Comparative Clinical Study of Conventional Dental Implants and Mini Dental Implants for Mandibular Overdentures: A Randomized Clinical Trial

Patient-reported outcome measures and clinical performance of implant-retained mandibular overdentures with stud and ball attachments: A systematic review and meta-analysis

STATEMENT OF PROBLEM

Evidence regarding the retention system for a mandibular overdenture is important for treatment planning. However, the clinical performance of stud and ball attachments for mandibular overdenture retainers is unclear.

PURPOSE

The purpose of this systematic review and meta-analysis was to compare the clinical performance and self-reported patient outcomes of ball and stud attachments as mandibular overdenture retainers.

MATERIAL AND METHODS

Randomized (RCTs) and nonrandomized (N-RCTs) controlled clinical trials were selected based on the eligibility criteria. The risk of bias was assessed by using the Cochrane Collaboration Tools, and the certainty of the evidence (COE) by using the grades of recommendation, assessment, development, and evaluation (GRADE) workshop approach. Meta-analyses according to the follow-up period were performed for implant survival, prosthetic maintenance and complications, bleeding on probing (BoP), marginal bone loss (MBL), satisfaction, and oral health-related quality of life (OHRQoL).

RESULTS

Thirteen RCTs and 4 N-RCTs were included. Twelve studies presented a high risk of bias. The stud demonstrated a lower risk ratio (RR) (P<.001) for maintenance and complications concerning the need for matrix activation (RR 7.12 [2.65, 19.15]) (very low COE) and new overdentures (RR 2.47 [1.02, 5.96]) (moderate COE), ranging from 1 to 5 years of follow-up. Mean difference (MD) for MBL after 1 (MD 0.40 [0.28, 0.52]; P<.001) and 5 years (MD 0.18 [0.16, 0.20]; P<.001) was higher for ball attachments than that for stud (very low COE) attachments. Stud attachments also improved satisfaction (P<.001) when compared with ball attachments (very low COE). Implant survival rate (high COE), BoP (very low COE), and OHRQoL (low COE) were similar for the attachments.

CONCLUSIONS

Stud and ball attachments are clinically appropriate options as mandibular overdenture retainers and are capable of restoring OHRQoL. Nevertheless, the stud showed greater improvement in satisfaction and less prosthetic aftercare and MBL.

Factors and clinical outcomes for standard and mini-implants retaining mandibular overdentures: A systematic review and meta-analysis

STATEMENT OF PROBLEM

Standard-diameter dental implants are not always applicable because of anatomic limitations of the residual ridge. Thus, mini-implants have been increasingly used and offer an alternative. However, data regarding prosthetic complications, maintenance factors, and clinical outcomes are limited.

PURPOSE

The purpose of this systematic review and meta-analysis was to compare prosthetic complications and maintenance events and clinical outcomes in residual ridges rehabilitated with mandibular implant overdentures (IODs) by using standard implants or mini-implants.

MATERIAL AND METHODS

Nine electronic databases were searched. Quantitative analyses to measure the risk ratio (RR) and standardized mean difference (SMD) were applied. Those methods were used to assess prosthetic complications and maintenance events (abutment adjustments, replacement of retentive element, occlusal adjustment, and overdenture fracture) and clinical outcomes related to postoperative pain, probing depth (PD), plaque index (PI), marginal bone loss (MBL), and implant survival rate.

RESULTS

Altogether, 7 publications were selected. Mini-implants presented reduced abutment adjustments (RR 0.23 [0.07, 0.73], P=.01), replacement of retentive element (RR 0.41 [0.31, 0.54], P<.001), occlusal adjustment (RR 0.53 [0.31, 0.91], P=.02), and overdenture fracture (RR 0.46 [0.23, 0.94], P=.03) compared with standard implants. Additionally, mini-implants presented lower values for PI at 6 months (SMD -0.27 [-0.47, -0.08], P=.006) and 12 months (SMD -0.25 [-0.46, -0.05], P=.01). No additional tangible differences were noted.

CONCLUSIONS

Mini-implants might be an alternative choice based on the number of prosthetic complications and maintenance events. This was also confirmed by the comparable clinical data between standard implants and mini-implants.

Narrow-diameter versus regular-diameter dental implants for mandibular overdentures: A systematic review and meta-analysis

PURPOSE

The aim of this systematic review was to compare treatment outcomes in terms of implant survival rate, marginal bone loss, and patient-reported outcome measures (PROMs) between narrow-diameter implants and regular-diameter implants (RDIs) for mandibular implant overdentures (MIOs).

METHODS

This study was based on the methodology adapted as per Cochrane. Medline, Embase, the Cochrane Central Register of Controlled Trials, Web of Science, and Scopus were searched for pertinent studies published by July 22, 2022. Outcome parameters included in this meta-analysis were implant survival rate, marginal bone loss, visual analogue scale score for patient satisfaction, and value of oral health impact profile.

RESULTS

A total of 782 non-duplicate articles and 83 clinical study registrations were identified from database and hand searches, of which 26 were eligible for full-text searches. Finally, 12 publications reporting on 8 independent studies were included in this review. In the meta-analysis, implant survival rate and marginal bone loss did not significantly differ between narrow-diameter implants and RDIs. Regarding RDIs, narrow-diameter implants were associated with significantly better outcomes in general patient satisfaction and oral health-related quality of life than RDIs for mandibular overdentures.

CONCLUSIONS

Narrow-diameter implants have competitive treatment outcomes compared to RDIs in terms of implant survival rate, marginal bone loss, and PROMs. [Correction added on July 21, 2023, after first online publication: The abbreviation RDIs was changed to PROMs in the preceding sentence.] Thus, narrow-diameter implants might be an alternative treatment option for MIOs in situations with limited alveolar bone volume.

Implant survival/success and peri-implant outcomes of titanium-zirconium mini implants for mandibular overdentures: Results from a 1-year randomized clinical trial

OBJECTIVE

To report the 1-year implant survival/success and peri-implant outcomes of mandibular overdentures retained by four titanium-zirconium mini implants (Straumann® Mini Implant System), and to assess how surgery and loading protocols influence these outcomes.

MATERIALS AND METHODS

A 2 × 2 factorial randomized clinical trial (RCT) tested the combined effects of two loading protocols (immediate or delayed) and two surgical approaches (flapless or flapped) on the success/survival of the mini implants, and peri-implant parameters (plaque, bleeding, sulcus depth, gingival position, and marginal bone loss). Outcomes were assessed up to 1-year after loading, and generalized estimating equations (GEEs) were used to analyze longitudinal and within-patient clustered data.

RESULTS

Two hundred and ninety-six implants were placed in 74 patients. The implant survival/success rates after 1 year were 100%, and no major biological complications were observed. After 1-year, descriptive data suggest no noticeable changes in plaque scores, whilst a reduction in bleeding scores at the 6-month and 1-year follow-ups compared to baseline. Good longitudinal stability was observed for the probing depth and gingival margin height measures. Overall mean marginal bone loss was 0.68 (±0.68) mm after 3 months and 0.89 (±0.75) mm after 1-year. The flapless protocol showed better results on soft tissue stability and health but a slightly higher risk for marginal bone loss.

CONCLUSION

The results of this RCT suggest that mandibular overdentures retained by this novel mini implant system represent a safe and predictable treatment option as confirmed by implant survival/success and peri-implant outcomes, even when flapless surgery and immediate loading protocols are adopted.

Quantitative parameters of digital occlusal analysis in dental implant supported restorative reconstruction recent 5 years: a systematic review

OBJECTIVE

The aims of this systematic review were to evaluate the clinical masticatory performance of implant-supported restorations, observe the occlusal force changes in the distribution of the implant restoration and reveal the positive and negative contributing factors of implant design and components based on the outcomes of digital occlusal measurement.

MATERIAL AND METHODS

An extensive search was conducted through PubMed and CENTRAL to identify clinical trials on implant-retained restorations using digital occlusal analysis methods. Two researchers assessed the identified studies and data extraction independently, and the data synthesis strategies without meta-analysis that summarizes the effect estimates were adopted.

RESULTS

The search screened 3821 titles and abstracts, then full-text analysis for 26 articles was performed, and 14 studies were included in the quantitative synthesis. Four of six studies for implant-retained overdenture showed statistically significant improved bite force when immediate loading (p = .00045, .00005, .00055, and .00005, respectively), and no statistically significant results in the other two studies (p = .225, .371, respectively.) However, the results of the favoured intervention were not statistically significant (p = .104, .166, respectively) in two studies of single posterior implant restorations. In all three studies, the bite force distributed on the implant prostheses of partially fixed implant-retained restoration increased statistically significantly (p = .013, .001, .05, respectively).

CONCLUSIONS

The edentulous restoration supported by implants seems to significantly improves bite force and chewing efficiency compared with conventional dentures. Regular quantitative occlusal measurement is recommended to avoid the possible risk of overload. Smaller implants size and relatively small and flexible attachment designs may be more conducive to the stability and retention of the restoration of atrophy of alveolar bone.

Comparative clinical study of conventional dental implant and mini dental implant-retained mandibular overdenture: A 5- to 8-Year prospective clinical outcomes in a previous randomized clinical trial

AIM

To compare the long-term prospective clinical outcomes in a previous randomized controlled clinical trial (RCT) of 2 Mini Dental Implant (2MDI), 4 Mini Dental Implant (4MDI), and 2 Conventional Dental Implant (2CDI)-retained mandibular overdenture with follow-up between 5 to 8 years.

MATERIALS AND METHODS

Thirty-seven patients formerly participated in the Comparative Clinical Study of CDI and MDI for Mandibular Overdenture were requested for examination of clinical outcomes. A total of 104 implants were placed with mean follow-up periods 6.64 ± 0.60 years. In Group 1 (2MDI) and Group 2 (4MDI), implants were placed and immediately loaded with Equator® attachments to retained mandibular overdenture. In Group 3 (2CDI), implants were placed and delayed 3 months for denture loading with ball attachment. The success rate, survival rate, clinical implant performance scale (CIP scale), peri-implant tissue status, prosthetic complication, implant stability quotient (ISQ), marginal bone level change (MBLC), and patient satisfactions were analyzed.

RESULTS

After 5 to 8 years follow-up, the success rate in Groups 1, 2, and 3 were 90.91%, 93.33%, and 54.55%, respectively. The success rate in Group 3 was significantly lesser than Group 1 (p = 0.016) and Group 2 (p < 0.001). The survival rate in Groups 1, 2, and 3 was 100%, 96.67%, and 90.91%, respectively, and showed no significant differences. Mean ISQ reported no significant differences between groups. Mean MBLC were 0.57 ± 1.19 mm, 0.68 ± 0.90 mm, and 1.55 ± 1.60 mm in Groups 1, 2, and 3, respectively. Group 3 reported significantly greater mean MBLC than Group 1 (p = 0.016) and Group 2 (p = 0.011), but Groups 1 and 2 were not significantly differences. The overall patient satisfactions were reported as not significant differences between groups.

CONCLUDE

Two MDI-retained mandibular overdentures with immediate loaded protocol performed had favorable clinical outcomes, cost effectiveness, and overall patient satisfactions after 5 to 8 years follow-up.

Implant-prosthetic rehabilitation of patients with severe horizontal bone deficit on mini-implants with two-piece design-retrospective analysis after a mean follow-up of 5 years

BACKGROUND

As a consequence of tooth loss due to trauma or extraction, a reduced alveolar crest volume limits the deployment of standard implants in certain patient cases. For this reason, minimal-invasive treatment with mini-dental implants (MDI) might be an option to allow implant treatment even in cases with severe horizontal bone loss without augmentation measures. The aim of this retrospective cohort study was to investigate clinical and radiological implant, as well as patient-related parameters after treatment with MDI.

RESULTS

Clinical and radiological records of 19 female (82.6%) and 4 male patients (17.4%) (N = 23), who received 52 mini-dental implants with a two-piece design in a single surgical center between November 2011 and October 2018, were retrospectively analyzed. Implants were submitted to conventional loading on different types of screwed superstructures. Crestal bone loss was measured on standardized periapical radiographs. Patient-related outcome parameters (PROMs) were recorded during follow-up period. Mean clinical and radiological follow-up was 69.6 months (5.8 years) and 51.6 months (4.3 years), respectively. Three implants were lost in two patients, leading to an implant survival rate of 94.2%. Mean radiological crestal bone loss was 1.6 mm. Both amount of peri-implant recession and crestal bone loss were significantly correlated (r = 0.65; p < 0.001). Likewise, a significant correlation was observed between deeper probing depths and increased peri-implant bone loss (r = 0.41; p = 0.012). Alveolar ridges with a reduced alveolar crest width were significantly correlated with higher peri-implant bone loss as well (r = - 0.33; p = 0.011). No prosthetic complications were reported during follow-up. Extent of midfacial recession and papilla height loss had a significant negative impact on most of the PROMs.

CONCLUSIONS

Treatment with MDI seems to be a successful alternative treatment option, especially for elderly patients with reduced crest width at implant sites. Due to the good clinical results and high survival and success rates, this treatment option was associated with high patient satisfaction. Despite the promising results, particular consideration should be given to appropriate treatment planning in these patients due to the strong correlation between peri-implant soft-tissue parameters, crestal bone loss, and reduced alveolar crest width.

Use of Narrow-Diameter Implants in Completely Edentulous Patients as a Prosthetic Option: A Systematic Review of the Literature

Objective

The objective of the present review is to assess the implant survival, marginal bone loss, and biomechanical features of narrow-diameter implants (2.5-3.5 mm) supporting or retaining full-arch fixed or removable restorations.

Materials and Methods

Three operators screened the literature (PubMed, Cochrane Library, and Google Scholar) and performed a hand search on the main journals that focus on implantology until 24 March 2019. Only articles that considered full-arch restorations supported or retained by narrow-diameter implants (2.5-3.5 mm) were considered if they have a minimum of 10 patients and a mean follow-up of at least 6 months. The outcome variables were survival of implants and marginal bone loss. The review was performed according to the PRISMA statements. Risk of bias assessment was evaluated. Failure rates were analyzed using random effect Poisson regression models to obtain the summary estimate of 5-year survival rate and marginal bone loss.

Results

A total of nine papers were finally selected, reporting a high survival rate of the implants. Eight studies focused only on the mandible while one study reported data from both mandible and maxilla. All studies reported on removable restorations; none focused on fixed rehabilitations. The estimated survival rate for 5 years of follow-up was calculated to be 92.25% for the implants. The estimated marginal bone loss after 5 years was calculated to be 1.40 mm. No study reported implant fractures.

Conclusions

With the limitations of the present study, there is evidence that 2.5-3.5 mm narrow-diameter implants retaining a removable restoration can be a successful treatment in fully edentulous patients. No data on fixed restorations was available.

Mini-Implant-Retained Overdentures for the Rehabilitation of Completely Edentulous Maxillae: A Systematic Review and Meta-Analysis

Purpose: Mini-dental implants (MDIs) have been used to support and retain overdentures, providing patients with a less invasive placement procedure. Although lucrative, the use of MDIs to retain a maxillary overdenture is still not an established treatment modality. This systematic review aims to answer the question: Do mini-implant-retained maxillary overdentures provide a satisfactory treatment outcome for complete edentulism? Methods: A systematic search for relevant articles was conducted to include articles published until April 2021 in the following electronic databases: CINAHL, Cochrane, EMBASE, PubMed, and Web of Science. All empirical studies evaluating the biological, survival, or patient-reported outcomes after placing mini-implant-retained overdentures in maxilla were considered for inclusion. The risk of bias was assessed by utilizing the Joanna Briggs Institute critical appraisal checklist. Study screening and data extraction were conducted by three reviewers independently. Results: The electronic search retrieved 1276 titles after omitting duplicates. Twenty articles were considered for full-text review, of which six studies were included in this systematic review. The included studies evaluated a total of 173 participants with a mean age of 66.3 years. The overall mini-implant survival rate was 77.1% (95% CI: 64.7–89.5%) with a mean follow-up time of 1.79 years (range: 6 months to 3 years). Implant survival differed significantly when comparing complete and partial palatal coverage overdentures. Those with complete palatal coverage exhibited less bone loss overall compared to partial coverage overdentures. Participants of all studies reported an increase in the quality of life and in satisfaction after rehabilitation treatment with MDIs. Conclusions: The survival rate of mini-implants retaining an overdenture in the maxilla was observed to be lower than the values reported for traditional implants in the literature. Improvements were observed in all aspects in terms of patient satisfaction, quality of life, oromyofunction, and articulation after the treatment.

Influence of marginal bone resorption on two mini implant-retained mandibular overdenture: An in vitro study

PURPOSE

To investigate the biomechanical effect of marginal bone resorption (MBR) on the mandibular mini implant (MI)-retained overdenture (MI-OD) on the edentulous model.

MATERIALS AND METHODS

The experimental mandibular edentulous model was modified from a commercial model with 2 mm thick artificial soft tissue under denture base. Two MIs (Φ2.6 mm × 10 mm) were bilaterally placed between the lateral incisor and the canine area and attached with magnetic attachments. Three groups were set up as follows: 1) alveolar bone around the MI without MBR (normal group), 2) with MBR to 1/2 the length of the implant (resorption group), and 3) complete denture (CD) without MI (CD group). Strain around the MI, pressure near the first molar area, and displacement of denture were simultaneously measured, loading up to 50 N under bilateral/unilateral loading. Statistical analysis was performed using independent-samples t test and one-way ANOVA (α=.05).

RESULTS

The strain around the MI with MBR was approximately 1.5 times higher than that without MBR. The pressure in CD was higher than in MI-ODs (P <.05), while there was no statistical difference between the normal and resorption group (P >.05). Similarly, the CD demonstrated a greater displacement of the denture base than did the MI-ODs during bilateral and unilateral loadings (P <.05).

CONCLUSION

The strain around the MI with MBR was approximately 1.5 times higher than that without MBR. The pressure on posterior alveolar ridge and denture displacement of MI-ODs significantly decreased compared to CDs, even when MBR occurs. Bilateral balanced occlusion was recommended for MI-ODs, especially when MBR occurred.

Effects of immediate and delayed loading protocols on marginal bone loss around implants in unsplinted mandibular implant-retained overdentures: a systematic review and meta-analysis

BACKGROUND

Immediate loading has recently been introduced into unsplinted mandibular implant-retained overdentures for the management of edentulous patients due to their increasing demand on immediate aesthetics and function. However, there is still a scarcity of meta-analytical evidence on the efficacy of immediate loading compared to delayed loading in unsplinted mandibular implant-retained overdentures. The purpose of this study was to compare the marginal bone loss (MBL) around implants between immediate and delayed loading of unsplinted mandibular implant-retained overdentures.

METHODS

Randomized controlled trials (RCTs), controlled clinical trials (CCTs), and cohort studies quantitatively comparing the MBL around implants between immediate loading protocol (ILP) and delayed loading protocol (DLP) of unsplinted mandibular overdentures were included. A systematic search was carried out in PubMed, EMBASE, and CENTRAL databases on December 02, 2020. "Grey" literature was also searched. A meta-analysis was conducted to compare the pooled MBL of two different loading protocols of unsplinted mandibular overdentures through weighted mean differences (WMDs) with 95% confidence intervals (95% CIs). The subgroup analysis was performed between different attachment types (i.e. Locator attachment vs. ball anchor). The risk of bias within and across studies were assessed using the Cochrane Collaboration's tool, the Newcastle-Ottawa scale, and Egger's test.

RESULTS

Of 328 records, five RCTs and two cohort studies were included and evaluated, which totally contained 191 participants with 400 implants. The MBL of ILP group showed no significant difference with that of DLP group (WMD 0.04, CI - 0.13 to 0.21, P > .05). The subgroup analysis revealed similar results with Locator attachments or ball anchors (P > .05). Apart from one RCT (20%) with a high risk of bias, four RCTs (80%) showed a moderate risk of bias. Two prospective cohort studies were proved with acceptable quality. Seven included studies have reported 5.03% implant failure rate (10 of 199 implants) in ILP group and 1.00% failure rate (2 of 201 implants) in DLP group in total.

CONCLUSIONS

For unsplinted mandibular implant-retained overdentures, the MBL around implants after ILP seems comparable to that of implants after DLP. Immediate loading may be a promising alternative to delayed loading for the management of unsplinted mandibular implant-retained overdentures. PROSPERO registration number: CRD42020159124.

Narrow-diameter implants versus regular-diameter implants for rehabilitation of the anterior region: a systematic review and meta-analysis

The aim of this systematic review and meta-analysis was to evaluate studies comparing implant survival rates, marginal bone loss (MBL), and mechanical and biological complication rates between narrow-diameter implants (NDIs) and regular-diameter implants (RDIs) used for oral rehabilitation in the anterior region. The review was conducted according to the PRISMA checklist. Two independent reviewers performed a comprehensive search of the PubMed/MEDLINE, Embase, Scopus, and Cochrane Library databases for studies published until May 2020. A total of 843 implants (484 NDIs and 359 RDIs) were included. No significant difference in implant survival rate (risk difference (RD) 0.01, 95% confidence interval (CI) -0.01 to 0.03; P=0.34), MBL (standardised mean difference -0.51mm, 95% CI -1.29 to 0.26mm; P=0.19), mechanical complications (RD 0.01, 95% CI -0.02 to 0.04; P=0.40), or biological complications (RD 0.01, 95% CI -0.09 to 0.11; P=0.85) was found between the implant groups. Within the limitations of this study, it is concluded that NDIs are an effective alternative to RDIs due to similar survival rates, MBL, and mechanical and biological complication rates. However, future studies are highly encouraged due to the small number of interventional studies on this topic.

Computerised occlusal analysis of mini-dental implant-retained mandibular overdentures: A 1-year prospective clinical study

Occlusal analysis is a substantial tool for the functional improvement evaluation after using implant-retained overdenture comparing to complete denture without dental implant retaining. To evaluate occlusal pattern, chewing force distribution in mini-dental implant-retained mandibular overdentures by computerised occlusal analysis system and to compare patient satisfaction after 1-year function. Thirty-one patients wearing complete dentures were included in the study. Prior to mini-dental implant-retained treatment, all patients were assessed for occlusion and force distribution using computerised occlusal analysis system (T-Scan^® ), and then, all patients received two mini-dental implant-retained mandibular overdentures. Mini-dental implants were immediately loaded using low vertical profile attachments (Equator^® ). T-Scan^® was used to evaluate chewing force and force distribution at 1 day, 3 months, 6 months and 12 months. The patient satisfactions before implant placement and after 1 year were evaluated using questionnaires which included satisfaction of denture quality, psychosocial behaviour and chewing efficiency modified from the validated questionnaires. Clinical evaluation of two mini-dental implant-retained mandibular overdentures showed 100% success rate after 1 year. T-Scan^® demonstrated that maximum occlusal contact force increased continuously. The force distribution; the tooth contact number increased over the period. At 1-year follow-up, overall patient satisfaction was significantly greater than before receiving mini-dental implant treatment (P < .001). Using computerised occlusal analysis, mini-dental implants improve complete denture function significantly in terms of maximum occlusal contact force, tooth contact number without the impairment of force distribution. The oral function of the patients has been enhanced.

Tobacco-product usage as a risk factor for dental implants

The oral cavities of tobacco smokers and users of smokeless tobacco products are exposed to high concentrations of nicotine. A limited number of animal studies have assessed the effect of nicotine on osseointegration. Results from experimental studies have reported a statistically significant decrease, at 4 weeks of follow-up, in bone-to-implant contact among rats exposed to nicotine compared with unexposed rats. Nicotine increases the production of inflammatory cytokines (such as interleukin-6 and tumor necrosis factor-alpha) by osteoblasts. Waterpipe, pipe, and cigarette smokers are at increased risk of developing oral cancer, periodontal disease, and alveolar bone loss. One explanation for this is that smokers (regardless of the type of tobacco product) are exposed to similar chemicals, such as nicotine, tar, oxidants, polyaromatic hydrocarbons, and carbon monoxide. Moreover, raised levels of proinflammatory cytokines have been identified in the gingival crevicular fluid of cigarette smokers with peri-implant diseases. Therefore, it is hypothesized that nicotine and chemicals in tobacco smoke induce a state of oxidative stress in peri-implant tissues (gingiva and alveolar bone), thereby increasing the likelihood of peri-implant disease development via an inflammatory response, which if left uncontrolled, will result in implant failure/loss. In this regard, tobacco smoking (including cigarettes, waterpipe, and pipe) is a significant risk factor for peri-implant diseases. The impact of vaping electronic cigarettes using nicotine-containing e-juices remains unknown. Habitual use of smokeless tobacco products is associated with oral inflammatory conditions, such as oral precancer, cancer, and periodontal disease. However, the effect of habitual use of smokeless tobacco products on the success and survival of dental implants remains undocumented.

Clinical evaluation of inter-implant distance influence on the wear characteristics of low-profile stud attachments used in mandibular implant‑retained overdentures

Background

This study was aimed to evaluate the influence of inter-implant distance on the wear characteristics of low-profile stud attachments used in mandibular implant retained overdentures.

Material and Methods

Forty Completely edentulous participants aged between 50 - 70 years were enrolled in this study. Each patient received 2-implants by 2-stage submerged surgical protocol. Participants categorized into 4-groups. Group I: 19 mm inter-implant distance with Locator retained overdentures; Group II: 19 mm inter-implant distance with OT Equator retained overdentures; Group III: 25 mm inter-implant distance with Locator retained overdentures; Group IV: 25 mm inter-implant distance with OT Equator retained overdentures. The female housings of each attachment were picked up to the mandibular overdenture. 12 month later the male inserts were replaced by new one. The used retentive male inserts were examined by Stereomicroscopic.

Results

Stereomicroscopic examination revealed wear were detected on both inner surface and, the core of male inserts. Comparison between the unused and the used Locator and OT equator retentive male inserts at various inter-implant distance revealed highly significant wear changes between them at either 19 mm, or 25 mm inter-implant distance P1= .000, P2=.000 respectively.

Conclusions

After one year of implant overdenture clinical use; both locator and OT equator retentive male inserts revealed significant surface deformities and wear. Wear were more notable on both locator and OT equator retentive male inserts with 25 mm interimplant distance than with 19 mm interimplant distance. Key words:Inter-implant distance, attachments wear, locator retentive male inserts, OT equator retentive male inserts.

Clinical outcome of removable prostheses supported by mini dental implants. A systematic review

INTRODUCTION

For many years, edentulous patients have had no other option than conventional dentures to reestablish their oral function. To avoid the need for bone graft surgery, some professionals have suggested the use of mini dental implants (MDIs) to support prostheses. The MDIs are narrow implants, ranging approximately from 1.8 to 2.9 mm in diameter. Recently, the promising results of mini implants regarding osseointegration and patient satisfaction have led clinicians to accept them as a definitive treatment option.

OBJECTIVE

Therefore, the proposition of this systematic review was to assess information on the outcomes of MDIs supporting removable prostheses.

METHODS

The PubMed and Cochrane databases were searched for articles published before September 2017, which yielded a total of 774 studies for analysis. After exclusion and inclusion criteria, 22 prospective studies were included in this systematic review.

RESULTS

Most mini implants were placed in a flapless single-stage surgery and loaded immediately. Most studies reported failures in the first year and prosthetic complications. The mean survival rate of the selected studies was 95.6%, and mean follow-up was 22.8 months.

CONCLUSION

The MDI-supported removable prostheses successfully improved patients' chewing and speaking ability, quality of life, and satisfaction, suggesting that MDIs are a viable and safe option to support removable prostheses in the mandibular arch.