Different Types Of Prostheses Research Articles

Clinical Evaluation of the Long-Term Survival and Success Rates of Different Types of Implant-Supported Prostheses

ABSTRACT Background: Dental implants have been essential to the therapy of patients who are partially edentulous. Aim: Clinical evaluation of the long-term survival and success rates of different types of implant-supported prostheses. Materials and Methods: Patients who had a healthy edentulous ridge of three missing teeth in the posterior jaw in which two or three dental implants were placed having any of three prostheses, namely, three-unit fixed dental prostheses (FPD) on two implants, three splinted crowns on three implants, and three splinted crowns on three implants were included. Results: The survival rate in all patients with dental implants having different types of prostheses was 94.9%. The survival rate in FPD, three splinted crowns, and three nonsplinted crowns was 100, 88.5, and 93.6% respectively. Conclusion: FPD loaded on two dental implants was found to have a greater long-term survival rate and success rate with a lower frequency of peri-implantitis and prosthodontic complications.

A comparative evaluation of masticatory load distribution in different types of prosthesis with varying number of implants: A FEM analysis

AimTo identify the optimal number and position of implants to reduce stress concentration on the implant, denture, and attachment system for sustaining an overdenture prosthesis. Materials and methodsBy incorporating one to eight indigenous implants with bar-type attachments, eight 3D finite element models of mandibular overdentures were created. All models received a 200 N vertical load, and the biomechanical characteristics of peri-implant bone were assessed. ResultThe study observed that with a vertical load of 200 N, the maximum equivalent stress around peri-implant tissue in all models was within the physiological tolerance threshold of bone. The von Mises stress values ranged from 116.18 MPa to 536.7 MPa. ConclusionThe three-implant-supported overdenture model revealed superior peri-implant stress, stability, cost-effectiveness, and hygiene maintenance outcomes. Placing a third implant in the mid-symphysis region may offer a practical solution to reduce rotations in two-implant-supported overdentures.

Cervical Disc Arthroplasties Fail to Maintain Physiological Kinematics Under Lateral Eccentric Loads.

In vitro human cadaveric biomechanical analysis. Optimization of prostheses for cervical disc arthroplasties (CDA) reduces the risk of complications. The instantaneous helical axis (IHA) is a superior parameter for examining the kinematics of functional spinal units. There is no comprehensive study about the IHA after CDA considering all 3 motion dimensions. Ten human functional spinal units C4-5 (83.2 ± 7.9yrs.) were examined with an established measuring apparatus in intact conditions (IC), and after CDA, with 2 different types of prostheses during axial rotation, lateral bending, and flexion/extension. Eccentric preloads simulated strains. The IHA orientation and its position at the point of rest (IHA0-position) were analyzed. The results confirmed the existing data for IHA in IC. Lateral preloads showed structural alterations of kinematics after CDA: During axial rotation and lateral bending, the shift of the IHA0-position was corresponding with the lateral preloads' applied site in IC, while after CDAs, it was vice versa. During lateral bending, the lateral IHA orientation was inclined, corresponding with the lateral preloads' applied site in the IC and oppositely after the CDAs. During flexion/extension, the lateral IHA orientation was nearly vertical in the IC, while after CDA, it inclined, corresponding with the lateral preloads' applied site. The axial IHA orientation rotated to the lateral preloads' corresponding site in the IC; after CDA, it was vice versa. Both CDAs failed to maintain physiological IHA characteristics under lateral preloads, revealing a new aspect for improving prostheses' design and optimizing their kinematics.

Technical approaches and clinical outcomes of the treatment of temporomandibular dysfunction with prostheses: a systematic review

Introduction: Temporomandibular joint (TMJ) replacement is usually a last resort in the surgical treatment of end-stage joint disease. For all this gear to work efficiently, occlusion, articulation, musculature, ligaments, and psychological factors must be in complete harmony. As a treatment, implantation of a total alloplastic TMJ prosthesis. Objective: It was to demonstrate, through a systematic review, the main considerations and clinical outcomes of the treatment of temporomandibular disorders with different types of prostheses. Methods: The systematic review rules of the PRISMA Platform were followed. The search was carried out from February to April 2023 in the Scopus, PubMed, Science Direct, Scielo, and Google Scholar databases, using articles from 2013 to 2023. Results and Conclusion: A total of 127 articles were found, 60 articles were evaluated and 31 were included and developed in this systematic review study. Considering the Cochrane tool for risk of bias, the overall assessment resulted in 12 studies with a high risk of bias and 33 studies that did not meet GRADE. Based on the results, temporomandibular disorders (TMD) treatment is diverse and depends on the type of disease, as well as the duration and subjective level of pain. Alloplastic reconstruction can be advantageous in obtaining a rapid improvement in symptoms and rapid rehabilitation of masticatory function. Treatment of functional TMD is commonly based on conservative therapy, including physical therapy, pain therapy, and splinting therapy. Depending on the severity of TMD, treatment varies according to the degree of surgical invasion. Thus, the TMJ prosthesis seems to be reserved for patients with persistent pain, bone or fibrous ankylosis, or osteomyelitis after primary closed or open treatment of mandibular condyle fractures. Quality of life, mouth opening, and daily eating improved significantly after total TMJ prosthesis.

FMG-BASED INFORMATION MEASUREMENT SYSTEM FOR CONTROLLING A LOWER LIMB PROSTHESIS

Disability is one of the most pressing health and social problems worldwide. Despite significant medical advances, there are situations in which the only and most effective treatment is amputation. Most often people lose their legs as a result of accidents, wars and industrial injuries. A person's mobility is severely limited by the loss of a lower limb, which has a negative impact on both their physical and emotional health. It definitely reduces the quality of his life. In order for a person who has had an amputation to lead a full and active life in the future, it is necessary to have a well-designed prosthesis that can simulate the normal function of the lost limb as much as possible. There are different types of prostheses with different designs and functions, but the most advanced are those with built-in microprocessors. However, even these prostheses have problems integrating movement and adjusting their operation to the individual characteristics of the patient, which makes it necessary to create and improve modern prosthetic control systems. This research proposes the consideration of an information-measuring system based on the reading of muscle activity signals and their further analysis by means of Fourier transform. As a result, the prosthesis may be controlled more precisely and smoothly, normalizing the biomechanical aspects of human gait. Keywords: Limb prosthesis, amputation, biomedical systems, force myography, signal processing, Fourier transform

Clinical outcomes of various types of revision surgeries after unicompartmental knee arthroplasty failure

PurposeThe advantages of unicompartmental knee arthroplasty (UKA) have led to the procedure being increasingly performed worldwide. However, revision surgery is required after UKA failure. According to the literature review, the choice of implant in revision surgery remains a debatable concern. This study analyzed the clinical results of different types of prostheses used in treating failed UKA.Materials and methodsThis is a retrospective review of 33 failed medial UKAs between 2006 and 2017. Demographic data, failure reason, types of revision prostheses, and the severity of bone defects were analyzed. The patients were classified into three groups: primary prosthesis, primary prosthesis with a tibial stem, and revision prosthesis. The implant survival rate and medical cost of the procedures were compared.ResultsA total of 17 primary prostheses, 7 primary prostheses with tibial stems, and 9 revision prostheses were used. After a mean follow-up of 30.8 months, the survival outcomes of the three groups were 88.2%, 100%, and 88.9%, respectively (P = 0.640). The common bone defect in tibia site is Anderson Orthopedic Research Institute [AORI] grade 1 and 2a (16 versus 17). In patients with tibial bone defects AORI grade 2a, the failure rates of primary prostheses and primary prostheses with tibial stems were 25% and 0%, respectively.ConclusionsThe most common cause for UKA failure was aseptic loosening. The adoption of a standardized surgical technique makes it easier to perform revision surgeries. Primary prostheses with tibial stems provided higher stability, leading to a lower failure rate due to less risk of aseptic loosening in patients with tibial AORI grade 2a. In our experience, we advise surgeons may try using primary prostheses in patients with tibial AORI grade 1 and primary prostheses with tibial stems in patients with tibial AORI grade 2a.

Navigated functional alignment total knee arthroplasty achieves reliable, reproducible and accurate results with high patient satisfaction

PurposeThe decision on which technique to perform a total knee arthroplasty (TKA) has become more complicated over the last decade. Perceived limitations of mechanical alignment (MA) and kinematic alignment (KA) have led to the development of the functional alignment (FA) philosophy. This study aims to report the 2-year results of an initial patient cohort in terms of revision rate, PROMs and complications for Computer Aided Surgery (CAS) Navigated FA TKA.MethodsThis paper reports a single surgeon’s outcomes of 165 consecutive CAS FA TKAs. The final follow-up was 24 months. Pre-operative and post-operative patient-reported outcome measures, WOMAC and KSS, and intra-operative CAS data, including alignment, kinematic curves, and gaps, are reported. Stress kinematic curves were analysed for correlation with CAS final alignment and CAS final alignment with radiographic long-leg alignment. Pre- and post-operative CPAK and knee phenotypes were recorded. Three different types of prostheses from two manufacturers were used, and outcomes were compared. Soft tissue releases, revision and complication data are also reported.ResultsMean pre-operative WOMAC was 48.8 and 1.2 at the time of the final follow-up. KSS was 48.8 and 93.7, respectively. Pre- and post-operative range of motion was 118.6° and 120.1°, respectively. Pre-operative and final kinematic curve prediction had an accuracy of 91.8%. CAS data pre-operative stress alignment and final alignment strongly correlate in extension and flexion, r = 0.926 and 0.856, p < 0.001. No statistical outcome difference was detected between the types of prostheses. 14.5% of patients required soft tissue release, with the lateral release (50%) and posterior capsule (29%) being the most common.ConclusionCAS FA TKA in this cohort proved to be a predictable, reliable, and reproducible technique with acceptable short-term revision rates and high PROMs. FA can account for extremes in individual patient bony morphology and achieve desired gap and kinematic targets with soft tissue releases required in only 14.5% of patients.Level of evidenceIV (retrospective case series review).

Analysis of wear surfaces on parts of revisionally removed implants

Nowadays, with increasing average age - and thus an increase in active years - and the heightened pace of life in our cruel, fast-paced world, our bodies are subjected to extreme stress for ever-longer periods. Unfortunately, this lifestyle does not go away without a trace - it can cause damage to everything from our skeletal system to our nervous system, and our joints are no exception - which is why arthroplasty procedures are becoming increasingly popular. Arthroplasty is one of the most successful surgical procedures, which seeks to re-condition, replace - in some cases remove - the joint surfaces to improve the function of the system or at least preserve its current status. The most common form of arthroplasty is the implantation of joint endoprostheses. These devices have a finite lifespan, like all engineering structures, so their replacement at certain intervals, by means of revision surgery, is essential. The prostheses removed in this way carry a wealth of essential information about their design, their manufacturer and even their user and implantor, which can be incorporated into the design of the next generation of systems using reverse engineering, thus moving closer to the development of the "gold standard" implant. The topic of our article is the analysis and exploration of the failure processes of hip, knee, and shoulder implants removed by revision. We will build a model that adequately represents the wear and tear processes of different types of prostheses, with the help of which the wear and tear processes can be determined and predicted, and the strengths and weaknesses of the constructs can be determined. We consider it essential to distinguish between the different types of damage since, without a comprehensive knowledge of their extent, it is impossible to prevent them effectively. Systems grouped according to implant type and implant modality were examined using 3-dimensional imaging. We determined the degradation of the polymer components caused by use, observing to distinguish between damage caused by revision surgery and damage caused by transportation and storage. During our measurements, particular care was taken to identify the exact extent of creep and wear in order to make the best possible recommendations for modifications to existing systems.

Imaging in Hip Arthroplasty Management Part 2: Postoperative Diagnostic Imaging Strategy.

Hip arthroplasty (HA) is a frequently used procedure with high success rates, but 7% to 27% of the patients complain of persistent postsurgical pain 1 to 4 years post-operation. HA complications depend on the post-operative delay, the type of material used, the patient’s characteristics, and the surgical approach. Radiographs are still the first imaging modality used for routine follow-up, in asymptomatic and painful cases. CT and MRI used to suffer from metallic artifacts but are nowadays central in HA complications diagnosis, both having their advantages and drawbacks. Additionally, there is no consensus on the optimal imaging workup for HA complication diagnosis, which may have an impact on patient management. After a brief reminder about the different types of prostheses, this article reviews their normal and pathologic appearance, according to each imaging modality, keeping in mind that few abnormalities might be present, not anyone requiring treatment, depending on the clinical scenario. A diagnostic imaging workup is also discussed, to aid the therapist in his imaging studies prescription and the radiologist in their practical aspects.

Surgical pulmonary valve replacement at a tertiary adult congenital heart centre in the current era

BackgroundSurgical pulmonary valve replacement (PVR) is the standard cardiac operation in adult patients with congenital heart disease (ACHD). We report recent experience at a large tertiary centre and examine the impact of prosthesis type on outcomes. MethodsAll surgical PVRs performed at our tertiary centre between January 2003 and December 2018 were included. ResultsThe study population included 490 patients (197 women; mean age 29.9 ± 13 years). The types of valves used were Homograft 179 (37%), Perimount 152 (31%), Mosaic 120 (24%), Hancock 31 (6%), and others 5 (1%). Seven (1.4%) early deaths occurred within 30 days after surgery. The survival rates at 1, 5, 10, and 15 years of follow-up were 98.3%, 97.7%, 96.8%, and 95.4%, respectively, whereas freedom from re-intervention was 99.8%, 96.6%, 90.2%, and 81.0%, respectively. During a mean follow-up of 6.5 ± 4.3 years, 27 (5.5%) patients required re-intervention. The type of valve used in these 27 patients during index operation showed no discernible difference in the probability of re-intervention; however, Mosaic valves required earlier re-intervention compared to Perimount valves. ConclusionOur data show no discernible difference in reoperation rates between the different types of prostheses used. On-going surveillance of patients after PVR and further research in developing a life-long prosthesis are clearly warranted.

Total, hemi, or dual-mobility arthroplasty for the treatment of femoral neck fractures in patients with neurological disease : analysis of 9,638 patients from the Swedish Hip Arthroplasty Register.

The aim of this study was to investigate the potentially increased risk of dislocation in patients with neurological disease who sustain a femoral neck fracture, as it is unclear whether they should undergo total hip arthroplasty (THA) or hemiarthroplasty (HA). A secondary aim was to investgate whether dual-mobility components confer a reduced risk of dislocation in these patients. We undertook a longitudinal cohort study linking the Swedish Hip Arthroplasty Register with the National Patient Register, including patients with a neurological disease presenting with a femoral neck fracture and treated with HA, a conventional THA (cTHA) with femoral head size of ≤ 32 mm, or a dual-mobility component THA (DMC-THA) between 2005 and 2014. The dislocation rate at one- and three-year revision, reoperation, and mortality rates were recorded. Cox multivariate regression models were fitted to calculate adjusted hazard ratios (HRs). A total of 9,638 patients with a neurological disease who also underwent unilateral arthroplasty for a femoral neck fracture were included in the study. The one-year dislocation rate was 3.7% after HA, 8.8% after cTHA < 32 mm), 5.9% after cTHA (= 32 mm), and 2.7% after DMC-THA. A higher risk of dislocation was associated with cTHA (< 32 mm) compared with HA (HR 1.90 (95% confidence interval (CI) 1.26 to 2.86); p = 0.002). There was no difference in the risk of dislocation with DMC-THA (HR 0.68 (95% CI 0.26 to 1.84); p = 0.451) or cTHA (= 32 mm) (HR 1.54 (95% CI 0.94 to 2.51); p = 0.083). There were no differences in the rate of reoperation and revision-free survival between the different types of prosthesis and sizes of femoral head. Patients with a neurological disease who sustain a femoral neck fracture have similar rates of dislocation after undergoing HA or DMC-THA. Most patients with a neurological disease are not eligible for THA and should thus undergo HA, whereas those eligible for THA could benefit from a DMC-THA. Cite this article: Bone Joint J2022;104-B(1):134-141.

A Tribological and Ion Released Research of Ti-Materials for Medical Devices.

The increase in longevity worldwide has intensified the use of different types of prostheses for the human body, such as those used in dental work as well as in hip and knee replacements. Currently, Ti-6Al-4V is widely used as a joint implant due to its good mechanical properties and durability. However, studies have revealed that this alloy can release metal ions or particles harmful to human health. The mechanisms are not well understood yet and may involve wear and/or corrosion. Therefore, in this work, commercial pure titanium and a Ti-6Al-4V alloy were investigated before and after being exposed to a simulated biological fluid through tribological tests, surface analysis, and ionic dissolution characterization by ICP-AES. Before exposure, X-ray diffraction and optical microscopy revealed equiaxed α-Ti in both materials and β-Ti in Ti-6Al-4V. Scratch tests exhibited a lower coefficient of friction for Ti-6Al-4V alloy than commercially pure titanium. After exposure, X-ray photoelectron spectroscopy and surface-enhanced Raman spectroscopy results showed an oxide film formed by TiO2, both in commercially pure titanium and in Ti-6Al-4V, and by TiO and Al2O3 associated with the presence of the alloys. Furthermore, inductively coupled plasma atomic emission spectroscopy revealed that aluminum was the main ion released for Ti-6Al-4V, giving negligible values for the other metal ions.

Direct Flow Medical vs. Edwards Sapien 3 Prosthesis: A Propensity Matched Comparison on Intermediate Safety and Mortality.

Aims: To compare intermediate performance and mortality rates in patients, who underwent transcatheter aortic valve implantation (TAVI) with two different types of prostheses: Edwards Sapien 3 (ES3) and Direct Flow Medical (DFM).Methods and Results: 42 consecutive patients implanted with a DFM prosthesis for severe aortic stenosis were matched 1:1 with an equal number of patients, who received an ES3 during the same period. Primary endpoint was mortality. MACE, as a composite of all-cause death, stroke, and re-do-procedure (valve-in-valve), was defined as secondary endpoint. Moreover, we compared NYHA class, NT-proBNP-levels and the extent of restenosis. Patients were followed for 2 years. DFM patients showed echocardiographic elevated mean pressure gradients compared to ES3 patients before discharge (11.2 mmHg ± 5.3 vs. 3.5 mmHg ± 2.7; p < 0.001) and upon 6-months follow-up (20.3 mmHg ± 8.8 vs. 12.3 mmHg ± 4.4; p < 0.001). ES3 candidates showed superior NYHA class at follow-up (p = 0.001). Kaplan-Meier analysis revealed significantly worse survival in patients receiving a DFM prosthesis compared to ES3 (Breslow p = 0.020). MACE occurred more often in DFM patients compared to ES3 (Breslow p = 0.006).Conclusions: Patients receiving DFM valve prostheses showed worse survival and higher rates in MACE compared to ES3. Prosthesis performance regarding mean pressure gradients and patients' NYHA class also favored ES3.

Research progress on finite element analysis of unicompartmental knee arthroplasty in medial knee compartmental osteoarthritis

To review the research progress on finite element analysis (FEA) of unicompartmental knee arthroplasty (UKA) in medial knee compartmental osteoarthritis. The FEA research literature on the medial knee UKA at home and abroad was reviewed, and the progress on the aspects of the influences of the prosthesis arrangement and the postoperative joint line on the mechanical distribution of the knee joint, the improvement of the UKA prosthesis, and the related research of different types of prostheses were summarized. At present, scholars have conducted a large number of FEA studies on UKA in the medial knee compartmental osteoarthritis. The results of the study show that the recommended coronal alignment and the tibial slope angle of tibial component in medial fixed-bearing UKA are 0° and 5°-7°, respectively; and the coronal alignment and the tibial slope angle of tibial component in mobile-bearing UKA are 4° varus to 4° valgus and 5°-7°, respectively. The femoral component is arranged in the neutral position of the distal femur. The joint line is recommended to be the primary alignment. The anatomical UKA prosthesis can restore the biomechanical properties of the normal knee joint. FEA research can clarify the best arrangement and joint line of the medial knee UKA prosthesis based on the mechanical distribution results, and guide the design of UKA prostheses that are more suitable for patients.

Comparison of Aortic Gradient and Ventricular Mass after Valve Replacement for Aortic Stenosis with Rapid Deployment, Sutureless, and Conventional Bioprostheses

Background: The use of rapid deployment and sutureless aortic prostheses is increasing. Previous reports have shown promising results on haemodynamic performance and mortality rates. However, the impact of these bioprostheses on left ventricular mass (LVM) regression remains unknown. We decided to study the changes in remodelling and LVM regression in isolated severe aortic stenosis treated with conventional or Perceval® or Intuity® valves. Method and Results: From January 2011 to January 2016, 324 bioprostheses were implanted in our centre. The collected characteristics were divided into 3 groups: conventional valves, Perceval®, and Intuity®, and they were analysed after 12 months. There were 183 conventional valves (56%), 72 Perceval® (22%), and 69 Intuity® (21.2%). The statistical analysis showed significant differences in transprosthetic postoperative peak gradient (23 [18–29] mm Hg vs. 21 [16–29] mm Hg and 18 [14–24] mm Hg, p < 0.001), ventricular mass electrical criteria regression (Sokolow and Cornell products), and 1-year survival (90 vs. 93% and 97%, log rank p value = 0.04) in conventional, Perceval®, and Intuity® groups. Conclusions: We observed differences in haemodynamic, electrocardiographic, and echocardiographic parameters related to the different types of prosthesis. Patients with the Intuity® prosthesis had the highest reduction in peak aortic gradient and the higher ventricular mass regression. Besides, patients with the Intuity® prosthesis had less risk of mortality during follow-up than the other two groups. Further studies are needed to confirm these findings.

Comparative study between Teflon and Robinson stainless steel Prostheses in ototsclerosis surgery

BACKGROUND: The main cause of conductive hearing loss in the presence of a completely normal tympanic membrane is otosclerosis. There are different types of prostheses that could be used in the operation with different materials, designs, and shapes. The prostheses utilized in this study including both Teflon and Robinson are assessed. The aim of our work is to match and determine the surgical steps, postoperative results, and surgical complications of both Teflon piston and Robinson titanium prosthesis in line with the improvement in hearing and therefore the ability to decrease the air-bone gap.Results: stapedotomy done for 40 patients with Teflon piston and Robinson stainless steel piston prosthesis, 20 patients for each type. Both groups were matched based on age and preoperative bone-conduction scores. Follow up for all patients were done up to 6 months postoperatively. We have excluded all revision cases. A comparison between both prostheses was assessed by differences in the Air Bone (AB) Gap and surgical difficulties and complications. Both groups showed no significant difference either in hearing improvement or postoperative decrease of an air-bone gap. The Robison titanium piston needs more surgical skills than Teflon one. Both groups had no surgical complications.Conclusions: There is an equal benefit to patients with the use either of Teflon piston or Robinson protheses and there is no statistically significant difference between both of them. We need a long time of follow up the results to be analyzed.Keywords: Teflon prosthesis, Robinson prostheses, otosclerosis, stapedectomy.

Retrospective Analysis of Immediate Implants: A Prism with a Different Dimension.

Any tooth loss can be addressed for rehabilitation by different types of prosthesis. But, for certain conditions patients and dentists expect immediate results. An immediate implant falls into such a category: The implant is placed immediately into the extracted socket with the expectation of a quick fix. The present study was designed to retrospectively analyze the factors or choices that lead to immediate implant placement, prevailing conditions during the implant surgical phase, and conditions in the implant prosthetic phase. The study indicates fractured teeth as the most chosen case for immediate implant placement, with more than 1 mm of jump space present between implant and bone socket invariably requiring bone grafting. The study also indicates a survival rate during stage 2 recovery as 16% less than what is reported in the literature.

Distal Radioulnar oint Prosthesis.

The distal radioulnar joint (DRUJ) prostheses have been available for many years and despite their superior outcomes compared to conventional DRUJ reconstructions in both short and long-term follow-ups, they have not become as popular as common hip and knee prostheses. In the current review article, at the first step, we discussed the applied anatomy and biomechanics of the DRUJ, and secondly, we classified DRUJ prostheses according to available literature, and reviewed different types of prostheses with their outcomes. Finally we proposed simple guidelines to help the surgeon to choose the appropriate DRUJ prosthesis.

Different Interventions for Rehabilitation of the Edentulous Maxilla with Implant-Supported Prostheses: An Overview of Systematic Reviews.

To synthesize evidence derived from systematic reviews (SRs) on different interventions for rehabilitation of the edentulous maxilla with implant-supported restorations. A protocol-oriented search was established to address the PICO question: What is the current evidence regarding rehabilitation of the edentulous maxilla with different implant-supported prostheses in terms of implant and prosthesis survival? The primary outcomes were implant and prosthesis survival rates evaluated from SRs of clinical studies including adult patients with complete edentulism of the maxilla and comparing different implant-supported rehabilitation strategies. Methodologic quality of the SRs was assessed with the AMSTAR-2 tool. The final selection process led to the inclusion of 36 SRs that were grouped as: (1) addressing maxillae with sufficient bone to place implants; (2) addressing maxillae with insufficient bone to place implants; and (3) comparing different types of prosthesis, number of implants, patient-reported outcomes, and economic evaluations. The literature describes four or more implants as suitable for full-arch fixed prostheses and implant-supported overdentures; in both cases, the overall survival rate is > 95%. Mini-implants present very high short-term failure rates (> 30%). Poor description of technical complications, adjustments, and maintenance and corresponding costs precluded a cost-effectiveness analysis. No implant-supported rehabilitation of the edentulous maxilla (fixed or removable) should be supported on fewer than four implants. A one-piece full-arch fixed dental prosthesis can be supported by a minimum of two anterior axial plus two posterior distally tilted implants or by six to eight axial implants symmetrically distributed through the posterior and anterior regions of the arch. Four to six implants is the advised number to support an overdenture. The use of mini-implants in the maxilla is inadvisable.

Success of fixed partial denture prostheses observed in a military dental centre: A cross-sectional study

BackgroundFixed dental prostheses have been provided in the Armed Forces for a long time, yet definite evidence-based guidelines on the success and failure of different types of prostheses are currently lacking. A cross-sectional observational study was conducted as a step towards addressing this lacuna. MethodsThe study included 156 patients and 538 prostheses based on pre-established inclusion criteria. The types of prostheses that were evaluated included crowns, fixed partial dentures (FPDs), post and core restorations, dental implants and veneers. Visual, tactile and radiographic examination was used for evaluating the prostheses. Success, survival and failure of prostheses were evaluated, and the types of complications leading to the failure were also recorded. In addition, the oral hygiene status of the included patients was also evaluated using the Oral Hygiene Index-Simplified. ResultsThe overall failure rate in all prostheses combined together was 28.81%. The failure rate in cantilever FPDs was the highest at 44.44%. It was 16.67% in veneers, 35.37% in conventional FPDs, 23.81% in single crowns and 30.56% in all post and core restorations. ConclusionBarring the all-ceramic prostheses and fibre post and core restorations, the rate of occurrence of both complications and failures in the remaining categories of prostheses was higher than that mentioned in the literature.