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PubMed2002

Palliative occipito-cervical stabilization in patients with malignant tumors of the occipito-cervical junction and the upper cervical spine.

BACKGROUND: Occipital-cervical stability may be impaired in patients with primary malignant or metastatic tumors of the cranio-cervical junction and the upper cervical spine. The purpose of this study was to evaluate occipital-cervical fixation with pre-bent titanium-loops and sublaminar wiring in order to achieve a rigid and safe stabilisation of the occipito-cervical region in this group of patients. METHOD: 20 patients with severe impairment of occipito-cervical stability due to primary malignant or metastatic cervical bone involvement were included in this study. For palliation of symptoms, resulting from destructive instability, a stabilization procedure using Ransford Loops with sublaminar cable fixation was used in these patients as a palliative therapeutic concept. FINDINGS: Pain which was the major symptom in all patients treated, showed good and immediate response to the stabilization procedures. All 20 patients were either pain free or had good improvement with less intake of analgesic drugs. Signs of spinal cord compression like spasticity and quadraparesis were less likely to improve after surgery. However in 3 of 5 patients neurological function improved after surgery whereas in 2 patients no improvement was achieved. INTERPRETATION: In all patients with impaired occipito-cervical stability due to primary malignant or metastatic tumors of the occipito-cervical junction and the upper cervical spine, immediate stabilization resulting in an improvement of pain was achieved. Occipito-cervical stabilization using contoured Ransford loops is a promising palliative therapeutic concept in this group of patients.

Adult↗
PubMed2002

Stabilities of lead(II) complexes formed in aqueous solution with methyl thiophosphate (MeOPS(2-)), uridine 5'- O-thiomonophosphate (UMPS(2-)) or adenosine 5'- O-thiomonophosphate (AMPS(2-)).

The acidity constants of twofold protonated methyl thiophosphate (MeOPS(2-)) and of monoprotonated uridine 5'- O-thiomonophosphate (UMPS(2-)) have been determined in aqueous solution (25 degrees C; I= 0.1 M, NaNO(3)) by potentiometric pH titration. The stability constants of their 1:1 complexes formed with Pb(2+), i.e. Pb(MeOPS) and Pb(UMPS), have also been measured. The results show that replacement of a phosphate oxygen by a sulfur atom increases the acidity by about 1.4 p K units. On the basis of recently established log versus plots ( = simple phosphate or phosphonate ligands where R is a non-coordinating residue), it is shown that the stability of the Pb(thiophosphate) complexes is by log Delta= 2.43+/-0.09 larger than expected for a Pb(2+)-phosphate interaction. The identity of the stability increase (log Delta) observed for Pb(MeOPS) and Pb(UMPS) shows that the nucleobase residue in the Pb(UMPS) complex has no influence on complex formation. To be able to carry out the mentioned comparisons, we have also determined the stability constant of the complex formed between Pb(2+) and methyl phosphate; the corresponding data for Pb(UMP) were already known from our earlier studies. The present results allow an evaluation of other Pb(2+) complexes formed with thiophosphate derivatives and they are applied now to the Pb(2+) complexes of adenosine 5'- O-thiomonophosphate (AMPS(2-)). The stability constants of the Pb(H;AMPS)(+) and Pb(AMPS) complexes were measured and it is shown that, within the error limits, the stability of the Pb(AMPS) complex is determined by the basicity of the thiophosphate group of AMPS(2-); in other words, no hint for macrochelate formation involving N7 was observed. More important, with the aid of micro-stability-constant considerations it is concluded that the structure of the dominating isomer of the Pb(H;AMPS)(+) species is the one where the proton is located at the N1 site of the adenine residue and Pb(2+) is coordinated to the deprotonated thiophosphate group. The insights gained from this study with regard to thiophosphate-altered single-stranded nucleic acids and their affinity towards Pb(2+) are discussed.

Adenosine Monophosphate↗
PubMed1987

Characterization of the in vitro stability of the rat hepatic receptor for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).

The in vitro stability of the Ah receptor from rat hepatic cytosol was evaluated by [3H]TCDD binding studies, gel filtration, and sucrose density gradient ultracentrifugation. Thermal inactivation of unoccupied receptor followed first-order kinetics between 5 and 40 degrees C, with an estimated Ea for inactivation of approximately 35 kcal/mol. Protease inhibitors did not reduce and dilution slightly increased the inactivation rate at 20 degrees C. Recovery and 20 degrees C stability decreased with increasing ionic strength. The TCDD-receptor complex was less susceptible to degradation at 20 degrees C, even in the presence of 0.4 M KCl. Specific binding was markedly pH dependent, with maximum recovery at 7.6. Analysis of the pH curve suggested that cysteine sulfhydryl groups may be involved in TCDD binding. Dithiothreitol (1 mM) maximized recovery and 20 degrees C stability, and addition of the thiol largely reactivated binding sites lost from cytosol prepared without it. Removal of low molecular weight components of cytosol by gel filtration resulted in a rapid 20 degrees C inactivation rate that could not be lessened by dithiothreitol. Glycerol (10% v/v) and EDTA (1.5 mM) maximized recovery of specific binding, but both decreased 20 degrees C stability in a concentration-dependent manner. Calcium chloride (4 mM) increased stability at 20 degrees C by approximately 20%, and retarded the characteristic shift in sedimentation coefficient from approximately 9 to approximately 6 S in high-salt sucrose gradients. The fact that sodium molybdate (20 mM) decreased recovery and 20 degrees C stability when dithiothreitol was present but slightly increased stability in its absence suggested an antagonism between the two compounds. Molybdate mitigated the inactivation induced by 0.4 M KCl, an effect which may be related to the observation of dual peaks in molybdate-containing high-salt sucrose gradients. These data indicate that thermal inactivation of the unoccupied rat hepatic Ah receptor primarily may be due to physical rather than enzymatic processes; (ii) sulfhydryl oxidation, removal of low molecular weight cytosolic components, and high ionic strength result in rapid rates of inactivation at 20 degrees C; and (iii) the large degree of protection conferred by TCDD binding implies a very tight ligand-receptor interaction, and as such accords with TCDDs extraordinary potency and persistence in producing its toxic and biochemical effects.

Animals↗
PubMed1991

Improved stability of rabbit and rat intestinal brush border membrane vesicles using phospholipase inhibitors.

The initial rates of Na(+)-dependent D-aspartate and D-glucose uptakes were shown to decline from the time of resuspension of brush border membrane vesicles isolated from rabbit and rat jejunum by standard divalent cation precipitation procedures. The former were however more stable than the latter and followed quite closely the decrease in the intravesicular volume, thus suggesting that the loss of transport activity may involve both nonspecific opening of the vesicles and either direct or indirect specific inactivation of the transporters. Uptake rates for both substrates did tend to stabilize at 6-24 h from resuspension, however this final 'next day' uptake activity was too low to be of practical use in kinetic studies. Freezing aliquots of rabbit jejunal vesicles in liquid N2 until the time of assay resulted in complete stabilization of D-glucose uptake. A modified homogenate buffer designed to inhibit a broad spectrum of phospholipase activities resulted in a partial stabilization of glucose transport by rabbit jejunal vesicles with, on average, an over 6-fold enrichment in the 'next day' stable specific activity of uptake as compared to unfrozen vesicles. The modified homogenate buffer also improved the stability and the 'next day' specific activities of D-glucose uptake in rat jejunal brush border vesicles and D-aspartic acid uptake in rabbit jejunal vesicles. It also completely stabilized the intravesicular volume in the latter preparation. An evaluation of the kinetic parameters of Na(+)-dependent D-glucose transport in rabbit vesicles prepared from either the standard homogenate media and frozen in liquid N2 or the modified media and allowed to stabilize overnight, revealed a single transport system with a Km of 0.31-0.32 mM as the best model to fit the data. As such the modifications to the homogenate media do not appear to effect the functional properties of D-glucose transport in the membrane. While being less efficient in stabilizing the vesicles than the rapid freezing protocol, it is shown that the modified homogenate should however be preferred when dealing with slowly permeant ions like choline since it provides in this case the only alternative to reliable measurement of uptake rates across a stable and equilibrated vesicle preparation.

Animals↗
PubMed1995

Tradeoffs between motion and stability in posterior substituting knee arthroplasty design.

The purpose of this study was to examine how changes in component geometry of posterior substituting knees affect tibiofemoral kinematics and prosthesis stability. Most posterior cruciate ligament substituting prostheses rely on an articulation between a femoral cam and tibial spine to provide anterior-posterior stability of the knee. Failure of this ligament substitution mechanism has resulted in knee dislocations with several different posterior substituting designs. A computer model of a generic posterior substituting prosthesis was altered to analyze the effects of five design parameters (tibial spine height, spine anterior-posterior position, femoral component posterior radius, and femoral cam anterior-posterior and distal-proximal position) on prosthesis stability, tibiofemoral kinematics, and maximum obtainable knee flexion. Prosthesis stability was characterized by a 'dislocation safety factor', defined as the vertical distance from the bottom of the femoral cam to the top of the tibial spine. Computer simulations revealed that posterior substituting knees are most likely to dislocate at maximum knee flexion. Prosthesis stability can be improved by increasing the tibial spine height and moving the femoral cam posteriorly. Our results suggest there is a tradeoff between maximum knee flexion and prosthesis stability. We found that relatively small gains in maximum knee flexion, made through design changes, may cause substantial decreases in prosthesis stability.

Arthrography↗
PubMed1988

Erythromycin-induced stabilization of ermA messenger RNA in Staphylococcus aureus and Bacillus subtilis.

Erythromycin-induced stabilization of ermA mRNA was studied in Staphylococcus aureus, its original host background, and in Bacillus subtilis, subcloned on plasmid vectors. By RNA blot analysis it was shown that 40 nM-erythromycin specifically increased the chemical half-life of ermA mRNA from 2.5 to 17.5 minutes whereas the half-life of cat-86 mRNA was not increased by erythromycin. While expression of ermA has been shown to be induced by erythromycin at the level of translation, our studies with three ermA constitutive mutants demonstrated that mRNA stabilization in growing cells occurred independently of induced gene expression, suggesting that the stabilized mRNA was not functional for protein synthesis. Studies of ermA/lacZ fusions demonstrated that the 5' end of the mRNA was sufficient to confer stabilization. Translation of specific amino acid codons in a leader peptide located at the extreme 5' end of the mRNA was required for the erythromycin-induced stabilization as a frameshift mutation introduced into the leader peptide determinant abolished stabilization. By S1 mapping, no differences were detected in the length of the 5' or 3' end of ermA mRNA with the addition of erythromycin, indicating that the stabilized transcript was not processed at its ends.

Bacillus subtilis↗
PubMed1983

The thermal lability of adenylate cyclase: mechanisms of stabilization.

The thermal inactivation of adenylate cyclase was investigated in human lymphocytes and in the N-protein deficient cyc- S49 mouse lymphoma cell line. The enzyme is rapidly inactivated at 37C with a t1/2 of 5.5 and 4.5 min respectively in human and cyc- membranes. Thermal inactivation is prevented by at least two mechanisms. The first mechanism involves ATP which stabilizes adenylate cyclase in a concentration dependent manner similar to the Km of ATP for cAMP formation. However, the inhibition of inactivation does not require Mg++ while the enzyme catalysis of ATP to cAMP does. The second mechanism involves substances which activate the enzyme. The human lymphocyte enzyme is equally stabilized by either NaF, GppNHp, or forskolin. In contrast, the cyc- enzyme is fully stabilized by forskolin but only partially stabilized by NaF. When human erythrocyte N-protein extract is added to cyc- membranes, NaF fully stabilizes the enzyme. These data suggest that an activated N-protein is instrumental in stabilizing adenylate cyclase and that there is some N-protein component in cyc- membranes through which NaF may be exerting its stabilizing action.

Adenosine Triphosphate↗
PubMed1992

Determinants of rotavirus stability and density during CsCl purification.

The stability of rotavirus infectivity during CsCl gradient purification and subsequent storage was examined using our standard SA11 wild type (SA11-Cl3), the SA11 4F variant (SA11-4F), bovine rotavirus B223, and a panel of bi- and triparental reassortants derived from these parental viruses. Viral stability was determined by the recovery of infectivity at each step during a standard CsCl purification protocol. SA11-4F was the most stable parent (91-93% recovery), SA11-Cl3 had intermediate stability (10-21% recovery), and B223 was least stable (0.5-7% recovery). Among the reassortants, the recovery varied from 0.5 to 88.6% of the initial infectivity and was determined primarily by the parental origin of genome segment 4. The greatest loss of infectivity occurred during Freon extraction, with smaller losses during the CsCl gradient, and the smallest loss during the virus pelleting step. Comparison of the stability of viruses grown in the presence or absence of exogenous trypsin revealed that, in general, viruses grown in the absence of trypsin were more stable during purification. During 4-5 months storage at 4 degrees, the differences in stability of parental and reassortant viruses were not as dramatic as during purification and were not significantly affected by the presence or absence of trypsin during growth. However, survival during storage was as low as 4% and as high as 100% and was also primarily dependent on the parental origin of genome segment 4. It was noted that bovine rotavirus B223 had higher density in CsCl than either SA11-Cl3 or SA11-4F. The observation of heterogeneity in density was investigated using reassortants. These results indicated that all reassortants had intermediate density and suggested that physical interactions among the structural proteins were responsible for the heterogeneity in density. The possible roles of viral structural proteins in rotavirus stability and the relationship between the stability and the density are discussed.

Centrifugation, Density Gradient↗
PubMed1992

Stability of p53 protein in rat cells transformed by various viral transforming genes.

To clarify the correlation between metabolic stabilization of p53 protein and cellular transformation, we transformed the normal rat cell line F2408 with various viral transforming genes and examined the expression and stability of p53 protein in these transformed cells by pulse-chase immunoprecipitation experiments. As expected, the level of p53 in the SV40-transformed rat cell line was higher than that in the normal cell line and its stability was also increased. In contrast, in cells transformed with the E7 and E6 genes of human papillomavirus type 16, the level and stability of p53 were similar to those in the normal cells. In cells transformed by the middle T or large T of polyomavirus, v-K-ras, and v-src, the levels and stabilities of p53 were also not elevated, although the level of p53 was increased in activated c-H-ras-transformed cells without an increase in its stability. These results show that increased stability and expression of the p53 protein are not common events in viral transformation of the rat cell line. In addition, we demonstrated with a monoclonal antibody specific for the mutant form of p53 that cellular transformation by viral transforming genes does not involve mutational activation of p53 to an oncogenic form.

Animals↗
PubMed1983

Use and possibilities for substitution of cadmium stabilizers.

Of all plastics, Polyvinyl chloride is the only product stabilized with cadmium compounds, and then only to a certain extent. The amount of cadmium used as stabilizers is approximately 15% of the world production. The general importance of stabilization in view of ecotoxicological problems is discussed, leading to a more detailed consideration of the specific sectors in which plastic materials are used. Stabilization is strongly connected with the intended application and processing technology. It is obvious that stabilization of rigid PVC is indispensable in outdoor applications. If, at present, no substitute for cadmium stabilization is available, it is emphasized that the industry is strongly interested in resolving the problem, i.e., in searching for a cadmium-free stabilizer, for economic as well as environmental reasons.

Cadmium↗
PubMed1995

Temporal stability of children's cardiovascular (CV) reactivity: role of ethnicity, gender and family history of myocardial infarction.

Cardiovascular responses to three laboratory stressors (i.e., postural change, treadmill exercise, forehead cold) were evaluated in 106 children (72 Whites, 34 Blacks) who varied in family history (FH) of early myocardial infarction (53 positive FH, 53 negative FH). Subjects were evaluated on two occasions separated by one year. In general, regardless of ethnicity, gender or FH, stability of resting blood pressures (BP) and heart rates were comparable to existing data. Resting cardiac output (CO) and total peripheral resistance (TPR) stability estimates were comparable or higher than the BP estimates across groups except for the +FH subjects and males who showed poor stability to one or both parameters. Moderate stability was observed for all parameters in response to forehead cold and low to moderate stability was observed in HR, CO, and TPR postural change reactivity. The only consistent pattern of significant differences in stability estimates involved ethnicity. African-Americans exhibited significantly higher coefficients compared to Whites in TPR at rest and during postural change and forehead cold. Reasons for the low to moderate resting and reactivity stability estimates are discussed.

Black People↗
PubMed1991

Stability patterns and trophic structure in a Delaware Bay plankton community.

Using qualitative loop analysis we have extended our examination of a Delaware Bay plankton community to include an investigation of the roles played by the various entities (population, guild or nutrient) in the community. In an entity removal exercise, we used stability relationships as a probe into community structure. Six types of stability change are possible as a result of entity removal from the system: stable to stable (s-->s); stable to unstable (s-->u); stable to disconnected (s-->d); unstable to stable (u-->s); unstable to unstable (u-->u); unstable to disconnected (u-->d). Using these changes as an investigative tool, we found that in order to account for the stability-instability patterns, it was necessary to construct a refined trophic structure model. The observed connections between the entities in the larger model could be grouped into two different types of stability substructures: a simple pattern and a more complex branching pattern. These patterns map easily onto the refined trophic structure model. Using stability analysis it is also possible to model community structure in ways other than the traditional trophic approach. Patterns of system necessity and relative contribution to stability are observed. These patterns match the refined trophic structure model derived previously. The roles that the various entities play in the overall community were followed over an annual cycle. Entities were seen to change their roles as a function of time and status within a subgroup. These results show that stability determinations have the potential to be used as a valuable tool in community analysis.

Animals↗
PubMed1992

The effects of scaphoid intercarpal stabilizations on wrist mechanics: an experimental study.

A fresh cadaver study of the effects of a variety of scaphoid stabilizations on wrist motions is reported. Scaphoid-trapezium-trapezoid stabilizations with the scaphoid in its normal anatomic position and the same stabilizations with the scaphoid in malposition, either vertical or horizontal in relation to the radius, were compared. Scaphoid-capitate stabilizations with the scaphoid in its normal position were also studied. With the scaphoid vertical, a scaphoid-trapezium-trapezoid stabilization resulted in greater loss of wrist flexion and ulnar deviation whereas, with the scaphoid horizontal, wrist extension and radial deviation were more severely affected than when the scaphoid was stabilized in its normal position. With the scaphoid in its anatomic position, both scaphoid-trapezium-trapezoid and scaphoid-capitate stabilizations resulted in similar patterns of wrist motion.

Bone Nails↗
PubMed1992

Stability of press-fit acetabular cups.

Mechanical tests were performed to characterize the initial stability of press-fit cups as a function of cup design, surface structure, and surgical preparation. Eight cups from six manufacturers were press-fit into acetabular cavities prepared in two densities of Sawbones polyethylene foam and in bovine knee trabecular bone. Cavity sizes and cup loading forces were varied. Acetabular defects were simulated in the Sawbones model. Preparations were tested to determine axial-rotatory and tangential ("levering-out") stability. Results suggested that cup geometry and proper surgical technique--in particular, proper sizing and depth of the acetabular cavity--are important in determining initial cup stability independent of adjuvant screw or spike fixation. Stability is a function of the area of interface contact between the cup rim and the substrate. If the cavity is too small or too shallow, and the substrate too dense, the cup will not seat to the rim and stability will be compromised. If there are defects in the rim, the area of interface contact will be diminished and stability compromised. Cups with a true hemispherical design have a greater area of rim interface contact than "low-profile" cups and are therefore more stable. 1 mm undersizing of the cavity (or 2 mm undersizing in less dense substrate) appears to provide optimal stability.

Acetabulum↗
PubMed1995

Construction of a functional disulfide-stabilized TCR Fv indicates that antibody and TCR Fv frameworks are very similar in structure.

Disulfide-stabilized Fvs (dsFv) are recombinant Fv fragments of antibodies in which the inherently unstable VH-VL heterodimer is stabilized by an interchain disulfide bond engineered between structurally conserved framework positions. We now design and produce a disulfide-stabilized Fv of a T cell receptor. It is composed of V alpha and V beta variable domains of the 2B4 TCR stabilized by a disulfide bond between framework residues of the TCR Fv at a site corresponding to that used for disulfide stabilization of antibody Fvs. For ease of production and detection, the TCRdsFv was fused to a truncated form of Pseudomonas exotoxin (PE38). The TCR(dsFv) retains its native conformation and is much more stable than a TCR scFv. Moreover, it is functional in biological assays. Because successful disulfide stabilization of the TCR Fv by the positions used for antibody Fv stabilization would not occur unless the mutated residues in TCR Fv are at positions closely similar to those in antibody Fvs, most likely within less than 1.5 A, these results provide very strong experimental evidence for the structural similarity between immunoglobulin and TCR antigen-binding variable domains.

Amino Acid Sequence↗
PubMed2006

Effects of lumbar stabilization using a pressure biofeedback unit on muscle activity and lateral pelvic tilt during hip abduction in sidelying.

OBJECTIVE: To assess the effects of lumbar spine stabilization using a pressure biofeedback unit on the electromyographic activity and angle of lateral pelvic tilt during hip abduction in a sidelying position. DESIGN: Comparative, repeated-measures study. SETTING: University research laboratory. PARTICIPANTS: Eighteen able-bodied volunteers (9 men, 9 women) with no history of pathology. INTERVENTION: Subjects were instructed to perform hip abduction in a sidelying position in both the preferred hip abduction (PHA) and hip abduction with lumbar stabilization (HALS). A pressure biofeedback unit was used for lumbar stabilization. MAIN OUTCOME MEASURES: Surface electromyography was recorded from the quadratus lumborum, gluteus medius, internal oblique, external oblique, rectus abdominis, and multifidus muscles. Kinematic data for lateral pelvic tilt angle were measured using a motion analysis system. Dependent variables were examined with 2 (PHA vs HALS) x 2 (men vs women) analysis of variance. RESULTS: Significantly decreased electromyographic activity in the quadratus lumborum (PHA, 60.39% +/- 15.62% of maximum voluntary isometric contraction [MVIC]; HALS, 27.90% +/- 13.03% of MVIC) and significantly increased electromyographic activity in the gluteus medius (PHA, 25.03% +/- 10.25% of MVIC; HALS, 46.06% +/- 21.20% of MVIC) and internal oblique (PHA, 24.25% +/- 18.10% of MVIC; HALS, 44.22% +/- 20.89% of MVIC) were found when the lumbar spine was stabilized. Lateral pelvic tilt angle (PHA, 13.86 degrees +/- 4.66 degrees; HALS, 5.55 degrees +/- 4.16 degrees) was decreased significantly when the lumbar spine was stabilized. In women the electromyographic activity (percentage of MVIC) in gluteus medius, external oblique, and rectus abdominis was significantly higher than that observed in men. CONCLUSIONS: With lumbar stabilization, the gluteus medius and internal oblique activity was increased significantly, and the quadratus lumborum activity was decreased significantly, causing reduced lateral pelvic tilt in a sidelying position. These results suggest that hip abduction with lumbar stabilization is useful in excluding substitution by the quadratus lumborum.

Adult↗
PubMed2007

Quantification of lumbar stability by using 2 different abdominal activation strategies.

OBJECTIVE: To determine whether the abdominal hollowing technique is more effective for lumbar spine stabilization than a full abdominal muscle cocontraction. DESIGN: Within-subject, repeated-measures analysis of variance was used to examine the effect of combining each of 4 loading conditions with either the hollow or brace condition on the dependent variables of stability and compression. A simulation was also conducted to assess the outcome of a person activating just the transversus abdominis during the hollow. SETTING: Laboratory. PARTICIPANTS: Eight healthy men (age range, 20-33y). INTERVENTIONS: Electromyography and spine kinematics were recorded during an abdominal brace and a hollow while supporting either a bilateral or asymmetric weight in the hands. MAIN OUTCOME MEASURES: Spine stability index and lumbar compression were calculated. RESULTS: In the simulation "ideal case," the brace technique improved stability by 32%, with a 15% increase in lumbar compression. The transversus abdominis contributed .14% of stability to the brace pattern with a less than 0.1% decrease in compression. CONCLUSIONS: Whatever the benefit underlying low-load transversus abdominis activation training, it is unlikely to be mechanical. There seems to be no mechanical rationale for using an abdominal hollow, or the transversus abdominis, to enhance stability. Bracing creates patterns that better enhance stability.

Abdominal Muscles↗
PubMed2006

The influence of surface coatings of dicalcium phosphate (DCPD) and growth and differentiation factor-5 (GDF-5) on the stability of titanium implants in vivo.

Mechanical stability of implants is usually tested by pull out or push out tests which destroy the interface between the implant and bone. Pull out tests do not ideally reflect the clinical situation. In contrast, applying submaximal load leads to more physiologic micro-displacement between implant and bone. The aim of this study was to evaluate a new non-destructive mechanical testing device on different modifications of titanium implants. In 18 rabbits we investigated the influence of a dicalcium phosphate (DCPD) coating, or of a growth and differentiation factor-5 (GDF-5) coating, or a combination of both on the stability of titanium implants. The stability of implant was assessed by a non-destructive micro-measurement. In the same specimens the interface was investigated by micro-CT and histological evaluation. Surface modifications had a positive effect on the implant stability regarding displacement (p=0.001). Mechanical stability correlated with the quality of peri-implant tissue. Micro-displacement correlated negatively with the bone formation around the implants in histomorphometric evaluation (p=0.02). Amount of peri-prosthetic soft tissue showed a positive correlation with micro-displacement (p=0.01). Our findings indicate the positive effect of DCPD and GDF-5 coatings on stability of titanium implants. Results demonstrate the non-destructive testing to be an effective method to evaluate mechanical stability of implants.

Adhesiveness↗