vendex and Jaw--Edentulous

The aim of this split-mouth, randomized, double-blind, controlled clinical trial was to evaluate the influence of different insertion torque values for dental implants on bone- and angiogenesis-related marker profiles. Eighteen edentulous patients received dental implants and fixed complete-arch mandibular prostheses. The implants (n=36) were assigned randomly to two groups: reduced torque (n=18), with insertion torque <30Ncm; and conventional torque (n=18), with insertion torque ≥30Ncm. Levels of vascular endothelial growth factor (VEGF), placental growth factor, bone morphogenetic protein 9 (BMP-9), periostin, osteoprotegerin (OPG), and tartrate-resistant acid phosphatase (TRAP) in the peri-implant fluid were quantified at 7, 14, 30, and 120days after implant placement. Inter-group comparisons showed that VEGF and OPG levels were higher in the low-level torque group than in the conventional torque group on days 7 and 30, respectively (P<0.05). BMP-9 and periostin levels were higher in the conventional group than in the low-level torque group on day 120, and TRAP was up-regulated around implants inserted with conventional torque when compared to those inserted with lower-level torque at all time points evaluated (P<0.05). In conclusion, the use of different levels of torque for implantation of immediately loaded implants significantly influenced the levels of bone- and angiogenesis-related markers during early peri-implant repair.

Topics: Adult; Aged; Biomarkers; Cell Adhesion Molecules; Double-Blind Method; Female; Growth Differentiation Factor 2; Humans; Immediate Dental Implant Loading; Jaw, Edentulous; Male; Middle Aged; Osteoprotegerin; Placenta Growth Factor; Prospective Studies; Tartrate-Resistant Acid Phosphatase; Torque; Vascular Endothelial Growth Factor A

To evaluate the outcome of three (fixed-on-3 = Fo3) vs four (fixed-on-4 = Fo4) implants immediately restored with metal-resin screw-retained cross-arch prostheses in fully edentulous jaws.. Forty-eight edentulous or to be rendered edentulous patients were randomised in six centres (eight patients per centre) to the Fo3 group (24 patients: 12 maxillae and 12 mandibles) and to the Fo4 group (24 patients: 12 maxillae and 12 mandibles) according to a parallel group design. To be immediately loaded, implants had to be inserted with a minimum torque of 40 Ncm. Outcome measures were prosthesis and implant failures, complications and peri-implant marginal bone level changes evaluated up to 1 year post-loading.. One maxillary prosthesis per group was delayed loaded because implants could not be placed with a torque of at least 40 Ncm. Ten patients in the Fo3 group and four in the Fo4 group had implants placed flapless. One year after loading no drop out occurred. One patient of the Fo3 group lost three implants vs three patients of the Fo4 group who lost four implants, the difference being no statistically significant (risk difference = -0.08; 95% CI: -0.27 to 0.10; Fisher's exact test P = 0.609). One mandibular Fo3 and one maxillary Fo4 prosthesis failed. Six Fo3 patients were affected by complications vs three Fo4 patients (risk difference = 0.12; 95% CI: -0.10 to 0.34; Fisher's exact test; P = 0.461). Both groups lost marginal bone in a statistically significant way (0.22 ± 0.20 mm for Fo3 patients and 0.40 ± 0.21 mm for Fo4 patients), with Fo3 group showing less marginal peri-implant bone loss than Fo4 group (estimate of the difference = -0.18 (standard error: 0.06) mm; 95% CI: -0.30 to -0.06; P = 0.005). There were no differences in clinical outcomes between the six operators.. These preliminary results suggest that immediately loaded cross-arch prostheses of both jaws can be supported by only three dental implants at least up to 1 year post-loading, though longer follow-ups are definitively needed.

Topics: Dental Implantation, Endosseous; Dental Implants; Dental Prosthesis, Implant-Supported; Humans; Immediate Dental Implant Loading; Jaw, Edentulous; Mandible; Maxilla; Mouth, Edentulous; Torque

The aim of this study was to evaluate the effect of two different designs, tapered vs cylindrical, on the primary stability of implants placed with an immediate loading protocol in edentulous mandibles to support fixed prostheses within occlusal contacts during the first 48 h.. Tapered and cylindrical implants were placed in a split-mouth study using the same implant protocol in ten patients with edentulous jaws. A total of 20 tapered implants (test group) and 20 cylindrical implants (control group) were placed. All implants were loaded immediately with provisional fixed prostheses during the healing period before the final restoration. The implants were evaluated at the implant placement by analyzing the insertion torque values (ITVs) and the resonance frequency analysis (RFA) and after the healing period of three months, the success of those implants and the marginal bone loss were evaluated.. Two cylindrical implants were mobile within the same patient and no tapered implants failed, resulting in implant survival rates of 90% and 100%, respectively after three months. The ITVs were statistically significantly different (P = 0.0210) for the tapered implants than for the cylindrical implants. However, no statistically significant differences in RFA values were found (P = 0.6063) when comparing the implant designs and the primary stability measured with implant stability quotient (ISQ) values. The control group resulted in a mean bone loss after three months of 0.91 mm while the test group resulted 0.42 mm.. The tapered implant achieved greater primary stability values measured with ITVs and less marginal bone loss than the cylindrical implants.

Topics: Dental Implants; Dental Prosthesis Design; Dental Prosthesis, Implant-Supported; Female; Humans; Immediate Dental Implant Loading; Jaw, Edentulous; Male; Mandible; Prospective Studies; Torque; Treatment Outcome

To compare the outcome of cross-arch prostheses supported either by supershort (5 mm) or long (11.5 mm) implants, placed flapless and immediately restored with metal-resin screw-retained cross-arch prostheses.. Thirty patients with edentulous (or to be rendered edentulous) mandibles and 30 with edentulous maxillas, who had sufficient bone to allow the placement of four and six implants respectively, which were at least 11.5 mm-long, were randomised according to a parallel group design into 2 equal groups, where they received either 5 mm or 11.5 mm-long implants at one centre. Implants with a diameter of 5 mm, were to be placed flapless with an insertion torque of at least 50 Ncm. Mandibles received four implants between the mental foramina. Implants were to be immediately loaded with metal-resin-definitive prostheses on the same day of implant placement. Patients were followed up to 1 year after loading and the outcome measures were: prosthesis and implant failures, complications, and peri-implant marginal bone level changes.. No patients dropped-out. Two prostheses were remade, one on short maxillary implants and one on long mandibular implants. Two 5 mm maxillary implants which did not achieve 50 Ncm torque in soft bone of one patient, but were immediately loaded anyway, failed after 3 weeks compared to one mandibular 11.5 mm-long implant that failed after 60 days. Two complications occurred in each group. There were no statistically significant differences for prosthesis failures, implant failures and complications. Patients with mandibular short implants lost on average 0.08 mm of peri-implant bone at 1 year and patients with long mandibular implants lost 0.51 mm. Patients with short maxillary implants lost on average 0.15 mm of peri-implant bone at 1 year and patients with long maxillary implants lost 0.62 mm. Short implants showed less bone loss when compared to long implants and the differences up to 1 year were statistically significant both in maxillae (mean difference = 0.48 mm, 95% CI 0.22 to 0.73, P = 0.0011) and in mandibles (mean difference = 0.44 mm, 95% CI 0.21 to 0.66, P = 0.0009).. Flapless-placed 5 mm-long implants achieved similar results as 11.5 mm-long implants when supporting immediately loaded cross-arch prostheses both in maxillae and mandibles up to 1 year after loading. These preliminary results must be confirmed by other trials, and 5- to 10-year post-loading data is necessary before making reliable recommendations.

Topics: Adult; Aged; Aged, 80 and over; Alveolar Bone Loss; Bone Density; Dental Implantation, Endosseous; Dental Implants; Dental Prosthesis, Implant-Supported; Dental Restoration Failure; Denture Design; Denture Retention; Female; Follow-Up Studies; Humans; Immediate Dental Implant Loading; Jaw, Edentulous; Male; Mandible; Maxilla; Middle Aged; Osseointegration; Radiography, Bitewing; Torque; Treatment Outcome

To compare the effectiveness of immediately loaded total prostheses supported by implants with a roughened surface versus implants with a machined/turned surface.. Fifty edentulous or to-be-rendered edentulous patients requiring an implant-supported cross-arch prosthesis, were randomised either to receive four to eight implants with a roughened surface (25 patients) or with a machined/turned surface (25 patients). Provisional metal-reinforced acrylic prostheses were delivered 48 h after implant placement. Provisional prostheses were replaced after 4 months, by definitive screw-retained metal-resin cross-arch restorations. Outcome measures were prosthesis and implant failures, any complications and peri-implant marginal bone level changes. Patients were followed 1 year after loading.. One year after loading no patient dropped out. No prosthesis failed, but two machined implants were found to be mobile at definitive impression taking in 1 patient (Fisher's exact test: P = 0.312; difference in proportions = 4%; 95% Cl: -10 to 18). No complications occurred. Both groups presented a significant peri-implant marginal bone loss at 1 year after loading (P < 0.0001), -0.64 ± 0.20 mm for rough implants and -0.68 ± 0.23 mm for turned implants, respectively, with no statistically significant differences between the two groups (P = 0.482; mean difference = 0.04 mm; 95% Cl: -0.17 to 0.25).. Up to 1 year after immediate loading, both implant surfaces provided good and similar results, however, the only two implants which failed early in the same patient had a machined surface. These preliminary results must be confirmed by larger trials with longer follow-ups.

Topics: Acrylic Resins; Adult; Aged; Aged, 80 and over; Alveolar Bone Loss; Dental Alloys; Dental Etching; Dental Implants; Dental Materials; Dental Prosthesis Design; Dental Prosthesis, Implant-Supported; Dental Restoration Failure; Denture Design; Denture, Complete, Immediate; Female; Follow-Up Studies; Humans; Immediate Dental Implant Loading; Jaw, Edentulous; Male; Middle Aged; Pilot Projects; Surface Properties; Torque; Treatment Outcome

To evaluate the outcome of 2 versus 4 implants placed flapless in fully edentulous mandibles and immediately restored with metal-resin screw-retained cross-arch prostheses.. Sixty patients from two different centres were randomised: 30 to the allon- 2 group and 30 to the all-on-4 group according to a parallel group design. To be immediately loaded, implants had to be inserted with a minimum torque of 40 Ncm. Outcome measures were prosthesis and implant failures, complications, and marginal bone level changes.. Flaps were raised in 18 patients. A total of 2 implants in 2 patients did not reach the planned insertion torque and were immediately replaced by larger diameter ones. One year after loading, no drop-out or implant failure occurred. Eight biomechanical complications occurred in the all-on-2 group versus 8 complications in the all-on-4 group. There were no statistically significant differences for complications between groups. There were no statistically significant differences for marginal peri-implant bone levels between the two groups (estimate of the difference = -0.16; 95%CI -0.40 to 0.08; P (ANCOVA) = 0.074), with both groups losing a statistically significant amount of marginal bone (0.74 mm for all-on-2 implants and 0.58 mm for all-on-4 implants). There were statistically significant differences between the two centres, with more bone being lost for the Bologna centre (0.26 mm versus 1.07 mm).. These preliminary results, up to 1 year after loading, suggest that immediately loaded mandibular cross-arch fixed prostheses can be supported by only 2 dental implants. Longer followups (approximately 10 years) are needed to properly evaluate this therapeutic option.

Topics: Adult; Aged; Aged, 80 and over; Alveolar Bone Loss; Biomechanical Phenomena; Dental Alloys; Dental Implant-Abutment Design; Dental Implants; Dental Prosthesis, Implant-Supported; Dental Restoration Failure; Denture Design; Denture Repair; Denture Retention; Denture, Complete, Lower; Female; Follow-Up Studies; Humans; Immediate Dental Implant Loading; Jaw, Edentulous; Male; Mandible; Middle Aged; Pilot Projects; Postoperative Complications; Surgical Flaps; Tooth, Artificial; Torque; Treatment Outcome

The benefit in terms of higher accuracy for full guided implant surgery (template based guided cavity preparation and guided implant insertion) compared with half-guided surgery (template based guided cavity preparation and free-handed, manual implant insertion) has not been proved till now.. A total of 38 identical implants were inserted into five human cadaver jaws, after virtual implant planning with the coDiagnostiX(™) device. All cavities were drilled using templates equipped with tubes for guidance. At random, 19 implants were inserted in a free handed way (half-guided), whereas 19 implants were inserted in a guided way through the templates tubes (full guided). Postoperative cone beam computer tomographies (CBCT) were performed, and based on image fusion the total deviations between the virtual implant positions at the implants base and tip were determined and compared between both implantation modi.. The mean difference in accuracy between both implantation modalities at the implants bases was 0.72 mm (range: 0.16-1.17 mm, SD: 0.45). The mean difference in accuracy between both modalities at the implants tips was 0.46 mm (range: 0.16-1.23 mm. SD: 0.49). Although full guided implantation showed a generally higher accuracy (mean tip: 1.54 mm, range: 0.33-3.64 mm; mean base: 1.52 mm, range: 0.4-3.54 mm) than half-guided implantation (mean tip: 1.84 mm, range: 0.84-3.22 mm; mean base: 1.56 mm, range: 0.49-3.43 mm), the differences were not statistically significant.. The accuracy of half-guided implant surgery is comparable with full guided implant surgery.

Topics: Cadaver; Cone-Beam Computed Tomography; Dental Implantation, Endosseous; Dental Implants; Dental Prosthesis Retention; Equipment Design; Humans; Image Processing, Computer-Assisted; Jaw, Edentulous; Jaw, Edentulous, Partially; Mandible; Osteotomy; Patient Care Planning; Surgery, Computer-Assisted; Torque; User-Computer Interface

Immediate occlusal loading of dental implants in the edentulous mandible has proven to be an effective, reliable, and predictable treatment protocol. However, there is limited long-term data available in the literature, when an electroeroded definitive cast-titanium fixed prosthesis is used for this treatment protocol.. The aim of this study was to evaluate the clinical effectiveness of dental implants (Astra Tech Dental, Mölndal, Sweden) in the edentulous mandible immediately loaded with an electroeroded cast-titanium screw-retained fixed prosthesis.. Forty-five patients received five implants each in the interforaminal area. All the implants were inserted with torque up to 40 Ncm and the distal implants were distally tilted approximately 20 to 30 degrees to minimize the length of posterior cantilevers. Implants were loaded within 48 hours of placement with an acrylic resin-titanium screw-retained prosthesis fabricated by electroerosion.. Two of the 225 inserted implants failed after 3 and 16 months of healing, respectively, with a cumulative survival rate of 99.1% and a prosthetic survival rate of 97.8%.. Immediate loading of tilted dental implants inserted in the edentulous mandible with a screw-retained titanium definitive prosthesis fabricated with electrical discharge machining provide reliable and predictable results.

Topics: Acrylic Resins; Dental Casting Technique; Dental Implants; Dental Marginal Adaptation; Dental Materials; Dental Prosthesis, Implant-Supported; Dental Restoration Failure; Dental Restoration Wear; Denture Design; Denture Retention; Denture, Complete, Lower; Electrochemical Techniques; Female; Follow-Up Studies; Humans; Immediate Dental Implant Loading; Jaw, Edentulous; Male; Mandible; Middle Aged; Osseointegration; Periodontal Index; Retrospective Studies; Survival Analysis; Titanium; Torque; Treatment Outcome

To evaluate the outcome of two freestanding implants immediately loaded retaining an existing mandibular complete denture in elderly edentulous patients up to 1 year after loading.. 42 patients with a mean age of 76.5 years (range 71 to 89) were selected for stabilising their mandibular complete denture with two implants placed mesial to the mandibular canine position bilaterally. Individual ball abutments were connected and torqued at 30 Ncm and the existing complete denture was immediately attached. No postoperative limitations to chewing function were given. The patients were evaluated clinically and radiographically at implant placement and at 6- and 12-month follow-up examinations.. At the 12-month follow-up no implant failed. Peri-implant bone resorption was 0.203 mm (CI 95% 0.322; 0.086) after 6 months and 0.298 mm (CI 95% 0.425; 0.173) after 12 months. Of the 42 cases, 3 had major prosthetic complications and 5 patients required minor extra maintenance appointments.. Within the limits of this study, it can be suggested that the immediate loading of two unsplinted implants retaining the existing complete mandibular denture in elderly patients can result in favourable implant survival and peri-implant bone healing, however larger and longer follow-ups of 5 years or more are needed.

Topics: Aged; Aged, 80 and over; Alveolar Bone Loss; Cohort Studies; Dental Abutments; Dental Implants; Dental Prosthesis, Implant-Supported; Dental Restoration Failure; Denture Bases; Denture Rebasing; Denture Retention; Denture, Complete, Lower; Follow-Up Studies; Humans; Immediate Dental Implant Loading; Jaw, Edentulous; Mandible; Osseointegration; Prospective Studies; Radiography, Panoramic; Survival Analysis; Tomography, X-Ray Computed; Torque; Treatment Outcome

Physical and bioceramic incorporation surface treatments at the nanometer scale showed higher means of bone-to-implant contact (BIC) and torque values compared with surface topography at the micrometer scale; however, the literature concerning the effect of nanometer scale parameters is sparse.. The aim of this study was to evaluate the influence of two different implant surfaces on the percentage bone-to-implant contact (BIC%) and bone osteocyte density in the human posterior maxilla after 2 months of unloaded healing.. The implants utilized presented dual acid-etched (DAE) surface and a bioceramic molecular impregnated treatment (Ossean®, Intra-Lock International, Boca Raton, FL, USA) serving as control and test, respectively. Ten subjects (59 ± 9 years of age) received two implants (one of each surface) during conventional implant surgery in the posterior maxilla. After the non-loaded period of 2 months, the implants and the surrounding tissue were removed by means of a trephine and were non-decalcified processed for ground sectioning and analysis of BIC%, bone density in threaded area (BA%), and osteocyte index (Oi).. Two DAE implants were found to be clinically unstable at time of retrieval. Histometric evaluation showed significantly higher BIC% and Oi for the test compared to the control surface (p < .05), and that BA% was not significantly different between groups. Wilcoxon matched pairs test was used to compare the differences of histomorphometric variables between implant surfaces. The significance test was conducted at a 5% level of significance.. The histological data suggest that the bioceramic molecular impregnated surface-treated implants positively modulated bone healing at early implantation times compared to the DAE surface.

Topics: Acid Etching, Dental; Aged; Bone Density; Calcium Phosphates; Ceramics; Coated Materials, Biocompatible; Dental Implantation, Endosseous; Dental Implants; Dental Prosthesis Design; Female; Humans; Jaw, Edentulous; Male; Maxilla; Middle Aged; Molar; Nanostructures; Osseointegration; Osteocytes; Statistics, Nonparametric; Surface Properties; Torque

The aims of this prospective study were to assess the treatment outcome of immediately loaded full-arch fixed bridges anchored to both tilted and axially placed implants for the rehabilitation of the mandible and to compare the outcome of axial versus tilted implants.. Sixty-two patients (34 women and 28 men) were included in the study. Each patient received a full-arch fixed bridge supported by two axial implants and two distal tilted implants (All-on-Four, Nobel Biocare AB, Göteborg, Sweden). Loading was applied within 48 hours of surgery. Patients were scheduled for follow-up at 6, 12, 18, and 24 months, and annually up to 5 years. At each follow-up, plaque level and bleeding scores were assessed; moreover, patient's satisfaction for aesthetics and function was evaluated by a questionnaire. Radiographic evaluation of marginal bone level change was performed at 1 year.. The overall follow-up range was 6 to 43 months (mean 22.4 months). Forty-four patients were followed for a minimum of 1 year. No implant failures were recorded to date, leading to a cumulative implant survival and prosthesis success rate of 100%. Plaque level and bleeding scores showed progressive decrease over time, parallel to increase of satisfaction for both aesthetics and function. No significant difference in marginal bone loss was found between tilted and axial implants at 1-year evaluation.. The present preliminary data suggest that immediate loading associated with tilted implants could be considered a viable treatment modality for the mandible.

Topics: Adult; Aged; Cohort Studies; Dental Implantation, Endosseous; Dental Implants; Dental Prosthesis Design; Dental Prosthesis, Implant-Supported; Dental Stress Analysis; Denture, Complete, Immediate; Denture, Complete, Lower; Female; Follow-Up Studies; Humans; Jaw, Edentulous; Life Tables; Male; Mandible; Middle Aged; Prospective Studies; Radiography; Time Factors; Torque; Treatment Outcome; Weight-Bearing

A prospective clinical study was conducted to evaluate clinically and radiographically the performance of two implants immediately loaded supporting a ball attachment-retained mandibular overdenture.. Seventeen completely edentulous patients were included in the study. Each patient received two implants inserted after a minimal flap reflection and no vestibular extension in order to reduce the postoperative swelling and facilitate immediate prosthesis connection. After implant placement, a mandibular complete denture was connected to the implants using ball attachments of appropriate height according to the depth of the peri-implant tissue. Patients were asked not to remove the denture for 1 week. No limitations to chewing function were given. At implant placement, the maximum value of insertion torque was recorded. Patients were examined at 1, 2, 4, 12, and 52 weeks postsurgery. At postoperative visit, occlusion was checked and the need for any prosthesis maintenance was recorded. The radiographic bone level (RBL) change was measured on periapical radiographs at baseline and 12 months after loading.. After 12 months of loading, no implant failure was reported and the survival rate was 100%. Average RBL change was 0.7 mm +/- 0.5 mm. Of the 17 cases, two had major prosthetic complications and five patients required minor extra maintenance appointments.. The immediate loading of two implants by means of ball attachment-retained mandibular complete denture may be a predictable treatment option. This clinical approach offers increased stability and comfort, while keeping a high implant success rate.

Topics: Adult; Aged; Aged, 80 and over; Dental Implants; Dental Occlusion; Dental Prosthesis, Implant-Supported; Dental Restoration Failure; Denture Rebasing; Denture Retention; Denture, Complete, Lower; Denture, Overlay; Female; Follow-Up Studies; Humans; Jaw, Edentulous; Male; Mandible; Middle Aged; Osseointegration; Prospective Studies; Radiography; Survival Analysis; Torque; Treatment Outcome

Long healing periods and submerged implant placement are commonly used in the maxilla. This extends the time of oral handicap and makes the use of immediate loading protocols an attractive option. The current clinical literature on direct loading of dental implants in the maxilla is limited.. The purpose of this prospective clinical study was to evaluate the clinical outcome and stability of directly loaded Brånemark System or Replace Select Tapered implants (Nobel Biocare AB, Göteborg, Sweden) after using a modified surgical protocol and inclusion by primary implant stability. In addition, a reference group treated according to a two-stage protocol was used for comparison.. Twenty patients planned for prosthetic rehabilitation with implant-supported bridges in the edentulous maxilla participated in the study group. The final decision on immediate loading was made after implant placement using insertion torque and resonance frequency analysis (RFA) as acceptance criteria. All patients were included, and 123 oxidized implants (TiUnite, Nobel Biocare AB) were placed using a surgical protocol for enhanced primary stability. A screw-retained temporary bridge was delivered within 12 hours and a final bridge within 3 months of implant placement. The patients were monitored through clinical and radiographic follow-up examinations from implant placement to at least 12 months. Marginal bone level was measured at bridge delivery and after 12 months of loading. Additional RFA measurements were made after 6 months of loading. A reference group comprising 20 patients with 120 implants treated according to a two-stage protocol was used for comparison.. One (0.8%) of the 123 implants in the study group failed, and no implant was lost in the reference group. The cumulative survival rates after 12 months of loading were thus 99.2% and 100% for immediate and delayed loading protocols, respectively. The marginal bone resorption was 0.78 (SD 0.9) in the study group and 0.91 (SD 1.04) in the reference group. RFA showed a mean value of 62.9 (SD 4.9) implant stability quotient (ISQ) at placement and 64.5 (SD 4.8) ISQ after 6 months for immediately loaded implants (not significant). The corresponding figures for the reference groups were 61.3 (SD 8.8) ISQ and 62.6 (SD 7.0) ISQ (not significant). There were no statistically significant differences between the groups at any time point.. The use of six to seven implants for immediate loading of a fixed provisional bridge is a viable option for implant treatment of the edentulous maxilla, at least when good primary implant stability can be ensured.

Topics: Aged; Aged, 80 and over; Alveolar Bone Loss; Bone Density; Coated Materials, Biocompatible; Dental Implantation, Endosseous; Dental Implants; Dental Prosthesis Retention; Dental Prosthesis, Implant-Supported; Dental Restoration, Temporary; Dental Stress Analysis; Denture, Complete, Immediate; Female; Humans; Jaw, Edentulous; Male; Maxilla; Middle Aged; Prospective Studies; Titanium; Torque; Vibration

Bone grafts are frequently used to enable the placement of dental implants in atrophied jaws. The biomechanical properties of bone grafts used in one- or two-stage implant procedures (in comparison with the use of nongrafted bone) are not well known.. The purpose of this study was (1) to measure cutting torques during the placement of self-tapping dental implants in nongrafted bone and in bone grafts, either as blocks or in a milled particulate form, in patients undergoing implant treatment in an edentulous maxilla and (2) to identify implants with reduced initial stability and to correlate these findings with a clinical classification of jawbone quality.. The study included 40 consecutive patients with edentulous maxillas, 27 of whom were subjected to bone grafting prior to or in conjunction with implant placement (grafting group) and 13 of whom received implants without grafting (nongrafted group). Grafted bone from the iliac crest bone was used (1) as onlay blocks, (2) as maxillary sinus inlay blocks, or (3) in particulate form in the maxillary sinus. Implants were placed after 6 to 7 months of healing, except in the maxillary sinus inlay blocks, where implants were placed simultaneously. Cutting torque values were obtained from 113 grafted implant sites and from 109 nongrafted implant sites.. Significantly lower cutting torque values were assessed in grafted regions than in nongrafted regions, irrespective of grafting technique. Lower values were also seen for implants placed in block grafts after 6 months when compared to other grafting techniques used. The cutting torque values revealed an inverse linear relation to the Lekholm and Zarb bone quality index.. The cutting torque values correlated well with the Lekholm and Zarb index of bone quality. Significantly lower cutting torque values were seen in grafted bone than in nongrafted bone.

Topics: Alveolar Bone Loss; Alveolar Ridge Augmentation; Biomechanical Phenomena; Bone Density; Bone Transplantation; Dental Implantation, Endosseous; Dental Implants; Dental Prosthesis Retention; Dental Restoration Failure; Follow-Up Studies; Hardness Tests; Humans; Jaw, Edentulous; Maxilla; Maxillary Diseases; Predictive Value of Tests; Stress, Mechanical; Torque; Wound Healing

The interest in the benefits of immediate loading of titanium implants has recently involved fixed prostheses for partially edentulous areas. The advantages of this approach well justify the need for extending the procedure to all regions of the mouth. Current available clinical literature on this subject is incomplete.. The purpose of this study is to investigate the clinical outcome of the immediate loading of Brånemark System implants (Nobel Biocare AB, Gothenburg, Sweden) inserted with enhanced initial stability principally in posterior sites (78%).. The present study was conducted in 26 consecutively treated patients. A total of 50 Brånemark System machined surface implants were placed supporting 30 fixed temporary partial dentures in light occlusion. All implants were followed up for a minimum of 1 year of function. Minimum requirements for immediate loading were proposed. Bone quality and quantity were classified according to Lekholm and Zarb's criteria. Stability of the marginal bone level, both mesial and distal, was measured on the basis of radiographic analysis. Implant survival rate was calculated according to Kaplan-Meier analysis. The peak insertion torque employed during fixture placement was between 40 and 72 Ncm, except in the case of one implant that was lost.. Overall survival rate was 98%. An unpaired t-test revealed bone remodeling conforming to biologic width establishment (p <.005).. Within the limit of this study, immediate loading appears to be a viable procedure in posterior sites and for a growing number of clinical indications. Enhanced implant stability and light occlusion seem to be security factors. In spite of unfavorable conditions such as the presence of quality 4 bone and a lack of splinting, all implants with enhanced primary stability survived.

Topics: Adult; Aged; Alveolar Bone Loss; Dental Implantation, Endosseous; Dental Implants; Dental Prosthesis Design; Dental Prosthesis Retention; Dental Prosthesis, Implant-Supported; Dental Restoration Failure; Dental Restoration, Temporary; Denture, Complete, Immediate; Denture, Partial, Immediate; Female; Humans; Jaw, Edentulous; Male; Middle Aged; Prospective Studies; Radiography; Statistics, Nonparametric; Survival Analysis; Torque

Evaluation of jaw bone quality at implant placement is mainly based on preoperative radiographic assessments and subjective hand registrations during implant site preparation. An objective technique with cutting torque measurements has been introduced, presenting an objective bone quality or bone hardness value of individual implant sites.. The purpose of this study was to evaluate cutting torque measurements during implant placement and to compare these values in different regions in mandibles and maxillae. The objective was to identify implants at risk for failing at implant placement.. Cutting torque measurements were performed during placement of Mk II self-tapping implants (Brånemark System) in 105 patients, comprising 72 edentulous (40 maxillae) and 34 partially edentulous (22 maxillae) jaws. A total of 523 implants were inserted, of which 420 were of the Mk II design and of which 412 were subjected to cutting torque measurements. Statistical analyses were performed by comparing cutting torque values of maxillae and mandibles and of different jaw regions. Cutting torque values were also correlated with radiographically and clinically assessed bone quality scores. Patients were followed clinically for a minimum of 3 years.. A statistically significant difference in cutting torque values of maxillae and mandibles was seen, although not when comparing anterior and posterior regions within the same jaws or of different jaws. Significant correlations were found between values of cutting torque and bone quality. The majority of failures were seen in bone of medium to high density, whereas implants inserted in bone of poor density presented a better outcome, perhaps due to an adapted surgical protocol and an extended healing period. The overall implant survival rate at 3 years was 95%, and when analyzing different jaw categories, survival rates of 92.0% and 99.4% were seen for edentulous maxillae and mandibles, respectively. The corresponding figures for partially edentulous jaws were 95.4% and 97.6%.. It was not possible to identify sites at risk for future implant losses or to determine a lower limit value of cutting torque in order to achieve successful implant integration.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Alveolar Bone Loss; Bone Density; Chi-Square Distribution; Dental Implantation, Endosseous; Dental Implants; Dental Prosthesis Retention; Dental Restoration Failure; Female; Hardness Tests; Humans; Jaw, Edentulous; Life Tables; Male; Middle Aged; Predictive Value of Tests; Prognosis; Prospective Studies; Radiography; Reproducibility of Results; Statistics, Nonparametric; Torque

To evaluate the influence of primary insertion torque (IT) values of narrow dental implants on the peri-implant health, implant stability, immunoinflammatory responses, bone loss, and success and survival rates.. Thirty-one edentulous patients received two narrow implants (2.9x10mm, Facility NeoPoros) to retain mandibular overdentures. The implants were categorized in four groups according to their IT: (G1) IT > 10 Ncm; (G2) IT ≥ 10Ncm and ≤ 30 Ncm; (G3) IT >30Ncm and < 45Ncm; (G4) IT ≥ 45Ncm, and all implants were loaded after 3 months of healing. The following clinical outcomes were evaluated 1, 3, 6, and 12 months after implant insertion: (i) peri-implant tissue health (PH), gingival index (GI), plaque index (PI), calculus presence (CP), probing depth (PD), and bleeding on probing (BOP); (ii) implant stability quotient (ISQ) by resonance frequency analysis; and (iii) IL-1. G1 presented the highest PD at all evaluated periods. G2 presented higher PI at month 6 and 12. G4 showed increased GI at month 3 and 12 and more CP at month 1 (p=.003). G2 and G4 had higher ISQ values over the study period, while those from G1 and G3 presented lower ISQ values. The IL-1. The IT did not influence the clinical outcomes and the peri-implant immunoinflammatory responses and was weakly correlated with the narrow dental implants primary stability. The observed success rates suggest that the ideal IT for atrophic fully edentulous patients may deviate from the standardized IT of 32 Ncm.

Topics: Aged; Aged, 80 and over; Cytokines; Dental Implants; Denture, Overlay; Female; Follow-Up Studies; Humans; Jaw, Edentulous; Kaplan-Meier Estimate; Male; Mandible; Middle Aged; Multilevel Analysis; Torque; Weight-Bearing

The aim of this retrospective clinical study was to evaluate the short-term implant success rate and marginal bone loss in full-arch fixed prosthetic maxillary rehabilitations supported by implants in immediate function with the All-on-4 treatment concept placed with insertion torque of <30N·cm or ≥30N·cm. This study included 83 patients (69 female, 14 male) with 332 implants placed (120 inserted with <30N·cm and 212 inserted with ≥30N·cm) who were treated between January 2010 and March 2013. Outcome measures were implant success and marginal bone loss at 1year of follow-up. Ten patients (12.0%; 13 implants inserted with <30N·cm and 27 implants with ≥30N·cm) were lost to follow-up. The cumulative implant success rate was 97.5% at the patient level, and 98.3% for implants inserted with <30N·cm and 97.5% for implants inserted with ≥30N·cm. The mean±standard deviation marginal bone loss at 1year was 1.14±0.38mm for implants inserted with <30N·cm and 1.39±0.49mm for implants inserted with ≥30N·cm (significant difference; P<0.001, Wilcoxon signed rank test). These results indicate that implants with insertion torques of <30N·cm may render comparable success rates and marginal bone loss at 1year compared to implants inserted with insertion torques of ≥30N·cm.

Topics: Alveolar Bone Loss; Dental Implantation, Endosseous; Dental Implants; Dental Prosthesis, Implant-Supported; Dental Restoration Failure; Denture Design; Denture, Complete, Upper; Female; Humans; Jaw, Edentulous; Male; Maxilla; Middle Aged; Retrospective Studies; Torque; Treatment Outcome

To evaluate the clinical outcome of two implants placed flapless in fully edentulous mandibles and immediately restored with a metal-resin screw-retained cross-arch prostheses 3 years after loading.. Eighty consecutively patients were recruited. Implants for immediate loading had to be inserted with a minimum torque of 80 Ncm. Outcome measures, evaluated by two independent assessors, were: prosthesis and implant failures, complications, marginal bone level changes, implant stability quotient (ISQ) values and patient satisfaction.. Three years after loading, all prostheses were in function although one patient did not come back for the 1- and 3-year follow-ups. Two implants failed early in two patients, but were successfully replaced and their prostheses remade. Twelve complications occurred in 10 patients but were all successfully treated. After 3 years, mean marginal bone loss was 0.43 mm, mean ISQ values decreased from 75.4 to 75.3, and all but four patients were fully satisfied with the therapy. Four patients were partially satisfied because, lacking molars, they could not chew as they wished.. Immediately loaded mandibular cross-arch partial dentures can be supported by only two dental implants up to 3 years. Longer follow-ups (around 10 years) are needed to know the prognosis of this treatment modality.

Topics: Adult; Aged; Aged, 80 and over; Alveolar Bone Loss; Cohort Studies; Dental Implants; Dental Prosthesis Design; Dental Prosthesis, Implant-Supported; Dental Restoration Failure; Denture Design; Denture Retention; Denture, Partial, Fixed; Female; Follow-Up Studies; Humans; Immediate Dental Implant Loading; Jaw, Edentulous; Male; Mandible; Middle Aged; Osseointegration; Patient Satisfaction; Peri-Implantitis; Postoperative Complications; Prospective Studies; Torque; Treatment Outcome

The behavior of fresh-frozen homologous bone (FFB) when used in combination with computer-guided implant surgery has not been investigated yet, and there is a lack of clinical evidence in the literature. The purpose of this retrospective study is to evaluate the implant survival and related fixed full-arch prostheses at the 1- to 5-year follow-up when performed with immediate function using a flapless surgical procedure and computer-aided technology (NobelGuide; Nobel Biocare AB, Goteborg, Sweden) in patients previously treated with FFB grafts. Furthermore, the related values of torque and complications observed were analyzed and discussed. Clinical charts of patients with edentulous arches treated with FFB grafts and NobelGuide system with at least 1 year follow-up were reviewed retrospectively.A total of 65 patients met the criteria of inclusion, receiving a total of 342 implants and 77 full-arch prostheses, with a mean follow-up of 32.87 months (range, 1-5 years). Survival of implants and prostheses was high, reaching 96.5% and 95%, respectively. Factors significantly related to failure of the implants were smoking, position of the implant as last distal abutment, and fracture of basal maxillary bone. Prostheses survival was influenced by bruxism, failure of multiple implants, and torque level of implant equal to 0 at implant insertion. All implants and prostheses failures occurred in the first year. A higher torque level at implant insertion did not correspond to a lower risk of implant failure.Within the limitations of our retrospective study, this treatment modality was predictable with high survival rates and high insertion torque. However, a few implant and prosthetic failures were found, together with several complications.

Topics: Adult; Aged; Allografts; Alveolar Ridge Augmentation; Bone Transplantation; Bruxism; Cohort Studies; Dental Implants; Dental Prosthesis, Implant-Supported; Dental Restoration Failure; Female; Follow-Up Studies; Humans; Immediate Dental Implant Loading; Jaw, Edentulous; Male; Maxillary Fractures; Middle Aged; Retrospective Studies; Smoking; Surgery, Computer-Assisted; Survival Analysis; Torque

This prospective study was performed to evaluate the outcomes of XiVE® S plus implants (Dentsply Friadent, Mannheim, Germany) following conventional restoration with bar structures and overdentures in the edentulous mandible.. A total of 39 patients were treated with four interforaminal implants (n = 156) splinted by a Dolder bar. Overdentures were attached to the bars after 3 months of healing. As primary outcome measures, clinical and radiological parameters were evaluated at the time of implant placement (baseline) and once a year (1, 2, 3, 4, 5 years) after functional loading. Secondary outcome measures included (i) primary stability and surgical complications, as well as (ii) Periotest® (Medizintechnik Gulden, Modautal, Germany) values, implant survival, and prosthetic complications at baseline and follow-up.. A total of 156 implants were placed. The vast majority (n = 149) were tightened to >30 Ncm, while torques in the range of 20-30 Ncm were obtained in the remaining cases (n = 7). Mean crestal bone levels around the implants were 0.41 mm at baseline and 1.04/1.20/1.34/1.45/1.44 mm after 1/2/3/4/5 years respectively. The mean values of the plaque, calculus, bleeding, and mucosal indices remained low throughout this period. The reported follow-up periods involved one implant loss after 3 months (survival rate: 99.4%) and one implant failure after 4 years (success rate: 98.4%). Prosthetic complications included factures of bars (n = 3) and denture teeth (n = 7). Prosthetic survival was 100%.. Dolder bars to restore oral implants in the edentulous mandible appear to offer a high rate of implant survival, good stability of the peri-implant tissue, and a low rate of prosthetic complications.

Topics: Adult; Aged; Alveolar Process; Dental Calculus; Dental Implants; Dental Plaque Index; Dental Prosthesis, Implant-Supported; Dental Restoration Failure; Denture Design; Denture Retention; Denture, Complete, Lower; Denture, Overlay; Female; Follow-Up Studies; Humans; Jaw, Edentulous; Male; Mandible; Middle Aged; Osseointegration; Periodontal Index; Prospective Studies; Radiography; Survival Analysis; Tooth, Artificial; Torque; Treatment Outcome

Computerized tomographs (CTs) are commonly used for presurgical planning of dental implant placement. It is possible that implant stability can be predicted based on quantitative measurements of bone density at planned implants sites with the use of diagnostic software.. The aim was to evaluate if there is a correlation between bone density measurements in specific implant positions in preoperative CTs and insertion torque (IT) and implant stability measurements when placing the implants.. The study comprised of four patients in whom presurgical CTs had been used to plan implant treatment. A total of 26 implants (Neoss, Harrogate, UK) were placed in the totally edentulous maxilla (n=3) or mandible (n=1). IT was measured during implant insertion and the torque/time curves examined for mean IT (newton-centimeters) over the total curve. The stability of implants was measured with resonance frequency analysis. The positions of the implants were extracted from a postoperative CT to the preoperative one. Bone density was measured with a dedicated software (3Diagnosys™ 3.0, 3Diemme, Cantù, Italy) in virtual hollow probes, indicating the bone volume within 1mm from each implant surface. The Spearman Rank correlation test was used to find possible correlations.. Statistically significant correlations were found between mean bone density, mean IT, and implant stability measurements.. This pilot study showed a correlation between bone density, as measured in Hounsfield units in preoperative CTs, and IT and implant stability measurements at the surgical placement of the implants. The findings support the idea that integration of bone density measurements in implant probes in preoperative CTs using treatment-planning software may be a useful feature to predict implant stability and to avoid failures.

Topics: Aged; Bone Density; Dental Implants; Dental Prosthesis Retention; Female; Forecasting; Humans; Image Processing, Computer-Assisted; Jaw, Edentulous; Male; Mandible; Maxilla; Middle Aged; Patient Care Planning; Pilot Projects; Software; Tomography, X-Ray Computed; Torque; User-Computer Interface; Vibration

The aims of this study were to evaluate a surgical/prosthetic protocol for the immediate rehabilitation of the augmented edentulous maxilla, and to compare the outcomes of implants placed in grafted (test group) versus native (control group) sites in the same patients.. Twenty patients were included in the study. Each patient was treated with a bilateral sinus augmentation procedure using a 50:50 composite graft of autogenous mandibular bone and bovine hydroxyapatite. Four to 5 months later, 155 implants (90 test and 65 control) were placed and restored with screw-retained fixed definitive prostheses supported by titanium frameworks within 1 week. All patients were followed for 1 year. Implant stability quotient (ISQ) measurements and radiographic evaluation of the marginal bone resorption (MBR) were performed.. Two test implants failed in two patients, giving a cumulative 1-year success rate of 98.7%; the prostheses success rate was 100%. Insertion torque and ISQ values for test implants were significantly lower than those for control implants (unpaired t-test, p < .0001). The mean MBR around control and test implants at the 1-year evaluation were similar (0.47 ± 0.25 mm and 0.43 ± 0.21 mm, respectively).. The combination of implants placed in sinus-grafted and native sites can be immediately loaded with a fixed full-arch prosthesis and yield short-term successful outcomes.

Topics: Animals; Bone Substitutes; Bone Transplantation; Cattle; Dental Materials; Dental Prosthesis, Implant-Supported; Dental Restoration Failure; Denture Bases; Denture Design; Denture Retention; Denture, Complete, Upper; Durapatite; Follow-Up Studies; Humans; Immediate Dental Implant Loading; Jaw, Edentulous; Maxilla; Osseointegration; Patient Satisfaction; Peri-Implantitis; Pilot Projects; Postoperative Complications; Radiography, Dental, Digital; Sinus Floor Augmentation; Titanium; Torque; Transplantation, Autologous; Treatment Outcome

To evaluate the clinical outcome of 2 implants placed flapless in fully edentulous mandibles and immediately restored with a metal-resin screw-retained cross-arch prosthesis 1 year after loading.. Eighty consecutive patients were recruited. To be immediately loaded, implants had to be inserted with a minimum torque of 80 Ncm. Outcome measures, evaluated by two independent assessors, were prosthesis and implant failures, complications, marginal bone level changes, implant stability quotient (ISQ) values and patient satisfaction.. Flaps were raised in 7 patients. Twelve implants in 7 patients did not reach the planned insertion torque. Four implants in 3 patients were immediately replaced by larger diameter implants and achieved the desired torque, whereas the remaining implants were immediately loaded anyway. Two implants failed early in 2 patients, but were successfully replaced and their prostheses remade. One month after loading, 72 (90%) patients declared to be completely satisfied with the therapy, 7 (9%) partially satisfied and 1 (1%) unsatisfied. One year after loading, all prostheses were in function, though one patient did not attend the 1-year control. Eight (10%) complications occurred, all successfully treated. After 1 year, the mean marginal bone loss was 0.3 mm and mean ISQ values decreased from 75.4 to 72.4.. These short-term results at 1 year after loading suggest that immediately loaded mandibular cross-arch fixed prostheses can be supported by only 2 dental implants. Longer follow-ups (around 10 years) are needed to know the prognosis of this treatment modality.

Topics: Adult; Aged; Aged, 80 and over; Alveolar Bone Loss; Cohort Studies; Dental Implants; Dental Prosthesis Retention; Dental Prosthesis, Implant-Supported; Dental Restoration Failure; Denture Design; Denture Retention; Denture, Complete, Lower; Female; Follow-Up Studies; Humans; Immediate Dental Implant Loading; Jaw, Edentulous; Male; Mandible; Middle Aged; Osseointegration; Patient Satisfaction; Postoperative Complications; Prospective Studies; Torque; Treatment Outcome

To retrospectively evaluate the outcome of immediately loaded cross-arch fixed dental prostheses 6 months after loading. A second aim was to compare survival rates of implants placed in healed versus fresh extraction sites.. In total, 113 consecutive patients about to have their maxillae rendered fully edentulous (mean extractions per patient: 6.7 teeth) received four to eight implants each (total number = 675) which were immediately placed in healed sites (323 implants, 47.9%) or fresh sockets (352 implants, 52.1%). Immediate loading of provisional prostheses was performed and all patients were followed up for 6 months. The success criteria included prosthesis success, assessment of individual implant stability and complications.. No patients dropped out and all 113 patients received definitive fixed prostheses after 6 months of loading. The overall implant survival rate after 6 months was 99.1%. Six implants were lost in 6 patients (5.3%). Five of them were inserted in fresh extraction sockets (1.4%) and one in a healed site (0.3%). No significant difference (P = 0.1621) was found for implants placed in healed sites versus fresh extraction sites. Ten patients had fractures of the provisional prostheses as complications.. Immediate implant placement and loading resulted in high implant as well as prosthetic survival rates. Placement in healed or fresh extraction bone sites may not influence implant survival.

Topics: Adult; Aged; Aged, 80 and over; Cohort Studies; Dental Implant-Abutment Design; Dental Implants; Dental Prosthesis Retention; Dental Prosthesis, Implant-Supported; Dental Restoration Failure; Denture Design; Denture, Complete, Upper; Female; Follow-Up Studies; Humans; Immediate Dental Implant Loading; Jaw, Edentulous; Male; Maxilla; Middle Aged; Retrospective Studies; Survival Analysis; Tooth Extraction; Tooth Socket; Torque; Treatment Outcome

To evaluate the outcome of treatment in the rehabilitation of edentulous jaws with early loaded full-arch screw-retained prostheses after up to 4 years of function.. Patients with completely edentulous maxillae and/or mandibles, or presenting natural teeth with a poor or hopeless prognosis, received 6 implants each in the mandible and/or 8 in the upper jaw. All patients received a full-arch prosthetic reconstruction.. A total of 19 patients were treated with a total of 164 implants. One hundred nineteen implants were placed immediately after tooth extraction, and 45 implants were placed in healed sites. Overall, 8 implants failed, leading to a 4-year cumulative survival rate of 95.1%.. The rehabilitation of the edentulous maxilla and mandible with an early loaded prosthesis represents a viable alternative treatment to classic loading protocols.

Topics: Adult; Aged; Dental Implant-Abutment Design; Dental Implants; Dental Prosthesis Design; Dental Prosthesis, Implant-Supported; Dental Restoration Failure; Denture Design; Denture Retention; Denture, Complete; Female; Follow-Up Studies; Humans; Immediate Dental Implant Loading; Jaw, Edentulous; Male; Mandible; Maxilla; Middle Aged; Survival Analysis; Tooth Extraction; Tooth Socket; Torque; Treatment Outcome

Chemically modified surfaces were introduced during the last decade to improve indications for implant treatment. The fluoride-modified implant (Osseospeed(®)) was launched in 2004 and clinical studies suggest a more rapid bone formation and stronger bone to implant contact. However, limited clinical data are available on marginal bone loss and the outcome after >1 year under immediate loading conditions is not fully understood. Hence, the purpose of this prospective study was to present implant survival and marginal bone level data when fluoride-modified implants are supporting a fully functional rehabilitation from the day after surgery in the completely edentulous mandible.. Twenty-five patients, completely edentulous in the mandible, were consecutively treated with five fluoride-modified implants that were functionally loaded with a provisional screw retained restoration. Marginal bone loss was measured from day of surgery to 3, 6, 12 and 24 months. Implants were considered successful after 24 months if radiographic bone loss did not exceed 1 mm and no pain or mobility was caused under a torque of 20 N cm. Statistical analysis was carried out on both patient and implant levels.. All implants survived and mean bone loss on implant level after 3, 6, 12 and 24 months was 0.14, 0.13, 0.11 and 0.11 mm, respectively. Bone loss was only statistically significant between baseline and 3 months (P<0.001) and remained unchanged afterward. None of the implants lost >1 mm of bone after 2 years. On the patient level, the mean bone loss after 2 years was 0.12 mm (SD 0.14; range -0.06 to 0.55) with probing pocket depth 2.45 mm (SD 0.43; range 1.3-3.1) and bleeding index 0.55% (SD 0.34; range 0-1).. Immediate loading of fluoride-modified implants is a predictable treatment yielding a high survival and success rate after 2 years.

Topics: Adult; Aged; Dental Implantation, Endosseous; Dental Implants; Dental Prosthesis Design; Dental Prosthesis Retention; Dental Stress Analysis; Female; Fluorides; Humans; Jaw, Edentulous; Male; Mandible; Middle Aged; Prospective Studies; Radiography, Panoramic; Surface Properties; Torque; Treatment Outcome

This study aimed to evaluate the long-term prognosis of immediately loaded fixed full prostheses for the treatment of edentulous patients with extreme bone atrophy in the posterior mandibular region.. Twenty-four edentulous patients with atrophic posterior mandibles were treated by means of a complete prosthesis sustained by both axial and tilted fixtures. The insertion of tilted implants was carefully planned by means of computed tomography scan analysis and measuring width and height of residual bone. Implant type, length, and diameter were chosen, as well as implant angulation, according to the All-on-Four protocol and avoiding the course of the mandibular nerve. The prosthesis was delivered no later than 2 days after implant surgery. Implant survival and prosthesis success were assessed clinically and radiographically up to 42 months of follow-up. Measurement of peri-implant bone loss was based on periapical radiographs after 12 months of loading.. All implants survived and all prostheses were successful at the time of this study reporting. The mean follow-up was 30.1 months with a range of 14 to 44 months. The average peri-implant bone loss was 0.85 mm after 12 months (0.8 mm for tilted implants and 0.9 mm for axial implants). No significant difference in marginal bone loss was observed between axial and tilted implants.. The immediate rehabilitation of patients with extreme atrophic mandibles can be successful with careful planning and particular attention during the surgical placement of the implants, as shown by the excellent outcomes of the present study.

Topics: Adult; Aged; Alveolar Bone Loss; Atrophy; Bone Density; Dental Abutments; Dental Implantation, Endosseous; Dental Implants; Dental Prosthesis Design; Dental Prosthesis, Implant-Supported; Denture Design; Denture, Complete, Immediate; Denture, Complete, Lower; Female; Follow-Up Studies; Humans; Jaw, Edentulous; Longitudinal Studies; Male; Mandible; Middle Aged; Patient Satisfaction; Prognosis; Radiography; Survival Analysis; Torque; Treatment Outcome

The objective of this retrospective study was to evaluate the overall success of immediately loaded implants in the mandible. This report focuses on immediately loaded anterior and posterior mandibular implants.. A total of 979 patients received 2,904 mandibular dental implants placed from January 2007 to December 2008. One hundred sixty-one of the implants were placed anterior to the mental foramen, and 95 were placed posterior to the mental foramen. All immediately loaded implants were torque tested to 35 N-cm. All were provisionally restored the day of insertion.. A total of 256 immediately loaded mandibular dental implants were placed in a 2-year period. Of the 256 immediately loaded implants, 252 integrated and were restored and 4 failed. Of the 4 failed implants, 3 were in the anterior mandible and the fourth was in the posterior mandible. All 4 were replaced, integrated, and have been restored. The survival rate for immediately loaded implants in the anterior mandible was 99.4%, and the survival rate in the posterior mandible was 97%.. Immediately loaded implants have predictable clinical success in the anterior and posterior mandible.

Topics: Dental Abutments; Dental Implants; Dental Occlusion; Dental Prosthesis Design; Dental Prosthesis Retention; Dental Prosthesis, Implant-Supported; Dental Restoration Failure; Follow-Up Studies; Humans; Jaw, Edentulous; Jaw, Edentulous, Partially; Mandible; Osseointegration; Retrospective Studies; Survival Analysis; Time Factors; Torque; Treatment Outcome

The purpose of this study was to qualify and quantify bone strains around immediately-loaded implants supporting mandibular fixed prostheses with regard to number of implant support.. Linear strain gauges were bonded on the labial bone of 5 Straumann dental implants placed in the mandibular symphysis region of 2 completely edentulous mandibles of fresh human cadavers. Installation torque value of each implant was measured by a custom-made torque wrench and resonance frequency analyses were undertaken. A one-piece full-arch fixed prosthesis was fabricated for each cadaver and 2 miniature load cells were integrated in the cantilever region of the prostheses for controlled loading experiments. 5-, 4-, and 3-implant support designs were consecutively tested. Strain measurements were performed at a sample rate of 10 KHz and under a maximum load of 100 N, simultaneously monitored from a computer connected to data acquisition system.. The installation torque values and implant stability quotient values of the implants ranged between 42.12 to 145.67 N cm and 61 to 80, respectively. Between-group comparisons revealed that the highest strain magnitudes were recorded for the 3-implant design followed by the 4- and 5-implant designs, although there was a tendency toward similar load partitioning between 4- and 5-implant designs (P < 0.05).. Bone strains around 3-implant supported mandibular fixed prostheses is significantly higher than those around 4- and 5-implant designs, and this may lead to failure of supporting implants. Four- and 5-implant designs might have similar clinical outcome.

Topics: Aged; Alveolar Process; Cadaver; Dental Implantation, Endosseous; Dental Prosthesis Retention; Dental Prosthesis, Implant-Supported; Dental Stress Analysis; Denture, Complete, Immediate; Denture, Complete, Lower; Humans; Jaw, Edentulous; Male; Middle Aged; Time Factors; Torque

Surgical guides may interfere with effective use of surgical instrumentation during implant placement in the posterior segments where interocclusal distance may be limited.. The purpose of this study was to measure and compare the accuracy of posterior implant placement using 3 precision surgical guides with varying occlusogingival heights, and to evaluate the difference in accuracy of implant placement through precision guides as compared to freehand placement.. Three groups of surgical guides were fabricated with occlusogingival heights of 4, 6, and 8 mm, respectively. A jig was fabricated to allow for accurate positioning in bone substitute blocks. Ninety implants were placed in the mandibular first molar site on a manikin. Thirty implants (Astra Tech AB) were placed for each group, with 15 through the guide and 15 freehand. Distances between a reference implant and each placed implant were measured at both implant and abutment levels using a coordinate measuring machine. Apex position and angular discrepancy were calculated using the coordinates of the centers of the implant platform and of the occlusal aspect of the abutment. Data was assessed using 2-way ANOVA (alpha=.05).. Two-way ANOVA demonstrated that guide height did not significantly affect the accuracy of the implant position. The distance from the reference point to the point of measurement was significantly smaller for placement through the guide compared to freehand placement at both implant (P<.001) and abutment levels (P<.001). The angular discrepancy was also significantly smaller for placement through the guide (P<.001).. Precision surgical guides with 4-mm occlusogingival height allow placement as accurate as precision guides with 8-mm height. Placement through the guide reproduced the target position more accurately than freehand insertion.

Topics: Computer-Aided Design; Dental Implantation, Endosseous; Equipment Design; Humans; Jaw, Edentulous; Mandible; Manikins; Models, Anatomic; Models, Dental; Radiography; Surgery, Computer-Assisted; Torque; User-Computer Interface; Vertical Dimension

The quality of bone is an important factor in the successful implant treatment, and it is evident that higher implant failure is more likely in poor quality of bone. The primary stability of oral implants related to resistance to micromotion during healing is influenced by bone quality, surgical technique, and implant design.. The aims of this biomechanical study were to explore the effect of bone quality on initial intraosseous stability of implants, and to determine the correlations between the bone quality and implant stability parameters.. Twenty-four implants (Neoss Ltd., Mölnlycke, Sweden) were placed into anterior and posterior regions of three human cadaver mandibles. The bone densities of implant recipient sites were preoperatively determined using computerized tomography (CT) in Hounsfield unit (HU). The maximum insertion torque values were recorded, and primary implant stability measurements were noninvasively performed by means of resonance frequency analysis (RFA).. The bone density values ranged from -267 HU to 553 HU. It was found that mean bone density, insertion torque, and RFA values were 113 +/- 270 HU, 41.9 +/- 5 Ncm, and 70 +/- 7 implant stability quotient (ISQ), respectively. Statistically significant correlations were found between bone density and insertion torque values (r = 0.690, p < .001); bone density and ISQ values (r = 0.557, p < .05); and insertion torque and ISQ values (r = 0.853, p < .001).. CT is a useful tool to assess bone quantity and quality in implant recipient sites, and bone density has a prevailing effect on implant stability at placement.

Topics: Biomechanical Phenomena; Bone Density; Cadaver; Dental Arch; Dental Implantation, Endosseous; Dental Implants; Dental Prosthesis Design; Humans; Jaw, Edentulous; Mandible; Stress, Mechanical; Tomography, X-Ray Computed; Torque; Transducers; Vibration

The aim of this case series was to evaluate the Procera Software v1.6 and the surgical templates for flapless implant placement and immediate loading in atrophic fully edentulous maxillae.. The Procera Software was used to plan the exact position of the implants, and surgical templates were made to guide flapless implant placement. To allow for immediate loading, implants had to be placed with an insertion torque > 30 Ncm. Provisional cross-arch prostheses, produced before surgery using the software planning, were delivered immediately after implant placement, and replaced by final restorations after 6 months. Outcome measures were: prosthetic and implant failures, complications, post-operative pain and swelling, consumption of analgesics, and patient satisfaction. The followup stopped at 8 months post-loading.. Thirteen consecutive patients with atrophic maxillae were treated with 89 implants (6 to 8 implants per patient). Two flaps had to be elevated in two patients. One template fractured during surgery. Three implants in two patients were not loaded immediately. In four patients, impressions had to be taken to fit the provisional prostheses onto the implants. Five implants failed in four patients. One patient dropped out, due to financial reasons, with the provisional prosthesis still in function. Eight months after loading, all prostheses were successful and 11 out of 12 patients reported their quality of life and lifestyle had improved.. This software-based treatment planning may be useful in planning and treating challenging cases such as flapless implant placement and immediate loading of maxillary cross-arch bridges, but a learning curve is necessary.

Topics: Adult; Aged; Aged, 80 and over; Analgesics; Computer-Aided Design; Dental Implantation, Endosseous; Dental Implants; Dental Restoration Failure; Denture Design; Edema; Female; Follow-Up Studies; Humans; Jaw, Edentulous; Life Style; Male; Maxilla; Middle Aged; Pain, Postoperative; Patient Care Planning; Patient Satisfaction; Pilot Projects; Postoperative Complications; Prospective Studies; Quality of Life; Surgery, Computer-Assisted; Torque; Treatment Outcome

The primary stability of dental implants associated with resistance to micromotion during healing is affected by surgical technique and implant design, which are important especially in the soft bone, where implant failures are more likely.. This study was designed to compare the parameters associated with implant insertion using two different methods of enhancing implant primary stability and to identify any relationship between these parameters at implant insertion.. A total of 60 implants were placed in the maxillary posterior regions of 22 patients. The bone densities at the implant sites were recorded using a computerized tomography machine in Hounsfield unit (HU). The maximum insertion torque data were recorded with the Osseocare (Nobel Biocare AB, Göteborg, Sweden) equipment, while resonance frequency analysis (RFA) measurements were taken using an Osstell (Integration Diagnostics AB, Göteborg, Sweden) machine at implant surgery. Comparisons including HU, Ncm, and implant stability quotient were made between two control groups (C1 and C2), and corresponding four test groups (T1-T4) using thinner drills to enhance primary implant stability.. Two implants were lost, meaning an overall implant survival rate of 96.6% after 3 +/- 1 years. When compared to control groups, significantly higher mean maximum insertion torque and RFA values were found for corresponding test groups. In addition, strong correlations were observed between the bone density and insertion torque, and implant stability values at implant placement.. The results of this study suggest that using thinner drills for implant placement in the maxillary posterior region where bone quality is poor may improve the primary implant stability, which helps clinicians to obtain higher implant survival rates.

Topics: Bone Density; Dental Implantation, Endosseous; Dental Implants; Dental Prosthesis Retention; Dental Prosthesis, Implant-Supported; Dental Restoration Failure; Dental Stress Analysis; Denture, Partial, Fixed; Female; Follow-Up Studies; Humans; Jaw, Edentulous; Male; Maxilla; Middle Aged; Radiography; Torque; Vibration

Immediate occlusal loading of dental implants in the edentulous mandible has proven to be an effective, reliable, and predictable procedure. There is little long-term data available on similar treatments in the edentulous maxilla.. The purpose of this study was to evaluate the 12-month implant survival after immediate loading of 4 to 6 implants with fixed screw-retained prostheses in edentulous maxillae.. Twenty-one patients, edentulous or with remaining teeth to be extracted in the maxilla, received 4 to 6 implants (n=111). The patients were restored with screw-retained fixed provisional prostheses supported by palladium-alloy frameworks within 24 hours after surgery. Insertion torques for implants were at least 40 Ncm. Implants, grouped as tapered or cylindrical screws, were placed in healed bone or extraction sockets. Implants were also classified as either vertical or off-angle. Definitive prostheses were placed after a mean healing time of 18 weeks. Radiographic examinations were made at the time of placement of provisional prostheses and 12 months later. Between-groups bone resorption was compared using 2-way ANOVA (alpha=.05).. The mean follow-up time for all of the patients was 20 months (range, 13 to 28 months). The cumulative implant survival rate at the 12-month follow-up visits (after surgery) was 92.8%; the prostheses survival rate was 100%. No significant differences were found between the survival of tapered or cylindrical screw-type implants placed in postextraction sockets versus those in healed edentulous sites or between vertical and off-angle placed implants. Eight implants failed during the first 3 months, 5 of which were the most distal implants. The mean reduction in marginal bone height over the 12-month observation period was 0.84 mm (CI 95%; 0.68-0.99 mm).. In this study with 12-month follow-up, 4 to 6 implants were sufficient to successfully support fixed implant screw-retained prostheses in the edentulous maxillae of 21 patients.

Topics: Bone Resorption; Dental Abutments; Dental Alloys; Dental Implantation, Endosseous; Dental Implants; Dental Prosthesis Design; Dental Prosthesis, Implant-Supported; Dental Restoration Failure; Denture Design; Denture, Complete, Immediate; Denture, Complete, Upper; Female; Follow-Up Studies; Humans; Jaw, Edentulous; Male; Maxilla; Middle Aged; Palladium; Pilot Projects; Survival Analysis; Tooth Socket; Torque

Implants that rotate during abutment screw tightening may not necessarily constitute implant failure. This prospective study was designed to determine to what degree integrated implants could gain a state of reintegration after intentional countertorque to liberation from the bone.. There were 11 patients with fully edentulous mandibles restored with 2 "clinical" implants (3.75 x 10 mm) placed in the canine sites and an additional nonused "test" implant (3.75 x 10 mm) placed at the symphysis of the anterior mandible. At second-stage surgery, the test implant was countertorqued (T1) using a torque-metering wrench until it detached from the bone. The implant was returned to its original position and allowed to heal for a period until a second countertorque test (T2) was performed. In group A, patients (n = 5) received the countertorque T1 at 3 months and T2 at 5 months. In group B (n = 6) T1 was at 1.5 months, and T2 was at 3.5 months. After completion of T2, the group A test implants were removed with a 5-mm trephine for histologic examination.. For both groups, peak forces, all higher than 37.4 Ncm at T1, indicate that all implants were integrated. At T2, torque values were higher than T1 values for most of the test implants. The clinical implants were restored with "patrix" abutments and an overdenture. Histology staining showed distinction between old and new bone, which formed during the remodeling process.. The increase in peak forces needed to detach implants at T2 may be explained by bone-to-bone healing or the additional bone contact promoted by bleeding that occurred during the T1 procedure.. The results suggest that all implants were reintegrated after being intentionally countertorqued to liberation and resumed healing in the original osteotomy position.

Topics: Aged; Dental Implantation, Endosseous; Dental Implants; Female; Humans; Jaw, Edentulous; Male; Mandible; Middle Aged; Prospective Studies; Rotation; Torque

The aim of the present study was to determine the correlation between the primary stability of dental implants placed in edentulous maxillae and mandibles, the bone mineral density and different histomorphometric parameters. After assessing the bone mineral density of the implant sites by computed tomography, 48 stepped cylinder screw implants were installed in four unfixed human maxillae and mandibles of recently deceased people who had bequeathed their bodies to the Anatomic Institute I of the University of Erlangen-Nuremberg for medical-scientific research. Peak insertion torque, Periotest values and resonance frequency analysis were assessed. Subsequently, histologic specimens were prepared, and bone-to-implant contact, the trabecular bone pattern factor (TBPf), the density of trabecular bone (BV/TV) and the height of the cortical passage of the implants were determined. The correlation between the different parameters was calculated statistically. The mean resonance frequency analysis values (maxilla 6130.4+/-363.2 Hz, mandible 6424.5+/-236.2 Hz) did not correlate with the Periotest measurements (maxilla 13.1+/-7.2, mandible -7.9+/-2.1) and peak insertion torque values (maxilla 23.8+/-2.2 N cm, mandible 45.0+/-7.9 N cm) (P=0.280 and 0.193, respectively). Again, no correlations could be found between the resonance frequency analysis, the bone mineral density (maxilla 259.2+/-124.8 mg/cm(3), mandible 349.8+/-113.3 mg/cm3), BV/TV (maxilla 19.7+/-8.8%, mandible 34.3+/-6.0%) and the TBPf (maxilla 2.39+/-1.46 mm-1, mandible -0.84+/-3.27 mm-1) (P=0.140 and 0.602, respectively). However, the resonance frequency analysis values did correlate with bone-to-implant contact of the oral aspect of the specimens (maxilla 12.6+/-6.0%, mandible 35.1+/-5.1%) and with the height of the crestal cortical bone penetrated by the implants in the oral aspect of the implant sites (maxilla 2.1+/-0.7 mm, mandible 5.1+/-3.7 mm) (P=0.024 and 0.002, respectively). The Periotest values showed a correlation with the height of the crestal cortical bone penetrated by the implants in the buccal aspect of the implant sites (maxilla 2.5+/-1.2 mm, mandible 5.4+/-1.2 mm) (P=0.015). The resonance frequency analysis revealed more correlations to the histomorphometric parameters than the Periotest measurements. However, it seems that the noninvasive determination of implant stability has to be improved in order to give a more comprehensive prediction of the bone characteristics of the implant

Topics: Aged; Aged, 80 and over; Analysis of Variance; Bone Density; Dental Implantation, Endosseous; Dental Implants; Dental Prosthesis Retention; Dental Restoration Failure; Humans; Jaw, Edentulous; Linear Models; Male; Mandible; Maxilla; Tomography, X-Ray Computed; Torque; Vibration

The aim of this study was to establish a correlation between bone mineral density measured preoperatively with dental computed tomography (CT), and insertion torque of screw-shaped dental implants.. In eight human mandibles obtained postmortem, bone mineral density (BMD) was measured with dental quantitative CT (DQCT) and correlated with insertion torque values at 45 implant sites during insertion of screw-shaped dental implants (Brånemark System MKIII, Nobel Biocare, AB, Göteborg, Sweden).. A significant correlation (r=0.86, P<0.001) between BMD and torque values was observed, indicating that local BMD at a specific implant position is related to the supportive capacity of the jawbone. BMD exhibited no correlation with bone height or position.. The noninvasive assessment of BMD using a DQCT scan employing a low-dose protocol may be used to estimate expected primary stability depending on BMD, implant type and preparation procedure. These data may therefore help the surgeon to select the optimum implant position, implant type and operation technique.

Topics: Absorptiometry, Photon; Bone Density; Dental Implantation, Endosseous; Dental Implants; Dental Prosthesis Retention; Dental Stress Analysis; Humans; Jaw, Edentulous; Mandible; Patient Care Planning; Prognosis; Regression Analysis; Tomography, X-Ray Computed; Torque

A number of different dental implant designs are currently in clinical use. A successful outcome of implant placement is thought, at least in part, to be due to the primary stability of an implant after placement. Few data are available for comparing the primary stability characteristics of different implant designs.. This investigation compared the primary stability of five types of endosseous dental implant of varying geometry and surface topography.. Comparison was made between a standard threaded commercially pure titanium implant (Nobel Biocare AB, Göteborg, Sweden), the Mark II self-tapping implant (Nobel Biocare AB, Göteborg, Sweden), the Mark IV tapered self-tapping implant (Nobel Biocare AB, Göteborg, Sweden), the Astra Tioblast (AstraTech AB, Mölndahl, Sweden), and the 3i Osseotite (3I [Implant Innovations Incorporated], Palm Beach, Florida, USA). Fifty-two fixtures were placed in the maxillary bone of nine unembalmed human cadavers. Implant stability as a function of peak insertion torque and resonance frequency values was recorded for each fixture site after placement. Removal torque was also measured 1-hour postinsertion. Assessment of bone quality at each site was made.. All of the implants tested demonstrated good primary stability in type 2 and 3 bone. The Standard, Mark II, Osseotite, and Tioblast were less stable when placed into bone type 4. The Mark IV implants appeared to maintain a high primary stability even in Type 4 bone.. When looking across all bone qualities, the Mark IV implant develops a significantly higher insertion torque than the Standard, Mark II, and Osseotite implant types, and a significantly higher resonance frequency value than the Standard implant, indicating a higher interfacial stiffness at the implant-bone interface.

Topics: Aged; Analysis of Variance; Bone Density; Cadaver; Dental Implantation, Endosseous; Dental Implants; Dental Prosthesis Design; Dental Prosthesis Retention; Elasticity; Electrodiagnosis; Female; Humans; Jaw, Edentulous; Male; Maxilla; Statistics as Topic; Surface Properties; Titanium; Torque; Transducers

Oral implant treatment ad modum Brånemark was undertaken in nine patients with edentulous maxillae. Cutting torque measurements and resonance frequency analyses (RFA) were conducted at implant placement and the corresponding values were subjected to correlation analyses. The implants were also evaluated with RFA at abutment connection and at one-year follow-up in order to identify possible changes in implant stability. A total of 61 implants were inserted, of which 49 were of the Mk II self-tapping type. Two implants were lost during the study period. The cumulative torque was presented as a mean value for the upper/crestal, the middle and the lower/apical third of the implant site respectively, as well as an overall value for the whole site. The highest correlation (r = 0.84, P<0.05) was found when comparing the mean torque values of the upper/crestal portion with the resonance frequency values at implant placement. The Mk II implant sites were divided into three groups based on the values of the cutting torque, i.e. soft (group 1), medium (group 2) and dense bone (group 3). The mean value of each group was plotted against the corresponding mean value of resonance frequency measured at implant insertion. Statistical analysis showed significant differences in resonance frequency at implant insertion between groups 1 and 2 (P = 0.047) and between groups 1 and 3 (P = 0.002). When repeating the resonance frequency analyses at second stage surgery and at one-year follow-up, no significant differences were detected between any of the groups. It was shown that the stability of implants placed in softer bone seemed to "catch up" over time with more dense bone sites.

Topics: Aged; Bone Density; Dental Implantation, Endosseous; Dental Prosthesis, Implant-Supported; Female; Humans; Jaw, Edentulous; Male; Mandible; Middle Aged; Radiography; Statistics, Nonparametric; Torque