1,720,983 research outputs found
Modulation of clinical expression of plaque-induced gingivitis: effects of personality traits, social support and stress.
No full textBACKGROUND: Studies have shown an association between an acute stressful event and gingivitis. However, the possible effects of personality traits associated with stress resistance/susceptibility and current level of stress on the clinical expression of plaque-induced inflammation remain to be examined. The aim of this study was to characterize the subject-based clinical behaviour of the gingiva during experimental gingivitis in relation to personality profile, psychological stress and coping behaviour. METHODS: Ninety-six systemically and periodontally healthy subjects (mean age: 23.6+/-1.7 years), 46 males and 50 females, non-smokers, participated in a randomized, split-mouth, localized experimental gingivitis trial. Prior to the trial, subjects were asked to complete self-administered questionnaires evaluating personality traits (Hardiness scale and Courtauld Emotional Control Scale), subjective stress (Visual Analogue Scale-Total Distress), social support (Multidimensional Scale of Perceived Social Support, MSPSS) and life events (Life Experiences Survey (LES)). The influence of psychosocial factors was investigated in the overall population as well as in two sub-populations with different inflammatory response to plaque accumulation. RESULTS: No significant relationships were found between gingival inflammation variables and psychological measures. No significant differences were detected between subjects with different susceptibilties to plaque-associated gingivitis for any considered psychological variable. A significant association between plaque variables and LES (negative) or MSPSS (positive) was found; however, the variance explained by the model was low. CONCLUSIONS: Differences in the current level of stress and psychosocial variables indicative of stress susceptibility do not account for variability in plaque accumulation and gingival inflammation during experimental gingivitis in young adults
Modulation of clinical expression of plaque-induced gingivitis: response in aggressive periodontitis subjects
No full textAIM: The aim of this study was to characterize the gingival inflammatory response to de novo plaque accumulation in subjects treated for aggressive periodontitis (AP). The gingival inflammatory response of the AP subjects was retrospectively compared with that of periodontally healthy individuals (PH) matched for exposure to plaque and of periodontally healthy subjects previously identified as "high responders" (HR) and "low responders" (LR). MATERIALS AND METHODS: 13 AP subjects and 26 matched PH subjects participated in a 21-day experimental gingivitis trial. Plaque index (PlI), Gingival index (GI), gingival crevicular fluid volume (GCF) and angulated bleeding score (AngBS) were recorded at days 0, 7, 14 and 21. Cumulative plaque exposure (CPE), i.e. PlI over time, was also calculated. RESULTS: GCF was significantly higher in AP compared with PH group at each observation interval (p< or =0.001). In addition, GCF was significantly higher in AP group compared with either LR or HR groups at each observation interval (p<0.001). CONCLUSIONS: These results suggest that susceptibility to gingival inflammation in response to de novo plaque accumulation may be related to susceptibility to periodontitis
Time as a factor in the identification of subjects with different susceptibility to plaque-induced gingivitis
No full textOBJECTIVES: The purpose of this study was to assess whether identification of subjects with different susceptibility to plaque-induced gingival inflammation is dependent on the length of time of de novo plaque accumulation. METHODS: Retrospective analysis of data obtained from a recently reported randomized split-mouth localized experimental gingivitis trial involving 96 healthy non-smokers. Gingival and plaque index, gingival crevicular fluid volume (GCF), angulated bleeding score, and the derived parameter cumulative plaque exposure (CPE) were recorded at days 0, 7, 14, and 21. The primary outcome variable to express severity of inflammation was GCF and each subject was a statistical unit. Based on subject distribution of GCF-day 21 residuals after standardization for CPE-day 21, two sub-populations (upper and lower distribution quartiles) were selected. They were, respectively, defined as "high responders" (HR) (n=24) and "low responders" (LR) (n=24) and characterized by significantly different severity of gingivitis to similar amounts of plaque deposits. The same analysis was repeated at days 7 and 14. Prevalence of HR and LR was compared between days using the chi(2) [ML] test. RESULTS: For both day 7 and day 14, the quartile distribution of LR and HR was statistically significant (p=0.02). Fifty percent of LR and 71% of HR presented a consistent level of susceptibility to plaque-induced gingival inflammation even after only 7 and/or 14 days of plaque accumulation. CONCLUSIONS: These findings support the concept that the subject-based susceptibility to plaque-induced gingival inflammation is an individual trait, only partly related to the length of time of exposure to plaque
Modulation of clinical expression of plaque-induced gingivitis: Interleukin-1 gene cluster polymorphisms
No full textBACKGROUND: The purpose of the present study was to determine the association of interleukin-1 (IL-1) gene polymorphisms with clinical parameters of gingivitis in a large experimental gingivitis trial and with each of two subgroups, high responders (HR) and low responders (LR), with distinct susceptibility to gingivitis. METHODS: Ninety-six systemically and periodontally healthy non-smokers, 46 males (mean age: 23.9+/-1.7) and 50 females (mean age: 23.3+/-1.6) were included in a randomized, split-mouth, localized 21-day experimental gingivitis trial. Plaque index (PI), gingival index (GI), gingival crevicular fluid volume (GCF), and angulated bleeding score (AngBS) were recorded. Two subgroups were defined from the total study population (HR, LR) characterized by substantially different severity of gingival inflammation despite similar plaque accumulation rate. The study population was typed for interleukin-1 alpha (IL-1A+4845), interleukin-1 beta (IL-1B+3953, IL-1B-511), and IL-1 receptor antagonist (IL-1RN, intron 2 variable number tandem repeats) gene polymorphisms. Gene variants were analyzed by amplifying the polymorphic region using polymerase chain reaction, followed by restriction-enzyme digestion and agarose gel electrophoresis. RESULTS: Neither IL-1A+4845, IL-1B+3953, or the combined (IL-1A+4845 x 2 - IL-1B+3953 x 2) genotype was associated with clinical parameters in the overall population. IL-1RN was significantly associated with test quadrant PI (P= 0.046), GCF (P= 0.05), and GI (P= 0.018). The genotype distribution in HR and LR subjects was significantly different for IL-1RN (P= 0.045) and for IL-1B-511 (P= 0.023). CONCLUSION: The results of the present study suggest an association between IL-1RN polymorphism and subject-based clinical behavior of the gingiva in response to de novo plaque accumulation, as well as a possible association between IL-1B-511 polymorphism and gingivitis susceptibility
GTR with bioabsorbable membrane in the treatment of human gingival recession defects
No full textThe purpose of the present study was to evaluate the effect of GTR procedure in comparison to subpedicle connective tissue graft (SCTG) in the treatment of gingival recession defects. A total of 12 patients, each contributing a pair of Miller's Class I or II buccal gingival recessions was treated. According to a randomization list, in each patient one defect received a polyglycolide/lactide bioabsorbable membrane, while the paired defect received a SCTG. Treatment effect was evaluated 6 months postsurgery. Clinical recordings included full-mouth and defect-specific oral hygiene standards and gingival health, recession depth (RD), recession width (RW), probing depth (PD), clinical attachment level (CAL) and keratinized tissue (KT). Mean RD significantly decreased from 3.1 mm presurgery to 1.5 mm at 6 months postsurgery fo the GTR group (48% root coverage), and from 3.0 mm to 0.5 mm for the SCTG group (81% root coverage). RD reduction and root coverage were significantly greater in SCTG group compared to GTR group. No significant differences in PD changes were observed within and between groups. KT increased significantly from presurgery for both treatment groups, however gingival augmentation was significantly greater in the SCTG group compared to GTR group. Results indicate that 1) treatment of human gingival recession defects by means of both GTR and SCTG procedures results in clinically and statistically significant improvement of soft tissue conditions of the defect, and 2) treatment outcome was significantly better following SCTG compared to GTR in terms of recession depth reduction, root coverage and keratinized tissue increase. This study was partly supported by W.L. Gore Associates Inc. and MURST Grant #96/60/06/01
Experimental Gingivitis: Reproducibility of Plaque Accumulation and Gingival Inflammation Parameters in Selected Populations during a Repeat Trial.
No full textObjectives: To assess whether and to what extent the experimental gingivitis clinical parameters are reproducible within selected populations with different gingival inflammatory response (high or low) to plaque accumulation. In addition, the consistency in developing a high or low gingival inflammatory response within the selected populations was evaluated. Methods: 37 subjects previously identified as high (HR, n=20) or low responders (LR, n=17) during an experimental gingivitis trial (1st trial) (Trombelli et al. 2004) were enrolled in a “repeat” experimental gingivitis trial. Results: No significant differences in plaque accumulation parameters and bleeding index values were detected between 1st and repeat trial for the 37 participants. Gingival Index (GI) was higher during the repeat trial but behaved consistently in terms of the temporal changes in the course of both trials in both populations. Of the 17 LR participants, 10 manifested low susceptibility to inflammation after repeat trial. Among the 20 HR, 10 manifested high susceptibility to inflammation after repeat trial. Conclusions: these results indicate that our experimental gingivitis model is reproducible to some extent in selected populations. The high reproducibility of plaque and, to a lesser extent, of inflammation parameters under the employed controlled conditions could be a valuable tool in gingivitis research
Modulation of clinical expression of plaque-induced gingivitis - III. Response of "high responders" and "low responders" to therapy
No full textAIM: The aim of the present study was to characterize the subject-based clinical behavior of the gingiva in response to a tooth-cleaning regimen in two subpopulations, "high-responder" (HR) and "low-responder" (LR) groups, presenting a different inflammatory response to plaque accumulation. MATERIAL AND METHODS: The study population comprised of 96 systemically and periodontally healthy subjects, 46 males and 50 females, non-smokers, enrolled in an experimental gingivitis trial. At completion of the experimental gingivitis period (day 21), all subjects were prescribed the same 21-day treatment regimen of amine/stannous fluoride (AmF/SnF(2))-containing toothpaste and mouthrinse. Plaque index (PlI), gingival index (GI), gingival crevicular fluid volume (GCF), and angulated bleeding score (AngBS) were recorded on three selected teeth. Treatment efficacy was evaluated in the overall population as well as in HR and LR groups, separately. RESULTS: A statistically significant decrease of PlI was observed after treatment (p<0.001), with PlI reversing to baseline levels. Changes in PlI revealed the same trend in both HR and LR groups, without differences between groups. Treatment also resulted in a significant decrease of all gingivitis parameters (p<0.001 for all comparisons). After treatment, GI, AngBS, and GCF were comparable with baseline condition. However, when the two groups were compared, day 42-GCF was significantly higher in the HR group than the LR group. CONCLUSIONS: A treatment regimen based on mechanical plaque control supplemented with AmF/SnF(2)-containing toothpaste and mouthrinse is effective in reducing plaque accumulation and re-establishing healthy gingival conditions after experimentally induced gingivitis, even in subjects with different inflammatory response to plaque accumulation
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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