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Purpose: To retrospectively evaluate the clinical outcomes of immediately loaded zygomatic implants combined with anterior regular implants (hybrid zygoma) for the fixed rehabilitation of atrophic maxillae. Materials and Methods: A total of 18 patients were enrolled in this study and treated with the hybrid zygoma concept by an experienced surgeon. Followup visits were planned after 1 week, 3 weeks, 4 months, 6 months, then annually. At the last follow-up appointment (mean: 36 months after surgery; range: 24 to 52 months), the prostheses were unscrewed and the implants and periimplant tissues were examined. The primary outcome evaluated was implant success. Following the criteria proposed by Aparicio et al, implant success was classified in five grades, with grade I representing the best condition and grade V representing a failure. At the annual check-up, patients were asked to fill out a questionnaire to evaluate their satisfaction with their oral rehabilitation. Results: A total of 80 implants (34 zygomatic and 46 regular) were inserted. One zygomatic implant was lost in one patient, and two regular implants failed in two other patients. Of the zygomatic implants, 24 (70.6%) presented a success grade I, 9 (26.5%) a success grade II, and 1 (2.9%) a grade V. Sinusitis was the most common biologic complication, occurring in two patients (5.6%). Two patients showed unilateral upper lip paresthesia that was persistent at the last follow-up appointment. According to the annual follow-up visit questionnaire data, 72%, 89%, and 94% of patients declared that they were satisfied with their phonetic ability, chewing ability, and esthetics, respectively. Conclusion: Although zygomatic implants combined with anterior regular implants present a higher risk of complications than traditional implantology, they allow for immediately loaded full-arch fixed rehabilitation of patients with advanced atrophy of the posterior maxilla, which provides satisfactory chewing ability, esthetics, and phonetics. [ABSTRACT FROM AUTHOR]

The aim of the present report was to evaluate the clinical outcomes of edentulous jaws rehabilitated with the Brånemark Novum protocol over a 16-year period. Between April and November 2001, four patients (three males, one female) were rehabilitated with fixed full-arch rehabilitations supported by three immediately loaded implants following the Brånemark Novum protocol. Cumulative survival rates (CSRs) of the implants and prosthesis, bleeding on probing (BOP), Plaque Index (PI), probing depth (PD), implant stability quotient (ISQ; as measured through resonance frequency analysis [RFA]), and peri-implant bone resorption were evaluated over time, up to the 16-year follow-up. At 16 years of follow-up, no implant failed (CSR 100%) and no prosthesis needed to be substituted (CSR 100%). During the period between the 11th and 16th year of follow-up, bone level (mean: 2.2 mm at 16 years) and RFA values remained stable. At the 16-year follow-up, the implants presented high PI (79.2%) but low BOP (10.4%) values. Mean PD was 3.30 mm (range: 2 to 6 mm). One biologic complication was detected on a central implant (crater-form bone destruction), and several prosthodontic complications occurred during the 16 years (fractures of resin or teeth), the majority of which were registered on the same parafunctional patient. This is the first description of the Brånemark Novum protocol rehabilitation with a 16-year followup. The outcomes demonstrated very good long-term outcomes for this protocol. [ABSTRACT FROM AUTHOR]

Purpose: To compare clinical outcomes of immediate vs delayed implant loading in edentulous maxillae with full-arch fixed prostheses.Materials and Methods: Two patient groups were identified for this study: (1) the test group (TG), which included 34 patients (19 women, 15 men; mean age 56.7 years) treated with the Columbus Bridge Protocol with 4 to 6 postextractive implants loaded within 24 hours (163 implants total); and (2) the control group (CG), which included 15 patients (6 women, 9 men; mean age 59.96 years) treated with a traditional two-stage delayed loading rehabilitation using 6 to 9 implants inserted in healed sites (97 implants total). All patients were rehabilitated with full-arch fixed prostheses in the maxilla.Results: At the 10-year follow-up, no difference in the implant cumulative survival rate between the TG (93.25%) and CG (94.85%) was found. Mean bone loss was significantly lower in the TG (mean: 2.11 mm) compared to the CG (mean: 2.65 mm). All original prostheses were maintained and functioning satisfactorily.Conclusion: Maxillary full-arch immediate loading represents a valid alternative to the traditional delayed loading rehabilitation. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to analyze through a three-dimensional finite element analysis (3D-FEA) stress distribution on four implants supporting a full-arch implant-supported fixed prosthesis (FFP) using different prosthesis designs.Materials and Methods: A 3D edentulous maxillary model was created and four implants were virtually placed into the maxilla and splinted, simulating an FFP without framework, with a cast metal framework, and with a carbon fiber framework. An occlusal load of 150 N was applied, stresses were transmitted into peri-implant bone, and prosthodontic components were recorded.Results: 3D-FEA revealed higher stresses on the implants (up to +55.16%), on peri-implant bone (up to +56.93%), and in the prosthesis (up to +70.71%) when the full-acrylic prosthesis was simulated. The prosthesis with a carbon fiber framework showed an intermediate behavior between that of the other two configurations.Conclusion: This study suggests that the presence of a rigid framework in full-arch fixed prostheses provides a better load distribution that decreases the maximum values of stress at the levels of implants, prosthesis, and maxillary bone. [ABSTRACT FROM AUTHOR]

This prospective study reports the 6-year outcomes for patients rehabilitated with an immediate loading protocol of the maxilla (Columbus Bridge Protocol). In this study, 164 implants were inserted in 37 patients and loaded within 24 to 36 hours. Four implants failed during the first 6 months. At the 6-year follow-up, a mean bone loss of 1.52 mm was found. Significantly (P < .0083) less bone loss was found next to tapered implants compared with cylindric implants and next to machined collar implants compared with full acid-etched implants (P < .0083). No significant differences in bone loss were found in tilted versus upright implants or in mesial versus distal implant sites. In addition, there were no significant differences relating to either the degree of abutment angulation or the reason for tooth loss. [ABSTRACT FROM AUTHOR]

Purpose: This study compared the surgical protocol efficacy of immediate and delayed implant loading in edentulous maxillae opposed by natural or restored mandibular dentitions over an observational period of 6 years or longer. The selected outcome determinants included individual implant survival data, progressive measurements of peri-implant bone resorption, prosthodontic survival and success data, and report of complications. Materials and Methods: A convenience sample of 49 patients requiring fixed implant-supported maxillary prostheses was split into two groups. The test group (34 patients) was treated according to the Columbus Bridge Protocol, which prescribes the insertion of four to six implants, including distally tilted implants, and load within 24 hours. The control group (15 patients) was treated via a two-stage surgical protocol of 6 to 9 straight implants that were loaded a mean 8.75 months after stage-one implant surgery. Two hundred sixty implants (test: n = 163, control: n = 97) were placed, and all subjects were ultimately treated with screw-retained full-arch prostheses. Results: Two patients dropped out (one in the test group and one in the control group) by the time of the scheduled sixth annual visit. The other patients were followed up for 75.2 months (range: 72 to 90 months). At the 6-year follow-up, no differences in implant cumulative survival rates were found between groups. Significantly less bone loss was found in the test group (mean: 1.62 mm) compared with the control group (mean: 2.44 mm). All of the original prostheses were maintained throughout the study's observation period and were functioning satisfactorily at each patient's last recall appointment. Conclusion: Patients who received immediate and delayed implant loading in their edentulous maxillae demonstrated similar survival outcomes. However, less marginal bone loss was recorded around the immediately loaded implants over the study's 6-year follow-up period. [ABSTRACT FROM AUTHOR]

Purpose: This systematic review considers possible etiologic factors and definitions of peri-implantitis as reported in the recent literature. Materials and Methods: An electronic search of databases plus a hand search of the most relevant journals published between January 2005 and September 2012 were performed. Results: The electronic and manual searches yielded 640 and 14 titles, respectively. From the independent double-check of the titles and abstracts, 24 full texts were downloaded (18 clinical studies and 6 animal studies). After reading the full texts, 10 articles (4 clinical studies and 6 animal studies) were included in this review. None of the human articles selected provided sufficient evidence to address the research question, and no human clinical evidence is available to support a cause-effect relationship between peri-implantitis and bacterial accumulation and/or occlusal overload. The animal literature is also not unanimous regarding a specific peri-implantitis etiology. However, a correlation between periodontitis and smoking histories was cited as contributing to a higher incidence of peri-implantitis. Conclusion: The available scientific literature is characterized by an absence of a unanimous consensus regarding the etiology of peri-implantitis and its specific relationship to periodontitis. Furthermore, both the choice of the term peri-implantitis and its definition remain controversial. [ABSTRACT FROM AUTHOR]

Purpose: To measure the vertical occlusal forces transmitted through crowns made of different restorative materials onto simulated peri-implant bone. Materials and Methods: The study was conducted using a masticatory robot that is able to reproduce the mandibular movements and forces exerted during mastication. During robot mastication, the forces transmitted onto the simulated peri-implant bone were recorded using nine different restorative materials for the simulated single crown: zirconia, two glass-ceramics, a gold alloy, three composite resins, and two acrylic resins. Three identical sample crowns for each material were used. Each crown was placed under 100 masticatory cycles, occluding with the flat upper surface of the robot to evaluate the vertical forces transmitted. Two-way analysis of variance was used. Alpha was set at .05. Results: The statistical evaluation of the force peaks recorded on the vertical z-axis showed mean values of 641.8 N for zirconia; 484.5 N and 344.5 N, respectively, for the two glass-ceramics; 344.8 N for gold alloy; 293.6 N, 236 N, and 187.4 N, respectively, for the three composite resins; and 39.3 N and 28.3 N, respectively, for the two acrylic resins. Significant differences were found between materials (P < .0001), except for the comparison between gold alloy and one of the glass-ceramics. Conclusion: Composite and above all acrylic resin crowns were more able to absorb shock from occlusal forces than crowns made of zirconia, ceramic material, or gold alloy. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to compare survival rates and radiographic outcomes of immediate and delayed implant loading in edentulous maxillae.Materials and Methods: Forty-nine patients in need of maxillary full-arch treatment were randomized into two groups: test group (n = 34) treated following the Columbus Bridge Protocol with 4 to 6 implants loaded within 24 hours and a control group (n = 15) treated following the ad modum Branemark protocol with 6 to 9 implants loaded a mean 8.75 months after surgery. Two hundred sixty implants (test: n = 163, control: n = 97) were placed, and subjects were treated with screw-retained full-arch prostheses. Bone levels were measured at baseline and at 1, 2, and 3 years and analyzed using repeated-measures analysis of variance.Results: All patients appeared at all scheduled recall visits. No differences in cumulative survival rates were found between groups at 36 months. Ten implants (6.1%) failed in the test group; four (4.1%) failed in the control group. At 36 months, no prosthetic failures were detected. Significantly less bone loss was found in the test group at all time intervals (P < .001). The average bone level from the implant-abutment connection was 1.3 mm in the test group and 1.9 mm in the control group at 12 months, 1.5 mm and 2.2 mm at 24 months, and 1.6 mm and 2.3 mm at 36 months, respectively.Conclusion: In the edentulous maxilla, the Columbus Bridge Protocol involving immediate loading of implants placed in both healed and fresh extraction sites exhibited equivalent implant survival and less marginal bone loss at 3 years compared to the conventional two-stage delayed loading protocol. Int J Prosthodont 2011;24:294-302. [ABSTRACT FROM AUTHOR]

Many clinical studies have reported high survival rates for tilted implants. However, tilted implants transmit increased stress to bone when compared to vertically placed implants. Theoretical (computer-based), laboratory, and clinical studies are warranted to effectively address this issue. In this study, a 3-dimensional finite element analysis was performed to analyze the stress values surrounding tilted versus vertical implants. The results revealed laboratory and biomechanical evidence that distal tilting of implants, splinted in full fixed prostheses without cantilevers, reduced the amount of stress generated around the peri-implant bone when compared to the levels of stress seen in peri-implant bone with vertical implants and cantilevered segments in similar full fixed prostheses. [ABSTRACT FROM AUTHOR]

Purpose: This study describes a mechanical chewing simulator that is able to reproduce mandibular movements in 3 dimensions and the forces exerted during mastication. The aim of this work was to validate the described device, which can be used to test the ability of different restorative materials to withstand stress. Materials and Methods: To validate the masticatory robot, 5 identical samples for each of 3 different restorative materials (an acrylic resin, a composite resin, and a glass ceramic) were created. Each sample underwent 5 minutes of chewing in the robot. The forces transmitted to the simulated peri-implant bone were collected. Two-way analysis of variance was used to evaluate the results. Results: There were significant differences between the materials, and internal comparisons also showed significant differences (P< .0001). Conclusion: The different elastic moduli of the restorative materials significantly affected stress transmission at the simulated bone-implant interface, and the masticatory robot was able to identify this difference. The very low levels of variation confirm the precision of the machine during data collection and validate the reliability of the method, showing effective repeatability of the tests. [ABSTRACT FROM AUTHOR]

Purpose: This study was conducted to measure, in vitro, the chewing load forces transmitted through crowns made of different prosthetic restorative materials onto dental implants. Materials and Methods: A masticatory robot capable of reproducing the mandibular movements and the forces exerted during chewing was used. The forces transmitted to the simulated peri-implant bone during the robot mastication were analyzed using four different occlusal materials: three resin composites and one glass ceramic crown. Results: The ceramic crowns transmitted significantly greater forces (up to +63.06%, P< .0001) than the composite crowns tested. Conclusion: Composite crowns are better able to absorb shock from occlusal forces than crowns made of ceramic material. [ABSTRACT FROM AUTHOR]

Purpose: Severe anterior maxillary atrophy offers few implant-supported rehabilitation solutions to Quad Zygoma characterized by a wide anterior cantilever. One of the possible alternatives to consider before the quad zygoma is the extra-long nasal/trans-nasal implant placement. This retrospective multicentric study shows the predictability of nasal/transnasal implant placement in patients affected by severe anterior maxilla atrophy, with residual anatomical features that indicate this surgery. This specific remote anchorage can often be safely involved in immediate loading with other remote anchorages, such as zygoma and pterygoid implants. In this rehabilitation, it's mandatory to reduce the instability of the frameworks and mechanical stress that could unfavorably affect the implant's prognosis due to the overloading derived from anterior bending., Materials and Methods: In this retrospective multicentric study, 52 nasal or trans-nasal implants were inserted in 31 atrophic anterior maxillas (Cawood and Howell's class V-VI). All implants were successful after the healing period; even if 27 nasal implants reached an insertional torque equal to or greater than 50 n/cm2, the threshold value estimated to be able to support an immediate load., Result: All 52 implants were successful, so the proportion of success was 100%, with a 97.5% one-sided confidence interval of 88.8-100%. The success rate is achieved only if at least two of the following criteria are met: 1) a greater torque than 50 Ncm as a minimum sufficient condition to plan immediate loading; 2) after a healing period of 16 weeks, the secondary stability is clinically and radiographically evaluated to exclude possible coronal bone resorption: this condition allows the successive prosthetic finalization; 3) the possibility of carrying out a full arch rehabilitation with minimal anterior spread. Insertion torque was <50 Newton centimeters (Ncm) in 14 patients (45%) and 50 Ncm in 17 (55%). Mechanical load was delayed in the former and immediate in the latter. The proportion of torque <50 Ncm was higher in men than in women (69% versus 28%, p&#61;0.033). Immediate torque was not significantly affected by age., Conclusion: Although the sample is not extremely numerically significant, it conveys a clear and significant clinical, surgical indication as never before in the literature; we can state that nasal/trans nasal implants have been very useful in reducing the anterior cantilever and overcoming the anatomical limitations affecting conventional Quad Zygoma.

Objectives: Short-term results indicated that the Brånemark Novum ® protocol (Nobel Biocare AB, Goteborg, Sweden) allowed successful rehabilitation of mandibular edentulism with immediately loaded implants. Yet, long-term studies are lacking. The aim of the present retrospective study was to report the 11-year outcomes for patients treated according to this protocol., Material and Methods: Four patients treated according to the Brånemark Novum protocol (Nobel Biocare AB) were followed-up to evaluate implant and prosthesis cumulative survival rate (CSR), implant stability (RFA), marginal bone loss by periapical radiographs, probing depth (PD), and possible complications. Clinical and radiographic parameters were evaluated immediately after completion of the treatment and 1, 5, and 11 years after loading., Results: The 11-year implant and prosthesis CSRs were 100%. Implant stability (RFA values) remained stable over the 11-year follow-up. Small bone resorption was found next to distal implants (median 1 mm) after 11 years, while central implants showed greater bone resorption (median 4.5 mm). The PD (mean 3.75 mm at 11 years) grew together with marginal bone loss. One implant complication was detected on a central implant (crater-form bone destruction), and 10 prosthetic complications (fractures of resin or teeth), 80% of which registered on the same parafunctional patient., Conclusions: The 11-year results demonstrated that the Brånemark Novum protocol (Nobel Biocare AB) is a predictable technique with favorable long-term outcomes. This was a rigid protocol, which could be applied only in patients with specific anatomical characteristics of the lower jaw, but it had the merit of indicating the key factors for full-arch immediate loading rehabilitations., (© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)