bluuebunny/crossref_metadata_2025 huggingface dataset:
Female secondary coloration in the Mexican boulder spiny lizard is associated with nematode load
Authors: Calisi R. M. , Malone J. H. , Hews D. K.
Published: September 2008

Male secondary sexual traits purportedly facilitate female choice of a potential mate's quality. One example of male quality is the ability to resist detrimental infections by parasites; sexual traits that reflect parasite infection can allow females to select for parasite resistance in future offspring. High parasite numbers can constrain the exaggeration of male traits, but few studies have examined the effects of parasites on female secondary traits. Female Mexican boulder spiny lizards Sceloporus pyrocephalus, undergo a change in secondary sexual coloration over their breeding season and express red gular regions and gray gular stripes in association with late stages of follicle maturation during the reproductive cycle, as well as blue ventral stripes. We examined if color change associated with the female reproductive cycle varied in hue, saturation and brightness in relation to high nematode loads. Our results suggest that high nematode loads of particular areas of the body are correlated with dull, as opposed to bright, secondary sexual coloration in females of S. pyrocephalus. One reason females could be most vulnerable to nematodes during late reproductive stages is because of corresponding high concentrations of circulating testosterone known to occur in this species at this time. Testosterone has demonstrated immunosuppressive effects in many species; however, results have varied and conclusive evidence for its role in immune function remains controversial. Using a subset of individuals from this study, we found that high concentrations of plasma testosterone were significantly related to high nematode loads. These findings prompt further studies examining the physiological attributes of parasite infestation, the honest signaling capabilities of nematode loads and their potential role in sexual selection for coloration in females.
Neurite outgrowth is enhanced by laminin‐mediated down‐regulation of the low affinity neurotrophin receptor, p75NTR
Authors: Rankin Sherri L. , Guy Clifford S. , Mearow Karen M.
Published: September 2008

Laminin (LN), an extracellular matrix component, is a key factor in promoting axonal regeneration, coordinately regulating growth in conjunction with trophic signals provided by the neurotrophins, including nerve growth factor (NGF). This study investigated potential interactions between the LN and NGF‐mediated signaling pathways in PC12 cells and primary neurons. Neurite outgrowth stimulated by NGF was enhanced on a LN substrate. Western blot analysis of pertinent signal transduction components revealed both enhanced phosphorylation of early signaling intermediates upon co‐stimulation, and a LN‐induced down‐regulation of p75NTR which could be prevented by the addition of integrin inhibitory arginine‐glycine‐aspartate (RGD) peptides. This p75NTR down‐regulation was associated with a LN‐mediated up‐regulation of PTEN and resulted in a decrease in Rho activity. Studies using over‐expression or siRNA‐mediated knock‐down of PTEN demonstrate a consistent inverse relationship with p75NTR, and the over‐expression of p75NTR impaired neurite outgrowth on a LN substrate, as well as resulting in sustained activation of Rho which is inhibitory to neurite outgrowth. p75NTR is documented for its role in the transduction of inhibitory myelin‐derived signals, and our results point to extracellular matrix regulation of p75NTR as a potential mechanism to ameliorate inhibitory signaling leading to optimized neurite outgrowth.
Interaction of cocaine‐, benztropine‐, and GBR12909‐like compounds with wild‐type and mutant human dopamine transporters: molecular features that differentially determine antagonist‐binding properties
Authors: Schmitt Kyle C. , Zhen Juan , Kharkar Prashant , Mishra Manoj , Chen Nianhang , Dutta Aloke K. , Reith Maarten E. A.
Published: September 2008

The widely abused psychostimulant cocaine is thought to elicit its reinforcing effects primarily via inhibition of the neuronal dopamine transporter (DAT). However, not all DAT inhibitors share cocaine’s behavioral profile, despite similar or greater affinity for the DAT. This may be due to differential molecular interactions with the DAT. Our previous work using transporter mutants with altered conformational equilibrium (W84L and D313N) indicated that benztropine and GBR12909 interact with the DAT in a different manner than cocaine. Here, we expand upon these previous findings, studying a number of structurally different DAT inhibitors for their ability to inhibit [3H]CFT binding to wild‐type, W84L and D313N transporters. We systematically tested structural intermediates between cocaine and benztropine, structural hybrids of benztropine and GBR12909 and a number of other structurally heterologous inhibitors. Derivatives of the stimulant desoxypipradrol (2‐benzhydrylpiperidine) exhibited a cocaine‐like binding profile with respect to mutation, whereas compounds possessing the diphenylmethoxy moiety of benztropine and GBR12909 were dissimilar to cocaine‐like compounds. In tests with specific isomers of cocaine and tropane analogues, compounds with 3α stereochemistry tended to exhibit benztropine‐like binding, whereas those with 3β stereochemistry were more cocaine‐like. Our results point to the importance of specific molecular features – most notably the presence of a diphenylmethoxy moiety – in determining a compound’s binding profile. This study furthers the concept of using DAT mutants to differentiate cocaine‐like inhibitors from atypical inhibitors in vitro. Further studies of the molecular features that define inhibitor–transporter interaction could lead to the development of DAT inhibitors with differential clinical utility.
Sphenopalatine Ganglion Radiofrequency Ablation for the Management of Chronic Cluster Headache
Authors: Narouze Samer , Kapural Leonardo , Casanova Jose , Mekhail Nagy
Published: September 2008

Objectives.— Chronic cluster headache patients are often resistant to pharmacological management. Percutaneous radiofrequency ablation (RFA) of the sphenopalatine ganglion (SPG) was shown before to improve episodic cluster headache but not chronic cluster headache. We were interested to examine the effect of such intervention in patients with intractable chronic cluster headache who failed pharmacological management.

Methods.— Fifteen patients with chronic cluster headache, who experienced temporary pain relief following SPG block, underwent percutaneous RFA via the infrazygomatic approach under fluoroscopic guidance. Collected data include demographic variables, onset and duration of the headache, mean attack intensity (MAI), mean attack frequency (MAF), and pain disability index (PDI) before and up to 18 months after procedure.

Results.— At 1‐, 3‐, 6‐, 12‐, 18‐month follow‐up, the MAI was 2.6, 3.2, 3.2, 3.4, 4.2, respectively (P < .0001, P < .0001, P < .0001, P < .0005, P < .003, respectively). The PDI improved from 55 (baseline) to 17.2 and 25.6 at 6 and 12 months respectively (P < .001). The MAF improved from 17 attacks/week to 5.4, 6.4, 7.8, 8.6, 8.3 at 1‐, 3‐, 6‐, 12‐, 18‐month follow‐up visits (P < .0001, P < .0001, P < .0001, P < .002, P < .004, respectively).

Conclusion.— Our data showed that percutaneous RFA of the SPG is an effective modality of treatment for patients with intractable chronic cluster headaches. Precise needle placement with the use of real‐time fluoroscopy and electrical stimulation prior to attempting radiofrequency lesioning may reduce the incidence of adverse events.
Serum Concentrations of s100b and NSE in Migraine
Authors: Teepker Michael , Munk Karoline , Mylius Veit , Haag Anja , Möller Jens C. , Oertel Wolfgang H. , Schepelmann Karsten
Published: September 2008

Background.— The protein s100b indicates astrocytal damage as well as dysfunction of the blood‐brain barrier (BBB), and neuron‐specific enolase (NSE) is regarded as a marker for neuronal cell loss. Recently, s100b was shown to be a potentially useful marker for migraine in children. In this study, we investigated the levels of s100b and NSE in adult migraineurs during and after migraine attacks in order to gain some more insight into migraine pathophysiology.

Methods.— Serum levels of s100b and NSE were measured in 21 migraineurs and compared with 21 healthy subjects matched by sex and age. In migraineurs, blood samples were taken during a migraine attack and following a pain‐free period of 2‐4 days.

Results.— During migraine attacks elevated s100b levels could be observed. Maximal concentrations were detected in the pain‐free period after 2‐4 days. Regarding NSE, serum levels were decreased slightly during and after migraine bouts.

Conclusions.— Our data suggest a prolonged disruption of BBB during and after migraine attacks. Other possible explanations concerning the detected serum levels of s100b and NSE will be discussed; however, neuronal cell death can be ruled out by the decreased serum concentrations of NSE. With regard to the results of the present study, further research is necessary to evaluate the role of s100b and NSE in migraine.
A Study to Evaluate the Feasibility of an Aerobic Exercise Program in Patients With Migraine
Authors: Varkey Emma , Cider Åsa , Carlsson Jane , Linde Mattias
Published: September 2008

Objectives.— The aim of this study was to develop and evaluate an exercise program to improve maximum oxygen uptake (VO2 max) in untrained patients with migraine without making their migraines worse.

Patients and methods.— Twenty‐six patients were studied at a headache clinic in Sweden. The exercise program, based on indoor cycling, was performed 3 times per week during 12 weeks. VO2 max, migraine status, side effects, and quality of life were evaluated.

Results.— VO2 max increased from 32.9 mL/kg/minute to 36.2 mL/kg/minute (P = .044). Quality of life increased and significant improvements in migraine status (attack frequency, symptom intensity, and intake of medicine) were seen. During the 12 weeks of exercise, on one occasion one patient had a migraine attack, which started immediately after training. No other side effects were reported.

Conclusions.— The evaluated exercise program was well tolerated by the patients and improved their VO2 max with no deterioration of migraine status.
Obesity in the Pediatric Headache Population: A Multicenter Study
Authors: Hershey Andrew D. , Powers Scott W. , Nelson Timothy D. , Kabbouche Marielle A. , Winner Paul , Yonker Marcy , Linder Steven L. , Bicknese Alma , Sowel Michael K. , McClintock William ,   the American Headache Society Pediatric Adolescent Section
Published: September 2008

Objective.— To examine the prevalence of obesity, the relationship between weight compared with headache frequency and disability, and effect of weight change on headache outcomes within a pediatric headache population.

Background.— Headache and obesity are both common conditions in children and adults. Research in adults has suggested a relationship between the 2 conditions. This relationship has not yet been explored within a pediatric population. The effect of obesity and weight change on headache outcomes may have important implications for clinical care.

Method.— Data on height, weight, age, and gender, as well as headache frequency and disability, were collected on 913 consecutive patients at 7 pediatric headache centers, the body mass index (BMI) calculated and the BMI percentile determined. The same data were collected on patients seen at 3‐ (n = 213) and 6‐month (n = 174) follow‐up for comparative analysis.

Results.— The prevalence of overweight patients at initial visit did not significantly differ from the general pediatric population. BMI percentile was significantly correlated with headache frequency and disability at initial visit, although the correlations were relatively small. For children who were obese or at risk for overweight as initial visit, change in BMI was significantly positively correlated with change in headache frequency at 3‐ and 6‐month follow‐up.

Conclusions.— Obesity is associated with headache frequency and disability in the pediatric headache population. For children who are overweight, weight loss can contribute to a reduction in headaches over time. Clinicians should consider child weight status in providing care for pediatric headache.
Cervical Mobility in Women With Migraine
Authors: Bevilaqua‐Grossi Debora , Pegoretti Katia S. , Goncalves Maria C. , Speciali José G. , Bordini Carlos A. , Bigal Marcelo E.
Published: September 2008

Objective.— To contrast the cervical range of motion (CROM) in women with episodic migraine (EM), transformed migraine (TM), and controls without migraine headaches.

Background.— Migraineurs often complain about neck pain. Furthermore, neck problems can worsen the headaches in individuals with migraine. Individuals with neck pain usually have reduced CROM. Nonetheless, studies assessing the CROM in migraineurs are scarce.

Methods.— Our sample was selected in an outpatient headache clinic, and consisted of 45 women aged 20‐54 years old, 15 per group. Cervical mobility was evaluated in movements of flexion, extension, right lateral flexion, left lateral flexion, right rotation, and left rotation using the CROM technique, and was contrasted among the groups. Migraine clinical patterns were also evaluated (frequency, duration of migraine, pain in the moment of evaluation, pain in movement, and pain localization) as a function of CROM.

Results.— Compared with controls, individuals with TM had numerically inferior CROM in all parameters, and significant reduction in 3 of them: extension (59.3 vs 68.1, P = .02), left lateral flexion (44.5 vs 49.1, P = .03), and right rotation (62.2 vs 69.6, P = .02). Compared with individuals with migraine, the TM group presented significantly reduced mobility only for extension (59.3 vs 68.4, P = .02). Migraineurs also had numerically inferior ROM, contrasted to controls, in 5 of the 6 parameters, although significance was seen just for right rotation (60.8 vs 68.6 P < .01). There was no correlation between cervical mobility and migraine parameters. The CROM was not reduced for the symptomatic side of migraine, in cases of unilateral pain.

Conclusion.— Contrasted to controls, individuals with episodic and TM have decreased cervical range of motion.
Analyzing the Effects of Market and Resource Orientations on Innovative Outcomes in Times of Turbulence*
Authors: Paladino Angela
Published: September 2008

Innovation and new product success are often a core precursor to superior performance. Although research has examined the resource‐based view (RBV) and market orientation (MO) individually, limited research has evaluated and compared their effect on innovation and new product success in one study. Furthermore, relative to MO, comparatively less research has been conducted to evaluate the relationship between organizational learning (OL) and the RBV to examine their effects on a firm's ability to innovate and succeed. The purpose of this paper is to investigate the role of environmental variables (i.e., market turbulence and technological turbulence) on the relationship between two strategic orientations and performance and to extend a previous study. Specifically, it aims to evaluate whether a focus on the customer or the firm will impact innovation, product quality, new product success, financial performance, and customer value in settings of varying environmental turbulence. Data were collected from more than 200 senior executives. LISREL was applied to evaluate the relationships under examination. Interaction effects were assessed using a nested goodness‐of‐fit strategy using a multiple‐group solution. Results depicted significant relationships between organizational learning and both resource and market orientations. Significant relationships also emerged between each strategic orientation and various performance indicators. Interaction effects were observed for market turbulence on customer value and market orientation as well as for resource orientation (RO) on innovation in times of high technological turbulence. The paper concludes with a review of theoretical and managerial implications to stimulate further debate. These results suggest that managers seeking innovation and new product success cannot afford to ignore the environment and do so at their peril. The provision of customer value is essential for positive financial performance. Thus, management needs to monitor environmental contexts so that they are able to adjust their investment in market orientation and the requisite processes that enable its implementation. Conversely, the effects of RO on performance are more robust across industry conditions, presenting an alternative avenue for management to achieve market superiority. The paper concludes with a review of theoretical and managerial implications to stimulate further debate.
Analogies and Mental Simulations in Learning for Really New Products: The Role of Visual Attention
Authors: Feiereisen Stephanie , Wong Veronica , Broderick Amanda J.
Published: September 2008

Really new products (RNPs) create new product categories or at least significantly expand existing ones. The development of RNPs is a strategic priority for most companies. However, 40% to 90% of new products fail, often due to consumers' lack of understanding of product features and benefits. Learning strategies, such as analogical learning and mental simulation, can help consumers understand the benefits of RNPs and thus may contribute to the successful development of marketing campaigns. Moreover, the presentation format of marketing communications is likely to influence consumers' understanding of the product. Pictorials have the potential to convey novel information without overloading the decision maker and thus may be a more efficient way to present information about RNPs than words. This paper contributes to a better understanding of consumer information processing in learning for RNPs. Study 1 examined the impact of (1) learning strategies (analogical learning vs. mental simulation) and (2) presentation formats (words vs. pictures) on product comprehension. Study 2 used an eye‐tracking experiment to assess how respondents' visual attention patterns may affect product comprehension. Study 1 showed that the use of words in marketing communications for RNPs is generally more effective to enhance product comprehension than the use of pictorials. However, the video glasses were a notable exception as the combination of mental simulation and pictures yielded a high comprehension level for this product. This suggests that the use of pictorials may be appropriate to convey information for products of a more hedonic as opposed to utilitarian nature. Study 2 used a combination of eye‐tracking measures and self‐reports to help illuminate the cognitive processes at work when consumers learn new product information. The results suggest that an increase in attention to an element of the advert can account for one of two underlying processes: (1) an increase in comprehension; or (2) a difficulty to understand product information which may result in consumer confusion. This study adds evidence to a growing body of literature that demonstrates the power of learning strategies such as mental simulation and analogical learning in preparing consumers for new product acceptance. The use of visual stimuli contributes to the debate on the effectiveness of words versus pictures, seldom applied in a new product development (NPD) context. These findings are integrated into a discussion of the managerial implications and the potential avenues for future research in the area.
The Global Brain by Satish Nambisan and Mohanbir Sawney
Authors: Feldman Laurence P.
Published: September 2008

Books reviewed in this issue:

The Global Brain

Do It Wrong Quickly: How the Web Changes the Old Marketing Rules

Reinventing Project Management: The Diamond Approach to Successful Growth and Innovation

Selling Blue Elephants: How to Make Great Products that People Want before They Even Know They Want Them
Facial Soft Tissue Depths in Craniofacial Identification (Part I): An Analytical Review of the Published Adult Data*
Authors: Stephan Carl N. , Simpson Ellie K.
Published: September 2008

Abstract:  With the ever increasing production of average soft tissue depth studies, data are becoming increasingly complex, less standardized, and more unwieldy. So far, no overarching review has been attempted to determine: the validity of continued data collection; the usefulness of the existing data subcategorizations; or if a synthesis is possible to produce a manageable soft tissue depth library. While a principal components analysis would provide the best foundation for such an assessment, this type of investigation is not currently possible because of a lack of easily accessible raw data (first, many studies are narrow; second, raw data are infrequently published and/or stored and are not always shared by some authors). This paper provides an alternate means of investigation using an hierarchical approach to review and compare the effects of single variables on published mean values for adults whilst acknowledging measurement errors and within‐group variation. The results revealed: (i) no clear secular trends at frequently investigated landmarks; (ii) wide variation in soft tissue depth measures between different measurement techniques irrespective of whether living persons or cadavers were considered; (iii) no clear clustering of non‐Caucasoid data far from the Caucasoid means; and (iv) minor differences between males and females. Consequently, the data were pooled across studies using weighted means and standard deviations to cancel out random and opposing study‐specific errors, and to produce a single soft tissue depth table with increased sample sizes (e.g., 6786 individuals at pogonion).
Facial Soft Tissue Depths in Craniofacial Identification (Part II): An Analytical Review of the Published Sub‐Adult Data*
Authors: Stephan Carl N. , Simpson Ellie K.
Published: September 2008

Abstract:  Prior research indicates that while statistically significant differences exist between subcategories of the adult soft tissue depth data, magnitudes of difference are small and possess little practical meaning when measurement errors and variations between measurement methods are considered. These findings raise questions as to what variables may or may not hold meaning for the sub‐adult data. Of primary interest is the effect of age, as these differences have the potential to surpass the magnitude of measurement error. Data from the five studies in the literature on sub‐adults which describe values for single integer age groups were pooled and differences across the ages examined. From 1 to 18 years, most soft tissue depth measurements increased by less than 3 mm. These results suggest that dividing the data for children into more than two age groups is unlikely to hold many advantages. Data were therefore split into two groups with the division point corresponding to the mid‐point of the observed trends and main data density (0–11 and 12–18 years; division point = 11.5 years). Published sub‐adult data for seven further studies which reported broader age groups were pooled with the data above to produce the final tallied soft tissue depth tables. These tables hold the advantages of increased sample sizes (pogonion has greater than 1770 individuals for either age group) and increased levels of certainty (as random and opposing systematic errors specific to each independent study should average out when the data are combined).
The C3H/HeJ mouse and DEBR rat models for alopecia areata: review of preclinical drug screening approaches and results
Authors: Sun Jing , Silva Kathleen A. , McElwee Kevin J. , King Jr. Lloyd E. , Sundberg John P.
Published: September 2008

Abstract:  The C3H/HeJ inbred mouse strain and the Dundee Experimental Bald Rat (DEBR) strain spontaneously develop adult onset alopecia areata (AA), a cell‐mediated disease directed against actively growing hair follicles. The low frequency of AA and the inability to predict the stage of AA as it evolves in the naturally occuring C3H/HeJ model of AA can be converted into a highly predictable system by grafting full thickness skin from AA‐affected mice to normal haired mice of the same strain. The rat DEBR model develops spontaneous AA at a higher frequency than in the mouse model but they are more expensive to use in drug studies owing to their larger size. Regardless of the shortcomings of either model, these rodent models can be used succesfully to screen novel or approved drugs for efficacy to treat human AA. As the pathogenesis of AA follows the canonical lymphocytic co‐stimulatory cascade in the mouse AA model, it can be used to screen compounds potentially useful to treat a variety of cell‐mediated diseases. Efficacy of various agents can easily be screened by simply observing the presence, rate, and cosmetic acceptability of hair regrowth. More sophisticated assays can refine how the drugs induce hair regrowth and evaluate the underlying pathogenesis of AA. Some drugs commonly used to treat human AA patients work equally as well in both rodent models validating their usefulness as models for drug efficacy and safety for humanAA.
Local effects of TL01 phototherapy in psoriasis
Authors: DeSilva Bernadette , McKenzie Roddie C. , Hunter John A. A. , Norval Mary
Published: September 2008

The mechanisms whereby narrowband ultraviolet B (UVB) (311–313 nm, TL01) phototherapy are effective in psoriasis may differ from those occurring in broadband UVB phototherapy. In the present study, changes in epidermal cells as a result of TL01 therapy were assessed in the skin of patients with psoriasis. The non‐lesional skin of five subjects with plaque psoriasis was biopsied before and after a series of 12 whole‐body TL01 treatments. Following appropriate staining of skin sections, the numbers of p53‐positive keratinocytes, sunburn cells and Langerhans cells in the epidermis were counted. TL01 therapy induced a threefold increase in the number of p53‐positive epidermal cells, a 12‐fold increase in sunburn cells and a twofold decrease in Langerhans cells. The increase in epidermal p53 expression and apoptosis of keratinocytes together with the depletion of Langerhans cells in the non‐lesional skin of psoriasis patients are likely to contribute to the effectiveness of TL01 phototherapy.
Role of photodynamic therapy in psoriasis: a brief review
Authors: Tandon Yasmeen K. , Yang Marjorie F. , Baron Elma D.
Published: September 2008

Background and purpose: Photodynamic therapy (PDT) is a light treatment modality which involves either systemic or local application of a photosensitizing compound, which preferentially deposits in the target cells, and is then followed by selective illumination of the lesion with visible light. The purpose of this study was to review the literature to examine the success, side effects, and different protocols used thus far to treat psoriasis using PDT.

Methods: A thorough review of the literature was performed and analyzed.

Results and conclusions: After a thorough review of the literature, PDT remains a potential treatment for psoriasis. Clinical improvement has been observed in most studies. The major limiting factor seen in many of the studies was the side effect of pain and burning sensations associated with PDT. This highlights the need for other photosensitizers with better tolerability profiles.
Alveolar Ridge Regeneration with Equine Spongy Bone: A Clinical, Histological, and Immunohistochemical Case Series
Authors: Di Stefano Danilo Alessio , Artese Luciano , Iezzi Giovanna , Piattelli Adriano , Pagnutti Stefano , Piccirilli Marcello , Perrotti Vittoria
Published: September 2008

Background: In the case of localized ridge atrophy, a ridge augmentation procedure, with the use of bone substitutes and barrier membranes, may then be necessary.

Purpose: The aim of the present study was a clinical, histological, and immunohistochemical evaluation of an equine spongy bone in alveolar ridge augmentation procedures.

Materials and Methods: Five patients showing horizontal mandibular ridge defects participated in this study. A ridge augmentation was performed through an onlay apposition of equine bone covered by a titanium‐reinforced membrane. After 6 months of healing, five bone cores from nonaugmented sites (control) and five from augmented sites (test) were retrieved.

Results: In test sites, no postoperative complications occurred. Horizontal bone width increased from ≤4 to ≥7 mm. In control sites, the newly formed bone represented 33%, and in test sites, 35% of the total area. The mean value of the microvessel density was 25.6 +/– 3.425 per mm2 in controls, while 33.3 +/– 2.5 vessels per mm2 in the test sites were found (p < .05). Both groups showed a high intensity (++) of vascular endothelial growth factor expression in the newly formed bone, while a low intensity (+) was found in the mature bone.

Conclusion: Equine bone appeared to be biocompatible and to be associated with new vessel ingrowth. Within the limits of the small sample size, the present study indicated that equine bone could be used in mandibular ridge augmentations.
Apical Peri‐Implantitis: Possible Predisposing Factors, Case Reports, and Surgical Treatment Suggestions
Authors: Dahlin Christer , Nikfarid Hossein , Alsén Bengt , Kashani Hossein
Published: September 2008

Background: Apical peri‐implantitis is often diagnosed by clinical findings such as pain, redness, tenderness, swelling, and sometimes the presence of a fistulous tract. There are few theories about how such a lesion occurs. Hence, the current clinical treatment protocols are scanty.

Purpose: The aim of this report was to evaluate and confer a more extended surgical protocol and to discuss possible predisposing factors for the development of retrograde peri‐implantitis.

Materials and Methods: Two patients were extensively evaluated with regard to clinical signs, implant treatment, postoperative complications, and surgical treatment. The surgical protocol comprised debridement, with the additional removal of the apical portion of the affected implant. Postoperative checkup included clinical examination and radiographs. The follow‐up period ranged from 1 to 3 years following surgical debridement. The possible predisposing factors are also discussed in the article.

Results: Both cases healed uneventfully with no further symptoms. Radiographs revealed complete bone fill into the resected area and continuous stable bone levels around the previously affected implants.

Conclusions: It is concluded that recommendations for treatment of apical peri‐implantitis are still minimal. In the present study, a surgical approach with resection of the apical portion of the affected implants in combination with debridement is suggested. Our experience was that partially resected oral implants remain osseointegrated and also function well clinically with a follow‐up period up to 3 years.
Within‐Subject Comparison of Two Rigid Bar Designs Connecting Two Interforaminal Implants: Patients' Satisfaction and Prosthetic Results
Authors: Mericske‐Stern Regina , Probst Dieter , Fahrländer Fritz , Schellenberg Marc
Published: September 2008

Background: There is evidence for the superiority of two‐implant overdentures over complete dentures in the mandible. Various anchorage devices were used to provide stability to overdentures. The aim of the present study was to compare two designs of a rigid bar connecting two mandibular implants.

Materials and Methods: Completely edentulous patients received a new denture in the maxilla and an implant‐supported overdenture in the mandible. They were randomly allocated to two groups (A or B) with regard to the bar design. A standard U‐shaped bar (Dolder bar) was used connecting the two implants in a straight line. For comparison, precision attachments were soldered distal to the bar copings. Group A started the study with the standard bar (S‐bar), while group B started with the attachment‐bar (A‐bar). After 3 months, they had to answer a questionnaire (visual analogue scale [VAS]); then the bar design was changed in both groups. After a period of another 3 months, the patients had to answer the same questions; then they had the choice to keep their preferred bar. Now the study period was extended to another year of observation, and the patients answered again the same questionnaire. In vivo force measurements were carried out with both bar types at the end of the test periods. The prosthetic maintenance service carried out during the 6‐month period was recorded for both bar types in both groups. Statistical analysis as performed with the SPSS statistical package (SPSS Inc., Chicago, IL, USA).

Results: Satisfaction was high in both groups. Group B, who had entered the study with the attachment bar, gave slightly better ratings to this type for four items, while in group A, no differences were found. At the end of the 6‐month comparison period, all but one patient wished to continue to wear the attachment bar. Prosthetic service was equal in groups A and B, but the total number of interventions is significantly higher in the attachment bar. Force patterns of maximum biting were similar in both bar designs, but exhibited significantly higher axial forces in the attachment bar.

Conclusions: Both bar designs provide good retention and functional comfort. High stability appears to be an important factor for the patients' satisfaction and oral comfort. Rigid retention results in a higher force impact and appears to evoke the need for the retightening of occlusal screws, resulting in more maintenance service.
Digitally Planned, Immediately Loaded Dental Implants with Prefabricated Prostheses in the Reconstruction of Edentulous Maxillae: A 1‐Year Prospective, Multicenter Study
Authors: Johansson Björn , Friberg Bertil , Nilson Hans
Published: September 2008

Background: The introduction of digital planning programs has made it possible to place dental implants in preplanned positions and being immediately functionally loaded by using prefabricated prostheses.

Purpose: The aim of this multicenter study was to describe the 1‐year results of digitally planned, immediately loaded edentulous maxillae.

Materials and Methods: A total of 312 implants (Brånemark System®, TiUnite RP, Nobel Biocare, Göteborg, Sweden) in 52 patients from eight Scandinavian clinics were digitally planned, surgically as well as prosthetically, by using the NobelGuide® (Nobel Biocare AB, Göteborg, Sweden) and received prefabricated, immediately loaded fixed prosthetic constructions in the maxillae. Individual implant stability was manually tested at 1‐year follow‐up.

Results: All patients received a Procera Implant Bridge® (Nobel Biocare AB); however, in two cases, the bridges were reconstructed due to misfit. In five patients, difficulties in getting the surgical guide completely in position, and in five patients, getting the prostheses completely seated, were noted.

All but four patients fulfilled the 1‐year follow‐up. Two implants were lost during the study period, resulting in a cumulative survival rate of 99.4%. The mean marginal bone resorption from implant placement to the 1‐year follow‐up was 1.3 mm (SD 1.28). More than 2 mm of marginal resorption was noted in 19% of the implants at this instant. The most frequently reported complications during the first year were gingival hyperplasia and prosthesis‐related problems (prosthesis screw loosening, occlusal fractures, and occlusal adjustments).

Conclusion: The 1‐year results in this multicenter are promising regarding implant and bridge stability; however, the study is planned to be running for at least 3 years.
RFA Values of Implants Placed in Sinus Grafted and Nongrafted Sites after 6 and 12 Months
Authors: Degidi Marco , Daprile Giuseppe , Piattelli Adriano
Published: September 2008

Background: Maxillary sinus floor elevation surgery is widely used as a preimplantology method to permit implant insertion. Nevertheless, very few data are available about long‐term stability of dental implants inserted in grafted sites.

Purpose: The aims of the present study were to evaluate the evolution of resonance frequency analysis (RFA) values at 6 and 12 months from the implant insertion in sinus grafted sites and nongrafted sites.

Materials and Methods: In 14 patients, 80 Xive implants (Dentsply Friadent GmbH, Mannheim, Germany) were inserted. Sixty‐three implants were inserted in a site previously treated with a sinus lift; 17 implants were inserted in healed or postextraction sites. For each implant diameter, length, bone density, insertion torque, and percentage of implant fixed to a nongrafted bone were recorded. RFA values at implant insertion after 6 and 12 months were recorded.

Results: After 6 and 12 months, grafted sites showed higher RFA values than the control sites; after 12 months, the difference was statistically significant (.007). A statistically significant positive correlation was found between resonance frequency values and bone quality after 12 months (.05). No statistically significant correlation between RFA values and all the other variables considered was found.

Conclusions: Sites treated with sinus lift can offer good long‐term stability. After 6 and 12 months, the geometric characteristics of the implant are no longer important to obtain high RFA values, and the bone–implant interface seems to be determinant.
Stability of Prototype Two‐Piece Zirconia and Titanium Implants after Artificial Aging: An In Vitro Pilot Study
Authors: Kohal Ralf‐Joachim , Finke Hans Christian , Klaus Gerold
Published: September 2008

Background: Zirconia oral implants are a new topic in implant dentistry. So far, no data are available on the biomechanical behavior of two‐piece zirconia implants. Therefore, the purpose of this pilot investigation was to test in vitro the fracture strength of two‐piece cylindrical zirconia implants after aging in a chewing simulator.

Materials and Methods: This laboratory in vitro investigation comprised three different treatment groups. Each group consisted of 16 specimens. In group 1, two‐piece zirconia implants were restored with zirconia crowns (zirconia copings veneered with Triceram®; Esprident, Ispringen, Germany), and in group 2 zirconia implants received Empress® 2 single crowns (Ivoclar Vivadent AG, Schaan, Liechtenstein). The implants, including the abutments, in the two zirconia groups were identical. In group 3, similar titanium implants were reconstructed with porcelain‐fused‐to‐metal crowns. Eight samples of each group were submitted to artificial aging with a long‐term load test in the artificial mouth (chewing simulator). Subsequently, all not artificially aged samples and all artificially aged samples that survived the long‐term loading of each group were submitted to a fracture strength test in a universal testing machine.

For the pairwise comparisons in the different test groups with or without artificial loading and between the different groups at a given artificial loading condition, the Wilcoxon rank‐sum test for independent samples was used. The significance level was set at 5%.

Results: One sample of group 1 (veneer fracture), none of group 2, and six samples of group 3 (implant abutment screw fractures) failed while exposed to the artificial mouth. The values for the fracture strength after artificial loading with 1.2 million cycles for group 1 were between 45 and 377 N (mean: 275.7 N), in group 2 between 240 and 314 N (mean: 280.7 N), and in the titanium group between 45 and 582 N (mean: 165.7 N). The fracture strength results without artificial load for group 1 amounted to between 270 and 393 N (mean: 325.1 N), for group 2 between 235 and 321 N (mean: 281.8 N), and between 474 and 765 N (mean: 595.2 N) for the titanium group. The failure mode during the fracture testing in the zirconia implant groups was a fracture of the implant head and a bending/fracture of the abutment screw in the titanium group.

Conclusions: Within the limits of this pilot investigation, the biomechanical stability of all tested prototype implant groups seems to be – compared with the possibly exerted occlusal forces – borderline for clinical use. A high number of failures occurred already during the artificial loading in the titanium group at the abutment screw level. The zirconia implant groups showed irreparable implant head fractures at relatively low fracture loads. Therefore, the clinical use of the presented prototype implants has to be questioned.
Comparative Analysis of Immediate Functional Loading and Immediate Nonfunctional Loading to Traditional Healing Periods: A 5‐Year Follow‐Up of 550 Dental Implants
Authors: Degidi Marco , Iezzi Giovanna , Perrotti Vittoria , Piattelli Adriano
Published: September 2008

Background: Clinical, radiographical, and histological findings have shown that immediately loaded implants show the presence of mineralized tissues at the interface.

Purpose: The aim of this study was to compare an immediate loading protocol with a two‐staged one using an implant with a square thread design.

Materials and Methods: One hundred fifty‐five consecutive patients (71 men, 84 women), aged between 18 and 78 years (mean: 54 years) participated in this study. A total of 550 implants (Maestro; BioHorizons, Birmingham, AL, USA) were inserted. In group A, 264 implants were inserted in 82 patients with immediate functional loading with occlusal contact if the patients were completely edentulous, or with immediate nonfunctional loading without occlusal contact if the patients were partially edentulous. In group B, 286 implants were inserted in 73 patients with a one‐stage or two‐stage surgical procedure. All patients were followed for at least 5 years.

Results: In the immediately loaded implants group, three implants failed, all in posterior mandibular sites, with an overall 98.8% 5‐year survival rate. In the control group, no implant failed, with a 100% 5‐year survival rate. No statistically significant differences were found in the survival rates of the implants in the two groups.

Discussion: A very high implant survival rate was also present in our series for the immediately loaded implants. All the three failed implants were retrieved from the same patient, who had poor oral hygiene, after a loading period of 5 years. These data can suggest that, from a clinical point of view, an abbreviated healing period is compatible with the development and maintenance over a longer time period (5 years) of mineralized tissues at the interface with dental implants.

Conclusion: We can then conclude that shorter healing periods can be highly satisfactory from a clinical point of view.
Outcome of Brånemark Novum® Implant Treatment in Edentulous Mandibles: A Retrospective 5‐Year Follow‐Up Study
Authors: Gualini Federico , Gualini GianLuigi , Cominelli Roberto , Lekholm Ulf
Published: September 2008

Background: A gradual progression from a two‐stage surgical technique to a one‐stage and even immediate surgical protocol has occurred during the last decade with most oral implant systems. However, every new approach must obviously be reported individually, with long‐term results, in order to assess whether the changes have any real patient value.

Purpose: The aim of the present report was to retrospectively review the 5‐year outcome of patients treated with the Brånemark Novum® (Nobel Biocare AB, Göteborg, Sweden) protocol.

Methods: The first 15 patients treated according to the Novum procedure in a private specialist clinic in Lovere, Italy, were followed‐up with clinical, radiographic, and resonance frequency analyses. All the patients’ fixed constructions had been in function for an average of 5 years. Parameters recorded were implant survival, prosthesis success, oral hygiene and mucosal health, marginal bone remodeling, type and frequency of complications, and patient's opinion of the treatment outcome.

Results: After 5 years, the cumulative survival rate for implants was 91%, and for inserted bridge constructions it was 87%. Very small changes in implant stability occurred during implant loading from 1 to 5 years. Oral health conditions were good; 87% of mucosal quadrants around the implants were free from signs of inflammation. Very small marginal bone height changes were observed at the implants during the examination period, and except for four implant losses reported, severe complications were few. All patients were satisfied with the functional outcome of their constructions, but two patients were not completely happy with the aesthetics of their bridgework as supplied.

Conclusion: This report shows 5‐year evidence of acceptably good results with the Brånemark Novum implant technique in edentulous mandibles, when using only three implants to support the fixed bridge construction, and as long as inserted implants become and remain osseointegrated.
Early Laser‐Welded Titanium Frameworks Supported by Implants in the Edentulous Mandible: A 15‐Year Comparative Follow‐Up Study
Authors: Örtorp Anders , Jemt Torsten
Published: September 2008

Background: Comparative long‐term knowledge of different framework materials in the edentulous implant patient is not available for 15 years of follow‐up.

Purpose: To report and compare a 15‐year retrospective data on implant‐supported prostheses in the edentulous mandible provided with laser‐welded titanium frameworks (test) and gold alloy frameworks (control).

Materials and Methods: Altogether, 155 patients were consecutively treated with abutment‐level prostheses with two early generations of fixed laser‐welded titanium frameworks (titanium group). Fifty‐three selected patients with gold alloy castings formed the control group. Clinical and radiographic 15‐year data were collected and compared for the groups.

Results: All patients who were followed up for 15 years (n = 72) still had a fixed prosthesis in the mandible at the termination of the study. The 15‐year original prosthesis cumulative survival rate (CSR) was 89.2 and 100% for titanium and control frameworks (p = .057), respectively (overall CSR 91.7%). The overall 15‐year implant CSR was 98.7%. The average 15‐year bone loss was 0.59 mm (SD 0.56) and 0.98 mm (SD 0.64) for the test and control groups (p = .027), respectively. Few (1.3%) implants had >3.1‐mm accumulated bone loss after 15 years. The most common complications for titanium frameworks were resin or veneer fractures and soft tissue inflammation. Fractures of the titanium metal frame were observed in 15.5% of the patients. More patients had framework fractures in the earliest titanium group (Ti‐1 group) compared to the gold alloy group (p = .034). Loose and fractured implant screw components were few (2.4%).

Conclusion: Predictable overall long‐term results could be maintained with the present treatment modality. Fractures of the metal frames and remade prostheses were more common in the test group, and the gold alloy frameworks had a tendency to work better when compared with welded titanium frameworks during 15 years. However, on the average, more bone loss was observed for implants supporting gold alloy frameworks.