Sheila Cavalca Cortelli

Etiological analysis of initial colonization of periodontal pathogens in oral cavity.

ABSTRACT It is unclear when the initial colonization by periodontal pathogens occurs in the oral cavity. Therefore, we report here the association between specific age groups and the time when the initial colonization by periodontal pathogens occurs in the oral cavity in such groups. Findings are based on an epidemiological analysis of the prevalence of five periodontal pathogens in the oral cavities of a wide range of age populations, from newborn to elderly, who were randomly selected in a geographic region of Brazil. These periodontal pathogens include Campylobacter rectus, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Prevotella intermedia, and Tannerella forsythia and were analyzed in the bacterial samples isolated from gingival sulcus, the dorsum of the tongue, and cheek mucosa of diverse age groups, using a bacterial DNA-specific PCR method. Results indicated that there are distinct age-related groups where initial colonization by the five periodontal pathogens examined in this study can be detected and that the presence of teeth is a permissive factor for colonization by P. gingivalis, P. intermedia, and T. forsythia. Although it remains unclear exactly how or when target pathogens colonize healthy subjects, an understanding of age-related groups does provide a potentially useful tool in the early detection and prevention of periodontitis in healthy individuals.

Mechanisms of action of systemic antibiotics used in periodontal treatment and mechanisms of bacterial resistance to these drugs

Antibiotics are important adjuncts in the treatment of infectious diseases, including periodontitis. The most severe criticisms to the indiscriminate use of these drugs are their side effects and, especially, the development of bacterial resistance. The knowledge of the biological mechanisms involved with the antibiotic usage would help the medical and dental communities to overcome these two problems. Therefore, the aim of this manuscript was to review the mechanisms of action of the antibiotics most commonly used in the periodontal treatment (i.e. penicillin, tetracycline, macrolide and metronidazole) and the main mechanisms of bacterial resistance to these drugs. Antimicrobial resistance can be classified into three groups: intrinsic, mutational and acquired. Penicillin, tetracycline and erythromycin are broad-spectrum drugs, effective against gram-positive and gram-negative microorganisms. Bacterial resistance to penicillin may occur due to diminished permeability of the bacterial cell to the antibiotic; alteration of the penicillin-binding proteins, or production of β-lactamases. However, a very small proportion of the subgingival microbiota is resistant to penicillins. Bacteria become resistant to tetracyclines or macrolides by limiting their access to the cell, by altering the ribosome in order to prevent effective binding of the drug, or by producing tetracycline/macrolide-inactivating enzymes. Periodontal pathogens may become resistant to these drugs. Finally, metronidazole can be considered a prodrug in the sense that it requires metabolic activation by strict anaerobe microorganisms. Acquired resistance to this drug has rarely been reported. Due to these low rates of resistance and to its high activity against the gram-negative anaerobic bacterial species, metronidazole is a promising drug for treating periodontal infections.

Peri-Implant Diseases May Be Associated With Increased Time Loading and Generalized Periodontal Bone Loss: Preliminary Results

The aim of this study was to evaluate the prevalence of peri-implant diseases around Branemark system implants in Brazilians and the possible relationship with periodontal bone loss, systemic condition, and demographic profile. A total of 113 individuals were enrolled in this study, and they received 347 implants. The implants were clinically and radiographically examined and diagnosed as healthy implants, mucositis, or peri-implantitis. The demographic and systemic profiles of the individuals were assessed via questionnaires, and the time of loading was obtained from files. The presence of periodontal bone loss in partially edentulous patients was determined by standardized radiographic evaluation. With regard to implants, the prevalence was 60.5% (n = 210), 32% (n = 111), and 7.5% (n = 26) for healthy tissues, mucositis, and peri-implantitis, respectively. No correlation was found between peri-implant tissue conditions and socioeconomic status, body mass index, smoking status, gender, age, diabetes mellitus, osteopenia, and osteoporosis. Statistically significant positive correlations were found in implants with mucositis and peri-implantitis in relation to time of loading and with peri-implantitis in relation to periodontal bone loss in the 4 quadrants (P < .05). Presence of peri-implant diseases may be associated with the increasing time of loading and generalized periodontal bone loss.

Fluoxetine inhibits inflammatory response and bone loss in a rat model of ligature-induced periodontitis

BACKGROUND Fluoxetine, a selective serotonin reuptake inhibitor, has been found recently to possess anti-inflammatory properties. The present study investigates the effects of fluoxetine on inflammatory tissue destruction in a rat model of ligature-induced periodontal disease. METHODS Thirty male Wistar rats were randomly assigned into three groups (n = 10 animals per group): 1) control rats (without ligature); 2) rats with ligature + placebo (saline; oral gavage); and 3) rats with ligature + fluoxetine (20 mg/kg/day in saline; oral gavage). Histologic analyses were performed on the furcation region and mesial aspect of mandibular first molars of rats sacrificed at 15 days after ligature-induced periodontal disease. Reverse transcription-polymerase chain reaction and zymography were performed to analyze the mRNA expression of interleukin (IL)-1β, cyclooxygenase (COX)-2, matrix metalloproteinase (MMP)-9 and inducible nitric oxide synthase and the MMP-9 activity, respectively, in gingival tissues samples. RESULTS Compared to the ligature + placebo group, alveolar bone loss was reduced in the fluoxetine group (P <0.05), and the amount of collagen fibers in the gingival tissue was maintained. Moreover, in gingival tissue sampled 3 days after ligature attachment, fluoxetine administration reduced IL-1β and COX-2 mRNA expression. Fluoxetine downregulated MMP-9 activity, without affecting MMP-9 mRNA expression induced by ligature, compared to the ligature + placebo group (P <0.05). These data suggest that fluoxetine suppressed proinflammatory responses, as well as proteolytic enzyme activity, induced by ligature. CONCLUSION In the present study, fluoxetine suppresses the inflammatory response and protects against periodontal bone resorption and destruction of collagen fibers, suggesting that fluoxetine can constitute a promising therapeutic approach for periodontal diseases.

Periodontal risk assessment model in a sample of regular and irregular compliers under maintenance therapy: a 3-year prospective study.

BACKGROUND The purpose of this study is to investigate the association of the periodontal risk assessment (PRA) model with the recurrence of periodontitis and tooth loss during periodontal maintenance therapy (PMT). METHODS In a prospective PMT program, 75 regular complier (RC) and 89 erratic complier (EC) patients were selected. A periodontal examination and PRA were performed after active periodontal therapy and after 3 years of PMT. Risk profiles (low, moderate, or high) of participants were evaluated, and the recurrence of periodontitis and tooth loss were analyzed using univariate and multivariate analyses. RESULTS RCs showed less recurrence of periodontitis and tooth loss than ECs (P <0.05). Rates of periodontitis recurrence in RCs and ECs were 2.7% and 3.4%, respectively, for the moderate-risk profile and 6.7% and 11.2%, respectively, for the high-risk profile. During PMT, 49 teeth (0.65 ± 1.4 teeth per participant) were lost in the RC group, and 70 teeth (0.78 ± 2.1 teeth per participant) were lost in the EC group. High-risk profile participants showed more recurrence of periodontitis and lost significantly more teeth than did participants with moderate- or low-risk profiles in RC and EC groups (P <0.05). CONCLUSION The risk profile influenced the recurrence of periodontitis and tooth loss. RCs had less recurrence of periodontitis and less tooth loss. The PRA model can be useful in particularizing the risk of patients and adjusting recall intervals.

Risk variables in the association between frequency of alcohol consumption and periodontitis

OBJECTIVE Investigate the association between the frequency of alcohol consumption and periodontitis. Moreover, evaluate the influence of biological, behavioural, and social risk variables in this association. METHODS Sample was comprised by 542 subjects of both genders, 35-55 years of age, who underwent a complete periodontal examination, and was divided into four groups according to the frequency of alcohol use, based on alcohol use disorders identification test (AUDIT) and Cut-down, Annoyed, Guilty, Eye-opener (CAGE) instruments: (1) no or occasional alcohol use (NA), (2) moderate alcohol use (MA), (3) intense alcohol use (IA) and (4) alcohol dependence (DA). Associations between the occurrence of periodontitis and potential risk variables were analysed by univariate and multivariate logistic regression stratified by smoking status when appropriate. RESULTS The prevalence of periodontitis in NA, MA, IA and DA groups were 17.2%, 24.0%, 29.6% and 53%, respectively. Alcohol odds ratio (OR) estimates significantly increased with an increase in consumption frequency (DA>IA>MA>NA) and were approximately two times higher in smokers (OR = 3.43 to 7.91) compared to non-smokers (OR = 1.22 to 3.02). CONCLUSION Occurrence of periodontitis among alcohol users were high and the frequency of alcohol consumption increased the odds of periodontitis incrementally mainly in smokers.

Frequency of periodontal pathogens in equivalent peri- implant and periodontal clinical statuses

OBJECTIVES This study tested the hypotheses that there is: (1) higher bacterial frequency in peri-implantitis/periodontitis, followed by mucositis/gingivitis and peri-implant/periodontal health; (2) similar bacterial frequency between comparable peri-implant and periodontal clinical statuses. DESIGN OF STUDY The presence of Porphyromonas gingivalis, Tannerella forsythia, Campylobacter rectus, Prevotella intermedia, Treponema denticola and Aggregatibacter actinomycetemcomitans was evaluated in peri-implant (n=53) and periodontal (n=53) health; mucositis (n=50), gingivitis (n=50), peri-implantitis (n=50) and periodontitis (n=50). RESULTS The pattern of peri-implant bacterial frequency was not as expected (peri-implantitis>mucositis>health). Except for P. intermedia (p>0.05), bacterial frequency was higher in peri-implantitis than health (p<0.05). The frequency of P.gingivalis and red complex species were higher in peri-implantitis than mucositis (p<0.05). In periodontal samples, T. forsythia and T. denticola showed the expected pattern of frequency (periodontitis>gingivitis>health). The frequencies of C. rectus and T. forsythia were higher in healthy teeth/gingivitis than healthy implants/mucositis, respectively (p<0.05). The frequency of P. gingivalis and A. actinomycetemcomitans were similar between periodontitis and peri-implantitis (p>0.05) while all other species occurrences were higher in periodontitis than peri-implantitis (p<0.05). CONCLUSIONS Bacterial frequency increased from peri-implant/periodontal health to peri-implantitis/periodontitis but not from mucositis/gingivitis to peri-implantitis/periodontitis. There was a trend towards higher bacterial frequency in teeth than implants.

Progression of Periodontitis and Tooth Loss Associated with Glycemic Control in Individuals Undergoing Periodontal Maintenance Therapy: A 5-Year Follow-Up Study

BACKGROUND Prospective studies that investigated the influence of glycemic control in the progression of periodontitis and tooth loss during periodontal maintenance therapy (PMT) programs have not previously been reported. The aim of the present study is to evaluate associations between glycemic control status and progression of periodontitis and tooth loss among individuals during PMT. METHODS A total of 92 individuals, all recruited from a prospective cohort with 238 participants undergoing PMT, participated in this study. Diabetes control was assessed according to percentage of glycated hemoglobin (HbA1c). Individuals were matched for sex and smoking and were divided into three groups: 23 individuals with diabetes and poor glycemic control (PGC), 23 individuals with diabetes and good glycemic control (GGC), and 46 controls with no diabetes (NDC). Full-mouth periodontal examination, including bleeding on probing (BOP), probing depth (PD), and clinical attachment level, was performed at all PMT visits during a 5-year interval. RESULTS Progression of periodontitis and tooth loss were significantly higher among PGC compared to GGC and NDC. The final logistic model in the final examination included: 1) for the progression of periodontitis, HbA1c ≥6.5% (odds ratio [OR] = 2.9), smoking (OR = 3.7), and BOP in >30% of sites (OR = 4.1); and 2) for tooth loss, HbA1c ≥6.5% (OR = 3.1), smoking (OR = 4.1), and PD 4 to 6 mm in ≤10% of sites (OR = 3.3). CONCLUSIONS PGC individuals, especially smokers, presented with a higher progression of periodontitis and tooth loss compared to NDC and GGC individuals. This result highlights the influence of glycemic control in maintaining a good periodontal status.

Essential oils in one-stage full-mouth disinfection: double-blind, randomized clinical trial of long-term clinical, microbial and salivary effects.

AIM This randomized clinical trial evaluated the effects of an essential oils-containing mouthrinse for full-mouth disinfection. MATERIAL AND METHODS Fifty patients were assigned to receive full-mouth disinfection with either essential oils or placebo. At baseline, 2 and 6 months of treatment the primary outcomes probing depth (PD), plaque index (PlI) and modified gingival index (MGI) were monitored. Additional monitoring included bacterial presence (by polymerase chain reaction) in subgingival, saliva and tongue samples; flows, pH, total protein and alkaline phosphatase salivary levels. The following statistics were used: ANOVA, Students t-test, chi(2) and Kruskal-Wallis (p<0.05). RESULTS Mean PD>or=3.5 mm was reduced over time in both the placebo and the test groups, but there was no difference in PD reduction between groups at 2 and 6 months. At 2 and 6 months, PlI and MGI showed greater reductions in the test group than in the placebo group. Porphyromona gingivalis was not reduced in any site. At 6 months, Campylobacter rectus increased in both groups, while Tannerella forsythensis decreased subgingivally in the test group. S. sanguinis increased, except subgingivally, in the placebo group. Salivary pH and flows were not altered. Total protein reduced only in the test group. Alkaline phosphatase did not change in either group. CONCLUSIONS Essential oils for full-mouth disinfection showed clinical benefits, namely reducing plaque and gingival inflammation without altering basic salivary parameters.

Porphyromonas Gingivalis is Associated With Protease-Activated Receptor-2 Upregulation in Chronic Periodontitis

BACKGROUND We previously reported a higher expression of protease-activated receptor-2 (PAR(2)) together with higher interleukin (IL)-1α, IL-6, IL-8, and tumor necrosis factor-α levels, total proteolytic activity, Porphyromonas gingivalis (Pg) prevalence, and neutrophil-protease 3 messenger RNA (mRNA) expression in patients with chronic periodontitis compared to healthy control patients. The aim of the present study is to expand this observation by considering the site level according to the presence of Pg. METHODS Microbiologic and gingival crevicular fluid samples were collected from patients with chronic periodontitis. Pg presence was evaluated by polymerase chain reaction and PAR(2) mRNA expression was evaluated by reverse-transcription polymerase chain reaction. Total proteolytic activity in the crevicular fluid was analyzed by using a specific substrate benzoylarginine nitroanilide, and the proinflammatory mediators IL-1α, IL-6, IL-8, and tumor necrosis factor-α were analyzed by enzyme-linked immunosorbent assay. RESULTS In Pg-positive periodontal sites, the mean probing depth and clinical attachment level, the prevalence of bleeding on probing sites, and crevicular fluid volume were higher (P <0.05) compared to Pg-negative sites. In addition, with the exception of IL-8, all other inflammatory mediators were positively (P <0.05) associated with Pg presence. Pg presence was also positively associated with a higher proteolytic activity (P = 0.0037) and higher PAR(2) mRNA expression (P = 0.0271). CONCLUSIONS We conclude that in chronic periodontitis, periodontal pockets presenting Pg show an upregulation of PAR(2) gene expression, and higher proinflammatory profile associated with advanced clinical destruction, therefore suggesting that Pg plays a pivotal role on PAR(2)-mediated periodontal inflammation in humans.