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This prospective multicentre study provides clinical experience up to 3 years to support a simplified treatment for mandibular edentulism within 1 week by using one-stage implant surgery and a screw-retained full-arch bridge.Two hundred and fifty ITI MonotypeFour patients were excluded at surgery and are not involved in the follow-ups. At 1 year, 61 patients (244 implants) were evaluable and all bridges were in function. After 3 years, 49 patients (194 implants) came to control. Eight patients died during the follow-up period. Three patients lost one implant each. The cumulative implant survival rate was 98.55% and the success rate for the prosthesis was 100%. As calculated from measurable radiographs, the mean bone level at baseline was 1.63±0.78 and at 1 and 3 years 2.50±0.60 and 2.56±0.74, respectively. Using the mixed model analysis and Friedman test, the time in situ, centre and bone class had significant effect on the bone resorption and to some small extent even, the implant length. Gender and age were unaffected. Oral hygiene and patient satisfaction of the treatment were improved.The results indicate that one-part self-tapping sandblasted, large-grit, acid-etched (SLA) implants are suitable for loading within 1 week. In the whole period, the mean bone crestal resorption was1 mm, which is in agreement with other similar studies.

One of the principal goals in tissue engineering is to produce scaffold materials that will guide cells to differentiate and regenerate functional replacement tissue at the site of injury. Poly(l-lactide-co-1,5-dioxepan-2-one) [Poly(LLA-co-DXO)], a potential scaffolding material for bone tissue engineering, has high hydrophilicity. Previous in vitro studies using human osteoblast-like cells (HOBs) demonstrated greater cytocompatibility and enhanced osteogenic differentiation when HOBs were seeded onto Poly(LLA-co-DXO) compared to Poly(l-lactide) [P(LLA)] scaffolds. The aim of the study was to identify the gene expression profiles of HOBs obtained from alveolar bone and grown on Poly(LLA-co-DXO) biodegradable polymer scaffolds compared to P(LLA) one. Illumina HumanWG-6 v3.0 Expression BeadChips were used for the gene expression analysis. Several genes were found as differentially expressed at 24 h and at 21 days. Expression of genes related to cell adhesion, cytoskeleton, antiapoptosis, proliferation, and bone mineralization was influenced by adding the monomer 1,5-dioxepan-2-one to the L-lactide. Genes related to three biological pathways involving Integrin, Notch, and Ras were found to be upregulated. For selected genes, results were confirmed by quantitative reverse transcriptase-polymerase chain reaction. Further, calcium content analysis revealed a significant enhancement of calcium deposition on both tested scaffolds. This observation was confirmed by Von Kossa and Alizarin Red S staining. Findings of this study are relevant to a better understanding of the molecular mechanisms underlying the behavior of HOBs in bone regenerative procedure.

Degradation characteristics in response to electron beam sterilization of designed and biodegradable aliphatic polyester scaffolds are relevant for clinically successful synthetic graft tissue regeneration. Scaffold degradation in vitro and in vivo were documented and correlated to the macroscopic structure and chemical design of the original polymer. The materials tested were of inherently diverse hydrophobicity and crystallinity: poly(L-lactide) (poly(LLA)) and random copolymers from L-lactide and ε-caprolactone or 1,5-dioxepan-2-one, fabricated into porous and non-porous scaffolds. After sterilization, the samples underwent hydrolysis in vitro for up to a year. In vivo, scaffolds were surgically implanted into rat calvarial defects and retrieved for analysis after 28 and 91days. In vitro, poly(L-lactide-co-1,5-dioxepan-2-one) (poly(LLA-co-DXO)) samples degraded most rapidly during hydrolysis, due to the pronounced chain-shortening reaction caused by the sterilization. This was indicated by the rapid decrease in both mass and molecular weight of poly(LLA-co-DXO). Poly(L-lactide-co-ε-caprolactone) (poly(LLA-co-CL)) samples were also strongly affected by sterilization, but mass loss was more gradual; molecular weight decreased rapidly during hydrolysis. Least affected by sterilization were the poly(LLA) samples, which subsequently showed low mass loss rate and molecular weight decrease during hydrolysis. Mechanical stability varied greatly: poly(LLA-co-CL) withstood mechanical testing for up to 182 days, while poly(LLA) and poly(LLA-co-DXO) samples quickly became too brittle. Poly(LLA-co-DXO) samples unexpectedly degraded more rapidly in vitro than in vivo. After sterilization by electron beam irradiation, the three biodegradable polymers present widely diverse degradation profiles, both in vitro and in vivo. Each exhibits the potential to be tailored to meet diverse clinical tissue engineering requirements.

Constructs intended for bone tissue engineering are influenced by the initial cell seeding procedure. The seeding method should be rapid, convenient, improve cell spatial distribution, and have no negative effects on cellular viability and differentiation. This study aimed to compare the effect of short-run seeding methods (centrifuge and vortex) with a static method on the scaffolds prepared from poly(L-lactide-co-1,5-dioxepan-2-one) by solvent-casting particulate-leaching (SCPL) technique. Human osteoblast-like cells (HOB) were seeded by the three methods described above. The seeding efficiency was determined by attached cell numbers. Cellular proliferation was analyzed by WST-1 and dsDNA assay. Cell distribution was examined by scanning electron (SEM) and fluorescence microscopy. Expression of Alkaline Phosphatase (ALP), Collagen type I (Col I), Osteocalcin (OC) and Proliferating Cell Nuclear Antigen (PCNA) were determined by real time RT-PCR. Results indicated that centrifuge and vortex increased seeding efficiency and had no negative effects on cellular viability. The data obtained by the fluorescence microscope confirmed the SEM results that the vortex method improved cell distribution through the scaffolds more than the other two methods (p

In this in vitro study, the initial response of human periodontal ligament (PDL) cells and alveolar osteoblast-like cells (HOB) to three biodegradable polymers with varying pore size and different mechanical properties were evaluated. Scaffolds were synthesized from poly(L-lactide), [poly(LLA)], poly(L-lactide-co-1,5-dioxepan-2-one), [poly(LLA-co-DXO)], poly(L-lactide-co-ε-caprolactone), and [poly(LLA-co-CL)] with pore sizes greater or less than 90 µm by salt leaching. Cells were obtained from patients undergoing routine oral surgery. After 2—4 passages, the cells were grown on scaffolds and in culture plates (control) for 3 h (PDL cells), 3 days (PDL cells and HOB), 10 and 14 days (HOB), respectively. The cellular morphology and spreading were determined by scanning electron microscopy (SEM) and the attachment and proliferation were evaluated by MTT assays. The SEM images revealed heterogeneous cellular morphology and good spreading. Cellular attachment and proliferation were significantly higher on poly(LLA-co-DXO) and poly(LLA-co-CL) than on poly(LLA) scaffolds (p = 0.003) and highest for poly(LLA-co-DXO). Expression of bone formation markers, collagen-I (COL-I), transforming growth factor-β 1 (TGF-β1), and osteocalcin (OCN), was determined by ELISA. The expression of COL-1 was similar for HOB and PDL cells, but significantly higher for pore size >90 µm while the HOB expression of TGFβ 1 and OCN was greater on poly(LLA-co-CL) and poly(LLA-co-DXO) than on poly(LLA) scaffolds.

The aim of this study was to evaluate the in vitro cytotoxicity and cytocompatibility of the developed aliphatic polyester co-polymer scaffolds: poly(L-lactide-co-ε-caprolactone) and poly(L-lactide-co-1,5-dioxepan-2-one). The scaffolds were produced by solvent casting and particulate leaching, and tested by direct and indirect contact cytotoxicity assays on human osteoblast-like cells and mouse fibroblasts. Cell morphology was documented by light and scanning electron microscopy. Viability was assessed by the MTT, neutral red uptake, lactic dehydrogenase and apoptosis assays. Extraction tests confirmed that the scaffolds did not have a cytotoxic effect on the cells. The cells grew and spread well on the test scaffolds with good cellular attachment and viability. The scaffolds are noncytotoxic and biocompatible with the two cell types and warrant continued investigation as potential constructs for bone tissue engineering.

In this report, poly(L-lactide-co-ε-caprolactone), poly(LLA-co-CL) and poly(L-lactide-co-1,5-dioxepan-2-one), poly(LLA-co-DXO) were evaluated and compared for potential use in bone tissue engineering constructs together with bone marrow stromal cells (BMSC). The copolymers were tailored to reduce the level of harmful tin residuals in the scaffolding. BMSC isolated from Sprague—Dawley rats were seeded onto the scaffolds and cultured in vitro for up to 21 days. Cell spreading and proliferation was analyzed after 72 h by scanning electron microscopy and thiazolyl blue tetrazolium bromide (MTT) conversion assay. Osteogenic differentiation of BMSC was evaluated by real-time PCR after 14 and 21 days of culture. Hydrophilicity was significantly different between poly(LLA-co-CL) and poly(LLA-co-DXO) with the latter being more hydrophilic. After 72 h, both scaffolds supported increased cell proliferation and the mRNA expression of osteocalcin and osteopontin was significantly increased after 21 days. Further investigation of these constructs, with lower levels of tin residuals, are being pursued.

Objectives: This prospective multicentre study provides clinical experience up to 3 years to support a simplified treatment for mandibular edentulism within 1 week by using one-stage implant surgery and a screw-retained full-arch bridge. Methods: Two hundred and fifty ITI Monotype® implants were installed in 62 patients out of 66 patients; 60 patients got four implants each and two got five implants. After 1 week, a final bridge was in function. Radiographs were taken as baseline for vertical bone loss up to 3 years post-loading for the whole cluster and specific effects of gender, centre, age, bone class, implant length over time were compiled. Clinical (mPI, SBI) and subjective parameters such as general oral hygiene and patient satisfaction were recorded and repeated at specified intervals up to 3 years. Results: Four patients were excluded at surgery and are not involved in the follow-ups. At 1 year, 61 patients (244 implants) were evaluable and all bridges were in function. After 3 years, 49 patients (194 implants) came to control. Eight patients died during the follow-up period. Three patients lost one implant each. The cumulative implant survival rate was 98.55% and the success rate for the prosthesis was 100%. As calculated from measurable radiographs, the mean bone level at baseline was 1.63±0.78 and at 1 and 3 years 2.50±0.60 and 2.56±0.74, respectively. Using the mixed model analysis and Friedman test, the time in situ, centre and bone class had significant effect on the bone resorption and to some small extent even, the implant length. Gender and age were unaffected. Oral hygiene and patient satisfaction of the treatment were improved. Conclusions: The results indicate that one-part self-tapping sandblasted, large-grit, acid-etched (SLA) implants are suitable for loading within 1 week. In the whole period, the mean bone crestal resorption was

The 19 patients included in this study had all been successfully treated for total or partial edentulism with single crystal sapphire implants as retention for overdentures or fixed bridges. As there is a need for more reliable non-invasive parameters for detecting changes surrounding endosseous implants, the aim of this study was to assess the content and the activity of neutrophils in crevicular fluid samples from 3 categories of sites: (1) crevices around implants from edentulous patients (2) crevices around implants in partially edentulous patients, and (3) crevices surrounding teeth. Fluid samples were taken with paper strips from 9 partially edentulous and 10 edentulous patients and the volume measured with a Periotron 6000@. Elastase activity was measured as a marker of neutrophil activity and lactoferrin concentration as a marker of the number of neutrophils. Elastase activity per pl and lactoferrin concentration was, despite similar clinical and radiographic signs, significantly higher in samples from crevices surrounding teeth and implants in the partially edentulous patients compared to samples from crevices around implants in the totally edentulous patients. There were no differences between teeth and implants in partially edentulous patients. The increased elastase activity and lactofemn concentration indicates a higher neutrophil activity in patients with remaining teeth. Resume Les dix-neuf patients faisant partie de cette etude ont tous ete traites avec succes pour une edentation partielle ou totale avec des implants unitaires en saphir en tant que piliers de protheses aniovibles ou inamovibles. Comme il est necessaire d'avoir des parametres sfirs et non-invasifs pour detecter les variations entourant les implants le but de cette etude a ete d'analyser le contenu et l'activite des neutrophiles dans le fluide creviculaire de trois categories de sites: (1) de sillons autour des implants de patients edentes, (2) de sillons autour d'implants de patients edentes partiellement et (3) de sillons autour de dents. Des echantillons croviculaires ont ete pris avec des bandelettes de papier de neuf edentes partiels et de dix edentes, et le volume mesure avec le Periotron 6000. L'activite de l'Clastase a ete mesuree comme marqueur de l'activite neutrophile et la concentration en lactoferrine comme marqueur du nombre de neutrophiles. L'activite de l'elastase par μl et la concentration en lactofkrrine Ctaient, malgrk des signes cliniques et radiogra-phiques semblables, significativenient, plus importantes dans les echantillons provenant de sillons autour de dents et d'implants chez les edentes partiels qu'autour d'implants chez les patients edentes. Il n'y avait aucune difference entre dent et implant chez les patients partiellement edentes. L'augmentation de I'activite de I'elastase et la concentration en lactoferrine indiquent une activite des neutrophiles plus importantes chez les patients ayant dentes. Zusammenfassung Alle 19 Patienten, welche in die Untersuchung einbezogen wurden, waren zuvor erfolgreich mit Hybridprothesen oder festsitzenden Brucken auf Einzelkristallsapphireimplantaten versorgt worden. Da ein Bedurfnis nach mehr nichtinvasiven verlasslichen Parametern zur Aufdeckung von Veranderungen um enossale implantate besteht, bestand das Ziel dieser Untersuchung darin, den Gehalt und die Aktivitat von neutrophilen Granulozyten in SulcusfuUssigkeitsproben von 3 verschiedenen Kategorien von Stellen zu messen. 1) Sulci um implantate bei zahnlosen Patienten 2) Sulci um implantate bei teilbezahnten Patienten und 3) Sulci um Zahne. Die Flussigkeitsproben wurden mittels Papirstreifen bei 9 teilbezahnten und bei 10 zahnlosen Patienten entnommen und das Volumen wurde mit dem Periotron 6000 gemessen. Als Marker fur die Aktivitat der neutrophilen wurde die Elastaseaktivitat bestimmt und die Lactoferrinkonzentration diente als Marker fur die Anzahl an neutrophilen. Die Elastaseaktivitat per μl und die Lactoferrinkonzentration waren, obwohl klinisch und radiologisch keine Unterschiede bestanden, signifikant hoher in den Proben aus den Sulci von Zahnen und Implantaten bei teilbezahnten Patienten im Vergleich zu Proben aus Sulci von Implantaten bei zahnlosen Patienten. Zwischen Zahnen und Implantaten bei teilbezahnten Patienten bestanden keine Unterschiede. Die er-hohte Elastaseaktivitat und Lactoferrinkonzentration bedeutet eine grossere Aktivitat der Neutrophilen bei Patienten mit verbleibenden Zahnen. Resumen Los 19 pacientes encluidos en este estudio habian sido tratados con exito a causa de edentulismo total o parcial con implantes unitarios de zafiro como retencion para sobredebtaduras o puentes fijos. Al existir una necesidad de parametros no invasivos mas fiables para detectar cambios alrededor de implantes endooseos, la intencion de este estudio fue de la valorar el contenido y actividad de los neutrofilos en las muestras de liquido crevicular de tres categorias de sitios: (1) Crevices alrededor de implantes de pacientes edentulos (2) crevices alrededor de implantes en pacientes parcialmente edentulos y (3) crevises alrededor de dientes. Se tomaron muestras de fluido con tiras de papei de nueve pacientes parcialmente edentulos y diez pacientes edentulos y el volumen sa midio con un Periotron 6000. Se midio la actividad de la elastasa como un marcador de la actividad neutrofilia y la concentracion de lactoferrina, como un marcador del numero de neutrofilos. La actividad de la elastasa por μl y la concentracion de lactofemna fue, a pesar de los signos clinicos y radiogagficos similares, significativamente mas aka en las muestras de la crevices alrededor de los dientes y de los implantes en pacientes parcialmente edentulos en comparacion con muestras de los crevices alrededor de los implantes en los pacientes totalmente edentulos. No hubo diferencias entre dientes e implantes en los pacientes parcialmente edentulos. La actividad aumentada de la elastasa y de la concentracion de la lactoferrina indican una mayor actividad de los neutrofilos en los pacientes con dientes remanentes.

The surface roughness of an implant to which osteoblasts attach may influence endogenous expression of growth factor and cytokines at the implant–tissue interface, modulating the healing process and affecting the quality of bone formation. The present study, using cells derived from human mandibular bone, investigated the effect of varying roughness of titanium surfaces on production of transforming growth factor β1 (TGF-β1) and prostaglandin E2 (PGE2). The titanium surfaces were turned (control) and then roughened by blasting with 63–90 µm, 106–180 µm or 180–300 µm TiO2 particles. The cells were cultured onto the surfaces till confluence was achieved. Fresh media were added in the presence or absence of 1,25-dihydroxyvitamin D3[1,25-(OH)2D3], the stimulator of osteogenic differentiation, and aliquots of conditioned cell media were used for assay 24 h later. Cellular morphology was determined by scanning electron microscopy. Cellular production of TGF-β1 and PGE2 on each surface was assessed by enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay (RIA), respectively, using commercially available kits. All blasted surfaces showed significantly higher production of TGF-β1 than the turned surfaces (P

In the complex process of bone formation at the implant-tissue interface, implant surface roughness is an important factor modulating osteoblastic function. In this study, primary cultures of osteoblast-like cells, derived from human mandibular bone, were used. The aim was to examine the effect of varying surface roughness of titanium implant material on cellular attachment, proliferation and differentiation. A recognized method of increasing surface roughness and enlarging the surface area of titanium implants is by blasting with titanium dioxide particles: the four specimen types in the study comprised surfaces which were machine-turned only, or blasted after turning, with 63-90 microm, 106-180 microm, or 180-300 microm TiO(2) particles, respectively. The specimens were analyzed by scanning electron microscopy and confocal laser scanning. The turned samples had the smoothest surfaces: average height deviation (S(a)) of 0.20 microm. The roughest were those blasted with 180-300 microm particles, S(a) value 1.38 microm. Blasting with intermediate particle sizes yielded S(a) values of 0.72 microm and 1.30 microm, respectively. Cell profile areas were measured using a semiautomatic interactive image analyzer. Figures were expressed as percentage of attachment. DNA synthesis was estimated by measuring the amount of [(3)H]-thymidine incorporation into trichloroacetic acid (TCA) insoluble cell precipitates. The specific activity of alkaline phosphatase was assayed using p-nitrophenylphosphate as a substrate. The ability of the cells to synthesize osteocalcin was investigated in serum-free culture medium using the ELSA-OST-NAT immunoradiometric kit. After 3 h of culture, the percentage of cellular attachment did not differ significantly between specimens blasted with 180-300 micromparticles and the turned specimens. All blasted surfaces showed significantly higher [(3)H]-thymidine incorporation than the turned surfaces (P

This study was performed to determine the effect of commercially pure titanium surfaces blasted with TiO2 particles on the biological responses of cells derived from human mandibular bone. The morphology and attachment of those cells were investigated on turned titanium surfaces (control) and surfaces blasted with 45 μm (standard), 45–63 μm, and 63–90 μm TiO2 particles. The surfaces were analyzed in a scanning electron microscope. Based on surface analyses reported elsewhere, the turned samples had the smoothest surfaces and the roughest were those blasted with the largest particles (63–90 μm). The cell profile areas were measured using a semi-automatic interactive image analyzer. The attachment was determined as a ratio of the area of cell profiles and the total micrograph area and was expressed as percentage of attachment. Morphologically, the cells were heterogeneous. In general, the cells had spread well on all titanium surfaces, indicating good attachment to both smooth and rough surfaces. After 1, 3 and 6 h, the percentage of cell attachment did not differ significantly between the surfaces blasted with 63–90 μm and the turned surfaces, but was significantly lower on the surfaces blasted with 45 μm or 45–63 μm particles. After 24 h the surfaces blasted with 63–90 μm particles had a higher rate of cell attachment than all the other surfaces including the controls. It is concluded that attachment and growth of cells originating from human mandibular bone in vitro, are influenced by the micro-texture of the implant surface.

ObjectiveTo study the number of taste buds and, with the use of specific markers for peripheral nervous tissue, to study the neuronal pattern in taste buds from 36 patients with chronic renal failure (CRF), 19 renal transplant recipients, and 40 healthy subjects. Of the patients with CRF, 17 patients had not started dialysis, 12 patients were on peritoneal dialysis, and 7 patients were on hemodialysis.DesignFrom all subjects, two or three fungiform papillae were collected from the anterior part of the tongue. Cryostat sections were cut and inspected under light microscopy to determine the presence of taste buds. The sections were subsequently incubated with primary rabbit antibodies against protein gene product 9.5, substance P, and nerve growth factor receptor.ResultsUsing these antibodies, no differences between the groups were observed. However, patients with CRF had fewer taste buds than control subjects.ConclusionNo immunohistochemical differences were observed between patients with CRF and healthy controls. However, patients with CRF had significantly fewer fungiform taste buds, suggesting an important factor contributing to the well-known impairment of taste acuity in this patient group.

The toxicity of formaldehyde, a monomer released from certain polymeric dental materials, was studied in cultured human oral fibroblasts and epithelial cells. The influences of growth conditions were evaluated for both cell types, as well as the role of the internal and external thiol states. A one-hour exposure to formaldehyde decreased the colony-forming efficiency (CFE) of both cell types in a concentration-dependent manner, although the toxicity varied up to 100-fold with the conditions. Clearly, the presence of serum and the thiol cysteine counteracted the toxicity in fibroblasts. Similarly, pituitary extract and cysteine, or a mixture of amino acids and ethanolamines, counteracted the formaldehyde toxicity in serum-free cultures of epithelial cells. In contrast, a growth-promoting surface matrix of fibronectin and collagen did not influence the formaldehyde toxicity, as shown by both the CFE assay and a dye reduction assay. Further, a short-term change to the various growth media per se with or without the supplements serum or cysteine did not significantly alter the CFE. Analysis of the thiol state demonstrated significant differences between epithelial cells and fibroblasts, i.e., comparatively lower cellular levels of the free low-molecular-weight thiols glutathione and cysteine in fibroblasts. This result correlated to significantly higher formaldehyde toxicity in the fibroblasts than in the epithelial cells. Taken together, the results indicated the cytoprotective function of both intracellular and extracellular thiols toward formaldehyde, as well as the usefulness of thiol-free and chemically defined conditions for toxicity assessments in oral epithelial cells and fibroblasts. We conclude that the combined use of a controlled external milieu and the presumed target cell type may be advantageous in evaluations of oral toxicity mechanisms or the toxic potency of dental materials, particularly those which, like formaldehyde, may react with thiols or amines.

This report of the 1st 2 prospective studies using the Astra Tech Implant System and fixed detachable bridges for rehabilitation of mandibular edentulism, presents clinical and radiographic data at the 5-year follow-up. The original material comprised 109 subjects, 56 of whom had been included in the original study, using the 1st generation Astra Tech Implant. Two subjects were excluded and the 3-year follow-up report was based on the remaining 54 subjects and 310 fixtures. After some minor changes to the fixture and the abutment, the 2nd generation Astra Tech Implant was used in 53 subjects and 308 fixtures. In all 16 subjects were lost to follow-up and the 5-year results are based on the remaining 91 subjects with 517 fixtures in function: 5 fixtures were lost due to mobility at abutment installation and during the 1st year, 2 fixtures were removed due to pain, and after 4 years in situ 1 fixture failed. As no clinical or radiographic differences were obvious in the annual registrations of the 2 studies the results have been combined. The fixed bridges were removed at 3 and 5 years to test each fixture and none was mobile. The cumulative fixture survival rate at 5 years was 98.7% and the bridge survival rate was 100%. Of the sites 82% were plaque free, and 96.8% showed no signs of inflammation. Over the 5-year period after bridge insertion, i.e. from baseline registration, there was only minor deterioration in marginal bone levels as measured on standardized intraoral radiographs: the mean differences in mm and standard deviations (SD) were -0.09 (0.27) in the 1st year, -0.20 (0.40) in the 3rd year, and -0.26 (0.53) in the 5th year. According to the stringent clinical and radiographic criteria by Albrektsson and co-workers, the successful treatment outcome and the survival rate in 91 subject over 5 years, indicates that the Astra Tech Dental Implant System with fixed detachable bridges is an appropriate method for rehabilitation of mandibular edentulism.

The purpose of this study was to determine the effect of c.p. titanium surfaces blasted with TiO2 particles on the biological responses of human gingival fibroblasts (HGF). Fibroblast morphology and attachment were investigated on turned (control) titanium surfaces and those blasted with 45 μm (standard), 45Ndash;63 μm, and 63–90 μm TiO2 particles. The specimens were analyzed using a confocal laser scanner and SEM. The cell profile areas were measured using a semiautomatic interactive image analyser. The figures were expressed as percent of attachment. The turned samples had the smoothest surfaces and the roughest were those blasted with 63–90 μm. All TiO2 blasted specimens had homogeneous surfaces. Cells appeared to flatten, spread and form cellular bridges with the adjacent cells. Fibroblasts on the turned titanium surfaces appeared to follow the direction of the fine irregularities on the surface but tended to spread haphazardly on the blasted surfaces. The attachment assays showed no significant difference in the percentage of fibroblast cell attachment on the standard surfaces compared to the turned surfaces. Both surfaces blasted with 45–63 μm or 63–90 μm had significantly (P

The occurrence and distribution of several neurochemical markers were investigated. Numerous nerve fibres were shown, using antibodies to protein gene product (PGP) 9.5, neurone-specific enolase, calcitonin gene-related peptide (CGRP), substance P, neurokinin A or protein S-100. The presence of vasoactive intestinal polypeptide (VIP), peptide histidine isoleucine amide (PHI), neuropeptide tyrosine, dopamine-β-hydroxylase (DBH), cholecystokinin/gastrin, glutamate and galanin was more scarce. Nerve fibres containing these above-mentioned markers were found at several locations, i.e. in the epithelium, connective tissue, and around blood vessels. In the taste buds, numerous PGP 9.5-, neurone-specific enolase-, CGRP-, substance P-, neurokinin A- and protein S-100-containing structures were found, but few VIP and galanin ones. No immunoreactivity was found with antibodies against somatostatin, bombesin, enkephalin or dynorphin. These findings extend knowledge about the general as well as the neurochemical messenger-based innervation of rat fungiform papillae, forming a firm basis for future functional investigations of normal, experimental and also clinical materials.

Regenerative medicine and dentistry are two rapidly growing fields of research with important clinical implications. Recent advances in cell biology, biotechnology, material science and tissue transplantation have been translated into new approaches to clinical repair and replacement of tissues and organs. In dentistry, a number of regenerative therapies and materials have been in clinical use for many years, to repair small and large defects involving multiple tissue types. Currently, various strategies are applied to stimulate healing of bone defects and to restore lost maxillofacial bone and periodontal support following traumatic insult, tumor ablation, disease or congenital deformities.

86 patients, in 2 Scandinavian centers, participated in a prospective study of mandibular edentulism, treated with overdentures supported by Bioceram sapphire implants. Implant success and prosthesis stability as well as parameters for peri-implant health were evaluated. Masticatory function and complications were also documented. The study began in 1982 and clinical treatment of the last patients was completed in 1991. The patients have been followed for at least 3 years, and up to 12 years. 4 patients were lost to follow-up. Of the initial 324 implants, 7 implants failed before prosthetic treatment. 3 patients lost 1 implant each within the 1st year, and 4 patients lost all 4 implants. 16 implants were lost between 36 and 42 months in function, due to lack of osseointegration and pain. The loss of implants could be attributable to an association, not statistically verified, between bone quality and anatomy, with heavy smoking as a risk factor. Based on the remaining implants, the cumulative implant success rates were 95.2%, 91.3%, 91.3%, 91.3% at 3, 5, 10 and 12 year follow-up, respectively. The cumulative success rates for overdentures were 96.4%, 92.8%, 92.8% and 92.8% respectively, for the same follow-up periods. Indices for the health of the peri-implant mucosa disclosed no serious inflammatory reactions in the surrounding soft tissues. Patient satisfaction with this form of oral rehabilitation was high in all but 2 patients who experienced discomfort.

Soft tissues surrounding Branemark titanium implants and single crystal sapphire implants were studied by conventional light- and transmission electron microscopy and by immunohistochemical markers for cytokeratin, protein S-100, Factor VIII and KP1. Histological sections of biopsies obtained from clinically healthy peri-implant mucosa were separated into a keratinized outer implant epithelium and an inner, non-keratinized epithelium, both immunoreactive towards cytokeratin. The inner implant epithelium terminated in a junctional epithelium, apically only a few cell layers thiih. The cells adjacent to the implant showed a condensed cytoplasm, resembling hemidesmosomes. In the underlying connective tissue, rich in fibroblasts and factor VIII immunoreactive blood vessels, the bundles of collagen ran in different directions. S-100 immunoreactive nerve structures were more frequently found beneath the outer than the inner implant epithelium. Inflammatory cell infiltrates, some KP1 positive, were observed in the apical parts of the inner implant epithelium. S-100 positive Langerhans' cells were present mainly within the the outer implant epithelium. For the two implant systems, the techniques disclosed no qualitative structural differences in the adjacent soft tissues.

Our recent in vitro study demonstrated that endothelial cells (ECs) might influence the differentiation of bone marrow stromal cells (BMSCs). Therefore, the aim of this study was to describe this effect in vivo, using a rat calvarial bone defect model. BMSCs were isolated from femurs of two-donor Lewis rats and expanded in α-minimum essential medium containing 10% fetal bovine serum. One fifth of BMSCs were induced and differentiated into ECs in an Endothelial Cell Growth Medium-2 and then characterized by a flow cytometry. The remaining BMSCs were cultured in freshly prepared osteogenic stimulatory medium, containing dexamethasone, ascorbic acid and β-glycerophosphate. Either BMSCs alone (BMSC-group) or co-cultured ECs/BMSCs (CO-group) were seeded into poly(L-lactide-co-1,5-dioxepan-2-one) [poly(LLA-co-DXO)] scaffolds, cultured in spinner flasks, and then implanted into symmetrical calvarial defects prepared in recipient rats. The animals were sacrificed after 2 months. The formation of new bone was evaluated by radiography and histology and by the expression of osteogenic markers using reverse transcriptase-polymerized chain reaction (RT-PCR). To investigate vessel formation, histological staining was performed with EC's markers. The radiographical and histological results showed more rapid bone formation in the CO- than in the BMSC-group. However, the expression of EC's marker was similar on both groups by histological analysis after 2 months postoperatively. Furthermore, the CO-group exhibited greater expression of osteogenic markers as demonstrated by RT-PCR. The results are consistent with the previous in vitro findings that poly(LLA-co-DXO) scaffold might be suitable candidate for bone tissue engineering. In vivo, bone regeneration was enhanced by a construct of the polymer scaffold loaded with co-cultured cells.

In tissue engineering, the resorbable aliphatic polyester poly(L-lactide) (PLLA) is used as scaffolds in bone regeneration. Copolymers of poly(L-lactide)-co-(e-caprolactone) [poly(LLA-co-CL)] and poly(L-lactide)-co-(1,5-dioxepan-2-one) [poly(LLA-co-DXO)], with superior mechanical properties to PLLA, have been developed to be used as scaffolds, but the influence on the osteogenic potential is unclear. This in vitro study of test scaffolds of poly(LLA-co-CL) and poly(LLA-co-DXO) using PLLA scaffolds as a control demonstrates the attachment and proliferation of human osteoblast-like cells (HOB) as measured by SEM and a methylthiazol tetrazolium (MTT) colorimetric assay, and the progression of HOB osteogenesis for up to 3 weeks; expressed as synthesis of the osteoblast differentiation markers: collagen type 1 (Col 1), alkaline phosphatase, bone sialoprotein, osteocalcin (OC), osteopontin and runt related gene 2 (Runx2). Surface analysis disclosed excellent surface attachment, spread and penetration of the cells into the pores of the test scaffolds compared to the PLLA. MTT results indicated that test scaffolds enhanced the proliferation of HOBs. Cells grown on the test scaffolds demonstrated higher synthesis of Col 1 and OC and also increased bone markers mRNA expression. Compared to scaffolds of PLLA, the poly(LLA-co-CL) and poly(LLA-co-DXO) scaffolds enhanced attachment, proliferation, and expression of osteogenic markers by HOBs in vitro. Therefore, these scaffolds might be appropriate carriers for bone engineering. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010

A fundamental component of bone tissue engineering is an appropriate scaffold as a carrier for osteogenic cells. The aim of the study was to evaluate the response of human bone marrow stromal cells (BMSC) to scaffolds made of three biodegradable polymers: poly(L-lactide-co-e-caprolactone) (poly(LLA-co-CL)), poly(L-lactide-co-1,5dioxepan-2-one) (poly(LLA-co-DXO)), and poly(L-lactide) (poly(LLA)). Cellular response was evaluated in terms of attachment, proliferation, and differentiation. SEM disclosed earlier cell attachment and better spreading on poly(LLA-co-CL) and poly(LLA-co-DXO) scaffolds than on poly(LLA) after 1 h. At 24 h and 14 days postseeding, BMSCs had spread well, forming multiple cellular layers on the scaffolds. Cell proliferation was higher on poly(LLA-co-CL) and on poly(LLA-co-DXO) than on poly(LLA) after 1 and 7 days. Cell growth cycles of BMSC were longer on the scaffolds than on coverslips. After 7 and 14 days cultivation on scaffolds, the expression of osteogenic markers such as ALP, Col I, OPN, and Runx2 were stimulated by BMSC, which indicating that poly(LLA-co-DXO), poly(LLA-co-CL), and poly(LLA) could support the osteogenic differentiation of BMSC in vitro. Poly(LLA-co-CL) and poly(LLA-co-DXO) promoted better attachment and growth of BMSC than poly(LLA). BMSC also retained their osteogenic differentiation potential, indicating biological activity of BMSC on the scaffolds. The promising results of this in vitro study indicate that these copolymers warrant further evaluation for potential application in bone tissue engineering.

Taste detection and recognition thresholds were monitored in 10 patients for up to 1 yr after allogeneic bone marrow transplantation (BMT). As well as a control group of 12 healthy volunteers, taste acuity was tested in 10 patients, who had undergone BMT 2–5 yr previously. Immediately after transplantation, there was significant hypogeusia of all four taste modalities compared to registrations one week before the a plastic phase and also compared to the healthy control group. Although some normalization of taste thresholds was registered 3–6 months after transplantation, most subjects still experienced dysgeusia. Of the four taste modalities, the most frequently recorded change was a raised threshold for salt. In about 80% of the patients taste acuity had recovered to the control values one year after transplantation. The group tested 2–5 yr after BMT had normal values for taste acuity.

Background Improved understanding of the interactions between bone cells and endothelial cells involved in osteogenesis should aid the development of new strategies for bone tissue engineering. The aim of the present study was to determine whether direct communication between bone marrow stromal cells (MSC) and human umbilical vein endothelial cells (EC) could influence the osteogenic potential of MSC in osteogenic factor-free medium. Methods After adding EC to MSC in a direct-contact system, cell viability and morphology were investigated with the WST assay and immnostaining. The effects on osteogenic differentiation of adding EC to MSC was systematically tested by the using Superarray assay and results were confirmed with real-time PCR. Results Five days after the addition of EC to MSC in a ratio of 1:5 (EC/MSC) significant increases in cell proliferation and cellular bridges between the two cell types were detected, as well as increased mRNA expression of alkaline phosphatase (ALP). This effect was greater than that seen with addition of osteogenic factors such as dexamethasone, ascorbic acid and β-glycerophosphate to the culture medium. The expression of transcription factor Runx2 was enhanced in MSC incubated with osteogenic stimulatory medium, but was not influenced by induction with EC. The expression of Collagen type I was not influenced by EC but the cells grown in the osteogenic factor-free medium exhibited higher expression than those cultured with osteogenic stimulatory medium. Conclusion These results show that co-culturing of EC and MSC for 5 days influences osteogenic differentiation of MSC, an effect that might be independent of Runx2, and enhances the production of ALP by MSC.

Human buccal epithelial cells have been reared from explants maintained in supplemented MCDB 153 medium. Primary epithelial outgrowths show typical structural features and uniformly express keratins; subunit analyses demonstrate expression of keratins 5, 6, 14, 16/17, and 19. The cells exhibit up to 6% colony forming efficiency and divide at about 0.8 population doublings per day on fibronectin/collagen-coated dishes at clonal density. Studies of markers of proliferation and differentiation in buccal epithelial cells indicate that epidermal growth factor, cholera toxin, retinoic acid, and pituitary extract each exhibit a distinctive ability to enhance growth and variably affect cell migration and cell surface area. Transforming growth factor beta-1 inhibits growth and increases surface area without affecting migration, involucrin expression, and cross-linked envelope formation. Moreover, exposure of cells to fetal bovine serum, the tumor promoting agent 12-O-tetradecanoylphorbol-13-acetate or an elevated Ca2+ concentration (from 0.1 to 1 mM) inhibits growth and induces squamous differentiation as indicated by inhibition of migration, increases in surface area, involucrin expression, or formation of cross-linked envelopes. The results show that epithelial cells can be reproducibly derived from explant cultures of human buccal mucosa specimens and the cells transferred under serum-free conditions. Buccal epithelial cells in culture undergo a pattern of growth and differentiation that mimics parakeratinization in vivo and variably respond to several agents shown to modulate growth of cells that originate from other types of epithelia.

Successful attachment of the oral tissues to an endosseous dental implant relies in part on its chemical stability, nontoxic properties and maintenance of normal cell functions in the surrounding tissues. The aim of this study was therefore to investigate these 3 factors experimentally. The corrosion resistance of single crystal sapphire (alpha-Al2O3) implants was analysed with respect to the release of aluminium ions; no ions could be detected in the test solutions. The influence of single crystal sapphire on the behaviour of human epithelial cells and fibroblasts derived from biopsies of the oral mucosa, was studied. The cells were cultured in chemically defined or in low serum-containing media. Compared to the corresponding control cultures, no effects on cell morphology and growth characteristics were observed. Sapphire rods were inserted subcutaneously into rats and tissue responses were examined after 4, 8 and 12 weeks post-implantation. None or slight reactions were found in the tissues. The combined evaluation of these experimental approaches indicates that single crystal sapphire is a material well suited for biological implantation.

Objectives: This in vitro study was aimed to investigate the attachment, spreading and proliferation of human gingival fibroblasts to milled and polished non-veneered ceramic surfaces in alumina and zirconia and to ceramic surfaces veneered by two different types of porcelain baseliners. Materials and methods: Fibroblasts were cultured on discs of pressed alumina or zirconia, on discs which had been milled, on discs comprising alumina or zirconia which had been polished, on discs of alumina veneered with NobelRondo baseliner Al, on discs of zirconia veneered with Cercon-S baseliner, and on alumina or zirconia discs veneered with the above baseliners and then polished. The surfaces were analyzed using an optical interferometer and scanning electron microscopy (SEM). Cell profile areas were measured using SEM and an image analyzer. Cell attachment was determined after 3 and 24 h as a ratio of the cell profiles and the total micrograph area and was expressed as percent of attachment. MTT analyses were undertaken to determine cellular attachment after 3 h of incubation and cellular proliferation after 7 days. Results: The polished zirconia specimens had the smoothest surface in terms of average height deviation (Sa=0.03 μm): the roughest were the zirconia specimens with milled surfaces (Sa=0.36 μm). The application of the baseliners resulted in surfaces smoother than those of the non-veneered discs. The milled surfaces of both alumina and zirconia had significantly higher percentages of cell attachment and proliferation than the other surfaces whereas the milled surfaces in zirconia demonstrated better cellular attachment after 3 and 24 h of culture than the one in alumina. Fibroblasts attached and grew effectively on the surfaces veneered with NobelRondo throughout the experiments, whereas the zirconia surfaces veneered with Cercon-S had the lowest percentage of cell attachment and proliferation. Conclusions: Although the roughness of all surfaces investigated was

This prospective multicentre study provides clinical experience up to 3 years to support a simplified treatment for mandibular edentulism within 1 week by using one-stage implant surgery and a screw-retained full-arch bridge.Two hundred and fifty ITI Monotype implants were installed in 62 patients out of 66 patients; 60 patients got four implants each and two got five implants. After 1 week, a final bridge was in function. Radiographs were taken as baseline for vertical bone loss up to 3 years post-loading for the whole cluster and specific effects of gender, centre, age, bone class, implant length over time were compiled. Clinical (mPI, SBI) and subjective parameters such as general oral hygiene and patient satisfaction were recorded and repeated at specified intervals up to 3 years.Four patients were excluded at surgery and are not involved in the follow-ups. At 1 year, 61 patients (244 implants) were evaluable and all bridges were in function. After 3 years, 49 patients (194 implants) came to control. Eight patients died during the follow-up period. Three patients lost one implant each. The cumulative implant survival rate was 98.55% and the success rate for the prosthesis was 100%. As calculated from measurable radiographs, the mean bone level at baseline was 1.63+/-0.78 and at 1 and 3 years 2.50+/-0.60 and 2.56+/-0.74, respectively. Using the mixed model analysis and Friedman test, the time in situ, centre and bone class had significant effect on the bone resorption and to some small extent even, the implant length. Gender and age were unaffected. Oral hygiene and patient satisfaction of the treatment were improved.The results indicate that one-part self-tapping sandblasted, large-grit, acid-etched (SLA) implants are suitable for loading within 1 week. In the whole period, the mean bone crestal resorption was1 mm, which is in agreement with other similar studies.

9 single crystal sapphire dental implants were installed bilaterally into pre-extracted areas in the lower jaw of two beagle dogs and histologically analysed after 180 days in situ. 8 implants were stable and radiographs disclosed complete bone healing. Light-, scanning- and transmission electron microscopy demonstrated that the stable implants were surrounded by a mineralizing bone boundary and a mutosa nearly free from inflammatory cell infiltrations. The 9th implant was mobile and surrounded by a non-mineralized connective tissue capsule containing bundles of collagen. The ultrastructure of the mucosa surrounding the implants closely resembled the mucosa surrounding the tooth. Histometric analysis of the alveolar bone surrounding the stable implants revealed that the value of the bone contact surface ranged from 37.1%% to 86.9% (mean value 61.8%) at the light microscopic level.

Optical tweezers were used to study the interaction and attachment of human bone cells to various types of medical implant materials. Ideally, the implant should facilitate cell attachment and promote migration of the progenitor cells in order to decrease the healing time. It is therefore of interest, in a controlled manner, to be able to monitor the cell adhesion process. Results from such studies would help foresee the clinical outcome of integrating medical implants. The interactions between two primary cell culture models, human gingival fibroblasts and bone forming human osteoblast cells, and three different implant materials, glass, titanium, and hydroxyapatite, were studied. A novel type of optical tweezers, which has a newly designed quadrant detector and a powerful 3 W laser was constructed and force calibrated using two different methods: one method in which the stiffness of the optical trap was obtained by monitoring the phase lag between the trap and the moved object when imposing a forced oscillation on the trapped object and another method in which the maximum trapping force was derived from the critical velocity at which the object escapes the trap. Polystyrene beads as well as cells were utilized for the calibrations. This is the first time that cells have been used directly for these types of force calibrations and, hence, direct measurements of forces exerted on cells can be performed, thus avoiding the difficulties often encountered when translating the results obtained from cell measurements to the calibrations obtained with reference materials. This more straightforward approach represents an advantage in comparison to established methods.

This study performed a clinical evaluation of two ceramic systems retained with resin-bonded cement, observed clinical outcomes over time, and compared the two systems used (IPS Empress and Vitadur Alpha) and differences between inlays and onlays.Three general practitioners placed 317 restorations (215 IPS Empress and 102 Vitadur Alpha) in 153 patients. The first clinical registration was performed 6 to 36 months after placement of the restorations by calibrated investigators using the CDA criteria. A second follow-up was performed 36 months later. The mean time in function for all restorations at follow-up was 60 months.At the first examination, five restorations were not clinically acceptable because of fractures and caries. At follow-up, another 16 restorations were judged as failures. The most significant changes over time were an increase in rough surfaces, evidence of increasing marginal discrepancy, and slight mismatch in color between restored tooth and ceramic restoration. When comparing IPS Empress to Vitadur Alpha, there was no difference in clinical performance. When comparing inlay and onlay restorations, there was a tendency toward a higher number of failures in the inlay group. The overall success rate was 92%.Ceramic restorations performed well after 5 years in function and provide a good treatment alternative that can be successfully managed in general dental practice.

The purpose of this study was to examine retrospectively the outcome of wide-diameter dental implants used to retain fixed restorations in the posterior segments of the maxilla and mandible.Fifty-two patients were consecutively treated between 1997 and 2000 with 78 Wide-Platform (WP) Mk II implants in the posterior regions of the maxilla and/or mandible. All treated patients were called for a retrospective examination between September and November 2001. At the examination, data regarding general health and clinical and radiographic parameters were collected according to a strict protocol. Thirty-four women and 18 men with a mean age of 55 years (range 19 to 81 years) participated. Twenty-three WP implants were placed in the maxilla and 55 in the mandible. The mean time in situ was 33 months (range of 11 to 58 months).Of 78 implants, 8 had been lost by the time of reexamination. Five women lost 1 implant each in the maxilla, and 2 men lost 3 implants in the mandible. The survival rate was 89.8%.The results are encouraging because the WP implants were placed in rather unfavorable situations (generally poor bone quality, compromised bone volume, and larger occlusal forces).Based on the reported survival rate, wide-diameter implants present an acceptable treatment alternative.

The aim of this retrospective longitudinal study was to document the outcomes of resin-cemented ceramic inlays in patients treated in a private dental practice over up to 9 years.Fifty-two patients received in all 109 Mirage ceramic inlays, 59 in molars and 50 in premolars. Follow-up data were collected on 51 patients and 107 inlays. The mean time in situ was 6.3 years. Technical failures or dislodgments of the inlays were recorded, as well as clinical and radiographic signs of periodontal and periapical diseases or caries lesions.During the follow-up period, 17 inlays had to be removed, 14 because of major fractures and 3 in teeth requiring endodontic treatment. The fractures were confined to 8 of the 51 patients available for follow-up and were significantly more common in molars than in premolars. Replacement of inlays was significantly more frequent in men than in women. During the study period, 20 further minor clinical interventions (eg, recementation of intact inlays, repair of minor fractures or caries defects) had been undertaken on the surviving inlays. Thus, major and minor complications together necessitated a total of 37 clinical interventions. The survival rate, based on the remaining 90 inlays still in situ, was 84%.In this material, the outcome of ceramic inlay therapy was influenced by both major and minor complications (35%). Eight of the 51 patients accounted for all the major fractures, implying that patient selection is an important determinant of the clinical outcome.

As different implant abutments are introduced to obtain a sufficient soft tissue barrier, the aim of this study was to determine the effect of three different surface modifications of densely sintered high-purity aluminium oxide on morphology, attachment and proliferation of human gingival fibroblasts. Fibroblasts were cultured on pressed aluminium oxide, milled, and then sintered to full density (1), on pressed, densely sintered (2), and on pressed, densely sintered and then polished surfaces (3). The different surfaces were analyzed using a confocal laser scanner, an atomic force microscope and a scanning electron microscope. The cell profile areas were measured using a semiautomatic interactive image analyzer and the figures were expressed as percent of attachment. The polished specimens had the smoothest surfaces and the roughest were the milled surfaces in terms of height deviation. No difference was found in the spacing between the peaks on the polished surfaces compared to the milled surfaces. Fibroblasts on the milled ceramic appeared to follow the direction of the fine irregularities on the surface. The analyses showed the polished surfaces had significantly higher percentages of initial cell attachment than the other surfaces (P

The surface roughness of an implant to which osteoblasts attach may influence endogenous expression of growth factor and cytokines at the implant-tissue interface, modulating the healing process and affecting the quality of bone formation. The present study, using cells derived from human mandibular bone, investigated the effect of varying roughness of titanium surfaces on production of transforming growth factor beta1 (TGF-beta1) and prostaglandin E2 (PGE2). The titanium surfaces were turned (control) and then roughened by blasting with 63-90 micro m, 106-180 micro m or 180-300 micro m TiO2 particles. The cells were cultured onto the surfaces till confluence was achieved. Fresh media were added in the presence or absence of 1,25-dihydroxyvitamin D3[1,25-(OH)2D3], the stimulator of osteogenic differentiation, and aliquots of conditioned cell media were used for assay 24 h later. Cellular morphology was determined by scanning electron microscopy. Cellular production of TGF-beta1 and PGE2 on each surface was assessed by enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay (RIA), respectively, using commercially available kits. All blasted surfaces showed significantly higher production of TGF-beta1 than the turned surfaces (P0.05). In response to stimulation by 1,25-(OH)2D3 cellular production of TGF-beta1, was also significantly greater (P0.05) on the blasted surfaces than on the turned one. The total amount of PGE2 in the conditioned media was higher than on the turned surfaces in the presence or absence of 1,25-(OH)2D3. There were no significant differences among the three blasted surfaces with respect to production of the local factors. However, we could not show a synergistic effect of surface roughness and vitamin D on the production of both TGF-beta1 and PGE2 using primary cell culture model.

This study evaluated the 5-year clinical and radiographic performance of fixed implant-supported maxillary prostheses with either welded titanium or conventional cast-gold alloy frameworks.Fifty-eight consecutive patients were provided with 349 osseointegrated Brånemark system implants in the edentulous maxilla at six different implant centers. Twenty-eight of the patients received, at random, prostheses with laser-welded titanium frameworks, and the remaining 30 patients had prostheses with conventional cast-gold alloy frameworks. Clinical and radiographic data were collected for 5 years after prosthesis placement.The titanium and cast-gold framework groups exhibited similar cumulative survival and success rates (CSR). The 5-year implant CSR from time of placement was 91.4% and 94.0%, respectively, and from prosthesis delivery the rate was 94.9% and 95.6%, respectively. The corresponding 5-year prosthesis CSRs were 96.4% and 93.3%. One patient from each group lost all the implants and turned to complete dentures within the first year of function. Another patient with a cast-gold framework had the prosthesis replaced after 4 years, basically because of problems with the veneering material. No fractures of implant components were observed during the follow-up period. Bone loss was on average 0.59 mm (SD 0.97 mm) during 5 years, with no statistical difference between the two groups.Welded titanium frameworks presented a similar favorable clinical performance as conventional cast-gold alloy frameworks in fixed implant-supported prostheses in the edentulous maxilla after 5 years in function. Implant failures were concentrated in only a few patients in each study group.

Variations in the oxide films on titanium surfaces blasted with TiO(2) particles of various sizes were analyzed after cultures with cells derived from human mandibular bone. Turned titanium surfaces and surfaces blasted with 63-90-, 106-180-, and 180-300-microm TiO(2) particles were cultured with osteoblast-like cells. The surfaces were characterized before and after the cell culture with electrochemical impedance spectroscopy (EIS). The surface chemical composition of selected samples was analyzed with X-ray photoelectron spectroscopy (XPS). EIS revealed that with respect to the turned surfaces, the effective surface area was about 5, 6, and 4 times larger on the surfaces blasted with 63-90-, 106-180-, and 180-300-microm particles, respectively. After 28 days of the cell culture, the corrosion resistance on all sample types was unaffected. The impedance characteristics suggest a considerable effect of ion incorporation and precipitation during culturing. XPS revealed that before the cell culture, a typical surface layer consisted of TiO(2). After the culture, the surface oxide film contained both phosphorus and calcium, along with large amounts of oxidized carbon (carbonate) and nitrogen. There were lower concentrations of carbon and nitrogen on the blasted surfaces. We concluded that the effective surface area was several times higher on blasted surfaces than on turned surfaces. Cells derived from human mandibular bone affected ion incorporation into the implant surface.

Statement of problem. The Composipost dowel is made of stretched, aligned carbon fibers embedded in an epoxy-resin matrix. It is widely used in Europe and Canada for the restoration of endodontically treated teeth and was introduced in the United States 2 years ago as the C-Post dowel. Purpose. This retrospective study evaluated treatment outcome of the Composipost system after 2 to 3 years. Material and methods. A total of 236 patients treated during a 1-year period by seven Swedish dental practitioners were included. Of those, 146 patients consented and data were collected from the dental records of the remaining patients. Thus, the material comprised 236 teeth restored with carbon fiberreinforced epoxy resin post, 130 maxillary and 106 mandibular teeth, with a mean restoration time of 32 months (range 27 to 41). Periodontal conditions, radiographic signs, and prosthodontic results were recorded. Results. Five teeth (2%) had been extracted for reasons unrelated to the Composipost system. Periodontal conditions such as plaque accumulation, gingival health, bleeding on probing, and pocket depth around the teeth with Composipost dowels were similar to the control teeth. No dislodgment or root or post fractures were observed clinically or on radiographs. Radiographic examination of bone height measured from the apex to the bone margin mesially and distally showed differences on the mesial side but not on the distal surface ( p Conclusions. Promising results after 2 to 3 years of clinical service indicate that this system can be a viable alternative to conventional post-and-core systems. (J Prosthet Dent 1998;80:151-7.)

Background Current conflicting information on the innervation of the human oral cavity indicates technical problems such as different detectability of the neural structures according to the various staining methods used and difficulties in reproducibility. The possibility of intraoral regional differences has not been properly considered. Methods Human biopsies of mucosa from different intraoral regions were prepared for immunohistochemistry using protein gene product 9.5 (PGP 9.5; a marker for neuronal structures). Results Nerves were found consistently in all the biopsies. The neural pattern showed clear regional differences. Intraepithelial nerve fibers were found in the gingiva, labia, palate, within certain fungiform papillae, and in some salivary excretory ducts. Organized nerve endings were found in varying frequencies in all but one (sublingual) region, appearing as lamellar (Meissner-like), coiled or glomerular neural structures. Merkel cell-neurite complexes were observed in the buccal, gingival, and palatal epithelia. Immunoreactive cells with many similarities to Merkel cells but without a neural connection were also encountered. Conclusions Conflicting results from earlier innervation studies of the oral cavity could be attributed to regional innervation differences. The distribution of the nerves also casts doubt on some of the present theories concerning the function(s) of intraoral nerves, such as the free nerve endings and the Merkel cell-neurite complexes. © 1996 Wiley-Liss, Inc.

The presence of distribution of several neurochemical markers in human fungiform papillae and taste buds were investigated by the immunohistochemical technique. The gustatory cells of the taste buds are in synaptic contact with sensory nerve endings, and considering the taste buds strictly as specialized sensory organs, the amounts and distribution of some of the neurochemical markers were different to what we expected. For example, few structures showed immunoreactivity to the tachykinins substance P (SP), calcitonin gene-related peptide (CGRP), and neurokinin A (NKA) also for the peptides vasoactive intestinal polypeptide (VIP), neuropeptide tyrosine (NPY) and galanin, low amounts of immunoreactivity occurred. On the other hand, using antibodies to protein gene product 9.5 (PGP 9.5), protein S-100, and glutamate, numerous nerve fibres and/or immunoreactive cells were found in the fungiform papillae, in the epithelium, in the connective tissue and around blood vessels, as well as in or near taste buds. Incubation with the antibodies against somatostatin, enkephalin, bombesin, peptide histidine isoleucine amide (PHI), cholecystokinin (CCK)/gastrin and dopamine-beta-hydroxylase (DBH) was negative for the fungiform papillae. In conclusion, the present study has shown several immunoreactive structures using antibodies against certain neurochemical markers. Further investigations will hopefully correlate these morphological findings with functional taste perception data. Future studies of patients with taste disorders or other pathological changes correlated with taste and tongue will also be of utmost importance.

With the aim of establishing conditions applicable to the testing of dental materials in human target cells, fibroblastic cell lines have been derived and grown from explants of human oral mucosa. Both a high-serum medium (termed "HSM") (CMRL 1066 supplemented with 10% fetal bovine serum) and a low-serum medium (termed "LSM") (a 1:1 mixture of M 199:MCDB 153 supplemented with 1.25% serum) supported radial outgrowths of cells from oral explants, as well as the subsequent transfer and growth of the cells in mass culture and at clonal density. Cells were typically fibroblastic in that they expressed vimentin uniformly, but did not express immunocytochemical markers of epithelial or endothelial cells. Cells derived in either LSM or HSM showed significantly higher colony-forming efficiency and clonal growth rate when transferred in LSM, as compared with HSM. Because cell migration occurred to a lesser extent in LSM, microscopic scoring of colony formation was also markedly facilitated. In both LSM and HSM, cellular low-molecular-weight thiols constituted about 30% of the total amount of sulfhydryls. Glutathione was present in about six- to seven-fold-higher amounts than cysteine-glutathione primarily in its reduced form and cysteine primarily in its oxidized form. A corrosion product of dental amalgam, i.e., Hg2+, decreased cell survival measured as colony-forming efficiency in a dose-dependent manner following either an acute (one h) exposure or continuous exposure (seven days). These studies demonstrated that human oral fibroblasts could be cultured at about one-tenth of the serum content that is commonly used. It is concluded that human oral fibroblasts grown at low-serum conditions provide a highly sensitive and easily applicable in vitro model for toxicity studies of dental materials.

— The content and distribution of metallic ions on the surface of gold-plated brass screwposts (Dentatus and MecOdont) were analyzed by X-ray microanalysis. On screwposts from one of the manufacturers the protective outer layer of gold was found to be localized to specific areas of the posts, i.e. the grooves, while unprotected Cu-Zn alloy was found on the ridges. The results are discussed with regard to results on root posts published earlier. Screwposts constructed in this way would appear to be of doubtful clinical value.