bluuebunny/crossref_metadata_2025 huggingface dataset:
Outcome after treatment of congenital bilateral cataract
Authors: Lundvall Anna , Kugelberg Ulla
Published: March 2003

Purpose:  To evaluate long‐term functional outcome after treatment of dense congenital bilateral cataract.

Methods:  The records of 22 consecutive children operated on before the age of 12 months at St. Erik's Eye Hospital over a 5‐year period (1991–96) were reviewed retrospectively. Linear Snellen visual acuity (VA) at last check, presence of stereoacuity, nystagmus, strabismus and other complications are accounted for. Subject age at last check ranged from 4 to 9 years.

Results:  Visual acuity could be estimated in 19 children: the median VA of the better eye was 0.4 (range: counting fingers − 0.8) and of the fellow eye 0.15 (range: amaurosis − 0.8). In nine otherwise healthy children who were operated on early (by 1 month of age), VA varied from 0.4 to 0.8 in the better eye. Four of these children achieved stereopsis. Pupillary block glaucoma developed in five eyes (in three children). Chronic glaucoma developed in eight eyes (in five children). Glaucoma occurred predominantly in children who underwent cataract extraction during the first week of life. Two of the latter had marked microphthalmos.

Conclusion:  Good postoperative VA was achieved in most healthy children with dense bilateral congenital cataract when surgery was performed early (before 6–8 weeks of age). Chronic glaucoma developed predominantly when cataract extraction was performed during the first week of life.
A longitudinal study of visual acuity and visual rehabilitation needs in an urban Swedish population followed from the ages of 70 to 97 years of age
Authors: Bergman Birgitta , Sjöstrand Johan
Published: March 2003

Purpose:  To investigate the longitudinal change in visual acuity (VA) in the oldest members of the elderly population, to estimate future numbers of people with visual impairments, and to estimate needs for and the effects of visual rehabilitation.

Methods:  In the Gerontological and Geriatric Population Studies in Gothenburg, Sweden (H 70), subjects underwent repeated eye examinations at the ages of 70, 82, 88, 95 and 97 years. Logistic regression analysis was used to estimate the probability of independent living as a function of distance VA at different ages.

Results:  Rates of normal VA (≥ 0.8) declined from 86% of the study group at age 70 to 7% of the study group at age 95 (0% at age 97). The incidence of VA ≤ 0.1 increased from 1.4% at age 70 to 27% (all women) at age 97. The deterioration was faster at higher ages. No statistically significant difference in best‐corrected distance VA between genders was found. A substantial improvement was achieved by correcting refractive errors. There was a statistically significant correlation between distance VA and the probability of independent living at all ages except age 97. At ages 95 and 97, about 50% of the study group were able to read newspaper print with best‐corrected glasses.

Conclusions:  The number of old people with impaired vision will increase. People aged 80 years and older should have regular eye‐screening in order to preserve vision and present conditions of living. Cataract surgery and low vision rehabilitation should be offered when the subject can still benefit from it, preferably during their 80s at the latest.
Detection of herpes simplex virus in pseudoexfoliation syndrome and exfoliation glaucoma
Authors: Detorakis E. T. , Kozobolis V. P. , Pallikaris I. G. , Spandidos D. A.
Published: March 2003

Purpose: The pathogenesis of pseudoexfoliation syndrome (PEX) remains unknown. An infection, possibly viral, is one of the proposed pathogenetic mechanisms. This study examines the presence of herpes simplex virus (HSV) and varicella‐zoster virus (VZV) in iris and anterior capsule specimens of PEX and non‐PEX patients.

Methods: Iris and anterior capsule specimens were obtained from 64 patients with PEX (study group, SG) and 61 patients without PEX (control group, CG). The presence of HSV and VZV DNA was evaluated with a polymerase chain reaction (PCR).

Results: Herpes simplex virus type I was detected significantly more often in iris specimens from the SG (13.79%), compared to those from the CG (1.75%). Varicella‐zoster virus DNA was not detected in any of the examined specimens.

Conclusion: Results imply a possible relationship between HSV type I and PEX, although no aetiological role of HSV infection in PEX pathogenesis can be established. Results also advocate against any association between VZV and PEX.
Evaluation of VEP perimetry in normal subjects and glaucoma patients
Authors: Bengtsson Boel
Published: March 2003

Purpose:  To estimate sensitivity to glaucomatous visual field loss using multifocal visual evoked potential (VEP) perimetry, to compare these findings to those of conventional achromatic perimetry and to determine specificity of VEP perimetry in normal subjects.

Methods:  A total of 33 glaucoma patients with known visual field defects in at least one eye on standard computerized perimetry and 33 healthy subjects were tested with VEP perimetry. The glaucoma patients were also tested with standard computerized perimetry using the 30–2 SITA Fast program of the Humphrey Field Analyzer (HFA). Visual evoked potential perimetry classification and VEP probability maps were used to determine the sensitivity and specificity of the technique.

Results:  Visual evoked potential perimetry classified 68% of all eyes in the glaucoma group (45/66) as pathological; sensitivity increased to 81% (38/47) when considering only those eyes with HFA field defects. It also identified more test locations with significant loss at the p < 5% level in both groups (48% and 37%, respectively) than did HFA, while HFA identified more loss at the higher significance levels p < 2%, and p < 1%. Visual evoked potential perimetry showed more significant loss in eyes with almost normal or slightly damaged standard fields, while HFA identified more significant field loss in eyes with severe conventional field damage. The mean VEP amplitude of the 66 glaucoma eyes was 1.461e−7 V; it was 1.676e−7 V for the 66 control eyes. This difference was significant (p = 0.0033), but the overlap between groups was large. Visual evoked potential perimetry classified 42% of the control eyes as ‘outside normal limits’, and VEP probability maps showed 30.0% of test segments as significantly depressed at the p < 5% level, 10.8% of sites at p < 2%, and 4.6% at the p < 1% level.

Conclusion:  Mean VEP amplitude differed significantly between normal and glaucoma eyes, but the overlap was considerable. Visual evoked potential perimetry falsely classified a large number of normal eyes as pathological and showed many more significantly depressed test locations than expected. Agreement between VEP and standard perimetry was relatively poor for the glaucoma group. Further refinements are needed before VEP perimetry can be regarded as a reliable clinical method of mapping glaucomatous visual fields.
Terson's syndrome presenting as an ophthalmic emergency
Authors: Murthy Shashidhar , Salas David , Hirekataur Srinivas , Ram Raghu
Published: March 2003

Purpose:  To report an unusual case of Terson's syndrome caused by a ruptured intracranial aneurysm presenting as an ophthalmic emergency with visual loss, without any neurological features at the time of presentation.

Methods:  Case report. A 38‐year‐old man was referred to the eye emergency department with sudden loss of vision in both eyes. Vitreous haemorrhage was noted in both eyes. There was no history of loss of consciousness or headaches and no signs of meningeal irritation at presentation. The patient subsequently developed progressive neck stiffness and headache.

Results:  Neuro‐imaging studies revealed a subarachnoid haemorrhage resulting from a ruptured carotid‐ophthalmic artery aneurysm.

Conclusions:  It is important to consider Terson's syndrome, a potentially life‐threatening condition, in any patient presenting with bilateral vitreous haemorrhage. Some patients may not show any headache, neurological deficits or signs of meningeal irritation at presentation but may develop them later on.
Infectious salmon anaemia virus
Authors: Rimstad Espen , Mjaaland Siri
Published: March 2003

Infectious salmon anaemia virus (ISAV) is a commercially important orthomyxovirus causing disease in farmed Atlantic salmon. The cumulative mortality in a net pen during an outbreak may vary from insignificant to more than 90%. The infection is spread by management activity such as well‐boat traffic, but possibly also through contact with wild fish. In many of its aspects, including the structure of the virus particle and replication strategy, the ISAV is similar to the influenza viruses. Variations between ISAV and the influenza viruses can mostly be related to differences in the temperature at which replication occurs and the immune response of their respective host animals. ISAV shows both haemagglutinating and receptor‐destroying activity. The variability of the ISAV haemagglutinin molecule is concentrated around a small domain close to the transmembrane region. The function of this variable region is unknown, but it may be related to a recent or ongoing crossing of a species barrier. Alignment studies based on genetic data indicate that the phylogenetic relationship to the influenza viruses is distant, and that ISAV therefore could possibly warrant a new genus within Orthomyxoviridae.
Conditions influencing the in vitro antifungal activity of lactoferrin combined with antimycotics against clinical isolates of Candida
Authors: Kuipers M. E. , Beljaars L. , Van Beek N. , De Vries H. G. , Heegsma J. , Van Den Berg J. J. M. , Meijer D. K. F. , Swart P. J.
Published: March 2003

Lactoferrin, an iron‐binding glycoprotein, is a potential agent for the treatment of oropharyngeal Candidiasis. The aim of the present study was to test the capability of lactoferrin, combined or not combined with conventional antifungal agents, to inhibit the growth of different Candida species under various experimental conditions to be of guidance in the development of a suitable pharmaceutical formulation containing lactoferrin. The anti‐Candida activities of lactoferrin were considerably higher using RPMI instead of SLM as assay medium. They were moreover increased by raising the medium pH from 5.6 to 7.5. With the ‘standard’ antifungal agent fluconazole similar results were found as for lactoferrin, but the medium type and pH did not affect MIC values of amphotericin B. The addition of saliva to medium did not reduce the antifungal activities of the individual compounds. Synergistic inhibitory effects on Candida growth were found for combinations of lactoferrin and fluconazole or amphotericin B, irrespective of the medium type and pH, or the addition of saliva. This indicates that for treatment of oral Candidiasis a formulation containing lactoferrin seems appropriate; results may be optimized if the formulation is provided with buffer capacity to attain pH 7.5 in the mucosal fluid. The synergistic effects between lactoferrin and ‘standard’ antifungals indicate that combinations should be considered in such a formulation.
Synergistic effects of 1,25‐Dihydroxyvitamin D3 and TGF‐β1 on the production of insulin‐like growth factor binding protein 3 in human bone marrow stromal cell cultures
Authors: Kveiborg M. , Flyvbjerg A. , Kassem M.
Published: March 2003

1,25‐Dihydroxyvitamin D3 (calcitriol), transforming growth factor‐β (TGF‐β), and insulin‐like growth factors (IGFs) are all important bone regulatory factors known to affect proliferation and differentiation of human bone‐forming cells (osteoblasts). We have previously shown that TGF‐β1 increased IGF‐I and IGF‐binding protein (IGFBP)‐3 production in human bone marrow stromal (hMS) osteoblast progenitors and calcitriol stimulated IGFBP‐3 and IGFBP‐4 production. As interaction between signaling pathways of these factors has been reported, the present study aimed at examining the concerted actions on components of the IGF‐system. We report that co‐treatment with TGF‐β1 and calcitriol resulted in a synergistic increase in IGFBP‐3 production, thereby suggesting that the effects of these factors on hMS osteoblast differentiation may involve the observed increase in IGFBP‐3.
Activation of the p38 MAP kinase pathway is required for foam cell formation from macrophages exposed to oxidized LDL
Authors: Zhao Ming , Liu Yawei , Wang Xiaofei , New Liguo , Han Jiahuai , Brunk Ulf T.
Published: March 2003

Endocytosis of oxidized low density lipoproteins (oxLDL) by macrophages, mediated by scavenger receptors, is thought to play a central role in foam cell formation and, thus, in the pathogenesis of atherosclerosis. OxLDL activates several MAP kinases, including the ERK, JNK and p38 MAP kinases, but the role of these activations in oxLDL uptake has not been studied. In the present investigation, we find that SB203580, a specific inhibitor of p38, blocks oxLDL‐exposed J774 cells from becoming foam cells. Inhibition of foam cell formation by blockade of the p38 pathway is, at least in part, due to inhibition of oxLDL‐induced up‐regulation of the scavenger receptor CD36. Using pharmaceutical inhibitors and dominant active MAP kinase kinases, we demonstrated that activation of the p38 pathway, but not the ERK or JNK pathways, is necessary and sufficient to transactivate PPARγ, a nuclear receptor that has recently been shown to play a pivotal role in oxLDL‐induced CD36 expression. Our results for the first time demonstrate a regulation of CD36 by p38, and the importance of the p38 pathway in regulation of foam cell formation.
The flow cytometric DNA index can predict the presence of lymph node metastases in invasive ductal breast carcinoma
Authors: Mannweiler SEBASTIAN , Tsybrovskyy OLEKSIY , Regauer SIGRID
Published: March 2003

Axillary lymph node (LN) dissection is an important staging procedure for invasive ductal breast carcinoma (IDC), but causes elevated morbidity. Reliable preoperative prediction of metastases is at present not possible. We investigated whether flow cytometric analysis of primary IDC can correctly predict the presence of LN metastases at the time of primary diagnosis. In 341 primary IDC, DNA index (DI) in absolute values, S‐phase fraction (SPF), size of the primary tumor, tumor grade (G), estrogen/progesterone receptors (ER/PR) expression and age were analysed and correlated with the axillary LN status with the aim of correctly predicting the LN status. No predictive value was identified for S‐phase fraction (SPF), tumor grade, or ER/PR expression. The DI correlated statistically with LN status in all patients. A practically useful association was, however, only observed in 37 women aged 45–58 years with an IDC >2 cm diameter: a DI>1.44 predicted the presence of LN metastases at the time of operation with a specificity of 100% and a sensitivity of 89%, a negative predictive value of 91% and a positive predictive value of 100%. Determination of the absolute values of the DI may be a useful adjunct to sentinel LN preparation when predicting the axillary LN status and may spare some women the morbidity associated with axillary LN dissection.
Mixed microbial aetiology of community‐acquired pneumonia in children
Authors: Korppi MATTI
Published: March 2003

Seven paediatric studies on community‐acquired pneumonia with serological methods for both viruses and bacteria have been published, allowing the evaluation of concomitant multiple etiological findings. In these studies, dual viral infection has been present in 0–14%, dual bacterial infection likewise in 0–14%, and mixed viral‐bacterial infection in 3–30% of the pneumonia cases. The results confirm former clinical observations that respiratory viruses often pave the way for airway‐colonising bacteria. The measured frequency of multiple infections has been dependent on the available test panel, mainly on the tests used for pneumococcal aetiology. Mixed viral‐bacterial infections have been especially co‐mmon in young children under 2 years of age, reflecting the high frequency of respiratory syncytial virus infections and their tendency to induce bacterial co‐infections. No microbe‐specific viral‐bacterial associations have been demonstrated. The clinical implications of mixed viral‐bacterial infections, compared with viral infections alone or bacterial infections alone, have so far remained unresolved. Current guidelines recommend antibiotic therapy for all community‐acquired pneumonia cases in children.
Differences in prevalence, intensity of infection and parasite‐specific antibody levels do not predict different age‐infection profiles
Authors: Abebe F. , Gaarder P. I. , Petros B. , Gundersen S. G.
Published: March 2003

Acquired immunity is believed to influence the age‐infection profile of Schistosoma infections. We compared antibody responses against Schistosoma mansoni adult worm antigen (AWA) and soluble egg antigen (SEA) in 164 residents of two communities with different levels of infection. IgG, IgA, IgM, IgE, and IgG subclass 1 to 4 antibodies were determined by ELISA. Seventy‐five of the subjects were from Harbu, an area with a prevalence of 39% and an intensity of infection of 116 eggs per gram of stool (EPG), whereas 89 subjects were from Bati, with a prevalence of 66% and intensity of infection of 256 EPG. In both communities the prevalence and the intensity of infection were highest in the age group 10–14 years, although both were significantly higher in Bati than in Harbu. Mean levels of AWA‐specific IgA, IgM, IgG, IgG1 and IgG2, and of SEA‐specific IgG, IgM, IgG2 and IgG3 were significantly higher in Bati than in Harbu. However, mean levels of IgE against worm and egg antigens were significantly higher in Harbu than in Bati. Significant differences were detected in the levels of IgA, IgE, IgG, IgM, IgG1 and IgG2 against AWA, and in IgE, IgM, IgG2 and IgG3 against SEA according to the place of residence. The levels of anti‐AWA IgG, IgG1 and IgG2 and anti‐SEA IgG, IgGl and IgG4 were significantly associated with the intensity of infection. Anti‐AWA IgM levels were associated with age, whereas sex and age had interacting effects on the levels of AWA‐specific IgG1 and SEA‐specific IgG and IgM. Antibody responses exhibited different age‐related patterns in the two communities. This may indicate that differences in history of exposure influence the evolution of immune responses. However, the study did not support the view that differences in antibody levels between communities subject to different levels of infection result in a systematic deviation in age‐infection profile (the “peak shift”).
Acute xenograft rejection, late xenograft rejection and long term survival xenografts in the hamster‐to‐rat heart transplantation model: histological characterisation under low‐dose of FK506
Authors: GINESTÀ MIREIA MORELL , RIBAS YOLANDA , MOLLEVI DAVID G. , VIDAL AUGUST , MAÑEZ RAFAEL , FIGUERAS JOAN , JAURRIETA EDUARDO
Published: March 2003

Background. Long‐term survival studies have been conducted in hamster‐to‐rat cardiac models with a range of immunosuppressive treatments, but the histological pattern of Late Xenograft Rejection (LXR) has not been outlined. This study offers a detailed description of the histological changes in cardiac xenografts under three different immunological responses. Materials and methods. Heterotopic hamster‐to‐Lewis rat cardiac transplant. Recipients were administered an antiproliferative drug (MMF, 25 mg/kg, or CyP, 10 mg/kg, from day −7 to +7 or from day 0 to +7, according to group) and FK506 (0.2 mg/kg; from day 0 to +30 or continuously). Unmodified recipients were used as controls. Conventional histology and indirect immunofluorescence of IgM, IgG and C3 deposits were performed. Results. In our study, xenografted rats that did not receive treatment developed a pattern of Acute Xenograft Rejection (AXR), with substantial tissue breakdown. Pretreated and treated animals until day 30 post‐transplant developed LXR that may present two different histological patterns: one with vascular damage and predominant interstitial haemorrhage, and the other with extensive myocardial fibrosis. Long‐term surviving rats (LTS) showed a morphology that was almost normal, with mild fibrosis and vascular endothelium preserved. Conclusions. AXR, LXR and LTS in the hamster‐to‐rat heart transplantation model present a common humoral mechanism although their histopathological patterns are different depending on the length of immunosuppressive treatment but not on the type of antiproliferative drug administered. Pretreatment exerts an effect on fibrosis formation.
Microbiological features of stable osseointegrated implants used as abutments for overdentures
Authors: Mombelli A. , Mericske‐ster R.
Published: March 2003

The microflora associated with osseointegrated implants used as abutments for overdentures was investigated in 18 edentulous patients, 2 years after implantation. 52.8% of the organisms cultured were facultatively anaerobic cocci and 17.4% were facultatively anaerobic rods, while Gram‐negative anaerobic rods accounted for only 7.3%. Fusobacterium sp. and Bacteroides intermedius were both found in 8.8% of the samples. B. gingivalis and spirochetes were not found. Repeated microbiological and clinical data were collected in 9 patients during the 3rd, 4th and 5th year after implantation. No significant time trends were noted. Separate samples taken within the same patient from different sites were similar. Therefore, bacteriological independence of sites could not be assumed for the conditions investigated.
In vivo early human dental plaque formation on different supporting substances. A scanning electron microscopic and bacteriological study.
Authors: Siegrist B. E. , Brecx M. C. , Gusberti F. A. , Joss A. , Lang N. P.
Published: March 2003

Different studies have shown that various substances may have an influence on early human dental plaque formation. The purpose of the present study was to compare on tooth substances and supporting prosthetic materials the amount of plaque deposition by SEM and the quantity of selected bacteria using anaerobic culturing techniques. 5 bridges, replacing a missing molar or premolar, were incorporated in 3 patients. In the midbuccal area of each pontic, a semi‐precision attachment was placed allowing the insertion of the following test facings: enamel, dentine, non γ2‐amalgam, alloys of 85% and 55% gold, silver‐palladium, chrome‐cobalt, chrome‐cobalttitanium, and ceramic. For each material, 2 facings were fabricated. After 4 and 24 hours in situ, bacteriological samples were taken and processed for further identification. After a 2nd period of 4 and 24 hours in situ, the same facings were carefully removed and prepared for SEM‐examination. All 4‐hour specimens exhibited various areas covered by plaque, the amount of which varied with the different supporting substances. The very smooth surfaces (e.g., gold) harbored sparse deposits, while the rougher (e.g., amalgam) were covered by more plaque. After 24 hours of plaque development, an increase in the number of micro‐organisms was noted for all the specimens. After 4 and 24 hours of plaque accumulation, no specific trends suggesting a preferential colonization on the different substances were observed. This study has shown that the amount of early deposits on different substances seems to be related to the degree of their surface roughness, while plaque formation was qualitatively similar.
In vitro and in vivo experimental studies on single crystal sapphire dental implants
Authors: Arvidson K. , Fartash B. , Moberg L‐E. , Grafström R. , Ericsson I.
Published: March 2003

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 (a ‐αl,O,) 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 in‐serted 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.
Microbial differences in 2 clinically distinct types of failures of osseointegrated implants
Authors: Rosenberg E. S. , Torosian J. P. , Slots J.
Published: March 2003

The microflora associated with osseointegrated implants suspected of failing from infection or trauma were evaluated. Of 75 patients examined, 11 demonstrated failing fixtures. 22 of 48 fixtures failed in 6 fully edentulous patients and 10 of 34 failed in 5 partially edentulous patients. The etiology of failure was attributed to infection if there was bleeding, suppuration, pain, high plaque and gingival indices and granulomatous tissue upon surgical removal. Traumatic etiology was suspected in the absence of these signs. Direct phase‐contrast microscopy and culture analysis were performed on samples from the implant sulcus, the implant itself and the extraction socket. The 2 failure types exhibited distinct bacteriologic profiles. For implants failing with infection, spirochetes and motile rods averaged 42% of total morphotypes. Many suspected periodontopathic organisms including Peptostreptococcus micros, Fusobacterium species, enteric gram‐negative rods and yeasts, constituted high proportions of the cultivable microflora. In contrast, implants failing from suspected traumatic etiology demonstrated a morphotype profile consistent with periodontal health and cultivable microflora predominated by streptococci. When evaluating the time of failure after initial insertion, it was found that fixture loss resulting from infection occurred most often between initial placement and second‐stage surgery, whereas failure in the absence of infection occurred primarily after insertion of the final prosthesis. The terms infectious and traumatic failure have been introduced to describe these 2 clinically and microbiologically distinct phenomena.
A semi‐automated computer‐assisted method for measuring bone loss adjacent to dental implants
Authors: Reddy M. S. , Mayfield‐donahoo T. L. , Jeffcoat M. K.
Published: March 2003

The purpose of this study was to develop a repeatable method for measurement of bone support around root form and blade implants suitable for use in high‐quality but unstandardized radiographs. 10 phantoms were fabricated to simulate progressive osseous defects around implants. Radiographs were taken in triplicate and digitized. Specialized software was written which placed a grid of known dimensions over the implant so that the top and the bottom of the grid were at the neck and the base of the implant, respectively. The investigators selected the edge of the bone at each point where the grid intersected the implant and the software automatically detected the implant edge. The software also outlined and displayed the defect on the computer monitor. Measurements were performed 5 times and the standard deviation was taken as a measure of the repeatability of the method. Repeatability for blades and root forms was 0.19 ± 0.07 mm and 0.08 ± 0.03 mm, respectively. There was no significant difference in the ability to measure bone loss in the blade versus the root form (pequals;0.17, NS). These results indicate that this semi‐automated computer‐assisted method for measuring bone loss around implants is repeatable and may be of value for clinical trials using either root form or blade implants.
Evaluation of different methods to clean titanium abutments. A scanning electron microscopic study.
Authors: Speelman J. A. , Collaert B. , Klinge B.
Published: March 2003

The cleaning effectiveness of different treatment methods for titanium abutments was evaluated using scanning electron microscopy (SEM). In the mandible of 4 beagle dogs, 25 titanium abutments were installed (modum Brånemark). After 16 weeks of plaque accumulation, mineralized deposits had formed on 23 abutments. Each of these abutments was subjected to one of the following treatment methods: scaling with (1) metal, (2) plastic, or (3) ultrasonic instruments;(4) air‐polishing, (5) weekly rubber cup polishing or (6) daily brushing with a conventional toothbrush. Fourteen abutments were removed immediately after treatment. On 9 abutments, the scaling procedures and air‐polishing were repeated after another 16 weeks of plaque accumulation. The abutments were prepared for SEM, and each of them was viewed and photographed at 3 different magnifications. The photomicrographs were evaluated by 3 examiners who, guided by reference pictures, gave each abutment a “cleanliness” score, ranking from 0 to 5. Regular rubber cup polishing and regular brushing resulted in the highest surface cleanliness, while the air‐polishing procedure showed the lowest cleanliness score. None of the 3 scaling methods created a cleanliness score better than 3. The 3 scaling methods were considered equal in their cleaning effectiveness. No differences could be observed between surfaces treated 1 x or 2 x Taken the present findings and those of other studies concerning the effects of scaling on the surface roughness and biocompatibility into consideration, it was concluded that plastic scalers may be the instruments of choice for debridement of titanium implant surfaces.
Speech in connection with maxillary fixed prostheses on osseointegrated implants: a three‐year follow‐up study
Authors: Lundqvist S. , Haraldson T. , Lindblad P.
Published: March 2003

In 21 individuals, edentulous in the upper jaw, the speech function was evaluated. In an earlier study, registrations were made when the patients wore complete dentures in the upper jaw and 3–6 months after they had been treated with fixed prostheses on osseointegrated implants in the maxilla. These patients were re‐examined after 3 years, as reported in this follow‐up study. An expert group as well as a non‐expert group participated in a perceptual analysis. Acoustic, audiological and cast analyses were performed. In addition, a questionnaire was filled in. The results indicated that, after initial phonetic problems, 94% of the individuals considered themselves free from speech problems at the 3‐year follow‐up. The patients' experience of the change of the s‐sound corresponded well with the judgement of both the expert and the non‐expert groups. Difficulties with pronouncing the s‐sound were associated with decreased bite force, the number of occluding contacts, the frontal width of the fixed prosthesis and tenderness at palpation of the masticatory muscles. These oral functional factors will contribute to the s‐sound production.
A clinical and radiological two‐year follow‐up study of maxillary overdentures on osseointegrated implants
Authors: Smedberg J.‐I. , Lothigius E. , Bodin I. , Frykholm A. , Nilner K.
Published: March 2003

In order to satisfy the need to restore the aesthetics, phonetics and comfort and to facilitate optimal hygiene procedures, 20 edentulous patients were treated with a new concept of overdenture therapy on implants ad modum Brånemark. After 24±3.5 months the patients were re‐examined. They were asked to answer a questionnaire and use a Visual Analogue Scale (VAS) to give their opinion on the prosthetic treatment. The results indicate that an implant‐retained overdenture in the maxilla with this design can satisfy the patients needs in aesthetics, phonetics and comfort and can 1 facilitate oral hygiene measures.
Marginal tissue response adjacent to Astra Dental Implants® supporting overdentures in the mandible. A 2‐year follow‐up study.
Authors: Gotfredsen K. , Holm B. , Sewerin I. , Harder F. , Hjörting‐hansen E. , Pedersen C. S. , Christensen K.
Published: March 2003

The aim of this study was to evaluate the marginal tissue response adjacent to implant supported overdentures. Twenty edentulous patients had 2 Astra Dental Implants® placed in the canine region of the lower jaw. New overdentures were retained by individual ball attachments in 11 patients and by a bar attachment in 9 patients. Periodontal registrations were recorded 0 months, 6 months, 12 months and 24 months after the overdentures were inserted. One of the 40 fixtures was lost at the stage of abutment connection. No fixtures were lost during the 2‐ to 4‐year observation period and no fixtures showed any periodontal signs of failure. At the 2‐year examination, no pocket depths adjacent to the implants exceeded 4 mm and no bone loss exceeded 3 mm. The mean annual bone loss was less than 0.2 mm during the first 2 years. The preliminary results from this limited study were promising and showed that two osseointegrated Astra Dental Implants® could successfully retain an overdenture in the lower jaw. However, long‐term observation is needed for a definate evaluation of this treatment concept.
The surface analysis of implant materials. The surface composition of a titanium dental implant material.
Authors: Ameen A. P. , Short R. D. , Johns R. , Schwach G.
Published: March 2003

The surfaces of titanium (Ti) plates, as models for Ti implants, have been characterized by X‐ray photoelectron spectroscopy (XPS) and time‐of‐flight secondary ion mass spectrometry (TOF SIMS). Plates were prepared with rough and smooth surface topographies ‐ the rough being similar to that of an implant. The XPS data has been used to construct a model of the plates' surface chemical structure, from the gas‐solid interface through to pure Ti metal. At the surface of as‐received plates, which underwent the same preparative procedure as an implant, considerable surface contamination was detected. In particular, high levels of carbon (C) contaminants were detected; the nature of this C was elucidated by fitting the C 1s core line and from the secondary ion mass spectra. The oxygen (0) 1s core line could not be fitted using a minimum of 2 gaussian peaks, demonstrating the multiplicity of 0 environments. The detection of other elements in the XPS analysis further demonstrated that, in nominally pure Ti plates, the surface chemical composition deviates considerably from that of the bulk. The data obtained from the plates were confirmed by examination of a Ti abutment. The handling of Ti plates with stainless steel tweezers was investigated. No obvious change in surface chemistry was detected. All the above results bring into serious questions the validity of rigorous protocols demanded, in some techniques, in the 1 handling and use of Ti implants.
Peri‐implant mucosal aspects of ITI implants supporting overdentures. A five‐year longitudinal study.
Authors: Mericske‐stern R. , Steinlin Schaffner T. , Marti P. , Geering A. H.
Published: March 2003

Sixty‐six ITI implants placed in the mandible of 33 edentulous elderly patients (mean age: 69 years) were observed longitudinally for 5 years. The implants served as overdenture anchorage either by means of a connecting bar or single spherical attachments. During the study period, 2 implants failed (one because of a peri‐implant lesion and one because of a fracture) and had to be removed. At the beginning of the study, all implants were osseointegrated and had successfully been in function for 335 months. Oral hygiene practices and the peri‐implant mucosal status were assessed according to the criteria of conventional periodontal parameters. Approximately 50% of the implants had been installed into lining mucosa and hence were to surrounded by keratinized mucosa. The peri‐implant mucosal tissue was maintained healthy during the whole observation period, and no or only minimal loss of attachment was observed. The probing depths averaged approximately 3 mm. At the end of the study, orthopantomographic radiographs were obtained from all patients to assess the peri‐implant bony structures. Small local angular bony defects were detected on 16 implants (22%) in 12 patients. Slightly increased probing depths were observed when angular bony defects were present. Loss of attachment was significantly less frequent when the implants had been placed following a prolonged period of edentulousness (<5 years). This study demonstrated that advanced age, reduced dexterity of elderly patients and environmental conditions of overdentures do not represent a 1 higher risk for the development of peri‐implant lesions.
Augmentation of intramembraneous bone beyond the skeletal envelope using an occlusive titanium barrier. An experimental study in the rabbit.
Authors: Lundgren D. , Lundgren A. K. , Sennerby L. , Nyman S.
Published: March 2003

The aim of this investigation was to evaluate whether augmentation of intramembraneous bone beyond the skeletal envelope can be predictably achieved by placing a completely occlusive barrier on the skull bone of rabbits, hereby creating a secluded space with bone tissue being the only adjoining tissue. The experiment was carried out in 3 New Zealand white rabbits. In each animal, a midline incision was made down to the bone surface of the skull and a skin‐periosteal flap was raised to expose the skull bone on both sides of the midline. Two prefabricated titanium domes with an inner diameter of 4.5 mm and an inner height of 3.0 mm were installed on each side. The domes were supplied with a horizontal, peripheral flange and a vertical edge, fitting tightly into a circular slit, prepared by a trephine into the skull bone. This arrangement ensured a stable anchorage of the dome and a reliable peripheral sealing of the space. The skin‐periosteal flaps were relocated to cover the domes and sutured. After a healing period of 3 months, the animals were killed and the experimental areas excised and prepared for histological transversal ground sections with each dome in situ. The results demonstrated complete bone fill of all domes, with no signs of ingrowth of other types of tissues, indicating that the use of a barrier with total occlusiveness, sufficient stiffness and stability and reliable peripheral sealing will result in predictable bone augmentation of spaces also beyond the skeletal envelope.
Radiographical and histological characteristics of ssubmerged and nonsubmerged titanium implants. An experimental study in the Labrador dog.
Authors: Ericsson I. , Nilner K. , Klinge B. , Glantz P.‐O.
Published: March 2003

Using 5 Labrador dogs, certain characteristics of the peri‐implant tissues were analyzed after using a 1‐step surgical procedure for installation of Brånemark® implants. Six titanium implants, 3 in each mandibular quadrant, were installed in the regions of the right and left first molars and the fourth and third premolars. In the right mandibular quadrant, a traditional 2‐step procedure was employed, whilst in the left quadrant, a 1‐step procedure was carried out. The animals were monitored during a 6‐month period. Biopsies of the healed peri‐implant mucosa showed signs of superficial inflammation. The histological analysis revealed that i) the connective tissue lateral to the junctional epithelium showed limited accumulations of inflammatory cells (PICT), and ii) that at implant sites that had been exposed to the oral cavity for 6 months (1‐step implants), an inflammatory cell infiltrate (abutment ICT) consistently was present in the tissues facing the abutment‐fixture junction (AFJ). This infiltrate was separated from the bone crest by a 0.8mm‐wide zone of normal connective tissue. Irrespective of the surgical procedure applied, the radiographic and histometric measurements disclosed that i) the crestal bone loss was about 2.4mm, ii) the height of the peri‐implant mucosa varied from 3.5mm to 3.9mm, iii) the bone crest was located 1.1–1.5 mm apical of AFJ as well as of the apical termination of the junctional epithelium (aJE), and iv) a junctional epithelium of 2.1–2.4mm faced the implant surface. In conclusion, this study demonstrates that, using a dog model, titanium dental implants ad modum Branemark installed according to a 1‐step or to a 2‐step surgical procedure will obtain similar soft tissue adaptation and proper bone anchorage (osseointegration). Further studies are, however, required to ascertain the long‐term clinical feasibility of the 1‐step approach.
A novel model system for the study of experimental guided bone formation in humans
Authors: Hämmerle C. H. F. , Schmid J. , Olah A. J. , Lang N. P.
Published: March 2003

The aim of the present experiment was to test a novel model system, designed to obtain human specimens of regenerated and also newly generated jaw bone, for the study of the biological events under a variety of conditions. Following information and disclosure of possible risks associated with a minor oral surgical procedure, 9 systemically healthy subjects (5 men, 4 women, mean age 31.7 years) signed consent forms and volunteered to participate in this study. Hollow test cylinders with an outer diameter of 3.5mm, an inner diameter of 2.5mm, and 4mm in height were used. They were manufactured from commercially pure titanium and exhibited a highly polished inner surface and a titanium plasma sprayed outer rough surface. A mucoperiosteal flap was raised in the retromolar area of the mandible corresponding to standard retained third molar surgery. Following flap reflection a standardized hole was drilled through the cortical bone into the bone marrow using round burs. The congruent test cylinders were firmly placed into the prepared bony bed yielding primary stability. One‐and‐a‐half to 2mm of the test device were submerged below the level of the surrounding bone, while the remainder surpassed the level of the bone surface. The bone‐facing end of the cylinder was left open, while the coronal soft tissue facing end was closed by an ePTFE‐membrane. The flap was sutured to obtain primary wound closure. In order to prevent infection, penicillin was prescribed systemically and oral rinses of chlorhexidine were administered. After 2, 7, and 12 weeks one test device including the regenerated tissue was surgically harvested, while after 16, 24 and 36 weeks respectively, 2 devices were harvested and processed for soft or hard tissue histology or histochemistry. The two surgical procedures and the presence of the test cylinders during the time of healing were well tolerated by the volunteers. In all 9 subjects generated tissue could successfully be harvested. The tissue generated after 2 and 7 weeks presented with a cylindrical shape, whereas the specimens harvested at 12 weeks and thereafter resembled the form of an hourglass. Specimens of 12 weeks and less regeneration time were almost entirely comprised of soft tissue, while specimens with regeneration time of 4 months and more were composed of both soft and increasing amounts of mineralized tissue. It is concluded that the presented model system is suitable to study temporal dynamics and tissue physiology of bone re‐generation in humans with minimal risk for complications or adverse effects to the volunteers.
Influence of initial implant mobility on the integration of titanium implants. An experimental study in rabbits.
Authors: Hämmerle C. H. F. , Schmid J. , Olah A. J. , Lang N. P.
Published: March 2003

In the present study, the influence of initial instability on the healing of titanium implants was studied in 9 lop‐eared rabbits. Titanium implants (Brånemark System®) were inserted in the tibiae, a location with cortical bone only, in such a way that they were either stable (control), rotation‐mobile, or totally mobile. Implants were also inserted in the distal femoral condyles, representing an implantation bed with mainly cancellous bone, so they either showed no initial mobility (control) or were rotation‐mobile. After 12 weeks of healing, the implants were retrieved, together with surrounding bone, fixed, dehydrated, and embedded in plastic resin. About 10 μm thick ground sections were prepared for light microscopic morphometry. The mineralized bone to titanium contact, and the amount of bone occupying the threads, were calculated, whereafter the outcome of the different locations were compared. All retrieved implants were clinically stable at the end of the experiment. For the tibia sites, a statistically significant less bone to titanium contact, and a less amount of bone in the threads, were found for the totally mobile implants, as compared to the corresponding initially stable controls. Moreover, a statistically significant higher amount of bone was found in the threads of the rotation‐mobile implants inserted in the femoral condyle as compared to their initially stable controls. The study indicated that initial rotation‐mobility. independent if it occurs in cortical or trabecular bone, does not necessarily lead to an inferior integration of unloaded implants. However, initial total implant mobility within the cortical layer results in a statistically significant less amount of lb one around the implants, as compared to stable controls.
Procollagen α1(I) transcripts in cells near the interface of coralline implants in rats, detected by in situ hybridization
Authors: Reis S. A. , Voigt C. , Müller‐mai C. , Herbst H. , Bisson S. , Gross U.
Published: March 2003

Cells with procollagen α1(I) transcripts were demonstrated at the interface of natural coral mineral implanted in the femur of rats after 7, 14, 21 and 28 days by in situ hybridization with digoxigenin‐labelled RNA probes. Procollagen α1(I) transcripts were detectable in osteoblasts between 7 and 28 days after implantation. As early as 7 days after implantation, procollagen α1(I) RNA expression was also demonstrated in fibroblasts; the transcript steady state levels decreased until the 28th day, when they subsided completely. The development of bone was significant during the 4 weeks of implantation. Inhibition of bone development by the coralline material could not be recorded.
Initial attachment of human gingival fibroblast‐like cells in vitro to titanium surfaces oretreated with saliva and serum
Authors: Zöller G. O. , Zentner A.
Published: March 2003

Wound healing at the implant‐soft tissue interface occurs in the presence of saliva and blood. The aim of this in vitro study was to investigate potential influence of saliva and serum on initial attachment of human gingival fibroblast‐like cells to titanium (Ti) surfaces. 10×10mm large specimens were prepared from pure Ti, incubated for 1 h in either whole human saliva, fetal calf serum, their mixtures in proportions 75:25, 50:50 and 25:75, or buffer as control. Subsequently suspensions of human gingival fibroblast‐like cells were applied in 4 separate assays to Ti surfaces for 40 min and cell attachment was evaluated by means of image analysis under reflected light microscopy. Significantly lower numbers of attached cells (p<0.001) were found on all surfaces pretreated with saliva alone or in combination with serum. Pretreatment with serum alone showed no consistent enhancing effect on cell adhesion. These results suggest that exposure of implant necks to saliva during implant insertion or peri‐implantitis treatment might inhibit adhesion of gingival fibroblasts and thus indirectly support isolation of the implant by epithelial proliferation.