Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CEMENTATION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,711 records · Page 95Linked to original sources
PubMed1997

[Resorbable bone cements].

Bone cements are used to treat compression fractures, fill bone defects and improve implant fixation in osteoporotic patients through reinforcement of weak bone. When the fracture repair is complete the bone cement ideally should degrade. In general, calcium-phosphate bone cements are biodegradable and can fulfill this temporary function. Several research groups have developed calcium-phosphate bone cements in the last years which have a chemical structure similar to that of the apatite of bone. However the conditions for processing the cement intraoperatively, as well as the mechanical properties and degradation characteristic of the various products show great variations. Clinical long-term studies have not yet been reported so far. Whether these new types of bone cements fulfill all the requirements for clinical application is still not certain and remains to be determined in future studies.

Absorption↗
PubMed2001

Parathyroid hormone (1-34) increases attachment of PMMA cement to bone.

The attachment of an implant material to bone is related to the surface of the implanted material and the ability of the bone to form around the implant. Intermittent parathyroid (PTH) administration increases bone formation by stimulating osteoblastic activity. Little is known about the effect of PTH administration on orthopedic implant incorporation. The present study determined how PTH (1-34) administration influenced bone bonding, i.e., the bone-cement interfacial tensile strength, of vacuum-mixed polymethylmethacrylate (PMMA) bone cement (surface roughness; Ra, 4.8 microm). Bone bonding was evaluated by a detachment test. We used unloaded cement surfaces, which could be detached from the bone. Titanium plates were developed such that a cement fill was contained within a plate that was contained within a titanium holder. Thus, a flat cement surface came into contact with traumatized bone only, and the rest of the plate had no contact with tissue. After implantation of the plate in the left tibia, 20 adult male rats were injected daily with human PTH (1-34) at 60 microg/kg per injection (n = 10) or vehicle (n = 10); the animals were killed after 4 weeks. The plates were detached from the bone by a perpendicular force. PTH treatment increased the median pull-away strength (0.21 MPa), compared with that in the vehicle-treated rats, (0.04 MPa) (P = 0.02). The results suggest that PTH treatment may have the potential to enhance the incorporation of cemented orthopedic implants.

Animals↗
PubMed2003

Biomechanical evaluation of kyphoplasty and vertebroplasty with calcium phosphate cement in a simulated osteoporotic compression fracture.

Kyphoplasty and vertebroplasty with polymethylmethacrylate (PMMA) have been used for the treatment of osteoporotic vertebral compression fractures. We performed kyphoplasty and vertebroplasty with alpha-tricalcium phosphate cement (CPC) and PMMA to compare the biomechanical properties. Thirty osteoporotic vertebrae were harvested from nine embalmed cadavers. We randomized the vertebrae into four treatment groups: (1) kyphoplasty with CPC; (2) kyphoplasty with PMMA; (3) vertebroplasty with CPC; and (4) vertebroplasty with PMMA. Prior to injecting the cement, all vertebrae were compressed to determine their initial strength and stiffness. They were then recompressed to determine their augmented strength and stiffness. Although the augmented strength was greater than the initial strength in all groups, there was no significant difference between the two bone cements for either kyphoplasty or vertebroplasty. The augmented stiffness was significantly less than the initial stiffness in the kyphoplasty groups, but the difference between the two cements did not reach significance. In the vertebroplasty groups, the augmented stiffness was not significantly different from the initial stiffness. There was no significant difference between the two bone cements for either procedure when cement volume and restoration of anterior height were assessed. We concluded that kyphoplasty and vertebroplasty with CPC were viable treatment alternatives to PMMA for osteoporotic vertebral compression fractures.

Aged↗
PubMed2005

Evaluation of chitosan/beta-tricalcium phosphate microspheres as a constituent to PMMA cement.

Two methods, a traditional emulsion technique and a high voltage electrostatically modified encapsulation system, were used to fabricate degradable chitosan/beta -tricalcium phosphate (beta-TCP) microspheres. The two distinct kinds of microspheres both exhibited good sphericity and the beta-TCP was trapped well inside the chitosan gel. The microspheres prepared by high voltage electrostatic system exhibited a rougher outer surface and narrower size distribution. These microspheres were then used as an added constituent to commercially available PMMA bone cement. Four modified cement composites that were prepared with different composition ratios of the two kinds of chitosan/beta-TCP microspheres that were made from emulsion technique (C1P1 and C2P1) and from a process by a high voltage electrostatic system (EC1P1 and EC2P1) were compared with the PMMA cement (Pure P). The characteristics of these materials indicate that with the addition of chitosan/beta-TCP microspheres as a constituent into the PMMA cement significantly decreases the curing peak temperature. Furthermore, the setting time increases from 3.5 min to 9 min, as compared to the PMMA cement. These changes could be beneficial for the handling of the bone cement paste and causing less damage to the surrounding tissues. Understandably, the presence of chitosan/beta-TCP microspheres in the prepared composites reduced the ultimate compressive strength and bending strength. From the degradation test and SEM observations, the modified chitosan/beta -TCP/PMMA composites could be degraded gradually and create rougher surfaces that would be beneficial to cell adherence and growth.

Biocompatible Materials↗
PubMed2007

Shear bond strengths of glass-ionomer cements to sound and to prepared carious dentine.

The aim of this study was determine whether bonding of glass-ionomer cements to non-carious dentine differed from that to carious dentine. Five commercial cements were used, namely Fuji IX GP, Fuji IX capsulated, Fuji IX Fast capsulated (all GC, Japan), Ketac-Molar and Ketac-Molar Aplicap (both 3M-ESPE, Germany). Following conditioning of the substrate with 10% poly (acrylic acid) for 10 s, sets of 10 samples of the cements were bonded to prepared teeth that had been removed for orthodontic reasons. The teeth used had either sound dentine or sclerotic dentine. Shear bond strengths were determined following 24 h storage. For the auto-mixed cements, shear bond strength to sound dentine was found not to differ statistically from shear bond strength to sclerotic dentine whereas for hand-mixed cements, shear bond to sound dentine was found to be higher than to carious dentine (to at least p < 0.05). This shows that the chemical effects arising from interactions of glass-ionomer cements with the mineral phase of the tooth are the most important in developing strong bonds, at least in the shorter term.

Biomechanical Phenomena↗
PubMed2006

Characterization of a novel calcium phosphate composite bone cement: flow, setting, and aging properties.

The flow, setting, and aging characteristics of a newly developed calcium phosphate/calcium aluminate composite orthopaedic cement were studied. The effect of vibration on the flow of the cement paste was studied and found to greatly enhance placement. The setting times of this cement were dependent on temperature and decreased with increasing temperatures. At 37 degrees C, the working and setting times were 6.3 +/- 0.3 and 12.8 +/- 0.4 minutes, respectively. Hydration and conversion of the cement phases continued while specimens were stored under simulated, physiological conditions. A cumulative increase in mass of 8.23 +/- 0.65% was observed over a 14 month test period. During this time, the cement was found to expand slightly, 0.71 +/- 0.39%. X-ray diffraction was used to characterize the crystalline phases present during hydration and conversion. The calcium aluminate in the cement hydrated and formed calcium aluminate chloride hydrates, while no changes were observed in the beta-tricalcium phosphate during the testing period.

Bone Cements↗
PubMed1980

Comparison of orthodontic cements containing sodium fluoride or stannous fluoride.

A laboratory study was carried out to evaluate the effectiveness of NaF and SnF2, when incorporated into zinc oxyphosphate cement, in reducing the solubility and increasing the microhardness of human enamel. The control cement contained no added fluoride, and the test cements were prepared to contain fluoride concentrations of either 1,000, 2,000, or 4,000 ppm from each of the two test fluorides. SnF2-containing cement provided significantly (P < .01) greater solubility reduction at all three concentrations than did NaF cement. SnF2 was also more effective than NaF in rehardening enamel surfaces. SnF2 is thus much more effective than NaF when added to orthodontic cement. Current topical treatment literature, both laboratory and clinical, is in accord with this conclusion.

Dental Enamel↗
PubMed1981

Bond strength of cements to crown bases.

Amalgam crown bases provided more bond strength to cements than composite resin and cast gold. Modified zinc oxide-eugenol and polycarboxylate cements served better with composite resin bases. Modified zinc oxide-eugenol cement bonded to cast gold better than polycarboxylate and zinc phosphate cements. Polycarboxylate cement bonded to amalgam better than modified zinc oxide-eugenol and zinc phosphate cements. Amalgam was the material of choice for a crown base.

Composite Resins↗
PubMed1992

Effect of fluoride varnish on the retentive strength of provisional crowns luted with various temporary cements.

The retention of temporary crowns was studied with the use of a fluoride varnish (Duraphat) combined with various temporary cements. The mixture of Duraphat varnish and cement improved retention, with the exception of Opotow cement. Applying Duraphat varnish to the tooth surface before cementation enhanced the retentive strength of Tempbond, weakened the retention of Freegenol, but had no effect on Opotow cement. A "transfer effect" was observed, inasmuch as the Duraphat varnish encouraged adherence of the cement to the tooth structure rather than to the temporary crown.

Analysis of Variance↗
PubMed1992

The formation and properties of metal oxide poly(vinylphosphonic acid) cements.

Aqueous solutions of poly(vinylphosphonic acid) have been found to form polyelectrolyte cements with a wide range of metal oxides. Poly(vinylphosphonic acid), PVPA, has a structure similar to that of poly(acrylic acid), PAA, but contains pendant phosphonic acid,--P(O)(OH)2, groups in place of the carboxylic acid,--COOH, groups of the zinc polycarboxylate, and glass polyalkenoate cements. It is a stronger acid than PAA, with a greatly increased reactivity toward metal oxides. The physical and mechanical properties of a number of metal oxide PVPA cements were studied and compared with those of zinc polycarboxylate cements. The faster acting of the metal oxide PVPA cement seems to produce a cement that is less susceptible to early hydrolysis.

Dental Cements↗
PubMed1990

Dissolution mechanism of zinc phosphate dental cement in acetic and lactic acid buffers.

When zinc phosphate cement was immersed in 0.1 M acetic and lactic acid buffer solutions adjusted to pH 4.1, its dissolution rate was determined by chemical analysis. The eroded surface of the cement was examined by X-ray diffraction and SEM observation. The dissolution process of the cement immersed in the acetic acid buffer solution was mainly controlled by the diffusion of releasing species through the cement matrix and that of the cement immersed in the lactic acid buffer solution by the decomposition of the cement matrix at the surface.

Acetates↗
PubMed1994

Effect of methylene blue on the fracture toughness of acrylic bone cement.

It has been advocated that the use of contrast acrylic bone cement (namely, a cement in which a suitable additive is included) for the fixation of a cemented arthroplasty will facilitate its revision (should this be necessary). It is useful, therefore, to determine the extent to which each of the relevant mechanical properties of the cement is affected by the presence of such an additive. It is shown, in the present work, that the addition of one contrast agent (an aqueous methylene blue solution) to a cement has no statistically significant effect on its mode-I plane-strain fracture toughness. This strengthens the case for the use of contrast cement for the aforementioned application.

Acrylates↗
PubMed1992

Experimental studies of the biological response to a new bone cement: II Soft tissue reactions in the rat.

The biological response to a new bone cement (London Hospital cement), which contains polyethylmethacrylate/n-butylmethacrylate, has been examined experimentally and compared with polymethylmethacrylate. The cellular reaction was identical when the polymer powders of the cements were inserted subcutaneously in rats, there being a macrophage response to the polymer beads of both materials. Experimental implantation of the two cements into the paraspinal musculature of rats showed that there was less tissue damage adjacent to the new material than to polyethylmethacrylate. There was a significantly smaller macrophage and giant cell reaction in relation to the polyethylmethacrylate/n-butylmethacrylate cement. These differences may be related to the lower heat of polymerisation of the new cement and to its smoother surface contour, as demonstrated by scanning electron microscopy.

Animals↗
PubMed1994

A prospective study of a titanium femoral component for cemented total hip arthroplasty.

The authors studied the clinical and radiographic results of a modern titanium-alloy femoral stem with a cobalt-chrome-alloy head for use in cemented total hip arthroplasty. One hundred sixteen hips (102 patients) were operated on using modern cement techniques and prospectively followed using the Hospital for Special Surgery hip rating system and standard radiographic criteria. At a mean follow-up period of 4.8 years (range, 2-8 years), 69 hips were rated excellent, 38 good, 4 fair, and 5 poor. A total of 13 femoral components (11%) were radiographically loose according to the criteria of Harris. In 11 of these loose femoral components, debonding or separation at the cement-prosthesis interface, was the initial cause of failure, with bone-cement interface erosions occurring later in five hips. Revision of a loose femoral component has been performed in three hips and is pending in two other hips (4.3%). Significant calcar resorption was seen in only 17 hips (14.6%), and serial measurements of distal femoral cortical widths showed no distal cortical hypertrophy except in one femur. The incidence of loosening with this cemented titanium-alloy femoral component (with a cobalt-chrome-alloy head) is much higher than published reports of similar cobalt-chrome-alloy stems. The authors have abandoned the use of titanium-alloy femoral components for cemented total hip arthroplasty.

Adolescent↗
PubMed2005

Intravertebral cleft sign on fat-suppressed contrast-enhanced MR: correlation with cement distribution pattern on percutaneous vertebroplasty.

RATIONALE AND OBJECTIVES: Filling intravertebral clefts during percutaneous vertebroplasty (PVP) is considered to be important for optimal pain control. It is often difficult to detect clefts on non-contrast MR and some fractures show a solid pattern distribution of injected cement without a cleft sign on non-contrast MR. In this study, we evaluated usefulness of fat-suppressed contrast-enhanced MR to predict a solid pattern distribution of injected cement on PVP. MATERIALS AND METHODS: Twenty-six patients with 35 vertebral compression fractures due to osteoporosis were studied. We performed sagittal T1-weighted, T2-weighted and fat-suppressed contrast-enhanced T1-weighted images prior to PVP. First we evaluated the presence of fluid-filled or gas-containing clefts on non-contrast MR. Next we evaluated contrast-enhanced MR of the same vertebrae for the presence of cleft-shaped unenhanced areas within the diffuse enhancement area. We correlated MR findings with cement distribution patterns of injected cement. RESULTS: Based on MR findings, 35 osteoporotic fractures were divided into 3 types. Type 1 (11 fractures, 31%): There were no clefts on non-contrast MR and no unenhanced areas on contrast-enhanced MR; Type 2 (13, 37%): There were no clefts on non-contrast MR but there were unenhanced areas on contrast-enhanced MR; Type 3 (13, 37%): There were clefts on non-contrast MR and unenhanced areas on contrast-enhanced MR. Of 35 osteoporotic fractures, thirteen vertebral fractures (37%) were noted to contain clefts on non-contrast MR, while 24 vertebral fractures (69%) contained unenhanced areas on contrast-enhanced MR. Cement distributed as a solid pattern within clefts or unenhanced areas in all fractures with them. CONCLUSION: Fat-suppressed contrast-enhanced MR is useful to predict a solid pattern distribution of injected cement prior to PVP.

Aged↗
PubMed2006

Surface characterisation of various bone cements prepared with functionalised methacrylates/bioactive ceramics in relation to HOB behaviour.

This study reports the relationship between the biocompatibility and surface properties of experimental bone cements. The effect of hydroxyapatite (HA) or alpha-tri-calcium phosphate (alpha-TCP) incorporated into bone cements prepared with methyl methacrylate as base monomer and either methacrylic acid or diethyl amino ethyl methacrylate (DEAEMA) as comonomers was investigated. The in vitro biocompatibility of these composite cements was assessed in terms of the interaction of primary human osteoblasts grown on the materials over a period of 5 days and compared with a control surface. These results were related to the surface properties investigated through a number of techniques, namely Fourier transform infrared, contact angle measurements, X-ray photoelectron spectroscopy and energy dispersive analysis of X-rays. Complementary techniques of thermal analysis and ion chromatography were also performed. Biocompatibility results showed that the addition of alpha-TCP improves biocompatibility regardless of comonomer type. This is in contrast to HA-based cements where cell proliferation was significantly lower. Surface characterisations showed that structural integrity of the materials was maintained in the presence of the acid and base comonomers, and water contact angles were reduced particularly in DEAEMA containing materials. Furthermore, ion chromatography confirmed higher Ca2+ and PO4(3-) ion release by both types of ceramics, particularly for those containing DEAEMA. In conclusion, the incorporation of acidic and basic comonomers to either HA or alpha-TCP ceramics containing bone cements can have differential effects upon the attachment and proliferation of bone cells in vitro. Moreover, those cements consisting of alpha-TCP and containing DEAEMA comonomer indicated the most favourable biocompatibility.

Biocompatible Materials↗
PubMed2004

Mastering the art of cemented femoral stem fixation.

Cemented femoral stem fixation is reproducible and provides excellent early recovery of hip function in patients 60 to 80 years old. The durability of fixation has been evaluated up to 20 years with 90% survivorship. Achieving a uniform cement mantle and minimizing polyethylene wear has been shown to reduce the incidence of fixation failure. This article describes the senior author's (C.S.R.) technique for cemented total hip arthroplasty with particular emphasis on the art of cemented femoral stem fixation and his experience with 3 different cemented stem designs over 30 years. The results of using this cement technique with a modern stem design with a surface roughness of 30 to 40 microinches have produced a 95% survivorship at 10- to 20-year follow-up in patients 60 to 80 years old.

Aged↗
PubMed2006

Effect of pigmentation on the mechanical and polymerization characteristics of bone cement.

The impact on performance of additives to bone cement must be assessed before clinical use of the modified product. This study performed several standard acrylic bone cement tests on 3 commercially available products: Endurance, Surgical Simplex P, and Pigmented Endurance. The polymerization characteristics, consisting of doughing time, setting time, and maximum exothermic temperature, were found to be acceptable by the standards of the American Society for Testing and Materials/International Organization for Standards. For the mechanical characterization, analysis revealed statistical equivalence among all cement types, with the exception of compressive strength where Pigmented Endurance was stronger than Surgical Simplex P (P < .02). In mechanical fatigue, there were no significant differences in the log cycles to failure among the cements; however, Weibull analysis predicted Surgical Simplex P to have a higher characteristic life than the other cements. In conclusion, differences do exist among cement types, but the addition of pigment to Endurance did not alter its performance.

Biomechanical Phenomena↗