Implant-supported Fixed Partial Dentures Research Articles

Effect of Prosthetic Material and Support Type on Stress Distribution of Fixed Partial Dentures: A Finite Element Study

Choosing an appropriate prosthetic material for the superstructure of an implant-supported or tooth-implant supported fixed partial denture (FPD) is crucial for the success of the prostheses. The objective of this study was to examine the effect of prosthetic material type and tooth-to-implant support on stress distribution of FPDs using three-dimensional finite element analysis (3D FEA). Two FEA models were generated, distinguished by their support configurations: Model I representing an FPD supported by implants, and Model II depicting an FPD supported by both a tooth and an implant. Two different restorative materials, porcelain-fused-to-metal (PFM) and monolithic zirconia, were evaluated for stress distribution under axial and oblique loads of 300 N applied to the pontic. Under both axial and oblique loading conditions, the maximum von Mises stress values were observed to be higher in the implant-abutment complex of both zirconia implant-supported and tooth-implant-supported FPDs compared to PFM FPDs. In the case of axial loading, comparable stress values were found in the cortical bone for PFM (12.65 MPa) and zirconia implant-supported FPDs (12.71 MPa). The zirconia tooth-implant-supported FPD exhibited the highest stress values in the implant-abutment system.

Clinical Evaluation of Two Distinct Materials for Implant-Supported Interim Fixed Partial Prostheses: An Original Research

ABSTRACT Aim: This study aimed to evaluate the clinical efficacy of posterior resin implant-supported fixed partial dentures (FPDs) made from two different computer-aided design and computer-aided manufacturing (CAD–CAM) materials: polymethylmethacrylate (PMMA) and polyoxymethylene (POM). Materials and Methods: Twenty-one patients received a total of 49 interim implant-supported FPDs. The same participant received PMMA and POM as part of the control and experimental groups, respectively. The restorations were evaluated 1 week, 3 months, and 6 months after placement. In addition, their functional wear and color stability were assessed. Nonparametric statistics (α = 0.05) were used to analyze the data. Results: The study found that PMMA outperformed POM in surface and color parameters, with more fractures occurring with internal conical connection implants. The color stability analysis showed ΔE*ab values of 7.18 for PMMA and 8.8 for POM, with no significant differences. After 6 months of operation, both materials showed a significant increase in wear, but no significant differences were found within the materials. Conclusion: The study found that PMMA interim implant-supported FPDs outperformed POM in surface and color parameters, while polymer posterior implant-supported FPDs with internal conical connection implants were more fracture-prone.

Influence of a mesial cantilever on stress, strain, and axial force in fixed partial dentures with a distally tilted implant in the atrophic posterior maxilla.

This study aimed to investigate whether the presence of a mesial cantilever influences the biomechanical behavior and screw loosening in fixed partial dentures (FPDs) with a distally tilted implant in the atrophic posterior maxilla and where to best place the distal implant. Two configurations of implant-supported four-unit FPDs were modelled using finite element analysis. Five interabutment distances were considered. The stress and strain distributions in the implants, abutments, and prosthetic screws were verified under occlusal loading. The development of the axial force on the abutments and screws was also examined. Two-sample t-tests were used to identify differences (P < 0.05). The von Mises stress distributions of the components in the two configurations were similar, as were the maximum plastic strains of the distal prosthetic screws, distal implants, and 30° abutments. The difference in the maximum plastic strains of the straight abutments was statistically significant. The preload of the 30° abutment screws was significantly reduced after the initial loading. In the absence of a mesial cantilever, the axial force on the straight abutments increased. However, when a mesial cantilever was used, the preload of the straight abutments was maintained, and the axial force on the prosthetic screws fluctuated less. The axial force fluctuation of the abutments gradually decreased as the interabutment distance increased. Mesial cantilever usage had minimal effect on stress or strain distribution in FPD implants, abutments, or prostheses. However, it helped resist screw loosening. The distal screw access hole was preferably positioned close to the prosthetic end.

The Role of Digital Facebow for CAD/CAM Implant-Supported Crowns Workflow.

Recent advancements in digital technologies have transformed clinical workflows in dentistry, ensuring precise restorations. Custom-made crowns and fixed partial dentures (FPDs) now rely on virtual articulation. The digital facebow provides individualized data for CAD settings, streamlining the fabrication via digital workflow. For the purpose of demonstrating the differences observed during fabrication, we present a case report involving a 68-year-old patient seeking a replacement for missing teeth 24, 25, 26, and 27. The treatment plan involved the fabrication of an implant-supported FPD using monolithic zirconia (ZrO2). However, technical hurdles emerged during the planning phase, primarily due to spatial limitations posing a risk of mechanical failure over time. Consequently, we pivoted approach towards a porcelain fused to metal (PFM) FPD. For the PFM FPD, individual values from the digital facebow adjusted both virtual and conventional articulators. For comparison, two ZrO2 FPDs were milled-individual settings and average settings. All restorations underwent assessment for occlusion in maximal intercuspal position and eccentric mandible movements. In conclusion, the case report showed that individualized PFM FPD required minimal adjustments compared to milled ZrO2 restorations, whether using individual or average values. Utilizing individual values from the digital facebow reduced operator working time and minimized the intraoral adjustments.

Association between the treatment choice of implant-supported fixed partial dentures and oral health-related quality of life in patients with a shortened dental arch: A preliminary observational study

Background/purposeIn cases of missing posterior teeth, treatment modalities based on the shortened dental arch (SDA) concept may be a viable alternative. However, the association between oral health-related quality of life (OHRQoL) and patients’ treatment decisions remains unclear. This study aimed to investigate the association between OHRQoL and the decision to be treated with implant-supported fixed partial dentures (IFPDs) or take a wait-and-see approach in patients with an SDA missing a single second molar and to clarify the impact of IFPD treatment on the OHRQoL. Materials and methodsThe Oral Health Impact Profile (OHIP) questionnaire was administered twice (pre- and post-treatment) and once to 41 patients with a unilateral SDA missing a single second molar who chose IFPD treatment (IFPD group, n = 22) and the wait-and-see approach (no treatment group, n = 19), respectively. Logistic regression analysis was performed with IFPD treatment choice as the objective variable and the four OHIP dimension scores, age, and sex as covariates. The pre- and post-treatment values of the OHIP summary and four-dimension scores were compared using a paired t-test. ResultsThe IFPD treatment choice was significantly associated with sex (male), higher Oral Function dimension scores, and lower Psychosocial Impact dimension scores (all P < 0.05). The OHIP summary and four-dimension scores were significantly lower following IFPD treatment (all P < 0.05). ConclusionIFPD treatment for a single missing second molar may be clinically beneficial for improving the OHRQoL of patients with an SDA who experience a decline in masticatory function.

Difference in marginal bone loss around implants between short implant-supported partial fixed prostheses with and without cantilever: a retrospective clinical study

PurposeTo investigate the influence of cantilever prosthetic arm on the marginal bone loss (MBL) over time around dental implants supporting short fixed partial dentures (FPDs), in a record-based retrospective study.MethodsAll cases of 3-unit implant-supported FPDs, supported by 2–3 implants, from the database of cases treated at one specialist clinic were considered for inclusion. Only implants with a minimum of 36 months of radiological follow-up were considered. Univariate linear regression models were used to compare MBL over time between 12 clinical covariates, after which a linear mixed-effects model was built.ResultsOne-hundred-thirty-nine patients (64 men, 75 women) with 164 3-unit implant-supported FPDs (333 implants supporting non-cantilevered FPDs, 94 supporting cantilevered FPDs) were included in the study. The patients were followed up clinically and radiographically for a mean of 154.1 ± 78.0 (min–max, 37.3–364.6) and 132.9 ± 77.3 months (min–max, 36.8–329.9), respectively. The total number of marginal bone level double measurements (mesial and distal sides of each implant) was 2909. FPDs with cantilever presented an estimated greater MBL over time compared to FPDs without cantilever. Bruxism, sex (women), implant (modified) surface, and (poor) bone quality were also associated with higher MBL over time.ConclusionsThe use of a cantilever extension is suggested to negatively affect the bone marginal level over time around implants supporting 3-unit FPDs. Due to the small difference of the estimated MBL over long periods of follow-up between the groups, it is a matter of debate if the observed negative effect may be of clinical significance.Graphical

Intraoral Scan Accuracy and Time Efficiency in Implant-Supported Fixed Partial Dentures: A Systematic Review.

The digital implant impression technique (DIT) and conventional implant impression technique (CIT) workflows in implant-supported fixed partial dentures (FPDs) have not been extensively compared in prior studies. Moreover, there is no agreement on the more accurate method that entails less time in the laboratory and during the clinical phases of fabrication and delivery of the prosthesis, respectively. This review aimed to assess the precision of the imaging procedure and overall fabrication time of the DIT and CIT for the implant-supported FPDs. An electronic search was performed using PubMed, Scopus, EMBASE, Cochrane Oral Health Group, and Dentistry and Oral Science Source databases through EBSCO for relevant studies from January 2014 to April 2023. Following the preliminary screening, the studies that met the inclusion criteria underwent full-text review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The Cochrane Collaboration risk of bias appraisal tool and Newcastle-Ottawa scale were applied to assess the quality of randomized controlled trials (RCTs) and non-randomized prospective clinical studies, respectively. The initial search yielded 332 studies, and after excluding duplicates, 241 papers were available for screening. Titles and abstracts were reviewed, and 97 articles were chosen for full-text review by two authors independently. Furthermore, 89 articles were excluded in compliance with the PICOS question, and eight studies were chosen for qualitative analysis. Hence, the review comprised two RCTs and six prospective clinical studies. The time efficiency of the implant-supported FPDs was examined in four investigations, three of which used the Trios 3 scanner and one used the Intero scanner. The three-dimensional accuracy of DIT and CIT was compared in six clinical comparative studies. One of the RCTs was rated to have a high risk of bias and the other with a moderate quality of evidence. The six prospective studies were rated to have high-quality of evidence. The findings of this review indicate the prospective applicability of future intraoral scanning systems. The DIT was reported to be outstanding in terms of patient preferences and total fabrication time efficiency. Additional in vivo studies are needed to establish the therapeutic usefulness and time efficiency of integrating DIT in more comprehensive settings.

Automated Remodelling of Connectors in Fixed Partial Dentures.

In this study, an approach for automated parametric remodelling of the connector cross-sectional area in a CAD model of a given fixed partial denture (FPD) geometry was developed and then applied to a 4-unit FPD. The remodelling algorithm was implemented using Rhinoceros and the Grasshopper plugin. The generated CAD models were used to perform a finite element analysis with Ansys to analyse the stress distribution in an implant-supported 4-unit FPD for different connector designs. The results showed that the type of connector adjustment matters and that the resulting stress can be significantly different even for connectors with the same cross-sectional area. For tensile stresses, a reduction in the connector cross-sectional area from the gingival side showed the highest influence on each connector type. It can be concluded that the developed algorithm is suitable for automatic connector detection and adjustment.

Assessment of Various Risk Factors for Biological and Mechanical/Technical Complications in Fixed Implant Prosthetic Therapy: A Retrospective Study.

The study group consisted of 67 edentulous patients (mean age: 63.88 ± 11.709 yrs; 20 males, 47 females) with implant prosthetic therapy for posterior edentulism. A total of 76 implant-supported fixed partial dentures (IP-FPDs) and 178 implants were assessed using clinical and paraclinical assessments. Risk factors for biological complications (peri-implantitis) and technical complications were determined by using the Pearson Chi-squared test and multivariate analysis. The implant success (the absence of biological and mechanical/technical complications) was 66.30%. The prevalence of biological complications was 13.5%. The prevalence of technical complications was 28.70%. Variables that were associated with a higher risk of peri-implantitis were poor oral hygiene and bruxism. In univariate analysis, poor oral hygiene increased the risk of peri-implantitis 5.778 times and bruxism 5.875 times. Variables that were associated with a higher risk of mechanical/technical complications were age group > 60 yrs, smoking, history of periodontal disease, and bruxism. In univariate analysis, the risk of technical complications increased 4.14 times for patients in the age group > 60 years (vs. age group 40-60 years) and 20.5 times for patients with bruxism. Bruxism and smoking were significant predictors of mechanical/technical complications in the multivariate model. In univariate models, patients with poor oral hygiene and bruxism have an increased risk of peri-implantitis. In multivariate models, we did not identify significant predictors of peri-implantitis. Age group > 60 yrs, smoking, history of periodontal disease, bone grafting, and bruxism are risk factors for the increase in the mechanical/technical complication rate. In the multivariate model, smoking and bruxism are significant predictors of the mechanical/technical complications.

Finite Element Analysis: Connector Designs and Pontic Stress Distribution of Fixed Partial Denture Implant-Supported Metal Framework.

This virtual study was designed to evaluate the stress-deformation of a metal fixed partial dentures (FPDs) pontic under different loads using two different connectors. The STL file was generated for a RPD of two implant-supported restorations. The Co-Cr metal substructure was designed with two types of connector design. The pontic is connected to implant-supported crowns with square and round shape connectors. This study was designed for a cementless-retained implant-supported FPD. Finite element modeling (FEM) is used to assess the stress and deformation of the pontic within a metal substructure as the FEM might provide virtual values that could have laboratory and clinical relevance. The Co-Cr alloy mechanical properties like the Poisson ratio and modulus of elasticity were based on the parameters of the three-dimensional structure additive method. Nonparametric analyses (Mann-Whitney U test) was used. The use of square or round connectors often resulted in non-significant changes in stress, and deformation under either three or each loaded point on the occlusal surface of a pontic (P > 0.05). However, the deformation revealed distinct variations between loads of the three points compared to each loaded point (P ≤ 0.05). According to this study data, the pontic occlusal surface appears to be the same in stress and deformation under different loads depending on whether square or round connectors are used. While at the same connector designs, the pontic occlusal surface deformed significantly at three loaded points than it did at each point.

Survival of tooth-implant connections: A systematic review and meta-analysis.

Implant-supported prostheses have considerable biomechanical advantages in partially edentulous patients when compared to other prosthetic options. Given the steady drop in the frequency of patients reporting with complete edentulism, it is not unusual to see situations where teeth and implants can be splinted to provide support for fixed prostheses. A tooth implant prosthesis differs majorly from an implant-supported prosthesis in terms of force dissipation and design. The aim of this systematic review was to compare the survival rates of tooth-implant-supported prostheses with fully implant-supported and fully tooth-supported prostheses. Using the appropriate search terms, PubMed, Google Scholar, and other indexed journals were used to search the English-language literature. According to the review protocols and the PICOS inclusion criteria, the pertinent studies were chosen. The screening of appropriate studies, evaluation of study quality, and data extraction were carried out independently by two reviewers. The pooling of survival data by prostheses failure, implant failure, and marginal bone loss was used in the meta-analysis. The cumulative data of all included studies indicated that tooth-implant-supported prostheses showed a 5-year survival rate of 77%-84% and a 10-year survival rate of 72%. The pooled risk ratio for prostheses failure and implant failure was 0.99 and 1.76, respectively. These results were not statistically significant (P > 0.05). The pooled standard mean difference for marginal bone loss was 0.59, and the results were statistically significant (P < 0.05). A tooth-implant-supported fixed partial denture (FPD) has a similar survival rate when compared to implant-supported FPD or T-FPD.

A Safe Haven After Failed Implant-Supported Fixed Partial Dentures: Hybrid Prostheses - A Clinical Report

Despite the over 90%10-year survival rate of the dental implants, clinicians frequently encounter challenging cases with failed implant therapy. The vast majority of these cases are associated with poor treatment planning, and poor administration of the chosen treatment. In this case report, treatment procedu-res of a patient with the complaints of severe pain and nasal discharge which diagnosed to relate with the unsuccessful implant treatment was presented. The endoscopic examination revealed a fistula formation at the base of the nasal cavity generated from the implants placed in the premaxilla. The restorations were removed, the implants were explanted, and the surgical site was grafted. 6 months after the procedure, 6 implants were placed, and the patient was tre-ated with a metal-porcelain hybrid prosthesis following the osseointegration phase.

Internal and Marginal Fit Accuracy of Pre-sintered CAD/CAM Implant-Supported Frameworks Before and After Porcelain Layering.

Internal and marginal fit accuracy of an implant-supported fixed partial denture (I-FPD) along with passive fit are required for long-term clinical success. This study compared the fit accuracy of three-unit CAD/CAM-fabricated cementretained I-FPDs milled from pre-sintered cobalt-chromium (Co-Cr) and zirconia (Zr) and evaluated the effect of applying porcelain. Two implant analogs were positioned parallel at first premolar and first molar sites in an acrylic model. Their corresponding abutments were tightened with 25-Ncm torque force. Four groups were designed: two groups of I-FPD frameworks with pre-sintered Zr (ZrF) and soft millable Co-Cr alloy (SF) blocks, and two groups by applying porcelain to the Co-Cr (SP) and Zr (ZrP) frameworks (n = 4 in each group). Absolute marginal gap (AMG), marginal gap (MG), and internal discrepancies were measured. Kolmogorov-Smirnov, Levene, one-way analysis of variance (ANOVA), and Scheffe tests were used for statistical analysis using SPSS software version 22 at a significance level of .05. All measured criteria were significantly different from each other (all P values < .001). The rankings from the lowest gap to the highest gap for the main criteria were as follows: MG: SF < SP < ZrF < ZrP; AMG and internal discrepancies: SF < SP < ZrP < ZrF. Comparing molars and premolars, molars had smaller MGs, larger internal discrepancies, and smaller AMG in ZrP but larger AMG in SP. All three-unit CAD/CAM-fabricated cement-retained I-FPDs were in the clinically acceptable range of fit accuracy. The lowest and highest misfit values were observed in the SF and ZrF groups, respectively.

Effectiveness of implant-supported fixed partial denture in patients with history of periodontitis: A systematic review and meta-analysis.

This systematic review investigates the effectiveness of implant-supported fixed partial denture (IS-FPD) in patients with history of periodontitis (HP) vs. patients with no history of periodontitis (NHP). A literature search was performed on different databases on May 2020. Prospective and retrospective studies assessing survival (primary outcome), success and biological/mechanical complications of IS-FPDs in HP vs. NHP patients at ≥1year after implant loading were evaluated. Meta-analyses were conducted by estimating hazard ratio (HR), risk ratio (RR) and standardized mean differences (SMD) with 95% confidence intervals (CI) using random effect models. Of the initially identified 4096 articles, 349 underwent a full-text evaluation. Finally, 17 were included. Pooled data analyses showed that overall implant survival was significantly higher in the NHP than the HP group (HR=2.06; 95% CI=1.37-3.09; I2 =0%). This difference was noted when follow-up ≥5years. The risk of peri-implantitis was higher in HP than NHP patients (RR=3.3; 95% CI=1.31-8.3; I2 =0%), whereas the mean marginal bone level change over time was not different between the groups (SMD=-0.16mm; 95% CI=-1.04-0.73; I2 =98%). In partially edentulous patients receiving IS-FPDs, a history of periodontitis is associated with poorer survival rate and higher risk of peri-implantitis during a 5-10years period after implant loading.

Patient Satisfaction with Implant-Supported Monolithic and Partially Veneered Zirconia Restorations.

The digital workflow and the application of Computer-Aided Manufacturing (CAM) to prosthodontics present the clinician with the possibility of adopting new materials that confer several advantages. Especially in the case of zirconia, these innovations have profoundly changed daily practice. This paper compares the satisfaction and perception of patients who received implant-supported single crowns (SC) and fixed partial dentures (FPD) made from zirconia, either monolithic or partially veneered, after 3 years of follow-up; the success and survival rate of these restorations were also measured. Forty patients, who had been previously treated with implant-supported SC or FPD, either monolithic or partially veneered, and submitted to a yearly maintenance program, were recalled 3 years after their treatment and requested to complete an 8-question questionnaire regarding their perceptions of the treatment. Any mechanical or biological complication that had occurred from the time of delivery was also recorded. Patients that experienced ≥1 complication were less likely to be prone to repeat the treatment. The 3-year success rate was 92.6% for monolithic restoration and 92.3% for partially veneered restoration, while the survival rate was 100% for both restorations. The 3-year follow-up found that monolithic and partially veneered zirconia restorations are both well-accepted treatment options, and patients preferred the veneered restorations (0.76, p < 0.05) from an aesthetic point of view. According to our results, monolithic and veneered zirconia restorations are both reliable treatment options and are both equally accepted by patients.

Implant supported fixed partial denture is a viable fixed option to distal extension edentulous spaces

Background: Rehabilitating the partial edentulous space, especially in the distal extension area, is a daunting task for the prosthodontist. If the opposing arch has natural teeth or a fixed partial denture (FPD), the maxillary or mandibular distal extension edentulous spaces can be restored with either attachment-retained removable dental prosthesis or implant-supported fixed dental prosthesis. Case Report: A 55-year-old male presented with missing 17, 23, 24, 25, 26, and 27 in the maxillary posterior region with an implant-supported FPD in 43, 44, and 45 regions and 36 and 37 were treated for root canal. The clinical condition was diagnosed as Kennedy Class I in the maxillary posterior region and Kennedy Class II partial edentulous space in mandible. The treatment options given to the patient were either a removable partial denture or an implant-supported FPD. As the patient preferred the fixed dental prosthesis, the case was successfully managed with implant-supported fixed dental prosthesis in the distal extension partial edentulous area. Conclusion: Implant-supported fixed dental prosthesis is the only effective treatment for distal extension edentulous space for persons who desire to have a fixed prosthesis.

Evaluation of Fracture Load of Cement-, Screw-, and Multiscrew-Retained Abutments for Implant-Supported Fixed Partial Dentures.

The purpose of this in vitro study was to evaluate the load-to-fracture values of cement-, screw-, and multiscrew-retained abutments for implant-supported fixed partial dentures (FPDs). Thirty-six implants with a diameter and length of 4.5 and 13 mm, respectively, were used to prepare 18 samples of FPDs. Based upon the variations on abutment design, the FPDs were divided into three categories as follows: cement-retained, screw-retained, and multiunit screw-retained abutments. Using a chewing simulator, cyclic loads of 1,250,000 load cycles with a load of 70 N were applied on all samples to simulate 5 years of human functional chewing. The samples were loaded until failure using an electromechanical test machine. Sample-size estimation was done, and fracture-load values were recorded as means and corresponding standard deviations; group comparisons were done using one-way analysis of variance and Tukey post hoc tests. A P value < .01 was considered as an indicator of statistical significance. The fracture-load values for cement-, screw-, and multiunit screw-retained abutments were 2,109.2 ± 139.6 N, 3,888.8 ± 70 N, and 3,319.4 ± 218.9 N, respectively. The load-to-fracture values were significantly higher in screw-retained abutments (3,888.8 ± 70 N; P < .001) than in cement-retained (2,109.2 ± 139.6 N) and multiunit screw-retained abutments (3,319.4 ± 218.9 N). Screw-retained implant-supported FPDs withstand higher occlusal forces compared with cement- and multiunit screw-based retention techniques. However, the results should be cautiously interpreted, as they were based on a relatively small sample size.

Digital approach to fabricating a retrofitted abutment for reuse of an existing implant-supported fixed partial denture after the failure of an implant

The failure of an implant that supports an implant-supported fixed partial denture (ISFPD) may result in a failure of the prosthesis. Although fabricating a new ISFPD after replacing the implant is ideal, patients may hope to reuse the existing ISFPD because of financial constraints. A technique for rescuing a 6-unit metal-ceramic ISFPD with computer-aided design and computer-aided manufacturing (CAD-CAM) technology is described.

Retrospective clinical evaluation of 2- to 6-unit implant-supported fixed partial dentures: Mean follow-up of 9 years.

Implant-supported fixed partial dentures (ISFPDs) are one of the most common options to rehabilitate partially edentulous patients. To assess the clinical outcomes of ISFPDs. This retrospective study included all patients treated with ISFPDs with 2 to 6 prosthetic units at one specialist clinic. Implant/prosthesis failure and technical complications were the outcomes analyzed. Six hundred and forty-two patients with 876 ISFPDs (2241 implants) were included, followed up for 108.0 ± 76.2 months. Eighty-eight prostheses and 112 implants (26 before, 86 after prosthesis installation) failed. The estimated CSR of ISFPDs at 30 years was 72.7%. Smokers presented lower implant survival than nonsmokers. Two hundred and ninety-nine ISFPDs (33.2%) presented technical complications. Bruxism was a factor to exert a higher risk of screw and implant fracture, and ceramic chipping. ISFPDs with cantilever presented higher risk of failure, and screw loosening/fracture. Prostheses supported by implants with internal abutment connection or with two pontics had higher risk of presenting ceramic chipping. Extension of the prosthesis did not seem to exert influence on prosthesis failure/complications. ISFPDs presented good long-term prognosis. Implant failure was the main reason for ISFPD failure. The results suggest that bruxism and the presence of cantilever may contribute to the increased rate of mechanical complications and prosthesis failure.

Esthetic evaluation of single implant restorations, adjacent single implant restorations, and implant-supported fixed partial dentures: A 1-year prospective study.

Peri-implant soft tissues esthetics varies and depends on the restoration type such as implant-supported single crowns, adjacent multiple single crowns, and fixed partial dentures (FPD). The aim of this prospective study was to assess the esthetic outcome of the peri-implant soft tissues of (NobelBiocare™) implant-supported single crowns, adjacent multiple single crowns, and FPD. A potential association between the esthetic risk profile and the esthetic outcome was assessed. Between 03/11 and 03/17, 300 NobelActive implants were installed in 153 partially edentulous patients. Prior to the fabrication of the final restoration, the esthetic risk profile (ERP) of the patient was determined. The pink esthetic score (PES) and white esthetic score (WES) were assessed by three investigators at 6 and 12 months post-insertion of the final restoration. Patients' appreciation was assessed on a visual analogue scale (VAS) at the 1-year follow-up. The clinical acceptable limit for PES (≥6) was achieved in 56% to 68% of the single crowns at 6 and 12 months, respectively. Clinically unacceptable PES scores were recorded for 48% of the adjacent multiple single crowns and 63% of the FPDs at both time points. The association of a high ERP with WES and PESWES was noticed for single implant-supported crowns. For the latter restoration type, a ≤5 mm distance between the crestal bone level and the proximal contact positively influenced the PES and combined PESWES scores. No correlation was found between PES or WES and patient satisfaction. Mesial papilla formation was more pronounced compared to the distal one for the single implant crowns and for implant-supported FPD. When high esthetic demands are expected, assessment of ERP prior to implant treatment is advised in order to estimate a realistic outcome.