Tiago Taiete

Impact of smoking on experimental gingivitis. A clinical, microbiological and immunological prospective study.

OBJECTIVE The present study assessed the effect of smoking on clinical, microbiological and immunological parameters in an experimental gingivitis model. MATERIAL AND METHODS Twenty-four healthy dental students were divided into two groups: smokers (n = 10); and nonsmokers (n = 14). Stents were used to prevent biofilm removal during brushing. Visible plaque index (VPI) and gingival bleeding index (GBI) were determined 5- on day -7 (running phase), baseline, 21 d (experimental gingivitis) and 28 d (resolution phase). Supragingival biofilm and gingival crevicular fluid were collected and assayed by checkerboard DNA-DNA hybridization and a multiplex analysis, respectively. Intragroup comparison was performed by Friedman and Dunns multiple comparison tests, whereas the Mann-Whitney U-test was applied for intergroup analyses. RESULTS Cessation of oral hygiene resulted in a significant increase in VPI, GBI and gingival crevicular fluid volume in both groups, which returned to baseline levels 7 d after oral hygiene was resumed. Smokers presented lower GBI than did nonsmokers (p < 0.05) at day 21. Smokers had higher total bacterial counts and higher proportions of red- and orange complex bacteria, as well as lower proportions of Actinomyces spp., and of purple- and yellow-complex bacteria (p < 0.05). Furthermore, the levels of key immune-regulatory cytokines, including interleukin (IL)-8, IL-17 and interferon-γ, were higher in smokers than in nonsmokers (p < 0.05). CONCLUSION Smokers and nonsmokers developed gingival inflammation after supragingival biofilm accumulation, but smokers had less bleeding, higher proportions of periodontal pathogens and distinct host-response patterns during the course of experimental gingivitis.

Salivary carriage of periodontal pathogens in generalized aggressive periodontitis families

BACKGROUND Generalized aggressive periodontitis (GAP) is a multifactorial disease that shows a specific microbial profile and a familial aggregation. AIM This study evaluated the salivary microbial profile of families with a history of GAP and compared them with healthy families. DESIGN Fifteen families with parents presenting periodontal health and 15 with parents with a history of GAP were selected. Each family had a child aged 6-12 years. Stimulated saliva was collected from all subjects, and Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), and Aggregatibacter actinomycetemcomitans (Aa) amounts were determined. RESULTS Children of GAP families showed higher detection of Aa (90%) than children of healthy families (45%) (P < 0.05). Parents with GAP showed a Pg salivary concentration statistically higher than that of healthy parents (P < 0.05).Children of GAP families, however, exhibited similar Pg concentration than healthy children (P > 0.05). Tf amounts did not differ either in parents or in children (P > 0.05) The infection risk calculation indicates that children who have one parent who is positive for Aa have 16.3 times (95% CI 3.1-87.2) more risk of being infected with Aa (P < 0.05) than children from an Aa-negative family. CONCLUSION It may be concluded that children of parents with aggressive periodontitis have higher levels and higher risk of Aa infection.

Mutacins of Streptococcus mutans.

The colonization and accumulation of Streptococcus mutans are influenced by various factors in the oral cavity, such as nutrition and hygiene conditions of the host, salivary components, cleaning power and salivary flow and characteristics related with microbial virulence factors. Among these virulence factors, the ability to synthesize glucan of adhesion, glucan-binding proteins, lactic acid and bacteriocins could modify the infection process and pathogenesis of this species in the dental biofilm. This review will describe the role of mutacins in transmission, colonization, and/or establishment of S. mutans, the major etiological agent of human dental caries. In addition, we will describe the method for detecting the production of these inhibitory substances in vitro (mutacin typing), classification and diversity of mutacins and the regulatory mechanisms related to its synthesis.

Transcriptome of Healthy Gingival Tissue from Edentulous Sites in Patients with a History of Aggressive Periodontitis

BACKGROUND This study evaluated the transcriptome of healthy gingival tissue from edentulous sites in patients with a history of generalized aggressive periodontitis (GAgP), chronic periodontitis (CP) and in patients with no history of periodontitis (H), using microarray and quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis. METHODS Healthy gingival tissue from edentulous sites was taken from GAgP (n =12), CP (n=12) and H (n=12) patients. Initially, total RNA from 4 tissues samples per group was employed in transcriptomic microarray analysis. Differential gene expression (fold-change), gene ontology (GO; biological process) and pathway analyses were performed. Genes that were differentially expressed and showing a significant role on altered pathways were validated by qRT-PCR analysis on 12 samples per group. RESULTS In total, 270 probes sets and 50 GO groups were differentially expressed (up-regulated or down-regulated) between GAgP and H. Natural killer cell receptors and other genes related to the immune system were up-regulated in GAgP, while genes with functions in neural processes and in proliferation/differentiation of keratinocytes were under-expressed. There were 220 probe sets and 75 GO groups that were differentially expressed when comparing CP and GAgP. CP was characterized by the increased expression of genes related to responses to external stimuli and an under-expression of immune system-related genes. qRT-PCR analysis confirmed the microarray results, that KIR2DL4, IL6 and SELE were highly expressed in GAgP than CP or H patients. CONCLUSION This study demonstrates differences in the transcriptome of healthy gingival tissue from edentulous sites from GAgP when compared with that of H or CP patients.

Clarithromycin as an Adjunct to One-Stage Full Mouth Ultrasonic Periodontal Debridement in Generalized Aggressive Periodontitis: a Randomized Controlled Clinical Trial

BACKGROUND The aim of the present study is to evaluate the periodontal clinical and microbiologic responses and possible adverse effects of clarithromycin (CLM) combined with periodontal mechanical therapy in the treatment of patients with generalized aggressive periodontitis. METHODS Forty patients were selected and randomly assigned into one of two groups: 1) CLM (n = 20): one-stage full-mouth ultrasonic debridement (FMUD) associated with CLM (500 mg, every 12 hours for 3 days); and 2) placebo (n = 20): FMUD associated with placebo pills. Clinical and microbiologic parameters were evaluated at baseline and 3 and 6 months postoperatively. RESULTS Both treatments presented statistically significant clinical and microbiologic improvements. However, the CLM group presented lower means of probing depth for pockets ≥7 mm at 6 months (4.0 ± 1.7 mm) compared with the placebo group (4.7 ± 1.3 mm) (P = 0.04). In addition, the CLM group also presented greater reduction of Porphyromonas gingivalis (Pg) DNA counts at 6 months (P = 0.0001). CONCLUSION Results from this study suggest both treatments are effective; however, adjunct use of CLM to FMUD leads to better reduction of deep pockets and Pg at 6 months compared with FMUD alone.