect the implants to mandibular overdentures. Peri-implant tissue health (Plaque [PL] and gingival [GI] indices, pocket depth [PD], and crestal bone loss [CBL]) were evaluated after denture insertion (T0), 6 (T6), and 12 (T12) months after insertion. Patient satisfaction was evaluated using a visual analog scale after 12 months. At T12, the vertical group showed significantly higher PL, PD, and CBL than the inclined group for anterior (p< 0.037) and posterior (p< 0.017) implants. The vertical group showed significantly higher GI than the inclined group for anterior implants (p= 0.003), and the inclined group showed significantly higher GI than the vertical group for posterior implants (p= 0.016). The inclined group showed significantly higher scores for general satisfaction (p= 0.049), prosthesis as a part of you (p= 0.013), appearance (p< 0.001), stability (p= 0.002), ease of cleaning (p< 0.001), and comfort (p= 0.001) than the vertical group. Inclined posterior implants used to support mandibular bar overdentures are recommended than vertical implants, as it was associated with improved patient satisfaction and peri-implant tissue health.

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.

RADIOGRAPHIC EVALUATION OF CRESTAL BONE LOSS FOR BAR RETAINEDIMPLANT OVERDENTURE SUPPORTED BY FOUR IMPLANTS VERSUS ALL ON 4 SCREW RETAINED PROSTHESIS

To compare in-vivo conventional 4 parallelimplant placement and bar attachment with cantilever supporting complete overdenture with All-on four configuration supporting fixed screw-retained denture in the term of crestal bone loss around implants Materials and methods:Twelve male patients with good health and firm mucosa were selected to participate in this study. Each patient received four implants in the canine and second premolar areas of the mandible. The patients were randomly classified according to posterior implants angulation into two equal groups,Group(A) received four parallel implants in the canine and second premolar areas, bar-clip attachment with cantilever retaining complete overdenture while Group(B) recievedTwo anterior parallel implants in the canine region and two posteriorly 30° tilted implants in the second premolar area supporting fixed screw retained prosthesis. Crestal bone loss around implants was measured for each patient by using cone beam computed tomography (CBCT) and evaluation made at T6 and T12 Results:Therewassignificantdifference during comparing Marginal bone loss at 6 months with that of 12 months at mesial, distal, buccal and palatal bone for Group (A)(P=0.01, 0.025, 0.0001 and 0.007 respectively) and Group (B) (P=0.03, 0.028, 0.007 and 0.001 respectively). Comparing the two groups, there was no statistical difference at 6 months or 12 months. Conclusion: Despite the limitations in this study, it can be denoted than both treatment options provide the same values of marginal bone loss Only the patient desire is still the contributing factor for choosing the type of restoration, if the patient desire fixed prosthesis with reduced extensions then treatment option used for group(B) (fixed detachable prosthesis screwed to four implants with the posterior implants tilted 30° posteriorly) however when access for oral hygiene measures is more important with patients that cant maintain hygiene with fixed prosthesis, then the selection of group (A) will be more appropriate.

Effect of Ball and Bar Attachment Type on Patient Satisfaction Using Two-Implant-Retained Mandibular Overdenture: A Crossover Randomized Clinical Trial.

Considering the two-implant-retained overdenture as a first treatment of choice for edentulous mandible, patients using the overdentures need to be satisfied with the type of attachment used. The purpose of this study was to determine level of patient satisfaction with two-implant-retained mandibular overdentures opposing conventional maxillary complete denture using ball-socket and bar-clip attachments. In this within-subject crossover randomized clinical trial, total 20 edentulous patients were given conventional complete dentures for 3months to use. All completed a satisfaction questionnaire before implant placement. They were randomly assigned to receive an overdenture retained by either ball or bar attachment. After 3months satisfaction questionnaires were repeated, and crossover was done by changing the attachments. After use of 3months of alternate attachments, patients were asked to complete the final questionnaires and asked to choose their preferred type. The patient satisfaction scores were recorded after using 3months of conventional complete denture, 3months of first attachment and 3months of second attachment. Data were analyzed using Wilcoxon signed rank test. The P values were adjusted using Bonferroni multiple testing correction, and P < .05 were considered as statistically significant. There was no significant difference in patient satisfaction between ball and bar attachments. However, patient satisfaction improved significantly between baseline and either-attachment-retained prosthesis. At the end of the comparative crossover experiment, 11 patients voted for the ball attachments and 9 for the bar attachments, thereby indicating them as their preferred attachments. Among ball and bar attachment, there was no statistically significant difference in satisfaction scores. Neither ball nor bar attachment was chosen as a preference over the other.

Maintenance requirements and marginal bone loss associated with implant-retained overdentures: a retrospective cohort study.

To evaluate the maintenance requirements and the presence of prosthetic complications associated with marginal bone loss in the implant-retained bar and locator prostheses. The study was executed between the years 2013 and 2018 on 114 patients who had undergone 283 dental implants. Patients were examined at follow-up recall sessions at 12 and 24months after the placement of the dentures. The clinical examination also included intraoral and extraoral examinations of the patients; compatibility of the prostheses placed to about occlusion; an adaptation of the prosthesis to the tissues, health, and continuity of the soft tissues; complaints of the patients; implant success rates; and marginal bone loss, and prosthetic complications were evaluated at follow-up sessions, and statistical analysis was performed. Locator attachment was placed in 94 patients with separated mandibles and maxillae, and a removable prosthesis with a bar attachment was placed in 20 patients. When evaluating the level of marginal bone loss regardless of the presence of complications, the area where the implant was set, the number of days after loading, and the type of retainer, it was found to be significant at the end of the 12th the 24th months. The results showed a significant relationship between the prosthesis type and the presence of complications at month 24 (p < 0.05). There was no significant relationship between the position of the denture and the presence of complications at month 12 (p > 0.05). There was no significant relationship between the location of the denture and the presence of complications at month 24 (p > 0.05). Complications do not affect marginal bone loss, but the resulting marginal bone loss is the result of the patient not paying enough attention to oral hygiene. Routine inspections of the prosthesis after the completion of treatment seem to be important. If the requirements resulting from these checks are met, complications that may occur in the future will be prevented. The maintenance requirements and the presence of prosthetic complications associated with marginal bone loss in the implant-retained bar and locator prostheses were evaluated. Complications occurred more frequently with the bar-supported removable implant prostheses.

Digital fabrication of polyetheretherketone retentive bar attachment inserts as overdenture maintenance: A dental technique

A technique for the virtual designing of retentive attachment inserts for bar-retained 2-implant mandibular overdentures is described. The bar attachment is scanned intraorally, the retentive insert designed with the MESHMIXER software program, and the file 3D printed in resin, which is replicated in polyetheretherketone (PEEK). The technique offers high-quality inserts with good retention that can replace the conventional nylon inserts and reduce the number of maintenance visits and the frequency of changing the bar attachment.

Stress Distribution on Various Implant-Retained Bar Overdentures.

The purpose of this study was to evaluate the effects of various fabrication techniques and materials used in implant-supported mandibular overdentures with a Hader bar attachment over added stress distribution. Three-dimensional geometric solid models, consisting of two implants (3.3 mm × 12 mm) placed at the bone level on both mandibular canine regions and a Hader bar structure, were prepared. Model 1 simulated a bar retentive system made from Titanium Grade 5 material by Computer Numerical Control (CNC) milling technique without using any converting adapter/multi-unit element on the implants, while Model 2 simulated the same configuration, but with converting adapters on the implants. Model 3 simulated a bar retentive system made from Cobalt-Chromium material, made by using conventional casting technique with converting adapters on the implants. Static loads of 100 Newton were applied on test models from horizontal, vertical and oblique directions. ANSYS R15.0 Workbench Software was used to compare Von Mises stress distribution and minimum/maximum principal stress values, and the results were evaluated by using Finite Element Analysis method. As a result, the highest stress distribution values under static loading in three different directions were obtained in Model 1. Stress was observed intensely around the necks of the implants and the surrounding cortical bone areas in all models. In scope of the results obtained, using converting adapters on implants has been considered to decrease transmission of forces onto implants and surrounding bone structures, thus providing a better stress distribution. It has also been observed that the type of material used for bar fabrication has no significant influence on stress values in those models where converting adapters were used.

Prosthetic complications and maintenance of different attachments used to stabilize mandibular 2-implant overdentures in patients with atrophied ridges. A 5-year randomized controlled clinical trial.

This randomized clinical trial aimed to evaluate prosthetic complications and maintenance of different attachments used to stabilize mandibular 2-implant overdentures in patients with atrophied ridges. Ninety edentulous patients with a maladaptive capacity of wearing conventional dentures due to mandibular ridge atrophy received 2-implants in the canine regions using computer-guided surgery. The patients were randomly assigned into three groups; (1) Bar group: overdentures were connected to the implants with bar/clip attachments, (2) Telescopic group: overdentures were connected to the implants using a resilient telescopic attachment, and (3) Stud group: overdentures were connected to the implants with resilient stud (Locator) attachments. Prosthetic complications of attachments, mandibular overdentures, and maxillary dentures, and soft tissue complications of mandibular overdentures and maxillary dentures were evaluated 1 year (T1), 3 years (T3), and 5 years (T5) after denture insertion. The majority of prosthetic and soft tissue complications for all groups occurred in the first year. The most frequent prosthetic complication was wear/distortion of retentive components of locator and telescopic attachments and activation of clips of bar attachment. The bar group showed the highest incidence of overdenture relines, fractures, hyperplasia, maxillary denture mucositis, and soreness. The telescopic group showed the highest incidence of screw loosening, teeth wear/fracture, maxillary denture relines, fractures, teeth wear, teeth separation, and flappy ridges. The stud group recorded the highest incidence of wear and replacement of retentive components. For 2-implant overdentures in patients with atrophied mandibles, bar attachments showed the highest incidence of complications related to mandibular overdentures, telescopic attachments showed the highest incidence of complications related to maxillary dentures, and stud attachments showed the highest incidence of complications related to the attachment components.

Evaluation of the Effects of Attachment Type and Implant Number on Life Quality of Implant-Supported Mandibular Overdenture Prosthesis Patients

Objective: The current study aimed to evaluate the life quality of implant-assisted mandibular overdenture patients who have had additional implant applications and were rehabilitated with ball or bar attachment. Material and Methods: 53 patients who came to Van Yüzüncü Yil University, Faculty of Dentistry, Prosthodontics Clinic for implant-supported mandibular overdenture treatment between 2019 and 2021 were included in this prospective clinical study (32 females, 30 males; mean age: 64.03; age range: 33-90). The patients were called back for the study precisely one year after prosthetic loading of their implants. Implant-supported mandibular overdenture prosthesis patients diverged into six groups: splinted two implants (bar attachment), single two implants (ball attachment), splinted three implants (bar attachment), single three implants (ball attachment), splinted four implants (bar attachment) and single four implants (ball attachment). And they asked for completing the Turkish version of the OHIP-14 questionnaire. Results: Ball attachment was used in 45.28% of the participants, a mandibular overdenture design supported by a bar attachment was preferred in 54.72%. Kruskal-Wallis test results indicated that the number of implants had a statistically significant effect only on functional limitation and psychological disability among the seven OHIP-14 categories evaluated (p=0.018, p=0.009). Accordingly, the average functional limitation score in individuals with four implants was 4.44 ± 1.89. Conclusion: We found that there are a positive correlation between the number of implants and the patient's life quality; however, it can be concluded that attachment type does not significantly affect the scores of the life quality

Prosthetic complications with mandibular bar-retained implant overdentures having distal attachments and metal frameworks: A 2- to 12-year retrospective analysis

Statement of problemLong-term reports on 2-implant-retained overdentures having metal frameworks and bars containing distal attachments are scarce. PurposeThe purpose of this retrospective study was to evaluate prosthetic complications with 2-implant-retained mandibular overdentures with metal frameworks having either screw- or cement-retained cantilevered bars with distal attachments. Material and methodsSeventy-three edentulous study participants who had been treated with mandibular overdentures with 2 implants were included. The parameters assessed were acrylic resin fractures (base fracture, fracture at midline), debonding of teeth, opposing prosthesis fracture, need for relining or rebasing, abutment and bar screw loosening and fracture, ball or bar attachment or clip wear, fracture or detachment, bar fracture, and implant loss. Statistical analysis was performed by using the Mann-Whitney U test as the data were not normally distributed. The categorical variables between the groups were analyzed by using the Fisher exact test (α=.05). ResultsTwenty-seven prostheses had a cement-retained bar, and 46 bars were screw-retained. Of 73 overdentures, 68 were metal-reinforced. The mean observation time was 5.9 years with a range between 2 and 12 years. The most common complication was wear of the Rhein 83 polymer attachment followed by bar screw loosening. The cumulative survival rate for overdentures was 91.9% at 6.8 years. The service life of cement-retained prostheses was significantly longer (P<.05). Bar, resin base, and mid-line fractures were only seen with cement-retained prostheses. The number of times an attachment change was required did not differ between cement- and screw-retained bars. Of 191 implants, 3 were lost, and the cumulative survival rate was 93.5% at 7.5 years. No significant difference was found between retention types in terms of implant loss (P>.05). ConclusionsBased on the participant population observed, the survival rates of 2-implant-retained mandibular overdentures and their implants in the medium term were high. Wear of the polymer attachment was commonly seen. Overdentures with cement-retained bars had bar or acrylic resin fractures. Mandibular 2-implant-retained overdentures with a screw-retained bar containing bilateral distal attachments had fewer prosthetic complications and high implant survival in the medium term.

Mandibular overdenture retained with precision balls and bar attachment

Introduction. Milled precision bar with the lateral additions of two precision attachments could significantly contribute to the primary and secondary retention of partial denture and overdenture. This clinical case demonstrates stability of mandibular overdenture using milled precision bar and two coronally positioned precision attachments. Case report. A sixty-five years old male patient had two preserved canine roots in lower jaw. Semicircular metal-ceramic (PFM) bridge was previously fabricated for upper teeth. Decision for fabrication of milled bar and metal framework of overdenture was established due to the presence of PFM bridge in the upper jaw. The root canals of the two remaining mandibular canines were prepared for posts. After final mandibular impression using A-silicone in a custom tray, master cast with prepared canals of roots of canines was provided. Two posts connected with milled precision bar were designed. Coronal attachments-patrixs were positioned onto the tip of each coronal part of the construction with axial direction of precision attachments towards root canals. The construction was invested and casted. Metal framework of overdenture was designed and casted. After interocclusal record, the artificial anatomic teeth were selected and waxed model of overdenture with matrixes was provided for try-in clinical phase. Finally, the overdenture was flasked and polished. Metal construction of two posts and milled bar were cemented simultaneously with overdenture, using self-adhesive resin cement. Conclusion. Milled bar improves retention and stability of metal framework of overdenture. Coronally positioned patrix of attachment provides redirection of occlusal and other functional forces towards apical root parts.

Comparison of retentive force and wear pattern of Locator® and ADD-TOC attachments combined with CAD-CAM milled bar.

PURPOSEThe purpose of this study was to investigate changes in retention and wear pattern of Locator® and ADD-TOC attachments on a digital milled bar by performing chewing simulation and repeated insertion/removal of prostheses in fully edentulous models.MATERIALS AND METHODSLocator (Locator®; Zest Anchors Inc., Escondido, CA, USA) was selected as the control group and ADD-TOC (ADD-TOC; PNUAdd Co., Ltd., Busan, Republic of Korea) as the experimental group. A CAD-CAM milled bar was mounted on a master model and 3 threaded holes for connecting a bar attachment was formed using a tap. Locator and ADD-TOC attachments were then attached to the milled bar. Simulated mastication and repeated insertion/removal were performed over 400,000 cyclic loadings and 1,080 insertions/removals, respectively. Wear patterns on deformed attachment were investigated by field emission scanning electron microscopy.RESULTSFor the ADD-TOC attachments, chewing simulation and repeated insertion/removal resulted in a mean initial retentive force of 24.43 ± 4.89 N, which were significantly lower than that of the Locator attachment, 34.33 ± 8.25 N (P < .05). Amounts of retention loss relative to baseline for the Locator and ADD-TOC attachments were 21.74 ± 7.07 and 8.98 ± 5.76 N (P < .05).CONCLUSIONCAD-CAM milled bar with the ADD-TOC attachment had a lower initial retentive force than the Locator attachment. However, the ADD-TOC attachment might be suitable for long-term use as it showed less deformation and had a higher retentive force after simulated mastication and insertion/removal repetitions.

General health of patients receiving an implant-retained overdenture. A cross-sectional study

Although ample research has been done on implant-retained overdentures, little is known about the age, health aspects and socio-economic status of patients receiving an implant-retained overdenture for the first time. Therefore, a big data study was set up, in cooperation with Vektis (a Dutch national database for all insured and claimed healthcare), with the aim of investigating the aspects mentioned earlier in patients who received implant-retained overdentures between 2009 and 2016. The study showed that these overdentures were predominantly made for the lower jaw, using a bar attachment system. It also showed they were mainly used for relatively young (55- to 75-year-olds) and healthy patients. It was concluded that relatively few implants are placed to support implant-retained overdentures in patients over 85 years of age and in those with diabetes mellitus, although neither are contraindicated.

Thermocycling Effect on Implant Supported Overdenture Using 3D printed Peek Bar following all-on-4 Concept: Randomized Trial-In vitro Study

Objective: Stress analysis and retention evaluation of implant-retained mandibular complete overdenture with different clip materials and distributions. Methods: This in-vitro study was conducted over implants retained mandibular complete overdenture (all-on-4 concept) using BIOHPP bar attachments constructed using 3 D printing with different clip materials and distributions. This study consisted of 4 groups according to the type and distribution of clips: Group I: hard clips anteriorly and posteriorly, Group II: soft clips anteriorly and posteriorly, Group III: hard clips anteriorly and soft clips posteriorly, and Group IV: soft clips anteriorly and hard clips posteriorly. Stress analysis and retention were evaluated before and thermocycling afterward. Results: Comparison between stresses in each group before and after thermocycling in central and peripheral implants was performed, revealing stresses in all groups after thermocycling were significantly higher than before thermocycling as P < 0.05. Regarding retention, a comparison between all groups revealed a significant difference between them before and after thermocycling as P<0.05. Conclusion: There is no effect of clip material distribution regarding stress analysis and retention before and after thermocycling except stresses in central implant before thermocycling as soft clips anteriorly and hard clips posteriorly revealed significant lower stresses than hard clips anteriorly and soft clips posteriorly.