Rodrigo O. Rego

Effect of Atorvastatin in radiographic density on alveolar bone loss in wistar rats

The purpose of this study was to evaluate the effect of Atorvastatin (ATV) on alveolar bone loss induced in rats. Periodontitis was induced by ligature placement around the upper second left molar in a total of 24 male Wistar rats (± 200 g). Groups of 6 animals received via oral gavage either saline or ATV (1, 3 and 9 mg/kg) during 11 days. After this time, the animals were sacrificed and their maxillae were removed, defleshed, radiographed by Digora System®, and latter stained to be photographed using a digital camera. Data were analyzed statistically by ANOVA and Bonferroni test at 5% significance level and presented as mean ± SEM. ATV (9 mg/kg) caused a significant increase on gray tone variation of over 48% (118.3 ± 12.0 gray tones) when compared to saline (79.8 ± 6.2 gray tones), indicating greater radiographic density. These data were corroborated by macroscopic findings, where ATV (9 mg/kg) reduced alveolar bone loss by over 47% (p<0.05), when compared to the group of untreated animals (saline). In summary, ATV was able to prevent alveolar bone loss seen on a ligature-induced periodontitis model.

Obesity may increase the occurrence of spontaneous periodontal disease in Wistar rats

OBJECTIVE To evaluate the effect of body weight on the occurrence of spontaneous alveolar bone loss in Wistar rats. METHODS Twenty-eight rats were randomly divided in two groups. Control group received standardized rat chow diet and water. Test group received cafeteria (CAF) diet during 17 weeks. Diet was available for both groups ad libitum. Body weight and Lee Index were evaluated. At the end of the experimental period, rats were killed by decapitation and maxillae were defleshed with 9% sodium hypochlorite. Morphometric analysis was performed in digital standard photographs. Presence of spontaneous periodontitis was considered when mean alveolar bone loss was ≥0.51mm (75th percentile). Statistical analysis was performed with chi-square test, Mann-Whitney test and independent samples t-test (significance level P≤0.05). RESULTS After 17 weeks of exposure to standard CAF diet, a statistically significant mean difference in body weight (g±SD) (478±43 vs. 580±60) and Lee Index (3.07±0.05 vs. 3.24±0.07) was observed between control and obesity groups, respectively. Median (interquartile range) of alveolar bone loss in control group was 0.344 (0.313-0.367) and 0.491 (0.427-0.506) for buccal and palatal site, respectively. For obese group was 0.308 (0.289-0.354) and 0.549 (0.482-0.616) for buccal and palatal site, respectively. In animals submitted to CAF diet, 20 sites were classified as spontaneous periodontal disease, whereas in control animals, only 8 sites exhibited periodontal breakdown according cut-off point. A significant difference between groups was detected (P=0.009). CONCLUSIONS It may be concluded that obesity increases the occurrence of spontaneous periodontal disease in Wistar rats.

Serotypes of Aggregatibacter actinomycetemcomitans in relation to periodontal status and geographic origin of individuals-a review of the literature

Objectives: Several studies have focused on the relationship among serotype distribution, ethnical status and geographic populations, and periodontal conditions. Studies that have investigated the prevalence and the distribution of A. actinomycetemcomitans serotypes and the relation between the different serotypes of the bacterium and periodontal status were reviewed. Material and Methods: A systematic literature search for publications regarding the distribution of A. actinomycetemcomitans serotypes in subgingival samples of periodontitis patients and periodontally healthy subjects by employing polymerase chain reaction (PCR) was conducted. Results: From the 85 studies identified in the first analysis, only 12 met all inclusion and exclusion criteria. Clinical isolates from diverse geographic populations with different periodontal conditions were evaluated. Serotypes a, b and c were largely found, and serotype c was the most prevalent. They were isolated from various periodontal conditions, including aggressive periodontitis. Conclusions: The available literature suggests that serotypes a, b, and c are globally dominant, serotypes d and e are rare, and the prevalence of the most recently identified serotype fis still unknown. It is widely accepted that distribution patterns of A. actinomycetemcomitans vary among subjects of different ethnicity and geographic regions. The correlation of different serotypes with various periodontal conditions remains unclear. Key words:Aggregatibacter actinomycetemcomitans, serotypes, periodontal disease, prevalence.

Effects of Locally Administered Tiludronic Acid on Experimental Periodontitis in Rats

BACKGROUND It appears there are no studies evaluating the influence of the bisphosphonate tiludronic acid (TIL) on periodontitis. The purpose of this study is to evaluate via microtomographic, histopathologic, histometric, and immunohistochemical analyses the effects of local administration of TIL on ligature-induced periodontitis in rats. METHODS Forty-eight rats were divided into six groups: C (control), EP (experimental periodontitis), EP-Saline, EP-TIL0.1, EP-TIL0.3, and EP-TIL1. In EP, a ligature was placed around maxillary second molars. In EP-TIL0.1, EP-TIL0.3, and EP-TIL1, TIL solutions of 0.1, 0.3, and 1 mg/kg body weight, respectively, were injected into the subperiosteal palatal area adjacent to maxillary second molars every other day. EP-Saline received 0.9% NaCl solution instead. Animals were euthanized at day 11. Bone changes were evaluated by microtomographic and histometric analyses. Histopathologic analysis and immunohistochemical detection of tartrate-resistant acid phosphatase (TRAP) were also performed. Data were statistically analyzed (analysis of variance or Kruskal-Wallis, P <0.05). RESULTS Histometric and microtomographic analyses (at buccal, interproximal, and furcation sites) demonstrated that EP-TIL1 presented less alveolar bone loss (ABL) than EP (P <0.05), whereas EP-TIL0.1 and EP-TIL0.3 did not demonstrate significant differences in alveolar bone level compared to EP (P >0.05). Also, EP-TIL1 showed significantly fewer TRAP-positive multinucleated osteoclasts than EP and EP-Saline (P <0.05). CONCLUSION It can be concluded that locally administered TIL solution (1 mg/kg body weight) reduced alveolar bone loss in experimental periodontitis and the dosage of TIL may influence its anti-inflammatory and antiresorptive properties.

Enamel matrix proteins associated with GTR and bioactive glass in the treatment of class III furcation in dogs

This study investigated, both histologically and histometrically, the efficacy of enamel matrix derived proteins (EMD) associated with bioactive glass (BG) and an absorbable membrane in the treatment of class III furcation defects in mongrel dogs. After surgical defect creation and chronification, the lesions were randomly divided into three groups according to the treatment employed: Test Group 1--EMD + BG + membrane, Test Group 2--EMD + membrane and Control Group--BG + membrane. After a 90-day healing period, the dogs were sacrificed. The descriptive analysis and the histometric data showed similar results for the experimental groups in all studied parameters (MANOVA, p > 0.05). The association of Emdogain with bioglass and GTR, or with GTR only, showed similar results when compared with the ones obtained with bioglass associated with membrane in the treatment of class III furcation defects in dogs. The three modalities of treatment showed partial filling of the furcations, with bone and cementum regeneration limited to the apical portion of the defects.

Transmission of Aggregatibacter actinomycetemcomitans between Brazilian women with severe chronic periodontitis and their children

This study evaluated the transmission of Aggregatibacter actinomycetemcomitans (Aa) in women with severe chronic periodontitis and their children. Thirty women (mean age = 36.1+/-6.0 years) who were mothers of at least one child aged 7 to 16 years were enrolled. In order to investigate mother-child transmission of Aa, the children were also evaluated when their mothers were colonized by the bacterium. Subgingival plaque samples of each woman were collected from 3 sites (mean probing depth of 7.3+/-1.2 mm and mean clinical attachment level of 7.9+/-1.5 mm) and pooled in reduced transport fluid (RTF). These samples were processed, inoculated onto TSBV-agar selective medium and incubated at 37 degrees C in microaerophilic atmosphere for 5 days. Aa was identified on the basis of colony morphology, Gram staining, catalase and oxidase reactions. Aa was found in 8 out of 30 women. Therefore, 8 children from these women (mean age= 12 +/- 3.7 years) were evaluated, but Aa was found only in 2 of them. Aa strains of the two mother-child pairs were evaluated by arbitrarily-primed polymerase chain reaction (AP-PCR), although it was not found similarity between the amplitypes of each pair. No Aa transmission was found between Brazilian women with severe chronic periodontitis and their children.

Influence of Periodontal Disease on Changes of Glycated Hemoglobin Levels in Patients With Type 2 Diabetes Mellitus: A Retrospective Cohort Study

BACKGROUND Little evidence is available regarding the effects of long-term periodontal infection on diabetes mellitus (DM) control. The aim of this retrospective cohort study is to evaluate influence of periodontal status on changes of glycated hemoglobin (HbA1c) levels of patients with type 2 DM (DMt2). METHODS Eighty patients (mean age: 56.0 ± 8.9 years) with DMt2 were included. Patients were non-smokers, aged ≥40 years, and using antidiabetic drugs. Demographics, health history, and HbA1c levels were retrieved from medical charts. Probing depth and clinical attachment loss (AL) were recorded. RESULTS Patients were examined at two time points within a mean interval of 38.6 ± 6.6 months. Increase in HbA1c over time was statistically significant when severe periodontitis was diagnosed at baseline (2.32%, 95% confidence interval [CI]: 1.50% to 3.15%), in patients showing at least one tooth with ≥2 mm of AL progression (2.24%, 95% CI: 1.56% to 2.91%), in males (2.75%, 95% CI: 1.72% to 3.78%), and in those with HbA1c <6.5% at baseline (3.08%, 95% CI: 2.47% to 3.69%). After adjusting for baseline HbA1c, significant changes were still observed for severe periodontitis and progression of AL with increases of 0.85% and 0.9%, respectively. After adjusting for sex and HbA1c, AL progression was also statistically significant, with increases of 0.84%. CONCLUSIONS Periodontitis progression was associated with increase in HbA1c in patients with DMt2. Identification of these risk factors suggests that periodontal treatment may improve glycemic control of patients with DMt2 by eliminating periodontal infection.

Analysis of polymorphisms in Interleukin 10, NOS2A, and ESR2 genes in chronic and aggressive periodontitis.

The objective of this study was to investigate the association between single nucleotide polymorphisms (SNPs) in the IL10, NOS2A, and ESR2 genes and chronic periodontitis (CP) and aggressive periodontitis (AgP). Three groups of patients underwent periodontal and radiographic evaluations: CP (n = 61), AgP (n = 50), and periodontally healthy (control group=61). Genomic DNA was extracted from oral epithelial cells and used for genotyping by real-time polymerase chain reaction using TaqMan® probes. The investigated SNPs were: -1087G > A, -819C > T and -592C > A in the IL10; +2087G > A in the NOS2A, and +1730G > A in the ESR2 gene. Differences in genotype and allele frequencies of each polymorphism and some individual characteristics were analyzed using the chi-square test and multivariate logistic regression analysis. Analysis of SNPs and haplotypes in the IL10 and SNP in the ESR2 gene did not present any significant association with AgP or CP. The +2087G allele of the NOS2A gene tended to be significantly associated with periodontal disease. Patients carrying the genotype +2087GG in the NOS2A gene were genetically protected against the development of CP (p = 0.05; OR = 0.44; 95%CI = 0.20-0.95). This result showed greater significance when patients with AgP and CP were combined (total PD) (p = 0.03; OR = 0.46; 95%CI = 0.23-0.92). In conclusion, the studied Brazilian population had a significantly higher frequency of the GG genotype for the +2087 SNP in the NOS2A gene in individuals without periodontitis, although statistical significance was not maintained after multiple logistic regression.

Leukotoxicity of Aggregatibacter actinomycetemcomitans in generalized aggressive periodontitis in Brazilians and their family members

Objective The purpose of this study was to examine the leukotoxin promoter types of Aggregatibacter actinomycetemcomitans clones in subjects with generalized aggressive periodontitis (GAgP) and in their family members (FM). Material and Methods Thirty-five patients with GAgP (33.9±7.1 years), 33 of their FM (22.8±11.4 years), and 41 patients with chronic periodontitis (CP) (44.1±9.4 years) were clinically analyzed using the plaque index, gingival index, probing depth (PD), and clinical attachment level (CAL). Subgingival biofilm samples were collected from four interproximal periodontal sites (>PD and >CAL) of each patient. The presence of A. actinomycetemcomitans and its leukotoxic clone was confirmed by polymerase chain reaction (PCR). Results A. actinomycetemcomitans was observed in 23 (51.1%) GAgP patients and 16 (30.1%) CP patients. Thirty-seven (94.8%) patients showed minimally leukotoxic strains and 2 (5.1%) showed highly leukotoxic strains. In the FM group, 10 (30.3%) had aggressive periodontitis (AgP), 12 (36.3%) had CP, 11 (33.3%) were periodontally healthy or had gingivitis, and 12.2% were A. actinomycetemcomitans positive. Greater full mouth PD and CAL were observed in GAgP patients positive for the bacteria than those negative for it (p<;0.05), and the presence of A. actinomycetemcomitans positively correlated with GAgP (Odds ratio, 3.1; confidence interval, 1.4-7.0; p=0.009). Conclusions The presence of A. actinomycetemcomitans was associated with the clinical condition of GAgP, with most patients exhibiting a generalized form of the disease and minimally leukotoxic clones. Most of the relatives of GAgP patients presented either CP or AgP.

Periodontitis, edentulism and glycemic control in patients with type 2 diabetes: a cross-sectional study

Objectives To compare the glycemic control in non-smoking patients with type 2 diabetes according to their periodontal and dental status. Research design and methods This cross-sectional study investigated patients previously diagnosed with type 2 diabetes and under antidiabetic medication. Clinical data and fasting blood glucose (FBG) levels were collected from medical and dental records. Patients were divided into three groups according to dental and periodontal diagnosis: no or mild periodontitis (NO/MILD, n=96), moderate or severe periodontitis (MOD/SEV, n=74) and edentulous (n=141). FBG levels were compared between groups. Logistic regression was also applied to estimate the OR of presenting hyperglycemia. Results Edentulous patients had significantly higher FBG levels of 155.7±70.9 (mean±SD mg/dL) than those in the MOD/SEV (136.6±33.8) and the NO/MILD (123.1±36.7) groups. Differences between the latter two groups were also significant. Edentulous patients had adjusted ORs of 4.53, 4.27 and 3.95 of having FBG≥126, ≥150 and ≥180 mg/dL, respectively, in comparison with NO/MILD group. The MOD/SEV group also presented significant odds of having FBG≥126 mg/dL (OR=2.66) and ≥150 mg/dL (OR=2.45) than the NO/MILD group. Conclusions Patients in the MOD/SEV group had worse glycemic control than the ones in the NO/MILD group. However, edentulous patients presented higher glycemic levels than both dentate groups, and also presented with higher odds of having hyperglycemia.