Five-Year Prospective Study of Immediate/Early Loading of Fixed Prostheses in Completely Edentulous Jaws with a Bone Quality-Based Implant System

Background : The concept of immediate loading of root-form implants for fixed restorations has received increasing interest over the last 5 years. Several authors have commented on parameters that may influence results, including implant number, implant length, bone density, and patient habits. The trigger for bone remodeling around an implant may occur from the surgical trauma of insertion or the mechanical environment of strain at the interface. In the classic two-stage approach, these were divided episodes, separated by 3 to 6 months. Immediate loading compresses this time frame; the two driving mechanisms for bone repair occur concurrently. A scientific approach to the interface development is to match the bone healing response of trauma (woven bone of repair) to the response of mechanical load (reactive woven bone), so the sum of these two entities does not result in fibrous tissue formation and clinical mobility of the implant. Purpose : It is the purpose of this article to review the scientific rationale of these statements and coordinate them to bone physiology and bone biomechanics. Materials and Methods : Findings from previous reports in the literature were reviewed and summarized to form the basis of a prospective study using a bone quality-based implant system (Biohorizons, Maestro Dental Implants, Birmingham, AL, USA). A transitional prosthesis was delivered either on the day of surgery or within 2 weeks for 30 patients and 31 arches. A total of 244 implants were used to support these restorations, for an average of 7.8 implants per prosthesis. After 4 to 7 months, the final restorations were fabricated. One year after the final restoration was loaded, the implant survival was 100%; the 31 restorations also had a survival of 100% over this time frame. This report presents these implants and restorations over a 1- to 5-year period, with an average follow-up period of 2.6 years. Results : The bone loss from implant insertion to final prosthesis delivery averaged 0.7 mm. The first-year bone loss after final prosthesis delivery averaged 0.07 mm. A slight increase in bone height was observed after the first year, but generally no increase was observed over the remaining evaluation period. Conclusions : In the current report, no implant failure occurred, and crestal bone loss values were similar to or less than values reported with the conditional two-stage approach. This may be related to the number and position of implants, implant design, and/or the surface condition of the implant loading.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73973/1/j.1708-8208.2003.tb00178.x.pd

The symmetric 3D organization of connective tissue around implant abutment: a key-issue to prevent bone resorption

Symmetric and well-organized connective tissues around the longitudinal implant axis were hypothesized to decrease early bone resorption by reducing inflammatory cell infiltration. Previous studies that referred to the connective tissue around implant and abutments were based on two-dimensional investigations; however, only advanced three-dimensional characterizations could evidence the organization of connective tissue microarchitecture in the attempt of finding new strategies to reduce inflammatory cell infiltration. We retrieved three implants with a cone morse implant–abutment connection from patients; they were investigated by high-resolution X-ray phase-contrast microtomography, cross-linking the obtained information with histologic results. We observed transverse and longitudinal orientated collagen bundles intertwining with each other. In the longitudinal planes, it was observed that the closer the fiber bundles were to the implant, the more symmetric and regular their course was. The transverse bundles of collagen fibers were observed as semicircular, intersecting in the lamina propria of the mucosa and ending in the oral epithelium. No collagen fibers were found radial to the implant surface. This intertwining three-dimensional pattern seems to favor the stabilization of the soft tissues around the implants, preventing inflammatory cell apical migration and, consequently, preventing bone resorption and implant failure. This fact, according to the authors’ best knowledge, has never been reported in the literature and might be due to the physical forces acting on fibroblasts and on the collagen produced by the fibroblasts themselves, in areas close to the implant and to the symmetric geometry of the implant itself

Peri-implant tissue and radiographic bone levels in the immediately restored single-tooth implant: A retrospective analysis

Background: The purpose of this study was to compare and evaluate bone and soft tissue levels in immediately restored single implants positioned in the esthetic anterior region. Methods: Forty-five patients requiring single-implant crowns in the anterior region received 52 implants, which were restored immediately. Periapical radiographs and digital images of 368 interproximal sites were taken during regular follow-ups from 24 to 72 months after surgery. The interproximal papilla was assessed and compared to the distances between the bone crest and the contact point between the natural teeth and the restoration crown. Results: Bone loss in the bone peak was statistically significantly greater in the postextraction sockets compared to the healed sites. No significant correlation was found between bone loss and papilla presence. The interproximal papilla showed average growth and decreased, in percentage terms, when the distance between the bone crest and the contact point between the tooth and the restoration crown was >7 mm. Conclusions: In the interproximal area between the implant and the natural tooth, the papilla does not seem to be affected by the peri-implant bone loss. The contact point between the natural tooth and the restoration crown should be ≤7 mm from the bone peak. Immediate restoration did not seem to cause a greater average amount of bone loss compared to that reported previously for one- and two-stage surgical procedures after the first year of function

A Narrative Review of the Histological and Histomorphometrical Evaluation of the Peri-Implant Bone in Loaded and Unloaded Dental Implants. A 30-Year Experience (1988–2018)

Background: The aim of the present review was to assess the histological and histomorphometrical data from the paper published by our Laboratory on peri-implant bone in dental implants in different loading conditions. Methods: The papers published in different implant loading conditions, in dental implants retrieved from humans, and in the Hard Tissues Research Center of the University of Chieti-Pescara, Italy, were screened on MEDLINE/PubMed, Embase, Scopus, and other electronic databases until 31 December 2018. Only articles that reported the histological and histomorphometrical values of the Bone-Implant Contact (BIC) were selected. Results: The system selection provided a total of 155 papers. The manuscripts included for the narrative review were 57. These papers provided histological and histomorphometrical data. Conclusions: The bone remodeling around dental implants was found to be a dynamic process; loading changed the microstructure of the peri-implant bone; and implants were found to provide a successful function, over several decades, with different range of degrees of BIC in vivo (varying from a little more than 30% to a little more than 90%). Loaded implants presented a 10%–12% higher BIC values when compared to submerged, unloaded implants, and rougher surfaces had, on average, about a 10% higher BIC than machined surfaces

Outcome analysis of immediately placed, immediately restored implants in the esthetic area: The clinical relevance of different interimplant distances

Background: The purpose of this study was to compare and evaluate bone and soft tissue levels between immediately placed, immediately restored implants positioned in the esthetic anterior region with different interimplant distances (IID). Methods: Forty-nine patients requiring multiple implant restorations in the anterior regions received 152 implants, which were restored immediately. Periapical radiographs and digital images of 99 interimplant sites were taken at the regular follow-up examinations at 0, 6, 12, and 24 months after surgery. They were digitally recorded and analyzed. The presence of the interproximal papilla was assessed and compared to the distances between the bone crest and the contact point between the natural teeth and the restoration crowns. Results: Implants with an IID <2 mm seemed to lose less bone laterally. When the IID was <2 mm, vertical crestal bone loss was significantly greater than in the group with IID >4 mm. The percentage of the interproximal papilla presence decreased when the distance between the bone crest and the contact point between the two restoration crowns was >6 mm and when two implants were placed at a distance >= 4 mm. Conclusions: To guarantee a better esthetic result in immediately placed, immediately restored implants, the contact point between the two prosthetic crowns should be placed at 3 to 4 mm, and never >6 mm, from the bone peak. Two adjacent implants should be placed at a distance >2 and <4 mm

Bone regeneration with phycogene hydroxyapatite. a pilot histological and histomorphometrical study in rabbit tibia defects

Bone regeneration with phycogene hydroxyapatite. a pilot histological and histomorphometrical study in rabbit tibia defect

RETENTION STRENGTH OF CONICAL WELDING CAPS FOR FIXED IMPLANT-SUPPORTED PROSTHESES.

PURPOSE: This study evaluated the retention strength of welding caps for Ankylos standard abutments using a pull-out test. MATERIALS AND METHODS: Each sample consisted of an implant abutment and its welding cap. The tests were performed with a Zwick Roell testing machine with a 1-kN load cell. RESULTS: The retention strength of the welding caps increased with higher abutment diameters and higher head heights and was comparable or superior to the values reported in the literature for the temporary cements used in implant dentistry. CONCLUSION: Welding caps provide a reliable connection between an abutment and a fixed prosthesis without the use of cemen