Factors associated with oral health-related quality of life in patients with diabetes.

BACKGROUND: Oral pathologies are prevalent in diabetes, and they may affect the quality of life and patient's perception of their oral health. The aim of this study was to investigate the factors associated with oral health-related quality of life of patients with diabetes. METHODS: A cross sectional study was conducted involving 316 patients visiting a hospital diabetic unit. Sociodemographic, oral and medical care data were recorded, and a General Oral Health Assessment Index (GOHAI) questionnaire was completed. A multivariable analysis was performed. RESULTS: Of the 316 study participants, 61.7% had type 2 diabetes (T2DM) and 20.5% had poorly controlled diabetes. Forty-five percent had at least one oral complication, 55% had visited a dentist within the past year and 67% reported having poor oral health and 281 answered the GOHAI questionnaire. A low GOHAI score (≤50) was obtained for 24.6% of the patients and was associated with T2DM, poorer oral health, dry mouth sensation and use of a removable prosthesis. CONCLUSIONS: Oral health status was poorer and had a negative effect on the quality of life among patients with T2DM, possibly contributing to poorly balanced nutrition.

Vertical bone regeneration with deproteinised bovine bone mineral or biphasic calcium phosphate in the rabbit calvarium: effect of autologous platelet lysate.

Although bone substitutes associated with platelet concentrates are widely used to vertically reconstruct alveolar ridges, their respective and specific contribution remain controversial. The aim of this study was to evaluate the benefit of using either biphasic calcium phosphate (BCP) or demineralised bovine bone mineral (DBBM) alone or with autologous platelet lysate (APL) in vertical bone regeneration. The study involved fourteen New Zealand rabbits. Autologous APL was prepared by freeze-thawing from a platelet suspension (10(9) platelets/ml). Four CP titanium (cpTi) cylinders were fixed to each calvarium; one cylinder was empty, one was filled with APL alone and the others were filled either with BCP or BCP + APL or DBBM or DBBM + APL. New bone formation and biomaterial resorption were evaluated using non-demineralised histology and histomorphometry. After 6 weeks, new bone formation was observed in all cylinders. The newly formed bone in the cylinders filled with APL alone, DBBM and BCP was significantly increased by (0.6-, 2.5- and 3.3-fold, respectively) (P < 0.0001) compared to results obtained with the empty cylinders. Vertical bone height in the cylinders filled with BCP was greater to that observed with DBBM. The residual material in the cylinders filled with BCP was significantly (P < 0.0001) lower (0.35-fold) than that with DBBM. Both newly formed bone and residual material in the cylinders filled with BCP + APL or DBBM + APL were similar to those filled with either BCP or DBBM, respectively. This study provided evidence that APL alone, as well as DBBM and BCP, have a beneficial effect on vertical bone formation and remodelling. APL associated with either DBBM or BCP did not provide additional benefits.

PolyNaSS grafting on titanium surfaces enhances osteoblast differentiation and inhibits Staphylococcus aureus adhesion.

Titanium surface modifications to simultaneously prevent bacterial adhesion but promote bone-cell functions could be highly beneficial for improving implant osseointegration. In the present in vitro study, the effect of sulfonate groups on titanium surfaces was investigated with respect to both S. aureus adhesion and osteoblast functions pertinent to new bone formation. Commercial pure titanium (cpTi) squares were oxydized (Tiox), grafted with poly(sodium styrene sulfonate) groups (Tigraft) by covalent bonding using radical polymerization, and were characterized by infrared spectroscopy (HATR-FTIR) and colorimetry. Bacterial adhesion study showed that Tigraft exhibited high inhibition of S. aureus adhesion S at levels >90 %, when compared to cpTi (P < 0.05). In contrast osteoblasts adhesion was similar on all three titanium surfaces. While the kinetics of cell proliferation were similar on the three titanium surfaces, Alkaline phosphatase-specific activity of osteoblasts cultured on Tigraft surfaces was twofold higher than that observed on either on Tiox or cpTi surfaces (P < 0.01). More importantly, the amount and the distribution of calcium-containing nodules was different. The total area covered by calcium-containing nodules was 2.2-fold higher on the Tigraft as compared to either Tiox or cpTi surfaces (P < 0.01). These results provide evidence that poly(sodium styrene sulfonate) groups grafting on cpTi simultaneously inhibits bacteria adhesion but promote osteoblast function pertinent to new bone formation. Such modified titanium surfaces offer a promising strategy for preventing biofilm-related infections and enhancing osteointegration of implants in orthopaedic and dental applications.

Bioactive polymer grafting onto titanium alloy surfaces.

Bioactive polymers bearing sulfonate (styrene sodium sulfonate, NaSS) and carboxylate (methylacrylic acid, MA) groups were grafted onto Ti6Al4V alloy surfaces by a two-step procedure. The Ti alloy surfaces were first chemically oxidized in a piranha solution and then directly subjected to radical polymerization at 70 degrees C in the absence of oxygen. The grafted surfaces were characterized by X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and the toluidine blue colorimetric method. Toluidine blue results showed 1-5microgcm(-2) of polymer was grafted onto the oxidized Ti surfaces. Grafting resulted in a decrease in the XPS Ti and O signals from the underlying Ti substrate and a corresponding increase in the XPS C and S signals from the polymer layer. The ToF-SIMS intensities of the S(-) and SO(-) ions correlated linearly with the XPS atomic percent S concentrations and the ToF-SIMS intensity of the TiO(3)H(2)(-) ion correlated linearly with the XPS atomic per cent Ti concentration. Thus, the ToF-SIMS S(-), SO(-) and TiO(3)H(2)(-) intensities can be used to quantify the composition and amount of grafted polymer. ToF-SIMS also detected ions that were more characteristic of the polymer molecular structure (C(6)H(4)SO(3)(-) and C(8)H(7)SO(3)(-) from NaSS, C(4)H(5)O(2)(-) from MA), but the intensity of these peaks depended on the polymer thickness and composition. An in vitro cell culture test was carried out with human osteoblast-like cells to assess the influence of the grafted polymers on cell response. Cell adhesion after 30min of incubation showed significant differences between the grafted and ungrafted surfaces. The NaSS grafted surfaces showed the highest degree of cell adhesion while the MA-NaSS grafted surfaces showed the lowest degree of cell adhesion. After 4 weeks in vivo in rabbit femoral bones, bone was observed to be in direct contact with all implants. The percentage of mineralized tissue around the implants was similar for NaSS grafted and non-grafted implants (59% and 57%). The MA-NaSS grafted implant exhibited a lower amount of mineralized tissue (47%).

Bone tissue response to titanium implant surfaces modified with carboxylate and sulfonate groups.

The present study assessed in vivo new bone formation around titanium alloy implants chemically grafted with macromolecules bearing ionic sulfonate and/or carboxylate groups. Unmodified and grafted Ti-6Al-4V exhibiting either 100% carboxylate, or 100% sulfonate, or both carboxylate and sulfonate groups in the percent of 50/50 and 80/20 were bilaterally implanted into rabbit femoral condyle. Neither toxicity nor inflammation were observed for all implants tested. After 4 weeks, peri-implant new bone formation varied as a function of the chemical composition of the titanium surfaces. The percent bone-implant contact (BIC) was the lowest (13.4 +/- 6.3%) for the implants modified with grafted carboxylate only. The value of BIC on the implants with 20% sulfonate (24.6 +/- 5.2%) was significantly (P < 0.05) lower than that observed on 100% sulfonate (38.2 +/- 13.2%) surfaces. After both 4 and 12 weeks post-implantation, the BIC value for implants with more than 50% sulfonate was similar to that obtained with the unmodified Ti-6Al-4V. The grafted titanium alloy exhibiting either 100% sulfonate or carboxylate and sulfonate (50% each) groups promoted bone formation. Such materials are of clinical interest because, they do not promote bacteria adhesion but, they support new bone formation, a condition which can lead to osseointegration of bone implants while preventing peri-implant infections.

Effects of autologous platelet lysates on ceramic particle resorption and new bone formation in critical size defects: the role of anatomical sites.

This study investigated the effects of rabbit autologous platelet lysates (APL) on the performance of fillers consisting of calcium carbonate ceramic particles (CP) pertinent to new bone formation and repair. Critical-size defects in rabbit femurs and calvaria were filled with CP alone, CP plus APL, and CP plus APL with or without thrombin (THR). After 6 weeks, resorption of CP occurred under all conditions tested in the present study. Compared with respective CP alone controls, addition of APL resulted in significantly higher ceramic resorption, as evidenced by decreased ceramic particle diameter (p < 0.01) and number (p < 0.01) at both defect sites. The presence of THR prevented reduction of both CP diameter and number in the femoral defect sites. Addition of APL to the CP resulted in a significant (p < 0.03) decrease in new bone area at the calvarial sites, but not at the femoral sites; moreover, when THR was added to the CP plus APL fillers, bone formation in the femoral defects was significantly (p < 0.05) reduced. In addition to differences in the respective anatomical and cellular milieu, the biochemical events induced by mechanical loading at the femurs may explain the reduced ceramic particle resorption as well as the enhanced new bone formation when compared with the results obtained at the calvarial defect sites.

Engineering bone: challenges and obstacles.

Repair of large bone defects is still a challenge for the orthopaedic, reconstructive and maxillo-facial surgeon. Availability of pluripotent stem cells from either autologous or allogenic sources and the potential of inducing the osteogenic phenotype is motivating exploration and development of custom-tailored materials known as "bioengineered bone constructs". In such cases, the clinical scenario involves either expansion of stem cells in monolayer and loading them into a porous scaffold prior to surgery or direct cell expansion within the scaffold, and implanting this novel construct back into the donor patient. In this review, we delineate, from an engineering perspective, the progress that has been made to date and the challenges remaining in successfully translating this promising (but not yet definitively established) approach from bench to the bed site.

Phenotypic characterization of the 3/A/1D-1M osteogenic cell line derived from in vivo transplantation of 3/A/1D-1 chondroprogenitor murine teratocarcinoma cells.

Bone cells involved in the replacement of cartilage by bone in the endochondral ossification process are known to enter via the medullar pathway. A hypothesis for the development of osteoblasts from chondroblasts was investigated by analyzing the phenotypic characteristics of the 3/A/1D-1M cell line derived from endochondral bone ossicle which was formed after in vivo transplantation of 3/A/1D-1 chondroprogenitor mouse teratocarcinoma cells. The 3/A/1D-1M cell cultures exhibited a triphasic evolution: after reaching confluence (day 3), cultures developed well-delimited cell clusters (days 6-8), which ultimately were organized into multilayered nodules (days 12-15). Electron-microscopic examination of such nodules at day 18 showed the presence of needle-shaped crystals associated with collagen fibrils in the extracellular space. The kinetics of collagen expression, investigated by an immunofluorescence staining procedure showed that, while confluent cultures mainly expressed type III collagen (70% of cells) with some type I (30-40% of cells) and V (30-40% of cells), the type I collagen became the major isoform beginning with day 6. From day 6 onwards, NP40-extracted alkaline phosphatase (AP) activity appeared concomitantly to cell cluster formation, and reached 160 nmol/min/mg of protein at the stage of nodule maturation (day 15). The strong inhibition of enzymatic activity by levamisole and L-homoarginine (IC50 = 0.9 microM and 5 mM, respectively) and its rapid heat inactivation at 56 degrees C (IT50 = 90 s), revealed the bone specificity of AP expressed by 3/A/1D-1M cells. In confluent cultures, brief exposure to parathyroid hormone (10 nM), known to be a bone-resorbing agent, showed a 60% increase in the intracellular cAMP level. In addition, while producing mRNA for the bone-specific protein osteocalcin, 3/A/1D-1M cells also produced type II procollagen mRNA, known to be the major cartilage-related characteristic. This in vitro study demonstrates that the 3/A/1D-1M clonal cell line, originating from 3/A/1D-1 chondroprogenitor cells after in vivo passage, was able to develop differentiated osteoblastic properties as well as the residual expression of the major chondrocytic RNA messenger.

Role of beta-GP-derived Pi in mineralization via ecto-alkaline phosphatase in cultured fetal calvaria cells.

The permissive effect of beta-GP on mineralization in cultured rat fetal calvaria cells was investigated in relationship with phosphohydrolase activity of ecto-ALP at physiological pH range. Beta-GP present in the culture medium for 8 days exerted a stimulatory effect on 45Ca incorporation into matrix cell layers while the ecto-ALP activity level measured on intact cells with a saturating concentration of pNPP was similar for cells grown either in the presence or absence of beta-GP. In both types of cultures, beta-GP addition inhibited pNPP hydrolysis in a competitive and reversible manner and increased Pi concentration in the medium. The dose dependency of the effect of beta-GP on 45Ca incorporation and generation of Pi was similar (k phi = 3 mM). Levamisole, but not dexamisole, inhibited both pNPP and beta-GP hydrolyses, which were likely catalyzed by the same ecto-enzyme. The rate of 45Ca incorporation into matrix cell layers, which was high (0.90 mumol/4h/mg cell protein) in cells grown in the absence of beta-GP, was inhibited by 50% by levamisole. In cells grown in the absence of beta-GP, the 45Ca incorporation rate increased progressively after beta-GP addition, reaching after 12 h the value of cultures grown in the presence of beta-GP, the increase being totally inhibited by levamisole. In both types of cells, addition of exogenous Pi at concentrations corresponding to medium levels of beta-GP-derived Pi rapidly led to high 45Ca incorporation rate which was unaffected by levamisole. beta-GP removal from cultures grown in its presence reduced by 50% the 45Ca incorporation rate which recovered the initial value after exogenous Pi addition independently of levamisole presence. Thus, mineral deposition did not affect the level and catalytic efficiency of ecto-ALP to hydrolyze beta-GP in cultured fetal calvaria cells, yet it influenced the beta-GP-stimulatory effect on mineralization so as to render this process not sensitive to high medium Pi levels.

Ecto-alkaline phosphatase considered as levamisole-sensitive phosphohydrolase at physiological pH range during mineralization in cultured fetal calvaria cells.

Alkaline phosphatase (ALP) activity expressed on the external surface of cultured fetal rat calvaria cells and its relationship with mineral deposition were investigated under pH physiological conditions. After replacement of culture medium by assay buffer and addition of p-nitrophenyl phosphate (pNPP), the rate of substrate hydrolysis catalyzed by whole cells remained constant for up to seven successive incubations of 10 min and was optimal over the pH range 7.6-8.2. It was decreased by levamisole by a 90% inhibition at 1 mM which was reversible within 10 min, dexamisole having no effect. Values of apparent Km for pNPP were close to 0.1 mM, and inhibition of pNPP hydrolysis by levamisole was uncompetitive (Ki = 45 microM). Phosphatidylinositol-specific phospholipase C (PI-PLC) produced the release into the medium of a p-nitrophenyl phosphatase (pNPPase) sensitive to levamisole at pH 7.8. The released activity whose rate was constant up to 75 min represented after 15 min 60% of the value of ecto-pNPPase activity. After 75 min of PI-PLC treatment the ecto-pNPPase activity remained unchanged despite the 30% decrease in Nonidet P-40-extractable ALP activity. High levels of 45Ca incorporation into cell layers used as index of mineral deposition were decreased by levamisole in a stereospecific manner after 4 h, an effect which was reversed within 4 h after inhibitor removal, in accordance with ecto-pNPPase activity variations. These results evidenced the levamisole-sensitive activity of a glycosylphosphatidylinositol-anchored pNPPase consistent with ALP acting as an ecto-enzyme whose functioning under physiological conditions was correlated to 45Ca incorporation and permit the prediction of the physiological importance of the enzyme dynamic equilibrium at the cell surface in cultured fetal calvaria cells.