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The Journal of Prosthetic Dentistry Feb 2020The performance of a recently introduced overdenture attachment system after cyclic dislodgement is not known.
STATEMENT OF PROBLEM
The performance of a recently introduced overdenture attachment system after cyclic dislodgement is not known.
PURPOSE
The purpose of this in vitro study was to compare a conventional attachment system and a recently introduced attachment system for their dislodgement forces before and after cyclic dislodgement.
MATERIAL AND METHODS
Three acrylic resin models were fabricated with 2 implant analogs (4.1 mm; Zimmer Dental) in different angulations; parallel in the first, divergent by 30 degrees in the second, and divergent by 60 degrees in the third model. Six acrylic resin blocks containing 2 metal housings of 2 different LOCATOR attachments (LOCATOR Legacy [LL], R-Tx, n=3; Zest Dental Solutions) were also fabricated. LOCATOR abutment pairs (LL and R-Tx) were placed onto the analogs. Seven specimens for LL and R-Tx with pink attachments were tested for dislodgement forces, and the values were recorded before and after 1440 times (simulated 1-year use) of cyclic dislodgement using an occlusal loading simulator machine. A 3-way ANOVA was used for dislodgement force comparison before and after cyclic dislodgement for different angulations and for 2 different LOCATOR attachments. Any significant differences were identified with the Tukey HSD test (α=.05). The percentage decrease in the dislodgement force was also calculated.
RESULTS
A significant 3-way interaction was found for the LOCATOR type, implant angle, and time (P<.001). LOCATOR type made a difference for only parallel and 60 degree-divergent implants before cyclic dislodgement (P≤.022). After cyclic dislodgement, a significant effect of the LOCATOR type on dislodgement force was found for only parallel implants (P=.034). In both LOCATOR systems, the dislodgement force was different (P<.001) among different implant angulations, except for parallel to 30-degree comparison, before and after cyclic dislodgement. For both LL and R-Tx, significant differences (P≤.022) were found between before and after cyclic dislodgement for all angulations except LL in parallel (P=.214).
CONCLUSIONS
When implants were parallel, initially, the dislodgement force of R-Tx was higher than that of LL; however, the forces were similar after cyclic dislodgement. When implants were divergent by 30 degrees, there were no differences between the dislodgement forces of the LOCATOR systems before and after cyclic dislodgement. When implants were divergent by 60 degrees, initially, the dislodgement force of LL was higher than that of R-Tx; however, the forces were similar after cyclic dislodgement. Before and after cyclic dislodgement, in each system, dislodgement forces were greater when implants were divergent by 60 degrees than when parallel and 30 degrees. After cyclic dislodgement, dislodgement forces decreased for both systems, except for LL when the implants were parallel.
Topics: Acrylic Resins; Dental Implants; Dental Prosthesis, Implant-Supported; Dental Stress Analysis; Denture Retention; Denture, Overlay
PubMed: 31202554
DOI: 10.1016/j.prosdent.2018.11.009 -
Brazilian Dental Journal Sep 2020This cross-sectional observational study with 24 patients evaluated differences in bite force (BF) and masticatory performance (MP) between conventional complete denture...
This cross-sectional observational study with 24 patients evaluated differences in bite force (BF) and masticatory performance (MP) between conventional complete denture (CCD) and implant mandibular overdenture (IMO) users and the correlation between these variables. The BF test was performed bilaterally with an occlusal force device. During the MP test, patients were asked to chew Optocal particles for 40 cycles. The Shapiro Wilk test was employed to verify the normality of the data, the student t test to identify differences between groups, and Pearson's correlation to investigate interrelationships between variables. A multiple linear regression was subsequently performed via the stepwise method. P values ≤0.05 were considered statistically significant. Unlike IMO users, CCD users presented a significant difference (25.6%) in BF between the dominant and non-dominant chewing side (p=0.04). IMO users presented significantly higher BF (p=0.01) without presenting a dominant side (p=0.38), and also performed significantly better for the following MP parameters: MPX50 values decreased by 27.25% in IMO users (p=0.01), MPB decreased by 48.38% (p=0.01), and ME 5.6 decreased by 53.25% (p=0.02), while ME2.8 increased by 151.57% (p=0.01). The BF and MPX50 in the IMO wearers group were negatively correlated (-0.57; p=0.05); this correlation coefficient was the only parameter included in the multivariate regression model. IMO users have higher BF and better masticatory performance than CCD users, especially in terms of chewed particles size reduction. MP is correlated with a higher BF in IMO users through better particle trituration.
Topics: Bite Force; Cross-Sectional Studies; Denture, Complete; Denture, Overlay; Humans; Mandible
PubMed: 32901716
DOI: 10.1590/0103-6440202003525 -
The Journal of Prosthetic Dentistry Jan 2021Mini implants (<3 mm in diameter) are being used as an alternative to standard implants for implant-retained mandibular overdentures; however, they may exhibit higher...
STATEMENT OF PROBLEM
Mini implants (<3 mm in diameter) are being used as an alternative to standard implants for implant-retained mandibular overdentures; however, they may exhibit higher stresses at the crestal level.
PURPOSE
The purpose of this finite element analysis study was to evaluate the biomechanical behavior (stress distribution pattern) in the mandibular overdenture, mucosa, bone, and implants when retained with 2 standard implants or 2 mini implants under unilateral or bilateral loading conditions.
MATERIAL AND METHODS
A patient with edentulous mandible and his denture was scanned with cone beam computed tomography (CBCT), and a 3D mandibular model was created in the Mimics software program by using the CBCT digital imaging and communications in medicine (DICOM) images. The model was transferred to the 3Matics software program to form a 2-mm-thick mucosal layer and to assemble the denture DICOM file. A 12-mm-long standard implant (Ø3.5 mm) and a mini dental implant (Ø2.5 mm) along with the LOCATOR male attachments (height 4 mm) were designed by using the SOLIDWORKS software program. Two standard or 2 mini implants in the canine region were embedded separately in the 3D assembled model. The base of the mandible was fixed, and vertical compressive loads of 100 N were applied unilaterally and bilaterally in the first molar region. The material properties for acrylic resin (denture), titanium (implants), mucosa (tissue), and bone (mandible) were allocated. Maximum von Mises stress and strain values were obtained and analyzed.
RESULTS
Maximum stresses of 9.78 MPa (bilaterally) and 11.98 MPa (unilaterally) were observed in 2 mini implants as compared with 3.12 MPa (bilaterally) and 3.81 MPa (unilaterally) in 2 standard implants. The stress values in the mandible were observed to be almost double the mini implants as compared with the standard implants. The stresses in the denture were in the range of 3.21 MPa and 3.83 MPa and in the mucosa of 0.68 MPa and 0.7 MPa for 2 implants under unilateral and bilateral loading conditions. The strain values shown similar trends with both implant types under bilateral and unilateral loading.
CONCLUSIONS
Two mini implants generated an average of 68.15% more stress than standard implants. The 2 standard implant-retained overdenture showed less stress concentration in and around implants than mini implant-retained overdentures.
Topics: Dental Implants; Dental Prosthesis, Implant-Supported; Dental Stress Analysis; Denture Retention; Denture, Overlay; Finite Element Analysis; Humans; Mandible; Reference Standards; Stress, Mechanical
PubMed: 33393474
DOI: 10.1016/j.prosdent.2020.09.015 -
The Journal of Prosthetic Dentistry Apr 2021Edentulism has been associated with sensoneurinal hearing reduction, but whether hearing is improved by the provision of an implant-retained overdenture is unclear.
STATEMENT OF PROBLEM
Edentulism has been associated with sensoneurinal hearing reduction, but whether hearing is improved by the provision of an implant-retained overdenture is unclear.
PURPOSE
The purpose of this pilot clinical study was to provide completely edentulous participants with implant-retained complete overdentures and to evaluate the effect on their hearing ability by pure tone audiometry (PTA).
MATERIAL AND METHODS
Fifteen completely edentulous first-time denture wearers were enrolled, and their hearing was evaluated with PTA for air conduction and bone conduction at 6 time intervals: before denture insertion (R1), after denture insertion (R2), 1 month after denture insertion (R3), on the day of suture removal after implant surgery (R4), 3 months later, at the time of loading (R5), and 1 month after implant loading (R6). The Friedman test was performed to find significant differences in the measurements from the completely edentulous state to rehabilitation with a complete denture and an implant-retained complete overdenture. The post hoc Tukey test was used for multiple comparisons (α=.05).
RESULTS
Significant differences were found between R1 and R6, between R2 and R6, between R3 and R6, and between R4 and R6 in PTA in multiple comparisons (P<.05). The post hoc test revealed significant difference in the R1and R6 and R3 and R6 pairs (P<.05) at 500 Hz, 1 kHz, and 8 kHz, whereas only between R1 and R6 (P<.05) at 2 kHz for the air conduction test. In the bone conduction test, a significant difference was observed between the R1 and R6 and the R3 and R6 pairs (P<.05) at 500 Hz and 4 kHz, but only between R3 and R6 (P<.05) at 1 kHz and 2 kHz.
CONCLUSIONS
The study showed that the placement of dental implants improved hearing acuity via the acoustic pathway through air and bone conduction.
Topics: Dental Implants; Dental Prosthesis, Implant-Supported; Denture Retention; Denture, Complete, Lower; Denture, Overlay; Hearing; Humans; Jaw, Edentulous; Mandible; Pilot Projects; Treatment Outcome
PubMed: 32345511
DOI: 10.1016/j.prosdent.2020.02.015 -
The International Journal of Oral &... 2022This study aimed to investigate the effect of attachment type, maximum occlusal force, denture deformation, and other confounding factors on marginal bone loss of... (Clinical Trial)
Clinical Trial
PURPOSE
This study aimed to investigate the effect of attachment type, maximum occlusal force, denture deformation, and other confounding factors on marginal bone loss of two-implant overdentures after 1 year.
MATERIALS AND METHODS
Ninety edentulous patients received two implants in canine areas of the mandible using the computer-guided flapless surgical technique. Three months later, overdentures were connected to the implants with bar, resilient telescopic, and resilient stud attachments. Marginal bone loss was evaluated using standardized digitized periapical radiographs. Maximum occlusal forces were evaluated using a digital bite-force meter. Denture base deformation (denture strains, μm) was evaluated using strain gauges bonded to the polished surface of the denture at the level of the attachments. Regression analysis was adopted to find the relation between marginal bone loss and the following confounders (age, sex, mandibular bone height, period of edentulism, number of previous dentures, attachment type, maximum occlusal force, and denture strains).
RESULTS AND CONCLUSION
Telescopic overdentures showed the highest marginal bone loss and maximum occlusal force, followed by bar overdentures, and stud overdentures demonstrated the lowest values. The highest denture strains were noted with bar overdentures, followed by telescopic overdentures, and stud overdentures showed the lowest strains. Age (P = .022), mandibular bone height (P = .023), number of previous dentures (P = .004), maximum occlusal force (P ≤ .001), and denture strains (P = .048) were significantly correlated with marginal bone loss. For every 1-year increase in age, there was a decrease in bone loss by 0.3%. For every 1-mm increase in bone height, there was an increase in bone loss by 1%. For every one increase in the number of worn dentures, there was a decrease in bone loss by 4.2%. For every 10-N increase in maximum occlusal force, there was an increase in bone loss by 6.4%. For every 10-μm increase in denture strains, there was an increase in bone loss by 0.21%. Sex, time of edentulism, and attachment type did not demonstrate a significant correlation with marginal bone loss.
Topics: Bite Force; Dental Prosthesis, Implant-Supported; Denture, Overlay; Humans
PubMed: 35476869
DOI: 10.11607/jomi.8982 -
Clinical Implant Dentistry and Related... Aug 2022This randomized clinical trial aimed to evaluate prosthetic complications and maintenance of different attachments used to stabilize mandibular 2-implant overdentures in... (Randomized Controlled Trial)
Randomized Controlled Trial
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.
PURPOSE
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.
METHODS
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.
RESULTS
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.
CONCLUSION
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.
Topics: Atrophy; Dental Implants; Dental Prosthesis, Implant-Supported; Denture Retention; Denture, Overlay; Humans; Mandible
PubMed: 35466498
DOI: 10.1111/cid.13093 -
The International Journal of... 2020This investigation has been stimulated by the Osseointegration Foundation, working in conjunction with the Zest Anchors implant company. There are three basic valuable...
This investigation has been stimulated by the Osseointegration Foundation, working in conjunction with the Zest Anchors implant company. There are three basic valuable activities that emerge from a professional foundation, which were reflected in this case study. They include disseminating information to practitioners, to persuade young clinicians to become research investigators, and to reach out to patients in need of treatment who cannot afford it without a charitable opportunity.
Topics: Charities; Dental Implants; Dental Prosthesis, Implant-Supported; Denture, Overlay; Humans; Osseointegration
PubMed: 32032413
DOI: 10.11607/prd.4531 -
International Journal of Implant... Dec 2022To assess the implant and prosthesis survival rates, the clinical, radiographical and patient-related outcome measures, and the masticatory performance of maxillary...
PURPOSE
To assess the implant and prosthesis survival rates, the clinical, radiographical and patient-related outcome measures, and the masticatory performance of maxillary overdentures supported by two implants in patients with an atrophic maxilla.
METHODS
In this case series, 15 consecutive patients who were eligible for maxillary implant overdenture therapy, but who had insufficient bone volume to place at least four implants and were unwilling to be treated with reconstructive surgery were asked to participate. After giving consent, participants received two implants in the maxilla under local anaesthesia. After 3 months of osseointegration, a maxillary overdenture with palatal coverage and solitary attachments was fabricated. Implant and overdenture survival, marginal bone level change, clinical outcome measures, masticatory performance and patient-related outcomes were evaluated at baseline and 1 year after overdenture placement.
RESULTS
Fourteen out of 15 participants completed the follow-up period of 12 months. Implant and overdenture survival rate were 89.3% and 85.7%, respectively. Change in marginal bone level (- 0.5 ± 0.7 mm), change in probing depth (0.0 ± 1.0 mm), and clinical outcomes were favourable. Masticatory performance and patient-related outcomes improved significantly compared to baseline. Complications were minimal.
CONCLUSIONS
Within the limitations of this study, it can be concluded that patients with extreme resorption of the maxilla that are unwilling to be treated with reconstructive surgery, benefit from two-implant maxillary overdentures retained by solitary attachments in terms of improved masticatory functioning and denture satisfaction. However, they have relatively high risk of implant loss.
TRIAL REGISTRATION
UMCG Trial Register (RR201900060), registered 22 January 2019.
Topics: Humans; Jaw, Edentulous; Denture Retention; Dental Prosthesis, Implant-Supported; Dental Implants; Denture, Overlay; Atrophy
PubMed: 36484878
DOI: 10.1186/s40729-022-00460-0 -
Gerodontology Mar 2021To systematically review and evaluate the effects of different types of attachments, implant numbers and loading protocols on the peri-implant mucosa of... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
To systematically review and evaluate the effects of different types of attachments, implant numbers and loading protocols on the peri-implant mucosa of implant-supported overdentures (ISODs).
BACKGROUND
The impact of peri-implant tissue health on the ISOD treatment outcome is unclear, and current evidence is inadequate on this aspect.
MATERIALS AND METHODS
A systematic literature search for randomised controlled trials or prospective studies was conducted in indexed databases from 1995 to April 2020. The focused question was as follows: How does the peri-implant mucosa respond to implant-supported or implant-tissue-supported complete overdentures based on different types of attachments, implant numbers, and loading protocols, in terms of clinical outcomes achieved [plaque index (PI), gingival index (GI), probing pocket depth (PD) and bleeding index (BI)]? A random- or fixed-effects model was applied to measure the significance of standardised mean differences (SMD) of PD between the groups.
RESULTS
Seventeen studies met the eligibility criteria. The SMD for PD between splinted/bar and unsplinted/stud attachments was 0.10 mm (95% CI: -0.27 to 0.47; P = .60) and between 2- and 4-implant groups was 0.15 mm (95% CI: -0.16 to 0.45; P = .34), which were not statistically significant. Significant difference (P = .003) was observed between immediate/early loading and delayed loading (SMD = 0.46 mm [95% CI: 0.16 to 0.75]).
CONCLUSIONS
Probing depth for the immediate loaded implants was significantly higher than for the delayed loading group. No attachment type, implant number or loading protocol seemed to have a clear advantage over the other, in terms of other peri-implant mucosal outcome measures.
Topics: Dental Implants; Dental Prosthesis, Implant-Supported; Denture, Overlay; Humans; Mandible; Mucous Membrane; Prospective Studies; Treatment Outcome
PubMed: 33164257
DOI: 10.1111/ger.12505 -
Clinical and Experimental Dental... Apr 2021The World Health Organization (WHO) recognizes edentulism as a physical impairment that results in a negative impact in the daily activities. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The World Health Organization (WHO) recognizes edentulism as a physical impairment that results in a negative impact in the daily activities.
OBJECTIVE
The study aimed to compare the satisfaction and the quality of life, in patients treated with implant retained overdentures with two mandibular implants (IOD) against those with mandibular conventional complete dentures (CCD).
METHODS
Different search strategies were used to screen for articles in Pubmed/Medline, Cochrane Library and Scielo of the last 17 years (2003-2020). The keywords used were: "quality of life OR satisfaction" AND "complete denture OR conventional denture" AND "overdenture OR implant retained."
RESULTS
Six articles and two more were added by manual search. The population was 400 in the CCD and 412 for IOD. The mean age was 64.3 ± 6.41 years. The group was comprised of 283 men and 427 women. The scores obtained in the visual analog scale (VAS) before and after the treatment were statistically significant in favor of the IOD for overall satisfaction, (WMD: 12.329; 95% CI: 4.873 to 19.784, p-value = 0.001), comfort, speech and stability. For esthetics and chewing there was non-significant improvement while hygiene worsened for the IOD. For the comparison after the treatment between both treatment modalities a statistically significant improvement was found in overall satisfaction (WMD: 14.408; 95% CI: 8.589 to 20.226, p-value < 0.001), comfort, speech, chewing and stability in favor of the IOD but not in esthetics or hygiene.
CONCLUSIONS
This systematic review and meta-analysis show the superiority of the IOD, despite is not achieved in all aspects.
Topics: Aged; Dental Implants; Dental Prosthesis, Implant-Supported; Denture, Complete; Denture, Complete, Lower; Denture, Overlay; Female; Humans; Male; Middle Aged; Patient Satisfaction; Personal Satisfaction; Quality of Life
PubMed: 33205918
DOI: 10.1002/cre2.347