Güven Külekçi

Efficacy of Amoxicillin and Metronidazole Combination for the Management of Generalized Aggressive Periodontitis

BACKGROUND The aim of this study is to evaluate the effects of metronidazole-amoxicillin combination on clinical and microbiologic parameters in patients with generalized aggressive periodontitis. METHODS Twenty-eight patients were randomly included. The test group (n = 12) received amoxicillin-metronidazole combination and scaling and root planing; the control group (n = 16) received scaling and root planing alone. In addition to the clinical examinations, subgingival plaque samples were analyzed for total cultivable bacteria and the presence of Porphyromonas gingivalis, Tannerella forsythia (previously T. forsythensis), Treponema denticola, Prevotella intermedia, Prevotella nigrescens, Prevotella pallens, and Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans) using polymerase chain reaction. RESULTS All clinical parameters improved significantly compared to baseline (P <0.05) in both groups. There was a statistically significant reduction of pockets and clinical attachment gain in the combined group compared to the control group (P <0.05). Total counts of bacteria also decreased significantly at 3 and 6 months in both groups (P <0.05). T. denticola and T. forsythia were the most prevalent bacteria throughout the study. T. denticola showed a continuous decrease over 6 months in the test group, whereas no change was seen in the control group beyond 3 months. P. gingivalis decreased significantly at 3 months (P <0.05), whereas T. forsythia was the only pathogen decreased below detection limits by the combination therapy with a significant difference compared to the control group (P <0.05). CONCLUSIONS The results from this study suggest that combined amoxicillin and metronidazole use as an adjunct to scaling and root planing leads to better clinical healing compared to mechanical treatment alone. The polypharmaceutical approach used results in a significant and substantial decrease in T. forsythia and prevents its recolonization for 6 months, suggesting that T. forsythia may determine the long-term stability of periodontal treatment outcomes.

Oral colonization by Lactobacillus reuteri ATCC 55730 after exposure to probiotics

OBJECTIVE The aim of this study was to investigate whether Lactobacillus reuteri ATCC 55730 can be detected in the oral cavity after discontinuation of administration of a product prepared with this bacterium. MATERIALS AND METHODS The study consisted of three 2-week periods: clearance period, intervention period, and post-treatment period. Twenty-five volunteers consumed a chewable tablet of L. reuteri ATCC 55730 (10(8) cfu/tablet) during a 14-day trial period. Saliva samples were collected and cultured onto MRS agar after a clearance period of 2 weeks and then daily after a 2-week intervention period for as long as L. reuteri was found. Lactobacillus reuteri colonies were analysed in saliva samples. The analysis was performed using selective media for L. reuteri followed by confirmation using the specific detection of reuterin produced by L. reuteri. RESULTS The number of L. reuteri carriers decreased gradually, and after 1 week only 8% of the subjects harboured the bacterium. After 5 weeks, L. reuteri was not detected in any of the subjects. CONCLUSION Consuming L. reuteri for 2 weeks does not seem to be sufficient for permanent colonization of L. reuteri in the oral cavity.

Effects of Two Fluoride Varnishes and One Fluoride/Chlorhexidine Varnish on Streptococcus mutans and Streptococcus sobrinus Biofilm Formation in Vitro

Aims: The aim of this study was to evaluate and to compare the effect of two fluoride varnishes and one fluoride/chlorhexidine varnish on Streptococcus mutans and Streptococcus sobrinus biofilm formation, in vitro. Study design: Standard acrylic discs were prepared and divided into groups based on the varnish applied to the disc surface: Fluor Protector, Bifluoride 12, and Fluor Protector + Cervitec (1:1). Untreated discs served as controls. In the study groups, biofilms of S. mutans and S. sobrinus were formed over 24 h, 48 h, and 5 days. The fluoride concentrations in the monospecies biofilms and viable counts of S. mutans and S. sobrinus were investigated. Results: In all study groups, a statistically significant increase in the viable number of S. mutans and S. sobrinus cells was observed between 24 h and 5 days. In both monospecies biofilms, the greatest antibacterial efficacy was detected in the Fluor Protector and Fluor Protector + Cervitec groups at 24 h. For all groups, the amount of fluoride released was highest during the first 24 h, followed by a significant decrease over the next 4 days. A negative correlation was detected between fluoride concentration and antibacterial effect in those groups with biofilms containing both species. Despite the release of high levels of fluoride, the greatest number of viable S. mutans and S. sobrinus cells was detected in the Bifluoride 12 group. Statistics: The data were analyzed using GraphPad Prism software (ver. 3). Conclusions: The Fluor Protector + Cervitec varnish exerted prolonged antibacterial effects on S. mutans and S. sobrinus biofilms compared to the other varnishes tested.

Salivary detection of periodontopathic bacteria and periodontal health status in dental students.

OBJECTIVE Saliva may become a potential source of contamination through vertical and horizontal transmissions as well as cross-infections. This study aims to use saliva as a screening tool to detect putative periodontal pathogens in a young population with fairly good oral hygiene. MATERIALS AND METHODS Stimulated saliva samples were obtained from 134 dental students (20.5+/-1 years, range 18-22 years). Among those, 77 subjects also completed a periodontal examination including attachment loss, modified dental, gingival and plaque indices (AL, mDI, GI and PI). The test bacteria were identified using a 16S rRNA-based PCR detection method. RESULTS One or more of the test bacteria was found in 67% of the subjects. Prevotella nigrescens was detected as single bacterium in 16% of the subjects followed by Treponema denticola (4%), Porphyromonas gingivalis (2%), Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans (1%) and Tannerella forsythia (1%). Two or more pathogens were detected in 42% of the subjects. Clinical examination revealed health with no attachment loss (AL) in 84% of the students. In no AL group, 38% of the students were pathogen free while this was 25% for students in localized AL group (p>0.05). There was a statistically significant association between the detection of salivary periodontal pathogen in general and higher PI (p=0.018) and GI (p=0.043). CONCLUSION Within the limits of this study, it is possible to detect all six periodontal pathogens in the saliva of dental students. Although a correlation can be observed between the presence of salivary periodontal pathogen and clinical signs of inflammation such as plaque accumulation and gingival bleeding, detection of specific bacteria in saliva is not related to the presence of localized AL based on the presented study population.

16S rRNA based microarray analysis of ten periodontal bacteria in patients with different forms of periodontitis.

DNA microarray analysis is a computer based technology, that a reverse capture, which targets 10 periodontal bacteria (ParoCheck) is available for rapid semi-quantitative determination. The aim of this three-year retrospective study was to display the microarray analysis results for the subgingival biofilm samples taken from patient cases diagnosed with different forms of periodontitis. A total of 84 patients with generalized aggressive periodontitis (GAP,n:29), generalized chronic periodontitis (GCP, n:25), peri-implantitis (PI,n:14), localized aggressive periodontitis (LAP,n:8) and refractory chronic periodontitis (RP,n:8) were consecutively selected from the archives of the Oral Microbiological Diagnostic Laboratory. The subgingival biofilm samples were analyzed by the microarray-based identification of 10 selected species. All the tested species were detected in the samples. The red complex bacteria were the most prevalent with very high levels in all groups. Fusobacterium nucleatum was detected in all samples at high levels. The green and blue complex bacteria were less prevalent compared with red and orange complex, except Aggregatibacter actinomycetemcomitas was detected in all LAP group. Positive correlations were found within all the red complex bacteria and between red and orange complex bacteria especially in GCP and GAP groups. Parocheck enables to monitoring of periodontal pathogens in all forms of periodontal disease and can be alternative to other guiding and reliable microbiologic tests.

Relationship between oral anaerobic bacteria and otitis media with effusion.

Objective: In this study hypothesing the translocation of oral bacteria from oropharynx into the middle ear cavity may be involved in the pathogenesis of otitis media with effusion (OME), we aimed to investigate the presence and similarity of Fusobacterium nucleatum and Treponema denticola in saliva, nasopharyngeal secretion and the middle ear effusion samples from the children with OME. Methods: Totally 20 children with OME undergoing myringotomy and ventilation tube placement were attended. Stimulated saliva samples were collected after otorhinolaryngological and oral examinations were done. The middle ear effusion and nasopharyngeal secretions were collected during the operations. The presence of F. nucleatum and T. denticola were detected using 16SrRNA-based PCR. The clonal similarities of the bacteria were detected in the samples which the same bacteria had been detected in each samples of the same child. After DNA sequencing, clonal similarity was determined by 16SrRNA gene clone library analysis. The sequences from each clone were compared with similar sequences of reference organisms by FASTA search. Results: T. denticola was detected only in four (20%) saliva and in one (5%) nasopharyngeal sample. F. nucleatum was detected in 11 (55%) saliva, eight (40%) nasopharyngeal and six (30%) middle ear effusion samples. Sequences from F.nucleatum clones derived from three different anatomic sites within patients were similar in 33% of OME patients, indicating their genetic relatedness. Conclusions: Bacteria involved in this process most likely originate from the oropharynx since they show a close genetic relatedness with their oropharyngeal counterparts.

An assessment of antibacterial activity of three pulp capping materials on Enterococcus faecalis by a direct contact test: An in vitro study.

Objective: The aim of this in vitro study was to evaluate antimicrobial activities of three different pulp capping materials; Biodentine, mineral trioxide aggregate (MTA) Angelus, and Dycal against Enterococcus faecalis and their durability with time. Materials and Methods : Direct contact test was used for the assessment. Three sets of sealers were mixed and placed on microtiter plate wells: One set was used within 20 min of recommended setting time while others were used after 24-h and 1-week. E. faecalis suspension was placed directly on the materials for 1 h and then transferred to another plate with fresh media. Nine wells of bacteria without the tested cements served as the positive control. One well of the tested cements without bacteria served as the negative control. Bacterial growth was evaluated by a temperature-controlled microplate spectrophotometer for 1-h intervals among 24 h. Data were analyzed using Kruskal-Wallis test. Results: All tested materials showed less bacterial density than the control group. MTA, Biodentine, and Dycal showed significantly higher bacterial density than the control group in freshly mixed samples (P < 0.05). And MTA showed significantly higher antibacterial activity than Dycal (P < 0.05). In 24 h, materials did not show any differences (P > 0.05). MTA and Biodentine samples showed significant differences than Dycal; MTA also showed higher antibacterial activity than control in 1-week samples (P < 0.05). Conclusion: While freshly mixed MTA showed the best antibacterial activity over time, Biodentine had shown similar antibacterial activity to MTA.

Decontamination of autogenous bone grafts collected during dental implant site preparation: a pilot study.

Dental implant site preparation produces bone particles that can be used as autogenous bone graft material for the reconstruction of alveolar bone defects; however, collected bone particles are contaminated with oral microorganisms that may cause augmentation failure due to complications associated with infection. The stringent aspiration protocol, preoperative oral chlorhexidine rinsing, and antibiotic prophylaxis were implemented before collecting bone particles. Nonetheless, collected bone particles were still contaminated with bacteria, and, therefore, decontamination of the collected bone particles with chlorhexidine or clindamycin was considered. The aims of this study were to quantitatively determine the degree of bacterial contamination of collected bone particles and to quantitatively evaluate the efficacy of treating collected bone particles with clindamycin or chlorhexidine solutions. Both of the agents effectively decontaminated the collected bone particles. Comparison between these antimicrobials in further studies could be useful in determining which is most effective.

Staphylococcus aureus transmission through oronasal fistula in children with cleft lip and palate.

Objective: To determine the presence of Staphylococcus aureus in a nasal flora and oral environment, the correlation between frequency of transmission of S. aureus and oronasal fistula size, and the pattern of methicillin resistance on S. aureus strains in children with cleft lip and palate (CLP). Design: Thirty-two CLP children with and without oronasal fistulas, ranging in age from 5 to 13 years were examined for oronasal fistula presence and size. Stimulated saliva samples and nasal swab samples were taken and investigated for S. aureus presence. S. aureus presence and counts were correlated with fistula presence and size. Results: Saliva samples showed statistical differences between the groups with and without oronasal fistulas with an area ranging from 0.80 to 28.26 mm2. The S. aureus counts were significantly higher (r  =  .535, p  =  .002) in saliva samples from children with larger oronasal fistula. The S. aureus count was not significantly different (r  =  –.013, p  =  .942) in nasal samples compared with oronasal fistula size. Methicillin resistance with disk-diffusion method was recorded as sensitive (≥13 mm) in all S. aureus strains. Conclusions: The results of this study indicate a positive correlation between fistula size and S. aureus transmission to one oral environment through oronasal fistulae, and a positive correlation between frequency of S. aureus transmission and fistula size. All S. aureus strains were sensitive to methicillin. These results may have implications for preventive treatment of CLP children.

Development of novel formulations containing Lysozyme and Lactoferrin and evaluation of antibacterial effects on Mutans Streptococci and Lactobacilli.

OBJECTIVE The aim of this study was to determine the antibacterial effect of different formulations containing Lysozyme and Lactoferrin and drug delivery system as well as poloxamer 407 with the trade name of Pluronic F-127 and/or freeze dried liposome containing DOTAP [freeze dried Liposomal DOTAP] on Streptococcus sobrinus, Streptococcus mutans and Lactobacillus acidophilus in comparison with 0.2% chlorhexidine. MATERIALS AND METHODS The antibacterial effect was assessed by determining the minimum inhibitory concentrations (MIC) for the study and control groups on Streptococcus sobrinus, Streptococcus mutans and Lactobacillus acidophilus. The amounts of biofilm formation accumulation of Mutans Streptococci for 24h on sterile hydroxyapatite discs after application of different formulations were evaluated. The different formulations studied were: (1) Sorensens Buffer Solution, (2) a gel formulation containing only poloxamer 407, (3) Lysozyme and Lactoferrin dissolved in Sorensens Buffer Solution, (4) poloxamer 407 combined with the third formulation, (5) Freeze dried Liposomal DOTAP dissolved in Sorensens Buffer Solution, (6) Freeze dried Liposomal DOTAP combined with poloxamer 407 dispersed in Sorensens Buffer Solution, (7) Freeze dried Liposomal DOTAP combined with the third formulation, and (8) Lysozyme and Lactoferrin dissolved in Sorensens Buffer Solution, which was then incorporated into poloxamer 407 and combined with Freeze dried Liposomal DOTAP. The positive and negative control groups were 0.2% chlorhexidine gel and empty hydroxyapatite discs, respectively. Statistical evaluation was carried out with Kruskal-Wallis and Dunns multiple comparison tests. RESULTS It was observed that the first, third and fifth groups did not have any antibacterial effects on the tested bacteria. The groups that contained poloxamer 407 had nearly identical antibacterial effects on Mutans Streptococci and L. acidophilus. These formulations also inhibited biofilm formation of the bacteria (p<0.05) more effectively. In the positive control group, there was no biofilm formation. CONCLUSIONS Among the formulations containing poloxamer 407, the one containing Lysozyme and Lactoferrin exhibited the highest inhibitory effect on the tested bacteria. This novel formulation can be beneficial as an antibacterial agent for the prevention of dental caries and biofilm formation.