Soft tissue attachment on sol-gel-treated titanium implants in vivo.

This study was designed to examine the attachment and reactions of soft tissues to sol-gel-derived TiO2 coatings. In the first experiment, TiO2 coated and uncoated titanium cylinders were placed subcutaneously into the backs of rats for 3, 11 and 90 days. Tissue response and implant surfaces were characterized with routine light microscopy and scanning electron microscopic (SEM) analysis. In the second experiment, TiO2-coated and uncoated discs were implanted subcutaneously into the backs of rats for 14 and 21 days. The discs were pulled out from the implantation sites with a mechanical testing device using a constant speed of 5 mm/min. Rupture force was registered, after which the discs were assigned for SEM and transmission electron microscopic (TEM) analysis. All the coated implants showed immediate contact with the surrounding soft tissues without a clear connective tissue capsule. Significantly better soft tissue response was measured for all the coated compared to the uncoated cylinders (p<0.01). Higher rupture forces were measured for all coated discs, although the differences were not statistically significant. An immediate and tight connection between connective tissue fibroblasts and coatings was noticed in TEM analysis. Our study indicates that TiO2 coatings improve soft tissue attachment on a titanium surface.

Comparison between sol-gel-derived anatase- and rutile-structured TiO2 coatings in soft-tissue environment.

The bioactivity of the surface reactive TiO(2) coatings for medical implants can be locally modified by CO(2) laser processing to match with the properties of surrounding tissues. The TiO(2) coatings heat-treated at 500 degrees C exhibit in vitro bioactivity. With further CO(2) laser treatment they exhibit enhanced in vitro bioactivity. The aim of this in vivo study was to compare the performance of heat-treated anatase-structured TiO(2) coatings with preheat-treated and CO(2) laser-treated rutile-structured coatings in terms of their ability to attach soft connective tissues. The coatings were characterized with TF-XRD and AFM. TiO(2)-coated discs were implanted in rats. The samples were analyzed with routine histology, SEM-EDS, and TEM. In both groups, already at 3 days, soft connective tissues were in immediate contact with the surface. No thick crystalline CaP layer was detected by SEM-EDS, but a thin amorphous CaP layer was detected by XPS. No gap between the cell membrane and the coating could be observed in TEM pictures. No differences were observed between the anatase- and rutile-structured coatings in terms of tissue responses. Further studies are needed to verify if the tissues are adherent to the surface of the implant.

Frontal bone defect repair with experimental glass-fiber-reinforced composite with bioactive glass granule coating.

OBJECTIVE: The aim of this preliminary study was to test the bioactive glass-coated fiber-reinforced composite (FRC) as a reconstruction material in the treatment of experimental defects in the frontal bone of rabbits. METHODS: FRC made of E-glass fiber and BisGMA-PMMA resin matrix system was used in the study. Pieces of nonpolymerized FRC were coated with particulate bioactive glass granules S53P4 (BAG), and then the FRC was polymerized and post-cured by heat in air to reduce the quantity of residual monomers, and to sterilize the material for the animal study. Two round defects (5 mm in diameter) were drilled in the upper bony walls of 12 NZW rabbits' frontal sinuses, and rectangular FRC plates were applied over the defects. In the control group, no FRC plates were used. The bone defect healing process was evaluated on histological sections at 3, 6, and 8 weeks, postoperatively. SEM-EDX analysis was used to determine reactive layers of bioactive glass granules. RESULTS: The healing progressed from the fibroconnective tissue phase at 3 weeks to lamellar bone formation at 6 and 8 weeks. The difference in new bone formation between the implantation groups and control groups was not statistically significant, although in some animals the effect of the implant on bone healing was clearly positive. A moderate foreign body reaction was seen on the implant surface where BAG granules did not uniformly cover the implant's polymer matrix. CONCLUSIONS: This study suggests that the tested FRC implant with bioactive glass coating provides an alternative for bone defect reconstruction. However, more research on this composite material and its biocompatibility is needed.

Implants coated with bioactive glass by CO2-laser, an in vivo study.

Due to ageing of the population, the number of revision operations is expected to increase. Thus good fixation of medical implants is crucial for successful treatment. In our previous studies, a method to coat titanium implants with bioactive glass (BAG) via CO2 laser treatment was introduced. It allows to localise the application of a bioactive coating, without heat treatment of the whole implant. In the present study, cylindrical titanium implants were used (BAG-coated, control group: NaOH-treated and grit-blasted Ti). Three implants were placed in each femoral epicondyle of six rabbits. After eight weeks the animals were sacrificed. Half of the implants were subjected to a torsional loading test. In the control groups, the failure occurred at the bone-implant interface, in the BAG group the failure occurred mainly in the reacted glass. The implants coated with BAG were integrated into host bone without a connective tissue capsule and were surrounded by significantly more bone than the control implants. The findings indicate clearly that the use of CO2 laser radiation to create BAG coatings did not inhibit the bioactive properties of the glass in terms of osteoconduction.

In vitro Ca-P precipitation on biodegradable thermoplastic composite of poly(epsilon-caprolactone-co-DL-lactide) and bioactive glass (S53P4).

Bioactive properties of composites containing poly(epsilon-caprolactone-co-DL-lactide) with molar ratio 96/4 and bioactive glass (BAG), S53P4, were tested in vitro. The glass content in the tested materials was 40, 60 or 70 wt%, and two granule size ranges (<45 and 90-315 microm) were used. The composites were analysed for their apatite-forming ability. This was determined as a function of time by the dissolution pattern of Si and Ca ions and structural changes on the specimen surfaces. Composite specimens were immersed in simulated body fluid at 37 degrees C for up to 6 months. The changes in Si and Ca concentrations of the immersion medium were determined with UV-Vis and atomic absorption spectrophotometry. The calcium phosphate precipitation and apatite formation were evaluated by scanning electron microscopy (SEM) and infra-red spectroscopy (IR) using the attenuated total reflectance (ATR) system. The SEM and SEM-EDX analysis of the depositions formed on the composite surfaces was in line with the changes in ion concentrations. The clearest results with IR were seen in the material containing 60 wt% small glass particles. The results indicate that composites containing over 40 wt% BAG granules are bioactive, and that a higher BAG surface area/volume ratio favors the apatite formation in vitro.

Anterior Z250 resin composite restorations: one-year evaluation of clinical performance.

The purpose of this practice-based study was to compare the clinical performance of a new universal composite resin material (Z250) used for Class III and V cavities in anterior teeth. Restorative materials (Z250 and Z100; 3 M ESPE) placed by six operators were used for a total of 150 restorations during the 6-month enrollment period. After 1 year, 141 restorations (76 Z250 and 66 Z100) were available and evaluated for overall quality, color match, marginal adaptation, surface appearance and the presence of secondary caries, using modified USPHS criteria. The overall quality was excellent for both materials and no significant changes were noted during the follow-up. None of the scores between the two materials were statistically significant. Major changes were seen in color match and surface appearance. At baseline, the color match of 71% of Z250 and 62% of Z100 was rated as Alfa, after 1 year the figures were 60 and 65%. Regarding surface appearance, 97% of the Z250 were rated Alfa at baseline, whereas at 1 year the figure was 76%. For Z100, the scores were 94 and 79%, respectively. After 1 year, the clinical performance of Z250 restorative composite resin was clinically acceptable and similar to that of Z100.

New drugs, new techniques, new indications in pediatric regional anesthesia.

The use of regional anesthesia in children represents one of the most effective methods for perioperative analgesia and postoperative pain control. Things have been dramatically changed in the last two decades due to the appearance of new safer drugs and new tools; moreover new techniques were introduced showing their efficacy. In this paper we briefly describe the efficacy of new local anesthetics and adjuvants; we review the use of continuous peripheral blocks and other not very diffused techniques of regional anesthesia.

Spinal anesthesia in children: pro.

Spinal anaesthesia, first introduced in children at beginning of 20th century, offers adequate intraoperative anaesthetic conditions (analgesia and muscle relaxation). The technique is easy to perform even if lumbar puncture is more difficult when the children is smaller. It has not been observed haemodynamic modifications especially in patients under 5 year of age; duration of spinal anaesthesia is shorter if compared to adults and post dural puncture headache (PDPH) after spinal anaesthesia is as common in children as it is in adults, but was usually mild and very short lasting. PDPH has not been correlated with the type of spinal needle used. Hyperbaric solution of local anaesthetics like bupivacaine and tetracaine are preferable. The only adjuvant used for spinal anesthesia in children is morphine, which should be administered only in patients admitted to high dependency unit in the postoperative period. Spinal anaesthesia is indicated mainly in sub umbilical surgical procedures lasting no more than 90 minutes and particularly in the surgical treatment of former premature infants who present an higher risk with regional anaesthesia.