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Biomedical subjects

David A Puleo

Publications and source records attributed to David A Puleo.

5 recordsLinked to original sources
PubMed2006

Implant surfaces.

Available in many shapes, sizes, and lengths, dental implants are also crafted from different materials with different surface proper-ties. Among the most desired characteristics of an implant are those that ensure that the tissue-implant interface will be established quickly and then will be firmly maintained. Because many variables affect oral implants, it is sometimes difficult to reliably predict the likelihood of an implant's success. It is especially difficult to assess whether the various modifications in the latest implants deliver improved performance. This article focuses primarily on important surface characteristics and their potential effects on the performance of dental implants.

Biocompatible Materials↗
PubMed2005

Bioactive glass three decades on.

Bioglasses were first introduced in the early 1970s and since have found wide use in dentistry. The original 45S5 bioglass, as described by Hench, is a silica-based melt-derived glass characterized by a Si02 content of less than 60%, a high Na2O and CaO content, and a high CaO:P2O5 ratio. Bioactivity has been defined as the ability of an implant to form a bond with living tissue. These glasses exhibit bone bonding, a phenomenon also observed with other bioactive ceramics. This process is a result of the surface reactive silica, calcium, and phosphate groups that are characteristic of these materials. Silica is believed to play a critical role in bioactivity. Bioactive glass is a very biocompatible material. There is a good deal of experimental data supporting its use in a variety of clinical applications, including ridge preservation, sinus augmentation, and the repair of periodontal bone defects. There are limitations inherent in the bioglass products that are currently available. They are granular in nature and cannot be depended upon to serve reliably as space-making devices. Although they are quite biocompatible and exhibit bone bonding, bioglasses are not osteoinductive and are not capable of forming bone in ectopic sites (although they can be used to deliver osteopromotive growth factors). The range of applications for these products could be extended if the material could be made in various space-making forms. Incorporation or coating with osteogenic agents such as growth factors might be worthwhile. The full potential of bioactive glasses has yet to be fully realized.

Animals↗
PubMed2005

Calcium sulfate: a review.

Calcium sulfate has a long history of use in medicine and dentistry. It exists in two forms (alpha and beta), which differ greatly in physical properties. It has been used in bone regeneration as a graft material and graft binder/extender and as a barrier in guided tissue regeneration. It is an unusually biocompatible material and is completely resorbed following implantation. It does not evoke a significant host response and creates a calcium-rich milieu in the area of implantation. These calcium ions may provide some stimulation to osteoblasts, which may account for some of the positive results reported with the material. Calcium sulfate can be used as a delivery vehicle for growth factors and antibiotics, although this application has not been thoroughly exploited in the clinical setting. It has been shown that tissue will often migrate over calcium sulfate if primary closure cannot be obtained, which provides further evidence of its biocompatibility. The raw material from which calcium sulfate is made is relatively inexpensive and abundant. Despite these advantages, calcium sulfate has never attracted the same degree of research interest as have other biomaterials. Recently, however, it has enjoyed a resurgence of sorts in the areas of periodontology, sinus augmentation, and orthopedic surgery. Future research must be directed toward improving handling characteristics and strength, while preserving the biocompatibility of the material.

Animals↗
PubMed2002

A study of the antiresorptive activity of salmon calcitonin microspheres using cultured osteoclastic cells.

The purpose of this study was to evaluate salmon calcitonin (sCT) microspheres in vitro for their antiresorptive activity using cultured osteoclastic cells. The antiresorptive activity of sCT-loaded microspheres, prepared from a low molecular weight hydrophilic poly (lactide-co-glycolide) polymer (PLGA), was studied using bone marrow culture cells harvested from juvenile rats and cultured on slices of devitalized bone for up to 4 weeks. The resorptive activity of osteoclastic cells was quantified in terms of number and type of resorption pits and total area of resorption. Microspheres containing 5.1% sCT released 70% peptide in 2 weeks and 88% in 4 weeks. All sCT treatments inhibited total resorptive activity. A dose-dependent decrease in resorption was observed with sCT microspheres at 2 weeks. The high dose (10 mg of microspheres) produced a 99.5% decrease in resorption at 3 weeks, while the low dose (1 mg) produced an 80% reduction. Exposure of cultures to soluble sCT and sCT-loaded microspheres caused a decrease in the number of large pits, which were the predominant type formed in control cultures. Thus, this system could serve as an in vitro method to evaluate the antiresorptive effect of PLGA-sCT microspheres.

Animals↗