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Notes: Few investigations have studied the long-term fate of bone formed following the technique of guided tissue regeneration. The aim of the present study was to evaluate bone fill around implant fixtures with dehiscence defects and to study its response to loading. Ten patients were treated with overdentures supported by 2 fixtures ad modum Brånemark. A third 7 mm x 3.75 mm diameter fixture was placed for the purposes of the study in the most anterior part of the mandible with a dehiscence defect of 4 to 5 mm on the buccal aspect (and 3 to 4 threads exposed) which was covered with a Gore-Tex membrane and buried beneath the mucosa. Fixtures were exposed after 5 months (stage 2), ball abutments connected and loaded through an overdenture for 1 year. Nine fixtures were functioning well after 1 year of loading, 6 of which were retrieved with a trephine for histological examination and compared with 6 unloaded fixtures retrieved in our previously reported study. The bone area filling the thread profiles (BA%) and the bone to metal contact (BMC%) were measured in the 3 most apical and 3 most coronal thread profiles on the buccal and lingual surfaces. Statistically significant higher BMC% (P〈0.01) were observed in loaded fixtures in the apical regions (buccal: loaded 51%. unloaded 25%; lingual: loaded 49%, unloaded 24%). Differences approached significance for the regeneration site (loaded 22%, unloaded 6%) but were no different for the coronal lingual region (loaded 28%, unloaded 20%). There were no differences for BA%. This study confirms that there is an increase in bone to metal contact with time and following fixture loading and that this may also occur with bone regenerated under Gore-Tex membranes.

Notes: Abstract: Objective: The aims of this study were (i) to assess the morphological features of osteo-blast-like, osteosarcoma cells (cell line SaOS-2) cultured on implant surfaces of varying alloys and (ii) to evaluate the biological activity of these cells, following their adhesion onto these surfaces. Material and methods: SaOS-2 cells (6 × 104) were grown on titanium discs (diameter 30 mm), each with a surface of differing composition and roughness (commercially pure titanium, titanium-aluminium-vanadium alloy, oxide-blasted titanium and Astra-Tech special treatment titanium; the alloys are directly comparable with those used to construct implants). The cells were grown for time periods of 1, 3, 5 and 7 days, the media were collected and the cells were fixed with 2.5% glutaraldehyde. The media were then assayed (using enzyme-linked immunosorbant assay) for the levels of interleukin (IL)-1, interleukin-6, interleukin-18 and osteoprotegerin (OPG) produced by the cells. The discs, with the cells fixed on them, were viewed under scanning electron microscopy (SEM, × 2.0 k) to evaluate cell morphology. Results: Following attachment, the cells changed their morphology and released local factors known to activate osteoclasts. Commercially pure titanium stimulated the cells the most and titanium-aluminium-vanadium alloy the least. All implant materials stimulated production of IL-1, IL-6, IL-18 above that produced by cells grown on Petri dishes (polystyrene). The titanium-aluminium-vanadium alloy allowed cell attachment but levels of IL-1 in this medium were significantly lower (31.5 ± 5.2 pg/ml on same day) than cultures with pure titanium (201.8 ± 11.5 pg/ml at day 5). The same pattern was observed with the IL-6, IL-18, and OPG with polystyrene appearing to stimulate most production of OPG. Titanium-aluminium-vanadium produced the least biological response.

Notes: Aim— To evaluate the AstraTech Implant ST (Molndal, Sweden) for single tooth replacement clinically and radiographically after 5 years in function. Subjects and method— Fifteen patients (age range 16 to 48) with missing maxillary anterior teeth (6 central incisors, 8 laterals, 1 bicuspid) had four 13 mm and eleven 15 mm single tooth implants provided. All patients were seen at 4- to 6-monthly intervals for oral hygiene maintenance. Periapical radiographs using Rinn holders and a long cone technique were taken at the crown insertion and after 1 year, 3 and 5 years. Results— No implant losses were observed in 14 of the 15 patients available for evaluation. No abutment screw loosening or soft tissue problems were observed. At crown insertion the mean bone level was 0.46±0.55 to 0.48 ±0.56 mm apical to the top of the implant neck and there were no statistically significant changes in the radiographic bone level over the 5 years of the study (0.36±0.37 to 0.43±0.46 mm at year 5). One crown was recemented after 18 months in function and 1 crown was replaced because of a fracture to the porcelain incisal edge. Conclusion— The Astra Tech Implants ST were highly successful in single tooth replacement and bone levels during 5 years of function were stable.〈section xml:id="abs1-1"〉〈title type="main"〉RésuméLe but de cette étude a été d'évaluer cliniquement et radiologiquement le système Astra Tech Implant ST pour le remplacement d'une dent, après cinq années en fonction. Quinze patients de seize à 48 ans avec une dent antérosupérieure manquante (six incisives centrales, huit latérales et une prémolaire) ont été implantés avec quatre implants de 13 mm et onze de 15 mm. Tous les patients ont été revus à des intervalles de quatre à six mois pour l'entretien de l'hygiène buccale. Des radiographies périapicales utilisant la méthode de Rinn avec long cône ont été prises lors de l'insertion de la couronne et après une, trois et cinq années. Aucune perte implantaire n'a été observée pour quatorze parmi les quinze patients. Aucune vis de l'implant ne s'est dévissée et aucun problème de tissus mous n'a été observé. Lors du placement de la couronne, le niveau osseux moyen était de 0.46±0.55 à 0.48 ±0.56 mm apicalement par rapport au sommet du col de l'implant. Il n'y avait aucune variation statistiquement significative pour les niveaux osseux radiographiques durant les cinq ans à la fin desquels ces mesures étaient respectivement de 0.36±0.37 à 0.43 ±0.46 mm. Une couronne a été rescellée après 18 mois. Une autre a été remplacée suite à une fracture du bord incisif en porcelaine. Le système implantaire Astra Tech ST s'est révélé excellent pour le remplacement unitaire, les niveaux osseux durant les cinq années de fonction sont restés stables.〈section xml:id="abs1-2"〉〈title type="main"〉Zusammenfassung Ziel: Das Astra Tech Implantat ST (Molndal Sweden) über einen Zeitraum von 5 Jahren in Funktion klinisch und radiologisch zu untersuchen. Material und Methode. 15 Patienten (Alter zwischen 16 und 48) mit fehlenden Zähnen in der Oberkieferfront (6 zentrale Inzisiven, 8 laterale Inzisiven, 1 Prämolar) wurden vier 13 mm und elf 15 mm lange Einzelimplantate eingesetzt. Alle Patienten wurden alle 4 bis 6 Monate nachkontrolliert und die Mundhygiene überwacht. Nach dem Einsetzen der Kronen und 1 Jahr, 3 und 5 Jahre nach dem Einsetzen der Kronen wurden periapikale Röntgenaufnahmen mit dem Filmhaltern des Rinnsystems und der Langtubustecknik aufgenommen. Resultate: Bei den 14 von insgesamt 15 Patienten, welche nachuntersucht werden konnten, war kein Implantatverlust zu verzeichnen. Es konnten keine lockeren Schrauben bei den Prothetikaufbauten und keine Probleme an den Weichgeweben beobachtet werden. Beim Einsetzen der Kronen lag das Knochenniveau 0.46±0.55 bis 0.48±0.56 mm apikal vom Oberteil des Implantathalses und es fanden während der 5 Jahre dauernden Beobachtungszeit keine statistisch signifikanten Veränderungen im radiologischen Knochenniveau statt (0.36±0.37 bis 0.43±0.46 mm nach 5 Jahren). Eine Krone musste nach 18 Monaten in Funktion rezementiert und eine Krone wegen einer Porzellanfraktur der Inzisalkante ersetzt werden. Schlussfolgerung: Die Astra Tech Implantate ST waren für den Einzelzahnersatz sehr erfolgreich und die Knochenniveaus waren während der Beobachtungszeit von 5 Jahren in Funktion stabil.〈section xml:id="abs1-3"〉〈title type="main"〉Resumen Intencion— Evaluar clínica y radiograficamente el implante Astra Tech ST (Molndal Suecia) para sustitución de diente único tras 5 anos en function. Sujetos y metodo− 15 pacientes (rango de edad de 16 a 48) con ausencia de dientes maxilares anteriores (6 incisivos centrales, 8 laterales, 1 bicúspide) recibieron cuatro implantes unitarios de 13 mm y once de 15 mm. Todos los pacientes fueron vistos con intervalos de 4 a 6 meses para mantenimiento de higiene oral. Se tomaron radiografías périapicales usando soportes Rinn y técnica de cono largo en el momento de inserción de la corona y al año, 3 y 5 anõs. Resultados— No se observaron pérdidas de implantes en 14 de los 15 pacientes disponibles para la evaluación. No se observaron movilidades en los pilares o problemas de los tejidos blandos. En el momento de insertion de la corona el nivel medio de hueso fue de 0.46±0.55 a 0.48±0.56 mm apical de la parte alta del cuello del implante y no hubo cambios estadísticamente significativos en el nivel radiográfico de hueso a lo largo de los 5 años del estudio (0.36±0.37 a 0.43±0.46 mm en el quinto año). Una corona se recementó después de 18 meses en función y una corona se sustituyó por fractura de la porcelana en el borde incisai. Conclusion— Los implantes Astra Tech ST fueron altamente exitosos en la sustitución de dientes unitarios y los nivelés de hueso a los 5 años se mantuvieron estables.

Notes: Abstract: Objectives: To investigate the clinical and psychological outcomes with ball attachment supported mandibular overdentures on Branemark implants placed in a single stage surgical approach. Material and method: Sixteen edentulous patients aged 32–74, with atrophic (flat) mandibular residual alveolar ridges, and a history of having difficulty coping with technically adequate mandibular dentures made within the last 2 years were recruited. Mark II Branemark implants were placed using a single stage surgical technique with healing abutments placed at time of surgery. Mandibular complete dentures were modified by relieving the areas over the abutments and a resilient liner was placed. After a period of 3 months, healing abutments were replaced with ball abutments and new complete dentures were made and the patients followed for a period of 2 years. Patients completed the General Health Questionnaire (GHQ) and answered further questions relating to the functional and psychological impact of complete denture wearing before treatment and 3 months after the dentures were provided. Patients additionally completed the GHQ 2 years after overdenture insertion. Results: Six patients suffered from loss of one of their two implants in the first 2 years after placement. Three of the implants had failed to osseointegrate, which was detected at initial loading 3 months after placement. General Health Questionnaire scores were statistically significantly reduced after treatment and the improvement was maintained over 2 years. Responses to the functional and psychological questions were similarly improved. Conclusion: Single stage surgery led to a higher rate of implant failure than expected. Patients showed significant psychological health benefits from the treatment provided.

Notes: Aim: To review the potential biological mechanisms underlying the effects of tobacco smoking on periodontitis.Main findings: Smoking has major effects on the host response, but there are also a number of studies that show some microbiological differences between smokers and non-smokers.Smoking has a long-term chronic effect on many important aspects of the inflammatory and immune responses. Histological studies have shown alterations in the vasculature of the periodontal tissues in smokers. Smoking induces a significant systemic neutrophilia, but neutrophil transmigration across the periodontal microvasculature is impeded. The suppression of neutrophil cell spreading, chemokinesis, chemotaxis and phagocytosis have been described. Protease release from neutrophils may be an important mechanism in tissue destruction. Tobacco smoke has been found to affect both cell-mediated immunity and humoral immunity. Research on gingival crevicular fluid has demonstrated that there are lower levels of cytokines, enzymes and possibly polymorphonuclear cells in smokers. In vitro studies have shown detrimental effects of nicotine and some other tobacco compounds on fibroblast function, including fibroblast proliferation, adhesion to root surfaces and cytotoxicity.Conclusion: Tobacco smoking has widespread systemic effects, many of which may provide mechanisms for the increased susceptibility to periodontitis and the poorer response to treatment.

Notes: Summary A panel of antibodies has been used in an immunoenzyme study in an attempt to characterize the cell types found in the ‘epimyoepithelial’ islands of lymphoepithelial lesions. Myoepithelial cells, which can be specifically stained with ah anti-smooth muscle antibody were not found. The majority of cells stained with anti-prekeratin, suggesting a duct cell differentiation. A subpopulation of duct cells stainable with a monoclonal antikeratin (16a), previously described as occupying a basal location in normal salivary gland ducts, was clearly demonstrated. It is suggested that these cells may be important in the epithelial proliferation in these islands. The hyaline material within and surrounding the epithelial islands was positive for type IV collagen and therefore consists of basement membrane material.

Notes: Summary The cellular changes in salivary gland parenchyma with chronic inflammation were studied immunocytochemically with a panel of antibodies. Myoepithelial cells were labelled with antimyosin, duct cells with a polyclonal anti-callus prekeratin, a monoclonal anti-keratin CAM 5.2 and a monoclonal anti-keratin 7 (RPN 1162), and a subpopulation of basal duct cells with a monoclonal anti-keratin 16 a. The wide range of changes observed were similar to those described following experimental duct ligation. One of the most striking features was the survival of myoepithelial cells surrounding persisting acini and ductal structures. Most of these ductal structures appeared to be either surviving intercalated ducts or were altered acinar cells. There was no evidence of myoepithelial or ductal hyperplasia. The 16a positive basally located duct cells which are conspicuous in normal glands, pleomorphic adenomas and in the epithelial islands in lymphoepithelial lesions (Palmer et al. 1985; 1986) were virtually absent, except in one specimen with mild inflammatory changes. If this cell type represents a reserve cell, then loss of it may preclude recovery of the remaining parenchyma following resolution of inflammation.