bluuebunny/crossref_metadata_2025 huggingface dataset:
Different clinical expressions in two families with Stargardt’s macular dystrophy (STGD1)
Authors: Eksandh Louise , Ekström Ulf , Abrahamson Magnus , Bauer Birgitta , Andréasson Sten
Published: March 2003

Purpose: To describe the clinical expressions, with emphasis on electrophysiological examinations, in two Swedish families with Stargardt’s macular dystrophy (STGD1).

Methods: Two pairs of siblings with STGD1, for whom diagnosis had been confirmed by genetic linkage to the ABCA4 gene region, were examined regarding visual acuity, kinetic perimetry, fundus photography, full‐field ERG and multifocal ERG (MERG). Possible disease‐causing mutations were screened for by DNA sequencing of selected regions of the ABCA4 gene.

Results: All STGD1 patients had visual acuity 0.07–0.1. The two families presented different fundus appearances, MERGs and implicit times on 30 Hz flicker white light full‐field ERGs. Genetic analysis revealed one unique sequence variation in exon 19 of the ABCA4 gene, in one allele from the patients of one of the families. This point mutation causes the amino acid substitution T972N in the ABCR protein.

Conclusion: Two pairs of siblings with STGD1 presented two different expressions of the disease regarding the distribution of the retinal dysfunction. One possible molecular explanation to the different clinical expressions may be the T972N substitution present in the ABCR protein in one of the STGD1 families investigated.
Spider keratouveitis A case report
Authors: Sandboe Frode D.
Published: March 2003

Purpose: To present a case report on a patient with keratouveitis after exposure to a tarantula.

Material: A 15‐year‐old boy presented with ocular redness and discomfort after his pet tarantula (Chilean Rose) had walked over his face.

Methods: Clinical examination revealed inflammatory reactions in the corneas and the anterior chamber. After nine months, two subepithelial infiltrates of the cornea emerged, surrounding tarantula hairs of the stroma. The hairs were removed.

Results: Topical steroids relieved the symptoms, but ten months after exposure there was still a mild reaction in the anterior chamber of the right eye.

Conclusion: Hairs from pet tarantulas might penetrate deeply into the eye and give keratouveitis. The hairs might be difficult to detect. Though rare, this phenomenon should be known by both ophthalmologists and the public.
Putative non‐uniting double central retinal artery system
Authors: Beiran Itzchak , Gelfand Yuval , Miller Benjamin
Published: March 2003

Purpose: To report a case of probable non‐uniting double retinal arterial circulation.

Methods: Case report. A 66‐year‐old man suffered central retinal artery occlusion.

Results: The medical findings and angiographic workup supported the existence of double central retinal circulation not uniting before entering the globe and independently branching in the retina.

Conclusions: In previously recognized unusual anatomic structures of the central retinal artery two parallel arteries were recognized, both of which united before entering the globe. We have described a rare anatomic variant in which those arteries remained separated after entering the globe, including while branching in the retina.
The frequency of amblyopia among visually impaired persons
Authors: Jakobsson Peter , Kvarnström Gun , Abrahamsson Mariann , Bjernbrink‐Hörnblad Eva , Sunnqvist Birgitta
Published: March 2003

Purpose: To investigate the frequency of amblyopia among visually handicapped patients.

Methods: The study is a retrospective investigation of all living patients registered in four Visual Rehabilitation Centres in a region in southern Sweden. The area's total population numbered 865,612 persons of whom 11,365 were registered as visually handicapped (with visual acuity ≤ 0.3 in the better eye).

Results: Amblyopia was the main cause of decreased visual acuity in one eye in 1.72% (195 of 11,365) of the patients. The average age of the patients with amblyopia was 69 years (9−95 years) and 28.2% of these patients were less than 65 years old (the age for retirement in Sweden).

The median visual acuity in the amblyopic eye among these patients was 0.1. The median visual acuity in the nonamblyopic eye was 0.2. The most common cause of decreased vision in the nonamblyopic eye was macular degeneration (39.5%). Bilateral amblyopia was present in 13 (6.7%) of the amblyopic patients. By comparing this study with earlier studies, we can calculate that about 1.2% of the persons with amblyopia 0.3 or lower will eventually become visually handicapped.

Conclusion: A small but considerable number of patients who attend the Visual Rehabilitation Centres have amblyopia as a cause of their visual impairment. Since amblyopia can be treated if detected in childhood, later visual rehabilitation of these patients can be avoided or delayed, thereby reducing rehabilition costs for society.
Colour contrast sensitivity in ocular hypertension. A five‐year prospective study
Authors: Friström Björn
Published: March 2003

Purpose:  To evaluate a peripheral colour contrast sensitivity test as a tool for early diagnosis of glaucoma in a five‐year prospective study.

Patients and methods
:
Peripheral colour contrast sensitivity was measured with a computer graphics system developed by Arden et al. The test colours were varied along the protan, deutan and tritan colour confusion axes on a scale from 0 to 100 percentage units. Fifty‐five ocular hypertensive (OH) patients examined with the colour contrast test, stereoscopic photography of the optic discs, and measurements of visual fields (Humphrey 24–2 glaucoma hemifield test (GHT)) in 1994, were re‐examined after five years.

Results:  Ten patients were ‘outside normal limits’ in the GHT at follow‐up. This group of 10 patients did not differ in colour contrast thresholds at the test in 1994 from the 45 who were still ‘normal’ (or ‘borderline’) at follow‐up. Neither were there proportionally more patients with GHT ‘outside normal values’ for the patients with high colour contrast thresholds (> 30% units) in 1994 regarding any of the three colour axes. As judged from patient files, 27 patients had developed glaucoma during follow‐up. Although there were differences between these 27 glaucoma patients and the remaining OH group at the colour contrast test in 1994, these differences did not reach statistical significance for any of the colour axes (largest difference in the tritan axis: 6.2% units, P = 0.0745). At follow‐up, however, there was a significant difference in colour contrast for the protan axis between the clinical glaucoma group and the OH group (6.7% units, P = 0.0105).

Conclusion
:
The method used for colour contrast measurement did not reveal glaucomatous changes before conventional perimetry (Humphrey 24–2, GHT). Neither did it predict the patients who, in our clinic, subsequently developed glaucoma during a five‐year period. A change over time in colour contrast in the protan axis for an OH patient may, however, indicate glaucoma development.
Biochemical markers of the L‐arginine‐nitric oxide pathway in the aqueous humour in glaucoma patients
Authors: Kotikoski Hanna , Moilanen Eeva , Vapaatalo Heikki , Aine Esko
Published: March 2003

Purpose:  To study the role of the L‐arginine‐nitric oxide (NO) pathway in aqueous humour dynamics by measuring nitrate, nitrite and cyclic (cGMP) levels in guanosine 3′,5′‐monophosphate the aqueous humour of glaucomatous and nonglaucomatous cataract patients.

Methods:  The study involved 38 glaucoma patients undergoing unilateral cataract surgery in the glaucomatous eye and 38 cataract control patients matched for sex, age, smoking habits and organic nitrate medication. All subjects underwent ophthalmic examination, and blood pressure was measured preoperatively. Nitrite, nitrate and cGMP levels were measured in aqueous humour and serum.

Results:  The NOx (nitrite + nitrate), nitrite and cGMP concentrations in the aqueous humour were slightly higher in the glaucoma patients than in the control patients, but the differences did not reach statistical significance. The levels of cGMP in serum were higher in the glaucoma patients (P = 0.053). The subgroup of glaucoma patients with pseudoexfoliation had lower NOx and nitrite values in the aqueous humour (P = 0.046 and P = 0.345, respectively) than the matched controls, while cGMP levels were higher (P = 0.043). Levels of NOx and nitrite in the aqueous humour were higher in patients using oral nitroglycerin (P = 0.062 and P = 0.042, respectively) than in patients without this medication. Blood pressure was higher in the glaucoma patients, with a mean of 165/89 mmHg as compared to 153/81 mmHg in the controls (P‐values 0.071/0.008).

Conclusions:  No differences in NO metabolites were found between glaucoma and control patients. However, any real changes may have been disguised by optimal medication of glaucoma. Low NOx and high cGMP levels in the aqueous humour of pseudoexfoliation patients warrant further evaluation in a larger study.
Long‐term visual outcomes in the Cataract‐Free Zone Project in Brazil
Authors: De Senne Firmani M. B. , Cardillo José A. , Rocha Eduardo M. , Kara‐José Newton
Published: March 2003

Purpose:  To determine the long‐term visual outcomes and causes of poor vision in the cataract population in Brazil treated in the Cataract‐Free Zone Project.

Methods:  Project A subjects (62 patients) were recruited in Taquaritinga, SP, 26 months after surgery. Project B subjects (34 patients) were recruited in São João da Boa Vista, SP, 43 months after surgery. All patients underwent visual screening and eye examination (examination 1). They were classified according to visual acuity in the operated eye and the causes of poor vision were diagnosed and referred for treatment. The results of these interventions were collected (examination 2) and analysed by Chi‐square test.

Results:  At examination 1 in project A, 47 of 62 patients (75.6%) had visual acuity ≤ 20/100. The main causes of poor vision were refractive error (31.9%) and posterior capsule opacification (17.0%), with or without refractive error. At examination 1 in project B, 22 of 34 patients (64.7%) had visual acuity ≤ 20/100. The main causes of poor vision were again posterior capsule opacification (50.0%) and refractive error (9.0%). After posterior capsulotomy with Nd:YAG laser and prescription of new corrective eyeglasses, visual acuity = 20/80 was obtained in 64.5% of patients in project A (OR = 0.18, CI = 0.07–0.41) and 70.5% of patients in project B (OR = 0.19, CI = 0.06–0.60) at examination 2. The causes of blindness in the remaining patients were identified.

Conclusion:  This type of project is effective in reducing blindness caused by cataracts in developing countries. However, long‐term scheduled follow‐up of operated patients is an effective means of avoiding consecutive blindness resulting from secondary cataracts and refractive changes.
A prospective study of children treated for retinoblastoma: Cognitive and visual outcomes in relation to treatment
Authors: Ek Ulla , Seregard Stefan , Jacobson Lena , Oskar Kristi , Af Trampe Eva , Kock Erik
Published: March 2003

Purpose : To assess cognitive and visual outcomes in children treated for retinoblastoma.

Patients and Methods:  A population‐based group of 22 children treated for retinoblastoma were followed in a longitudinal, prospective study. Eleven children had unilateral tumours, all of which had been enucleated. The remaining 11 had bilateral tumours. Seven of these had undergone unilateral enucleation and local or external beam radiation to the other eye. Four children had been treated with local or external beam radiation only. Cognitive outcome and visual function was assessed at 4 and 6 years of age.

Results:  We found no general delay in cognitive or motor development at 4 or 6 years of age. Better cognitive capacities were found in the bilateral/irradiated retinoblastoma patients than in unilateral/non‐irradiated patients. However, two of the irradiated children, both of whom had been treated at 1 month of age, performed below group mean. None of the children was totally blind. Three children were visually impaired due to tumours affecting the macular area in the remaining eye; another three had subnormal visual acuity but no macular pathology. A total of 14 children had been enucleated and had normal vision in the remaining eye. Visual fields and dark adaptation were adversely affected in a few cases, but colour vision was normal in all.

Conclusion:  Bilateral retinoblastoma seems to be associated with superior cognitive capacities. Few children were visually impaired according to WHO criteria. We speculate that children treated during the first months of life may be at risk of adverse cognitive and visual outcomes. The immature brain may be affected by radiation treatment, causing both cognitive and visual deviations.
A small number of older type 2 diabetic patients end up visually impaired despite regular photographic screening and laser treatment for diabetic retinopathy
Authors: Hansson‐Lundblad Catharina , Holm Kristina , Agardh Carl‐David , Agardh Elisabet
Published: March 2003

Purpose: The present study describes the prevalence of visual impairment and blindness in a geographically defined population 8 years after the introduction of a screening programme in 1987 for early detection of sight‐threatening diabetic retinopathy.

Methods: Of 374 patients with diabetes, comprising 2.6% of the population in the study community, 72% were examined with fundus photography or biomicroscopy during 1994–95. These patients form the basis of this study. The screening programme was fulfilled by 93% of subjects, all of whom underwent ophthalmic examinations at least every other year. A total of 79 eyes in 52 patients received photocoagulation for macular oedema alone or in combination with severe non‐proliferative or proliferative retinopathy.

Results: Eight years after the implementation of the programme, only three patients, all with type 2 diabetes (diabetes diagnosed at or after 30 years of age), had visual acuity ≤ 0.1. The total number of eyes with visual acuity ≤ 0.5 was higher in insulin‐treated type 2 diabetic patients (n = 20) than in those on oral treatment (n = 5) or diet treatment only (n = 1) (p = 0.006 in both cases). The only independent risk factor for visual impairment in eyes with sight‐threatening retinopathy was age.

Conclusion: A small number of older type 2 diabetic patients end up with visual impairment due to unsuccessful photocoagulation of macular oedema.
The capillary blood flow in ischaemic type central retinal vein occlusion: the effect of laser photocoagulation
Authors: Arvas Sema , Ocakoglu Ozcan , Ozkan Sehirbay
Published: March 2003

Purpose:  To determine the effect of photocoagulation on retinal blood flow (RBF) in eyes with ischaemic type central retinal vein occlusion (CRVO).

Patients and Methods:  Retinal blood flow was measured in 12 eyes with CRVO, 12 fellow eyes and 12 eyes of 12 age‐matched healthy subjects using the Heidelberg retinal flowmeter (HRF). Microvascular blood flow values (volume, flow, velocity) were recorded from the upper temporal retina and macula. Eyes were re‐examined 1 month after photocoagulation. We investigated whether there was a difference in RBF measurements before and after photocoagulation treatment.

Results:  In eyes with CRVO, mean RBF values (volume, flow and velocity) obtained from the upper temporal retina increased significantly after treatment (paired t‐test, p < 0.05). In contrast, mean RBF values from the macula were unaffected by photocoagulation (paired t‐test, p > 0.05). Retinal blood flow values from the upper temporal retina obtained from control subjects were significantly higher than the values in eyes with CRVO before and after photocoagulation (unpaired t‐test, p < 0.05), but there was no significant difference between control subjects and CRVO patients in RBF values from the macula (unpaired t‐test, p > 0.05). Mean RBF values were significantly higher in CRVO patients' fellow‐eyes before photocoagulation in the eyes with CRVO (paired t‐test, p < 0.05) but were lower than in age‐matched healthy control eyes (unpaired t‐test, p < 0.05). Macular blood flow did not differ between the eyes with CRVO and fellow eyes (paired t‐test, p > 0.05).

Conclusion:  Laser photocoagulation increased retinal blood flow in eyes with CRVO, but RBF did not reach normal values. Photocoagulation was found to have no effect on RBF in the macular area.
Herpes simplex virus type 1 encephalitis associated with acute retinal necrosis syndrome in an immunocompetent patient
Authors: Gain Philippe , Chiquet Christophe , Thuret Gilles , Drouet Emmanuel , Antoine Jean‐Christophe
Published: March 2003

Purpose:  The onset of acute retinal necrosis secondary to herpes simplex encephalitis is exceptional. We report such an association in an immunocompetent patient, in whom the genome of herpes simplex virus type 1 (HSV‐1) was identified successively at both sites of infection.

Methods:  Polymerase chain reaction (PCR) assay of HSV‐1 in cerebrospinal fluid (CSF) and aqueous humour.

Results:  An immunocompetent patient aged 40 years presented with HSV‐1 encephalitis, which was confirmed by imaging, viral serology and identification of the HSV‐1 genome in the CSF. The subject's immunological profile was normal. The patient was treated with foscavir. Six weeks after clinical recovery and negative PCR, the patient presented with a unilateral acute retinal necrosis syndrome. Polymerase chain reaction of the aqueous humour was positive, while serology and PCR of the CSF remained negative.

Conclusion:  Identification of the HSV‐1 genome at the two successive sites of infection stresses the possibility of brain‐to‐eye transmission of HSV‐1.
Preschool vision screening in a Swedish city region: results after alteration of criteria for referral to eye clinics
Authors: Hård Anna‐Lena , Sjödell Lena , Borres Magnus P. , Zetterberg Ingrid , Sjöstrand Johan
Published: March 2003

Purpose:  To investigate the results of preschool vision screening and to evaluate new referral criteria in a Swedish city region. Prior to 1992, all children with visual acuity (VA) of less than 0.8 at the age of 4 years were referred to an eye clinic. Since 1992, those with slightly reduced VA (0.65 in each eye or 0.65 in one eye and 0.8 in the other) have been retested at 5.5 years of age and referred if their VA is less than 0.8.

Methods:  In a prospective study, the results of vision testing were collected for all children (n = 483) born in 1989–92 inclusive and registered at one child health centre at 4 years of age. The study also involved 123 other children scheduled for retesting at the age of 5.5 years. The results of the examinations and treatments at the eye clinic are evaluated.

Results:  Few of the children with slightly reduced VA who were retested at the age of 5.5 years had visual defects that required treatment. In those who were treated, the results of treatment were good.

Conclusions:  The new screening criteria appear to be appropriate and are recommended.
Chlamydia pneumoniae in central retinal artery occlusion
Authors: Vécsei Pia V. , Kircher Karl , Reitner Andreas , Khanakah Gelas , Stanek Gerold
Published: March 2003

Purpose:  There is increasing evidence that the common respiratory human pathogen Chlamydia pneumoniae has a causative role in atherosclerosis. We investigated the association of this pathogen with acute central retinal artery occlusion (CRAO).

Patients and Methods:  Sera of 14 consecutive patients with CRAO and of 14 age‐ and sex‐matched control subjects were examined. Antibodies against chlamydial lipopolysaccharide (LPS) and outer membrane proteins of C. pneumoniae were determined by an enzyme‐linked immunosorbent assay (ELISA).

Results:  In the CRAO group, seven patients (50%) were found to be IgA positive, 12 (86%) were IgG positive and one (7%) was IgM positive for chlamydial LPS antibodies. In the control group 36%, 79% and 14% were IgA, IgG and IgM positive, respectively. The results showed no significant difference between the groups. In the CRAO group, IgA, IgG and IgM antibodies to C. pneumoniae were found in 43%, 79% and 0% of subjects, respectively. These findings did not differ significantly from those pertaining to matched controls.

Conclusions:  These data do not support an association between acute CRAO and current C. pneumoniae infection.
Influence of the prion protein gene, Prnp, on scrapie susceptibility in sheep
Authors: Tranulis Michael A.
Published: March 2003

Natural scrapie in sheep occurs through a complex interplay between host genetic elements and various strains of the infectious scrapie agent. Scrapie‐related polymorphisms in the coding region of the prion protein (PrP) gene, Prnp, have been studied in a number of breeds. The disease‐promoting V136 allele, and the susceptibility‐reducing R171 allele, have proved to be most important. However, variation in the coding region of Prnp cannot alone explain the diverse patterns of scrapie susceptibility in various breeds. For instance, in many breeds plagued with scrapie, the V136 allele appears to be a rarity. The R171 allele greatly reduces scrapie susceptibility. This lays the molecular foundation for marker‐assisted breeding for reduced scrapie susceptibility now underway in many countries. Although potentially important, and still under investigation, variable expression level and pattern of the ovine Prnp appears to be of little importance for the occurrence of natural scrapie. Studies of scrapie in mice also indicate that genetic elements other than Prnp may have a strong influence on scrapie incubation time, and hence susceptibility. Narrowing down the search to focus on these elements and identification of candidate genes are important tasks for future research in sheep scrapie.
Classification, identification and subtyping of bacteria based on pyrosequencing and signature matching of 16S rDNA fragments
Authors: Jonasson Jon , Olofsson Margaretha , Monstein Hans‐Jürg
Published: March 2003

The rapid identification of the etiological agent of microbial infections can bring about both clinical and financial benefits. Thus, fast and generally applicable classification methods are needed that will enable us to rapidly distinguish pathogenic bacteria from commensals or saprophytic bacteria found in the same habitat. We here show that provisional classification of bacterial isolates can be performed on a large scale based on 16S rRNA sequence comparisons using PyrosequencingTM, a recently described real‐time DNA sequence analysis technique, and the concept of signature matching. The probes we have developed, together with the new technology, will enable early diagnosis of specific pathogens, which is critical for the rational use of antimicrobial therapy in clinical medicine.
Bismuth‐induced lysosomal rupture in J774 cells
Authors: Stoltenberg M. , Larsen A. , Zhao M. , Danscher G. , Brunk U. T.
Published: March 2003

Bismuth‐containing drugs have several applications, one being their use against Helicobacter pylori‐associated peptic ulcers, and bismuth has been discovered in macrophages at the base and margins of peptic ulcers. In the present study, the autometallographic technique for the histochemical demonstration of bismuth was applied, showing that bismuth citrate‐exposed J774 cells accumulate the metal in their lysosomes. Such accumulations resulted in lysosomal rupture – assayed by the acridine orange uptake technique and flow cytofluorometry – and ensuing apoptotic cell death.
Soluble membrane‐type 1 matrix metalloproteinase (MT1‐MMP) and gelatinase A (MMP‐2) in induced sputum and bronchoalveolar lavage fluid of human bronchial asthma and bronchiectasis
Authors: MAISI PÄIVI , PRIKK KAIU , SEPPER RUTH , PIRILÄ EMMA , SALO TUULA , HIETANEN JARKKO , SORSA TIMO
Published: March 2003

The aim of this study was to investigate the involvement of the MT1‐MMP/MMP‐2 cascade in induced sputum (IS) and bronchoalveolar lavage fluid (BALF) from bronchial asthma (BA) and bronchiectasis (BE) patients and healthy controls. The molecular forms and cellular origins of MT1‐MMP and MMP‐2 were determined by Western immunoblotting, immunohistochemistry and in situ hybridization. Elevated levels of soluble activated and autocatalyzed MT1‐MMP species as well as activated forms of MMP‐2 in IS and BALF samples from BA and BE patients were evidenced. The activation degrees of soluble MT1‐MMP and MMP‐2 were significantly correlated in BA and BE IS and BALF. Only low levels of both these MMPs were observed in healthy control IS and BALF. The co‐expression of MMP‐2 with MT1‐MMP was evidenced by double immunostaining in bronchial epithelial cells, submucosal glandular cells, smooth muscle cells and monocyte/macrophages. The MT1‐MMP/MMP‐2 cascade is present and active in human inflammatory lung disease fluid and tissue samples. This cascade seemingly reflects the active destructive phases of these chronic lung diseases.
Structure of the bone‐titanium interface in retrieved clinical oral implants
Authors: Sennerby L. , Ericson L. E. , Thomsen P. , Lekholm U. , Åstrand P.
Published: March 2003

7 clinically stable, “osseointegrated”, titanium implants, inserted in human jaws for l–16 years, were retrieved for morphological analysis of the bone‐titanium interface, using 3 different preparation techniques. The bone‐titanium interface varied as judged from light microscopy of ground sections. The threads of the implants were well filled 79–95% with dense lamellar bone as quantified with morphometry. A large fraction of the implant surface (56–85%) appeared to be in direct contact with the mineralized bone. In general, the non‐boric areas consisted of pockets with osteocytes, bone marrow tissue and/or vessels. Sections were prepared for light microscopy and transmission electron microscopy using a fracture technique. where the implant was separated from the embedded tissue before sectioning, and an electropolishing technique, where the bulk part of the implant was electrochemically removed. In areas judged as direct mineralized bone‐titanium contact in the light microscope. the interfacial structure varied at the ultrastructural level. In areas along the interface, unmineralized tissue was present either as a narrow 0.5–l μm wide zone containing collagen fibril or as deeper pockets containing osteocytes or vessels. In areas with mineralized bone contact. an amorphous granular layer (100–400 nm wide) with no mineral was observed in the innermost interface bordering the mineralized bone, with an electron‐dense lamina limitans‐like line (approximately 50 nm thick). It is concluded that the bone‐titanium interface of the 7 clinically retrieved titanium oral implants examined in the present study bone was heterogenous. In areas of a direct mineralized bone‐titanium contact at the ultrastructural level. mineralized bone reached close to the implant surface, but was separated by an amorphous layer. 1 being 100–400 nm thick.
Guided tissue regeneration ensures osseointegration of dental implants placed into extraction sockets. An experimental study in monkeys.
Authors: Warrer K. , Gotfredsen K. , Hjsrting‐hansen E. , Karring T.
Published: March 2003

The aim of the present study was to explore the possibility of achieving osseointegration of dental titanium implants, inserted into alveoli immediately after tooth extraction, by covering the recipient site with a teflon membrane. In each of 7 monkeys, mucoperiosteal flaps were raised on the buccal and palatal aspects of the maxillary molars in both sides of the jaw. The second molars were then extracted and self tapping titanium implants of the screw type (Astra® Dental Implants) were inserted into the sockets of the largest roots. In the coronal portion of the sockets, a void was always present between the implant and the socket walls. In one side of the jaw, a membrane (Gore‐;Tex Aug‐mentation Material@) was adjusted to cover the implant. The implant in the other side of the jaw served as control and was only covered by the tissue flaps. Microscopic analysis after 3 months of healing revealed that soft tissue was facing the coronal portion of the implants to a varying degree in the control side, while osseointegration was consistently observed to the top of the membrane‐covered implants which remained submerged throughout the experimental period. The results suggest that the membrane techniaue can secure complete osseointegration of implants inserted immediately into extraction sockets.
Soft tissue reaction to de novo plaque formation on implants and teeth. An experimental study in the dog
Authors: Berglundh T. , Lindhe J. , Marinell C. , Ericsson I. , Liljenberg B.
Published: March 2003

The aim of the present investigation was to assess the effect of de novo plaque formation on the gingiva and masticatory mucosa around teeth and implants. The study was performed in 5 beagle dogs which at the initiation of the experiment were 15 months old. During a preparatory period, the mandibular right premolars were extracted, 3 fixtures installed, abutment connection performed and a 4‐month period of plaque control completed. A clinical examination was performed and biopsies of the second mandibular premolar (Pz) and the contralateral implant site (2P) were sampled. The dogs were allowed to form plaque during a period of 3 weeks. The clinical examination was repeated and biopsies harvested from the 2 remaining implants and the contralateral tooth sites. The tissue samples were prepared for histometric and morphometric analysis. Both the masticatory mucosa at implants and the gingiva responded to de novo plaque formation with the development of an inflammatory lesion. The size as well as the composition of the lesions in the 2 tissues had many features in common. It was concluded that the mucosa around implants and the gingiva around teeth had a similar potential to respond to early plaque formation.
Long‐standing plaque and gingivitis at implants and teeth in the dog
Authors: Ericsson I. , Berglundh T. , Marinello C. , Liljenberg B. , Lindhe J.
Published: March 2003

The experiment was performed to evaluate the effects of long‐standing plaque on the gingiva and peri‐implant mucosa. 5 beagle dogs were used in the study. The mandibular right premolars were extracted. 3 months later, 3 titanium fixtures were installed and after another 3 months, abutment connection was performed. Plaque control, in the implant as well as the contralateral tooth regions, was maintained during a 4‐month period prior to the start of the main experiment. On Day 0, the teeth and implant sections were examined with respect to plaque and gingivitis. The plaque control program was terminated. The animals were subsequently fed a diet which allowed gross plaque accumulation. After 90 days of undisturbed plaque formation, the dogs were re‐examined and biopsies harvested from implants and contralateral teeth. On day 90, all teeth and implants had accumulated large amounts of plaque. The soft tissue at implants and teeth bled on gentle probing. The histological examination of the gingiva and the peri‐implant mucosa revealed:(i) both tissues contained an inflammatory cell infiltrate; ICT, (ii) the apical extension of ICT was more pronounced in the peri‐implant mucosa than in the gingiva and (iii) the composition of the 2 lesions had many features in common.
Healing‐in of root analogue titanium implants placed in extraction sockets. An experimental study in the beagle dog.
Authors: Lundgren D. , Rylander H. , Anderssong M. , Johansson C. , Albrektsson T.
Published: March 2003

The aim of these animal experiments was to characterize and evaluate the healing‐in of root analogue titanium implants fitting with high precision to the alveolar wall. Four beagle dogs were used in the study. The roots of the 3rd and 4th mandibular premolars in both quadrants of 3 dogs and in 1 quadrant of 1 dog (dog 4) were extracted after hemisection. Each root was machine‐copied to 1 titanium analogue. In dog 4, however, 2 titanium analogues were fabricated from each of the 4 extracted roots. This enabled insertion of analogues also into the contralateral sockets obtained by extraction of the corresponding roots immediately before implant installation, which was undertaken 2 weeks after the first extractions. Thus, in all, 32 analogues were implanted in their respective (or contralateral) sockets following ridge incision and elevation of mucoperiosteal flaps. The analogues were carefully covered by the repositioned flaps. In dog 4, 2 analogues from the immediate sockets and 2 from the 2‐week sockets were surgically exposed and supplied with titanium crowns after a healing period of 2 months. The healing after implantation was evaluated by clinical, radiographic and histological measures after 2, 12 or 36 months. Two analogues (6%) were lost due to early (during the 1st week) exposure to the oral cavity. Another 2 analogues (6%) were, although not exposed, encapsulated by soft tissue and were easily removed with a surgical forceps. Twenty‐eight analogues (88%) were healed‐in by contact between bone and implant (osseointegration). The mean percentages of bone tissue in contact with the implant of such analogues were 30.5% after 2 months, 64.8% after 12 months and 68.1% after 36 months, as evaluated by histomorphometric analysis. The 4 analogues supplied with titanium crowns carried those with maintained bone anchorage throughout an experimental period of 36 months. The character of the interface between the analogue and the surrounding bone tissue was the same regardless of whether the implantation was performed immediately 1 or 2 weeks after extraction of the roots.
Microbial colonization on natural tooth structure compared with smooth and plasma‐sprayed dental implant surfaces
Authors: Gatewood R. R. , Cobb C. M. , Killoy W. J.
Published: March 2003

The purpose of this study was to characterize and compare by scanning electron microscopy (SEM) the maturation of supragingival microbial plaque on enamel and smooth titanium and that of subgingival plaque on cementum, plasma‐sprayed titanium and hydroxyapatite surfaces. Specimens (6.5 x 2 x 1 mm) were obtained from titanium implants with smooth transmucosal collars and plasma‐sprayed endosseous posts of titanium or hydroxyapatite. Unerupted third molars were sectioned to similar dimensions that included equal lengths of enamel and root surface. Ten patients with post‐treatment pocket depths of > 6 mm on 3 non‐adjacent teeth were selected and each had 1 set of the 3 specimen types bonded by random assignment to the selected teeth. Specimens were positioned so that enamel and/or smooth titanium surfaces were supra‐gingival and cementum and titanium or hydroxyapatite plasma‐sprayed surfaces were subgingival. Patients were instructed to stop oral hygiene, after which 2 specimen sets were removed at 1, 3, 5, 7 and 10 days. Two specimens of each type were examined by SEM at each time interval for supra‐ and subgingival plaque. The sequence of appearance of various microbial morphotypes in supra‐ and subgingival plaque was similar regardless of surface. In both supra‐ and subgingival plaque, depending on time interval, cocci, rods of various lengths, filamentous organisms, fusiforms, spirochetes and corn‐cob formations were observed. Mineralized plaque was noted on most subgingival specimens by day 10. These observations indicate that surface of natural teeth, smooth titanium and plasma‐sprayed titanium and hydroxyapatite support the maturation of microbial plaque with the successive inclusion of a variety of morphotypes.
On clinical loading of osseointegrated implants. A methodological and clinical study.
Authors: Glantz P.‐O. , Rangert B. , Svensson A. , Stafford G. D. , Arnvidarson B. , Randow K. , Lindén U. , Hultén J.
Published: March 2003

Strain gauges were used to record in viva and in vitro functional deformations in a fixed prosthetic appliance supported and retained by osseointegrated titanium implants. Four linear gauges were attached to each of totally 5 implant abutment cylinders and gauge signals were transferred into a computer via a digital converter. A computer program (ASYST) was used for collection, calibration and analysis of data obtained. Based on the results of a series of explorative in vitro tests, in viva experiments were performed at maximum biting as well as during chewing on certain normally available food items. The results show fundamental differences between in vitro and in vivo testing conditions. Unexpectedly high bending of the implants was recorded in many of the in viva loading situations.
Glycosaminoglycans in peri‐implant sulcus fluid from implants supporting fixed or removable prostheses
Authors: Smedberg J.‐I. , Beck C. B. , Embery G.
Published: March 2003

Previous studies have indicated that examination of glycosaminoglycans (GAG) present in peri‐implant sulcus fluid (PISF) may be a useful indicator of metabolic activity of the supporting bone. The GAG content in PISF from osseointegrated implants ad modum Bråemark in the maxilla was quantified and analysed. The study comprised 2 groups with 10 patients in each group. In one group the patients wore removable prostheses; in group 2 the patients wore fixed prostheses. The groups were matched for age, sex and function period of their prosthetic appliances. Clinical data were recorded, and the levels of the GAG hyaluronan (HA) and chondroitin‐4‐sulphate (C4S) were assessed using cellulose acetate electrophoresis and densitometric scanning of Alcian blue‐stained strips against known GAG standards. PISF volumes and levels of C4S as potential bone marker showed no significant difference both groups median 0.003 μg). There was a somewhat higher median value for HA (0.015 μg) in the group of patients with removable prostheses compared with the group with fixed prosthesis =0.008 μg)(NS). HA is known to be present in high amounts in gingival tissue. As both plaque index and gingival bleeding were more frequent in patients with removable prostheses, this may be the reason for the somewhat higher value for HA in this group of patients. The difference in biomechanical properties of fixed and removable prostheses on implants do not appear to be reflected in the bone responses as measured by GAG content in PISF.
Implant treatment in resorbed edentulous upper jaws
Authors: Jemt T.
Published: March 2003

Patients with resorbed edentulous upper jaws were arranged into 2 different groups, based on an overall assessment of bone resorption prior to implant surgery. Each group comprised 3.5 patients, all of whom received an overdenture after abutment connection. The patients in the group with the best bone situation were scheduled to receive a fixed prosthesis after 1 year provided that the clinical situation was stable. The overall cumulative implant and prosthesis treatment success rates were 77% and 85%, respectively, for a 3‐year follow‐up period. Nineteen of the patients in the best bone group received a fixed prosthesis after they had used the overdenture for 1 year. These patients exhibited a cumulative implant success rate of 97%. None of the fixed prostheses was lost. Implant failures and other clinical adjustments were frequent for the first year of follow‐up, but the number of problems diminished in the subsequent years.
Osseointegration of Brånemark fixtures using a single‐step operating technique. A preliminary prospective one‐year study in the edentulous mandible.
Authors: Bernard J.‐P. , Belser U. C. , Martinet J.‐P. , Borgis S. A.
Published: March 2003

The aim of the present prospective clinical study was to analyze the feasibility of inserting Brånemark fixtures according to a one‐stage procedure including transmucosal healing and to subsequently evaluate the predictability of osseointegration as well as the potential of such implants for stabilizing complete overdentures in the edentulous mandible. Five patients (2 women, 3 men), completely edentulous in the mandible and with a mean age of 60 years, volunteered for this study. Two fixtures of various length Lpar;10–20 mm) and 3.75 mm in diameter were inserted in the lower canine regions. A standard surgical procedure including a mid‐crestal incision was used. After the placement of the fixtures, healing abutments, which are normally used during second‐stage surgery, were inserted instead of the usual cover screws. Three months after implant placement a clinical and radiographic examination was performed to confirm the presence or absence of osseointegration of the fixtures prior to exchanging the healing abutments with the spherical attachments. Finally, different clinical (Plaque Index, Bleeding Index, probing depth, Periotest® mobility) and radiographic (bone loss, peri‐implant radiolucency) parameters were recorded 9 months after loading of the fixtures by means of a complete mandibular overdenture, retained by two ball attachments in the canine regions. All fixtures were perfectly stable (mean Periotest values of −2) and presented favorable peri‐implant soft tissue conditions, and no patient was complaining about any particular symptom. As far as retention and stability of their implant supported overdenture was concerned, the participants without exception considered the therapeutic result as being perfectly adequate. The evaluation of the radiographic analysis showed a similar initial bone loss rate as reported in the literature for a submerged surgical procedure. Therefore, within the specific limits of this study. it may be concluded that Brånemark fixtures can be inserted using a single‐step surgical protocol predictably leading to successful osseointegration and subsequently provide similar peri‐implant results as reported for the traditional two stage technique. However, a longer period of observation as well as a more significant number of cases will be necessary to confirm these promising preliminary data.
Accuracy of implant‐supported prostheses in the edentulous jaw. Analysis of precision of fit between cast gold‐alloy frameworks and master casts by means of a three‐dimensional photogrammetric technique.
Authors: Jemt T. , Lie A.
Published: March 2003

Distortions of 15 routine implant‐supported prostheses were measured in relation to the master casts after completion by means of a 3‐dimensional (3‐D) photogrammetric technique. All prostheses were designed as one‐piece gold‐alloy castings with resin teeth. Five of the prostheses were placed in the edentulous maxilla, and the remaining were placed in the lower jaw. Distortion of the cylinders was mostly observed in the horizontal plane (x‐and y‐axis) while the vertical aspect seemed to be more stable. The mean 3‐D center point distortion was 42 (SD 15) and 74 (SD 38)μm for the upper and lower jaws, respectively. The measurements revealed a range of3‐D center point distortion from 16 to 80 and 15 to 165 μm for the different jaws, respectively. The corresponding 3‐D mean angular distortion of the cylinders was 51 (SD 35)μm in lower and 70 (SD 75)μm in the upper jaws. A correlation was found between 3‐D center point distortion and the width as well as the curvature of the implant arch, indicating more displacement the wider and the more curved the arch was. The 3‐D center point distortion was also significantly higher in the upper jaws which could possibly be explained by the curvature of the implant arch and higher numbers of implants in the upper jaws. Further problems with the fit of upper jaw castings could be related to more alloy in the 1 castings and poor alignment of implants.
The effect of periodontal parameters on the subgingival microbiota around implants
Authors: Papaioannou W. , Quirynen M. , Nys M. , Van Steenberghe D.
Published: March 2003

The study aimed to examine the relationship between the subgingival flora around implants and their periodontal parameters. Plaque samples from 561 implants (297 patients) were analyzed by means of differential phase contrast microscopy and compared with the sample site's probing depth. bleeding tendency on probing, and plaque and gingivitis indices. If possible, one implant with deep and one with shallow pockets were selected within the same patient. The impact of the intraoral exposure time on the microbial composition around the implants was examined cross‐sectionally, with the same group of patients. Only tendencies can be detected by the latter, and no concrete conclusions can be drawn. From the clinical parameters, increased probing depth was found to detrimentally increase the proportion of spirochetes and motile organisms, whereas the other parameters were found to be of minor importance. For partially edentulous patients only, there was a tendency for increased proportions of spirochetes and motile organisms the longer the intraoral exposure time. These observations emphasize the importance of the periodontal health of the remaining teeth (as a reservoir of pathogenic micro organisms) in partial edentulous patients rehabilitated by means of implants and indicate the importance of shallow pockets around imnlants (flan trimming when aesthetics and phonetics allow).
Identification of bone quality in conjunction with insertion of titanium implants. A pilot study in jaw autopsy specimens.
Authors: Friberg B. , Sennerby L. , Roos J. , Lekholm U.
Published: March 2003

Ten autopsy jaw specimens (6 mandibles. 4 maxillae) were used for cutting resistance measurements during low‐speed threading. Overall, 31 sites were analyzed where implants were inserted into threaded canals. Bone area measurements were performed around the implants as described previously. The cutting resistance values together with the total bone area values were found to be higher in mandibles than in maxillae, and a tendency towards higher values was seen in incisor regions compared with premolar regions. Furthermore, an intraindividual comparison between the true cutting resistance and the bone density values of prepared sites showed a statistically significant correlation. The method with cutting resistance measurements for evaluation of bone quality seems therefore to be reliable, at least when used in human autopsy jaw bone specimens.
Accuracy and precision in the radiographic diagnosis of clinical instability in Brånemark dental implants
Authors: Sundén S. , Gröndahl K. , Gröndahl H.‐G.
Published: March 2003

The aim was to evaluate accuracy and precision in the radiographic diagnosis of clinical instability in Brånemark dental implants. In two clinics specialized in the Branemark osseointegration technique we identified all patients in whom lack of clinical stability of one or more fixtures had been observed during a 5‐year period. Radiographs of these fixtures (n=62) were mixed with radiographs of clinically stable fixtures (n=158). Eight observers were asked to determine whether or not a perifixtural radiolucency was seen by means of a 5‐point rating scale expressing the confidence with which the presence or absence of a radiolucency was determined. Receiver operator characteristic analysis was used to calculate the A, values and the variability in A, values between and within observers was determined. In addition, we evaluated the agreement in rating codes within observers between repeat examinations. The A, values (mean=0.844 at the first reading and 0.856 at the second) indicated that the accuracy in radiographic diagnosis of clinical fixture instability was as least as good as that associated with other radiographic tasks such as approximal caries diagnosis and diagnosis of small periodontal bone lesions. Interobserver variability was larger than intraobserver variability. Intraobserver agreement in rating codes was relatively high and less than an average of 6% of all ratings differed with two rating codes or more. Despite the relatively good diagnostic accuracy, the probability of predicting clinical fixture instability from a radiographic examination can be low in populations with a low prevalence of fixtures showing clinical instability.