Márcio Eduardo Vieira Falabella

Detection of cytotoxin genotypes of Helicobacter pylori in stomach, saliva and dental plaque

BACKGROUND The aim of this study was to detect the presence of Helicobacter pylori and its virulent cagA genes in the oral cavity of individuals with upper gastric diseases. Sixty-two individuals (42+/-2.3 years) with dispepsy symptoms, referred for gastroscopy and who were H. pylori positive in the gastric biopsy, were recruited and separated in two groups: case group-individuals with gastric disease (n = 30); control group-individuals with no gastric disease (n = 32); saliva, dental plaque and biopsy samples were collected from all individuals. Oral and biopsy samples were analyzed by PCR using specific primers for H. pylori 16S ribosomal and cagA genes. PCR products were sequenced for DNA homology confirmation. H. pylori was detected neither in dental plaque nor in saliva in the control group. In the case group H. pylori DNA was detected in 16/30 (53.3%) saliva samples and in 11/30 (36.6%) dental plaque samples. The cagA gene was detected in 13/30 (43.3%) gastric biopsies, in 7/16 (43.8%) saliva samples, and in 3/11 (27.3%) dental plaque samples. Eighteen (60.0%) individuals in the case group were H. pylori positive both in oral and biopsy samples, and 8 (26.6%) of those were positive for cagA-H. pylori DNA. H. pylori and its virulent clone showed a higher prevalence in the oral cavity of individuals in the case group than in the control group (p < 0.05). Our results suggest that dental plaque and saliva may serve as temporary reservoir for H. pylori and its virulent cagA variant in individuals with gastric disease.

Presence of Helicobacter pylori in supragingival dental plaque of individuals with periodontal disease and upper gastric diseases

BACKGROUND Helicobacter pylori is a Gram-negative microorganism which is able to colonize the gastric mucosa and is associated with peptic ulcer, gastric carcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. Several studies have detected this bacterium in the oral cavity, suggesting it as a potential reservoir. The aim of this study was to investigate the presence of H. pylori in the oral cavity of individuals with periodontal disease and gastric diseases. METHODS 115 individuals, with mean age 49.6 (±5.8) years, were divided in 4 groups: (A) with gastric diseases and periodontal disease; (B) with gastric diseases and no periodontal disease; (C) without gastric diseases and without periodontal disease, (D) without gastric diseases and with periodontal disease. Supra and subgingival plaque samples were collected from posterior teeth of the individuals with sterile paper points, and prepared for Polymerase Chain Reaction analysis. Fishers exact test was used for detecting statistical differences between groups (p<0.05). RESULTS H. pylori was detected in supragingival plaque of 9/36 (25%) of group A, 1/31 (0.3%) of group B, 0 (0%) of group C and 3/36 (8.3%) of group D. No subgingival samples were positive for H. pylori. There was a statistically higher prevalence of H. pylori in groups A and D when compared to B and C (p<0.05). CONCLUSION H. pylori was detected in the supragingival plaque, but not in the subgingival plaque, of individuals with periodontal disease and upper gastric diseases. There was an association between the supragingival colonization of H. pylori and oral hygiene parameters such as the presence of plaque and gingival bleeding.

Effectiveness of full- and partial-mouth disinfection on halitosis in periodontal patients

To compare the effectiveness of full- and partial-mouth disinfection for halitosis control, patients were assigned to treatment with full-mouth therapy (complete scaling and root planing in one stage within 24 h) or conventional therapy in quadrants (scaling and root planing performed by quadrant over a period of 4 weeks) (n = 90 for each group). Both groups were then subdivided: half the patients scraped their tongue daily and half did not. The patients were then evaluated by halimeter, organoleptic testing, and tongue coating index. Halimeter evaluation showed greater reduction of sulfide gases after full-mouth therapy than after conventional therapy (P < 0.001). However, organoleptic testing and the tongue coating index showed no difference among the four treatment groups. There was also no difference in relation to tongue scraping. In conclusion, halimeter evaluation showed that the reduction in volatile sulfur compounds was significantly greater after full-mouth therapy than after conventional therapy. However, this difference was not observed in organoleptic evaluation.

Removal Torque and Bone Adherence to Dental Implants Surface

The primary stability is an important factor in achieving a predictable dental implant treatment. Therefore, in order to reach longitudinal success, it is necessary to achieve and to maintain the primary stability as basic pre-requirement [1,2]. The primary stability can be considered the first stabilization that is obtained immediately after implant insertion [3]. Thus, the insertion torque during implant installation may be an indicative of implant survival [4]. However, the initial stability may not be a factor that assures the osseiointegration, because it can be influenced by bone properties, surgical techniques and implant design [3]. Consequently, the measurement of the insertion torque could not be the only parameter to predict the osseointegration success rate. Thus, there are studies that evaluate the implants surface treatment to investigate what may influence the prognosis [5-7]. After the initial wound healing, some features determine the secondary stability as the biological response to the surgical trauma, the conditions of the wound healing and the material of the implant per se [8]. Therefore, there is an increase in the contact in the bone-implant interface [8]. At the same time, the presence of osteocytes in the bone remodeling in the bone-implant interface as well as the amount of sclerostin, osteoprotegerin and RANKL influence this remodeling [9]. Thus, when a traumatic surgery is performed or load is applied before the right time can lead to a tissue injury, resulting in bone resorption [9]. The design of the dental implant has evolved to improve its mechanical, functional and esthetic efficiency [3-8]. Nonetheless, the events that occur in the bone-implant interface are still in need of further investigation [6,7]. Having that in mind, studies involving implants with different surface treatments and the understanding the effects of different torques are important to a more comprehensive knowledge of this surfaces and the interaction with the bone tissue [1-8]. Thus, the aim of this study was to analyze the influence of the insertion torque applied to titanium dental implants with different surface treatment (acid and fluoride) on the bone adherence to the implant surface after removal from rabbit tibia by scanning electronic microscopy (SEM) after 40 days of implantation.

Periodontal Conditions in Human Immunodeficiency Virus-Positive Patients Under Highly Active Antiretroviral Therapy From a Metropolitan Area of Rio De Janeiro.

BACKGROUND The aim of this study is to evaluate the periodontal status and the presence of opportunistic oral lesions in human immunodeficiency virus-positive (HIV+) patients under highly active antiretroviral therapy (HAART) and their association with cluster of differentiation (CD)4+ and CD4+ nadir T-cell counts and viral load levels. METHODS Clinical periodontal parameters and the presence of opportunistic oral lesions along with records of CD4+ counts and viral load levels were evaluated in 29 individuals (16 females; mean age: 42.7 years) with previous serologic diagnosis of HIV, from the acquired immunodeficiency syndrome program of the Health Center of Duque de Caxias, Rio de Janeiro, Brazil. RESULTS All individuals presented gingivitis or periodontitis. A higher non-significant prevalence of periodontitis was found in smokers (93.8%) compared with non-smokers (76.9%). A significant weak positive correlation was observed between CD4+ counts and missing teeth (ρ = 0.380, P <0.05), CD4+ nadir and periodontal diagnosis (ρ = 0.418, P <0.005), and CD4+ nadir and moderate probing depth (PD) (ρ = 0.424, P <0.05). When only non-smokers were analyzed, a significant moderate positive association was found between viral load and moderate clinical attachment level (CAL) (ρ = 0.638, P <0.05), CD4+ nadir and diagnosis (ρ = 0.586, P <0.05), and CD4+ nadir and moderate CAL (ρ = 0.680, P <0.05). Analysis considering only smokers found no correlations between serologic parameters and demographic or clinical parameters. CONCLUSIONS The current investigation demonstrates that HIV+ individuals under HAART presents a high prevalence of mild to moderate periodontal disease. Viral load levels, CD4+ nadir, and CD4+ counts may present a weak to moderate correlation to the number of missing teeth, periodontal diagnosis, moderate PD, and moderate CAL, which may also reflect some effect of these systemic conditions on the periodontal status.