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Concept: Osseointegration

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As a result of major ablative surgery, head and neck oncology patients can be left with significant defects in the orofacial region. The resultant defect raises the need for advanced reconstruction techniques. The reconstruction in this region is aimed at restoring function and facial contour. The use of vascularised free flaps has revolutionised the reconstruction in the head and neck. Advances in reconstruction techniques have resulted in continuous improvement of oral rehabilitation. For example, endosteal implants are being used to restore the masticatory function by the way of prosthetic replacement of the dentition. Implant rehabilitation usually leads to improved facial appearance, function, restoration of speech and mastication. Suitable dental implant placement’s site requires satisfactory width, height and quality of bone. Reconstruction of hard tissue defects therefore will need to be tailored to meet the needs for implant placement.The aim of this feasibility study was to assess the compatibility of five standard commercially available dental implant systems (Biomet 3i, Nobel Biocare, Astra tech, Straumann and Ankylos) for placement into vascularised fibula graft during the reconstruction of oromandibular region.Radiographs (2D) of the lower extremities from 142 patients in the archives of the Department of Radiology in University College London Hospitals (UCLH) were analysed in this study. These radiographs were from 61 females and 81 males. Additionally, 60 unsexed dry fibular bones, 30 right sided, acquired from the collection of the Department of Anatomy, University College London (UCL) were also measured to account for the 3D factor.In the right fibula (dry bone), 90% of the samples measured had a width of 13.1 mm. While in the left fibula (dry bone), 90% of the samples measured had a width of 13.3 mm. Fibulas measured on radiographs had a width of 14.3 mm in 90% of the samples. The length ranges of the dental implants used in this study were: 7-13 mm (Biomet 3i), 10-13 mm (Nobel biocare), 8-13 mm (Astra Tech), 8-12 mm (Straumann ) and 8-11 mm (Ankylos).This study reached a conclusion that the width of fibula is sufficient for placement of most frequently used dental implants for oral rehabilitation after mandibular reconstructive procedures.

Concepts: Implants, Dental implant, Oral and maxillofacial surgery, Osseointegration, Free flap, Per-Ingvar Brånemark, Nobel Biocare, University College London

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The surface topography of implant fixture is an important factor affecting the osseointegration. We herein demonstrated the effects of surface microtopography of titanium disks on proliferation and differentiation of osteoblast-like cells isolated from rat calvariae. Titanium disks with machine surface (MS), rough surface (R1) and rough surface combined with small cavities (R2) were used in an in vitro culture system. Rough surfaces (R1 and R2 disks) induced stronger osteoblast proliferation and differentiation (BGP and sclerostin mRNA expressions and calcium content) than the smooth surface (MS disk). Furthermore, surface microtopography of R2 disk, which was rough with small cavities, more strongly induced cell proliferation and mineralized bone matrix production than R1 disk. Our results suggest that surface microtopography influences osteoblast proliferation and differentiation. R2 disk, which is rough with small cavities, may be used in implant fixtures to increase osseointegration.

Concepts: DNA, Bone, Cell nucleus, Gene expression, Dental implant, Surface, Osseointegration, Differential geometry

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AIM: The first aim of the present experiment was to compare bone healing at implants installed in recipient sites prepared with conventional drills or a piezoelectric device. The second aim was to compare implant osseointegration onto surfaces with and without dendrimers coatings. MATERIAL AND METHODS: Six Beagles dogs were used in this study. Five implants with two different surfaces, three with a ZirTi(®) surface (zirconia sand blasted, acid etched), and two with a ZirTi(®) -modified surface with dendrimers of phosphoserine and polylysine were installed in the right side of the mandible. In the most anterior region (P2, P3), two recipient sites were prepared with drills, and one implant ZirTi(®) surface and one coated with dendrimers implants were installed at random. In the posterior region (P4 and M1), three recipient sites were randomly prepared: two sites with a Piezosurgery(®) instrument and one site with drill and two ZirTi(®) surface and one coated with dendrimers implants installed. Three months after the surgery, the animals were sacrificed for histological analysis. RESULTS: No complications occurred during the healing period. Three implants were found not integrated and were excluded from analysis. However, n = 6 was obtained. The distance IS-B at the buccal aspect was 2.2 ± 0.8 and 1.8 ± 0.5 mm, while IS-C was 1.5 ± 0.9 and 1.4 ± 0.6 mm at the Piezosurgery(®) and drill groups, respectively. Similar values were obtained between the dendrimers-coated and ZirTi(®) surface implants. The BIC% values were higher at the drill (72%) compared to the Piezosurgery(®) (67%) sites. The BIC% were also found to be higher at the ZirTi(®) (74%) compared to the dendrimers-coated (65%) implants, the difference being statistically significant. CONCLUSION: This study has revealed that oral implants may osseointegrate equally well irrespective of whether their bed was prepared utilizing conventional drills with abundant cooling or Piezosurgery(®) . Moreover, the surface coating of implants with dendrimers phosphoserine and polylysine did not improve osseointegration.

Concepts: Implants, Coating, Dental implant, Osseointegration, Implant, Piezoelectricity, Coatings, Per-Ingvar Brånemark

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Background: To date, very few experimental studies have addressed the effect of bone drilling technique and sequence on dental implant osseointegration. In this study, we hypothesized that there would be no differences in osseointegration when reducing the number of drills for osteotomy compared to the conventional drilling protocols. Methods: Seventy-two implants (diameter 3.75 mm and diameter 4.2 mm, n=36 for each diameter) were bilaterally placed in the tibia of 18 beagles for 1, 3, and 5 weeks. Half of the implants of each diameter were placed using a simplified drilling procedure (pilot and final drill) and the other half were placed using a conventional drilling procedure (all drills in sequence). The retrieved samples were subjected to histologic/histomorphometric evaluation. Results: Histology showed that new bone formed around the implant and inflammation or bone resorption was not evident for both groups. Histomorphometrically, the simplified group presented significantly higher bone-to-implant contact and bone area fraction occupancy as compared to the conventional group after 1 week, however, no differences were detected at 3 and 5 weeks. Conclusion: It can be suggested that bone responses to the implant with the simplified protocol is comparable to the conventional protocol.

Concepts: Implants, Prosthetics, Drill, Dental implant, Titanium, Oral and maxillofacial surgery, Osseointegration, Per-Ingvar Brånemark

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BACKGROUND: New implant designs are continuously introduced to the market. It is important to evaluate and report on their clinical performance when used in everyday practice. PURPOSE: The aim of the present study was to evaluate the clinical performance of a novel hydrophilic dental implant for 1 year. MATERIALS AND METHODS: A total of 49 patients previously treated with 102 hydrophilic dental implants (Neoss Proactive, Neoss Ltd, Harrogate, UK) were retrospectively evaluated with regard to survival rate and marginal bone loss. Fifty-four implants were installed in maxillae and 48 in mandibles to replace single teeth (n = 21), to support partial bridges (n = 26), total maxillary bridges (n = 2), or mandibular overdentures (n = 2). The majority of patients (n = 37) had implants placed in healed sites without any adjunctive procedures. In 12 patients, implants were immediately placed in extraction sockets or in conjunction with maxillary sinus floor augmentation. All implant sites had been classified according to the Lekholm and Zarb index. Baseline and 1-year intraoral radiographs were used to calculate marginal bone levels and bone loss. Implant stability quotient (ISQ) measurements had been taken at placement and after 3 to 4 months of healing RESULTS: The implants became rapidly covered with blood at the first contact. One implant was lost, giving a cumulative survival rate (CSR) of 99.0% after 1 year. The marginal bone loss amounted to 0.7 ± 0.6 mm with 3.5% of the implants showing more than 2 mm of bone loss and no implant more than 3 mm bone loss after 1 year. The primary stability was found to be 72.7 ± 7.5 ISQ, which slightly increased to 73.6 ± 7.2 ISQ (NS) after 3 to 4 months of healing. The stability was significantly higher in the mandible than in the maxilla at placement and after healing. CONCLUSION: In this limited clinical study, the use of a novel hydrophilic dental implant results in favorable short-term outcomes.

Concepts: Mandible, Implants, Dental implant, Titanium, Dentistry, Osseointegration, Implant stability quotient, Maxilla

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This study applied femtosecond laser technology to zirconia dental implants (Bredent GmbH & Co.KG, Senden, Germany) to generate a surface texture of microgrooves over the entire intraosseous surface, analyzing its behavior in an in vivo model in comparison with titanium implants with sandblasted and acid-etched surfaces.

Concepts: Implants, Dental implant, Surface, Titanium, Osseointegration, Dog, Hound

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Alveolar distraction osteogenesis (ADO), a novel bone augmentation technique, is gaining acceptance in restoring the vertical bone discrepancy between the transplanted graft and the residual alveolar bone after mandibular reconstruction. This case series presents the outcomes of ADO in fibula-reconstructed mandibles rehabilitated with dental implants, with an emphasis on clinical indications, surgical protocol, clinical outcomes, histologic evidence, and complications.

Concepts: Implants, Dental implant, Dentistry, Oral and maxillofacial surgery, Osseointegration, CAD/CAM Dentistry

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The present study evaluated the effect of different drilling dimensions (undersized, regular, and oversized) in the insertion and removal torques of dental implants in a beagle dog model.

Concepts: Present, Time, Implants, Modern history, Implantation, Dental implant, Osseointegration

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Purpose: To present a new technique for sandwich osteoplasty in the posterior mandible and to evaluate its feasibility as part of dental implant treatment. Materials and Methods: A retrospective study of sandwich osteoplasty in the posterior mandible was conducted. No osteosynthetic material was used to stabilize the osteotomy. Fixation was achieved with the interposition of two bone blocks harvested from the retromolar region. Results: Eighteen patients with 26 sites of severe atrophy of the posterior mandible were treated. After a healing period of 4 months, 53 dental implants were inserted into the augmented region. The implants were loaded with single crowns or fixed dental prostheses 3 months after placement. The mean vertical bone gain after 4 months of healing was 4.2 mm (standard deviation 1.4 mm). The average bone loss between augmentation and implantation was 2.3 mm (35.4%). All implants osseointegrated and showed no clinical signs of peri-implantitis. In three subjects, the elevated bony segment perforated the lingual mucosa near the adjacent teeth after excessive elevation (> 6 mm) but healed without any sequelae. Conclusion: An alternative method for vertical alveolar ridge augmentation of the posterior mandible is presented. No osteosynthetic material is required for fixation, and related complications can be avoided. Further prospective clinical studies are required to demonstrate the feasibility of this technique versus the conventional sandwich osteoplasty.

Concepts: Implants, Prosthetics, Arithmetic mean, Standard deviation, Dental implant, Dentistry, Oral and maxillofacial surgery, Osseointegration

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Abstract Purpose: to evaluate the action of recombinant human growth hormone (rhGH) on osseointegration of titanium implants in rabbits. Materials and Methods: fourteen adult new Zealand rabbits, with age of 30 weeks, were used in the study, randomly divided into 2 groups. In each animal, two (2.2mm x 6mm) pure titanium implants were placed in the left tibia. In one group (test group), 1UI (0.3mg) of rhGH as a lyophilized powder was applied to each osteotomy site prior to implant placement. Only titanium implants were placed in osteotomy sites of the other group (control). Animals were sacrificed at 14 and 42 days after surgery and samples were then prepared for histological analysis and biomechanical test. Results: biomechanical test showed tensile pull-out stress values of 33.88 N/cm2 for controls and 59.26 N/cm2 for the rhGH group at 14 days and 25.99 N/cm2 and 29.69 N/cm2 for control and test group respectively at 42 days. Scanning electron microscope (SEM) analysis showed a more uniform and abundant bone tissue in contact to the implants in the test group at 14 days, and no differences between groups in 42 days. Furthermore, histological analysis also showed accelerated bone repair in 14 days and a more advanced stage of bone remodeling for the rhGh-treated group when compared to controls after 42 days of repair. Conclusions: such results show that the topical use of rhGH induce new bone formation in the early stages of bone repair and hence accelerates osseointegration of titanium dental implants.

Concepts: Bone, Skeletal system, Growth hormone, Scanning electron microscope, Dental implant, Titanium, Oral and maxillofacial surgery, Osseointegration