Implant-supported Mandibular Overdentures Research Articles

Effect of Different Denture base Materials on Stresses Transmitted to supporting structures of Implant-supported Mandibular Overdenture

Effect of Different Denture base Materials on Stresses Transmitted to supporting structures of Implant-supported Mandibular Overdenture

Occlusal equilibration and muscle activity in fixed versus removable mandibular implant supported overdenture

ObjectivesSingle denture rehabilitated patients have negative appraisals regarding oral function, mostly associated by stability and retention issues regarding mandibular prosthetics. Therefore, this study assessed patients’ occlusal equilibration, muscle activity, and oral health-related quality of life (OHRQoL) receiving milled removable or fixed mandibular implant retained prostheses.Materials and methodsTwenty-two edentulous mandibular ridges patients were randomly distributed into two groups based on the definitive prosthesis received. Group I: Removable mandibular implant-supported overdenture, Group II: Implant retained fixed prosthesis. Occlusal equilibration was evaluated utilizing Occlusense, muscle activity via Electromyograph (EMG) at delivery, after one, and three months. The OHRQoL was evaluated by Oral Health Impact Profile questionnaire (OHIP-19) before delivery and after follow-ups. Data were collected, tabulated, and analyzed, utilizing independent t-test and One-way ANOVA followed Tukey`s post-hoc test. Significance level set at P ≤ 0.05.ResultsGroups I &II showed significant improvement in occlusal equilibration, muscle activity and OHRQoL. Group II demonstrated significantly higher improvement than group I in occlusal equilibration associated with muscle activity after 1 month, and in functional limitations domain in OHRQoL questionnaire after 3 months.ConclusionImplant retained mandibular prosthesis showed improvement in occlusal equilibration, muscle activity, and OHRQoL regardless of prosthesis type employed. Fixed implant-supported prosthesis revealed better outcomes than removable mandibular implant-supported overdenture concerning occlusal equilibration, muscle activity, and OHRQoL regarding functional limitations.Clinical relevanceImplant retained mandibular prosthesis is one of best treatment options for single mandibular completely edentulous patients, as dental implants improved occlusal equilibration, muscle activity, and OHRQoL.

Evaluation of Marginal Bone Height Changes in implant-supported mandibular overdenture retained with Two Different Materials of Bar Attachments.

Evaluation of Marginal Bone Height Changes in implant-supported mandibular overdenture retained with Two Different Materials of Bar Attachments.

Effect of Different Denture Materials on Stresses Transmitted to Peri-Implant Areas of Implant-Supported Mandibular Overdenture

Effect of Different Denture Materials on Stresses Transmitted to Peri-Implant Areas of Implant-Supported Mandibular Overdenture

Assessment of peri-implant bone stress distribution with the effect of attachment type and implant location using finite element analysis.

The objective of the current research was to evaluate how stress is distributed in the peri-implant bone of a mandibular overdenture with implants placed asymmetrically to the midline. A 26-year-old male's mandible, with missing teeth, was examined using computed tomography (CT) scanning. Two implants were inserted at right angles to the occlusal plane, in the positions of the right canine and left lateral incisor of the mandible, with an internal connection. Two types of attachments (bar and ball) were designed. To simulate the clinical condition, anterior (on central incisors) and bilateral posterior (on premolars and molars) loadings were applied. The stress distribution was assessed using finite element analysis (FEA). The lateral incisor level implant was found to have the highest maximum principal stress (about 33 MPa) in both models in the anterior loading condition. However, in both models, the canine-level implant revealed more stress values (about 22 MPa) in the posterior loading condition. In mandibular implant-supported overdentures, when implants were placed asymmetrically to the midline, one acted as a fulcrum and sustained more occlusal load. The bar attachment system did not reveal superior results in terms of stress distribution compared to the ball attachment.

Conventional maxillary denture versus maxillary implant-supported overdenture opposing mandibular implant-supported overdenture: Patient's satisfaction.

This study sought to determine the impact of age, gender, and use of maxillary implant-supported overdenture (UISOD) versus conventional denture (CMD) opposing mandibular implant-supported overdenture (LISOD) and the number of years the patient has used their prosthesis on the ratings of satisfaction. This study aimed to assess the long-term influence of different factors on patients'satisfaction with LISODs needing a maxillary prosthesis, helping dentists choose a treatment pathway that leads to a higher satisfaction rate. This cross-sectional study included 84 participants. They were treated with LISOD opposing either CMD or UISOD from 2015 to 2020. They were all eligible to participate in the study. An oral health impact profile (OHIP-14) questionnaire was given to each patient and filled out by them. OHIP-14 scores were gathered and went under statistical analysis with PASS-11 software to determine the relationship between patients'satisfaction with the scores. Age and gender had no significant influence on how satisfied patients were. Patients with maxillary overdentures showed more satisfaction than the CMD group (p < .05). Moreover, patients'satisfaction decreased with increasing years of prostheses usage (p < .05). This study demonstrated that satisfaction is related to the type of maxillary prosthesis (conventional or implant-supported) used opposing LISODs and the number of years the patient had used the prostheses.

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

Objective: The purpose of this in vitro study was to evaluate the retentive behavior of implant-supported overdenture using two different attachment systems (locator and milled bar-clip attachment system).&#x0D; Methods: Six edentulous mandibular models were fabricated from cold‑cure PMMA; the denture-bearing area of the acrylic resin model was covered by an approximately 1.5 mm thick silicone resilient liner to simulate mucosa. The Study models were divided into three groups: Model A (locator), Model B (milled bar-clip attachment system without extension), and Model C (milled bar-clip attachment system with 1cm extension). However, for each study model, a complete mandibular denture was constructed. Anterior, posterior, and central dislodging forces were measured by digital force gauge at the beginning of the study (Initial retention) and after 540 courses of consecutive pulling and inserting the prosthesis (final retention), which was to simulate six months of overdenture use assuming three daily removals and insertions for oral hygiene practice.&#x0D; Results: There were statistically significant differences in retention between the group models, and milled bar-clips attachment systems revealed the highest retentive capacity. However, after six months of simulated use, there was a significant retention loss; retention of Model B recorded the highest percentage loss of 55.1%, while Model A recorded the most minor retention loss of 24%. &#x0D; Conclusions: The bar and clip attachment system offered higher retentive values than the locator attachment system. However, the retention loss was correlated to the particular attachment system, and the bar–clip attachment systems had the highest percent of retention loss. In contrast, the locator attachments were associated with acceptable retention, simplicity, and minimal retention.

Radiographic Comparison of the Crestal Bone Loss in the Bone-Level and Tissue-Level Implants in Implant-Supported Mandibular Overdentures

Introduction: To preserve the peri-implant bone level during implant restorations, multiple variations have been made in the implant-abutment connections and bone level, and tissue level implants have been placed at the bone or tissue levels to restore the function of the lost teeth. This study compared the radiographic amount of crestal bone loss in bone-level and tissue-level implants in the implants supported mandibular overdentures.&#x0D; Methods and materials: This study included 40 patients receiving bone-level and tissue-level implants with mandibular overdentures. A total number of 120 implants were placed by an experienced surgeon in a one-stage surgery. Panoramic images of patients immediately after surgery and at least one year after prosthetic loading were assessed. Bone loss values (distance between implant shoulder to proximal bone) were assessed in the bone-level and tissue-level implants on the radiographs using digital caliper on the surrounding areas of implants, including mesial and distal aspects. The data were subjected to a Student t-test.&#x0D; Results: The mean of Mesial Bone Loss (MBL) of the right canine was reported 0.74 mm. The mean amount of Distal Bone Loss(DBL) of the right canine was 0.78 mm, the mean of DBL of the first incisal was 0.75 mm. The mean of MBL of the first incisal was 0.77 mm, the mean of DBL of the left canine was 0.76 mm. The mean of MBL of the left canine was 0.78 mm. Distal and mesial bone loss in the canine and first incisor bone-level implants were slightly higher than respective tissue-level implants, but no statistically significant differences were noted in this regard.&#x0D; Conclusion: According to the results of this study, both bone-level and tissue-level implants can be successfully used for supporting mandibular overdentures. Since the amount of cervical bone loss was clinically acceptable in both groups (in a period of one to four years with an average of 2.1 years). This study recommends that clinicians choose the type of implant according to clinical need and judgement.

A Three-dimensional Finite Element Analysis to Evaluate the Stress Distribution in Bone with Different Attachment Systems in an Implant-supported Mandibular Overdenture

A Three-dimensional Finite Element Analysis to Evaluate the Stress Distribution in Bone with Different Attachment Systems in an Implant-supported Mandibular Overdenture

An In-vitro Evaluation of Retention Force of All PEEK, All Zirconia and Zirconia-PEEK Telescopic Attachment for Mandibular Overdentures.

The objective of this study is to compare retention capacity of mandibular implant-supported overdenture with all zirconia, zirconia-PEEK, and all PEEK telescopic attachments. Sixty acrylic resin models of mandible were used. Telescopic attachment system was made up of all zirconia, all PEEK, and zirconia-PEEK. Evaluation of retention force was done using universal testing machine. Obtained data were statistically evaluated. Highest initial force value was obtained with zirconia-PEEK group. All PEEK and zirconia-PEEK groups showed significantly decreased final retention values in comparison to their initial values. Zirconia can be regarded as the material of choice for telescopic crown, whereas polyetheretherketone and zirconia-PEEK telescopic crowns showed retention loss over a period of time.

The Effect of Zirconia and Titanium as Abutment Materials on Peri-Implant Soft and Hard Tissues in Mandibular Implant Supported Over-denture

Purpose: To evaluate the effect of zirconia and titanium as abutment materials onperi-implant bone height changes and pocket depth in mandibular implant supportedover-denture. Subjects and methods: Ten completely edentulous patients wereselected from the Outpatient Clinic of the Faculty of Dental Medicine for Girls,Al-Azhar University. Two implants were implanted in the inter-foraminal area ofmandibular ridge. Two different abutments were screwed over implants. Right abutmentwas constructed of zirconia and left one was constructed of titanium. Construction ofmaxillary complete denture and mandibular implant supported over-denture for allpatients was performed. Radiographic and clinical evaluation of implants has beenperformed at denture insertion, 6 months, 9 months and 12 months. Results: Theprevious study illustrated that titanium abutments had significantly higher values ofbone height changes and pocket depth measurements than zirconia abutments duringfollow up period. Conclusion: Zirconia abutments had great superiority over titaniumabutments in preservation of peri-implant hard and soft tissues in mandibularimplant-supported over-denture within the follow up period of this study.

The Effect of Zirconia and Titanium as Abutment Materials on Peri-Implant Soft and Hard Tissues in Mandibular Implant Supported Over-denture

Purpose: To evaluate the effect of zirconia and titanium as abutment materials onperi-implant bone height changes and pocket depth in mandibular implant supportedover-denture. Subjects and methods: Ten completely edentulous patients wereselected from the Outpatient Clinic of the Faculty of Dental Medicine for Girls,Al-Azhar University. Two implants were implanted in the inter-foraminal area ofmandibular ridge. Two different abutments were screwed over implants. Right abutmentwas constructed of zirconia and left one was constructed of titanium. Construction ofmaxillary complete denture and mandibular implant supported over-denture for allpatients was performed. Radiographic and clinical evaluation of implants has beenperformed at denture insertion, 6 months, 9 months and 12 months. Results: Theprevious study illustrated that titanium abutments had significantly higher values ofbone height changes and pocket depth measurements than zirconia abutments duringfollow up period. Conclusion: Zirconia abutments had great superiority over titaniumabutments in preservation of peri-implant hard and soft tissues in mandibularimplant-supported over-denture within the follow up period of this study.

Marginal Bone Level Measurements of Unsplinted Implants Used for Mandibular Overdentures: A Six-Month Randomized Prospective Clinical Study Comparing Early and Delayed Loading Protocols.

Background and purpose Implant-supported mandibular overdentures are a good alternative for patients having poor retention of mandibular conventional dentures. The aim of this prospective study was to evaluate and compare the results between early loading and delayed loading of mandibular overdentures on two unsplinted implants. Materials and methods A total of 14 completely edentulous male patients in the age group of 50-60 years were selected for the study. Two 3.5×13 mm implants were placed in the mandibular interforaminal region. The patients were divided into two groups: (i) the test group in which the overdenture was connected after one week of surgery, and (ii) the control group, in which the overdenture was connected three months after surgery. Marginal bone levels were evaluated at baseline (during loading), three months, and six months post loading. Unpaired 't' test was used for the comparison of intergroup measurements. Results No implants were lost. Marginal bone resorptions showed no statistically significant differences between the two groups over six months period after loading. Conclusion The results of this prospective clinical study suggested that there was no significant difference in the clinical and radiographic state of patients treated with implant-supported mandibular overdentures loaded either one week or three months after implant surgery.

Abutment-Bar Structure Connection Geometry: An Important Design Parameter for Implant-Supported Bar-Retained Overdentures With Cantilever Extension.

When extended distally due to higher loading in the posterior region, implant-supported bar-retained overdentures with cantilever bar extension exhibit greater bending moments on the implants closest to the cantilever bar and increased stresses in the overdenture components. In this study, a new abutment-bar structure connection was introduced to minimize undesired bending moments and reduce the resulting stresses by increasing the rotational mobility of the bar structure on the abutments. Copings of the bar structure were modified to have 2 spherical surfaces, sharing the same center, located at the centroid of the top surface of the coping screw head. The new connection design was applied to a 4 implant-supported mandibular overdenture to create a modified overdenture. Both the classical and modified models had bar structures with cantilever extensions in the first and second molar areas and were analyzed for deformation and stress distribution using finite element analysis, which was also conducted for both the overdenture models without cantilever bar extensions. Real-scale prototypes of both models with cantilever extensions were manufactured, assembled on implants embedded in polyurethane blocks, and subjected to fatigue testing. Both models' implants were subjected to pullout testing. The new connection design increased the rotational mobility of the bar structure, minimized the bending moment effects, and reduced the stress levels in the peri-implant bone and overdenture components, whether cantilevered or not. Our results verify the effects of rotational mobility of the bar structure on the abutments and validate the importance of the abutment-bar connection geometry as a design parameter.

Evaluation of retention of the mandibular implant-supported overdenture with two types of low-profile attachment.

Evaluation of retention of the mandibular implant-supported overdenture with two types of low-profile attachment.

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.

A Two-Year Follow-Up Assessment of Decreasing Crestal Bone Levels Around Dental Implants in Patients Rehabilitated With Mandibular Implant Overdentures.

Aim: This two-year follow-up study was aimed to evaluate declining crestal bone levels around dental implants in patients rehabilitated with mandibular implant-supported overdentures. A three-dimensional advanced radiographic tool, cone beam computed tomography (CBCT), was utilized as radiographic aid in this study.Materials & Methods: A total of 15 patients wearing mandibular implants supported overdentures were studied for two years. Randomization and strict inclusion/exclusion criteria were followed during study execution. Complete dentures were fabricated with standard methods, which were later anchored by a bilateral implant in the mandibular jaw. Bone loss at all four surfaces in all studied implants was estimated by the cone beam computed tomography (CBCT) technique. These assessments were done at postoperative follow-up periods of six, 12, 18, and 24 months. Duly signed and informed consent was obtained from all participating patients.Statistical Analysis and Results: The statistical analysis was completed by the software IBM Corp. Released 2013. IBM SPSS Statistics for Windows, Version 22.0. Armonk, NY: IBM Corp. All relevant data was entered into it to be analyzed with suitable statistical tests. Out of all 15 studied patients, 11 were male, and four were female. P-value was very significant for the age range 35-40 years (0.01). In all instances, the lingual surface showed minimum, while the distal surface showed maximum bone loss when seen at all postoperative phases. Grossly, the mean bone loss ranged between 0.14-0.45. P-value was highly significant for the measurements made at the lingual and distal sides of implants (for both B and D positions). A comparison of both study groups by one-way ANOVA confirmed a highly significant p-value for estimations done between the groups (0.001).Conclusion: Within the limitations of the study, the authors confirmed that crestal bone levels showed a clear decreasing pattern in the postoperative phases. Since these deleterious processes can compromise long-term prosthesis success, operators should consider all these facts while planning to implant an overdenture prosthesis in the lower jaw.

A technique for measuring the clinical retentive forces of mandibular implant-supported overdentures

A novel device for measuring the clinical retentive forces of mandibular implant overdentures is described. The device addresses several drawbacks of the conventionally used methods regarding the application of pure vertical dislodging forces perpendicular to the occlusal plane and the elimination of nonaxial dislodging forces and tipping or rotation of overdentures during the measurements. Moreover, the technique allows for the standardization of the occlusal plane and points of load application.

Long-Term Prosthetic Aftercare of Mandibular Implant-Supported Overdenture

Background: Two of the most popular resilient attachment systems for mandibular implant-supported overdenture (MISOD) are locator and ball attachments. The purpose of the present retrospective cohort study was to assess the long-term prosthetic aftercare and oral hygiene status in edentulous patients rehabilitated with MISOD. Materials and Methods: Forty-five consecutive patients were included (22, group A- ball vs. 23, group B- locator attachments). Attachment incorporation into the MISOD was conducted in a direct (chair-side) intraoral technique at the time of denture insertion. Routine follow-up included yearly visits. The number of visits requiring prosthetic aftercare, either during the follow-up or during the additional visit, was recorded. Outcome parameters included—prosthetic aftercare—the number of aftercare (primary outcome parameter) visits, and dental treatment received (pressure sores relief, liner changes due to loss of retention, loss of retention due to debris accumulation, denture repair—secondary outcome parameters); oral hygiene—gingival index (primary outcome parameter). Results: The mean follow-up of the entire study population was 84 ± 21 months, range 39–120 months. Statistical analysis revealed a lower need for prosthetic aftercare interventions in group A (p &lt; 0.001). The mean number of visits dedicated to pressure sores relief (6.09 ± 1.04 vs. 3.03 ± 0.77, p &lt; 0.001) and liner exchange due to loss of retention (5.6 ± 1.03 vs. 2.09 ± 1.04, p &lt; 0.001), were significantly lower in group A. Debris (food/calculus) accumulation inside the attachment was noted only for the locator’s group (p &lt; 0.001). No statistically significant differences between the groups were noted for denture repair (p = 0.318). Oral hygiene also exhibited statistically significant differences in favor of group A (2.3 ± 0.3 vs. 1.03 ± 0.2, p &lt; 0.001). Conclusions: It can be concluded that using ball attachments for MISOD yields less need for aftercare treatments and improved oral hygiene status over the years.

Impact of Mandibular Implant-supported Overdenture on Changes of Electromyographic Activity, Brain Activity, and Cognitive Function: A Crossover Study

Impact of Mandibular Implant-supported Overdenture on Changes of Electromyographic Activity, Brain Activity, and Cognitive Function: A Crossover Study