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

A 28-Year-Old Woman with Down Syndrome, Congenital Heart Disease, and a History of Knee Surgery and Plantar Fasciitis, with Hallux Abducto Valgus (Bunion) and Lapiplasty Three-Dimensional Correction Surgery

BACKGROUND Tarsometatarsal joint (TMJ) arthrodesis is common method used for correcting hallux abductus valgus (HAV). Its popularity has grown due to studies revealing HAV's triplanar deformity with frontal plane rotation. This case report presents a 28-year-old woman with Down syndrome, congenital heart disease, and a history of knee surgery and plantar fasciitis, with severe HAV deformity and flexible valgus flatfoot associated with ligamentous hyperlaxity. CASE REPORT Examination revealed severe foot deformities, and radiographic studies confirmed the condition. A surgical intervention was planned, and the patient's cardiologist confirmed she was fit for the procedure. The modified Lapidus technique with frontal plane rotational correction included realigning the metatarsal joint, resecting spurs, osteosynthesis material, and arthrosis in the sinus tarsi. After surgery, the patient underwent a recovery period without support for 8 weeks and received appropriate medical care. Radiographs showed successful alignment, and the patient gradually resumed her daily activities. The patient had an uneventful recovery, and postoperative radiographs showed good alignment in all planes. CONCLUSIONS The hyperlaxity associated with Down syndrome makes the incidence of HAV more frequent, and TMJ fusion is preferable to correction by osteotomy. The modified Lapidus technique with frontal plane rotational correction could be a good technique to achieve satisfactory correction in patients with severe HAV deformity and flexible valgus flatfoot associated with ligamentous hyperlaxity. TMJ fusion is indicated when severe or recurrent rotational component is observed in X-rays.

Retention of Different Attachment Systems for Digitally Designed Mandibular Implant Overdenture

PURPOSE

Primary retention and gradual loss of retention of different attachment systems are important key factors in proper attachment selection; however, studies on attachment retention show a wide range of retention values concerning the same attachment system. This in vitro study uses a novel approach that utilizes a digitally designed and 3D-printed reinforced overdenture, which has a digitally determined geometric center, in order to standardize results for future research and clinical work. This study aims to evaluate initial retention along with the gradual loss of retention at different time intervals between three types of stud attachments, retaining a digitally designed, reinforced mandibular overdenture after 5475 cycles simulating 5 years of attachment usage.

MATERIALS AND METHODS

An epoxy model of an ACP Class I (American College of Prosthodontists) edentulous mandible was constructed. A fully computer-designed surgical guide was employed after virtual denture design to place two implants according to prosthetically driven implant placement protocol. A metal meshwork with tissue stops was designed digitally to reinforce the denture and to carry the geometric center. The meshwork was incorporated into the denture-intaglio surface, which was planned for attachment pickup. Forty-eight digitally designed and metal-reinforced 3D-printed dentures were divided into four groups (12 dentures for each group). Loss of retention was measured to compare two novel Locator attachments (12 pairs of Locator R-TX, 12 pairs of Locator F-TX medium and low retention, with 12 pairs of ball and socket). Each group was subjected to an insertion and removal fatigue test resembling 5 years of patient usage. Retention values were recorded using a universal testing machine.

RESULTS

Locator F-TX medium and low retention showed loss of retention by 91.93% and 92.91%, after fatigue testing equivalent to 2 and 3 years of use, respectively. Ball and socket and Locator R-TX showed loss of retention by 19.87% and 26.31%, respectively, after fatigue testing equivalent to 5 years of use.

CONCLUSIONS

Locator R-TX attachment systems showed promising retention for implant overdentures compared to ball and socket attachments. The proposed digital technique of denture reinforcement is capable of standardizing results for research and clinical work.

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

Objective

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.

Material and methods

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.

Results

From the 11 retrieved studies, total 183 locator and 219 ball attachments were identified in 452 subjects of 30 yrs–95 yrs 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 6 at moderate to high risk of bias.

Conclusion

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.

Effect of Various Retentive Element Materials on Retention of Mandibular Implant-Retained Overdentures

This study aimed to examine the retentive characteristics of each retentive element material and the effects from thermocycling using the two implant-retained mandibular overdenture model. Two stud abutments and three retentive element materials; nylon, polyetheretherketone (PEEK) and polyvinylsiloxane (PVS) were used in this study. Four tested groups, with a total of 40 overdentures, were fabricated, including a Locator® abutment with nylon retention insert (NY), Novaloc® abutment with PEEK retention insert (PK), Locator® abutment with PVS retention insert (RL), and Novaloc® abutment with PVS retention insert (RN). The retentive force (N) was measured before thermocycling, and at 2500, 5000, and 10,000 cycles after thermocycling. Significant changes in the percentage of retention loss were found in the NY and PK groups (p < 0.05) at 6 and 12 months for the RL group (p < 0.05) after artificial aging. The RN group exhibited a constant retentive force (p > 0.05). The tendency of the percentage of retention loss significantly increased for PEEK, nylon, and PVS silicone over time. The results of the present study implied that retentive element materials tend to lose their retentive capability as a result of thermal undulation and water dispersion. Nylon and PEEK, comprising strong polar groups in polymer chains, showed a higher rate of retention loss than polyvinylsiloxane.

Assessment of role of complete dentures in improving the chewing efficiency of edentulous patients

Introduction:

The loss of teeth leads to difficulty in chewing and smiling and an unesthetic appearance. The present study assessed the role of complete dentures in improving the chewing efficiency of edentulous patients.

Materials and Methods:

Eighty-two complete denture wearers of age group 40–75 years of both genders were enrolled in the study. The chewing efficiency of denture was determined by VMM machine. Patients were provided with the self- administered questionnaire and were advised to answer.

Results:

Out of 82 patients, there were 42 (51.2%) males and 40 (48.8%) females. The mean ± SD particle size was found to be 0.12 ± 0.07 mm in males and 0.13 ± 0.06 mm in females. A non-significant difference was observed (P > 0.05). The mean ± SD satisfaction level value was 1.28 ± 0.07.

Conclusion:

There was improved chewing efficiency with the complete denture, and the patient satisfaction level was high among patients.

Comparison of retention of two different attachment systems used in implant-supported overdentures

Aim:

This study aims to compare the retentive capacity of two attachment systems after manual thermocycling.

Settings and Design:

In vitro study and Comparative trail.

Materials and Methods:

An edentulous mandibular Polymethyl Methacrylate model was fabricated to receive the overdentures with the two attachment systems to be compared. Two dental implants were placed in the predetermined right and left mandibular canine regions of the model. A total number of eight overdentures, four per group, were fabricated over the two implants with two attachment systems to be compared; Bar and clip attachment system (Group-1) and Locator attachment system (Group-2). All the overdentures were subjected to 5000 alternating thermal cycles using manual thermocycling. Then the samples were subjected to 100 vertical pulls each in the anterior and posterior regions using a universal testing machine and the mean retentive forces were calculated for each sample in the anterior and posterior regions, respectively.

Results:

The mean retentive forces after 100 vertical pulls, were calculated and tabulated for each sample in the anterior and posterior regions separately. Then, the cumulative mean of the anterior and the posterior regions were calculated for each group. The cumulative mean retentive forces of both the attachment groups were-Group-1 (Bar and clip attachment system) = 27.87 N ± 4.01 and Group-2 (locator attachment system) = 18.85 N ± 2.50 with a P value of 0.021. This difference was found to be statistically significant.

Conclusion:

Within the limitations of the present in vitro study, the bar and clip attachment system offered better retention than the locator attachment system.

Retention force of Molloplast-B with ball attachment in implant-supported overdentures: An in vitro study

Aim

The purpose of this study is to evaluate the retention effectiveness of Molloplast B as a female attachment compared to O rings' in implant supported overdentures.

Settings and Design

This systematic review and meta-analysis was evaluated using the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines.

Materials and Methods

Sixteen female part models were divided into two groups: eight female parts made with O ring (Group A) and eight female parts made with Molloplast B (Group B). All of the models were soaked in artificial saliva for 24 h, then, their retention force was measured in Newton using a Universal mechanical testing machine, initially, after 500, after 1000, and after 1500 of loading and dislodging cycles.

Statistical Analysis Used

: The statistical analysis was conducted by using one way ANOVA test and Bonferroni test. SPSS Software (SPSS, Version 27, IBM Co., Chicago, IL, USA).

Results

After 1500 loading and dislodging cycles, Group B has the highest mean retention force (4.09), followed by Group A, which has a mean retention force of 3.73.

Conclusion

Molloplast B with a 2.7 mm diameter ball attachment lost the least amount of retention force after 1500 loading and dislodging cycles.

In vitro assessment of polyetheretherketone for an attachment component for an implant-retained overdenture

STATEMENT OF PROBLEM

Frequent maintenance because of the limited lifetime of overdenture attachments with O-rings has led to the development of materials that might improve their functionality and longevity. However, testing of newly developed attachment materials is lacking.

PURPOSE

The purpose of this in vitro study was to evaluate a newly developed attachment made of polyetheretherketone (PEEK) for an implant-retained overdenture.

MATERIAL AND METHODS

Specimens of PEEK, polyacetal, and Teflon O-ring materials were prepared for analysis of roughness, surface hardness, and compressive strength. For the fatigue resistance test, new specimens based on acrylic resin were subjected to 2880 insertion and removal cycles. Compression and roughness data were compared with the Kruskal-Wallis and Dunn post hoc test; hardness data with ANOVA and t test; and fatigue and stereomicroscopy with ANOVA with repeated measures, t test, and Bonferroni adjustment (α=.05).

RESULTS

Polyacetal had the lowest surface roughness (P=.038). There was a significant difference in hardness among the materials (P<.05). PEEK presented the highest compressive strength among the materials (P<.001). For the fatigue resistance, only polyacetal showed a difference between the initial time-point (P<.05) and subsequent time-points. Polyacetal had a higher fatigue resistance than Teflon (P<.001) and PEEK (P<.05). Regarding the internal deformation of the attachments, a significant difference was observed among the materials (P<.05).

CONCLUSIONS

PEEK showed promising results regarding the physicomechanical properties necessary for use as an overdenture attachment when compared with other evaluated materials. In addition, the PEEK attachment showed results comparable to those in the control group (O-rings) in terms of retention.

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.

Comparative evaluation of biting force and chewing efficiency of all-on-four treatment concept with other treatment modalities in completely edentulous individuals

Aim:

To compare and evaluate biting force and chewing efficiency of all-on-four treatment concept, implant-supported overdenture, and conventional complete denture.

Settings and Design:

Invivo – comparative study.

Materials and Methods:

A total of 12 edentulous patients were included in the study and conventional complete dentures were fabricated. Patients were divided into two groups. In Group 1, complete dentures were replaced with implant-supported overdenture, and in Group 2, complete dentures were replaced with hybrid denture supported by all-on-four treatment concept. The biting force was assessed using a bite force sensor and electromyographic recordings were made by electromyogram for masticatory muscles when chewing three different consistencies of foods.

Statistical Analysis Used:

The data was statistically analyzed using software SPSS version 22.0. Paired t-test was used for intra-group comparison and unpaired t-test was used for intergroup comparison.

Results:

The difference in biting force and chewing efficiency for all-on-four treatment concept was statistically significant for overdenture and complete denture. The highest biting force and chewing efficiency were observed for all-on-four treatment concept, followed by implant-supported overdenture and complete denture.

Conclusion:

The study concluded that the completely edentulous individuals with atrophic posterior alveolar ridges can be rehabilitated successfully with improved biting force and chewing efficiency by All-on-four treatment concept.

A systematic review and meta-analysis of the attachments used in implant-supported overdentures

AIM

To evaluate the survival rate, tissue response, and patient satisfaction of different attachments used in implant overdenture.

SETTINGS AND DESIGN

Systematic Review and Meta-analysis.

MATERIALS AND METHODS

Electronic search of peer-review articles published between 2001 and 2019 assessing the attachments used for implant-supported overdentures was done according to PRISMA Guidelies. The review evaluated sixteen articles related to survival of the attachments, the reaction of the soft and hard tissues along with repair and maintenance of the attachments, and overall performance of the overdenture attachments.

STATISTICAL ANALYSIS USED

There is statistically significant heterogeneity (Q =374.7403, df = 15, and P < 0.0001). The statistics of fixed-effect model reported an MD of - 0.0880 (95% CI = -0.1536; 0.0225).

RESULT

The review evaluated the 16 articles that met with the inclusion and search criteria. The studies were the combination of bar and ball attachments and their subtypes, magnetic and bar attachments, and locator in combination with other attachments. The meta-analysis of combined 16 studies reported acceptable heterogeneity among 16 studies (I 2 = 96%) and reported to be statistically significant (P < 0.01).

CONCLUSION

The survival rate of attachments was in the range of 95.8%-97.5% for bar, 96.2%-100% for ball, 90%-92% for magnet and locator attachments were in the range of 97% after a mean follow-up period of 3 years. The bar attachments reported moderate tissue reaction in the form of mucosal changes, gingival inflammation, and bone resorption. The locator attachments require higher maintenance and repair. The magnetic attachments produce higher bone resorption and readily displace under functional force. Patient satisfaction and compliance was higher for ball, locator, and bar attachments as well as low for magnetic attachment. Thus, the ball and locator attachments excellently perform in terms of survival rate, tissue response, and patient satisfaction.

In Vitro Effects of Cyclic Dislodgement on Retentive Properties of Various Titanium-Based Dental Implant Overdentures Attachment System

The purpose of this study was to evaluate the change in the retentive forces of four different titanium-based implant attachment systems during the simulation of insert–removal cycles in an artificial oral environment. Five types of titanium-based dental implant attachment systems (Locator, Kerator, O-ring, EZ-Lock, and Magnetic) were studied (n = 10). The specimens underwent insert–removal cycles in artificial saliva, and the retentive force was measured following 0, 750, 1500, and 2250 cycles. Significant retention loss was observed in all attachment systems, except the magnetic attachments, upon completion of 2250 insertion and removal cycles, compared to the initial retentive force (p < 0.05). A comparison of the initial retentive forces revealed the highest value for Locator, followed by the Kerator, O-ring, EZ-Lock, and Magnetic attachments. Furthermore, Kerator demonstrated the highest retentive loss, followed by Locator, O-ring, EZ-Lock, and Magnetic attachments after 2250 cycles (p < 0.05). In addition, the Locator and Kerator systems revealed significant decrease in retentive forces at all measurement points (p < 0.05). The retention force according to the insert–removal cycles were significantly different according to the types of dental implant attachment systems.

A low-profile universal attachment system with housing welded to metal reinforcement framework to retain mandibular implant overdenture: A clinical report

Literature has proved that implant-retained overdenture is one of the best prosthetic options in the rehabilitation of complete edentulism. Tissue-supported implant-retained overdentures have been an appropriate treatment modality for atrophic mandibular ridges. In this case report, the patient presented with Class I maxillomandibular relationship and Class II Prosthodontic Diagnostic Index. The patient was concerned about esthetics as well as the retention of the lower denture. Taking into consideration the above concerns, an implant-retained mandibular overdenture was the chosen treatment modality. There are numerous attachment systems that have been used to improve the retention, stability, and support of implant-retained overdenture. Every attachment system has its own set of advantages. The OT Equator is a new line of low-profile attachment which is a radically modified OT-CAP Normo. The rationale for using this attachment is that it is considered the smallest attachment system available with the least overall dimension. It is a resilient and self-aligning attachment system which can be used in limited inter-arch space situation. OT equator derives its name from the OT Dental Laboratory (Bologna, Italy) used as a brand name. Considering these advantages, this was the chosen attachment and proved beneficial in terms of both patient satisfaction and the overall success of the treatment.

Evolution of in vivo assessed retention forces in one-piece mini dental implant-retained mandibular overdentures: 5-Year follow-up of a prospective clinical trial

BACKGROUND

The evolution of retention forces in one-piece mini dental implants (MDIs) retaining implant overdentures (IODs) is of major importance, as the male parts cannot be exchanged, due to the implant design.

PURPOSE

To report the evolution of retention forces of one-piece MDIs, retaining mandibular IODs with ball/ O-ring attachments during 5 years assessed in vivo.

MATERIALS AND METHODS

Four MDIs were installed in the interforaminal region and immediately loaded using the existing mandibular complete denture. Directly post-op, at the 1-year and the 5-year follow-up, the retention forces were assessed with a validated strain gauge at each implant site separately.

RESULTS

At the male part, changes could only be observed at implant site 34: During the first year, there was a statistically significant increase, whereas the retention forces were decreased at the 5-year follow-up. At the female part, retention forces decreased significantly over time. Baseline values could be reestablished by exchanging the O-rings. The changes of the retention forces were more obvious in the posterior, compared to the anterior implants.

CONCLUSIONS

Retention forces at the female part decrease significantly over time, when retaining mandibular IODs by MDIs with ball/ O-ring attachments. Baseline values can be reestablished by exchanging the O-rings. At the male part, changes of retention forces depend on the implant location.

Does the retention system influence the stability of implant-supported maxillary overdentures? A comparison with fixed and conventional dentures

PURPOSE

The purpose of this in vitro study was to compare the stability of removable implant-supported maxillary overdentures with fixed complete dentures and conventional dentures.

METHODS

Four types of complete dentures were tested: conventional complete dentures; overdentures retained by a male resilient attachment system; overdentures retained by a combination of clip bar and attachment system; and fixed complete dentures. Each group was placed in the posterior and anterior region and the stability was recorded by measuring the vertical displacement of the prosthesis.

RESULTS

There was a difference in the vertical movement of the prosthesis according to the type of system. The results showed that the behavior of the overdenture retained by a combination of a clip bar and attachment system is comparable with the stabilization of an implant-retained fixed complete denture.

CONCLUSIONS

Overdentures retained by a combination of a clip bar and attachment presented better stability and retention capacity under our experimental conditions, close to that of the positive control (fixed complete denture), with the advantages of removable overdentures.

Locator® versus ceramic/electroplated double-crown attachments: a prospective study on the intraindividual comparison of implant-supported mandibular prostheses

OBJECTIVES

Implant-supported overdentures are an established dental treatment mode. The aim of this prospective study was and interindividual comparison of patient satisfaction with restorations retained by a prefabricated and thus inexpensive attachment system (Locator®) or with a technologically complex and thus expensive attachment system (ceramic/electroplated double crowns) with similar retentive performance.

MATERIALS AND METHODS

Twelve patients received a Locator and a double-crown prosthesis in a crossover study for test periods of 3 months each. The main target parameter was the patient's final decision in favor of one of the two prosthesis types.

RESULTS

After completing both test phases, seven patients opted for the Locator prosthesis and five patients opted for the double-crown prosthesis.

CONCLUSION

Given the predominant lack of statistically significant differences, the two types of prostheses can be described as equivalent. A recommendation in favor of the Locator prosthesis can be motivated by its lower cost.

CLINICAL RELEVANCE

The results of the study show that the more cost-effective variant was comparable to the more expensive double-crown prosthesis under the conditions prevailing in the study. Depending on the indication, this may influence the decision-making process in daily clinical practice and support the clinician's patient information and consultation efforts.

A comparative evaluation of fatigue resistance of two different implant overdenture stud attachments with two different denture base materials: An in vitro study

Introduction:

The two implant-supported overdentures have overcome the retention and stability-related problems of conventional mandibular denture. Stud attachments are widely available, less expensive, and easy to use.

Aims and Objectives:

To determine fatigue resistance of two different stud attachments with two denture base materials – autopolymerizing and heat cure acrylic resin till 4320 cycles simulating 03 years of service.

Materials and Methods:

Stud implant overdenture attachments, i.e., ball and socket and Dalla Bona attachments were tightened over the implants in two different mandibular edentulous base models. The housings were incorporated with both direct (chairside) and indirect (laboratory) technique into conventional mandibular dentures. These overdentures were subjected to continuous removal and insertion on Universal Testing Machine till 4320 cycles simulating 3 years of service assuming that patient takes out denture, 4 times in a day. The fatigue resistance was calculated for 0, 1440 (1 year), 2800 (2 years), and 4320 (3 years) cycles. Unpaired and paired t-tests were applied to find the level of significance.

Results:

Ball and socket attachments housed with heat cure acrylic resin (indirect technique) had the highest values of fatigue resistance at all cycles. Following were Dalla Bona attachments with autopolymerizing acrylic resin (direct technique), ball and socket attachments with autopolymerizing acrylic resin (direct technique), and Dalla Bona attachments with heat cure acrylic resin (indirect technique) as per statistical analysis.

Conclusion:

Two implant-supported mandibular overdenture with ball and socket attachments incorporated by indirect technique showed higher values in terms of retention and absence of disengagement/fracture of components.

Effect of bar cross-section and female housing material on retention of mandibular implant bar overdentures: A comparative in vitro study

Aim:

The aim of this study is to evaluate the effect of different cross-sections of bar connecting two implants on the retention of mandibular overdentures with Hader clip or lined with heat-cured resilient liner as a housing material. The retentive values after simulated 1.5 years of service were also recorded.

Materials and Methods:

Edentulous mandibular acrylic model was constructed with two dummy implants located in the canine region and connected with cast bar assembly. According to bar cross-section and anchoring method, four groups (n = 10) of identical overdentures were used as Hader bar/clip group (HCG), Hader bar/silicone liner female housing group (HSG), oval bar/silicone liner female housing group (OSG), and round bar/silicone liner female housing group (RSG). Each overdenture sample was subjected to simulated wear up to 2740 manual insertions/separations. The mean retentive forces were measured at the baseline and after every 500 insertions. The data were statistically analyzed using one-way analysis of variance.

Results:

The present study demonstrated that all bar cross-sections showed a significant difference at the baseline (P < 0.05), but HSG showed greater initial retention compared to HCG, OSG, and RSG. OSG showed a significant higher retention after 2740 insertions (simulated five insertions/day).

Conclusions:

Within the limitation of this in vitro study and for a similar period of service, heat-cured silicone female housing for Hader bar could maintain greater retention for two-implant-retained overdentures than provided by conventional plastic clip after 1.5 year. The oval bar recorded reasonable initial retention values and maintained these values for 1.5 years of service.

A comparative evaluation of chewing efficiency, masticatory bite force, and patient satisfaction between conventional denture and implant-supported mandibular overdenture: An in vivo study

Purpose:

The purpose of this within-subject crossover clinical trial was to compare and evaluate the chewing efficiency, masticatory bite force, and patient satisfaction with conventional dentures and two implant-retained mandible overdentures after 4 weeks of usage.

Method:

This within-subject crossover clinical trial was carried out in the Department of Prosthodontics in K.D Dental College and Hospital. A total 15 patients were selected for the study. To report the changes in chewing efficiency by chewing 6gms of peanuts with 40 chewing strokes and comparing the particle size of the chewed material between two implant retained mandibular overdenture with that of conventional denture using micro vu excel gantry type visual measurement machine. To report changes in masticatory bite force after transition of conventional complete denture patient to implant retained overdenture after using the prosthesis for four weeks each and recorded by digital transducer. To assess the patient satisfaction after transition of conventional complete denture patient to implant retained mandibular overdenture with help of OHIP edent patient satisfaction questionnaire.

Results:

The chewing efficiency for implant retained overdenture increased significantly than that of conventional denture. The particle size decreased to 76.34% for implant supported overdenture than that of conventional denture. The chewing strokes required by conventional denture was 69 strokes and that by implant supported overdenture which was 40 strokes to get the same mean particle size. The patients satisfaction after receiving the implant retained overdenture was significantly higher than that of complete denture.

Conclusion:

The provision of two mandibular implants significantly improves measures of oral function and better quality of life for edentulous patients.