Implant-supported Overdentures Research Articles

Retention force and allowable range of the angle of an implant-supported overdenture attachment system using healing screws and a silicone resilient denture liner

Statement of problemChanges in the intraoral condition immediately after implant placement and in patients using fixed prosthetic appliances with implant abutments cause problems that require the use of an easily adjustable implant-supported overdenture system. PurposeThe purpose of this in vitro study was to develop a simulated implant-supported overdenture attachment system by using healing screws for the patrix and a silicone resilient denture liner for the matrix and to investigate the initial retention force, time-course changes, and allowable range of the angle between attachments. Material and methodsTests on the retention force and allowable range of the angle were performed. Attachments using tissue-level healing screws (height: 2.0 and 3.0 mm) for the patrix and a silicone resilient denture liner for the matrix were prepared. In the retention force measurement test, the frequency of insertion and removal was set at 3 per day to simulate a 4-month relief period. The joined attachment model was pulled apart, and the maximum traction (N) required to remove it was defined as the retention force. The retention force was measured every 90 times (representing the number of insertions and removals per month). To test the allowable angle range, 2 patrices were used. The angle between the 2 patrices was set at 0, 10, 20, and 30 degrees, and the angular limit for joining with the matrix was measured. The initial retention force of the healing screw attachments was compared with that of a polymeric O-ring by using 1-way layout ANOVA followed by the Bonferroni test (α=.05). To analyze time-course changes in the 2 types of healing screw attachments, the retention force before insertion and removal was compared with that after repeated insertions and removals for each simulated period using 1-way layout ANOVA followed by the Dunnett test (α=.05). ResultsThe initial retention force of the 2.0- and 3.0-mm healing screws was 2.4 ±0.1 and 2.6 ±0.2 N. After repeating insertions and removals to simulate use for 4 months, the retention force of the 2.0- and 3.0-mm healing screws was 1.8 ±0.2 and 2.2 ±0.1 N, respectively, both showing significant differences from the initial retention force (P<.05). The allowable angle range test revealed that insertion and removal of the healing screws was possible up to 30 degrees. ConclusionsUnder the conditions of this in vitro study, repeated insertion and removal attenuated the retention force but was still equivalent to the retention force of the O-ring. The allowable range of the angle between patrices for insertion and removal was up to 30 degrees.

Evaluation of the clinical efficacy of implant-supported overdenture with edentulous mandible in elderly patients

The aging society of the global population has led to an increase in the number of patients with edentulous jaw, a common multiple disease. Given the developments in implant techniques, the method of implant denture has received a positive and good response in terms of the quality of life and psychological well-being of patients. Implant-supported overdenture in mandible has two main advantages. 1) It has better retention and chewing efficiency than those of mandibular conventional denture. The required implant site of implant-supported overdenture is less than that of fixed implant-supported denture and can repair more defect tissues to help restore beauty and pronunciation. The price of the former is more acceptable than that of the latter. Therefore, this article aimed to systemically analyze and further discuss the clinical effect of implant-supported overdenture in elderly patients; combine existing related studies on the selection of number, site, and upper restoration of implants; and illustrate the advantages of removable implant-supported protheses in the repair of toothless mandible.

Long-Term Survival and Peri-Implant Health of Titanium Implants with Zirconia Abutments: A Systematic Review and Meta-Analysis.

To evaluate the long-term implant survival rate of titanium implants with zirconia abutments, and the effects of implants with zirconia abutments on marginal bone loss (MBL) and pocket probing depth (PPD) compared with all-titanium implants. The searched electronic database included the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, and the Chinese Biomedical Literature Database. Two types of studies were included: clinical studies reporting the survival rate of titanium implants with zirconia abutments with at least a mean/median 5-year follow-up, and clinical trials reporting the effects of implants with zirconia abutments on MBL and PPD compared with all-titanium implants. Two reviewers screened and selected the records, assessed quality, and extracted data of included studies independently. This review included 16 studies from 18 publications. None of the comparative studies was assessed at a low risk of bias. The overall implant survival rate of implants with zirconia abutments was estimated to be 96% (confidence intervals [CIs] [94%, 98%], I2 = 0%). For the comparison between implants with zirconia abutments and all-titanium implants, the results significantly favored implants with zirconia abutments (for MBL, mean difference [MD] = -0.09, CIs [-0.17, 0.00], p = 0.05, I2 = 40%; for PPD, MD = -0.18, CIs [-0.32, -0.05], p = 0.008, I2 = 0%). Zirconia abutments were favored more when the prosthesis was an implant-supported overdenture rather than a single crown. Implants with zirconia abutments may have an acceptable performance on peri-implant health compared with all-titanium implants; however, the implant survival rate of implants with zirconia abutments is slightly lower than all-titanium implants in the long-term follow-up. Additional studies are needed to explain this dichotomy.

What is the Impact of Implant-supported Mandibular Overdentures on Oral Health-Related Quality of Life? A Retrospective Study

Objective: Oral health-related quality of life (QoL) is significantly influenced by the type of the prostheses that is used for prosthetic rehabilitation of patients with complete edentulism. This study aims to retrospectively evaluate the outcomes of mandibular implant-supported overdentures (MODs) through patients’ perceptions by analyzing the results from OHIP-14 index.Methods: Relationships between OHIP-14 scores, and clinical and patient-based findings are investigated.Results: Forty-seven patients were included in the study. OHIP-14 scores ranged from 0 to 35, with a mean score of 5.81 (±6.89), indicating an overall “very high” quality of life. Patients with “very high” QoL had significantly lower pain scores than those with both “high” and “low” QoL (p=0.000, p=0.036 respectively). Further analysis revealed a positive correlation between total OHIP points and pain level (r= 0.738, p=0.000).Conclusion: Within the limitations of this study, it can be concluded that patients with complete edentulism of the mandible can effectively be rehabilitated with two implant-supported mandibular overdentures and be provided with a “very high” oral health-related QoL.

The effect of implant prosthesis complications on patient satisfaction

Statement of problemHow complications regarding implant prostheses affect patient satisfaction and oral health-related quality of life (OHRQoL) is unclear. PurposeThe purpose of this retrospective study was to compare patient satisfaction with implant restorations in patients with or without a history of complications. These data were used to determine whether implant prosthesis complications affected self-reported OHRQoL. Material and methodsData were gathered from 176 edentulous and partially dentate patients who had received implant prostheses consisting of implant-supported crowns, implant-supported overdentures, and screw-retained fixed dental prostheses (FDPs) in predoctoral and postdoctoral clinics between January 1, 2010, and December 31, 2014. Demographics and complications were self-reported by means of a survey. Patients rated their OHRQoL using the Quality of Life with Implant-Prostheses (QoLIP-10) questionnaire. Means were compared by using a 1-way ANOVA to compare the variables of prosthesis complications, sociodemographic data, and patient satisfaction. Significantly different variables were further evaluated using a post hoc Tukey-Kramer Honestly Significant Different (HSD) test (α=.05). ResultsStatistically significant differences in patient satisfaction were found related to prosthesis complications, gender, and marital status. The most common complication for implant-supported crowns was screw loosening. For implant-supported overdentures and screw-retained FDPs, the most common complication was repair of the prosthesis. Those who had experienced complications reported lower OHRQoL scores than those who had not. Women and widows/widowers overall reported lower OHRQoL scores. The OHRQoL scores of women with and without prosthesis complications were not statistically different (P=.073). No significant differences were found relative to age (P=.937) or education (P=.302). Patients without complications with implant-supported crowns reported the lowest satisfaction because of oral hygiene difficulties. The lowest satisfaction in patients with complications of implant-supported overdentures and screw-retained FDPs was related to worry/concern because of problems with the implant prosthesis. ConclusionsThe results of this survey suggest that patients who experience complications with an implant prosthesis report a lower OHRQoL score than those who do not. Future studies are needed to evaluate patient satisfaction by comparing prosthesis complications with and without implants to determine whether patients who have had complications with implant prostheses are more satisfied than those who have experienced complications with conventional prostheses.

Ceria-Stabilized Zirconia/Alumina Nanocomposite for Fabricating the Framework of Removable Dental Prostheses: Preliminary Results from a 4-Year Follow-up.

To clinically evaluate the use of ceria-stabilized zirconia/alumina nanocomposite (Ce-TZP/A) for the frameworks of removable dental prostheses (RDPs). A total of 20 Ce-TZP/A RDPs (10 complete dentures and 10 implant-supported overdentures) were used in 16 patients, and the presence/absence of complications and patient complaints were evaluated. The survival rate of the RDPs during a mean follow-up period of 55.6 months was 100%, with no major complications. The patients experienced uneventful courses functionally and esthetically. In addition, there was no incidence of breakage or repair related to the Ce-TZP/A frameworks.

Rehabilitation of an Extremely Edentulous Atrophic Maxilla with a Pseudoskeletal Class III Relationship

The skeletal class III relationship presents complex dentoalveolar problems, requiring multidisciplinary treatment. In edentulous people, severe atrophy of the jawbone simulates the clinical appearance of a skeletal class III relationship (pseudoskeletal class III), which presents major problems for rehabilitation. This article describes the rehabilitation of a 67-year-old patient with a pseudoskeletal class III relationship. The mandible was restored with two implant-supported bar-retained overdentures using clips for retention. The extremely atrophic maxilla was restored with a combination of sinus augmentation, implant placement, and classic prosthodontic treatment using an electroformed mesostructured overdenture with swivel lock attachments on an implant-supported bar. By performing minimal augmentative and implant surgeries and using the possibilities and advantages of classic prosthetic dentistry, the clinical situation described here could be managed and the atrophic maxilla could be rehabilitated.

A 3D finite element analysis of glass fiber reinforcement designs on the stress of an implant-supported overdenture

Statement of problemEvidence regarding the effect of different glass fiber reinforcement designs on the biomechanical behavior of implant-supported overdentures is lacking. PurposeThe purpose of this finite element analysis was to analyze the stress distribution in an implant-supported overdenture reinforced with a cast metal reinforcement bar and 4 different designs of unidirectional glass fiber to minimize the risk of denture base fracture. Material and methodsA 3D edentulous mandible incorporating an implant-supported overdenture model without reinforcement (control, CT) or reinforced with 1 cast metal bar reinforcement (CM) was placed over the top of the implants and 4 unidirectional glass fiber reinforcements. The glass fiber bundle was placed over the top of the implants (GF), or 2 bundled halves were placed over the top (GO) of, between (GB), or distal (GD) to implants. Three patterns of occlusal loading were simulated: L1, all artificial teeth loaded in the long axis; L2, all left-side teeth loaded in the long axis; and L3, posterior left-side teeth loaded obliquely (45 degrees). ResultsUnder L1 and L3, the tensile stresses were higher for CT, GD, and GO and lower for GF and CM. Under L2, no differences were seen between groups. Stresses were concentrated on the periphery of the O-ring connector, on the basal area, and on the middle-lingual region of the overdenture. ConclusionsReinforcements placed in the middle region and over the top of the implants provided better load distribution. Unidirectional glass fiber behaved as cast metal when used to reinforce the implant-supported overdenture.

Mandibular implant-supported overdentures in (frail) elderly: A prospective study with 20-year follow-up.

PurposeTo prospectively assess long‐term (20 year) clinical, radiographic, and patient‐reported outcomes of an elderly population provided with mandibular implant‐supported overdentures.Materials and MethodsA total of 53 elderly (aged ≥60 years at the time of treatment) were provided with two endosseous implants supporting a mandibular overdenture and a conventional maxillary denture. Outcome parameters—including implant loss, plaque index, gingival index, bleeding index, presence of calculus, probing depth, and satisfaction with implant‐supported overdenture—were scored 1, 5, 10, and 20 years after prosthetic treatment. Radiographic analysis was performed to assess peri‐implant bone changes. At the 20‐year evaluation, frailty (Groningen Frailty Index) and quality of life (EuroQol 5D) were additionally assessed.ResultsA total of 15 patients completed the 20‐year follow‐up. The 20‐year implant survival rate was 92.5%. Plaque index, bleeding index, and probing depth increased slightly over time, while gingival index and presence of calculus remained unchanged. Radiographic analysis revealed minor marginal bone loss during the first 10 years and no further loss thereafter. Participants were very satisfied with their prosthesis and reported a good quality of life. At the 20‐year evaluation, 64.3% of the patients were classified as frail.ConclusionsThe long‐term survival of implants supporting a mandibular overdenture is high. Although most elderly in the study became frail over time, peri‐implant health and marginal bone level remained at a satisfactory level.

Evaluating the influence of different soft liners Retaining mini implant supported mandibular over denture on the marginal bone height

Introduction: Using a soft liner-retained implant-supported overdenture offers the restorative dentist a treatment option when the number, location, or angulation of dental implants placed may differ from the original treatment plan. The aim of the present study was to evaluate the marginal bone height changes in mini-implant supported overdentures using different retaining denture soft-liners.Patients & Methods: Twenty-one completely edentulous cases were selected for this study. The patients were allocated into one of the three treatments groups. In group I the lower overdenture was relined with “acrylic based soft liner”; group II the lower overdenture was relined with “silicon based soft liner’’, while in group III: the lower overdenture was relined with ‘’Retention Sil 200’’. Patients in all groups received CBCT immediately after the implant loading, 6 months and 12months after insertion of partial overdenture. Each implant was evaluated for the marginal bone level. Results: The Silicon, Retention Sil 200 and acrylic based soft liners showed a statistical significant difference in the amount of bone resorption. Conclusion: the current study concluded that Silicon and acrylic based soft liners show significant difference in their effect on the supporting bone due to stresses transmitted to mini-implant retained mandibular over dentures. Retention. Sil resilient liners cannot be considered as a permanent mean of retention for mini implant retained mandibular but it shows high success for short- and medium-term management.

Frequency of Lower Lip Paresthesia in Patients Receiving Implant-Supported Mandibular Dentures in Tabriz, Iran in 2017-2018

Background: Widespread use of dental implants in the past 15 years has resulted in an increase in complications associated with implant surgeries. The aim of the present study was to determine the frequency of lower lip paresthesia in patients receiving implant-supported mandibular overdentures. Methods: In this descriptive, cross-sectional study, 63 patients receiving implant-supported mandibular overdentures were evaluated. For clinical examination, the two-point discrimination test (2DP) was used before surgery and at 1-, 3- and 6-month postoperative intervals. Data was analyzed using descriptive statistical tests and chi-square test. Results: The results showed frequency rates of 19%, 4.8% and 4.8% for lower lip paresthesia at 1-, 3- and 6-month postoperative intervals. At 1-month postoperative interval, female patients exhibited a significantly higher rate of paresthesia compared to male patients (P = 0.035). Conclusions: Lower lip paresthesia was highly prevalent (19%) one-month after implant surgery; however, its frequency decreased over time. After 3 months, the frequency of paresthesia decreased by about 3 quarters (4.8%) and remained constant until 6 months after surgery. During the 1-month period after surgery, female patients had a high rate of paresthesia compared to male patients.

Clinical outcomes of immediately loaded implant-supported overdentures: A long-term prospective clinical trial

Statement of problemLong-term evidence of immediate loading of dental implants with bar overdentures is lacking. PurposeThe purpose of this clinical study was to assess the clinical outcomes of immediate and conventional loading protocols of mandibular overdentures supported by 2 dental implants 14 years after initial placement. Material and methodsTwo groups of edentulous patients who received two TiUnite implants were enrolled in this study. In the experimental group (n=35), the implants were loaded immediately. In the control group (n=16), the conventional delayed loading protocol was followed. Participants of both the groups were treated with overdentures supported by a standardized resilient bar mechanism. Clinical oral health–related quality of life and patient satisfaction outcomes were recorded for 14 years after initial placement of implants and measured at various stages of treatment. ResultsSignificant improvements in all outcomes were observed in both the groups compared with baseline, and this improvement was sustained over the duration of the study. No differences were noted in any of the study outcomes between the 2 groups. ConclusionsBoth the loading approaches provide comparable short- and long-term results. The results of this study confirm that immediate loading of implant-supported overdentures is a predictable treatment approach. Future studies should focus on assessing long-term clinical outcomes with mandibular overdentures in nonsplinted applications.

Implant-supported overdentures with different clinical configurations: Mechanical resistance using a numerical approach

Statement of problemImplant-supported overdentures (IODs) are a treatment option for patients with complete edentulism. However, this treatment increases the possibilities of peri-implant complications, characterized by inflammation or partial loss of surrounding hard and soft tissues. PurposeThe purpose of this finite element analysis study was to evaluate the mechanical performance of different bar-IOD designs under different clinical configurations by comparing the stress and strain distribution on the bone during secondary stabilization. Material and methodsA finite element model of the mandible representing a patient with complete edentulism was developed. Different designs of bar-IODs were modeled and compared. The parameters studied were the material properties (cobalt-chromium, zirconium dioxide, titanium grade 5, and titanium grade 4), diameter and bar-IOD cross-sectional shape, tilt of the posterior implants (30 degrees), presence of a distal extension cantilever in the bar-IODs (12 mm), and number of implants (4 or 6). Two different mastication loading conditions were analyzed. One- and 2-way ANOVAs and the Tukey honestly significant differences post hoc test (α=.05) were used to determine the significant von Mises stress and strain values in the bone. ResultsThe 4 materials tested in the bar-IOD did not have a significant mechanical effect on the bone (P<.05). A smaller diameter and structure of the bar-IOD led to significantly higher bone stress (P<.001). A distal extension cantilever led to an increased stress concentration (model M1 versus model M3: P<.001), which reached 50% in the event of tilting of the posterior implants (model M2 versus model M4: P<.001). Tilting of the posterior implants alone, without extension, had a nonsignificant effect (model M3 versus model M4: P=.999). Model M5 supported with 6 implants reduces the stress transferred to the bone compared with model M3 supported with 4 implants (P<.05). ConclusionsDistal extensions in bar-IODs, the tilt of the posterior implants, and the low amount of material in the cross-sectional area in the bar-IOD were the most influential parameters on the mechanical resistance of dental implants in the mandibular bone.

Effects of attachment type and palatal coverage on oral perception and patient satisfaction in maxillary implant-supported complete denture patients.

The effect of oral rehabilitation on the oral perception of implant-supported overdenture patients is a concern. This study evaluated the effects of the attachment type and palatal coverage on oral perception and patient satisfaction in maxillary implant-supported complete denture patients. The correlation between oral perceptual ability (OPA) and patient satisfaction in three groups was investigated. Group I consisted of dentate individuals (n = 40), Group II consisted of maxillary implant-supported complete denture patients with bar attachments and palatal coverage (n = 12), and Group III of maxillary implant-supported complete denture patients with magnetic attachments and palatal coverage (n = 14). In addition, implant-supported maxillary overdentures with bar attachments, with (Group II; n = 12) and without (Group IV; n = 18) palatal coverage, were examined in terms of patient satisfaction and OPA. The relationship between OPA and patient satisfaction was assessed with the Turkish version of the Oral Health Impact Profile-14 (OHIP-TR-14) satisfaction survey. To compare oral sensory function among the groups, tactile awareness and pressure awareness were assessed. There was no significant difference in OHIP-TR-14 scores between Groups II and III. In addition, there was no correlation between oral tactile function and patient satisfaction in Groups II and III. For patients with maxillary bar-retained implant-supported overdentures, palatal coverage did not affect the correlation between OPA and patient satisfaction, lateral pressure threshold, or tactile thickness threshold. According to the results of the study, whether maxillary implant-supported overdentures were made with a bar- or magnetic-type retainer, and whether bar-retained implant-supported overdentures had an open or closed palate did not affect the correlation between patient satisfaction and oral perception.

Geleneksel ve İmplant Destekli Overdenture Protez Kullanan Tam Dişsiz Hastaların Çiğneme Performansının İn Vivo Olarak Karşılaştırılması

Geleneksel ve İmplant Destekli Overdenture Protez Kullanan Tam Dişsiz Hastaların Çiğneme Performansının İn Vivo Olarak Karşılaştırılması

Comparison of changes in retentive force and wear pattern of two stud attachments for implant overdentures: An in vitro study

Context: Edentulous patients often complain about the instability of mandibular denture. To overcome that, implant-supported overdentures (IODs) have been applied as a good prosthetic option. Aims: The current study compared the changes in retentive force and patterns of surface wear of nylon rings of two stud attachments (ball and locator) upon cyclic loading. Subjects and Methods: Two implant analogs were fixed parallel to each other, 22 mm apart, in custom-made rectangular blocks for each attachment system. Ten nylon inserts of each attachment system were tested. Universal testing machine was used to measure the retentive force, and a low-value fatigue testing machine was used for cyclic loading of 2500 insertion–removal cycles. Surface changes of the components were evaluated by scanning electron microscope (SEM). Statistical Analysis Used: Paired Student's t-test was used to determine groups that were statistically significant. Results: The greatest retention loss rate, i.e., the difference between the initial retentive force and final retentive force was observed in the ball attachment (6.20 N) followed by locator attachment (3.70 N). The results were found to be statistically significant (d ≤ 0.001**). Upon SEM analysis, the nylon inserts of ball attachment revealed more surface wear compared to that of locator attachment. Conclusions: For greater retention and longer function, locator overdenture attachment should be preferred for implant overdentures over ball attachment.

Using concentrated growth factors as an alternative to bone graft material in sinus augmentation to rehabilitate atrophic posterior maxilla

A larger number of senior patients want to eliminate the use of conventional overdenture such as Conventional Complete Denture or Removable Partial Denture and replace it by an Implant-supported fixed prosthesis or at least implant-supported overdenture with the purpose of restoring and improving the masticatory function, aesthetics besides helping them gain confidence to talk and smile. Most of those patients have lost their teeth and been posteriorly edentulous for extended periods of time, causing severe bone resorption and Pneumatized Maxillary Sinus that makes it impossible for conventional dental implant placement. This report reviews two successful cases of rehabilitation of the atrophic posterior maxilla with previous bilateral ridge augmentation in Pneumatized Maxillary Sinuses using solely Concentrated Growth Factors (CGF) without bone graft augmentation with simultaneous implant placement. Where CGF is obtained from the patient's which was collected in blood collection tubes and processed by a special centrifuge device.

A comparative evaluation of immediate versus delayed loading of two implants with mandibular overdenture: An in vivo study.

Introduction:Implant-supported overdenture has been a common treatment for edentulous patients for the past several years and predictably achieves good clinical results, especially in those patients who were uncomfortable with their conventional dentures, as they provide additional retention and support. The concept of immediate loading is more applicable to completely edentulous patients because of their functional and esthetic requirements. Hence, the present study aims to evaluate the outcomes of immediate loading of mandibular two-implant-retained overdenture and compare it with the conventional delayed loading concept.Method:This in vivo study was conducted to compare immediate versus delayed loading of two implants with mandibular overdenture. A total of 20 completely edentulous patients (10 delayed loading and 10 immediate loading) were included in the study and certain parameters, i.e., bone loss around implants, periodontal pocket depth, pain and discomfort, implant stability, and microflora around implants, were measured immediately and after healing period of 3 and 6 months.Result:It can be analyzed from the observations that patients were more satisfied with delayed loading in terms of comfort, speech, function, pain, and chewing efficiency as compared to immediate loading.Conclusion:It is concluded that implants loaded under delayed protocol seem to have a higher success rate as compared to those that are loaded immediately.

Stress and Strain Distribution Patterns in Bone around Tissue- and Bone-Level Implant-Supported Mandibular Overdentures Using Three-Dimensional Finite-Element Analysis.

Our aim is to investigate the effect of implant placement in two positions (bone level and tissue level) on stress and strain distribution around mandibular implant overdentures. We use two models of mandibular overdentures. Taper implants are inserted and collimated between the lateral and canine teeth. All structures are scanned, digitized, and three-dimensioned (3D) model designed. We apply a vertical load of 100 N simultaneously on the central fossa of the mandibular first molar of the two models (bone- and tissue-level implant). Stress and strain values are obtained using 3D finite-element analysis (FEA). In comparison to the tissue-level model, bone-level implants can reduce overdenture movement and tension by 0.8 μm. The results of this study show that using bone-level implants can reduce tension on the prosthesis part of the overdenture and the bone around the implants as well as on the movement of the distal end of the mandibular overdenture. We found that bone strain occurred around implants within physiological limits in model 1 (bone level) compared to model 2 (tissue level). This shows that the distribution of physical forces in bone-level implants generally produces better results than those of issue-level implants. However, more research on the subject is needed.

3D Finite Element Analysis to Assess the Stress Distribution Pattern in Mandibular Implant-supported Overdenture with Different Bar Heights

Proper stress distribution on dental implants is necessary in bar-retained implant overlay dentures. The purpose of the study is to comparatively assess the stress distribution pattern on the crestal bone at the bone-implant interface due to different bar heights using finite element models (FEMs). Eight 3D FEMs were developed from mandibular overdentures with two implants in the canine region separated by a distance of 20 mm. In these models, four different bar heights from the mucosa (0.5, 1, 1.5, and 2 mm) with 12 mm occlusal plane height were analyzed. A unilateral and a bilateral vertical load of 150 N were applied to the central occlusal fossa of the first molar and the stress of bone around the implant was analyzed by finite element analysis (FEA). By increasing the bar height, the maximum stress values around implants on the crestal bone were found to be increased in unilateral and bilateral loading models. In unilateral loading models, the maximum stress was found in a model with a 2 mm bar height (0.46 MPa) on the distal side of the ipsilateral implant, and in bilateral loading cases, the maximum stress was also found in a model with a 2 mm bar height (0.456 MPa). As the vertical cantilever increases (here the bar height), the maximum stress on the crestal bone increases. A minimum of 0.5 mm of space is sufficient between the mucosa and the inferior border of the bar to maintain oral hygiene. From the present study, it can be concluded that an increase in bar height causes an increase in stress levels on the peri-implant crestal bone.