Maxillary and mandibular overdentures retained by two unsplinted narrow-diameter titanium-zirconium implants - A clinical pilot study.

OBJECTIVES: To evaluate the survival rates and marginal bone loss of narrow-diameter titanium-zirconium implants supporting complete maxillary and mandibular overdentures up to 3 years after loading. MATERIALS AND METHODS: Ten completely edentulous patients who were dissatisfied with their complete dentures were enrolled. Two narrow-diameter implants were placed in the canine region of the maxilla and mandible. After second-stage surgery, implant-supported overdentures (palatal-free) attached by parallel alignable stud-attachments were placed. Patients were followed periodically for up to 36 months. Standardized radiographs were taken at baseline, 12 and 36 months to analyze mean marginal bone level changes around the implants. RESULTS: The Kaplan-Meier survival rates were 100% for mandibular and 68.0% (SE ± 10.9%) for maxillary implants at 36 months (p = .008). Six maxillary implants failed after loading; no mandibular implants were lost. Five implants failed due to loss of osseointegration. One implant fractured. The mean marginal bone level changes around the analyzed implants (n = 28, 9 patients) were -0.71 ± 0.82 mm in the mandible and -2.08 ± 1.52 mm in the maxilla at the 36-month follow-up. The difference in marginal bone level changes between the maxilla and mandible was significant (p = .019) at the 12- and 36-month follow-ups. CONCLUSION: Two narrow-diameter titanium-zirconium implants with stud-attachments showed a highly satisfactory outcome in the mandible. The maxillary implants showed a high failure rate and significantly more bone loss over time than the mandibular implants. The minimal concept of two implants and an overdenture should be limited to the edentulous mandible.

Comparison of Implant-Retained Overdenture and Conventional Complete Denture: A Survey Study to Measure Patients' Satisfaction and Quality of Life in Dental School Clinics.

Patient satisfaction and quality of life are integral to assessing oral health care quality. For many Americans still using conventional complete dentures (CDs) or implant-retained mandibular overdentures (IODs), it remains essential to consider improving their oral health outcomes and quality of life. Due to inexperienced student dentists providing dental care to dental school patients, patient grievances are generally considered a problem. Patient feedback and satisfaction have proven valuable resources for monitoring and improving patient safety. While CDs and IODs are the 2 leading treatment options for edentulism, more comparative studies in the literature need to compare their outcomes in a school setting. The research question that guided this comparative analysis was, "Is patient satisfaction and quality of life affected by the type of prostheses and provider?" A validated questionnaire was mailed to 520 individuals selected from records of patients who had received treatment for edentulous mandible at a student prosthodontic clinic at the University of Kentucky College of Dentistry from 2014 to 2016 with at least 1 year of follow-up time. A validated questionnaire for edentulous patients based on the Oral Health Impact Profile (OHIP-19) was used. In addition, information on patients' oral health-related quality of life, including questions related to the edentulous patients' satisfaction with their dentures, was collected. The response rate was 33% (N = 171). The study's findings confirm previous findings, suggesting that IODs may significantly impact oral health-related quality of life. Data show that 76% of the IOD group reported improvement in experience when using the implants to retain the mandibular denture. However, there were no statistically significant differences in the OHIP scores between overall CD and IOD patient groups. Males with IODs had lower physical pain, limitations, and disability scores than males with CD. However, females with IODs reported more significant concerns associated with a social disability and handicap domains. Comparing users who had experiences with both treatment options, this study discerned essential characteristics that contribute to increased patient satisfaction with IODs and identified significance in outcomes by gender. These findings guide prosthodontic practitioners' patient care practices and identify a continuing need to discuss CD and IOD treatment protocols within dental school curricula.

Evaluation of masticatory performance and patient satisfaction for conventional and 3D-printed implant overdentures: a randomized crossover study.

BACKGROUND: This crossover clinical study aimed to evaluate and compare masticatory performance and patient satisfaction for patients rehabilitated with conventional heat-cured acrylic resin and 3D-printed mandibular implant overdentures retained with bar attachment. MATERIALS AND METHODS: Sixteen completely edentulous healthy participants received new conventional dentures. In the mandible, four interforaminal implants were inserted. Following the stage of osseointegration, the bar was constructed in a trapezoidal configuration. Each patient randomly received the following overdentures using a crossover design: (1) conventional heat-cured acrylic resin overdenture and (2) 3D-printed overdenture (developed by scanning of mandibular conventional overdenture). The masticatory performance was assessed by conducting a two-colour mixing ability test at 5, 10, 20, 30, and 50 masticatory cycles. Moreover, the McGill Denture Satisfaction Questionnaire (MDSQ) was employed to assess patient satisfaction. Evaluation was performed after 3 months of using each overdenture. Paired sample t tests were used to compare the masticatory performance and MDSQ scores of patients for both prostheses. RESULTS: No significant difference in masticatory performance was reported between the two types of overdentures. Regarding patient satisfaction, only the esthetic aspect was significantly better for conventionally processed overdentures than for printed overdentures. Insignificant differences were observed regarding other MDSQ items between the two overdentures. CONCLUSION: Within this clinical study, 3D-printed implant overdentures showed promising results in terms of chewing efficiency and patient satisfaction compared to conventionally fabricated implant overdentures. TRIAL REGISTRATION: Retrospectively registered at www. CLINICALTRIALS: gov : NCT06148727.(28/11/2023).

Four-year assessment of masticatory function in mandibular overdenture wearers: A randomised clinical trial comparing two to four implants to retain the prosthesis.

BACKGROUND: Limited data exist on the mid- to long-term masticatory capacity of mandibular overdenture (IOD) wearers, particularly regarding the use of posterior implants to retention. OBJECTIVES: To periodically evaluate mastication of IOD wearers, comparing the effectiveness of two to four implants to retain the prosthesis. METHODS: In a randomised controlled clinical trial, 20 complete edentulous patients (14 women), aged 51-84 years (mean age 69.1 ± 9.6), received new bimaxillary complete dentures (CD). After adaptation, baseline measurements of masticatory performance (X50) and swallowing threshold were conducted using the sieving method. Patients were then randomly assigned to groups: control (two intra-foraminal regular implants) and experimental (two intra-foraminal regular implants and two extra-short posterior implants) (n = 10 each). After 4 months, implants were splinted, and a new mandibular IOD was fabricated with bar/clip retention. Mastication was reassessed after 6, 12, and 48 months, and data analysed with repeated measures ANOVA and Sidak's post hoc (α = 0.05). RESULTS: Despite a loss of two patients per group, masticatory performance significantly improved after mandibular IOD installation (p = .031) in both groups (p = .670). A second improvement was observed after 6 months (p = .027), with no subsequent changes (p > .05). Swallowing threshold improvements were noted with IOD, and no discernible differences between groups were observed (p > .05). CONCLUSION: Masticatory function significantly improved after mandibular IOD installation, with the number of implants demonstrating minimal influence. CLINICAL TRIAL REGISTRATION: The present study was not registered in a public database, as mandated. It is important to note that the recommendation for registration was initiated in 2017 by the Committee of Medical Journal Editors, while patient inclusion in the research took place in 2016. Given that the data presented in this manuscript cover a follow-up period of up to 4 years post-surgical intervention, delayed registration was not feasible.

Mandibular overdenture with a single implant in the canine region (c-SIMO): a feasibility study.

OBJECTIVES: The aim of this multi-center pilot study was to assess the viability and feasibility of a novel treatment concept - the canine-positioned single implant mandibular overdenture (c-SIMO), with the single implant placed on the patient's preferred chewing side instead of the midline. MATERIALS AND METHODS: Participants received a single implant in the canine region of their preferred chewing side, based on an Asymmetry Index observed during mastication. The pre-existing mandibular denture was transformed into a c-SIMO on a spherical attachment. The primary outcome was oral health-related quality of life (OHRQoL), measured with GOHAI and OHIP-EDENT. Secondary outcomes included denture satisfaction index (DSI), chewing efficiency (CE), maximum bite force (MBF), implant survival and success, and prosthetic maintenance. Data analysis included descriptive statistics and bivariate comparison tests. RESULTS: Fifteen participants received the c-SIMO treatment (mean age: 69.9 ± 7.0). Implant success and survival rates were 100% at 1 year. Patient-reported outcome measures improved significantly compared to pre-treatment values (OHIP-EDENT: p = 0.001; DSI: p = 0.001; GOHAI: p = 0.002). Masticatory outcomes also improved significantly (CE: p = 0.001; overall MBF: p = 0.005). Post-implant, MBF was significantly higher in the ipsilateral side compared to the contralateral side at 2 weeks (p = 0.019) and 3 months (p = 0.015), but no longer at T3 (p = 0.730). Common prosthodontic events included denture base adjustments (n = 17) and matrix activation (n = 9). CONCLUSIONS: This pilot study concludes that c-SIMO is a promising treatment option, and a potential alternative to the single midline implant overdenture. CLINICAL RELEVANCE: The novel treatment concept of a canine-positioned single implant mandibular overdenture could be a viable treatment alternative to the midline positioning.

Retention of Mandibular Complete Overdentures using Mini Dental Implants (Ø < 3 mm) and Standard Diameter Implants (Ø > 3mm): A Systematic Review and Meta-Analysis of Randomised Controlled Trials.

PURPOSE: The objective of the present systematic review and meta-analysis was to assess randomised controlled trials (RCTs) which assessed the efficacy of mini dental implants (MDIs) and standard-diameter implants (SDIs) in retaining mandibular overdentures (MO). MATERIALS AND METHODS: The focused question was "Is there a difference in the mechanical stability between MDIs and SDIs in retaining MO?" Indexed databases were searched up to and including November 2023 using different keywords. Boolean operators were used during the search. The literature was searched in accordance with the PRISMA guidelines. The PICO characteristics were: patients (P) = individuals with complete mandibular dentures requiring dental implants; Intervention (I) = placement of MDIs under mandibular dentures; Control (C) = placement of SDIs under mandibular dentures; Outcome (O) = comparison of stability between MDIs and SDIs in supporting mandibular dentures. Only RCTs were included. Risk of bias (RoB) was assessed using the Cochrane RoB tool. RESULTS: Five RCTs were included. The numbers of participants ranged between 45 and 120 edentulous individuals wearing complete mandibular dentures. The mean age of patients ranged between 59.5 ± 8.5 and 68.3 ± 8.5 years. The number of MDIs and SDIs ranged between 22 and 152 and 10 and 80 implants, respectively. The follow-up duration ranged between one week and 12 months. Three RCTs reported an improvement in the quality of life (QoL) of all patients after stabilisation of mandibular dentures using MDIs or SDIs. In one RCT, peri-implant soft tissue profiles were comparable between MDIs and SDIs at the 1-year follow-up. The implant survival rate was reported in two RCTs, which were from 89% to 98% and 99% to 100% for MDIs and SDIs, respectively. All RCTs had a low RoB. CONCLUSION: Mini dental implants represent a viable alternative to traditional standard-diameter implants when seeking optimal retention for mandibular overdentures.

An Innovative Technique for Assessment of Bone Change, Bite Force, and Retention of the Single-Implant-Supported Mandibular Overdenture: A Clinical Study.

This study is the first study to incorporate a novel approach to single-implant-retained mandibular overdenture with a bar attachment on a single implant in the symphysis region. The use of a single-implant-retained bar overdenture significantly improved patients' chewing efficiency, indicating enhanced overdenture retention and stability. Materials and Methods: Ten maxillary and mandibular completely edentulous patients were enrolled in the study. A complete denture was fabricated for them. On completion, bite force, retention force, and bone change were recorded. Bite force was recorded with the strain gauge, retention force with the force measurement gauge, and bone changes with radiographs. Conclusion: Single-implant-supported bar mandibular overdenture (SISBOD) can be a suitable standard economic option for edentulous mandible and can greatly improve the quality of life of patients.

Comparison of Man Hours Utilized for Mandibluar Overdenture Treatment Retained by Single Implant with Bar Fabricated by CAD-CAM Process and Conventional Casting Processs - An Vivo Study.

Introduction: Both the population's average life expectancy and the number of patients without teeth are rising. A 2012 epidemiological survey in India found that 30% of the population is edentulous. The rehabilitation process with a set of removable maxillary and mandibular complete dentures is the standard treatment for patients who are edentulous. This study is the first to incorporate and compare a novel approach to a single implant-retained mandibular overdenture with a bar attachment fabricated by CAD-CAM and a casting process on a single implant in the symphysis region. Method: Five maxillary and mandibular completely edentulous patients were enrolled in the study. Results: Significant difference was seen in the conventional laboratory time and CAD-CAM time as P < 0.05. Conclusion: Compared to the conventional casting process, the single implant-supported bar mandibular overdenture (SISBOD) with a novel bar required fewer man hours and was more convenient.

One-Piece Mini Dental Implant-Retained Mandibular Overdentures: 10-Year Clinical and Radiological Outcomes of a Non-Comparative Longitudinal Observational Study.

This study presents the first 10-year follow-up investigation of the implant survival and peri-implant outcomes of one-piece mini dental implants (MDIs) retaining mandibular implant overdentures (IODs), including marginal bone level alterations (ΔMBLs), clinical peri-implant parameters, and complications. Twenty participants with horizontally atrophied mandibles received complete dentures and four MDIs (diameter 1.8 mm) at baseline. The dentures were converted into IODs with O-ring attachments. The 10-year follow-up comprised a radiological assessment of ΔMBLs, peri-implant parameters, as well as biological and technical complications. Results from a 10-year follow-up of 14 participants showed a 100% implant survival rate for all 56 implants. The mean ΔMBL after 10 years was -1.12 ± 0.80 mm, with 49 implants classified as successful (ΔMBL < 2 mm) and 7 implants with satisfactory survival (ΔMBL 2-4 mm). Time after implant placement significantly influenced ΔMBL, with stable MBLs after 5 years. The prosthetic survival rate after 10 years was 93%. ΔMBLs were not influenced by implant position or gender but were significantly smaller in subjects older than 65 years. Conclusively, one-piece MDIs with O-ring attachments offer a reliable treatment option for horizontally atrophied mandibles after 10 years, with high implant and prosthetic survival rates, potentially benefiting from advanced age regarding peri-implant bone stability.

Implant-supported, bar-retained maxillary overdenture and Mandibular Implant-supported, metal- acrylic resin, screw-retained, fixed complete denture on an edentulous patient: Case Report.

Most edentulous patients prefer fixed restoration or detachable prostheses over conventional complete dentures. The case report aims to address and discuss the clinical and laboratory steps of implant-supported, bar-retained maxillary overdenture and mandibular implant-supported, metal-acrylic resin, screw-retained, fixed complete denture. Impression techniques and laboratory steps are discussed and demonstrated to minimize the post-fabrication or insertion complication. It lets you achieve the passive fit of the prosthesis that maintains the osseointegration by reducing stress on implants and the surrounding bone.

Clinical Peri-Implant Parameters and Marginal Bone Loss for Early Mandibular Implant Overdentures: A Follow-Up of 60 Months.

Background and Objectives: Despite the identified benefits of early implant loading, studies have questioned its advantages compared to delayed loading in edentulous patients. This study aimed to evaluate clinical peri-implant parameters and marginal bone loss around early placed and loaded mandibular implant overdentures with a 60-month follow-up. Materials and Methods: In this prospective cohort study, 43 patients were enrolled to receive 86 early loading sub-crestal dental implants through prosthetic guides. Implant overdentures were supported by two isolated implant locator attachments between two mental foramens. Clinical peri-implant parameters, including plaque index (PI), bleeding index (BI), peri-implant pocket depth (PIPD), and marginal bone loss (MBL) were evaluated using standardized techniques at 1, 12, 24, 36, 48, and 60 months follow-up. At 60 months, complications associated with implant overdentures (IOD's) were noted. The mean comparison of peri-implant clinical parameters was performed through ANOVA test. A p-value of ≤0.05 was taken as significant. Results: Out of the total 43 enrolled patients, 8 patients were lost during follow-up; as a result, 35 patients completed the 5 years follow-up. The mean values of PI, BI, and PIPD increased with no statistical difference (p > 0.05). For marginal bone loss, an increase in the mean values was noted at different time intervals with statistical differences (p < 0.001). The most common complications noted were loosening of the abutment, occlusal adjustment, retentive locator loosening and replacement, and relining of the denture. Conclusions: Early placement of IODs failed to prevent bone loss over time and was associated with complications, predominantly consisting of abutment loosening, occlusal adjustments, broken retentive locator components, relining, and rebasing.

Changes in masticatory performance and bite force after treatment with mandibular overdentures retained by four titanium-zirconium mini implants: One-year randomised clinical trial.

OBJECTIVE: This prospective study is part of a randomised clinical trial and reports the changes in masticatory performance (MP) and bite force, and explores their influential factors, 1 year after the provision of mandibular overdentures retained by four titanium-zirconium mini implants. METHODS: Edentulous patients received conventional complete dentures, followed by placement of four mini implants (Straumann® Mini Implant System) in the anterior mandible and converting the conventional prosthesis into a mandibular overdenture. Treatment protocols were randomised using a 2×2 factorial design combining different surgical (flapped vs. flapless) and loading (immediate vs. delayed) protocols. MP was assessed using a two-colour mixing ability test and a colorimetric analysis to measure the level of colour mixing (Variance of Hue-VoH). Maximum voluntary bite force (MBF) was measured by a digital gnathodynamometer in the posterior and anterior regions. Sex, age, surgical and loading protocols and ridge morphology were tested as independent variables. MP and MBF tests were performed at baseline (pre-treatment) and the 3-, 6- and 12-month after implant loading. Descriptive statistics, independent t-test, and linear mixed-effect model (LMM) regression were used for data analysis. RESULTS: Seventy-four participants were assessed and 73 completed the 1-year follow-up. Statistically significant improvements in functional parameters were observed in all follow-up periods compared to baseline (p < .001). The flapless protocol was associated with higher improvement in MP at the 3-month follow-up (p = .004), while less resorbed ridges were associated with better MP (p = .038) and higher MBF (p < .001). CONCLUSION: The mandibular overdenture protocol using four titanium-zirconium mini implants was effective in improving MP and MBF of edentulous patients, compared to pre-treatment values. The findings also suggest that improvements in chewing function and bite force are impacted by clinical factors since better outcomes were observed for flapless surgeries and less resorbed edentulous ridges. CLINICAL TRIAL REGISTRATION: ClinicalTrials.Gov ID NCT04760457.

3D printing vs traditional workflow for the fabrication of mandibular implant overdentures: study protocol for a mixed-methods cross-over RCT.

BACKGROUND: Complete tooth loss is a significant global oral health issue, particularly impacting older individuals with lower socioeconomic status. Computer-assisted technologies enhance oral healthcare access by the elderly. Despite promising in vitro reports on digital denture materials, evidence from randomized clinical trials (RCTs) is lacking to verify their performance. This cross-over RCT will investigate whether 3D-printed implant-retained mandibular overdentures (IMO) are more satisfactory for edentulous seniors than those made through traditional methods. METHODS/DESIGN: We will recruit 26 completely edentulous participants (any sex/gender) based on the following eligibility criteria: age ≥ 60 years, no tooth extraction in the past 12 months, two implants in the lower jaw, and need for new dentures in both jaws. Each participant will receive two denture pairs, either manufactured by 3D printing or traditionally, to be worn in a random order. A timeline of 3 months with each denture pair will be considered for outcome assessment (total: 6 months). Patient satisfaction with dentures will be measured by the McGill Denture Satisfaction Questionnaire. We will evaluate other patient-reported outcomes (including oral health-related quality of life) as well as clinician-assessed quality and cost. At the end of the trial, participants will choose which denture pair they wish to keep and interviewed about their experiences with the 3D-printed IMO. The quantitative and qualitative data will be incorporated through an explanatory mixed-methods strategy. A final quantitative assessment will happen after 12 months with the preferred IMO to assess the long-term performance and maintenance needs. DISCUSSION: This mixed-methods RCT will explore patient experiences with 3D-printed IMOs, aiming to assess the potential for altering clinical practice and dental public health policies. Our results will inform policies by showing whether 3D printing offers comparable outcomes at lower costs, facilitating greater access to oral care for the elderly. TRIAL REGISTRATION: ClinicalTrials.gov, NCT06155630, Registered on 04 December 2023. https://classic. CLINICALTRIALS: gov/ct2/show/NCT06155630.

Enhancing oral function: A case report on mandibular overdenture utilization with custom-made subperiosteal implant.

Subperiosteal implants, previously set aside because of complications, are now emerging again as effective treatments for severe mandibular atrophy, aided by recent improvements in digital dentistry. Traditional dentures in such cases often face challenges with support and retention, necessitating complex regenerative procedures. This paper presents a case report of a 54-year-old male patient with significant mandibular atrophy who received a custom-made subperiosteal implant, showcasing promising results. The implant was precisely designed utilizing computed tomography (CT) scans, a 3D-printed model, the selective laser melting (SLM) technique, and constructed with biocompatible Ti6Al4V material. This innovative approach offered a practical solution, resulting in high patient satisfaction and no complications over a year of use.

Fabrication of a mandibular implant-retained overdenture using an existing subperiosteal implant: A clinical report.

A 64-year-old edentulous woman with a mandibular fracture received a subperiosteal implant for fracture fixation and dental rehabilitation. However, the ball abutments were submerged by the soft tissue because they were too short. Therefore, we designed a connector to lengthen the attachment and achieve adequate stability and retention for the overdenture.

Efficacy of antimicrobial photodynamic therapy in reducing oral yeasts growth in individuals wearing implant overdentures: A systematic review of clinical trials.

OBJECTIVE: The aim was to systematically review clinical studies that investigated the efficacy of antimicrobial photodynamic therapy (aPDT) in reducing oral yeasts growth (OYG) in individuals wearing implant overdentures (IO). METHODS: The focused question was "Is aPDT effective in reducing OYG in patients wearing IO?" Literature search was performed in accordance with PRISMA guidelines. Indexed databases were searched without time and language restrictions up to and including January 2024. Clinical studies were included; and letters to the Editor, case-reports/case-series, perspectives/commentaries, in-vitro/ex-vivo studies, studies on animal models and expert opinions were excluded. The risk of bias was also assessed. RESULTS: Two clinical studies were included and processed for data extraction. The study population comprised of 100 (mean age: 58.5 years) and 53 (mean age: 58.5 years) individuals. The numbers of males and females included in these studies ranged between 33 and 35 males and 18-67 females, respectively. In both studies, follow-up evaluations were performed after 60 days. In both studies, aPDT was performed using a 660 nm diode laser at a power of 100 mW and using methylene-blue as photosensitizer. Results from both studies showed that aPDT is effective in significantly reducing oral yeasts CFU/ml and improvement of OHRQoL of individuals using IO. CONCLUSION: The aPDT is useful in reducing OYG on IO; however, further well-designed and power-adjusted studies are needed in this area of research.

Immediate versus Non-immediate Loading Protocols for Reduced-diameter Implants Supporting Overdentures: A Systematic Review and Meta-analysis.

OBJECTIVE: This systematic review aimed to compare the influence of immediate and non-immediate loading protocols on overdentures retained by reduced-diameter implants(≦3.5mm). METHODS: Electronic databases, including MEDLINE (via PubMed), Embase and the Cochrane Central Register of Controlled Trials were searched for randomized controlled trials (RCTs) comparing clinical outcomes of immediately and nonimmediately loaded reduced-diameter implants supported overdentures. The risk of bias within and across the studies and the certainty of evidence were assessed by RoB 2.0 and GRADE, respectively. Sensitivity analysis was performed by eliminating studies at high risk of bias, and repeating the data synthesis employing the randomeffect model. Subgroup analyses were conducted based on the implant diameter and the length of follow-up. RESULTS: Six RCTs with 255 patients were included in this systematic review. The meta-analyses found similar implant survival rates between immediate and nonimmediate loaded implants in mini implant (RR=0.98; 95% CI=0.95, 1.01; p=0.12) and narrow implant subgroups (RR=0.99, 95% CI=0.94, 1.03, p =0.56), as well as in short-term (RR=0.98, 95% CI=0.97, 1.00, p =0.11) and long-term (RR=0.97, 95% CI=0.93, 1.01, p =0.09) follow-up subgroups. Additionally, marginal bone loss (MBL) showed no statistically significant difference between the loading protocols in the subgroup of long-term follow-up (MD=0.03; 95%CI=-0.16, 0.23; p=0.74). Three RCTs investigating peri-implant parameters found relatively higher modified plaque index and probing depth in reduced-diameter implant under immediate loading. CONCLUSION: Compared with non-immediate loading, the immediately loading protocol can achieve comparable survival rates and MBL in reduced-diameter implant retained overdentures.

Single lateral implant for mandibular overdentures as a fallback solution or a viable treatment alternative: Four case reports.

This report of four clinical cases aims to illustrate the use of a lateral implant as a solution for implant overdentures in the mandible in different clinical situations. The first two cases describe the clinical situations of patients wearing two-implant mandibular overdentures until the failure of one of the implants, one due to implant loss and the other due to a fracture of an abutment screw, and how the conditions were managed. The third case illustrates the placement of a single implant to retain an overdenture, where a midline implant, as originally planned, was not feasible due to anatomic reasons. The final case describes the use of a lateral implant to support and retain a single-implant mandibular overdenture. The four cases demonstrate that a single lateral implant can be utilized as sole retention in cases of a failing contra-lateral implant and as an alternative to a single implant in the midline.

Mandibular Overdenture Supported by Two or Four Unsplinted or Two Splinted Ti-Zr Mini-Implants: In Vitro Study of Peri-Implant and Edentulous Area Strains.

Clinical indications for the newly released Ti-Zr (Roxolid®) alloy mini-implants (MDIs) aimed for overdenture (OD) retention in subjects with narrow alveolar ridges are not fully defined. The aim of this study was to analyze peri-implant and posterior edentulous area microstrains utilizing models of the mandible mimicking a "real" mouth situation with two (splinted with a bar or as single units) or four unsplinted Ti-Zr MDIs. The models were virtually designed from a cone beam computed tomography (CBCT) scan of a convenient patient and printed. The artificial mucosa was two millimeters thick. After MDI insertion, the strain gauges were bonded on the oral and vestibular peri-implant sites, and on distal edentulous areas under a denture. After attaching the ODs to MDIs, the ODs were loaded using a metal plate positioned on the first artificial molars (posterior loadings) bilaterally and unilaterally with 50, 100, and 150 N forces, respectively. During anterior loadings, the plate was positioned on the denture's incisors and loaded with 50 and 100 N forces. Each loading was repeated 15 times. The means with standard deviations, and the significance of the differences (two- and three-factor MANOVA) were calculated. Variations in the MDI number, location, and splinting status elicited different microstrains. Higher loading forces elicited higher microstrains. Unilateral loadings elicited higher microstrains than bilateral and anterior loadings, especially on the loading side. Peri-implant microstrains were lower in the four-MDI single-unit model than in both two-MDI models (unsplinted and splinted). Posterior implants showed higher peri-implant microstrains than anterior in the four-MDI model. The splinting of the two-MDI did not have a significant effect on peri-implant microstrains but elicited lower microstrains in the posterior edentulous area. The strains did not exceed the bone reparatory mechanisms, although precaution and additional study should be addressed when two Ti-Zr MDIs support mandibular ODs.

Complete Removable Denture Retained by a Symphyseal Single Implant: A Case Report.

Complete denture is a real challenge for any practitioner. The aim of implantology is to optimize prosthetic balance and ensure that prostheses are perfectly integrated from a bio-functional viewpoint, despite an unfavorable anatomophysiological context. Here, we present a case managed in our department concerning a mandibular complete removable denture retained by a medial symphyseal implant. A 61-year-old fully edentulous mandibular patient with a Kennedy Applegate class I edentulous maxilla in good general health consulted for the renewal of his mandibular complete denture, which was deemed unstable and non-retentive. The exo-oral examination was normal. The mandibular crest was heavily resorbed, especially posteriorly, and covered with slightly inflammatory fibromucosa. The patient refused bone augmentation surgery. We performed a piezographic mandibular prosthesis retained by a single standard implant at the level of the mandibular symphysis. The prosthesis was stable and retentive. Masticatory comfort and efficiency were satisfactory and the psychological integration of the prosthesis was improved. Several studies have shown that a single symphyseal implant is a therapeutic alternative that completes the therapeutic range in specific cases. It should be limited to the mandibular arch in elderly patients with reduced bone volume. Given the lack of randomized controlled trials, routine use of this new approach is not recommended, and further studies are required.