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Aim: To investigate fully edentulous patients rehabilitated with cantilever-fixed implant-supported restorations and to analyse which complications are reported for this type of treatment., Materials and Methods: Two operators screened the literature (MEDLINE, EMBASE) and performed a hand search on the main journals dealing with implantology and prosthetics until 31 December 2017. Only articles that considered cantilever implant-fixed restorations with at least 10 patients and with a mean follow-up of at least 5 years were selected. The outcome variables were survival of implants and prosthesis, mechanical, technical and biological complications, marginal bone loss. The review was performed according to the PRISMA statements. The risk of bias was evaluated for each article. Failure and complication rates were analysed using random effect Poisson regression models to obtain summary estimate of 5- and 10-year survival and complication rates., Results: Fourteen papers for fully edentulous patients were selected. The estimated 5 to 10 years survival rate was calculated to be 99.00% and 96.7% for the implants and the prosthesis, respectively. A total of 299 complications (technical and biological) were reported with a cumulative 5-10 years complication rate of 44.41% and 39.46% for the patients and for the prosthesis, respectively., Conclusions: There is evidence that cantilever can be successful treatment in fully edentulous patients., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objectives: The aim of the present publication was to report on the EAO Workshop group-4 discussions and consensus statements on the five reviews previously prepared. These reviews provided the scientific evidence on the effect of crown-to-implant ratio, on reconstructions with cantilevers in fully and partially edentulous patients, on biological and technical complications of tilted in comparison with straight implants, and on the effects of osseointegrated implants functioning in a residual dentition., Material and Methods: The group discussed, evaluated, corrected where deemed appropriate, and made recommendations to the authors regarding the following five reviews submitted: (a) Is there an effect of crown-to-implant ratio on implant treatment outcomes?; (b) Implant-supported cantilevered fixed dental rehabilitations in fully edentulous patients; (c) and in partially edentulous patients; (d) Biological and technical complications of tilted implants in comparison with straight implants supporting fixed dental prostheses; (e) What are the adverse effects of osseointegrated implants functioning among natural teeth of a residual dentition? Based on the five manuscripts and the discussion among the group as well as the plenum members, the major findings were summarized, consensus statements were formulated, clinical recommendations were proposed, and areas of future research were identified., Results: Crown-to-implant ratios ranging from 0.9 to 2.2 did not influence the occurrence of biological or technical complications also in single-tooth restorations. Reconstructions with cantilevers for the rehabilitation of fully and partially edentulous jaws showed high implant and reconstruction survival rates. In contrast, the rate of complications-in particular associated with veneering material-was high during the observation period of 5-10 years. The data reported were primarily derived from studies with high risk of bias. The data for single-implant reconstructions were small. There was no evidence that distally tilted implants were associated with higher failure rates and increased amounts of marginal bone loss. The data supporting these findings, however, were at high risk of bias and frequently incompletely reported. Frequent positional changes occurred between the natural teeth and the implant-supported restorations. These changes were more pronounced in younger individuals, and even though they were reduced with age, they still occurred in adult patients. Even though these changes were frequent, potential implications for the patient are unclear., Conclusions: The use of single-tooth restorations with crown-to-implant ratio in between 0.9 and 2.2 may be considered a viable treatment option. Multiunit reconstructions with cantilevers are a viable treatment option in fully and partially edentulous patients. Clinicians and patients should be aware, however, that complications are frequent and primarily related to resin material used for veneering. There is some evidence that tilting an implant does affect stability of the implant and the surrounding bone. Treatment options to tilted implants should carefully be considered, as the effect on soft tissues and on prosthesis behavior is poorly reported for tilted implants. Positional changes in the dentition in relation to implant-supported restorations occur frequently. The patient should be informed about the possible need for a treatment related to these changes in the long term., (© 2018 The Authors. Clinical Oral Implants Research Published by John Wiley & Sons Ltd.)

Objectives: To investigate in which clinical situations a cantilever fixed implant supported restorations can be a treatment alternative and which complications are reported., Materials and Methods: Two operators screened the literature (MEDLINE, EMBASE) and performed a hand search on the main journals dealing with implantology and prosthetics until 31 December 2017. Only articles that considered cantilever implant fixed restorations with at least 10 patients and with a mean follow-up of at least 5 year were selected. The outcome variables were survival of implants and prosthesis, mechanical, technical and biological complications, marginal bone loss. The review was performed according to the PRISMA statements. Risk of bias assessment was evaluated. Failure and complication rates were analysed using random effect Poisson regression models to obtain summary estimate of 5- and 10-year survival and complication rates., Results: A total of nine papers were selected for partially edentulous patients and reported high survival rate of the prosthesis. The estimated survival rate for 5-10 years was calculated to be 98.4% for the implants and 99.2% for the rehabilitations. Mechanical, technical and biological complications were reported with a cumulative 5-10 years complication rate of 28.66% and 26.57% for the patients and for the prosthesis, respectively. Two papers for single implant supporting 2-unit cantilever were not sufficient to draw conclusions., Conclusions: There is evidence that cantilever can be successful treatment in partially edentulous patients. In two adjacent edentulous sites, data are not yet sufficient., (© 2018 The Authors. Clinical Oral Implants Research Published by John Wiley & Sons Ltd.)

Introduction: Prosthetic complications on implant-supported restorations have been documented in several papers published in the literature. Several manufacturers are present on the market but results are often cumulated and may thus be misleading. The objective of the present review is to assess the prosthetic complications of implant-supported restorations with particular interest of the results obtained with prostheses from different manufacturers., Evidence Acquisition: A manual search of Medline/PubMed was carried out up to June 2016, yielding a total of 6832 articles, which were narrowed down to 1450, then 347 abstracts to include 55 papers after full text reading. Papers with at least 5 years of follow-up reporting on prosthetic complications of single and fixed partial prosthesis were included. Prosthetic complications were divided into mechanical and technical complications, and reported in a table., Evidence Synthesis: Overall 14.4% of prosthetic complication was found for a total of 6623 restorations followed for an average of 7.4 years (range 5-16 years). Results where then sorted and compared. Single crowns were affected by 1.4% of mechanical complications and 10.9% of technical complications after a mean of 7.4 years. Fixed partial prosthesis were affected by 2.5% of mechanical complications and 18% of technical complications. Screw-retained and cemented restorations were calculated to have a 5 years rate of complications of 21.2% and 9.3%, respectively, which demonstrated a statistically difference with fisher exact test with P<0.1. Only 3 manufacturers presented more than 10 articles and were directly compared with Fisher's exact test with P<0.1. The incidence of overall complications was estimated to be after 5 years of 11.2%, 10.8% and 13.8% for Straumann, Nobel, and Astratech, respectively, but dividing results in mechanical and technical complications, gave different results. Straumann was estimated to have less mechanical complications after 5 years in respect to Nobel and Astratech, but the three were similar for technical complications., Conclusions: although studies present very different material and methods and do not report all data, some conclusions can be made. The difference between mechanical complications lead the authors to suppose that there might be a difference in results obtained by different implant abutment connections. It is also noticed that all papers were published by expert clinicians and universities research centers that apply rigid surgical and prosthetic protocols and use original abutments.

Purpose: The aim of this study was to verify the reliability of a system for the fixed retention of complete maxillary prostheses supported by four implants with a follow-up of 2 years., Material and Methods: Patients were treated between September 2009 and December 2010 with four Straumann Bone Level SLActive implants supporting a complete prosthesis (CPs). The two distal implants were positioned mesially to the maxillary sinus and with a mesio-distal inclination ≤ 30° in order to reduce the distal prosthesis cantilever. An immediate loading surgical protocol was used. The CPs were planned to be fixed to multibase abutments to test their retention for a fixed rehabilitation. Clinical and radiographic parameters as probing pocket depth (PPD), bleeding score (mBI), plaque index (PI), and marginal bone loss (MBL) were assessed at a 1- and 2-year follow-up visits. Moreover, any biological and prosthodontic maintenance events were recorded. Clinical and radiographic parameters changes were analyzed., Results: Twenty-one patients treated with a total of 84 implants completed the 2-year examination period. Four patients were lost to follow up. No technical complication was recorded. Also, no implant, reconstruction, or abutment failures were observed. Therefore, an implant and prosthetic survival rate of 100% were achieved after 2 years. The mean periodontal parameter scores after 2 years of function were 2.6 mm for PPD (SD 0.8 mm), 0.3 for mBI (SD 0.5 mm), and 1.2 for PI (SD 0.4 mm) indexes, respectively. In addition, the mean MBL score measured at the 2-year follow-up visit was -0.34 mm (SD of -0.45 mm). Furthermore, no peri-implant soft tissue inflammation or peri-implant infection was observed., Conclusions: It has been shown that immediate loading of four implants positioned anteriorly to the maxillary sinus could be a reliable treatment procedure to support fixed complete restorations., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Purpose: While extensive references are present in the literature dealing with the correlation between subjective and objective evaluation of tooth shade, there is a lack of information on this correlation regarding the soft tissue color. The purpose of this experimental study was to verify whether a correlation between the objective and subjective evaluation exists in analyzing soft tissue color., Material and Methods: A total of 39 patients with at least one implant-supported restoration in the anterior maxilla were included in the study. The shade of the peri-implant mucosa was compared with the shade of the gingiva at the adjacent tooth in a subjective and in an objective manner. The subjective evaluation was performed by five dental professionals (prosthodontist, periodontist, general dentist, dental hygienist, and dental assistant) in a subjective scale (ranging from 1 to 4). The objective evaluation was obtained by means of a spectrophotometer in a CIELAB* Color Scale, and the differences were evaluated through formula ΔE=[(ΔL)²+(Δa)²+(Δb)²]¹/². To correlate the subjective and the objective evaluation, for each arithmetical median value of the subjective evaluation, a mean value of objective evaluation has been calculated, and the Spearman's rank correlation coefficient has been used. The differences have been also analyzed for thin and thick tissue biotypes., Results: The mean ∆E value for the subjective evaluation between peri-implant soft tissue and adjacent tooth gingival tissue was ∆E = 9.74. Also, mean ∆E values of 10.35 and 7.54 have been reported for thin and thick biotypes, respectively. Mean values of ∆E = 6.63, 8.54, and 15.54 were presented by median values of 1 (perfect matching), 2 (good matching), and 3 (clinically distinguishable), respectively. The threshold for the distinction of differences of mucosal color by the human eyes between perfect or good matching and distinguishable values has been calculated in ∆E = 8.74., Conclusions: Within the limitation of this study, a correlation between the subjective and the objective evaluation of the peri-implant soft tissue exists and the threshold for the distinction of mucosal color differences between perfect or good matching and distinguishable subjective values has been calculated in ∆E = 8.74 in the objective evaluation., (© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Aim: The aim of this study was to verify if the three-dimensional implant position in fresh alveolar socket may influence the maintenance of stable gingival margins around single premolar restorations with immediate implant placement., Methods: After 16 weeks of healing, implants were loaded with single crowns. Documentation consisted in peri-apical radiographs taken: before treatment; at the time of implant placement; at the time of prosthetic rehabilitation and 12 months after the start of prosthetic function. Parameters assessed were: the presence/absence of inter-proximal papilla; the inter-implant-tooth distance (ITD); the distance from the base of the crown contact-point to the inter-dental bone crest (CPB); and the buccal-gingival tissue modifications. ITD, CPB values and the modification of buccal-gingival tissue were determined using an image processing software., Results: Twenty-one healthy patients with thick gingival biotype, with a total of 21 maxillary premolars scheduled for extractions were enrolled. Following extraction, implants were immediately positioned. A 100% of implant survival rate was observed after 12 months of function. The presence of the mesial papilla was significantly correlated with the mean mesial CPB value (P = 0.0519 by means of two-tailed Mann-Whitney U-test). No significant correlation was found between the mesial papilla presence and the mean mesial ITD score (P = 0.7722 by means of two-tailed Mann-Whitney U-test). Furthermore, the presence of the distal papilla was not significantly correlated with the mean distal ITD and CPB values: scores of 0.7195 and 0.8225 were calculated respectively., Conclusion: In the premolar area, the relationship between the presence of a complete inter-proximal papilla and ITD parameter was not significant (P > 0.05). The relationship between the presence of a complete inter-proximal papilla and CPB parameter still remain unclear. Nevertheless, a more large sample size is required to confirm this trend. Moreover, it was observed that the buccal-gingival tissue withdrew in the range 0-1 mm after 1 year of prosthetic function., (© 2012 John Wiley & Sons A/S.)

Purpose: The aim of this clinical research on implant-supported restorations is to analyze, through spectrophotometric digital technology, the influence of the abutment material on the color of the peri-implant soft tissue., Material and Methods: Twenty patients received an endosseous dental implant in the anterior maxilla. At the time of each definitive prosthesis delivery, an all-ceramic crown has been tried on gold, titanium and zirconia abutment. After the insertion of each single abutment, the peri-implant soft tissue color has been measured through a spectrophotometer. Also, the thickness of the facial peri-implant soft tissue was measured at the level of the implant neck through a caliper. A specific software has been utilized to identify a specific tissue area and to collect the data before the statistical analysis in Lab* color space. The normality of the quantitative variables was verified by means of the Shapiro-Wilk test. Simple linear correlation between quantitative variables was evaluated by using Pearson's coefficient. The results on the performance of the abutment materials with regard to the color measurements and the overall measurement ΔE were described by computing the least-square means. The significance of differences among types of abutment was verified by means of the Scheffe test for multiple comparisons., Results: For all the abutments used, the color of the peri-implant soft tissue appeared to be significantly different from the one of the contra-lateral tooth (ΔE>8.5). Significantly higher (P<0.05) difference were present with the use of titanium abutments (11 ± 0.4) when compared with the results of gold (8.9 ± 0.4) and zirconia (8.5 ± 0.4) abutments. No correlation has been demonstrated between soft tissue thickness and degree of color difference (P>0.25)., Conclusions: Within the limitation of the present study, the peri-implant soft tissue color appears to be different from the soft tissue color around natural teeth, no matter which type of restorative material is selected. When titanium abutment was selected, significantly higher differences were present than those obtained with gold or zirconia abutments. The thickness of the peri-implant soft tissue did not appear to be a crucial factor in the abutment impact on the soft tissue color., (© 2010 John Wiley & Sons A/S.)

The use of technologies that merge computerized tomography X-ray imaging and 3-dimensional (3D) planning software allow the surgeon to digitally elaborate on the computer the position, length, and diameter of every implant to be placed. Following this approach, the placement is guided in a 3D digital model, and the implants are placed in the final position avoiding eventual anatomic structures. In this case report, the patient's remaining mandibular teeth were extracted, and the patient received 8 implants with the help of a computer surgical guide. The case was planned using SimPlant and a bone-supported guide. Because of the high precision of the planning, it was possible to realize a provisional rehabilitation before the actual surgery. The planning allows placement of parallel implants to optimize the prosthetic procedure and outcome. An immediate provisional implant was fixed with a flow composite on the temporary abutments and then refined in the dental laboratory. The patient received the provisional rehabilitation the same day of the surgery. After 6 weeks of healing, the final impression was taken and the prosthesis was finalized with a computer-aided design/computer-aided manufacturing titanium full-arch screwed framework with composite veneering. A 6-month follow-up showed good integration of the prostheses and success of all 8 implants. The use of surgical computer-guided planning changes the surgeon's approach: whereas before the use of conventional guides permitted a certain degree of offset from what was planned, the use of computer guides allows the implant to be inserted in a far more precise way. It is obvious that careful planning is the key factor to avoid implant misplacement.

Background: Reconstructive procedures present a higher rate of biological costs due to the necessity of bone harvest and grafts, use of semipermeable barriers etc. On the hand, implant supported cantilever prostheses could allow a simpler rehabilitation procedure., Aims: The aim of the present study was to assess the clinical outcome of patients treated with implant-supported fixed partial dentures (FPD) with cantilever after a mean follow-up time of 8 years., Material and Methods: The study included 45 consecutive partially edentulous patients treated between January 1994 and August 2006 with 59 partial cantilever fixed prostheses supported by 116 ITI implants. The primary outcome variable considered was the presence of complications at the subject and bridge level; the secondary outcome variable was marginal bone loss (MBL). The frequency of complications was analyzed according to cantilever location and opposite dentition and tested by Fisher's exact test. A multilevel regression model was constructed to analyze the factors influencing MBL with three levels: subject as the highest, and then implant and site. During the follow-up period, 11 implants showed a bone loss exceeding the limit for success, out of which two implants showed an infection of the peri-implant tissue., Results: After an average observation of 8.2 years of cantilever prostheses loading, the implant success and survival rates were 90.5% and 100%, respectively. Besides, the prosthetic success and survival rate were 57.7% and 100%, respectively., Discussion: None of the predictors included in the multilevel model presented a significant impact on the bone loss between baseline and the follow-up examination., Conclusions: The authors concluded that the prognosis of implant-supported FPDs and marginal bone loss at implants were not influenced by the position or the length of the cantilever, the location of the bridge and type of opposite dentition. Implant-supported fixed cantilever prosthesis can be considered a suitable treatment choice.

Background: Gingival esthetics around dental implants have become a main focus for clinicians. This study analyzed the surgical, prosthetic, and anatomic factors involved in the management of peri-implant tissues., Methods: Forty-eight subjects with one tooth scheduled for tooth extraction and immediate implant placement were included in the study. After healing, the implants were restored with single-crown fixed prostheses. The following parameters were assessed after 12 months: presence/absence of the interproximal papilla, interimplant-tooth distance (ITD), distance from the base of the contact point to the interdental bone (CPB), and soft tissue biotype. ITD and CPB values were derived from computer analysis of periapical radiographs. A statistical analysis determined the effect of ITD and CPB on the presence of the interproximal papilla., Results: Papilla was significantly present (P <0.05) for ITD of 2.5 to 4 mm in anterior and posterior areas and for CPB < or =7 mm in posterior areas. Thick biotype was significantly associated (P <0.05) with the presence of the papilla., Conclusions: The combination of surgical and prosthetic plans represents the key factor to optimize predictability in single-implant esthetics. The recommended interproximal distance between the implant and the adjacent tooth is 2.5 to 4 mm. The distance from the contact point to the interdental bone is recommended to be <7 mm. Papilla presence is also correlated with a thick gingival biotype.

Objectives: To assess the clinical conditions, patient's satisfaction and functional outcomes in oral neoplasia patients with hemimandibulectomy, bone reconstruction and implant-supported prosthesis., Material and Methods: Twelve patients after mandibular resection (with and without condyle), reconstruction and successful fixed implant-supported prosthesis rehabilitation were examined. Patients underwent clinical evaluation and filled in a questionnaire about their satisfaction toward oral functions. Surface electromyography (EMG) of the masticatory muscles was performed during a 15-s unilateral gum chewing test. EMG potentials were standardized as percentage of a maximum clench on cotton rolls and compared with reference data obtained from 20 healthy subjects., Results: Excellent clinical and radiological parameters were found. Patients stated a decreased post-rehabilitation satisfaction toward mastication and phonetics, but an increased attention to oral care. Only patients with condylar resection reported augmented esthetic scores. In both the resected and the remaining sides, chewing frequency was higher in the patients than in the reference group (Wilcoxon's rank-sum test, P<0.001). Pooled muscle activities (sum of the integrated areas of the EMG potentials over time) were larger in patients than in control subjects, particularly in the non-operated side (P=0.001). The percentage contribution of working-side muscular activity in the operated side was similar to reference values, but significantly inferior in the opposite side (P<0.001). The patterns of muscle contraction during unilateral chewing were more variable in the reconstructed patients than in control subjects; the difference was significant only in the non-operated side (P<0.01)., Conclusion: Post-rehabilitation median scores of the questionnaire indicated a positive judgment of the treatment. EMG analysis showed that functional recovery in hemimandibulectomy patients was satisfactory, although some alterations were observed in the non-operated side of mastication.

The purpose of the following study was to evaluate the medium- to long-term prognosis of implant-supported cantilever fixed prostheses, and to establish to what degree this is influenced by factors such as length, type of cantilever (mesial or distal), and opposite dentition versus cantilever prostheses. This study was performed on a sample of 38 partially edentulous patients treated between January 1994 and March 2001 with 49 partial cantilever fixed prostheses supported by 100 implants. Marginal bone resorption (MBL) has been studied and used as a reference parameter to define therapeutic success. The MBL measurement was made possible by transposing X-ray images of patients selected on a PC and then using a software program. Statistical analysis was carried out for possible correlation between peri-implant bone resorption and the parameters considered in this study: length and type (mesial or distal) of cantilever and opposite dentition to cantilever prostheses. Seven years after loading cantilever prostheses, the overall cumulative implant survival rate (OCSR) was 97%, and the prostheses success rate is 98%. Mesial cantilever prostheses registered a lower success rate (97.1%) than distal cantilever prostheses (100%). Furthermore, a better prognosis was not observed when the opposite dentition of the prostheses comprised natural teeth, or fixed prostheses on natural teeth, when compared with the cases in which opposite teeth were implant-supported fixed prostheses. The authors concluded that medium-term prognosis of implant-supported cantilever fixed prostheses and traditional implant-supported fixed prostheses was comparable. However, a thorough pre-treatment analysis of risk factors regarding implant-supported prosthesis survival is important.

This prospective study has been designed to compare the results of immediate and delayed loading of implant-retained mandibular overdentures after a 2-year follow-up. Twenty patients have been randomly divided into two groups. Group 1 patients (test group) received four ITI implants in the intraforaminal area of the mandible. Octa abutments were immediately screwed on implants; 2 days after surgery, the implants were rigidly connected with a U-shaped Dolder gold bar and loaded with an overdenture. Group 2 patients (control group) received, in the same area, the same type and number of implants, which were left to heal according to the standard protocol. At 3-4 months, Octa abutments were screwed on the implants and the same prosthetic procedure of the test group was applied. The minimum follow-up period lasted 2 years, with recall appointments at 2 weeks, 1, 3, 6 months, 1 year and every following year postoperatively, evaluating: MPI, MBI, PD, Periotest and radiographic peri-implant bone resorption. Success criteria according to Albrektsson et al. were used. Only one implant out of the 40 of group 2 failed, whereas none failed in group 1. No statistical difference of the clinical parameters evaluated was noticed in the two groups. Therefore, immediate loading of implants, if connected with a U-shaped bar, can provide the same results of the 'traditional' technique as far as osseointegration and short-term survival rates of implants are concerned. Moreover, this method significantly shortens the treatment period, thus increasing patient satisfaction.