1,720,984 research outputs found
Prevention of muscle and nerve damage after a prolonged ischemia/reperfusion syndrome: An experimental animal model
No full textAn experimental, rat model, of limb replantation was developed to evaluate and compare the efficacy of SOD and mPEG-SOD (native and modified with polyethylene glycole superoxide dismutase) or PAcM-SOD (polyacriloilmorpholine superoxide dismutase) in preventing ischemia- reperfusion damage. In particular, the current research focused on the technical procedure employed for the study of the newly activated motor end-plates after ischemia/reperfusion injury. The experiment was carried out on CO Wistar rats, randomly divided into four groups, submitted to 4 hours and 30 minutes of ischemia of the left hindlimb, followed by reperfusion. Results showed a better limb survival in the mPEG-SOD group (87%) in comparison to other three groups (p<0.05)
INFLUENCE OF IMPLANT-ABUTMENT INTERFACE DESIGN ON BONE AND SOFT TISSUE LEVELS AROUND IMMEDIATELY PLACED AND RESTORED SINGLE-TOOTH IMPLANTS: A RANDOMIZED CONTROLLED CLINICAL TRIAL.
No full textPURPOSE: The purpose of the present study was to compare the clinical and radiographic outcomes of single implants immediately placed and restored with two different implant-abutment connections.
MATERIALS AND METHODS: Forty subjects requiring single maxillary premolar replacement were consecutively included in this study and prospectively followed for 12 months. One implant was placed at the time of tooth extraction and immediately restored in each patient. Subjects were randomly selected to receive either prosthetic abutments with a Morse taper connection and a platform switch (test group) or conventional abutments with an internal connection and a matching diameter (control group). A provisional screw-retained crown was positioned and adjusted for nonfunctional loading within 24 hours. Four months later, the definitive crowns were delivered. Periodontal parameters and clinical and radiographic measurements of soft and hard tissue levels were recorded at the moment of prosthesis placement and at 4 and 12 months afterward. Means of the two groups were compared using paired and independent-sample t tests (P = .05).
RESULTS: Of the 40 patients recruited, 38 (24 women and 14 men) completed the study. No implants were lost in the control group, whereas one implant failed in the test group. At the 12-month examination, no statistically significant differences were seen between the two groups for periodontal parameters, marginal soft tissue level change, or papilla height (P > .05), but greater marginal bone loss was observed at the control sites (0.51 ± 0.24 mm) compared to the test sites (0.2 ± 0.17 mm) (P = .0004).
CONCLUSION: Although the control group demonstrated a slight increase in marginal bone loss compared to the test group, the peri-implant soft tissues were very stable with both types of implant-abutment connection after 12 months of loading
PRELIMINARY 2-YEAR REPORT ON TREATMENT OUTCOMES FOR 6-MM-LONG IMPLANTS IN POSTERIOR ATROPHIC MANDIBLES.
No full textPurpose: The aim of this study was to prospectively evaluate clinical and radiographic outcomes of ultrashort implants (4-mm diameter, 6-mm length) supporting fixed partial dentures in severely atrophic posterior mandibles. Materials and Methods: Twenty-five patients with posterior edentulous mandibular spans and 7- to 8-mm residual bone heights above the mandibular canal were enrolled. In total, 61 submerged implants were placed and loaded 5 to 6 months later. Patients were followed for 2 years after prosthesis connection with clinical, radiographic, and resonance frequency analysis (RFA) examinations. Results: Two implants failed in one patient before loading; all other implants showed favorable clinical and radiographic findings throughout the observation period (2-year survival and success rate: 96.8%). Postoperative pain and swelling were negligible. Mean changes in marginal bone levels were stable (0.40 ± 0.23, 0.51 ± 0.38, and 0.60 ± 0.13 mm after 6 months and 1 and 2 years, respectively) and were unaffected by measured crown-to-implant ratios (range: 1.31 to 3.12). Mean RFA values increased significantly from implant placement (67.35 ± 6.67) to 2 years (72.91 ± 5.07, P < .0001). Prosthetic complications included two prosthesis decementations, three ceramic veneer chippings, and one prosthesis screw loosening. Conclusion: Within the limitations of the short follow-up period, the use of 6-mm-long implants was a predictable treatment method for patients with atrophic posterior mandibles and increased crown-to-implant ratios
Immediate Fixed Implant Rehabilitation of the Atrophic Edentulous Maxilla after Bilateral Sinus Floor Augmentation: A 12-Month Pilot Study
No full textPURPOSES:
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.
MATERIALS AND METHODS:
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.
RESULTS:
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).
CONCLUSIONS:
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
Maxillary sinus augmentation: Histologic and histomorphometric analysis
No full textPURPOSE:
Implant placement in the posterior maxilla may often be contraindicated because of insufficient bone volume and the presence of the maxillary sinus. In these situations, sinus floor lifting and grafting frequently have been proposed as the best treatment. The aim of this study was to compare histologically the use of 100% autogenous bone versus a combination of autogenous bone and corticocancellous pig bone for maxillary sinus augmentation.
MATERIALS AND METHODS:
Eighteen patients requiring bilateral maxillary sinus augmentation were selected for this study. Bone for grafting was harvested from the iliac crest. Each patient received 100% autogenous bone in 1 randomly selected sinus (control side) and a 1:1 mixture of autogenous bone and corticocancellous pig bone particles in the contralateral sinus (test side). Five months after the augmentation procedure, bone biopsy specimens were taken at the time of implant placement.
RESULTS:
No complications were observed during the surgical procedures; all patients healed uneventfully. No signs or symptoms of maxillary sinus disease were observed during the 5 months after surgery. No significant differences in bone percentages were observed in the bone biopsies from test and control sides.
DISCUSSION AND CONCLUSION:
It could be concluded from this study that corticocancellous pig bone particles can be successfully used in a 1:1 mixture with autogenous bone from the iliac crest for maxillary sinus augmentation in cases of severely atrophic maxilla
In vitro behaviour of osteoblasts cultured on orthopaedic biomaterials with different surface roughness, relative to uncoated and fluorohydroxyapatite-coated, the in vivo osteointegration rate
No full textComparison of calcitonin, alendronate and fluorophosphate effects on ovariectomized rat bone
No full textMedical grade calcium sulfate hemihydrate in healing of human extraction sockets: Clinical and histological observations at 3 months
Full text linkEpithelial apical migration on the surfaces of oral implants immediately placed after tooth extraction. A study in a mini-pig model.
No full textHISTOLOGIC AND HISTOMORPHOMETRIC EVALUATION OF ALVEOLAR RIDGE AUGMENTATION USING BONE GRAFTS AND TITANIUM MICROMESH IN HUMANS
No full textBackground: Recently, the use of titanium micromesh for alveolar bone augmentation has drawn interest; however, only limited histologic data are available on the quality of the bone regenerated. Therefore, this study compared the use of 100% intraoral autogenous bone to a combination of intraoral autogenous bone (70%) and bovine porous bone mineral (BPBM) (30%) for alveolar ridge augmentation with titanium micromesh histologically and histomorphometrically. Methods: Twelve partially edentulous patients required alveolar bone augmentation before implant insertion because of ridge resorption. The defect sites, six in the maxilla and six in the mandible, were reconstructed with particulate autologous bone (control group, N = 6) or a mixture of autologous bone and BPBM (test group, N = 6) in combination with titanium micromesh. Core biopsies were taken from the defect sites 8 to 9 months after grafting at the time of implant insertion. Results: Newly formed compact bone with a well-organized lamellar pattern was identified in all specimens. In the samples taken from the test group, the BPBM particles were surrounded completely by newly formed bone with no signs of resorption. The mean total bone volume was 62.38% +/- 13.02% in the control group and 52.88% +/- 11.47% in the test group. The soft tissue volume was 37.61% +/- 13.02% and 29.96% +/- 12.58%, respectively, and the residual BPBM volume was 17.15% +/- 2.72% in the test group. No statistical difference was observed in the histologic parameters evaluated, irrespective of graft type and site (P >0.05). Conclusion: Within the limits of this study, BPBM (30%) in combination with autogenous bone (70%) did not yield a lower percentage of new bone formed compared to autogenous bone alone in ridge augmentation with titanium micromesh
- …
