The number of implants required to support a maxillary overdenture: a systematic review and meta-analysis

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 postfabrication 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.

Prediction of lifespan and assessing risk factors of large-sample implant prostheses: a multicenter study

PURPOSE

This study aimed to analyze factors influencing the success and failure of implant prostheses and to estimate the lifespan of prostheses using standardized evaluation criteria. An online survey platform was utilized to efficiently gather large samples from multiple institutions.

MATERIALS AND METHODS

During the one-year period, patients visiting 16 institutions were assessed using standardized evaluation criteria (KAP criteria). Data from these institutions were collected through an online platform, and various statistical analyses were conducted. Risk factors were assessed using both the Cox proportional hazard model and Cox regression analysis. Survival analysis was conducted using Kaplan-Meier analysis and nomogram, and lifespan prediction was performed using principal component analysis.

RESULTS

The number of patients involved in this study was 485, with a total of 841 prostheses evaluated. The median survival was estimated to be 16 years with a 95% confidence interval. Factors found to be significantly associated with implant prosthesis failure, characterized by higher hazard ratios, included the 'type of clinic', 'type of antagonist', and 'plaque index'. The lifespan of implant prostheses that did not fail was estimated to exceed the projected lifespan by approximately 1.34 years.

CONCLUSION

To ensure the success of implant prostheses, maintaining good oral hygiene is crucial. The estimated lifespan of implant prostheses is often underestimated by approximately 1.34 years. Furthermore, standardized form, online platform, and visualization tool, such as nomogram, can be effectively utilized in future follow-up studies.

An implant-supported overdenture for a mandibular defect after tumor resection guided by 3-dimensional finite element analysis: A clinical report

This clinical report describes the rehabilitation of a mandibular defect after tumor resection with an implant-supported overdenture and the attachment selection as guided by 3-dimensional finite element analysis. Autologous bone grafting was declined by the patient who demanded the restoration of lateral appearance and mastication function. Three implants were placed based on the condition of the bone, and a satisfactory definitive prosthesis was provided that corresponded with the results of the finite element analysis.

Vertical versus angled immediately loaded implants for assisting maxillary overdentures with locator attachments: A preliminary results of one-year randomized clinical trial

OBJECTIVES

This study aimed to evaluate the clinical outcomes and patient satisfaction of 4-implant-assisted maxillary overdentures using two different designs.

MATERIALS AND METHODS

Thirty edentulous participants received four implants in the maxillary ridge. The patients were randomly divided into two equal groups: (1) the control (CG, Vertical) group (n = 15); participants received four vertical implants with straight locator attachments to retain maxillary overdentures, and (2) the study (SG, Angled) group (n = 15); participants received four angled implants with angled locator attachments to retain maxillary overdentures. Peri-implant tissue health [Plaque (PL) and gingival (GI) indices, pocket depth (PD), implant stability (ISQ) and crestal bone loss (CBL)] were evaluated after denture insertion (T0), 6 (T6), and 12 (T12) months after insertion. Patient satisfaction was evaluated using a visual analog scale (VAS) after 12 months.

RESULTS

The survival rates were 96.7% and 95% for the control and study groups respectively. PL, GI, and PD increased significantly in both groups with the passage of time. No significant difference in PL, GI, PD, and ISQ was noted between groups at all observation times. CG showed higher CBL than SG at T12. For the VAS results, there was no significant difference between groups. SG recorded significantly higher satisfaction regarding comfort with maxillary and mandibular dentures, retention of mandibular dentures, oral hygiene, the ability to chew hard food, and occlusion than CG.

CONCLUSION

Within the limitations of this study, angled implants with angled locator attachments may be recommended to retain maxillary overdentures opposing intact dentition or fixed restoration as it was associated with improvements of several parameters of peri-implant tissue health and patient satisfaction compared to vertical implants with straight locator attachments.

HIF-1α increases the osteogenic capacity of ADSCs by coupling angiogenesis and osteogenesis via the HIF-1α/VEGF/AKT/mTOR signaling pathway

BACKGROUND

Stabilization and increased activity of hypoxia-inducible factor 1-α (HIF-1α) can directly increase cancellous bone formation and play an essential role in bone modeling and remodeling. However, whether an increased HIF-1α expression in adipose-derived stem cells (ADSCs) increases osteogenic capacity and promotes bone regeneration is not known.

RESULTS

In this study, ADSCs transfected with small interfering RNA and HIF-1α overexpression plasmid were established to investigate the proliferation, migration, adhesion, and osteogenic capacity of ADSCs and the angiogenic ability of human umbilical vein endothelial cells (HUVECs). Overexpression of HIF-1α could promote the biological functions of ADSCs, and the angiogenic ability of HUVECs. Western blotting showed that the protein levels of osteogenesis-related factors were increased when HIF-1α was overexpressed. Furthermore, the influence of upregulation of HIF-1α in ADSC sheets on osseointegration was evaluated using a Sprague-Dawley (SD) rats implant model, in which the bone mass and osteoid mineralization speed were evaluated by radiological and histological analysis. The overexpression of HIF-1α in ADSCs enhanced bone remodeling and osseointegration around titanium implants. However, transfecting the small interfering RNA (siRNA) of HIF-1α in ADSCs attenuated their osteogenic and angiogenic capacity. Finally, it was confirmed in vitro that HIF-1α promotes osteogenic differentiation and the biological functions in ADSCs via the VEGF/AKT/mTOR pathway.

CONCLUSIONS

This study demonstrates that HIF-1α has a critical ability to promote osteogenic differentiation in ADSCs by coupling osteogenesis and angiogenesis via the VEGF/AKT/mTOR signaling pathway, which in turn increases osteointegration and bone formation around titanium implants.

Maxillary implant overdenture retained by four unsplinted attachments and opposed by a natural or fixed dentition: Five-year clinical outcomes. A prospective case series

OBJECTIVES

The objective of this study was to assess, over a period of 5 years, implant prosthesis and patient-reported outcomes of complete dentures retained by four implant-supported attachments in the edentulous maxilla facing either natural teeth or fixed rehabilitation in the lower jaw.

MATERIALS AND METHODS

Implant, prosthodontic and patient-related outcomes were assessed in 30 patients at 1, 3 and 5 years. Prosthodontic survival, complications or maintenance events as well as implant survival were recorded. Patient-reported outcome measures (PROMs) were evaluated with the Oral Health Impact Profile (OHIP-20) questionnaire and a visual analogue scale (VAS) before implant placement (baseline) and during the follow-up period.

RESULTS

After 5 years, three patients dropped out, 21 implants failed, and four overdentures were replaced leading to a prosthesis survival rate of 85.2% (95% CI: 71.8%-98.6%) and an implant survival rate of 80.6% (95% CI: 73.1%-88.0%). Prosthodontic success rate decreased from 86.2% to 74% between the 1st and the 3rd year and reached 63% after 5 years. OHIP results improved significantly from baseline to 1 year (p < .0001) and to 3 years (p = .036), but, at 5 years, the improvement was no longer significant when compared to baseline (p = .12). The overall VAS score remained significantly higher up to 5 years (p < .001).

CONCLUSION

A substantial number of prosthetic complications and replacements occurred over the 5-year follow-up. After 5 years, the OHIP-20 deteriorated and reached again the baseline level. Nonetheless, the VAS results suggest significantly increased patient satisfaction after implant-supported retention was provided for the removable prostheses.

Maxillary overdenture on three implants retained by low-profile stud attachments - A prospective cohort study

BACKGROUND

Clinical data are needed on long-term outcomes of removable implant-supported prostheses in the fully edentulous maxilla as a function of the number of implants, effects of the attachment system and other clinical variables.

OBJECTIVE

To restore individuals with an edentate maxilla with a metal-reinforced removable prosthesis without palatal coverage retained by low-profile stud attachments on three implants.

METHODS

The regional ethics committee approved a prospective cohort study that included all consecutive patients treated in a private speciality clinic. Primary outcomes were patients reported, that is denture satisfaction scale and oral health-related quality of life - OHIP-20. Secondary outcomes were implant- (bone loss, implant complications and peri-implant conditions) and prosthesis-related (prosthesis complications, maintenance needs and mucosa condition).

RESULTS

Thirty-two study participants were recruited between March 2007 and October 2016 and followed for a minimum of five years. According to Kruskal-Wallis tests, the OHIP-20 and Denture Satisfaction Scale questionnaire pre-treatment scores differed significantly. After an average of 6.7 years, peri-implant bone loss of more than 2 mm was observed on 17% of all implants, while no or minor bone loss was seen on 38%. The estimated success of implants was 0.95 at 168 months. The estimated success of the prosthesis, that is no adverse events or need for any repairs, was 0.55 at 156 months.

CONCLUSION

The positive findings in the current clinical study strengthen the notion that for many individuals with an edentulous maxilla, a removable prosthesis retained by three implants fitted with low-profile stud-attachment is a reliable technical solution.

Maxillary bar overdentures on four or six posterior implants: 10-year results from a randomized clinical trial

OBJECTIVE

To compare clinical and patient-reported outcomes when providing maxillary overdentures on four and six splinted implants placed in the posterior region during a 10-year follow-up period.

MATERIALS AND METHODS

Sixty-six edentulous participants with functional maxillary denture complaints and insufficient bone volume to allow implant placement were scheduled for a bone augmentation procedure. After healing, participants were randomized to receive either four or six implants in the posterior maxilla. After 3 months of osseointegration, a bar overdenture was constructed. Implant survival, overdenture survival, clinical scores, peri-implant bone height changes, and patient satisfaction were assessed.

RESULTS

Forty-six participants completed the 10-year follow-up. Implant survival was 100% in the 4-implant group and 96.7% in the 6-implant group. Seven new overdentures were made in the 4-implant group and 12 new overdentures were made in the 6-implant group due to excessive wear of the denture base and teeth. Clinical parameters did not differ significantly between groups. Mean marginal bone loss compared to baseline was 0.41 ± 0.37 mm in the 4-implant group and 0.70 ± 1.07 mm in the 6-implant group. Overall, patient satisfaction improved significantly, but did not differ between groups.

CONCLUSION

From this 10-year follow-up trial, it was concluded that bar maxillary overdentures on four or six implants in the posterior region of an augmented maxilla resulted in a comparable treatment outcome with high implant survival, limited loss of peri-implant marginal bone, and high patients' satisfaction. (Clinical trial registration number: NTR9729).

Prosthodontic Treatment in Patients with Temporomandibular Disorders and Orofacial Pain and/or Bruxism: A Review of the Literature

Temporomandibular disorders are a group of conditions affecting the temporomandibular joints, the jaw muscles, and related structures. Patients with temporomandibular signs and/or symptoms frequently present with indications for prosthetic treatment. The management of these patients aims to achieve patient comfort, occlusal stability, and the complex restoration of the teeth. The goal of this review is to provide an overview of the relationship between prosthodontics and temporomandibular disorders and/or bruxism with a focus on the cause-and-effect implications and the strategies for planning prosthetic treatments in patients with temporomandibular disorders and/or bruxism.

Prosthetic failures in dental implant therapy

Both fixed and removable implant-supported prostheses are well-established methods for replacing missing teeth in partially or fully edentulous patients. Numerous systematic reviews have been performed in recent years to evaluate the survival and complication rates of implant-retained fixed dental prostheses and implant-retained overdentures, displaying high 5-year survival rates ranging from 97.1% for fixed dental prostheses to 95%-100% for implant-retained overdentures. However, the survival rates only represent the prostheses remaining in use for a defined follow-up time, and do not account for the potential prosthetic complications that may have arisen and influence the general success of the implant treatment. The most common technical complications of fixed implant-retained single crowns are crown fracture, fractures of ceramic implant abutments, and esthetic problems. The predominant technical complication at multiple-unit, implant-retained fixed dental prostheses is fracture/chipping of the veneering ceramic. Reported technical complications for implant-retained overdentures are overdenture fracture or chipping of the veneer materials, whereas mechanical complications include implant fracture, attachment failure, and attachment housing or insert complications. To reduce the risk of such failures, a comprehensive pretreatment diagnostic work-up is essential, including defining the prosthetic goal with the aid of a wax-up or set-up and the associated ideal, prosthetically oriented three-dimensional implant position. Furthermore, selection of the ideal type of prosthesis, including the respective implant components and materials, is important for clinical long-term treatment success.

Maxillary implant overdentures on two or four implants. A prospective randomized cross-over clinical trial of implant and denture success and survival

OBJECTIVES

To determine implant survival and success of four conventionally but initially asynchronously loaded implants in implant-supported overdentures for the edentulous maxilla, in participants with opposing mandibular two-implant overdentures.

MATERIAL AND METHODS

Twenty-six participants received four implants in the region of the maxillary canines and molars. After healing, 24 of these participants (mean age: 68.3 years) were randomly allocated to one of two treatment groups, and the adapted overdenture was attached to two unsplinted cylindrical attachments. The other two matrixes remained unattached to the implants for 3 months. After this period, the other two implants were loaded for 3 months (cross-over design). Then, all four implants were loaded for another 3 months. Kaplan-Meier curves were used to evaluate survival and success of implants and dentures.

RESULTS

During the active prosthetic study phase, three participants lost one implant. Two participants lost three implants during the recall period. Implant survival after loading was 93.8% after a mean observation period of 3.1 years. Denture survival was 100%, but denture success was 95.8%, due to major prosthetic complications. Most participants preferred four implants to two.

CONCLUSIONS

Within the limitations of the study, it can be concluded that maxillary implant overdentures on two or four implants are both recommendable treatment options. Two posterior implants are not superior to two anterior implants under overdentures retained by unsplinted cylindrical attachments. Implant and prosthetic complications and aftercare measures are common but are mostly easy to handle. However, 23 of the 24 participants preferred the 4-implant maxillary overdenture.

Four-implant-supported overdenture treatment in the maxilla. Part I: A randomized controlled split mouth trial assessing the effect of microthreads and abutment connection type on 4 years peri-implant health

BACKGROUND

According to literature, peri-implant bone loss is minimized on implants with microthreaded neck design and internal type of abutment connection. However, most clinical studies may be biased due to confounding factors.

PURPOSE

This nonblinded RCT assessed the effect of implant neck (microthreaded vs non-microthreaded) as well as the type of abutment connection (internal conical vs external flat-to-flat) on peri-implant bone stability and peri-implant health after at least 36 months.

MATERIALS AND METHODS

Twenty-five patients were treated with a maxillary implant-supported bar-retained overdenture on four different implant types: internal connection with microthreads (I-MT), internal connection without microthreads (I-NMT), external connection with microthreads (E-MT), and external connection without microthreads (E-NMT). To control confounding factors, all other design features were similar. A linear mixed-model analysis or mixed-model logistic regression analysis was used to determine the effect of implant type on bone level, probing pocket depth, bleeding on probing, and plaque.

RESULTS

Four out of 98 implants (4.1%) placed in 25 patients failed during provisionalization and were replaced. Mean overall bone loss after 6 months was 0.39 mm (SD 0.62, range 0.00-3.48) with limited additional bone loss of 0.04 mm (SD 0.54, range -1.80-1.63) after at least 3 years. Microthreads or connection type had no effect on the bone level, probing pocket depth, bleeding on probing, nor plaque.

CONCLUSIONS

With 96% of implant survival, the maxillary overdenture supported with a bar on four implants yield a predictable outcome and the implant-abutment connection type (internal vs external) and implant neck design (microthreaded vs non-microthreaded) have no influence on peri-implant bone remodeling after initial bone remodeling nor up to 4 years of function. Peri-implant bone levels are within international success standards and peri-implant health is indicative of absence of peri-implantitis.

Four-implant-supported overdenture treatment in the maxilla. Part II: Speech- and oral health-related quality of life in patients with implant-supported overdentures in the maxilla-A prospective 3-year follow-up

BACKGROUND

Implant-supported overdentures (IOD) are becoming a more commonly used treatment in the dental practice and it risks causing speech problems.

PURPOSE

The aim of this study was investigating the changes in speech, satisfaction with speech, and overall oral health-related quality of life (OHRQoL) in edentulous patients during and after treatment with maxillary IODs.

MATERIALS AND METHODS

Twenty-one patients receiving an IOD participated in speech assessment. They were examined preoperatively with their conventional denture (CD) with full palatal coverage, after connection of the implant-bar connected denture, without palatal coverage, and 3 years thereafter. The examination included assessment of articulation in speech, OHRQoL based on total OHIP-14, and satisfaction with overall oral health and speech (visual analogue scale).

RESULTS

There was a reduction in mean number of articulation disorders from 1.00 at baseline to 0.55 at connection, although statistically insignificant (p = 0.059). Especially the /s/ sound is vulnerable. At 3 years follow-up, still 6/16 (37.5%) of the patients suffered from this speech problem. Overall satisfaction improved from 64.05/100 at baseline to 82.95/100 at connection (p = 0.008) and remained unchanged with 81.69/100 after 3 years follow-up. Patients' satisfaction with speech increased from 70.62/100 with CD to 82.63/100, 3 years follow-up (p = 0.009). Total OHIP-14 decreased from 21.45/56 with CD to 8.00/56 (p < 0.001) with IOD and 6.13/56 3 years after connection (p = 0.001). Significant improvement of all seven domains in OHRQoL was observed with IOD compared to CD.

CONCLUSIONS

Patients treated with maxillary IODs show improved OHRQoL 3 years after connection of the IOD compared to the CD. Even though patients reported improvement of satisfaction and OHRQoL, articulation disorders were still present, suggesting that patients should be informed about possible speech issues.

Patient satisfaction and survival of maxillary overdentures supported by four or six splinted implants: a systematic review with meta-analysis

Background

Implant-supported overdentures offer enhanced mechanical properties, which lead to better patient satisfaction and survival rates than conventional dentures. However, it is unclear whether these satisfaction levels and survival rates depend on the number of implants supporting the overdenture. Therefore, this systematic review aimed to compare maxillary overdentures supported by four or six splinted implants in terms of patient satisfaction, implant survival, overdenture survival, and prosthodontic complications.

Methods

Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (PubMed), and EMBASE databases were systematically searched and complemented by hand searching from 2000 to 2019, employing a combination of specific keywords. Studies comparing the use of four versus six implants for supporting overdentures with at least one-year of follow-up after prosthesis installation and including ten fully edentulous patients were included. The risk of bias (RoB) was analyzed with Cochrane’s RoB 2 and Newcastle–Ottawa tools. Implants and prosthesis survival rates were analyzed by random-effects meta-analysis and expressed as risk ratios or risk differences, respectively, and by the non-parametric unpaired Fisher’s test.

Results

A total of 15 from 1865 articles were included, and reported follow-up times after implant placement ranged from 1 to 10 years. Irrespective of the number of implants used, high scores were reported by all studies investigating patient satisfaction. Meta-analysis and non-parametric Fisher’s test showed no statistical differences regarding the survival rate of implants (P = 0.34, P = 0.3) or overdentures (P = 0.74, P = 0.9) when using 4 versus 6 splinted implants to support overdentures, and no significant differences regarding prosthodontic complications were found between groups. Randomized studies presented high RoB and non-randomized studies presented acceptable quality.

Conclusions

Within the limits of this systematic review, we can conclude that the bar-supported overdenture on four implants is not inferior to the overdenture supported by six implants for rehabilitating the edentulous maxilla, in terms of patient satisfaction, survival rates of implants and overdentures, and prosthodontic complications.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01572-6.

Radiographic Evaluation of Prosthodontic Patients

This article focuses on radiographic imaging with regard to planning, treating, and maintaining partially and completely edentulous prosthodontic patients with dental implants. Cone-beam computed tomography (CBCT) is the preferred imaging method for pretreatment dental implant treatment planning. Radiographic guides containing radiopaque materials and/or fiducial markers transfer both the proposed prosthesis design and desired implant location for appropriate radiographic evaluation. The three-dimensional CBCT analysis provides information on the adjacent relevant anatomy, bone volume of the edentulous sites, and restorative space assessment.

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.

Selective Laser Sintering versus Selective Laser Melting and Computer Aided Design - Computer Aided Manufacturing in Double Crowns Retention

Purpose This in vitro study aimed at ascertaining the retention forces for telescopic crowns fabricated with Selective Laser Manufacturing (SLM) and Selective Laser Sintering (SLS) additive technologies, and Computer Aided Design - Computer Aided Manufacturing (CAD-CAM) subtractive technology, by using suitable materials for each.Materials and Methods Full-factorial design was employed for experimental testing, considering the following three factors: (a) inner crown material ‒ technology (zirconia ‒ CAD-CAM; metal-alloy ‒ SLS; metal-alloy ‒ SLM); (b) tooth type (canine or molar); (c) wet vs. dry conditions (i.e. either with or without artificial saliva). The roughness of the inner crowns was analyzed through atomic force microscopy. Three-way analysis of variance (ANOVA) was applied for statistical analysis, followed by Tukey's post-hoc comparisons between the crown types.Results The retention force mean values were between 3.8 N (dry, SLM) and 14.8 N (artificial saliva, SLS), with statistically significant (p<0.001) differences between the three types of inner crowns and interaction with the tooth type. No significant interaction was found between crown or tooth types and the wet vs. dry testing conditions. The zirconia crowns' retention force was significantly (p<0.001) higher compared to similar SLM crowns, with 95% CI (3.62; 5.55) N for the differences. Zirconia was significantly (p<0.001) less retentive compared to similar SLS crowns, with 95% CI (-5.99; -4.06) N for the differences. The roughness decrease and subsequent loss of retention force was the largest in zirconia.Conclusions The SLS inner crowns showed the best retention, followed by zirconia and SLM inner crows.

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

This comprehensive review of the 2019 restorative dental literature is offered to inform busy dentists regarding remarkable publications and noteworthy progress made in the profession. Developed by the Scientific Investigation Committee of the American Academy of Restorative Dentistry, each author brings discipline-specific expertise to 1 of 8 sections of the report: (1) prosthodontics; (2) periodontics, alveolar bone, and peri-implant tissues; (3) implant dentistry; (4) dental materials and therapeutics; (5) occlusion and temporomandibular disorders; (6) sleep-related breathing disorders; (7) oral medicine and oral and maxillofacial surgery; and (8) dental caries and cariology. The report targets important information likely to influence day-to-day dental treatment decisions. Each review is not intended to stand alone but to update interested readers so that they may visit source material when greater detail is desired. As the profession moves toward evidence-based clinical decision-making, an incredible volume of potentially valuable dental literature continues to increase. It is the intention of this review and its authors to provide assistance in negotiating the extensive dental literature published in 2019. It is our hope that readers find this work useful in the clinical management of dental patients.

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.

Retreatment of multiple failing maxillary implants after full arch rehabilitation: a retrospective, observational cohort study

The aim of this study was to assess implant retreatment in a group of patients whose maxillary implants were all failing after full arch rehabilitation. Treatment involved implant removal, augmentation, and placement of an overdenture supported by four to six implants. All consecutive patients referred between 2008 and 2018, following multiple late implant failures in the rehabilitated maxilla, were included in the study. Seventy implants in 15 patients were evaluated at 3.3 ± 2.5 years (range 1.1-8.6 years) after loading. Implant survival, complications, clinical parameters, marginal bone loss, and patient-related outcome measures were recorded at the time of evaluation. Overall implant survival was 95.7%. Three implant failures occurred within the first year of function. Marginal bone loss was 0.32 ± 0.46 mm; pocket probing depth was 4.55 ± 1.59 mm. Plaque, calculus, inflammation, and bleeding were hardly seen (median index score 0). Patients scored their satisfaction with their overdentures as high (mean overall score 8.7 ± 1.2, maximum 10). Chewing soft and tough food was scored as 'good' and hard food as 'moderate'. The mean Oral Health Impact Profile score was 29.5 ± 33.3. It can be concluded that the replacement of multiple failing implants in an edentulous maxilla after bone augmentation is a safe and predictable treatment procedure when applied as an implant-supported overdenture.

Impact of implant superstructure type on oral health-related quality of life in edentulous patients

BACKGROUND

The effect of the type of implant superstructure on oral health-related quality of life (OHRQoL) among edentulous patients remains controversial.

PURPOSE

The purpose of this study is to investigate the association between the type of implant superstructure and OHRQoL.

MATERIALS AND METHODS

Seventy-two completely edentulous patients who received implant fixed complete dentures (IFCDs) or implant overdentures (IODs) were administered the Oral Health Impact Profile (OHIP) questionnaire during the post-treatment maintenance period. The OHIP summary score, as well as the four dimension scores, were calculated to evaluate OHRQoL.

RESULTS

The mean OHIP summary score for the IFCD group tended to be lower than that for the IOD group, but this difference was not statistically significant (19.9 ± 21.9, 22.8 ± 18.2, respectively; P = .57). However, a significant group difference was found in the four dimension scores (P < .01), with the OHIP item scores representing masticatory function being significantly lower in the IFCD group than in the IOD group (P < .05).

CONCLUSIONS

Our results suggested that patients with an IOD exhibited comparable OHRQoL to those with an IFCD, with the exception of perceived masticatory function.

Bar versus ball attachments for maxillary four-implant retained overdentures: A randomized controlled trial

OBJECTIVES

To compare the clinical treatment outcomes of maxillary four-implant retained overdentures with either splinted (bar) attachments or non-splinted (ball) attachments.

MATERIAL AND METHODS

Forty participants who were dissatisfied with their existing conventional maxillary complete dentures were included in this randomized controlled trial. Six months after implant placement, a definitive prosthesis was inserted. Implant success, condition of peri-implant tissue, prosthodontic maintenance and complications, and patient satisfaction were assessed. Outcomes were recorded at baseline, prosthesis delivery, and at 3 and 12 months following prosthesis delivery, and a statistical analysis was performed.

RESULTS

Thirty-two of the forty patients completed the 1-year follow-up and had their treatment outcomes evaluated. The mean marginal bone loss after 1 year of loading was 0.34 ± 0.88 mm, and there were no significant differences between the two groups. Plaque index, gingival index and bleeding on probing were significantly higher in the bar group (p<.001), and the implant success rate of the bar group was significantly lower than that of the ball group (p=.028). The most frequent prosthodontic maintenance and complication issue was the need to change the bar clip or O-ring as a result of retention loss. Patient satisfaction did not differ between the two groups except for aesthetics at 3 months.

CONCLUSIONS

Within the limitations of this study, the maxillary 4-implant retained overdenture exhibited predictable results regardless of the attachment systems (ball or bar) in the 1-year follow-up period. The bar group was more vulnerable than the ball group with respect to maintaining peri-implant tissue health.