Paola Carvajal

Clinical Attachment Loss in Chilean Adult Population: First Chilean National Dental Examination Survey

BACKGROUND Data from national surveys regarding the periodontal status of the adult population in Latin America are scarce. The aim of this study assesses the prevalence and extension of clinical attachment loss (AL) in the adult population of Chile. Age, sex, and sociodemographic and behavioral differences in the prevalence of clinical AL are also examined. METHODS A stratified, multistage probability design formula was used to separate the adult Chilean population into two age cohorts. The first group consisted of 1,092 young adults (age range: 35 to 44 years), and the second group consisted of 469 adult seniors (age range: 65 to 74 years). All subjects were examined to measure clinical AL. The research also included an evaluation, conducted through oral interviews, of social and health aspects of the subjects. Clinical AL was measured in all teeth surfaces, excluding third molars. Results were analyzed using a multivariable model and logistic regression. RESULTS A total of 93.45% of the young adults had ≥ 1 site with clinical AL >3 mm compared with 97.58% of the adult seniors, with an average of 6.51 and 15.81 missing teeth, respectively (P <0.05). The number of sites with severe clinical AL (>6 mm) was 38.65% in young adults and 69.35% in senior adults (P <0.05). Clinical AL was significantly higher in males than in females (P <0.05). The multivariate analyses identified that the main risk indicators for clinical AL >6 mm in ≥ 1 site were: age (65 to 74 years), sex (male) low education level (<or=12 years of education), and smoking (P <0.05). CONCLUSION The adult population in Chile shows a high prevalence and extension of clinical AL with age, sex, education level, and smoking as the main risk indicators of severe clinical AL in this population.

Clinical Effects of Lactobacillus rhamnosus in Non-Surgical Treatment of Chronic Periodontitis: A Randomized Placebo-Controlled Trial With 1-Year Follow-Up

BACKGROUND Probiotics are living microorganisms that provide beneficial effects for the host when administered in proper quantities. The aim of this double-masked placebo-controlled parallel-arm randomized clinical trial is to evaluate the clinical effects of a Lactobacillus rhamnosus SP1-containing probiotic sachet as an adjunct to non-surgical therapy. METHODS Twenty-eight systemically healthy volunteers with chronic periodontitis were recruited and monitored clinically at baseline and 3, 6, 9, and 12 months after therapy. Clinical parameters measured included plaque accumulation, bleeding on probing, probing depths (PDs), and clinical attachment loss. Patients received non-surgical therapy, including scaling and root planing (SRP), and were assigned randomly to a test (SRP + probiotic, n = 14) or control (SRP + placebo, n = 14) group. The intake, once a day for 3 months, of an L. rhamnosus SP1 probiotic sachet commenced after the last session of SRP. RESULTS Both test and control groups showed improvements in clinical parameters at all time points evaluated. However, the test group showed greater reductions in PD than the control. Also, at initial visits and after 1-year follow-up, the test group showed a statistically significant reduction in the number of participants with PD ≥6 mm, indicating a reduced need for surgery, in contrast to the placebo group. CONCLUSION The results of this trial indicate that oral administration of L. rhamnosus SP1 resulted in similar clinical improvements compared with SRP alone.

Interferon-γ, Interleukins-6 and -4, and Factor XIII-A as Indirect Markers of the Classical and Alternative Macrophage Activation Pathways in Chronic Periodontitis

BACKGROUND Macrophages account for 5% to 30% of the inflammatory infiltrate in periodontitis and are activated by the classic and alternative pathways. These pathways are identified by indirect markers, among which interferon (IFN)-γ and interleukin-6 (IL)-6 of the classic pathway and IL-4 of the alternative pathway have been studied widely. Recently, factor XIII-A (FXIII-A) was reported to be a good marker of alternative pathway activation. The aim of this study is to determine the macrophage activation pathways involved in chronic periodontitis (CP) by the detection of the indirect markers IFN-γ, IL-6, FXIII-A, and IL-4. METHODS Biopsies were taken from patients with CP (n = 10) and healthy individuals (n = 10) for analysis of IFN-γ, IL-6, IL-4, and FXIII-A by Western blot (WB), immunohistochemistry (IHC), and enzyme-linked immunosorbent assay (ELISA). The same biopsies of healthy and diseased gingival tissue were used, and the expressions of these markers were compared between healthy individuals and those with CP. RESULTS The presence of macrophages was detected by CD68+ immunohistochemistry and their IFN-γ, IL-6, IL-4, and FXIII-A markers by WB, IHC, and ELISA in all samples of healthy and diseased tissue. IL-6, IL-4, and FXIII-A were significantly higher in patients with CP, whereas FXIII-A was higher in healthy individuals. CONCLUSION The presence of IFN-γ, IL-6, IL-4, and FXIII-A in healthy individuals and in patients with CP suggests that macrophages may be activated by both classic and alternative pathways in health and in periodontal disease.

Prevalence, severity, and risk indicators of gingival inflammation in a multi-center study on South American adults: a cross sectional study

ABSTRACT Objectives: The aim of this study is to investigate the prevalence and severity of gingival inflammation and associated risk indicators in South American adults. Material and Methods: Multi-stage samples totaling 1,650 adults from Porto Alegre (Brazil), Tucumán (Argentina), and Santiago (Chile) were assessed. The sampling procedure consisted of a 4-stage process. Examinations were performed in mobile dental units by calibrated examiners. A multivariable logistic regression model was utilized for associating variables as indicators of gingival inflammation (GI) (Gingival Index ≥0.5). Statistical significance was set at 0.05. Results: A total of 96.5% of the adults have GI. Regarding the severity of GI, 22.5% of participants examined have mild GI, 74.0% have moderate GI, and 3.6% have severe GI. The multivariate analyses identify the main risk indicators for GI as adults with higher mean of Calculus Index (OR=18.59); with a Visible Plaque Index ≥30% (OR=14.56); living in Santiago (OR=7.17); having ≤12 years of schooling (OR=2.18), and females (OR=1.93). Conclusions: This study shows a high prevalence and severity of gingival inflammation, being the first one performed in adult populations in three cities of South America.

Differential expression of CC chemokines (CCLs) and receptors (CCRs) by human T lymphocytes in response to different Aggregatibacter actinomycetemcomitans serotypes

In Aggregatibacter actinomycetemcomitans, different serotypes have been described based on LPS antigenicity. Recently, our research group has reported a differential immunogenicity when T lymphocytes were stimulated with these different serotypes. In particular, it was demonstrated that the serotype b of A. actinomycetemcomitans has a stronger capacity to trigger Th1- and Th17-type cytokine production. Objective This study aimed to quantify the expression of different CC chemokines (CCLs) and receptors (CCRs) in T lymphocytes stimulated with the different A. actinomycetemcomitans serotypes. In addition, the expression of the transcription factors T-bet, GATA-3, RORC2, and Foxp3, master-switch genes implied in the Th1, Th2, Th17, and T-regulatory differentiation, respectively, was analysed in order to determine T-cell phenotype-specific patterns of CCL and CCR expression upon A. actinomycetemcomitans stimulation. Material and Methods Human naïve CD4+ T lymphocytes were obtained from healthy subjects and stimulated with autologous dendritic cells primed with the different A. actinomycetemcomitans serotypes. The expression levels for the chemokines CCL1, CCL2, CCL3, CCL5, CCL11, CCL17, CCL20, CCL21, CCL25, and CCL28, as well as the chemokine receptors CCR1, CCR2, CCR3, CCR4, CCR5, CCR6, CCR7, CCR8, CCR9, and CCR10 were quantified by qPCR. Similarly, the expression levels for the transcription factors T-bet, GATA-3, RORC2, and Foxp3 were quantified and correlated with the CCL and CCR expression levels. Results Higher expression levels of CCL2, CCL3, CCL5, CCL20, CCL21, CCL28, CCR1, CCR2, CCR5, CCR6, CCR7, and CCR9 were detected in T lymphocytes stimulated with the serotype b of A. actinomycetemcomitans compared with the other serotypes. In addition, these higher expression levels of CCLs and CCRs positively correlated with the increased levels of T-bet and RORC2 when T lymphocytes were stimulated with the serotype b. Conclusion A T-lymphocyte response biased towards a Th1- and Th17-pattern of CCL and CCR expression was detected under stimulation with the serotype b of A. actinomycetemcomitans.

Differential human Th22-lymphocyte response triggered by Aggregatibacter actinomycetemcomitans serotypes

OBJECTIVE In Aggregatibacter actinomycetemcomitans, different serotypes have been described based on lipopolysaccharide (LPS) antigenicity. When T lymphocytes were stimulated with these serotypes, different patterns of T-helper (Th)1 and Th17-type of immune responses were reported. Recently, two new Th phenotypes have been described and named Th9 and Th22 lymphocytes; however, their role in the pathogenesis of periodontitis remains unclear. This study aimed to investigate the potential Th9 and/or Th22 lymphocyte responses when stimulated with autologous dendritic cells infected with different A. actinomycetemcomitans serotypes. METHODS Monocyte-derived dendritic cells and naïve CD4+ T lymphocytes were obtained from healthy donors and stimulated with different serotypes of A. actinomycetemcomitans at a multiplicity of infection MOI=102 or their purified LPS (10-50ng/ml). The levels for the Th9 and Th22-associated cytokines, as well as the transcription factor master-switch genes implied in their differentiation Spi-B and AhR, were quantified by qPCR and ELISA. RESULTS When stimulated with the serotype b of A. actinomycetemcomitans, higher levels of interleukin (IL)-6 and tumor necrosis factor (TNF)-α were detected in dendritic cells, as well as higher levels of IL-22 and AhR were detected in T lymphocytes, when compared with stimulation with the other serotypes. CONCLUSIONS The serotype b of A. actinomycetemcomitans has a higher capacity of trigger Th22-type of immune response in both dendritic cells and T lymphocytes. These data allow us to suggest that, when the serotype b of A. actinomycetemcomitans is a significant part of the subgingival biofilm, the Th22 polarization might be triggered within the periodontal lesion.

Microbiological and clinical effects of probiotics and antibiotics on nonsurgical treatment of chronic periodontitis: a randomized placebo- controlled trial with 9-month follow-up

ABSTRACT Objective The aim of this double-blind, placebo-controlled and parallel- arm randomized clinical trial was to evaluate the effects of Lactobacillus rhamnosus SP1-containing probiotic sachet and azithromycin tablets as an adjunct to nonsurgical therapy in clinical parameters and in presence and levels of Tannerella forsythia, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. Material and Methods Forty-seven systemically healthy volunteers with chronic periodontitis were recruited and monitored clinically and microbiologically at baseline for 3, 6 and 9 months after therapy. Subgingival plaque samples were collected from four periodontal sites with clinical attachment level ≥1 mm, probing pocket depth ≥4 mm and bleeding on probing, one site in each quadrant. Samples were cultivated and processed using the PCR technique. Patients received nonsurgical therapy including scaling and root planing (SRP) and were randomly assigned to a probiotic (n=16), antibiotic (n = 16) or placebo (n = 15) group. L. rhamnosus SP1 was taken once a day for 3 months. Azithromycin 500mg was taken once a day for 5 days. Results All groups showed improvements in clinical and microbiological parameters at all time points evaluated. Probiotic and antibiotic groups showed greater reductions in cultivable microbiota compared with baseline. The placebo group showed greater reduction in number of subjects with P. gingivalis compared with baseline. However, there were no significant differences between groups. Conclusions The adjunctive use of L. rhamnosus SP1 sachets and azithromycin during initial therapy resulted in similar clinical and microbiological improvements compared with the placebo group.

Serotype a of Aggregatibacter actinomycetemcomitans down-regulates the increased serotype b -induced cytokine and chemokine production in dendritic cells

OBJECTIVE In Aggregatibacter actinomycetemcomitans, different serotypes have been described based on LPS antigenicity. Mixed infection with the different A. actinomycetemcomitans serotypes is frequent in periodontitis patients; accordingly, the role of this bacterial species in the pathogenesis of periodontitis may differ depending whether patients or periodontal lesions harbour one or more of the A. actinomycetemcomitans serotypes. We hypothesized that different combinations of these serotypes could be associated with distinct host responses and hence different inflammatory patterns. This investigation was aimed to assess whether the increased immuno-stimulatory potential attributed to the serotype b of A. actinomycetemcomitans on immune cells is able to be modified during co-infection with other A. actinomycetemcomitans serotypes. METHODS Dendritic cells (DCs) were obtained from healthy subjects and stimulated with the different A. actinomycetemcomitans serotypes or their purified LPS using the following stimulatory conditions: serotype a, b, or c, and the combinations a+b, a+c, b+c, or a+b+c. The cytokine, CCR, and CCL levels were quantified by qPCR and ELISA. RESULTS Higher levels of cytokines, CCRs, and CCLs were induced when DCs were stimulated with the serotype b of A. actinomycetemcomitans compared with the same cells stimulated with the other serotypes. When DCs were co-infected, these levels decreased in comparison with the serotype b-stimulation alone, in particular when the serotype a was present in the mixed infection. CONCLUSIONS The increased immuno-stimulatory potential attributed to the serotype b was modified when DCs were co-infected with other A. actinomycetemcomitans serotypes, in particular, when the serotype a was present, the DC response diminished.

Development of a self-report questionnaire designed for population-based surveillance of gingivitis in adolescents: assessment of content validity and reliability

Abstract The major infectious diseases in Chile encompass the periodontal diseases, with a combined prevalence that rises up to 90% of the population. Thus, the population-based surveillance of periodontal diseases plays a central role for assessing their prevalence and for planning, implementing, and evaluating preventive and control programs. Self-report questionnaires have been proposed for the surveillance of periodontal diseases in adult populations world-wide. Objective This study aimed to develop and assess the content validity and reliability of a cognitively adapted self-report questionnaire designed for surveillance of gingivitis in adolescents. Material and Methods Ten predetermined self-report questions evaluating early signs and symptoms of gingivitis were preliminary assessed by a panel of clinical experts. Eight questions were selected and cognitively tested in 20 adolescents aged 12 to 18 years from Santiago de Chile. The questionnaire was then conducted and answered by 178 Chilean adolescents. Internal consistency was measured using the Cronbach’s alpha and temporal stability was calculated using the Kappa-index. Results A reliable final self-report questionnaire consisting of 5 questions was obtained, with a total Cronbach’s alpha of 0.73 and a Kappa-index ranging from 0.41 to 0.77 between the different questions. Conclusions The proposed questionnaire is reliable, with an acceptable internal consistency and a temporal stability from moderate to substantial, and it is promising for estimating the prevalence of gingivitis in adolescents.