bluuebunny/crossref_metadata_2025 huggingface dataset:
Periodontopathogens in elderly Chinese with different periodontal disease experience
Authors: Dahlén Gunnar G. , Luan Wen‐Min , Baelum Vibeke , Fejerskov Ole , Chen Xia
Published: August 2010

Abstract If an etiological relationship exists between destructive periodontal disease and putative periodontopathogens, they would be expected to have a very low prevalence in periodontally healthy elderly persons. To test this hypothesis, 2 subgroups of elderly, rural Chinese (a periodontally “best” and a “worst” group, each comprising 15 persons) were identified in 1990 from a cohort aged 55–69 years, examined in 1984. Assessment of changes in periodontal status over the 6‐year period were possible by comparing detailed clinical recordings performed by the same examinator. Subgingival microbial samples were taken at the mesial aspects of an upper central incisor and a lower canine and examined for the presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingi‐valis, Prevotella intermedia group, Prevotella melaninogenica group, Capnocyto‐phaga, Selenomonas, Campylobacter rectus as well as predominant Streptococcus and Actinornyces species. During the 6 years prior to microbiological sampling, persons in the “best” group had lost an average of 1.21 ±0.48 mm attachment, while persons in the “worst” group had lost an average of 1.60±0.94 mm. The latter group had lost 53.3 teeth, predominantly for periodontal reasons, in contrast to 1.8 teeth lost in the “best” group. “Best” persons did not differ from “worst” persons with respect to the occurrence of the putative periopathog‐ens, total viable count, and total streptococcal and Actinomyces recovery. Similarly, sites which had experienced an attachment loss 2 mm during the 6‐year period did not differ microbiologically from sites with less attachment loss. It is concluded that subgingival microbial characterization does not allow for a distinction between elderly individuals with markedly different periodontal disease experiences.
Effect of cigarette smoking on periodontal healing following GTR in infrabony defects
Authors: Tonetti Maurizio S. , Pini‐Prato Giovanpaolo , Cortellini Pierpaolo
Published: August 2010

Abstract This retrospective study examined the effect of cigarette smoking on the healing response following guided tissue regeneration (GTR) in deep infrabony defects. 71 defects in 51 patients underwent GTR with teflon membranes. 20 patients (32 defects) smoked more than 10 cigarettes per day, while 31 patients (39 defects) did not smoke. Clinical measurements were available at baseline, at membrane removal and at the 1‐year follow‐up. The oral hygiene of both groups was good, but smokers had significantly higher full mouth plaque scores. No significant differences were observed between smokers and non‐smokers in terms of % of tissue gained at membrane removal. At the 1‐year follow up, however, smokers gained significantly less probing attachment level than non‐smokers (2.1 ± 1.2 mm compared with 5.2 ± 1.9 mm). A multivariate model, correcting for the oral hygiene level of the patients and the depth of the infrabony component, indicated that smoking was in itself a significant factor in determining the clinical outcome. A risk‐assessment analysis indicated that smokers had a significantly greater risk than non‐smokers to display a reduced probing attachment level gain following GTR. It is concluded that cigarette smoking is associated with a reduced healing response after GTR treatment, and may be responsible, at least in part, for the observed results.
The relationship of β‐glucuronidase activity in crevicular fluid to probing attachment loss in patients with adult periodontitis
Authors: Lamster Ira B. , Holmes Lyndal G. , Williams Gross Karen B. , Oshrain Richard L. , Cohen D. Walter , Rose Louis F. , Peters Lourdes M. , Pope Mark R.
Published: August 2010

Abstract Analysis of gingival crevicular fluid (GCF) offers a non‐invasive means of studying the host response in periodontal disease, and may provide an early‐indication of the patient at risk for active periodontitis. A number of host markers have been studied for their relationship to disease activity (probing attachment loss or PAL). GCF levels of the acid glycohydrolase β‐glucuronidase (βG), a marker of primary granule release from polymorphonuclear leukocytes (PMN), have been shown to identify patients with periodontitis at risk for additional PAL. In this multicenter trial, we evaluated (a) the short‐term effect of conservative periodontal therapy on βG activity in GCF, and (b) the relationship of persistently elevated βG activity to PAL in patients who were monitored for 6 months. The study population included a total of 140 patients with chronic adult periodontitis. 130 patients were on a regular recall schedule, and 10 were previously untreated. After collection of baseline clinical data at all sites, and analysis of βG in GCF from one site (mesiobuccal) per tooth, the patients received a scaling and prophylaxis. Two weeks later patients were seen for collection of GCF. If elevated enzyme activity was found at 2 weeks, the patients were seen at 3 months for a clinical exam and GCF collection. Clinical parameters were collected from all patients at 6 months. Therapy tended to reduce βG activity in GCF. Allowing ± 20 units of βG activity for sampling and assay variability. 2 weeks after therapy, 24.5% of patients had lower βG levels, 8.6% of patients had higher levels and 66.9% of patients did not change. Using patients as the unit of observation, algorithms were created relating persistently elevated βG activity to PAL. The algorithms were based on analysis of βG data at baseline, 2 weeks and 3 months, or baseline and 2 weeks. For the algorithms using βG data collected at 3 examinations, the risk ratio ranged from 7X to 14X, total predictive value ranged from 83% to 88%, sensitivity ranged from 65% to 77%, specificity ranged from 85% to 89% and the K statistic ranged from 0.41 to 0.44. If only the baseline and 2‐week GCF data was used, accuracy decreased slightly, but a strong association between elevated βG activity and PAL remained (i.e., risk ratio of 6x to 10X). These data support our earlier findings that elevated levels of BG in GCF, indicative of increased PMN activity in the crevice, is associated with PAL in patients with chronic adult periodontitis. The role of the PMN in destruction of periodontal tissue may relate to release of lysosomal enzymes, and generation of reactive oxygen metabolites in the crevicular environment.
Mandibular and maxillary furcation tunnel preparations – literature review and a case report
Authors: Rüdiger Stefan G.
Published: August 2010

Aim: The objective of this literature review and subsequent case report is to discuss and illustrate the tunnel preparation procedure as a treatment alternative for furcation‐involved molars.

Review of the literature: Furcation tunnel preparation, i.e., the creation of access for plaque control between periodontally diseased roots, has not been discussed in the literature as comprehensively as root resective therapy, though success rates appear to fall within the same range. A short root trunk and a wide furcation entrance diameter are prerequisites for the indication of the tunnel preparation procedure. Although accessory canals in the furcation area are frequent findings on extracted teeth, endodontic complications have not been reported to be major complications after tunnel preparation. Caries developed at tunneled teeth even under proper maintenance, but did not necessarily lead to the loss of an affected tooth.

Case report: In the case presented to illustrate the indication for the tunnel preparation procedure, periodontal disease was almost entirely restricted to the furcation sites of molar teeth. Affected teeth were either extracted or left intact and subjected to tunneling procedures. Periodontal health could be established and maintained at both single and double tunnels over a period of 2 years of periodontal supportive therapy.
Local delivery of chlorhexidine gluconate (PerioChipTM) in periodontal maintenance patients
Authors: Heasman P. A. , Heasman L. , Stacey F. , McCracken G. I.
Published: August 2010

Aim: The aim of this randomised, split‐mouth, single‐blind study was to determine the efficacy of controlled‐release delivery of chlorhexidine gluconate 2.5 mg (PerioChipTM) in patients with residual bleeding pockets (>5 mm) at least 3 months following oral hygiene and root debridement phase therapy.

Material and Methods: 26 patients (non‐smokers) were screened and potential study sites identified. Clinical parameters recorded at baseline and all subsequent visits were plaque index (PI), pocket probing depth (PPD), bleeding index (BI) and clinical attachment level (CAL). All study sites were debrided using ultrasonic instrumentation. PerioChips (PC) were placed in the selected sites of two quadrants (left or right) whilst identified sites in the remaining quadrants were left without adjunctive antimicrobial treatment. Clinical measurements were made at follow‐up visits after 1, 3 and 6 months. Mean changes from baseline in PPD, BI and CAL were calculated with the patient as the experimental unit and comparability between the treatments was determined using t‐tests.

Results: At baseline there were no significant differences between PC and control sites for mean PI, PD, BI or CAL. The mean (SE) reductions in PPD for PC and control treatments were: 0.47 (0.1), 0.46 (0.1); 0.76 (0.1), 0.55 (0.1); 0.78 (0.1), 0.45 (0.1) for months 1, 3 and 6 respectively. Only at month 6 did the difference between treatments approach statistical significance (p=0.06). Mean (SE) reductions in CAL over the same periods were: 0.17 (0.1), 0.04 (0.08); 0.38 (0.1), 0.21 (0.1); 0.43 (0.1), 0.15 (0.09) p=0.048. Mean (SE) reduction in BI between PC and control treatments only reached statistical significance at 6 months: 1.08 (0.1), 0.59 (0.1) p=0.05.

Conclusion: These data suggest that PerioChipTM is beneficial for patients on maintenance therapy although the benefit is not apparent until 6 months after placement.
Herpesviruses in HIV‐periodontitis
Authors: Contreras Adolfo , Mardirossian Armen , Slots Jørgen
Published: August 2010

Background/aims: Human herpesvirus‐associated diseases exhibit elevated morbidity and mortality in patients infected with human immunodeficiency virus (HIV).This study aimed to investigate the occurrence of herpesviruses in HIV‐periodontitis.

Method: Gingival biopsies from periodontitis lesions of 21 HIV‐patients and 14 non HIV‐patients were studied. Nested‐polymerase chain reaction methods were employed to detect human cytomegalovirus, Epstein‐Barr virus type 1 and 2 (EBV‐1, EBV‐2), herpes simplex virus, human herpes virus (HHV)‐6, HHV‐7 and HHV‐8.

Results: Gingival biopsies from HIV‐periodontitis lesions showed on average 4.0 herpesvirus species and gingival biopsies from HIV periodontitis lesions of non‐HIV patients revealed an average of 1.9 herpesvirus species (p<0.001). Occurrence of 4 to 6 different herpesviruses was more common in HIV‐ than in non HIV‐gingival biopsies (71% vs. 7%) (p<0.001). EVB‐2 was detected in 12 (57%) biopsies from HIV‐periodontitis but was absent in non HIV‐periodontitis biopsies (p=0.002). HHV‐6 also occurred in significantly higher frequency in HIV‐periodontitis (71%) than in non HIV‐periodontitis (21%) (p=0.01). HHV‐8 was detected only in biopsies from HIV‐periodontitis lesions..

Conclusion: HIV‐periodontitis seems to be associated with elevated occurrence of EBV‐2, HHV‐6 and herpesvirus co‐infections compared to periodontitis in non‐HIV‐patients. The periodontopathic significance of herpesviruses in HIV‐periodontitis constitutes a research topic of considerable interest.
A clinical study to compare the efficacy of 2 electric toothbrushes in plaque removal
Authors: Dörfer Christof E. , Berbig Bernadette , Von Bethlenfalvy Eric R. , Staehle Hans Jörg , Pioch Thomas
Published: August 2010

Objectives: To compare the cleaning efficacy of a powered toothbrush with 3‐dimensional brush head action (Braun Oral‐B 3D Plaque Remover D15) and a high‐speed “microtation” brush with an additional “microbrush®‐clip” (Rowenta Dentasonic MH921S).

Material and Methods: 82 healthy subjects took part in the study. After a familiarization period of 8 days, the subjects abstained from all oral hygiene procedures for 48 h. After plaque was scored, the subjects brushed their teeth under supervision with the two brushes according to a split‐mouth design. Immediately after brushing, subjects completed a questionnaire and plaque was scored again.

Results: The overall plaque scores were found to be significantly reduced from 3.05±0.60 to 1.96±0.63 by the D15 and from 3.02±0.58 to 2.24±0.64 by the Dentasonic (p<0.05). The proximal surface plaque scores were reduced from 3.20±0.63 to 2.17±0.69 by the D15 and from 3.17±0.60 to 2.44±0.69 by the Dentasonic. The relative plaque reduction was overall 36.6±12.2% for the D15 compared to 26.1±13.5% for the Dentasonic and at proximal surfaces, 33.1±12.3% and 23.2±13.0%, respectively. 75% of the subjects stated that they would prefer to keep the D15.

Conclusions: Both brushes were able to remove a significant amount of plaque, but the D15 was significantly more effective compared to the Dentasonic. The additional “microbrush®‐clip” for the proximal embrasures failed to improve plaque removal from these tooth surfaces, compared to the D15 alone.
Periodontal disease among indigenous people in the Amazon rain forest
Authors: Ronderos Mauricio , Pihlstrom Bruce L. , Hodges James S.
Published: August 2010

Background: People are not all equally susceptible to periodontitis. To understand the epidemiology and natural history of this disease, it is important to study populations with varying genetic backgrounds and environmental exposures.

Aim: Characterize the periodontal condition of a sample of indigenous adults in a remote region of the Amazon rain forest and determine the association of periodontal disease with various demographic, behavioral and environmental factors.

Methods: A cross‐sectional evaluation of 244 subjects aged 20–70 years was conducted. Pocket depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), plaque and calculus were assessed for the Ramfjord index teeth.

Results: These people had high levels of plaque, calculus and BOP. The mean PD was rather shallow (2.45 mm in 20–29 year‐olds to 2.73 mm in 50+ year‐olds) and did not increase significantly with age. Mean CAL (0.57 mm in 20–29 year‐olds and 2.26 mm in 50+ year‐olds) and mean location of the free gingival margin in relation to the cemento‐enamel junction changed significantly with age (p<0.0001). Multivariate analysis revealed that increasing age, bleeding on probing and calculus scores were positively associated with mean CAL (p<0.01). Sex, ethnicity, level of modern acculturation, use of coca or tobacco paste, frequency of dental visits and plaque were not associated with mean CAL.

Conclusions: Periodontal disease in these people was mainly associated with gingival recession rather than deep pockets. Most people had clinical attachment loss but despite poor oral hygiene and extensive gingival inflammation, they did not have very severe periodontal destruction.
Comparative investigations of the desensitising efficacy of a new dentifrice
Authors: Sowinski J. , Ayad F. , Petrone M. , DeVizio W. , Volpe A. , Ellwood R. , Davies R.
Published: August 2010

Objectives: In two clinical trials of 8 weeks duration, the ability of a new dentifrice, containing potassium nitrate, stannous fluoride and sodium fluoride to reduce dentine hypersensitivity was compared with either a non‐desensitising fluoride dentifrice or a commercially available desensitising dentifrice (Sensodyne F) to reduce dentine hypersensitivity.

Method: In both studies, the participants had to have at least two sensitive root surfaces. Subjects were stratified by baseline tactile and air blast sensitivity scores and the number of sensitive teeth and randomly allocated to 2 balanced groups. In the first study (N=81) the new dentifrice was compared with a fluoride dentifrice and in the second study (N=105) with Sensodyne F. Participants were requested to brush with their assigned dentifrice twice a day for one minute. At 4 and 8 weeks the sensitive teeth were again examined and their tactile and air blast sensitivity scores recorded.

Results: In study 1, the group using the new dentifrice tolerated greater pressure after 4 (34.9 g) and 8 weeks (38.4 g) than the group using the fluoride dentifrice (22.9 g and 19.0 g, respectively). These differences were statistically significant (p<0.001). At 4 and 8 weeks, the mean air blast scores for the group using the new dentifrice (1.39 and 0.83) were lower than for the group using fluoride dentifrice (1.78 and 1.76) and were significantly different at 8 weeks (p<0.001). In study 2 the group using the new dentifrice tolerated greater pressure after 4 (40.5 g) and 8 weeks (43.7 g) than the group using Sensodyne F (27.8 g and 33.2 g, respectively). These differences were statistically significant (p<0.001). At 4 and 8 weeks, the mean air blast scores for the group using the new dentifrice (1.10 and 0.67) were significantly lower than the group using Sensodyne F (1.90 and 1.57) (p<0.001).

Conclusions: These studies demonstrate that the new dentifrice, containing potassium nitrate, stannous fluoride and sodium fluoride is significantly better at reducing dentine hypersensitivity than both the dentifrice containing sodium fluoride and the one containing potassium chloride, triclosan and sodium fluoride (Sensodyne F).
Tooth substance loss resulting from mechanical, sonic and ultrasonic root instrumentation assessed by liquid scintillation
Authors: Schmidlin P. R. , Beuchat M. , Busslinger A. , Lehmann B. , Lutz F.
Published: August 2010

Aims: This study investigated the loss of tooth substance (μg) by means of liquid scintillation in combination with profilometric and SEM analyses in order to evaluate the roughness and morphological changes of the root surface before and after instrumentation.

Method: 40 polished and irradiated bovine root surfaces were scaled in vitro while covered with 50 ml destilled water using a sonic prototype (Periosonic® 1/2), a magnetostrictive ultrasonic (Cavitron® with Slimline® inserts) scaler and a hand curette. Pressures were applied for the Periosonic, Cavitron and hand curette at 500, 500 and 30 g respectively, for 30‐s intervals, up to 120 s. Loss of apatite (μg) was determined from the decays/min (32P) of the water samples using the radiochemical method of liquid scintilation. Replicas were made of the specimens for SEM and profilometric analyses.

Results: The least substance loss was noted significantly (p<0.01) at all time intervals after Slimline, followed by the fine sonic prototype Periosonic 2, then the Periosonic 1 and finally the hand curette. In contrast, profilometric and SEM analyses revealed the smoothest root surfaces after the hand curette, whereas Cavitron produced a less smooth surface.

Conclusion: It can be concluded that this method can reveal very precisely small quantities of substance lost and, in combination with SEM analysis and microroughness measurements, be of considerable value in evaluating the aggressiveness and efficacy of periodontal instruments.
The significance of prior mechanical therapy for changes of periodontal status achieved by local delivery of a doxycyclinehyclate containing gel
Authors: Wolinsky Lawrence E. , Camargo Paulo M. , Polson Alan , Ryder Mark , Garrett Steven
Published: August 2010

Aim: The purpose of this retrospective analysis was to examine what effect, if any, the time elapsed between an individual’s last episode of scaling and root planing and subsequent treatment with a sustained‐release doxycycline hyclate gel (DH) alone or scaling and root planing alone (SRP) would have upon adult periodontitis.

Methods: A total of 207 subjects were included in the DH group and 210 patients in the SRP group. Periodontitis was defined as those sites which presented with pocket depths 5 mm and exhibited bleeding upon probing. In both DH and SRP groups, 3 sub‐groups of subjects were identified according to their last episode of scaling and root planing prior to the study baseline: within 2 to 6 months, >6 but 12 months, and one or more times in their life but not within the last 12 months. Each study site was treated twice over a 9‐month study period, once at baseline and again at 4 months. Data from the study sites at 4, 6, and 9 months were then evaluated for changes in probing depth, clinical attachment level, and bleeding upon probing.

Results: At the 9‐month evaluation, all sub‐groups in the DH and SRP treatment arms presented with improvement in the measured clinical parameters, as compared to baseline. No significant differences were observed in the measured periodontal indices among the study sites between the three sub‐groups for either treatment.

Conclusions: It is concluded that the time interval since the last episode of scaling and root planing had no observable effect on the results achieved when treating periodontitis sites with locally delivered doxycycline hyclate alone or scaling and root planing alone. The treatment of periodontitis sites with locally delivered doxycycline hyclate resulted in clinical improvement comparable to scaling and root planing irrespective of the patient’s prophylaxis frequency.
Sulfate‐reducing bacteria in relation with other potential periodontal pathogens
Authors: Langendijk‐Genevaux P. S. , Grimm W.‐D. , Van Der Hoeven J. S.
Published: August 2010

Background, aims: Oral sulfate‐reducing bacteria are involved in several clinical categories of periodontitis. The aim of this cross‐sectional study was to compare the presence of sulfate‐reducing bacteria (SRB) with other putative pathogens including spirochetes, Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Porphyromonas gingivalis, and Treponema denticola in periodontal lesions.

Method: Periodontal SRB were detected by enrichment culture and compared with a microscopic spirochete count (n=168). Species‐specific oligonucleotide probes directed against the 16S rRNA were employed to determine the presence of A. actinomycetemcomitans, P. gingivalis, B. forsythus, and T. denticola (n=55).

Results: A significant positive correlation was observed between the presence of SRB and the proportions of spirochetes in subgingival plaque, although the 2 bacterial groups also occurred separately. SRB tended to be negatively correlated with the presence of A. actinomycetemcomitans. In contrast, all pockets with SRB harbored either T. denticola, or both T. denticola and B. forsythus (12/14) before therapy. Interestingly, the combination of SRB with P. gingivalis occurred in 32% of the periodontal pockets before treatment. After initial periodontal therapy, the prevalence of this combination was reduced to 2% of the sites, and to 25% of the sites in recall patients.

Conclusion: The presence of SRB was positively correlated with T. denticola, B. forsythus, and P. gingivalis in periodontal lesions. These suspected pathogens form a complex strongly associated with destructive periodontitis.
Cyclooxygenase‐2 Gene−765single nucleotide polymorphism as a protective factor against periodontitis in Taiwanese
Authors: Ho Ya‐Ping , Lin Ying‐Chu , Yang Yi‐Hsin , Ho Kun‐Yen , Wu Yi‐Min , Tsai Chi‐Cheng
Published: August 2010

Aim:Prostaglandin E2(PGE2) is considered to be an important mediator of tissue destruction in periodontitis. The cyclooxygenase (COX) catalyses the production of PGs. COX‐2, which is induced in an inflammatory response, is responsible for PGs synthesis at sites of inflammation. A single nucleotide polymorphism of COX‐2−765has been shown to alter the expression of the COX‐2 gene. The purpose of the present study was to evaluate the association of the COX‐2−765polymorphism and susceptibility to periodontitis in Taiwanese.

Material and Methods:Eighty‐five cases of aggressive periodontitis (AgP), 343 cases of chronic periodontitis (CP) and 153 cases of healthy controls (HC) were recruited for the study. Genotypes of COX‐2−765were determined by polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP). The distribution of genotypes among groups was compared by logistic regression analyses. The risk for periodontitis associated with genotypes was calculated as the odds ratio (OR).

Results:The prevalence of the GC and CC genotypes was significantly lower in AgP (5%) and in CP (29%) compared with the HC (42%). The ORs for carriage of the −765C allele (GC+CCversusGG) in AgP and CP were 0.068 (95% CI=0.020–0.173,p<0.0001) and 0.571 (95% CI=0.385–0.849,p=0.006), respectively. After adjustment for age, gender and smoking status, the OR was 0.071 (95% CI=0.017–0.219) and 0.552 (95% CI=0.367–0.829) for AgP and CP, respectively.

Conclusions:The results of the study suggest that the −765G to C polymorphism of the COX‐2 gene is associated with a decreased risk for periodontitis in Taiwanese, especially in AgP. However, the biological meaning needs further investigation.
The use of rodent models to investigate host–bacteria interactions related to periodontal diseases
Authors: Graves Dana T. , Fine Daniel , Teng Yen‐Tung A. , Van Dyke Thomas E. , Hajishengallis George
Published: August 2010

Even though animal models have limitations, they are often superior to in vitro or clinical studies in addressing mechanistic questions and serve as an essential link between hypotheses and human patients. Periodontal disease can be viewed as a process that involves four major stages: bacterial colonization, invasion, induction of a destructive host response in connective tissue and a repair process that reduces the extent of tissue breakdown. Animal studies should be evaluated in terms of their capacity to test specific hypotheses rather than their fidelity to all aspects of periodontal disease initiation and progression. Thus, each of the models described below can be adapted to test discrete components of these four major steps, but not all of them. This review describes five different animal models that are appropriate for examining components of host–bacteria interactions that can lead to breakdown of hard and soft connective tissue or conditions that limit its repair as follows: the mouse calvarial model, murine oral gavage models with or without adoptive transfer of human lymphocytes, rat ligature model and rat Aggregatibacter actinomycetemcomitans feeding model.
Clinical subgingival calculus detection with a smart ultrasonic device: a pilot study
Authors: Meissner Grit , Oehme Bernd , Strackeljan Jens , Kocher Thomas
Published: August 2010

Aim: We have recently tested a surface detection system based on a conventional dental ultrasonic scaler in vitro. The aim of the present study was to investigate sensitivity and the specificity of the detection device in vivo.

Material and Methods: Subgingival buccal surfaces of 63 arbitrarily selected periodontally compromised teeth were scanned intra‐orally, while the supragingival positions of the insert, along with the corresponding signals of the detection system, were saved as separate files. After extraction, the surface detection results were evaluated by re‐positioning the inserts' position on the tooth in vitro and comparing the detection results with visual findings.

Results: On the scanned tooth surfaces, there were 44 calculus spots, which covered 22.3% of all scanned surfaces (prevalence). The calculus‐free surface was divided into “spots” mathematically. The device correctly classified 40 calculus and 125 cementum spots, whereas four calculus and 28 cementum spots were classified incorrectly. Calculus and cementum were discriminated with a sensitivity of 91% and a specificity of 82%. The positive and negative predictive values were 0.59 and 0.97.

Conclusion: The surface detection device was able to clinically differentiate cementum and calculus in vivo. Therefore, this method may support the decision of whether continued subgingival scaling could damage the cementum.
C‐reactive protein associated with periodontitis in a Thai population
Authors: Pitiphat Waranuch , Savetsilp Warangrat , Wara‐Aswapati Nawarat
Published: August 2010

Aim: C‐reactive protein (CRP) has been implicated as a possible mediator of the association between periodontitis and several systemic diseases. Previous studies suggest an association between increased CRP levels and periodontitis predominantly in Caucasians. This study evaluated the associations of chronic periodontitis and Porphyromonas gingivalis with CRP in systemically healthy Thai adults.

Material and Methods: Serum high‐sensitivity CRP was measured in 21 generalized periodontitis, 62 localized periodontitis, and 38 periodontally healthy control subjects. P. gingivalis in subgingival plaque samples was analyzed by polymerase chain reaction.

Results: Overall, these subjects had a median CRP level lower than that reported in the western populations. Subjects with generalized periodontitis and localized periodontitis had higher median CRP levels than controls (1.78 and 0.65 mg/l versus 0.25 mg/l, p<0.001). Multivariate linear regression showed that log CRP levels were increased in subjects with generalized periodontitis (p<0.01) and localized periodontitis (p=0.03) compared with the controls, adjusted for age, body mass index and smoking. Presence of P. gingivalis was also independently associated with elevated log CRP levels (p<0.001).

Conclusion: Periodontitis and subgingival P. gingivalis are associated with increased CRP levels. These findings suggest that periodontal infection may contribute to systemic inflammatory burden in otherwise healthy individuals.
Tooth loss after active periodontal therapy. 1: patient‐related factors for risk, prognosis, and quality of outcome
Authors: Eickholz Peter , Kaltschmitt Jens , Berbig Janet , Reitmeir Peter , Pretzl Bernadette
Published: August 2010

Objectives: Assessment of patient‐related factors contributing (1) to tooth loss and (2) to the quality of treatment outcome 10 years after initiation of anti‐infective therapy.

Material and Methods: All patients who had received active periodontal treatment 10 years ago by the same examiner were recruited consecutively until a total of 100 patients were re‐examined. Re‐examination was performed by a second examiner and included clinical examination, test for interleukin‐1 (IL‐1) polymorphism, smoking history, review of patients' files (e.g. regularity of supportive periodontal therapy: SPT). Statistical analysis included Poisson and logistic regressions.

Results: Fifty‐three patients attended SPT regularly, 59 were females, 38 were IL‐1 positive. Poisson regressions identified mean plaque index during SPT (p<0.0001), irregular attendance of SPT (p<0.0001), age (p<0.0001), initial diagnosis (p=0.0005), IL‐1 polymorphism (p=0.0007), smoking (p=0.0053), and sex (p=0.0487) as factors significantly contributing to tooth loss. Additionally, mean plaque index during SPT (p=0.011) and irregular SPT (p=0.002) were associated with a worse periodontal status 10 years after initiation of therapy.

Conclusion: The following risk factors for tooth loss were identified: ineffective oral hygiene, irregular SPT, IL‐1 polymorphism, initial diagnosis, smoking, age and sex.
Spatial patterns in the species richness of birds in the New World
Authors: Blackburn Tim M. , Gaston Kevin J.
Published: August 2010

Spatial patterns m species richness of the complete New World avifauna were analysed, using data previously employed to examine spatial trends in geographic range size This allowed variation in the patterns to be compared Species richness was highest around the equator, and decreased towards higher latitudes in both hemispheres This decrease was asymmetrical, at equivalent latitudes, richness was higher in the southern than in the northern hemisphere, although the reverse was true for a measure of endemism Controlling for latitude, species richness was higher in the west than m the east The net primary productivity of, and solar radiation received by an area were both correlated with species richness However, neither explained more variation in richness than did latitude No single mechanism developed to explain spatial patterns in species richness satisfactrily explains the patterns observed in the New World avifauna We discuss, reasons why this might be the case Finally, we point out that species richness at low latitudes is not simply a multiplication of richness at high latitudes, species found at high and low latitudes are unlikely to be ecologically equivalent Any mechanism that is proposed to explain richness patterns in New World birds will need also to account for this observation
Species richness in mammalian herbivores: patterns in the horeal zone
Authors: Danell Kjell , Lundberg Per , Niemela Pekka
Published: August 2010

Latitudinal gradients in species diversity are well established for a number of plant and animal taxa Both historical and present‐day environmental factors have been suggested to be responsible for observed pattems We tested the hypothesis that current environmental features of the environment (primary productivity and regional landscape structure) may explain the longitudinal variation in species richness of mammalian herbivores in the Holarctic boreal zone Mammalian herbivore species diversity was strongly correlated with a number of environmental variables measured We reduced the data set by a principal components analysis (PCA) and found that in the Palearctic, species richness is positively related to warm climate (high temperature sum), the number of hardwood species, and the area of boreal forest In the Nearctic, species richness increases as the length of the growing season and the number of coniferous tree species increase Thus indirect measures of primary productivity as well as tree species number may accurately predict species richness in mammalian herbivores In addition, there seems to be a strong species‐area effect at the regional level The larger and more homogeneous in terms of forest coverage a boreal section is, the more species coexist there
Position within the geographic range, relative local abundance and developmental instability
Authors: Kiflawi M. , Enquist B. J. , Jordan M. A.
Published: August 2010

Local population abundance often declines with increasing distance from the center of the species' geographic range. This pattern has been hypothesized to parallel the decline in the probability of encountering favorable niche requirements, implying that local abundance is primarily a reflection of local environmental conditions. In this study we evaluate a potential corollary of this hypothesis. We postulate that local conditions that depress abundance are also likely to perturb development. Accordingly, we predicted that spatial patterns in abundance should be mirrored by spatial patterns of developmental instability. To test this prediction we compared 38 contemporary and Pleistocene populations, belonging to 30 mollusc species. Samples were collected at a single site along the Gulf of California, differentially located in relation to the center of each species' geographic range. We identified, as boundaries to triangular bivariate distributions, a negative relationship between developmental instability and relative abundance, and a positive relationship between instability and relative distance from the center of the range. Overall, however, the observed pattern deviated from the expected in that the majority of low‐abundance peripheral populations exhibit relatively low levels of developmental instability.
Variation in the relationship between numbers of breeding pairs and woodland area for passerines in fragmented habitat
Authors: Bellamy P. E. , Rothery P. , Hinsley S. A. , Newton I.
Published: August 2010

Species may differ in the relationship between the numbers of breeding pairs present and woodland area, because the proportion of a wood that forms suitable habitat will vary with woodland size. In this paper, we examine the pattern of variation in abundance with woodland area for eight breeding bird species, and also show how this pattern varied between years. During 1990‐1997, we made annual censuses of 53–160 woods, of up to 10 ha in size, and fitted a power function to describe the relationships between numbers of breeding pairs and woodland area. Seven of the eight species, blackbird Turdus merula, dunnock Prunella modularis, wren Troglodytes troglodytes, great tit Parus major, chaffinch Fringilla coelebs, robin Erithacus rubecula and blue tit Parus caeruleus showed a pattern of proportionally higher numbers in smaller woods. Only long‐tailed tit Aegithalos caudatus occurred in proportionally higher numbers in larger woods. Blackbird and dunnock showed a trend towards lower numbers in large woods during years with low regional population levels; for these species large woods may provide sub‐optimal habitat. Great tit, blue tit, chaffinch and robin showed the opposite trend, towards lower numbers in small woods during years with low regional population levels; for these species small woods may provide sub‐optimal habitat. Wren and long‐tailed tit, which also showed large annual population fluctuations, showed no change in distribution with regional population level. In great tit and chaffinch, the distribution of pairs in any one year may have been influenced by site fidelity producing a lag in the response associated with regional population levels.
Direct and indirect effects of the introduced toad Bufo marinus (Anura: Bufonidae) on populations of native anuran larvae in Australia
Authors: Crossland Michael R.
Published: August 2010

Introduced species are frequently believed to have adverse effects on native biota and ecosystems. However, much of our knowledge of the ecological impacts of introduced species is anecdotal, and the mechanisms controlling these effects are often poorly understood. I used replicated artificial pond experiments to investigate the impact of eggs and hatchlings of the introduced toad Bufo marinus on populations of native anuran larvae (Limnodynastes ornatus and Litoria rubella) in Australia. Bufo marinus eggs and hatchlings are highly toxic to predatory native tadpoles. Under naturalistic conditions, populations of predatory L. ornatus tadpoles experienced significantly reduced survival when exposed to Bufo eggs and hatchlings. The impact of Bufo on L. ornatus survival was positively correlated with Bufo density. However, the toxic effects of Bufo on L. ornatus indirectly facilitated the survival of later‐breeding L. rubella by altering predator‐prey interactions between L. ornatus and L. rubella. Limnodynastes ornatus tadpoles are voracious predators of L. rubella eggs and hatchlings. Consequently, the negative impact of Bufo on populations of L. ornatus tadpoles reduced the intensity of predation by L. ornatus tadpoles on L. rubella eggs and hatchlings, thereby increasing L. rubella survival. The results demonstrate that B. marinus plays an important role in structuring native larval anuran communities via direct and indirect mechanisms, and that Bufo may have both negative and positive effects on populations of native anuran larvae. As far as I am aware, these are the first quantitative data to demonstrate that introduced fauna may affect populations of native biota via toxic effects.
Foraging of lynxes in a managed boreal‐alpine environment
Authors: Sunde Peter , Kvam Tor , Bolstad Jan P. , Bronndal Morten
Published: August 2010

Foraging of Eurasian lynxesLynx lynxwas studied with telemetry and snow tracking in central Norway. In all habitats and at all seasons, medium‐sized ungulates (roe deerCapreolus capreolus, reindeerRangifer tarandusand domestic sheepOvis aries)dominated the diet (81% of ingested biomass estimated from faeces). Mountain haresLepus timidusand galliform birds comprised the remainder of the diet (15% and 3%, respectively). Lynxes with different life history status did not differ in prey choice, but adult males utilised carcasses of ungulate prey considerably less (16% of the edible parts) than did females with offspring (80%) and subadults (58%.). Forest habitats in lowlands and adjacent to cultivated fields were the most favourable foraging habitats (indexed as the prey encounter rate per km lynx track) primarily owing to the presence of roe deer. Two family groups tracked in winter killed 0.2 ungulate per day. The importance of agricultural land as a foraging habitat and the dominance of livestock in the diet in remoter areas indicate that the lynx has responded to agriculture and reindeer husbandry during the past century by switching from smaff game to ungulates.
Experimental manipulation of the winter surface ice layer: the effects on a High Arctic soil microarthropod community
Authors: Coulson S. J. , Leinaas H. P. , Ims R. A. , Søvik G.
Published: August 2010

The effect of patch size on the tolerance of the soil microarthropod population to an experimentally induced environmental catastrophe, a thick surface ice layer, was studied at a High Arctic site (78°55 ‘N, 11°53’ E). Such an ice layer currently occurs infrequently; however, climate change models suggest that the occurrence of such an ice layer is likely to increase in frequency. The experimental approach was a factorial design with two patch sizes, an icing treatment and controls. A thin layer of natural ice was present even in the controls and this was treated as a covariate in the analysis. The soil microarthropod fauna at the experimental site consisted of five species of Collembola and seven species of oribatid mite. The experimental surface ice layer reduced the total number of the soil microarthropods studied by 50%; however, mortality differed between mites and Collembola and species within the two taxo‐nomic groups. Mites were very resistant and showed no significant change, Collembola more sensitive (the populations ofHypogastrura tullbergideclined by 56% andFolsomia quadrioculataby 54′% in the iced treatment plots). The thin annual surface ice layer seemed to have an additional effect onH. tullbergiand the miteLauroppia translamcllata.That such a thin ice layer could reduce survival was unexpected and could play an important role in determining the extreme patchy distribution of arctic soil animals.
The spatial scale of variability in small‐mammal populations
Authors: Bowman Jeff , Forbes Graham , Dilworth Tim
Published: August 2010

We studied small‐mammal populations across a range of spatial scales to determine which scales were relevant to demographic variability. We predicted that a scale of variability in population structure would occur at the scale of dispersal, which has previously been described as < 200 m for some small‐mammal species. Systematic live‐trapping surveys were conducted on nested grids at three scales: 1) extent = 4900 ha. grain =1000 m; 2) extent = 306 ha, grain = 250 m: and 3) extent = 31 ha. grain = 125 m. Prior to the present study, small‐mammal populations had not been systematically live‐trapped across a similar range of scales. From 1996 to 1998, surveys were conducted on a landscape intensively managed for timber, and on a reference landscape. Spatial analysis of abundance data demonstrated that small‐mammal populations (four species) exhibited positive spatial autocorrelation at distances of between 133 and 533 m depending on the species and the landscape. No higher‐order population structure was detected. Thus, within the range of scales we sampled, variability in small‐mammal abundance occurred over short distances (i.e. 133–533 m).
Fluctuations of an introduced population of Svalbard reindeer: the effects of density dependence and climatic variation
Authors: Aanes Ronny , Sæther Bernt‐Erik , Øritsland Nils Are
Published: August 2010

The relative contribution of density‐dependent and density‐independent factors on variation in the population growth rate of an introduced population Svalbard reindeer was studied by time series analysis. No significant effects of either direct or delayed density‐dependence were found. Annual variation in population growth rate was strongly negatively related to amount of precipitation during winter (i.e. high growth rates occurred when winters were dry). There was no significant relationship between the NAO‐index and the population growth rate. However, there was an interaction between population density and the climatic variables, i.e. the effect of climate was stronger at high densities. These results support the view that population fluctuations of arctic ungulates are strongly influenced by stochastic variation in climate.
On the insularity of islands
Authors: Rose Michael D. , Polis Gary A.
Published: August 2010

We propose that islands arc “less insular” than is generally perceived. This belief results, in part, from the paucity of studies on vagrant species that exploit islands but are not permanent residents with continual breeding populations. We show, via aneedotal evidence extracted from the literature and data acquired ON Gulf of California islands, that visitors to insular systems are fairly common. We delineate three types of events beyond the bounds of current biogeographical analysis that make islands less insular: I) migrants and “accidental” visitors. 2) individuals of a species whose foraging areas encompass many islands or the mainland and islands, and 3) species who “colonize” islands during opportune periods or years but become extinct during difficult times (source‐sink situations). Such events potentially significantly affect the ecology and evolution of island inhabitants by such means as increased predation and/or competition, transport of parasites and pathogens, dispersal of seeds and eggs, and genetic introgression and hybridization. Discussion of other “insular” habitats such as freshwater lakes and wildlife refuges illustrate that vagrancy events may be nearly ubiquitous. Studies addressing the frequency and ecological and evolutionary significance of vagrants are required, especially in light of recent and rapid extinctions on islands and the increasing fragmentation of habitats.