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OBJECTIVES: To compare the interfacial fracture toughness (IFT) with or without aging, of four different classes of CAD-CAM ceramic and composite materials bonded with self-adhesive resin cement to titanium alloy characteristic of implant abutments. METHODS: High translucent zirconia (Katana; KAT), lithium disilicate-based glass-ceramic (IPS. emax.CAD; EMX), polymer-infiltrated ceramic network material (PICN) (Vita Enamic; ENA), and dispersed filler composite (Cerasmart 270; CER) were cut into equilateral triangular prisms and bonded to titanium prisms with identical dimensions using Panavia SA Cement Universal. The surfaces were pretreated following the manufacturers' recommendations and developed interfacial area ratio (Sdr) of the pretreated surfaces was measured. IFT was determined using the Notchless Triangular Prism test in a water bath at 36 °C before and after thermocycling (10,000 cycles) (n = 40 samples/material). RESULTS: IFT of the materials ranged from 0.80 ± 0.25 to 1.10 ± 0.21 MPa.m1/2 before thermocycling and from 0.71 ± 0.24 to 1.02 ± 0.25 MPa.m1/2 after thermocycling. There was a statistical difference between IFT of CER and the two top performers in each scenario: KAT and EMX before aging, and KAT and ENA after aging. Thermocycling significantly decreased IFT of EMX. The Weibull modulus of IFT was similar for all materials and remained so after thermocycling. Sdr measurements revealed that ENA (7.60)>Ti (4.97)>CER (2.85)>KAT (1.09)=EMX (0.96). SIGNIFICANCE: Dispersed filler CAD-CAM composite showed lower performance than the other materials. Aging only affected IFT of Li-Si glass-ceramic, whereas zirconia and PICN performed equally well, probably due to their chemical bonding potential and surface roughness respectively.

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BACKGROUND: The aim of this case study is to present the rationality and scientific evidence of a new design for a double (DA) and triple (TA) dental abutment-implant with their specific new concept of biodynamic optimized peri-implant tissue (BOPiT). METHODS: The innovative design of these abutments with a paraboloid geometry was based on BOPiT, simultaneously involving the principles of mechanobiology, biotensegrity, and mechanotransduction. Thus, 37 consecutive individuals/43 cases rehabilitated with single dental implant using the innovative DA (n = 28) and TA (n = 15) on 43 implants were included in this case study. The DA and TA support 2 or 3 dental crowns on a single implant, respectively. Clinic and radiographic examinations were presented at T1 (loading after 4 months) and T2 [final examination with an average follow-up time of 7.2 years (>3 to 12 years)]. RESULTS: At T2, mean scores for plaque index, peri-implant bleeding on probing, and peri-implant probing depth were low, depicting healthy peri-implant conditions. All radiographic images showed insignificant annual marginal bone loss (0.022 ± 0.05 mm) when compared to T1, reflecting great bone stability. CONCLUSION: DA and TA, based on the BOPiT concept, represent an advantageous, simple and non-invasive mechanism for the longevity and healthy regulation of the peri-implant tissues.

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With the rapid development of implant techniques and digital technology, digital impressions have become a commonly used impression method in implant restoration. At present, the accuracy of intraoral digital impressions directly applied to implant-supported full-arch prostheses remains inadequate, which is due to the high accuracy requirement of full-arch implant impressions, while there are still technical challenges in intraoral digital impressions about recognition and stitching. In this regard, scholars have proposed a variety of scanning strategies to improve the accuracy of intraoral scan, including mucosal modifications, auxiliary devices and novel scan bodies. At the same time photogrammetry, as a new digital impression technique, has been developing steadily and exhibits promising accuracy. This article reviews the research progress on the accuracy of edentulous full-arch implant impressions and techniques which can improve the accuracy of intraoral digital impressions, to provide reference for clinical application.

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Implant prostheses and other fixed and removable metal prostheses have led to an increase in demand for the development of new and efficient materials such as high-performance polymers polyetheretherketone (PEEK) over titanium and other metals because of their further complications in the human body. PEEK is a polymer that is nontoxic and has a modulus of elasticity that is comparable to that of human bone. PEEK implants provide benefits over metal implants, such as reducing the stress shielding effect, simple processing, and color resemblance to natural teeth. And it is a fantastic alternative to titanium for dental and orthopedic implants. The current review is undertaken to understand the properties of this PEEK material to weigh its benefits and drawbacks for potential use in dental implants and other prostheses.

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BACKGROUND: There is limited evidence available regarding patient satisfaction and quality of life assessment in patients with extraoral maxillofacial prostheses. OBJECTIVES: This systematic review aims to understand the impact of extraoral implant retained prosthesis in improving the quality of life in patients with extraoral maxillofacial defects/abnormalities. METHODS: A comprehensive search was performed of nine electronic databases up to August 2022, which yielded three articles that satisfied the inclusion criteria. The study characteristics and findings were extracted, and the included studies were assessed for quality. RESULTS: Three cohort studies were selected. Despite the lack of uniformity in the quality of life instruments, there was a general trend in improvement in the quality of life for patients with implant retained extraoral prostheses. The studies were also deemed to be of high quality on assessment. CONCLUSION: Given the limitations of this systematic review, there exists limited evidence indicating that implant prostheses may enhance the quality of life for individuals with extraoral maxillofacial defects or abnormalities.

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BACKGROUND: There is limited evidence available regarding patient satisfaction and quality of life assessment in patients with intraoral maxillofacial defects managed with maxillofacial prostheses. OBJECTIVES: This systematic review aims to understand the impact of intraoral implant prostheses in improving the quality of life in patients with intraoral maxillofacial defects/abnormalities. METHODS: A comprehensive search was performed of nine electronic databases from January 1970 to August 2022. Hand searching of the reference lists of the included papers and of relevant journal publications between 2012 and 2022 was also undertaken. Key information was extracted from included studies alongside quality and risk of bias assessments. RESULTS: The systematic review encompassed a total of seven studies, comprising five retrospective and two prospective investigations, with one of the prospective studies being a randomised clinical trial. The evaluation of the risk of bias and quality assessment revealed heterogeneity in the results, preventing meaningful comparisons among the included studies. CONCLUSION: Within the limitation of the systematic review, there is limited evidence to suggest that implant prostheses improve the quality of life in patients with intraoral maxillofacial defects or abnormalities.

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PURPOSE: To assess the effect of different scan patterns on the fit of implant-supported complete-arch prototype prostheses fabricated via a complete digital extraoral protocol with a reverse scan body. MATERIALS AND METHODS: A mandibular cast with four multi-unit abutment (MUA) implant analogs with adequate antero-posterior spread served as the reference cast, simulating a common clinical patient situation, and a polymethylmethacrylate interim screw-retained prosthesis was fabricated on it. Novel reverse scan bodies were connected to the interim prosthesis on the intaglio of the MUA abutments and extraoral scanning was performed with a white light intraoral scanner (TRIOS 4; 3 shape) and three different scan patterns: starting from the occlusal surface of the interim prosthesis (O-group), starting from the intaglio (I-group), and helix pattern (H-group).  The resulting STL files from the three groups were then imported to computer-aided design (CAD) software and after the digital design, the STL files were exported to a computer-aided manufacturing (CAM) milling machine which generated a total of 15 CAD-CAM milled prototype prostheses per group. Two clinicians assessed the fit of each digitally fabricated prototype prosthesis on the reference cast, utilizing the screw-resistance test and radiographic evaluation. Fisher's exact test was used to test the difference between the three groups, and Cohen's k-score was used to assess the inter-examiner agreement. RESULTS: Out of the three different groups, the O-group scan pattern led to 100% prosthesis fit, while the prototype prostheses generated from I- and H-groups had 80% and 53% fit, respectively. The results were statistically significant (p = 0.008). CONCLUSIONS: Occlusal scan pattern leads to fitting milled prototype prostheses after extraoral scanning with reverse scan bodies without intraoral implant data acquisition.

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Oral reconstruction in fully edentulous patients can be challenging at times. Hence, it is important to offer the most suitable treatment option after a detailed clinical examination and treatment plan. This 14-year long-term follow-up report is the clinical case of a 71-year-old nonsmoker who visited the clinic in 2006 and opted for full-mouth reconstruction using Auro Galvano crown (AGC) attachments. Maintenance was performed twice a year for the past 14 years, and the clinical results were satisfactory, with no signs of inflammation or lack of retention of the superstructures. This was associated with a high level of patient satisfaction, as indicated by the Oral Health Impact Profile. Compared to the screw-retained implants over dentures, AGC attachments can be a viable and effective treatment option when restoring fully edentulous arches.

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OBJECTIVES: To provide an overview about the current approaches to prevent peri-implant diseases in edentulous patients with complete-arch implant-supported prostheses, and to review the clinical applications of the latest digital technologies for implant prosthodontics. METHODS: A review of the guidelines to prevent peri-implant diseases in patient's receiving complete-arch implant-supported prostheses including facially driven treatment planning procedures using either conventional or digital methods, computer-aided implant planning procedures, and prosthodontic design variables including the optimal number and distribution of dental implants, implant to abutment connection type, implant or abutment level design, screw- or cement-retained alternatives, prostheses contours, and material selection is provided. Furthermore, an outline of the current therapeutic management approaches to address peri-implant diseases is reviewed. CONCLUSIONS: Clinicians should understand and know different planning and design-related variables that can affect biological and mechanical complication rates of complete-arch implant-supported prostheses. Maintenance protocols are fundamental for minimizing biological and mechanical complications.

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Implant dental therapy is a clinical procedure used for treating patients with tooth loss with known clinical success. This clinical study aimed to evaluate the long-term clinical outcomes of dental implants in partially and totally edentulous patients. A total of 544 Microdent (Microdent SU, Implant Microdent System®, Santa Eulàlia de Ronçana Barcelona, Spain) screw implants were placed in 111 patients using a two-stage surgical technique and a conventional loading protocol (lasting 3 months). Implant and prosthetic clinical findings were evaluated during a 15-year follow-up. A total of 6 implants were lost during the healing period, and 124 prostheses were placed over the 538 implants that remained: 20 single crowns, 52 partially fixed bridges, 45 full-arch fixed restorations, and 7 overdentures. A total of 20 of these were lost during the follow-up period. The cumulative survival rate for all implants was 96.4%. The data underwent statistical analysis (significance level: p < 0.05). The mean marginal bone loss was 1.82 ± 0.54 mm, ranging from 1.2 to 3.1 mm. The most frequent complications were mechanical prosthodontic complications (16.2%). In all, 11.8% of implants showed periimplantitis as the primary biological complication. Dental implants inserted in both the maxillary and mandibular areas produce long-term favorable outcomes and stable tissue conditions when a delayed loading protocol is followed.

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Type II dentinogenesis imperfecta is an autosomal dominant condition that affects dentin which increases the complexity of the predictability of restorative treatment. Computer-aided design and computer-aided manufacturing (CAD-CAM) technologies permit the creation of highly accurate devices and dental prostheses that simplify the planning and execution of advanced implant surgery and full-mouth rehabilitation. This clinical report presents the interdisciplinary management of a 20-year-old male with dentinogenesis imperfecta type II. In this article, a combination of analog and CAD-CAM technologies were used to fabricate devices that aided planning, assisted intermaxillary fixation and implant placement, served as interim prostheses, and permitted the accurate establishment of esthetics and occlusion of the definitive full-arch prostheses.

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Polyetheretherketone (PEEK) has become a useful polymeric biomaterial due to its superior properties and has been increasingly used in dentistry, especially in prosthetic dentistry and dental implantology. Promising applications of PEEK in dentistry are dental implants, temporary abutment, implant-supported provisional crowns, fixed prosthesis, removable denture framework, and finger prosthesis. PEEK as a long-term provisional implant restoration has not been studied much. Hence, this review article aims to review PEEK as a long-term provisional implant restoration for applications focusing on implant dentistry. Articles published in English on PEEK biomaterial for long-term provisional implant restoration were searched in Google Scholar, ScienceDirect, PubMed/MEDLINE, and Scopus. Then, relevant articles were selected and included in this literature review. PEEK presents suitable properties for various implant components in implant dentistry, including temporary and long-term provisional restorations. The modifications of PEEK result in wider applications in clinical dentistry. The PEEK reinforced by 30-50% carbon fibers can be a suitable material for the various implant components in dentistry.

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PURPOSE: The purpose of this in vitro study was to evaluate the effect of ambient light illuminance on the accuracy and scanning time of different intraoral scanners (IOSs) in complete-arch implant scans. MATERIAL AND METHODS: Seven IOSs (TRIOS 3, Primescan, Element 5D, i700, i500, CS3700, and CS3600) at 5 ambient lighting illuminances (100, 500, 1000, 5000, and 10 000 lux) were evaluated. An edentulous cast with 4 implants was selected as the master model. An implant scan body was tightened on each implant. The cast was digitized by using a laboratory scanner to obtain a reference standard tessellation language (STL) file, and 50 scans (10 per ambient light condition) were recorded with each IOS. Scanning time was recorded by using a digital chronograph. Intraoral scan deviations were calculated by using a 3D metrology software program (Geomagic Control X). Kruskal-Wallis and pairwise comparison tests were used to analyze the data (α=0.05). RESULTS: The trueness and precision values obtained for each IOS tested were significantly different under the varying lighting conditions assessed. TRIOS 3 (34.0 ± 3.3 µm trueness; 24.5 ± 14.9 µm precision), Element 5D (34.5 ± 7.1 µm trueness; 25.9 ± 7.6 µm precision), and CS3700 (34.9. ±13.0 µm trueness; 34.6 ± 19.2 µm precision) performed better under 100 lux illumination, CS3600 (69.5 ± 24.0 µm trueness; 36.6 ± 20.1 µm precision) at 500 lux; i500 (36.2 ± 5.1 µm trueness; 21.4 ± 6.8 µm precision) at 1000 lux; i700 (34.8 ± 2.2 µm trueness; 15.4 ± 5.0 µm precision) at 5000 lux, and Primescan (37.4 ± 37.3 µm trueness; 26.2 ± 26.2 µm precision) at 10,000 lux. Additionally, the scanning time was different under different illuminance for each IOS. The fastest IOS in all light conditions was Primescan, with significant differences with all the groups (P<.01), followed by TRIOS 3 in all groups except under 100 lux illumination, where i700 was the second fastest. CONCLUSIONS: Ambient light influenced the accuracy and scanning time of IOSs assessed; however, the effect was not the same for all devices. It is necessary to optimize ambient light illuminance for each IOS to maximize scanning accuracy.

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PURPOSE: To evaluate the relationship between different dimensional parameters in implant-supported monolithic zirconia fixed complete dental prostheses (IFCDPs) and the incidence of framework fracture in a large sample of cases in vivo. MATERIALS AND METHODS: This retrospective observational study evaluated all patients rehabilitated with screw-retained zirconia IFCDPs between January 2013 and April 2019 at a private practice. The minimum follow-up period was 1 year after occlusal loading. Fractures were classified as: type I-fractures that happened between but not involving the two most posterior screw-access openings (SAOs) and type II-fractures of the distal cantilever. Cantilever length, distal connector cross-sectional area, and screw access opening length were measured using data obtained from digital scans. Logistic regression was performed to evaluate the relationship between types I and II fractures and the independent variables (dimensional parameters). Using the receiver operating characteristic curves, two parameters were identified to be useful for establishing a cut-off and predicting type II fractures. RESULTS: A total of 180 prostheses delivered to 140 patients were analyzed. Five implants failed in three patients: three before delivery of the definitive prostheses and two after. Ten prostheses failed (5.6% prosthetic failure rate): 2 because of implant failures, and 8 because of framework fractures. Five fractures were classified as type I and three as type II. Significant associations were found between cantilever length and type I fractures (Wald = 5.772, df = 1, p = 0.016), distal connector cross-sectional area and type II fractures (Wald = 3.806, df = 1, p = 0.051), and cantilever length and the total number of fractures (Wald = 6.117, df = 1, p = 0.013). CONCLUSION: Zirconia IFCDPs may be reliable medium-term solutions if some dimensional parameters are followed. The ratios between the cantilever length and cross-sectional connector area should be <0.51, while the ratio between the cantilever length and screw access opening length should be <1.48.

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OBJECTIVES: This research aimed to compare the oral health-related quality of life (OHRQoL) between fully dentate subjects and edentulous patients wearing implant-supported fixed partial dentures (i-FPDs). The clinical conditions of both types of restorations were evaluated. METHODS: Participants were assigned to: Group-1 (SR, n = 50): screw-retained i-FPD wearers; Group-2 (CR, n = 50): cement-retained i-FPD wearers; and Group-3 (ND, n = 50): dentate subjects with a healthy natural dentition (controls). Patients answered the OHIP-14sp and QoLIP-10 questionnaires. Data related to sociodemographics, prosthesis features, peri­implant status, complications, and subjective evaluations, were compiled. Potential modulators of the OHRQoL and the i-FPDs' clinical conditions were assessed using non-parametric tests (α= 0.05). RESULTS: ND individuals were the least satisfied (OHIP-14sp; p< 0.001). Both prosthodontic groups reported similar levels of wellbeing, excluding the speaking difficulties, which were lower for SR wearers as shown by both scales (p = 0.001). The most discontented patients (OHIP-14sp) were: women (p = 0.022), under 65 years (p = 0.03), without partner (p< 0.001) and having a crown (p = 0.033). The level of education/schooling also affected the OHIP-14sp scores (p< 0.001). Implant mobility and peri­implantitis were more frequent among CR wearers (p-values= 0.008 and 0.05, respectively). CONCLUSIONS: The OHRQoL of both prosthodontic groups was comparably higher than that of the dentate subjects, who were the most nonconformist. The self-perceived satisfaction was mainly modulated by sociodemographic factors. CLINICAL SIGNIFICANCE: Overall, the retention system did not impact the OHRQoL, prosthetic problems, and subjective evaluations of i-FPD wearers. However, the cementation may increase the risk of peri­implant diseases.

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OBJECTIVES: This observational cross-sectional study aimed to evaluate and compare the oral health-related quality of life (OHRQoL) and clinical performance between dentate subjects and edentulous patients restored with conventional dentures or implant overdentures. METHODS: 85 edentulous patients were grouped as follows: Group-1 (CD): conventional denture wearers (n = 42), and Group-2 (IO): implant-retained overdenture wearers (n = 43). For the OHRQoL comparisons, a control group of subjects with a healthy natural dentition (Group-3, ND; n = 50) was included. Participants completed three validated questionnaires (OHIP-14sp, OHIP-20sp, and QoLIP-10). Socio-demographic data, prosthesis-related factors, clinical condition of the mouth, and patient subjective evaluations, were gathered. Descriptive and non-parametric probes were run (α = 0.05). RESULTS: The ND group was the most unsatisfied (OHIP-14sp; p ≤ 0.001). The OHIP-20sp attributed significantly worse Psychological disability (p = 0.029) and Handicap (p = 0.027) to CD wearers when compared to IO wearers. The CD group showed the significantly highest need for relining (p = 0.041), and the lowest retention (p = 0.011). The OHIP-14sp disclosed a significantly worse OHRQoL for those volunteers who had a job (p = 0.003), a basic education instead of a secondary one (p = 0.022), and no partner (p = 0.006). CONCLUSIONS: The overall OHRQoL was comparable for both prosthodontic groups, being modulated by socio-demographic and prosthesis-related features. Nonetheless, CD wearers presented prosthetic complications more frequently. CLINICAL SIGNIFICANCE: While dentate subjects were the most critical about their oral condition and its repercussion in their life, implant overdenture wearers tended to observe a better OHRQoL and clinical performance compared to conventional denture wearers.

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AIM: The aim of this study is to evaluate and compare the accuracy of master casts obtained by different splinting techniques for implant level impressions in All-on-Four implant treatment protocol using a coordinate measuring machine. SETTINGS AND DESIGN: The study design involves an in vitro study. MATERIALS AND METHODS: In this in vitro study, a reference clear acrylic resin (AR) model comprising four regular platform implant 3.6 mm × 10.0 mm (Dentium Implant India Pvt. Ltd, Bengaluru, India) which was placed following the All-on-Four implant protocol is prepared. Impressions were categorized into three different groups: Group 1 - impression copings were nonsplinted; Group 2 - impression copings were splinted using AR sectioned 17 min after setting and rewelded with the same resin; and Group 3 - impression copings were splinted by titanium bar using an intraoral welder. A total of 33 (n = 11 in each group) impressions were made to evaluate three different splinting techniques. Impressions were poured with Type 4 dental stone. A coordinate measuring machine was used to record the x, y, and z co-ordinates and angular displacement. The measurements were compared with those obtained from the reference model. STATISTICAL ANALYSIS USED: One-way ANOVA test was used as a test of significance. RESULTS: There was less linear and rotational displacement for the metal-splinted group (P < 0.001) In the x-axis, nonsplinted group showed a statistically significant difference in straight implants (2 and 3 implants) (P = 0.001) of All-on-Four treatment protocol. CONCLUSION: The splinting methods have a direct effect on the accuracy of definitive casts. The metal-splinted direct technique produced the most accurate casts followed by AR-splinted direct technique and nonsplinted direct technique.

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PURPOSE: To report the rate of technical complications and prosthesis survival in a cohort of edentulous patients treated with implant-supported fixed complete dental prostheses (IFCDPs) after a mean observation period of at least 1 year. MATERIALS AND METHODS: The single-visit examination included clinical and radiographic assessment, occlusal analysis, photographs and questionnaire assessing patient satisfaction in a cohort of 52 patients rehabilitated with 71 IFCDPs (supported by 457 implants). The IFCDPs were assessed for technical complications, number of implants and cantilever extension, retention type and prosthetic material type. Comparison was made between ceramic IFCDPs (Group 1) and metal-resin IFCDPs (Group 2). Kaplan-Meier survival curve analysis was carried out for assessment of prosthesis survival and was done for both Groups 1 and 2 separately. The Cox proportional hazard model was used for survival analysis, adjusting for a number of potential confounders, to evaluate the association between prosthesis survival and several risk factors such as type of opposing occlusion, nightguard use, and presence of bruxism. Responses to patient satisfaction questions were compared with Fisher's exact test. RESULTS: Out of 71 edentulous arches (52 patients) restored with IFCDPs, 6 IFCDPs had failed, yielding a cumulative prosthesis survival rate of 91.6 % after a mean observation period of 5.2 years (range: 1-12 years) after definitive prosthesis insertion. Three IFCDPs were lost due to implant failures after 5.8 to 11 years of functional loading. Additionally, 3 metal-resin IFCDPs failed due to technical complications. Minor complications were the most frequent complications observed, namely wear of the prosthetic material (9.8% annual rate) being the most common, followed by decementation of cement-retained IFCDPs (2.9%), and loss of the screw access filing material of the screw-retained IFCDPs (2.7%). The most frequently observed major complication was fracture of the prosthetic material (1.9% annual rate), followed by fracture of occlusal screw (0.3%), and fracture of framework (0.3%). The annual rate of wear of prosthetic material was 7.3% for porcelain IFCDPs (n = 19/55) and 19.4% for metal-resin IFCDPs (n = 13/16), yielding a statistically significant difference between the 2 groups (p = 0.01). CONCLUSIONS: After a mean exposure time of 5.2 years, 91.6% prosthesis survival rates were achieved (65 out of 71 IFCDPs). The most frequent minor technical complication was wear of the prosthetic material with estimated 5-year rate of 49.0%, while the most frequent major complication was fracture of the prosthetic material with estimated 5-year dental unit-based rate of 9.5%. The cumulative rates for "prosthesis free of minor complications" at 5- and 10-years were 60.5% (95% CI: 47.2-71.3%) and 8.9% (95% CI: 2.9-18.0%), respectively. The cumulative rates for "prosthesis free of major technical complications" at 5- and 10-years were 85.5% (95% CI: 73.0-92.5%) and 30.1% (95% CI: 12.0-50.6%), respectively. Presence of bruxism, and absence of a nightguard were associated with increased risk for chipping of the prosthetic material of the IFCDPs.

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PURPOSE: Modal analysis has been used to monitor and quantify the vibration of each component of a prosthesis at its natural frequency. An understanding of the vibrational characteristics of a prosthesis can guide selection of the appropriate prosthesis configuration to prevent excessive stress. In this study, modal analysis of fixed implant-supported prostheses with 4 or 6 abutments in edentulous maxillae was performed. METHODS: Sixteen patients underwent maxillary dental implant treatment and received screw-fixed implant-supported prostheses (9 patients received 4-abutment prostheses and 7 patients received 6-abutment prostheses) in edentulous maxillae. An impact hammer was used for excitation of the prostheses, and vibration was detected on every crown of the prostheses. The modal parameters were determined in each subject. Furthermore, the modal shapes were compared at each natural frequency. RESULTS: The median natural frequencies of subjects with 4- and 6-abutment prostheses were 697 and 781Hz, respectively. The mean damping ratios did not differ significantly between 4- (8.2±1.7%) and 6-abutment (6.6±1.7%) prostheses (p=0.125). The mean maximum displacements of fixed prostheses were significantly lower for 6-abutment (10.3±3.3µm) than for 4- (20.3±9.1µm) prostheses (p=0.004). The median number of vectors in antiphase was significantly lower for 6- (4) than for 4-abutment prostheses (14) (p=0.001). CONCLUSIONS: The current study demonstrated less adverse vibration in the 6-abutment prostheses than in the 4-abutment prostheses, suggesting that modal analysis can contribute to novel future developments in the designs of dental implant prostheses.

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PURPOSE: To retrospectively assess complications and clinical and radiographic outcomes of edentulous patients treated with double full-arch implant-supported fixed complete dental prostheses (IFCDPs) after a mean observation period of 5.1 years. MATERIALS AND METHODS: The single-visit clinical and radiographic examination included medical and dental history review and clinical assessment of biologic and technical complications encountered with all implants and IFCDPs. Life table analysis and Kaplan-Meier survival curves were calculated. Analysis was conducted to evaluate the association between prosthesis survival and several risk factors such as type of opposing occlusion, nightguard use, and presence of bruxism. RESULTS: Nineteen edentulous patients restored with 38 IFCDPs were included. A total of 249 implants were placed and 2 implants failed after a mean observation period of 5.1 years (range: 1-12 years), yielding an overall implant survival rate of 99.2% and prosthesis survival rate of 92.1%. Three out of 38 IFCDPs were lost, 1 after implant losses and 2 due to technical complications. The most frequent minor biologic complication was soft tissue recession with an estimated 5-year rate of 45.5% (95% CI: 39.4-57.5), while the most frequent major complication was peri-implantitis with an estimated 5-year implant-based rate of 9.5% (95% CI: 6.7-11.3). The most frequent minor technical complication was wear of the prosthetic material with an estimated 5-year rate of 49.0% (95% CI: 37.4-76.4), while the most frequent major technical complication was fracture of the prosthetic material with an estimated 5-year dental unit-based rate of 8.0% (95% CI: 6.6-10.1). CONCLUSIONS: After a mean use time of 5.1 years, high implant and prosthesis survival rates were observed. The most frequent major biologic complication was peri-implantitis, and the most frequent major technical complication was fracture of the prosthetic material. The 5-year estimated cumulative rates for "prosthesis free of biologic complications" was 50.7% (95% CI: 33.7-65.4) and for "prosthesis free of technical complications" was 57.1% (95% CI: 39.3-71.5).

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