Microbiological effects of amoxicillin plus metronidazole in the treatment of young patients with Stages III and IV periodontitis: A secondary analysis from a 1-year double-blinded placebo-controlled randomized clinical trial.

BACKGROUND: Despite the body of evidence supporting the clinical benefits of metronidazole (MTZ) and amoxicillin (AMX) in the treatment of young patients with periodontitis, the microbiological outcomes of this antibiotic protocol have been less explored. This study evaluated the microbiological effects of adjunctive MTZ+AMX in the treatment of young patients with periodontitis. METHODS: Subjects with periodontitis Stages III or IV and ≤30 years old were randomly allocated to receive scaling and root planing (SRP) with placebo (n = 15) or with MTZ (400 mg) and AMX (500 mg) three times a day for 14 days (n = 15). Nine subgingival biofilm samples per subject (three samples from each probing depth (PD) category: ≤3, 4-6, and ≥7 mm) were collected at baseline and 3-, 6-, and 12-months post-treatment and individually analyzed for 40 bacterial species by checkerboard DNA-DNA hybridization. RESULTS: Thirty subjects (15/group) with mean ages 27.6 ± 3.5 (control) and 26.8 ± 3.9 (test) were included. At 12 months post-therapy, the antibiotic group harbored lower proportions of red complex (1.3%) than the placebo group (12.5%) (p < 0.05). SRP + MTZ+AMX was more effective than mechanical treatment in reducing levels/proportions of several pathogens and increasing proportions of Actinomyces species (p < 0.05). Levels/proportions of Aggregatibacter actinomycetemcomitans were only reduced in the antibiotic group (p < 0.05). This group also exhibited greater reduction in the number of sites with PD ≥5 mm and higher percentage of subjects reaching the clinical end point for treatment (≤4 sites with PD ≥5 mm) than the control group (p < 0.05). CONCLUSION: SRP+MTZ+AMX allowed for establishing a long-term healthier subgingival biofilm community and periodontal clinical condition, than SRP only.

In vitro antimicrobial effect of titanium anodization on complex multispecies subgingival biofilm.

Anodization is a routine industrial galvanic method that produces a titanium oxide layer on the surface of titanium. Considering the possibility that this technique could influence microbial adsorption and colonization, this in vitro study was conducted to evaluate the impact of a process of anodization applied to a titanium surface on the microbial profile of multispecies subgingival biofilm. Titanium discs produced by using two different processes-conventional and Anodization-were divided into two groups: conventional titanium discs with machined surface (cpTi) Control Group and titanium discs with anodic oxidation treatment (anTi) Test Group. Subgingival biofilm composed of 33 species was formed on the titanium discs that were positioned vertically in 96-well plates, for 7 days. The proportions and the counts of microbial species were determined using a DNA-DNA hybridization technique, and data were evaluated using Mann-Whitney test (p < 0.05). Mean total bacterial counts were lower in Test Group in comparison with Control Group (p < 0.05). Nine bacterial species differed significantly, and were found in higher levels in Control Group in comparison with Test Group, including T. forsythia, E. nodatum, and F. periodonticum. In conclusion, titanium discs with anodization could alter the microbial profile of the biofilm formed around them. Further clinical studies should be conducted to confirm the clinical impact of these findings.

Evaluation of the Microbiological Profile of Alveolar Residual Screws and Cleft-Adjacent Teeth in Individuals With Complete Unilateral Fissures.

OBJECTIVE: To evaluate the microbiota profile of residual alveolar slits and teeth adjacent to the cleft in fissured individuals. DESIGNS: This study used a cross-sectional design. PARTICIPANTS: Twenty individuals, aged 14 to 24 years, who had a residual fissure in the maxillary alveolar ridge region were selected. MAIN OUTCOME MEASURES: Three sites per individual were selected for microbiological collection (the site of the residual cleft and the 2 nearest teeth). The samples were analyzed using the Checkerboard DNA-DNA hybridization technique for 73 species of bacteria. RESULTS: All the species analyzed were found in the 2 niches (slits and teeth). The bacterial species present in the largest number in the residual cracks were Prevotella melaninogenica, Prevotella nigrescens, and Streptococcus mitis. With regard to the bacterial profiles in the mesial and distal faces, the most prevalent species were P nigrescens, Veillonella parvula, and Fusobacterium nucleatum sp vicentii. The analysis of all the collected samples demonstrated very similar profiles for the mesial and distal faces, with these 2 sites even presenting the same species in greater frequencies. Higher counts of 20 bacterial species (Wilcoxon test) were observed in the dental niche, in relation to the fissure, particularly, P nigrescens, V parvula, F nucleatum sp vicentii, and Neisseria mucosa. CONCLUSION: Some species were significantly more prevalent in the residual alveolar fissures and in adjacent teeth. The comparison between the profiles of the 2 niches demonstrated large differences in the most frequent species in the teeth, and no qualitative differences with regard to specific pathogens.

Brazilian Red Propolis Is as Effective as Amoxicillin in Controlling Red-Complex of Multispecies Subgingival Mature Biofilm In Vitro.

This study investigated the effects of Brazilian Red Propolis (BRP) extract on seven-day-old multispecies subgingival biofilms. Mixed biofilm cultures containing 31 species associated with periodontal health or disease were grown for six days on a Calgary device. Then, mature biofilms were treated for 24 h with BRP extract at different concentrations (200-1600 µg/mL), amoxicillin (AMOXI) at 54 µg/mL (positive control) or vehicle (negative control). Biofilm metabolic activity was determined by colorimetry, and bacterial counts/proportions were determined by DNA-DNA hybridization. Data were analyzed by Kruskal-Wallis and Dunn's tests. Treatment with BRP at 1600, 800 and 400 µg/mL reduced biofilm metabolic activity by 56%, 56% and 57%, respectively, as compared to 65% reduction obtained with AMOXI. Mean total cell counts were significantly reduced in all test groups (~50-55%). Lower proportions of red, green and yellow complex species were observed upon treatment with BRP (400 µg/mL) and AMOXI, but only AMOXI reduced the proportions of Actinomyces species. In conclusion, BRP extract was as effective as AMOXI in killing seven-day-old multispecies biofilm pathogens and did not affect the levels of the host-compatible Actinomyces species. These data suggest that BRP may be an alternative to AMOXI as an adjunct in periodontal therapy. In vivo studies are needed to validate these results.

Antimicrobial photodynamic therapy as adjunct to non-surgical periodontal treatment in smokers: a randomized clinical trial.

OBJECTIVES: This study aims to investigate the additional influence of multiple applications of antimicrobial photodynamic therapy (aPDT) in smokers with chronic periodontitis. MATERIALS AND METHODS: Twenty smokers with chronic periodontitis were treated in a split-mouth design study with aPDT adjunct to Scaling and Root Planing (SRP) or SRP. aPDT was performed by using a laser light source with 660 nm wavelength associated with a photosensitizer. The applications were performed in four episodes (at days 0, 2, 7, and 14). All patients were monitored for 90 days. Plaque index, probing depth, clinical attachment level, and bleeding on probing were performed at baseline, 30, and 90 days after the SRP. Gingival crevicular fluid and subgingival plaque samples were collected for immunological and microbiological analysis, respectively. Data obtained were statistically analyzed. RESULTS: aPDT as an adjunct to SRP did not demonstrate statistically significant advantages on clinical parameters when compared with SRP alone. No statistic significant differences between groups were observed (p < 0.05). Levels of anti-inflammatory cytokines and bacterial species were comparable in both groups at day 90 after treatment. CONCLUSION: Periodontal treatment with SRP + aPDT in multiples episodes was not able to promote additional clinical, immunological, and microbiological benefits in smokers when compared SRP alone in patients with chronic periodontitis. CLINICAL RELEVANCE: Multiple episodes of aPDT adjunctive to non-surgical treatment did not improve significantly the clinical, immunological, and microbiological parameters when compared with SRP alone. More randomized clinical trials are needed to evaluate adjuvant therapies for scaling and root planning in smokers with chronic periodontitis. ClinicalTrials.gov Identifier: NCT03039244.

The ideal time of systemic metronidazole and amoxicillin administration in the treatment of severe periodontitis: study protocol for a randomized controlled trial.

BACKGROUND: The combination of systemic metronidazole (MTZ) and amoxicillin (AMX) with scaling and root planing (SRP) has shown to be an effective periodontal treatment. However, some essential issues associated with the use of these antibiotics remain unanswered, such as the ideal time of administration during the course of periodontal treatment. Although these agents are often prescribed after the healing phase of the SRP procedure, there is biological plausibility to support its use in conjunction with the mechanical treatment. However, to date, no placebo controlled randomized clinical trial (RCT) has directly compared these two protocols. Therefore, the aim of this RCT is to compare the clinical, microbiological and immunological effects of the adjunctive systemic MTZ + AMX administered in different phases of the treatment of severe periodontitis. METHODS: Subjects with severe periodontitis (n = 180) are being randomly assigned into three groups (n = 60/group): (i) SRP-only (control group), SRP in combination with 400 mg MTZ + 500 mg AMX, starting (ii) at the first SRP session (active phase group), or (iii) after 3 months of its completion (healing phase group). All volunteers are receiving clinical and microbiological evaluation at baseline, 3, 6 and 12 months, and immunological assessment at baseline and 12 months post-therapy. Nine subgingival biofilm samples are being collected per subject and analyzed for counts and proportions of 40 bacterial species by checkerboard DNA-DNA hybridization, and six gingival crevicular fluid samples are being collected and analyzed for the levels of 20 chemokines by multiplex immunoassay. The primary outcome variable is the number of volunteers reaching the clinical endpoint for treatment (≤ 4 sites with probing depth ≥5 mm) at 1 year post-therapy. Differences in clinical, microbiological and immunological parameters among groups and over time will be evaluated using analysis of variance, analysis of covariance and the Chi-square and Tukey tests. Microbiological and immunological analyses will be performed using adjustments for multiple comparisons. Statistical significance will be set at 5%. TRIAL REGISTRATION: ClinicalTrials.gov , NCT02954393 . Registered on 3 November 2016.

Microbial reduction by two chemical-mechanical protocols in primary teeth with pulp necrosis and periradicular lesion - an in vivo study.

The objective of this study was to determine the efficacy of chemical-mechanical procedures of two endodontic protocols for septic content reduction of root canals from primary teeth with pulp necrosis and periradicular lesion. Twenty-four primary root canals with pulp necrosis and periradicular lesion were divided into two treatment groups (n=12): multiple-visit and single-visit protocols. Samples were collected using sterile paper points before and after endodontic cleaning followed by microbiological identification through checkerboard DNA-DNA hybridization. Statistical analysis was performed using Proportion Test for score=0 comparing the findings before and after treatment for each group (Wilcoxon's test) as well as the differences in scores between protocols (Mann-Whitney's test) (p<0.05). Data were expressed as prevalence (presence or absence) and estimate of the average count (x10(5) cells) of each species. Differences in proportions of score=0 prior to treatment were non-significant (p=0.415), demonstrating equivalence between groups. A significant increase in score=0 was detected after treatment for both groups (p<0.0001). Single-visit protocol achieved a significantly greater reduction in mean scoring following endodontic treatment (p=0.024). Both protocols were capable of significantly reducing septic content in root canals of primary teeth with periradicular lesion. Moreover, single-visit protocol showed greater efficacy in reducing endodontic infection.

Microbial profile of root canals of primary teeth with pulp necrosis and periradicular lesion.

PURPOSE: The purpose of this study was to assess the microbial content of root canals of human primary teeth with pulp necrosis and periradicular lesion. METHODS: Microbial samples were collected from 24 canals of children treated at a pediatric dentistry clinic. Microbiological identification was performed using checker-board DNA-DNA hybridization for 40 different bacteria. Data were analyzed per canal based on the mean count and frequency of each bacterial species. RESULTS: Detectable levels of bacterial species were observed for 35 probes (88%). The most frequent bacteria were Fusobacterium nucleatum sp. nucleatum, Fusobacterium periodonticum, Prevotella melaninogenica, Prevotella nigrescens, and Prevotella intermedia. Facultative species were identified in 20 root canals (83%), anaerobic species were identified in 24 root canals (100%), and aerobic species in 18 root canals (75%). Black-pigmented bacilli were found in 23 samples (96%). The number of different bacterial species detected per canal ranged from five to 33. CONCLUSION: Endodontic infection in primary teeth with pulp necrosis and periradicular lesion is multimicrobial, including aerobic, facultative, and anaerobic micro-organisms.

Molecular detection of in-vivo microbial contamination of metallic orthodontic brackets by checkerboard DNA-DNA hybridization.

INTRODUCTION: Knowing the microbiota that colonizes orthodontic appliances is important for planning strategies and implementing specific preventive measures during treatment. The purpose of this clinical trial was to evaluate in vivo the contamination of metallic orthodontic brackets with 40 DNA probes for different bacterial species by using the checkerboard DNA-DNA hybridization (CDDH) technique. METHODS: Eighteen patients, 11 to 29 years of age having fixed orthodontic treatment, were enrolled in the study. Each subject had 2 new metallic brackets bonded to different premolars in a randomized manner. After 30 days, the brackets were removed and processed for analysis by CDDH. Data on bacterial contamination were analyzed descriptively and with the Kruskal-Wallis and Dunn post tests (α = 0.05). Forty microbial species (cariogenic microorganisms, bacteria of the purple, yellow, green, orange complexes, "red complex +Treponema socranskii," and the cluster of Actinomyces) were assessed. RESULTS: Most bacterial species were present in all subjects, except for Streptococcus constellatus, Campylobacter rectus, Tannerella forsythia, T socranskii, and Lactobacillus acidophillus (94.4%), Propionibacterium acnes I and Eubacterium nodatum (88.9%), and Treponema denticola (77.8%). Among the cariogenic microorganisms, Streptococcus mutans and Streptococcus sobrinus were found in larger numbers than L acidophillus and Lactobacillus casei (P <0.001). The periodontal pathogens of the orange complex were detected in larger numbers than those of the "red complex +T socranskii" (P <0.0001). Among the bacteria not associated with specific pathologies, Veillonella parvula (purple complex) was the most frequently detected strain (P <0.0001). The numbers of yellow and green complex bacteria and the cluster of Actinomyces were similar (P >0.05). CONCLUSIONS: Metallic brackets in use for 1 month were multi-colonized by several bacterial species, including cariogenic microorganisms and periodontal pathogens, reinforcing the need for meticulous oral hygiene and additional preventive measures to maintain oral health in orthodontic patients.

Changes in the subgingival biofilm composition after coronally positioned flap.

OBJECTIVES: This study evaluated the effects of coronally positioned flap (CPF) on the subgingival biofilm composition. MATERIAL AND METHODS: Twenty-two subjects with gingival recessions were treated with CPF. Clinical parameters were assessed before and at 6 months after surgery. Subgingival biofilms were analyzed by checkerboard DNA-DNA hybridization technique for 40 bacterial species. RESULTS: Recession height, clinical attachment level and bleeding on probing improved significantly (p<0.05) at 6 months post-CPF. The proportions of 10 periodontal pathogens and the proportions of red and orange complexes decreased at 6 months. CONCLUSION: In conclusion, CPF can induce beneficial effects on the composition of the subgingival microbiota after 6 months.

Human peri-implant bone response to turned and oxidized titanium implants inserted and retrieved after 2 months.

PURPOSE: The aim of this study was to evaluate the influence of oxidized surface on bone-to-implant contact percentage (BIC%) as well as the bone density within the threads area (BD%) in human bone after 2 months of unloaded healing. MATERIALS: Seven subjects (mean age 45.57 +/- 10.45 years) received 2 micro-implants each during conventional implant surgery in the posterior maxilla. The implants that presented turned and oxidized surfaces served as control and test, respectively. After the healing period, the implants and the surrounding tissue were removed and prepared for ground sectioning and analysis. RESULTS: Two turned implants were found to be clinically unstable at the time of retrieval. Histometric evaluation showed that the mean of BIC% was 17.40 +/- 14.16% and 32.19 +/- 15.68% to turned and oxidized surfaces, respectively. The BD% was 22.13 +/- 19.06% for turned surface and 50.40 +/- 18.35% for oxidized surface. CONCLUSION: The histologic data from this preliminary study suggest that the oxidized micro-implants surface presented better mean values of BIC% and BD% than turned micro-implants after a short healing time.

Histological comparison of bone to implant contact in two types of dental implant surfaces: a single case study.

AIM: The purpose of this single case study was to evaluate the influence of different implant surfaces on human bone and osseointegration. METHODS AND MATERIALS: A 47-year-old partially edentulous woman received two experimental implants along with conventional implant therapy. Experimental implants placed in the mandibular ramus consisted of machined and anodized surfaces, respectively. After three months of healing, the experimental implants were removed and prepared for ground sectioning and histological analysis. RESULTS: The data demonstrate anodized implant surfaces present a higher percentage of osseointegration when compared to a machined surface in cortical human bone after a healing period of three months. CONCLUSION: This single case study suggests an anodized implant surface results in a higher percentage of bone to implant contact when compared to machined surfaced implants when placed in dense bone tissue. However, further investigations should be conducted.

Influence of implant surface topography on early osseointegration: a histological study in human jaws.

The purpose of this study was to evaluate the influence of the oxidized surface on bone-to-implant contact (BIC%), the bone density in the threaded area (BA%), as well as the bone density outside the threaded area (BD%) in human jaws after 2 months of unloaded healing. Thirteen subjects (mean age 42.61 +/- 6.15 years) received two microimplants (2.5 mm diameter and 6 mm length) each, during conventional mandible or maxilla implant surgery. The microimplants with commercially pure titanium surfaces (machined) and oxidized surfaces served as the control and test surfaces, respectively. After 2 months, the microimplants and the surrounding tissue were removed and prepared for histomorphometric analysis. All microimplants, except two machined and one oxidized microimplant surfaces, were found to be clinically stable after the healing period. Histometric evaluation indicated that the mean BIC% was (21.71 +/- 13.11)% and (39.04 +/- 15.75)% for machined and oxidized microimplant surfaces, respectively. The BD% was higher for the oxidized surface, although there was no difference for maxilla and mandible. The oxidized surface impacted the BA% for the type-IV bone. Data suggest that the oxidized surface presented a higher bone-to-implant contact rate compared with machined surfaces under unloaded conditions, after a healing period of 2 months.

Histologic evaluation of early human bone response to different implant surfaces.

BACKGROUND: Studies have demonstrated that roughened dental implant surfaces show firmer bone fixation and an increased percentage of bone-to-implant contact (BIC%) compared to commercially pure titanium-surface (machined) implants. Therefore, the purpose of this study was to evaluate the influence of implant-surface topography on human bone tissue after 2 months of unloaded healing. METHODS: Fourteen subjects with a mean age of 46.87 +/- 9.45 years received two microimplants each (2.5 mm in diameter and 6 mm in length), one test (sandblasted acid-etched surface) and one control (machined surface), either in the mandible or in the maxilla. After a healing period of 2 months, the microimplants and surrounding tissues were removed with a trephine bur and prepared for histologic analysis. RESULTS: All microimplants, except for one of the controls, were clinically stable after the healing period. Histometric evaluation indicated that the mean BIC% was 23.08% +/- 11.95% and 42.83% +/- 9.80% for machined and rough microimplant surfaces, respectively (P = 0.0005). The bone area within the threads was also higher for sandblasted-surface implants (P = 0.0005). The mean percentage of bone density did not differ between the two groups (P = 0.578). CONCLUSION: Data from the present histological study suggest that the sandblasted acid-etched implant provides a better human bone tissue response than machined implants under unloaded conditions after a healing period of 2 months.

Microbiota of the dorsum of the tongue after plaque accumulation: an experimental study in humans.

BACKGROUND: The purpose of the present investigation was to determine the effect of the absence of tongue hygiene on the microbiota of the dorsum of the tongue. METHODS: Ten volunteers (aged 19 to 22 years) entered the study at baseline and were instructed to abstain from tongue cleaning for 7 days, followed by a period of 3 days without any kind of oral hygiene. Subsequently, a period of 21 days of washout was employed, and this protocol was repeated three times. Microbiological samples were obtained from the dorsum of the tongue at baseline and at the end of the period of coating accumulation and analyzed using the checkerboard DNA-DNA hybridization technique. RESULTS: The species found in highest mean counts at baseline and day 10 were Prevotella melaninogenica and Veillonella parvula. The mean bacterial total counts enhanced significantly during the study (from 17.1x10(6) to 33.7x10(6)). Proportions of red and blue complexes and levels of 18 species also increased after the period of coating accumulation, including several periodontal pathogens, such as Prevotella intermedia, Prevotella nigrescens, Streptococcus constellatus, Tannerella forsythensis, Porphyromonas gingivalis, Treponema denticola, and P. melaninogenica. CONCLUSION: The tongue surface could be an important reservoir for periodontal pathogens and may play a role in the recolonization of tooth surfaces and in the etiology of oral halitosis.

Scaling and root planing and chlorhexidine mouthrinses in the treatment of chronic periodontitis: a randomized, placebo-controlled clinical trial.

OBJECTIVE: Evaluation of the clinical and microbiological effects of scaling and root planing (SRP) alone or in combination with 0.12% chlorhexidine (CHX) rinsing. METHODS: A blind, placebo-controlled, parallel-design, randomized clinical trial was conducted in 29 subjects with chronic periodontitis. Subjects were assigned to two therapeutic groups: control (SRP+placebo) and test (SRP+CHX during and up to 42 days post-therapy). Clinical and microbiological [N-benzoyl-dl-arginine-2-naphthylamide (BANA test)] examinations were performed at baseline, 42 and 63 days post-therapy. RESULTS: Initially, intermediate sites (4-6 mm) in the test group showed less plaque accumulation, gingival bleeding, bleeding on probing and a greater reduction in attachment level and probing depth (PD) at 63 days after treatment. The initially deep sites (>6 mm) in the CHX group also showed a better reduction in plaque accumulation and in PD compared with the control group. Both therapies led to a microbiological improvement; however, the test subjects showed a higher frequency of BANA-negative sites after treatment, which was sustained over time (p<0.001). At 63 days, the control group presented 25 BANA-negative sites and 65 positive sites, and the test group 58 and 26, respectively. CONCLUSION: The combination of CHX rinses and SRP leads to clinical benefits and to a better reduction in BANA-positive species.